Details of a Researcher - KOJIMA Takashi

Papers - KOJIMA Takashi

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The roles of tight junction protein cingulin in human endometrioid endometrial cancer.

Arisa Kura, Kimihito Saito, Takumi Konno, Takayuki Kohno, Hiroshi Shimada, Tadahi Okada, Soshi Nishida, Daichi Ishii, Motoki Matsuura, Tsuyoshi Saito, Takashi Kojima

Tissue barriers 2361976 - 2361976 2024.06 [International journal]

The bicellular tight junction molecule cingulin (CGN) binds to microtubules in centrosomes. Furthermore, CGN contributes to the tricellular tight junction (tTJ) proteins lipolysis-stimulated lipoprotein receptor (LSR) and tricellulin (TRIC). CGN as well as LSR decreased during the malignancy of endometrioid endometrial cancer (EEC). Although tTJ protein LSR is involved in the malignancy of some cancers, including EEC, the role of CGN is unknown. In this study, we investigated the roles of CGN with tTJ proteins in human EEC cells by using the CGN-overexpressing EEC cell line Sawano. In 2D cultures, CGN was colocalized with LSR and TRIC at tTJ or at γ-tubulin-positive centrosomes. In immunoprecipitation with CGN antibodies, CGN directly bound to LSR, TRIC, and β-tubulin. Knockdown of CGN by the siRNA decreased the epithelial barrier and enhanced cell proliferation, migration and invasion, as well as knockdown of LSR. In the Sawano cells cocultured with normal human endometrial stromal cells, knockdown of CGN decreased expression of LSR and TRIC via MAPK and AMPK pathways. In 2.5D cultures, knockdown of CGN induced the formation of abnormal cysts and increased the permeability of FD-4 to the lumen. In 2D and 2.5D cultures, treatment with β-estradiol with or without EGF or TGF-β decreased CGN expression and the epithelial permeability barrier and enhanced cell migration, and pretreatment with EW7197+AG1478, U0126 or an anti-IL-6 antibody prevented this. In conclusion, CGN, with tTJ proteins might suppress the malignancy of human EEC and its complex proteins are sensitive to estrogen and growth factors derived from stromal cells.

The Roles and Regulatory Mechanisms of Tight Junction Protein Cingulin and Transcription Factor Forkhead Box Protein O1 in Human Lung Adenocarcinoma A549 Cells and Normal Lung Epithelial Cells.

Daichi Ishii, Yuma Shindo, Wataru Arai, Takumi Konno, Takayuki Kohno, Kazuya Honda, Masahiro Miyajima, Atsushi Watanabe, Takashi Kojima

International journal of molecular sciences 25 ( 3 ) 2024.01 [International journal]

Tight junction (TJ) protein cingulin (CGN) and transcription factor forkhead box protein O1 (FOXO1) contribute to the development of various cancers. Histone deacetylase (HDAC) inhibitors have a potential therapeutic role for some cancers. HDAC inhibitors affect the expression of both CGN and FOXO1. However, the roles and regulatory mechanisms of CGN and FOXO1 are unknown in non-small cell lung cancer (NSCLC) and normal human lung epithelial (HLE) cells. In the present study, to investigate the effects of CGN and FOXO1 on the malignancy of NSCLC, we used A549 cells as human lung adenocarcinoma and primary human lung epithelial (HLE) cells as normal lung tissues and performed the knockdown of CGN and FOXO1 by siRNAs. Furthermore, to investigate the detailed mechanisms in the antitumor effects of HDAC inhibitors for NSCLC via CGN and FOXO1, A549 cells and HLE cells were treated with the HDAC inhibitors trichostatin A (TSA) and Quisinostat (JNJ-2648158). In A549 cells, the knockdown of CGN increased bicellular TJ protein claudin-2 (CLDN-2) via mitogen-activated protein kinase/adenosine monophosphate-activated protein kinase (MAPK/AMPK) pathways and induced cell migration, while the knockdown of FOXO1 increased claudin-4 (CLDN-4), decreased CGN, and induced cell proliferation. The knockdown of CGN and FOXO1 induced cell metabolism in A549 cells. TSA and Quisinostat increased CGN and tricellular TJ protein angulin-1/lipolysis-stimulated lipoprotein receptor (LSR) in A549. In normal HLE cells, the knockdown of CGN and FOXO1 increased CLDN-4, while HDAC inhibitors increased CGN and CLDN-4. In conclusion, the knockdown of CGN via FOXO1 contributes to the malignancy of NSCLC. Both HDAC inhibitors, TSA and Quisinostat, may have potential for use in therapy for lung adenocarcinoma via changes in the expression of CGN and FOXO1.

The interplay between the epithelial permeability barrier, cell migration and mitochondrial metabolism of growth factors and their inhibitors in a human endometrial carcinoma cell line.

Takumi Konno, Takayuki Kohno, Shin Kikuchi, Arisa Kura, Kimihito Saito, Tadahi Okada, Hiroshi Shimada, Yuya Yamazaki, Tomoki Sugiyama, Motoki Matsuura, Yuki Ohsaki, Tsuyoshi Saito, Takashi Kojima

Tissue barriers 2304443 - 2304443 2024.01 [International journal]

It is known that there are abnormalities of tight junction functions, cell migration and mitochondrial metabolism in human endometriosis and endometrial carcinoma. In this study, we investigated the effects of growth factors and their inhibitors on the epithelial permeability barrier, cell migration and mitochondrial metabolism in 2D and 2.5D cultures of human endometrioid endometrial carcinoma Sawano cells. We also investigated the changes of bicellular and tricellular tight junction molecules and ciliogenesis induced by these inhibitors. The growth factors TGF-β and EGF affected the epithelial permeability barrier, cell migration and expression of bicellular and tricellular tight junction molecules in 2D and 2.5D cultures of Sawano cells. EW-7197 (a TGF-β receptor inhibitor), AG1478 (an EGFR inhibitor) and SP600125 (a JNK inhibitor) affected the epithelial permeability barrier, cell migration and mitochondrial metabolism and prevented the changes induced by TGF-β and EGF in 2D and 2.5D cultures. EW-7197 and AG1478 induced ciliogenesis in 2.5D cultures. In conclusion, TGF-β and EGF promoted the malignancy of endometrial cancer via interplay among the epithelial permeability barrier, cell migration and mitochondrial metabolism. EW-7197 and AG1478 may be useful as novel therapeutic treatments options for endometrial cancer.

Downregulation of angulin-1/LSR induces malignancy via upregulation of EGF-dependent claudin-2 and TGF-β-dependent cell metabolism in human lung adenocarcinoma A549 cells.

Wataru Arai, Takumi Konno, Takayuki Kohno, Yuki Kodera, Mitsuhiro Tsujiwaki, Yuma Shindo, Hirofumi Chiba, Masahiro Miyajima, Yuji Sakuma, Atsushi Watanabe, Takashi Kojima

Oncotarget 14 261 - 275 2023.03 [International journal]

Abnormal expression of bicellular tight junction claudins, including claudin-2 are observed during carcinogenesis in human lung adenocarcinoma. However, little is known about the role of tricellular tight junction molecule angulin-1/lipolysis-stimulated lipoprotein receptor (LSR). In the lung adenocarcinoma tissues examined in the present study, expression of claudin-2 was higher than in normal lung tissues, while angulin-1/LSR was poorly or faintly expressed. We investigated how loss of angulin-1/LSR affects the malignancy of lung adenocarcinoma cell line A549 and normal human lung epithelial (HLE) cells. The EGF receptor tyrosine kinase inhibitor AG1478 prevented the increase of claudin-2 expression induced by EGF in A549 cells. Knockdown of LSR induced expression of claudin-2 at the protein and mRNA levels and AG1478 prevented the upregulation of claudin-2 in A549 cells. Knockdown of LSR induced cell proliferation, cell migration and cell metabolism in A549 cells. Knockdown of claudin-2 inhibited the cell proliferation but did not affect the cell migration or cell metabolism of A549 cells. The TGF-β type I receptor inhibitor EW-7197 prevented the decrease of LSR and claudin-2 induced by TGF-β1 in A549 cells and 2D culture of normal HLE cells. EW-7197 prevented the increase of cell migration and cell metabolism induced by TGF-β1 in A549 cells. EW-7197 prevented the increase of epithelial permeability of FITC-4kD dextran induced by TGF-β1 in 2.5D culture of normal HLE cells. In conclusion, downregulation of angulin-1/LSR induces malignancy via EGF-dependent claudin-2 and TGF-β-dependent cell metabolism in human lung adenocarcinoma.

Atypical Macropinocytosis Contributes to Malignant Progression: A Review of Recent Evidence in Endometrioid Endometrial Cancer Cells.

Takayuki Kohno, Takashi Kojima

Cancers 14 ( 20 ) 2022.10 [International journal]

Macropinocytosis is an essential mechanism for the non-specific uptake of extracellular fluids and solutes. In recent years, additional functions have been identified in macropinocytosis, such as the intracellular introduction pathway of drugs, bacterial and viral infection pathways, and nutritional supplement pathway of cancer cells. However, little is known about the changes in cell function after macropinocytosis. Recently, it has been reported that macropinocytosis is essential for endometrial cancer cells to initiate malignant progression in a dormant state. Macropinocytosis is formed by a temporary split of adjacent bicellular junctions of epithelial sheets, rather than from the apical surface or basal membrane, as a result of the transient reduction of tight junction homeostasis. This novel type of macropinocytosis has been suggested to be associated with the malignant pathology of endometriosis and endometrioid endometrial carcinoma. This review outlines the induction of malignant progression of endometrial cancer cells by macropinocytosis based on a new mechanism and the potential preventive mechanism of its malignant progression.

LSR antibody promotes apoptosis and disrupts epithelial barriers via signal pathways in endometrial cancer.

Kimihito Saito, Takumi Konno, Takayuki Kohno, Hiroshi Shimada, Motoki Matsuura, Tadahi Okada, Arisa Kura, Daichi Ishii, Masuo Kondoh, Tsuyoshi Saito, Takashi Kojima

Tissue barriers 2106113 - 2106113 2022.07 [International journal]

Lipolysis-stimulated lipoprotein receptor (LSR), a lipid metabolism-related factor localized in tricellular tight junctions (tTJs), plays an important role in maintaining the epithelial barrier. LSR is highly expressed in well-differentiated endometrial endometrioid carcinoma (EEC), and its expression decreases during malignancy. Angubindin-1, a novel LSR ligand peptide, regulates tTJs without cytotoxicity, enhances paracellular permeability, and regulates epithelial barrier via c-Jun N-terminal kinase (JNK)/cofilin. In this study, we investigated the immune-modulatory roles of an anti-LSR antibody in the treatment of EEC in vitro compared to those of angubindin-1. We prepared an antibody against the extracellular N-terminal domain of human LSR (LSR-N-ab) and angubindin-1. EEC cell-line Sawano cells in 2D and 2.5D cultures were treated with 100 μg/ml LSR-N-ab or 2.5 μg/ml angubindin-1 with or without protein tyrosine kinase 2β inhibitor PF431396 (PF43) and JNK inhibitor SP600125 (SP60) at 10 μM. Treatment with LSR-N-ab and angubindin-1 decreased LSR at the membranes of tTJs and the activity of phosphorylated LSR and phosphorylated cofilin in 2D culture. Treatment with LSR-N-ab and angubindin-1 decreased the epithelial barrier measured as TEER values in 2D culture and enhanced the epithelial permeability of FD-4 in 2.5D culture. Treatment with LSR-N-ab, but not angubindin-1, induced apoptosis in 2D culture. Pretreatment with PF43 and SP60 prevented all the changes induced by treatment with LSR-N-ab and angubindin-1. Treatment with LSR-N-ab and angubindin-1 enhanced the cell metabolism measured as the mitochondrial respiration levels in 2D culture. LSR-N-ab and angubindin-1 may be useful for therapy of human EEC via enhanced apoptosis or drug absorption.

Oxygen-Glucose Deprivation Decreases the Motility and Length of Axonal Mitochondria in Cultured Dorsal Root Ganglion Cells of Rats.

Shin Kikuchi, Takayuki Kohno, Takashi Kojima, Haruyuki Tatsumi, Yuki Ohsaki, Takafumi Ninomiya

Cellular and molecular neurobiology 2022.06 [International journal]

Controlling axonal mitochondria is important for maintaining normal function of the neural network. Oxygen-glucose deprivation (OGD), a model used for mimicking ischemia, eventually induces neuronal cell death similar to axonal degeneration. Axonal mitochondria are disrupted during OGD-induced neural degeneration; however, the mechanism underlying mitochondrial dysfunction has not been completely understood. We focused on the dynamics of mitochondria in axons exposed to OGD; we observed that the number of motile mitochondria significantly reduced in 1 h following OGD exposure. In our observation, the decreased length of stationary mitochondria was affected by the following factors: first, the halt of motile mitochondria; second, the fission of longer stationary mitochondria; and third, a transformation from tubular to spherical shape in OGD-exposed axons. Motile mitochondria reduction preceded stationary mitochondria fragmentation in OGD exposure; these conditions induced the decrease of stationary mitochondria in three different ways. Our results suggest that mitochondrial morphological changes precede the axonal degeneration while ischemia-induced neurodegeneration.

Inhibition of HDAC and Signal Transduction Pathways Induces Tight Junctions and Promotes Differentiation in p63-Positive Salivary Duct Adenocarcinoma.

Masaya Nakano, Kizuku Ohwada, Yuma Shindo, Takumi Konno, Takayuki Kohno, Shin Kikuchi, Mitsuhiro Tsujiwaki, Daichi Ishii, Soshi Nishida, Takuya Kakuki, Kazufumi Obata, Ryo Miyata, Makoto Kurose, Atsushi Kondoh, Kenichi Takano, Takashi Kojima

Cancers 14 ( 11 ) 2022.05 [International journal]

BACKGROUND: The p53 family p63 is essential for the proliferation and differentiation of various epithelial basal cells. It is overexpressed in several cancers, including salivary gland neoplasia. Histone deacetylases (HDACs) are thought to play a crucial role in carcinogenesis, and HDAC inhibitors downregulate p63 expression in cancers. METHODS: In the present study, to investigate the roles and regulation of p63 in salivary duct adenocarcinoma (SDC), human SDC cell line A253 was transfected with siRNA-p63 or treated with the HDAC inhibitors trichostatin A (TSA) and quisinostat (JNJ-26481585). RESULTS: In a DNA array, the knockdown of p63 markedly induced mRNAs of the tight junction (TJ) proteins cingulin (CGN) and zonula occuludin-3 (ZO-3). The knockdown of p63 resulted in the recruitment of the TJ proteins, the angulin-1/lipolysis-stimulated lipoprotein receptor (LSR), occludin (OCLN), CGN, and ZO-3 at the membranes, preventing cell proliferation, and leading to increased cell metabolism. Treatment with HDAC inhibitors downregulated the expression of p63, induced TJ structures, recruited the TJ proteins, increased the epithelial barrier function, and prevented cell proliferation and migration. CONCLUSIONS: p63 is not only a diagnostic marker of salivary gland neoplasia, but it also promotes the malignancy. Inhibition of HDAC and signal transduction pathways is, therefore, useful in therapy for p63-positive SDC cells.

FOXO3/TGF-β signal-dependent ciliogenesis and cell functions during differentiation of temperature-sensitive mouse cochlear precursor hair cells.

Takuya Kakuki, Takayuki Kohno, Soshi Nishida, Takumi Konno, Shin Kikuchi, Kizuku Ohwada, Masaya Nakano, Mitsuki Tezuka, Kenichi Takano, Takashi Kojima

Histochemistry and cell biology 157 ( 4 ) 415 - 426 2022.04 [Refereed] [International journal]

The transcription factor FOXO3 is necessary to preserve cochlear hair cells. Growth factors, including TGF-β, closely contribute to cochlear hair cell regeneration. In the present study, to investigate the roles of FOXO3 in the ciliogenesis and cell functions of cochlear hair cells, UB/OC-2 temperature-sensitive mouse cochlear precursor hair cells were treated with TGF-β receptor type 1 inhibitor EW-7197 or EGF receptor inhibitor AG-1478 after transfection with or without siRNA-FOXO3a. GeneChip analysis revealed that treatment with EW-7197 increased Foxo3 genes and decreased genes of Smads. During cell differentiation, treatment with EW-7197 or AG-1478 induced an increase in length of cilia-like structures that were positive for acetylated tubulin and inhibited cell migration. Treatment with EW-7197 also increased cell metabolism measured as mitochondrial basal respiration (oxygen consumption rate). The effects of EW-7197 were stronger than those of AG-1478. Knockdown of FOXO3 prevented the growth of cilia-like structures induced by EW-7197 or AG-1478 and induced cell migration under treatment with EW-7197. No change of the epithelial cell polarity molecule PAR3 was observed with any treatment. Treatment with the antimicrobial agent amikacin prevented the growth of cilia-like structures induced by EW-7197 and induced apoptosis. Pretreatment with the glucocorticoid dexamethasone inhibited the apoptosis induced by amikacin. This in vitro model of mouse cochlear hair cells suggests that FOXO3/TGF-β signaling plays a crucial role in ciliogenesis and cell functions during differentiation of cochlear hair cells. This model is useful for analysis of the mechanisms of hearing loss and to find therapeutic agents to prevent it.

The Roles of Tricellular Tight Junction Protein Angulin-1/Lipolysis-Stimulated Lipoprotein Receptor (LSR) in Endometriosis and Endometrioid-Endometrial Carcinoma.

Hiroshi Shimada, Takayuki Kohno, Takumi Konno, Tadahi Okada, Kimihito Saito, Yuma Shindo, Shin Kikuchi, Mitsuhiro Tsujiwaki, Marie Ogawa, Motoki Matsuura, Tsuyoshi Saito, Takashi Kojima

Cancers 13 ( 24 ) 2021.12 [International journal]

Tight junction proteins play roles beyond permeability barriers functions and control cell proliferation and differentiation. The relation between tight junctions and the signal transduction pathways affects cell growth, invasion and migration. Abnormality of tight junction proteins closely contributes to epithelial mesenchymal transition (EMT) and malignancy of various cancers. Angulin-1/lipolysis-stimulated lipoprotein receptor (LSR) forms tricellular contacts that has a barrier function. Downregulation of angulin-1/LSR correlates with the malignancy in various cancers, including endometrioid-endometrial carcinoma (EEC). These alterations have been shown to link to not only multiple signaling pathways such as Hippo/YAP, HDAC, AMPK, but also cell metabolism in ECC cell line Sawano. Moreover, loss of angulin-1/LSR upregulates claudin-1, and loss of apoptosis stimulating p53 protein 2 (ASPP2) downregulates angulin-1/LSR. Angulin-1/LSR and ASPP2 concentrate at both midbody and centrosome in cytokinesis. In EEC tissues, angulin-1/LSR and ASPP2 are reduced and claudin-2 is overexpressed during malignancy, while in the tissues of endometriosis changes in localization of angulin-1/LSR and claudin-2 are seen. This review highlights how downregulation of angulin-1/LSR promotes development of endometriosis and EEC and discusses about the roles of angulin-1/LSR and its related proteins, including claudins and ASPP2.

Dysfunction of epithelial permeability barrier induced by HMGB1 in 2.5D cultures of human epithelial cells.

Takashi Kojima, Yuma Shindo, Takumi Konno, Yuki Kodera, Wataru Arai, Maki Miyakawa, Kizuku Ohwada, Hiroki Tanaka, Mitsuhiro Tsujiwaki, Yuji Sakuma, Shin Kikuchi, Tsuyoshi Ohkuni, Kenichi Takano, Atsushi Watanabe, Takayuki Kohno

Tissue barriers 1972760 - 1972760 2021.09 [International journal]

Airway and intestinal epithelial permeability barriers are crucial in epithelial homeostasis. High mobility group box 1 (HMGB1), increased by various stimuli, is involved in the induction of airway inflammation, as well as the pathogenesis of inflammatory bowel disease. HMGB1 enhances epithelial hyperpermeability. Two-and-a-half dimensional (2.5D) culture assays are experimentally convenient and induce cells to form a more physiological tissue architecture than 2D culture assays for molecular transfer mechanism analysis. In 2.5D culture, treatment with HMGB1 induced permeability of FITC-dextran into the lumen formed by human lung, nasal and intestinal epithelial cells. The tricellular tight junction molecule angulin-1/LSR is responsible for the epithelial permeability barrier at tricellular contacts and contributes to various human airway and intestinal inflammatory diseases. In this review, we indicate the mechanisms including angulin-1/LSR and multiple signaling in dysfunction of the epithelial permeability barrier induced by HMGB1 in 2.5D culture of human airway and intestinal epithelial cells.

Translocation of LSR from tricellular corners causes macropinocytosis at cell-cell interface as a trigger for breaking out of contact inhibition.

Takayuki Kohno, Takumi Konno, Shin Kikuchi, Masuo Kondoh, Takashi Kojima

FASEB journal : official publication of the Federation of American Societies for Experimental Biology 35 ( 9 ) e21742 2021.09 [International journal]

Withdrawal from contact inhibition is necessary for epithelial cancer precursor cells to initiate cell growth and motility. Nevertheless, little is understood about the mechanism for the sudden initiation of cell growth under static conditions. We focused on cellular junctions as one region where breaking out of contact inhibition occurs. In well-differentiated endometrial cancer cells, Sawano, the ligand administration for tricellular tight junction protein LSR, which transiently decreased the robust junction property, caused an abrupt increase in cell motility and consequent excessive multilayered cell growth despite being under contact inhibition conditions. We observed that macropinocytosis essentially and temporarily occurred as an antecedent event for the above process at intercellular junctions without disruption of the junction apparatus but not at the apical plasma membrane. Collectively, we concluded that the formation of macropinocytosis, which is derived from tight junction-mediated signaling, was triggered for the initiation of cell growth in static precancerous epithelium.

Effects of HMGB1 on Tricellular Tight Junctions via TGF-β Signaling in Human Nasal Epithelial Cells.

Kizuku Ohwada, Takumi Konno, Takayuki Kohno, Masaya Nakano, Tsuyoshi Ohkuni, Ryo Miyata, Takuya Kakuki, Masuo Kondoh, Kenichi Takano, Takashi Kojima

International journal of molecular sciences 22 ( 16 ) 2021.08 [International journal]

The airway epithelium of the human nasal mucosa acts as a physical barrier that protects against inhaled substances and pathogens via bicellular and tricellular tight junctions (bTJs and tTJs) including claudins, angulin-1/LSR and tricellulin. High mobility group box-1 (HMGB1) increased by TGF-β1 is involved in the induction of nasal inflammation and injury in patients with allergic rhinitis, chronic rhinosinusitis, and eosinophilic chronic rhinosinusitis. However, the detailed mechanisms by which this occurs remain unknown. In the present study, to investigate how HMGB1 affects the barrier of normal human nasal epithelial cells, 2D and 2.5D Matrigel culture of primary cultured human nasal epithelial cells were pretreated with TGF-β type I receptor kinase inhibitor EW-7197 before treatment with HMGB1. Knockdown of angulin-1/LSR downregulated the epithelial barrier. Treatment with EW-7197 decreased angulin-1/LSR and concentrated the expression at tTJs from bTJs and increased the epithelial barrier. Treatment with a binder to angulin-1/LSR angubindin-1 decreased angulin-1/LSR and the epithelial barrier. Treatment with HMGB1 decreased angulin-1/LSR and the epithelial barrier. In 2.5D Matrigel culture, treatment with HMGB1 induced permeability of FITC-dextran (FD-4) into the lumen. Pretreatment with EW-7197 prevented the effects of HMGB1. HMGB1 disrupted the angulin-1/LSR-dependent epithelial permeability barriers of HNECs via TGF-β signaling in HNECs.

Effects of histone deacetylase inhibitors Tricostatin A and Quisinostat on tight junction proteins of human lung adenocarcinoma A549 cells and normal lung epithelial cells.

Yuma Shindo, Wataru Arai, Takumi Konno, Takayuki Kohno, Yuki Kodera, Hirofumi Chiba, Masahiro Miyajima, Yuji Sakuma, Atsushi Watanabe, Takashi Kojima

Histochemistry and cell biology 155 ( 6 ) 637 - 653 2021.06 [International journal]

Histone deacetylase (HDAC) inhibitors have a potential therapeutic role for non-small cell lung cancer (NSCLC). However, more preclinical studies of HDAC inhibitors in NSCLC and normal lung epithelial cells are required to evaluate their antitumor activities and mechanisms. The bicellular tight junction molecule claudin-2 (CLDN-2) is highly expressed in lung adenocarcinoma tissues and increase the proliferation of adenocarcinoma cells. Downregulation of the tricellular tight junction molecule angulin-1/LSR induces malignancy via EGF-dependent CLDN-2 and TGF-β-dependent cellular metabolism in human lung adenocarcinoma cells. In the present study, to investigate the detailed mechanisms of the antitumor activities of HDAC inhibitors in lung adenocarcinoma, human lung adenocarcinoma A549 cells and normal lung epithelial cells were treated with the HDAC inibitors Trichostatin A (TSA) and Quisinostat (JNJ-2648158) with or without TGF-β. Both HDAC inhibitors increased anguin-1/LSR, decrease CLDN-2, promoted G1 arrest and prevented the migration of A549 cells. Furthermore, TSA but not Quisinostat with or without TGF-β induced cellular metabolism indicated as the mitochondrial respiration measured using the oxygen consumption rate. In normal human lung epithelial cells, treatment with TSA and Quisinostat increased expression of LSR and CLDN-2 and decreased that of CLDN-1 with or without TGF-β in 2D culture. Quisinostat but not TSA with TGF-β increased CLDN-7 expression in 2D culture. Both HDAC inhibitors prevented disruption of the epithelial barrier measured as the permeability of FD-4 induced by TGF-β in 2.5D culture. TSA and Quisinostat have potential for use in therapy for lung adenocarcinoma via changes in the expression of angulin-1/LSR and CLDN-2.

Pyk2 inhibitor prevents epithelial hyperpermeability induced by HMGB1 and inflammatory cytokines in Caco-2 cells.

Takumi Konno, Takayuki Kohno, Maki Miyakawa, Hiroki Tanaka, Takashi Kojima

Tissue barriers 9 ( 2 ) 1890526 - 1890526 2021.04 [International journal]

The non-receptor protein tyrosine kinase 2β (Pyk2) phosphorylated tricellular tight junction (tTJ) molecules angulin-1/LSR and tricellulin (TRIC) and the inhibitor PF-431396 (PF43) suppress angulin-1/LSR and TRIC recruitment to tTJs. The disruption of the intestinal epithelial barrier by high mobility group box 1 (HMGB1) and the inflammatory cytokines TNFα and IFNγ contributes to downregulation of angulin-1/LSR and TRIC in 2.5D culture of Caco-2 cells as a novel model of inflammatory bowel disease (IBD). In the present study, to investigate the roles of Pyk2 phosphorylated angulin-1/LSR and TRIC in the intestinal epithelial barrier, 2D and 2.5D cultures of Caco-2 cells were treated with the Pyk2 inhibitor PF-43 with or without HMGB1, inflammatory cytokines TNFα and IFNγ. Treatment with PF-43 increased expression of angulin-1/LSR, phosphorylated AMPK and phosphorylated MAPK and decreased that of phosphorylated JNK, with upregulation of the epithelial barrier and cellular metabolism measured as basal oxygen consumption rate (OCR) and ATP production in 2D culture. Treatment with PF-43 prevented the downregulation of the epithelial barrier by HMGB1 and inflammatory cytokines in 2D culture. Treatment with PF-43 prevented the epithelial hyperpermeability induced by HMGB1 and inflammatory cytokines in 2.5D culture. In 2.5D culture, treatment with PF-43 inhibited the decreases of angulin-1/LSR, TRIC, pJNK, pAMPK and pMAPK induced by HMGB1 and the inflammatory cytokines. Treatment with PF-43 inhibited in part the induced phosphorylation of the serine of angulin-1/LSR and TRIC. Pyk2 inhibitor PF-43 may have potential for use in therapy for IBD via its actions with regard to phosphorylated tTJs and cellular metabolism.

HDAC inhibitors suppress the proliferation, migration and invasiveness of human head and neck squamous cell carcinoma cells via p63‑mediated tight junction molecules and p21‑mediated growth arrest.

Akito Kakiuchi, Takuya Kakuki, Kizuku Ohwada, Makoto Kurose, Atsushi Kondoh, Kazufumi Obata, Kazuaki Nomura, Ryo Miyata, Yakuto Kaneko, Takumi Konno, Takayuki Kohno, Tetsuo Himi, Ken-Ichi Takano, Takashi Kojima

Oncology reports 45 ( 4 ) 2021.04 [International journal]

In human head and neck squamous cell carcinoma (HNSCC), the invasion and metastatic properties of cancer cells are promoted by junctional adhesion molecule‑A (JAM‑A) and claudin‑1; these are epithelial tight junction molecules regulated by histone deacetylases (HDACs) and transcription factor p63. HDAC expression is reportedly upregulated in HNSCC, and HDAC inhibitors suppress cancer cell proliferation by initiating proliferative arrest or apoptosis. However, little is known of the anti‑cancer mechanisms of HDAC inhibitors in HNSCC. Thus, in the present study, the HNSCC Detroit 562 cell line and primary cultured HNSCC cells were treated with HDAC inhibitors to investigate their effects in HNSCC. Higher expression of p63, HDAC1, JAM‑A and claudin‑1 was observed in HNSCC tissues compared with the adjacent dysplastic regions. In Detroit 562 cells, treatment with trichostatin A (TSA), an inhibitor of HDAC1 and 6, downregulated the expression of p63, JAM‑A and claudin‑1, and upregulated that of acetylated tubulin; conversely, p63 knockdown resulted in the downregulation of JAM‑A and claudin‑1. Collectively, inhibiting HDAC suppressed the migration and invasiveness of cancer cells. In addition, treatment with TSA suppressed cancer cell proliferation via G2/M arrest, as well as upregulating p21 and downregulating cyclin D1 expression. TSA also downregulated the expression of epidermal growth factor receptor (EGFR) and phospho‑ERK1/2. p63 knockdown and treatment with an EGFR inhibitor induced G1 arrest and downregulated EGFR and phospho‑ERK1/2 levels, respectively. HDAC inhibition also suppressed the migration and invasiveness of primary cultured HNSCC cells. Collectively, the results of the present study indicate that HDAC inhibitors suppress the proliferation, migration and invasiveness of HNSCC by downregulating the p63‑mediated tight junction molecules JAM‑A and claudin‑1, and inducing p63 or p21‑mediated growth arrest.

Role of tight junctions in the epithelial-to-mesenchymal transition of cancer cells.

Daisuke Kyuno, Akira Takasawa, Shin Kikuchi, Ichiro Takemasa, Makoto Osanai, Takashi Kojima

Biochimica et biophysica acta. Biomembranes 1863 ( 3 ) 183503 - 183503 2021.03 [International journal]

The epithelial-mesenchymal transition (EMT) is an essential step in cancer progression. Epithelial cells possess several types of cell-cell junctions, and tight junctions are known to play important roles in maintaining the epithelial program. EMT is characterized by a loss of epithelial markers, including E-cadherin and tight junction proteins. Somewhat surprisingly, the evidence is accumulating that upregulated expression of tight junction proteins plays an important role in the EMT of cancer cells. Tight junctions have distinct tissue-specific and cancer-specific regulatory mechanisms, enabling them to play different roles in EMT. Tight junctions and related signaling pathways are attractive targets for cancer treatments; signal transduction inhibitors and monoclonal antibodies for tight junction proteins may be used to suppress EMT, invasion, and metastasis. Here we review the role of bicellular and tricellular tight junction proteins during EMT. Further investigation of regulatory mechanisms of tight junctions during EMT in cancer cells will inform the development of biomarkers for predicting prognosis as well as novel therapies.

Increase in Epithelial Permeability and Cell Metabolism by High Mobility Group Box 1, Inflammatory Cytokines and TPEN in Caco-2 Cells as a Novel Model of Inflammatory Bowel Disease.

Maki Miyakawa, Takumi Konno, Takayuki Kohno, Shin Kikuchi, Hiroki Tanaka, Takashi Kojima

International journal of molecular sciences 21 ( 22 ) 2020.11 [International journal]

High mobility group box 1 protein (HMGB1) is involved in the pathogenesis of inflammatory bowel disease (IBD). Patients with IBD develop zinc deficiency. However, the detailed roles of HMGB1 and zinc deficiency in the intestinal epithelial barrier and cellular metabolism of IBD remain unknown. In the present study, Caco-2 cells in 2D culture and 2.5D Matrigel culture were pretreated with transforming growth factor-β (TGF-β) type 1 receptor kinase inhibitor EW-7197, epidermal growth factor receptor (EGFR) kinase inhibitor AG-1478 and a TNFα antibody before treatment with HMGB1 and inflammatory cytokines (TNFα and IFNγ). EW-7197, AG-1478 and the TNFα antibody prevented hyperpermeability induced by HMGB1 and inflammatory cytokines in 2.5D culture. HMGB1 affected cilia formation in 2.5D culture. EW-7197, AG-1478 and the TNFα antibody prevented the increase in cell metabolism induced by HMGB1 and inflammatory cytokines in 2D culture. Furthermore, ZnSO4 prevented the hyperpermeability induced by zinc chelator TPEN in 2.5D culture. ZnSO4 and TPEN induced cellular metabolism in 2D culture. The disruption of the epithelial barrier induced by HMGB1 and inflammatory cytokines contributed to TGF-β/EGF signaling in Caco-2 cells. The TNFα antibody and ZnSO4 as well as EW-7197 and AG-1478 may have potential for use in therapy for IBD.

Possibility of Targeting Claudin-2 in Therapy for Human Endometrioid Endometrial Carcinoma.

Tadahi Okada, Takumi Konno, Takayuki Kohno, Hiroshi Shimada, Kimihito Saito, Seiro Satohisa, Tsuyoshi Saito, Takashi Kojima

Reproductive sciences (Thousand Oaks, Calif.) 27 ( 11 ) 2092 - 2103 2020.11 [International journal]

Claudin-2 (CLDN-2) is a leaky-type tight junction protein, and its overexpression increases tumorigenesis of some types of cancer cells. In the present study, to examine the possibility of targeting CLDN-2 in the therapy for endometrioid endometrial adenocarcinoma, we investigated the regulation and role of CLDN-2 in endometriosis and endometrioid endometrial adenocarcinoma. In endometrioid endometrial adenocarcinoma tissues, marked upregulation of CLDN-2 was observed together with malignancy, while in endometriosis tissues, a change in the localization of CLDN-2 was observed. In cells of the endometrial adenocarcinoma cell line Sawano, which highly express CLDN-2, downregulation of CLDN-2 induced by the siRNA upregulated the epithelial barrier and inhibited cell migration. Furthermore, the downregulation of CLDN-2 affected the cell cycle and inhibited cell proliferation. In Sawano cells cultured with high-glucose medium, CLDN-2 expression was downregulated at the mRNA and protein levels. The high-glucose medium upregulated the epithelial barrier, cell proliferation, and migration, and inhibited cell invasion. The histone deacetylase (HDAC) inhibitor tricostatin A (TSA), which has antitumor effects, downregulated CLDN-2 expression, cell proliferation, invasion, and migration, and upregulated the epithelial barrier. The mitochondrial respiration level, an indicator of cancer metabolism, was downregulated by CLDN-2 knockdown and upregulated by the high-glucose condition. Taken together, these results indicated that overexpression of CLDN-2 closely contributed to the malignancy of endometrioid endometrial adenocarcinoma. Downregulation of CLDN-2 via the changes of the glucose concentration and treatment with HDAC inhibitors may be important in the therapy for endometrial cancer.

HMGB1 enhances epithelial permeability via p63/TGF-β signaling in lung and terminal bronchial epithelial cells.

Yuki Kodera, Takayuki Kohno, Takumi Konno, Wataru Arai, Mitsuhiro Tsujiwaki, Yuma Shindo, Hirofumi Chiba, Maki Miyakawa, Hiroki Tanaka, Yuji Sakuma, Atsushi Watanabe, Hiroki Takahashi, Takashi Kojima

Tissue barriers 8 ( 4 ) 1805997 - 1805997 2020.10 [International journal]

High mobility group box 1 (HMGB1) is involved in the induction of airway inflammation and injury in patients with chronic obstructive pulmonary disease (COPD) and idiopathic pulmonary fibrosis (IPF). HMGB1 increased by transforming growth factor-β1 (TGF-β1), impairs airway epithelial barrier function in the lung. In the present study, to investigate how HMGB1 affects the barrier of normal human lung epithelial (HLE) cells, monolayer cells (2D culture) and bronchial-like spheroid cells (2.5 D Matrigel culture), which have lumen formation, were pretreated with TGF-β type I receptor kinase inhibitor EW-7197 before treatment with HMGB1. In 2D culture, treatment with HMGB1 decreased expression of angulin-1/LSR, TRIC and CLDN-1, -4, -7 and increased that of CLDN-2. Pretreatment with EW-7197 prevented the changes of all tight junction molecules induced by HMGB1. In 2.5D Matrigel culture, treatment with HMGB1 induced permeability of FITC-dextran (FD-4) into the lumen, whereas pretreatment with EW-7197 prevented the hyperpermeability of FD-4 into the lumen caused by HMGB1. In 2.5D Matrigel culture, knockdown of transcription factor p63 prevented the hyperpermeability induced by HMGB1 as well as pretreatment with EW-7197. In the 2D culture of HLE cells with HMGB1, knockdown of p63 increased the level of angulin-1/LSR and CLDN-4, while pretreatment with EW-7197 enhanced the increase of CLDN-4 induced by knockdown of p63. Immunohistochemical analysis of IPF, CLDN-2, HMGB1 and p63 revealed that their levels were higher in the regenerative epithelium of the terminal bronchial region than in normal epithelium. HMGB1 induces epithelial permeability of HLE cells via p63/TGF-β signaling in normal lung and IPF.

ASPP2 suppression promotes malignancy via LSR and YAP in human endometrial cancer.

Takumi Konno, Takayuki Kohno, Tadahi Okada, Hiroshi Shimada, Seiro Satohisa, Shin Kikuchi, Tsuyoshi Saito, Takashi Kojima

Histochemistry and cell biology 154 ( 2 ) 197 - 213 2020.08 [International journal]

Apoptosis-stimulating p53 protein 2 (ASPP2) is an apoptosis inducer that acts via binding with p53 and epithelial polarity molecule PAR3. Lipolysis-stimulated lipoprotein receptor (LSR) is an important molecule at tricellular contacts, and loss of LSR promotes cell migration and invasion via Yes-associated protein (YAP) in human endometrial cancer cells. In the present study, to find how ASPP2 suppression promotes malignancy in human endometrial cancer, we investigated its mechanisms including the relationship with LSR. In endometriosis and endometrial cancers (G1 and G2), ASPP2 was observed as well as PAR3 and LSR in the subapical region. ASPP2 decreased in G3 endometrial cancer compared to G1. In human endometrial cancer cell line Sawano, ASPP2 was colocalized with LSR and tricellulin at tricellular contacts and binding to PAR3, LSR, and tricellulin in the confluent state. ASPP2 suppression promoted cell migration and invasion, decreased LSR expression, and induced expression of phosphorylated YAP, claudin-1, -4, and -7 as effectively as the loss of LSR. Knockdown of YAP prevented the upregulation of pYAP, cell migration and invasion induced by the ASPP2 suppression. Treatment with a specific antibody against ASPP2 downregulated ASPP2 and LSR, affected F-actin at tricellular contacts, upregulated expression of pYAP and claudin-1, and induced cell migration and invasion via YAP. In normal human endometrial epithelial cells, ASPP2 was in part colocalized with LSR at tricellular contacts and knockdown of ASPP2 or LSR induced expression of claudin-1 and claudin-4. ASPP2 suppression promoted cell invasion and migration via LSR and YAP in human endometrial cancer cells.

HMGB1-downregulated angulin-1/LSR induces epithelial barrier disruption via claudin-2 and cellular metabolism via AMPK in airway epithelial Calu-3 cells.

Yuki Kodera, Hirofumi Chiba, Takumi Konno, Takayuki Kohno, Hiroki Takahashi, Takashi Kojima

Biochemical and biophysical research communications 527 ( 2 ) 553 - 560 2020.06 [International journal]

A non-histone chromatin-associated protein, high mobility group box 1 (HMGB1), which impairs the airway epithelial barrier, is involved in the induction of airway inflammation in patients with allergy, asthma, chronic obstructive pulmonary disease (COPD), and idiopathic pulmonary fibrosis (IPF). Tricellular tight junctions (tTJs) form at the convergence of bicellular tight junctions (bTJs). Angulin-1/lipolysis-stimulated lipoprotein receptor (LSR) is a novel molecule present at tricellular contacts and contributes to the epithelial barrier and cellular metabolism. Adenosine monophosphate-activated protein kinase (AMPK) is a central metabolic regulator and has a reciprocal association with TJs. In the present study, to examine how HMGB1 contributes to airway epithelial barrier disruption and the cellular metabolism indicated as mitochondrial respiration, bronchial epithelial Calu-3 cells were transfected with siRNAs of angulin-1/LSR or treated with HMGB1 and the relationship between HMGB1 and angulin-1/LSR was investigated. Knockdown of angulin-1/LSR upregulated the expression of the tight junction molecule claudin-2, AMPK activity, and mitochondrial respiration, and downregulated the epithelial barrier. Treatment with HMGB1 downregulated angulin-1/LSR expression and the epithelial barrier, and upregulated claudin-2 expression, AMPK activity and mitochondrial respiration. Treatment with EW-7197, a transforming growth factor-β (TGF-β) type I receptor kinase inhibitor, prevented all the effects of HMGB1 in Calu-3 cells. HMGB1-downregulated angulin-1/LSR induced epithelial barrier disruption via claudin-2 and cellular metabolism via AMPK in airway epithelial Calu-3 cells. The effects of HMGB1 contribute to TGF-β signaling and EW-7197 shows potential for use in therapy for HMGB1-induced airway inflammation.

Glucose-Dependent FOXM1 Promotes Epithelial-to-Mesenchymal Transition Via Cellular Metabolism and Targeting Snail in Human Pancreatic Cancer

Takuro Kyuno, Takayuki Kohno, Takumi Konno, Hiroshi Yamaguchi, Daisuke Kyuno, Masafumi Imamura, Yasutoshi Kimura, Takashi Kojima, Ichiro Takemasa

PANCREAS ( LIPPINCOTT WILLIAMS & WILKINS ) 49 ( 2 ) 273 - 280 2020.02 [Refereed]

ObjectivesTranscription factor Forkhead box protein M1 (FOXM1) plays critical roles in the progression of cancer including epithelial-to-mesenchymal transition (EMT). The aim of this study is to characterize the regulatory mechanisms of FOXM1 in EMT via pancreatic cancer metabolism.MethodsWe investigated the regulation of EMT via mitochondrial respiration by FOXM1 using pancreatic cancer cell lines HPAC and PANC-1 and normal human pancreatic duct epithelial cells.ResultsForkhead box protein M1 and Snail were strongly expressed in HPAC and PANC-1. Epithelial-to-mesenchymal transition-modulated claudin-1 level was lower in PANC-1 than in HPAC. In both cell lines in low-glucose medium, FOXM1 and Snail were decreased and claudin-1 was increased. Knockdown of FOXM1 increased claudin-1 and decreased Snail in both cell lines. Low-glucose medium and downregulation of FOXM1 inhibited the cell migration in both cell lines. In both cell lines, mitochondrial respiration was at higher levels in low-glucose medium than in high-glucose medium. Downregulation of FOXM1 induced mitochondrial respiration in high-glucose medium. In normal human pancreatic duct epithelial cells, FOXM1 and Snail were low and claudin-1 was highly expressed, whereas overexpression of FOXM1 decreased claudin-1.ConclusionsGlucose-dependent FOXM1 promoted EMT via Snail and pancreatic cancer metabolism.

Localization of Tricellular Tight Junction Molecule LSR at Midbody and Centrosome During Cytokinesis in Human Epithelial Cells.

Takumi Konno, Takayuki Kohno, Shin Kikuchi, Hiroshi Shimada, Seiro Satohisa, Kenichi Takano, Tsuyoshi Saito, Takashi Kojima

The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society 68 ( 1 ) 59 - 72 2020.01 [International journal]

Epithelial integrity and barrier function are maintained during cytokinesis in vertebrate epithelial tissues. The changes in localization and the roles of tricellular tight junction molecule lipolysis-stimulated lipoprotein receptor (LSR) during cytokinesis are not well known, although new tricellular tight junctions form at the flank of the midbody during cytokinesis. In this study, we investigated the changes in localization and the role of LSR at the midbody and centrosome during cytokinesis using human endometrial carcinoma cell line Sawano, comparing the tricellular tight junction molecule tricellulin; bicellular tight junction molecules occludin, claudin-7, zonula occludens-1, and cingulin; and the epithelial polarized related molecules apoptosis-stimulating of p53 protein 2, PAR3, and yes-associated protein. During cytokinesis induced by treatment with taxol, the epithelial barrier was maintained and the tricellular tight junction molecules LSR and tricellulin were concentrated at the flank of the acetylated tubulin-positive midbody and in γ-tubulin-positive centrosomes with the dynein adaptor Hook2, whereas the other molecules were localized there as well. All the molecules disappeared by knockdown using small interfering RNAs. Furthermore, by the knockdown of Hook2, the epithelial barrier was maintained and most of the molecules disappeared from the centrosome. These findings suggest that LSR may play crucial roles not only in barrier function but also in cytokinesis.

Tricellular tight junction protein LSR/angulin-1 contributes to the epithelial barrier and malignancy in human pancreatic cancer cell line.

Takuro Kyuno, Daisuke Kyuno, Takayuki Kohno, Takumi Konno, Shin Kikuchi, Chihiro Arimoto, Hiroshi Yamaguchi, Masafumi Imamura, Yasutoshi Kimura, Masuo Kondoh, Ichiro Takemasa, Takashi Kojima

Histochemistry and cell biology 153 ( 1 ) 5 - 16 2020.01 [Refereed] [International journal]

Lipolysis-stimulated lipoprotein receptor (LSR)/angulin-1 is a crucial molecule of tricellular contacts in the epithelial barrier of normal cells and the malignancy of cancer cells. To investigate whether LSR/angulin-1 affects the epithelial barrier and malignancy in human pancreatic cancer, human pancreatic cancer cell line HPAC was used. Treatment with EGF or TGF-β increased the expression of LSR, but not tricellulin (TRIC), and induced the localization of LSR and TRIC to bicellular tight junctions from tricellular tight junctions. TGF-β receptor type-1 inhibitor EW-7197 prevented changes of the distribution and the barrier function of LSR by TGF-β. Knockdown of LSR increased cell migration, invasion, proliferation and EGF ligand amphiregulin expression and decreased the epithelial barrier. Treatment with amphiregulin induced cell migration and invasion and knockdown of amphiregulin prevented the increases of cell migration, invasion and proliferation caused by knockdown of LSR. Treatment with LSR ligand peptide angubindin-1 decreased the epithelial barrier and the expression of LSR, but not TRIC, and increased cell invasion. Knockdown of TRIC decreased cell migration and the epithelial barrier. In immunohistochemical analysis of human pancreatic cancer tissues, LSR and TRIC were found to be localized at the cell membranes of normal pancreatic ducts and well-differentiated pancreatic ductal adenocarcinomas (PDAC), whereas in poorly differentiated PDAC, LSR was weakly detected in the cytoplasm. Amphiregulin was highly expressed in the cytoplasm of well- and poorly differentiated PDAC. In pancreatic cancer, LSR contributes to the epithelial barrier and malignancy via growth factors and may be a potential targeting molecule in the therapy.

Epithelial barrier dysfunction and cell migration induction via JNK/cofilin/actin by angubindin-1.

Takumi Konno, Takayuki Kohno, Shin Kikuchi, Hiroshi Shimada, Seiro Satohisa, Tsuyoshi Saito, Masuo Kondoh, Takashi Kojima

Tissue barriers 8 ( 1 ) 1695475 - 1695475 2020 [International journal]

Angulin-1/LSR is a tricellular tight junction molecule, that plays an important role in maintaining the epithelial and endothelial barriers. The actin cytoskeleton at tricellular contacts also contributes to the maintenance of the epithelial barrier. Loss of angulin-1/LSR enhances the migration of various cancer cells. Angubindin-1 is a novel binder to angulin-1/LSR and angulin-3. It is a peptide generated from the angulin-1 binding site of Clostridium perfringens iota toxin, which affects the actin cytoskeleton and decreases the epithelial and endothelial barrier functions. However, its regulatory mechanisms are not well understood. To investigate the regulatory mechanisms of the epithelial barrier dysfunction and cell migration induction by angubindin-1, we used human endometrial cancer cell line Sawano, which has high LSR expression and the epithelial barrier function. Angubindin-1 decreased LSR expression and the epithelial barrier function and increased cell migration. It inhibited the recovery of the epithelial barrier function in a Ca-switch model. At tricellular contacts, sinking of the membrane and an increase of actin fibers near the junctions were caused by angubindin-1. It dynamically changed F-actin from lines to dot-like structures at tricellular contacts. Angubindin-1 transiently increased the phosphorylation of cofilin and JNK, which are involved in the regulation of the intracellular actin cytoskeleton. Furthermore, knockdown of JNK and the JNK inhibitor SP600125 prevented the decrease of the epithelial barrier function and the increase of cell migration induced by angubindin-1. These findings suggest that angubindin-1 might reversibly regulate the epithelial barrier and cell migration at tricellular contacts via JNK/cofilin/actin cytoskeleton dynamics.

Role of Tricellular Tight Junction Protein Lipolysis-Stimulated Lipoprotein Receptor (LSR) in Cancer Cells.

Takayuki Kohno, Takumi Konno, Takashi Kojima

International journal of molecular sciences 20 ( 14 ) 2019.07 [International journal]

Maintaining a robust epithelial barrier requires the accumulation of tight junction proteins, LSR/angulin-1 and tricellulin, at the tricellular contacts. Alterations in the localization of these proteins temporarily cause epithelial barrier dysfunction, which is closely associated with not only physiological differentiation but also cancer progression and metastasis. In normal human endometrial tissues, the endometrial cells undergo repeated proliferation and differentiation under physiological conditions. Recent observations have revealed that the localization and expression of LSR/angulin-1 and tricellulin are altered in a menstrual cycle-dependent manner. Moreover, it has been shown that endometrial cancer progression affects these alterations. This review highlights the differences in the localization and expression of tight junction proteins in normal endometrial cells and endometrial cancers and how they cause functional changes in cells.

Rho-kinase and PKCα Inhibition Induces Primary Cilia Elongation and Alters the Behavior of Undifferentiated and Differentiated Temperature-sensitive Mouse Cochlear Cells.

Akito Kakiuchi, Takayuki Kohno, Takuya Kakuki, Yakuto Kaneko, Takumi Konno, Yukino Hosaka, Tomohiro Hata, Shin Kikuchi, Takafumi Ninomiya, Tetsuo Himi, Kenichi Takano, Takashi Kojima

The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society 67 ( 7 ) 523 - 535 2019.07 [International journal]

Primary cilia, regulated via distinct signal transduction pathways, play crucial roles in various cellular behaviors. However, the full regulatory mechanism involved in primary cilia development during cellular differentiation is not fully understood, particularly for the sensory hair cells of the mammalian cochlea. In this study, we investigated the effects of the Rho-kinase inhibitor Y27632 and PKCα inhibitor GF109203X on primary cilia-related cell behavior in undifferentiated and differentiated temperature-sensitive mouse cochlear precursor hair cells (the conditionally immortalized US/VOT-E36 cell line). Our results indicate that treatment with Y27632 or GF109203X induced primary cilia elongation and tubulin acetylation in both differentiated and undifferentiated cells. Concomitant with cilia elongation, Y27632 treatment also increased Hook2 and cyclinD1 expression, while only Hook2 expression was increased after treatment with GF109203X. In the undifferentiated cells, we observed an increase in the number of S and G2/M stage cells and a decrease of G1 cells after treatment with Y27632, while the opposite was observed after treatment with GF109203X. Finally, while both treatments decreased oxidative stress, only treatment with Y27632, not GF109203X, induced cell cycle-dependent cell proliferation and cell migration.

Induction of airway progenitor cells via p63 and KLF11 by Rho-kinase inhibitor Y27632 in hTERT-human nasal epithelial cells.

Yakuto Kaneko, Takumi Konno, Takayuki Kohno, Takuya Kakuki, Ryo Miyata, Tsuyoshi Ohkuni, Akito Kakiuchi, Ryoto Yajima, Kizuku Ohwada, Makoto Kurose, Tetsuo Himi, Kenichi Takano, Takashi Kojima

American journal of translational research 11 ( 2 ) 599 - 611 2019 [International journal]

Rho-kinase inhibitor Y27632, which is a factor in conditional reprogramming culture, induces airway progenitor clone formation. To investigate whether Y27632 enhances airway progenitor cells in nasal epithelium, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were treated with Y27632. In TERT-HNECs treated with Y27632 for 5 days, upregulation of p63, gap junction molecules Cx26, Cx30, Cx43, cytochrome P450 enzymes CYP2C9, CYP2C18, CYP39A1, CYP4B1, CYP2G1P, CYP4Z1, and KLF families KLF10 and KLF11 were observed compared to the control. Downregulation of tight junction molecules claudin-4, -7, and -23 was observed. Circumfential submembrane F-actin was also induced. The functions of gap junctional intercellular communication (GJIC) and the epithelial barrier were upregulated. Knockdown of p63 by siRNAs of TAp63 or ΔNp63 inhibited Cx26, Cx43 and CYP2C18, and induced claudin-1, and -4. Knockdown of KLF11 prevented p63 expression and enhancement of the epithelial barrier function by Y27632. In nasal mucosal tissues from patients with allergic rhinitis (AR), localized alteration of p63, KLF11, RhoA, Cx30 and claudin-4 was observed. Treatment with Y27632 in long-term culture induced airway progenitor cells via KLF11 in p63-positive human nasal epithelium. Airway progenitor cells of nasal epithelium induced by Y27632 is important in understanding upper airway disease-specific characteristics.

Mechanism of fibrogenesis in submandibular glands in patients with IgG4-RD.

Ryoto Yajima, Kenichi Takano, Takumi Konno, Takayuki Kohno, Yakuto Kaneko, Takuya Kakuki, Kazuaki Nomura, Akito Kakiuchi, Tetsuo Himi, Takashi Kojima

Journal of molecular histology 49 ( 6 ) 577 - 587 2018.12 [International journal]

The aim of this study was to investigate the mechanisms driving fibrosis in the submandibular glands (SMG) of patients with IgG4-related disease (IgG4-RD). Immunohistochemistry showed that many fibroblast-like cells expressing IL-6, IL-18, TSLP, IL-33, and MMP1 were present in SMG from the affected patients. SMG fibroblasts were derived from patients with or without IgG4-RD and were cultured in vitro. Expression of IL-6, IL-18, TSLP, IL-33 and MMP1, the secretion of IL-6 and G2/M phase were upregulated in the fibroblasts from the affected patients. By treatment with inflammatory cytokines IL-1β, TNFα or TGF-β after treatment with or without the NF-κB inhibitor curcumin, curucumin blocked the production and secretion of IL-6 upregulated by IL-1β, TNFα, or TNFα/TGF-β in all fibroblasts. Wnt1-inducible signaling protein 1 (WISP1), which can enhance fibroblasts proliferation, was also more abundantly expressed in affected fibroblasts, while treatment with IL-6 induced WISP1, treatment with WISP1 increased the G2/M phase, and curucumin inhibited WISP1 induced by TNFα/TGF-β in unaffected fibroblasts. IL-33 in affected fibroblasts was induced by IL-1β, TNFα, or TNFα/TGF-β, while the effect of IL-1β or TNFα/TGF-β was blocked by curcumin. These results suggest fibrosis in the SMG of affected patients is closely linked to the proliferation of fibroblasts following induction of IL-6 and WISP1 by inflammatory cytokines. The Th2 cytokines TSLP and IL-33 are also upregulated in affected SMG, and thus may cause chronic inflammation and IgG4 accumulation.

The role of claudin-2 on the malignancy of human endometrioid carcinoma tissues

Satohisa Seiro, Shimada Hiroshi, Kohno Takayuki, Konno Takumi, Tamate Masato, Matsuura Motoki, Teramoto Mizue, Akimoto Taishi, Iwasaki Masahiro, Kojima Takashi, Saito Tsuyoshi

INTERNATIONAL JOURNAL OF GYNECOLOGICAL CANCER ( BMJ PUBLISHING GROUP ) 28 109 - 109 2018.10 [Refereed]

Occludin induces microvillus formation via phosphorylation of ezrin in a mouse hepatic cell line.

Masaki Murata, Makoto Osanai, Akira Takasawa, Kumi Takasawa, Tomoyuki Aoyama, Yuka Kawada, Akihiro Yamamoto, Yusuke Ono, Yutaro Hiratsuka, Takashi Kojima, Norimasa Sawada

Experimental cell research 366 ( 2 ) 172 - 180 2018.05 [International journal]

Apical and basolateral cell membranes are separated by tight junctions (TJs). Microvilli are limited to the apical cell membrane. TJs and microvilli are the landmarks for epithelial cell polarity. However, the direct relationship between TJ proteins (TJPs) and the components of microvilli remains unclear. In this study, we investigated whether occludin, which is considered to be a functional TJP, is involved in microvillus formation. In occludin knockout mouse hepatic cells (OcKO cells), the microvillus density was less than that in wild-type (WT) cells and the length of microvilli was short. Immunoreactivity of ezrin was decreased in OcKO cells compared with that in WT cells. Although there was no change in the expression level of ezrin, phosphorylation of ezrin was decreased in OcKO cells. The microvillus density and the length of microvilli were increased in OcKO cells by transfection of full-length mouse occludin and COOH-terminal domains of occludin. These results suggested that occludin induced microvillus formation via phosphorylation of ezrin and that the COOH-terminal domain of occludin, which is localized in non-TJ areas, might be able to induce microvilli formation. Our results provide new insights into the function of occludin.

Cobalt inhibits motility of axonal mitochondria and induces axonal degeneration in cultured dorsal root ganglion cells of rat.

Shin Kikuchi, Takafumi Ninomiya, Takayuki Kohno, Takashi Kojima, Haruyuki Tatsumi

Cell biology and toxicology 34 ( 2 ) 93 - 107 2018.04 [International journal]

Cobalt is a trace element that localizes in the human body as cobalamin, also known as vitamin B12. Excessive cobalt exposure induces a peripheral neuropathy, the mechanisms of which are yet to be elucidated. We investigated how cobalt may affect mitochondrial motility in primary cultures of rat dorsal root ganglion (DRG). We observed mitochondrial motility by time-lapse imaging after DsRed2 tagging via lentivirus, mitochondrial structure using transmission electron microscopy (TEM), and axonal swelling using immunocytochemical staining. The concentration of cobaltous ion (Co2+) required to significantly suppress mitochondrial motility is lower than that required to induce axonal swelling following a 24-h treatment. Exposure to relatively low concentrations of Co2+ for 48 h suppressed mitochondrial motility without leading to axonal swelling. TEM images indicated that Co2+ induces mitochondrial destruction. Our results show that destruction of the axonal mitochondria precedes the axonal degeneration induced by Co2+ exposure.

The role of transcriptional factors FOXM1/KLF4 in glucose metabolism during EMT of pancreatic cancer

Kyuno, Takuro, Kojima, Takashi, Konno, Takumi, Kohno, Takayuki, Yamaguchi, Hiroshi, Imamura, Masafumi, Kimura, Yasutoshi, Takemasa, Ichiro

Cancer Science 2018

Guanylate binding protein-1-mediated epithelial barrier in human salivary gland duct epithelium.

Konno T, Takano K, Kaneko Y, Kakuki T, Nomura K, Yajima R, Kakiuchi A, Kohno T, Himi T, Kojima T

Exp Cell Res. 371(1):31-41 2018 [Refereed]

LOSS OF ASPP2 PROMOTES CELL INVASION AND MIGRATION VIA YAP IN HUMAN ENDOMETRIAL CANCER

Shimada, H, Satohisa, S, Konno, T, Matsuura, M, Teramoto, M, Kohno, T, Iwasaki, M, Kojima, T, Saito, T

International Journal of Gynecological Cancer 2018

Downregulation of lipolysis-stimulated lipoprotein receptor promotes cell invasion via claudin-1-mediated matrix metalloproteinases in human endometrial cancer.

Hiroshi Shimada, Seiro Satohisa, Takayuki Kohno, Takumi Konno, Ken-Ichi Takano, Syunta Takahashi, Tsubasa Hatakeyama, Chihiro Arimoto, Tsuyoshi Saito, Takashi Kojima

Oncology letters 14 ( 6 ) 6776 - 6782 2017.12 [International journal]

Lipolysis-stimulated lipoprotein receptor (LSR) is a novel molecule present at tricellular contacts which recruits tricellulin (TRIC), a molecular component of tricellular tight junctions (tTJs). LSR and TRIC are colocalized with the bicellular tight junction (bTJ) protein claudin (CLDN)-1-based tight junction strands at tricellular corners. Knockdown of LSR in normal epithelial cells affects tTJ formation and the epithelial barrier function. In cancer cells knockdown of LSR has been demonstrated to increase cell invasion. However, the detailed mechanisms of how the downregulation of LSR enhances cell invasion in cancer remain unclear. In the present study, knockdown of LSR by small interfering RNA (siRNA) in Sawano human endometrial adenocarcinoma cells induced cell invasion. In LSR-knockdown Sawano cells, upregulation of CLDN-1 protein, which contributes to the cell invasion via matrix metalloproteinases (MMPs), was observed compared with the control group by western blotting and immunostaining. Knockdown of LSR significantly induced Sp1 transcription factor activity in the CLDN-1 promoter region. In LSR-knockdown Sawano cells, DNA microarray analysis demonstrated that MMP-1, MMP-2 and MMP-10 mRNA levels were increased, and the protein levels of membrane-type 1-MMP, MMP-2, MMP-9 and MMP-10 were shown to be increased on western blots. Knockdown of CLDN-1 with siRNA prevented the upregulation of cell invasion induced by the knockdown of LSR in Sawano cells. On the invasive front of human endometrial carcinoma tissue samples, a decrease in LSR and increase in CLDN-1 protein levels were observed using immunohistochemical methods. In conclusion, the results indicate that the downregulation of LSR promotes cell invasion of human endometrial cancer via CLDN-1 mediation of MMPs. This mechanism is important for studying the association of tTJs with the cellular invasion of cancer.

Regulation of claudin-4 via p63 in human epithelial cells

Takashi Kojima, Takayuki Kohno, Terufumi Kubo, Yakuto Kaneko, Takuya Kakuki, Akito Kakiuchi, Makoto Kurose, Ken-ichi Takano, Noriko Ogasawara, Kazufumi Obata, Kazuaki Nomura, Ryo Miyata, Takumi Konno, Shingo Ichimiya, Tetsuo Himi

ANNALS OF THE NEW YORK ACADEMY OF SCIENCES ( WILEY ) 1405 ( 1 ) 25 - 31 2017.10 [Refereed]

P63 is a regulator of cell-cell junction complexes in the epidermis. Claudin-4 is regulated via various factors in normal epithelial cells and diseases. We found that claudin-4 was directly regulated via p63 (TAp63 and Delta Np63) in human keratinocytes and nasal epithelial cells. In the epidermis of atopic dermatitis (AD), which contains Delta Np63-deficient keratinocytes, high expression of claudin-4 was observed. In primary keratinocytes, downregulation of Delta Np63 by treatment with short interfering RNA (siRNA)-p63 induced claudin-4 expression. In nasal epithelial cells in the context of rhinitis or nasal polyps, upregulation of TAp63 and downregulation of claudin-4 were observed. In primary nasal epithelial cells transfected with the human telomerase reverse transcriptase gene, knockdown of p63 by siRNAs induced claudin-4 expression. Taken together, these findings indicate that p63 is a negative regulator of claudin-4 expression. Understanding the regulation of claudin-4 via p63 in human epithelial cells may be important for developing therapies for allergies and drug delivery systems.

The role of transcriptional factor p63 in regulation of epithelial barrier and ciliogenesis of human nasal epithelial cells

Yakuto Kaneko, Takayuki Kohno, Takuya Kakuki, Ken-ichi Takano, Noriko Ogasawara, Ryo Miyata, Shin Kikuchi, Takumi Konno, Tsuyoshi Ohkuni, Ryoto Yajima, Akito Kakiuchi, Shin-ichi Yokota, Tetsuo Himi, Takashi Kojima

SCIENTIFIC REPORTS ( NATURE PUBLISHING GROUP ) 7 2017.09 [Refereed]

Disruption of nasal epithelial tight junctions (TJs) and ciliary dysfunction are found in patients with chronic rhinosinusitis (CRS) and nasal polyps (NPs), along with an increase of p63-positive basal cells and histone deacetylase (HDAC) activity. To investigate these mechanisms, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were transfected with siRNAs of TAp63 and Delta Np63, treated with the NF-kB inhibitor curucumin and inhibitors of HDACs, and infected with respiratory syncytial virus (RSV). In TERT-HNECs, knockdown of p63 by siRNAs of TAp63 and Delta Np63, induced claudin-1 and -4 with Sp1 activity and enhanced barrier and fence functions. The knockdown of p63 enhanced the number of microvilli with the presence of cilia-like structures. Treatment with curcumin and inhibitors of HDACs, or infection with RSV prevented expression of p63 with an increase of claudin-4 and the number of microvilli. The knockdown or downregulation of p63 inhibited phospho-p38MAPK, and the p38MAPK inhibitor downregulated p63 and upregulated the barrier function. Thus, epithelial barrier and ciliogenesis of nasal epithelium are regulated in a p63-negative manner in normal and upper airway diseases. Understanding of the regulation of p63/p38 MAPK/NF-kappa B may be important in the therapy for airway allergy and its drug delivery system.

The bicellular tensile force sorts the localization of LSRs in bicellular and tricellular junctions.

Takayuki Kohno, Shin Kikuchi, Takafumi Ninomiya, Takashi Kojima

Annals of the New York Academy of Sciences 1397 ( 1 ) 185 - 194 2017.06 [International journal]

Lipolysis-stimulated lipoprotein receptors (LSRs) localize to tricellular tight junctions. Recent studies have shown that changes in the localization and expression profiles of LSRs are associated with malignancy of endometrial carcinomas, although the precise mechanisms by which malignant progression induces changes in the localization of LSRs are still unknown. In this study, we found that changes in cell tension correlated with alterations in the junctional localization of LSRs in endometrial cancer Sawano cells. At high cell densities, myosin phosphatase target subunit 1 (MYPT1) localized to bicellular junctions, whereas activated myosin regulatory light chain 2 (MRLC2) was dislocated from these regions, suggesting that circumferential tensile forces decreased at high cell densities. Under these conditions, LSRs localized to tricellular junctions. In contrast, a phosphorylated form of MRLC2 localized to bicellular regions, while MYPT1 was excluded from these regions, suggesting that tensile forces formed along the circumferential edge at low cell densities. It is noteworthy that, when cells were cultured under these conditions, LSRs localized to bicellular regions. Upon treatment with a myosin inhibitor, LSR localization in bicellular junctions decreased at low cell densities. Overall, our results indicate that the modulation of cellular tension was involved in the translocation of LSRs from bicellular to tricellular tight junctions.

細胞密度に依存的なLSRの膜での局在変化はミオシン活性と相関する

幸野貴之, 嶋田浩志, 金野匠, 小島隆

日本病理学会会誌 ( (一社)日本病理学会 ) 106 ( 1 ) 356 - 356 2017.03

Loss of tricellular tight junction protein LSR promotes cell invasion and migration via upregulation of TEAD1/AREG in human endometrial cancer

Hiroshi Shimada, Shyuetsu Abe, Takayuki Kohno, Seiro Satohisa, Takumi Konno, Syunta Takahashi, Tsubasa Hatakeyama, Chihiro Arimoto, Takuya Kakuki, Yakuto Kaneko, Ken-ichi Takano, Tsuyoshi Saito, Takashi Kojima

SCIENTIFIC REPORTS ( NATURE PUBLISHING GROUP ) 7 2017.01 [Refereed]

Lipolysis-stimulated lipoprotein receptor (LSR) is a unique molecule of tricellular contacts of normal and cancer cells. We investigated how the loss of LSR induced cell migration, invasion and proliferation in endometrial cancer cell line Sawano. mRNAs of amphiregulin (AREG) and TEA domain family member 1 (TEAD1) were markedly upregulated by siRNA-LSR. In endometrial cancer tissues, downregulation of LSR and upregulation of AREG were observed together with malignancy, and Yes-associated protein (YAP) was present in the nuclei. siRNA-AREG prevented the cell migration and invasion induced by siRNA-LSR, whereas treatment with AREG induced cell migration and invasion. LSR was colocalized with TRIC, angiomotin (AMOT), Merlin and phosphorylated YAP (pYAP). siRNA-LSR increased expression of pYAP and decreased that of AMOT and Merlin. siRNA-YAP prevented expression of the mRNAs of AREG and TEAD1, and the cell migration and invasion induced by siRNA-LSR. Treatment with dobutamine and 2-deoxy-D-glucose and glucose starvation induced the pYAP expression and prevented the cell migration and invasion induced by siRNA-LSR. siRNA-AMOT decreased the Merlin expression and prevented the cell migration and invasion induced by siRNA-LSR. The loss of LSR promoted cell invasion and migration via upregulation of TEAD1/AREG dependent on YAP/pYAP and AMOT/Merlin in human endometrial cancer cells.

Histone deacetylase inhibition prevents cell death induced by loss of tricellular tight junction proteins in temperature-sensitive mouse cochlear cells.

Kenichi Takano, Takuya Kakuki, Yakuto Kaneko, Takayuki Kohno, Shin Kikuchi, Tetsuo Himi, Takashi Kojima

PloS one 12 ( 8 ) e0182291 2017 [International journal]

Tricellular tight junctions (tTJs) are specialized structures that occur where the corners of three cells meet to seal adjacent intercellular space. The molecular components of tTJs include tricellulin (TRIC) and lipolysis-stimulated lipoprotein receptor (LSR) which recruits TRIC, are required for normal hearing. Although loss of TRIC causes hearing loss with degeneration of cochlear cells, the detailed mechanisms remains unclear. In the present study, by using temperature-sensitive mouse cochlear cells, US/VOT-E36 cell line, we investigated the changes of TRIC and LSR during cochlear cell differentiation and the effects of histone deacetylase (HDAC) inhibitors against cell degeneration induced by loss of TRIC and LSR. During cell differentiation induced by the temperature change, expression of TRIC and LSR were clearly induced. Treatment with metformin enhanced expression TRIC and LSR via AMPK during cell differentiation. Loss of TRIC and LSR by the siRNAs induced cell death in differentiated cells. Treatment with HDAC inhibitors trichostatin A and HDAC6 inhibitor prevented the cell death induced by loss of TRIC and LSR. Collectively, these findings suggest that both tTJ proteins TRIC and LSR have crucial roles for the differentiated cochlear cell survival, and that HDAC inhibitors may be potential therapeutic agents to prevent hearing loss.

Clarithromycin prevents human respiratory syncytial virus-induced airway epithelial responses by modulating activation of interferon regulatory factor-3

Keisuke Yamamoto, Soh Yamamoto, Noriko Ogasawara, Kenichi Takano, Tsukasa Shiraishi, Toyotaka Sato, Ryo Miyata, Takuya Kakuki, Ryuta Kamekura, Takashi Kojima, Hiroyuki Tsutsumi, Tetsuo Himi, Shin-ichi Yokota

PHARMACOLOGICAL RESEARCH ( ACADEMIC PRESS LTD- ELSEVIER SCIENCE LTD ) 111 804 - 814 2016.09 [Refereed]

Macrolide antibiotics exert immunomodulatory activity by reducing pro-inflammatory cytokine production by airway epithelial cells, fibroblasts, vascular endothelial cells, and immune cells. However, the underlying mechanism of action remains unclear. Here, we examined the effect of clarithromycin (CAM) on pro-inflammatory cytokine production, including interferons (IFNs), by primary human nasal epithelial cells and lung epithelial cell lines (A549 and BEAS-2B cells) after stimulation by Toll-like receptor (TLR) and RIG-I-like receptor (RLR) agonists and after infection by human respiratory syncytial virus (RSV). CAM treatment led to a significant reduction in poly I:C-and RSV-mediated IL-8, CCL5, IFN-beta and -lambda production. Furthermore, IFN-beta promoter activity (activated by poly I:C and RSV infection) was significantly reduced after treatment with CAM. CAM also inhibited IRF-3 dimerization and subsequent translocation to the nucleus. We conclude that CAM acts a crucial modulator of the innate immune response, particularly IFN production, by modulating IRF-3 dimerization and subsequent translocation to the nucleus of airway epithelial cells. This newly identified immunomodulatory action of CAM will facilitate the discovery of new macrolides with an anti-inflammatory role. (C) 2016 Elsevier Ltd. All rights reserved.

Dysregulation of junctional adhesion molecule-A via p63/GATA-3 in head and neck squamous cell carcinoma

Takuya Kakuki, Makoto Kurose, Ken-ichi Takano, Atsushi Kondoh, Kazufumi Obata, Kazuaki Nomura, Ryo Miyata, Yakuto Kaneko, Takumi Konno, Syunta Takahashi, Tsubasa Hatakeyama, Takayuki Kohno, Tetsuo Himi, Takashi Kojima

ONCOTARGET ( IMPACT JOURNALS LLC ) 7 ( 23 ) 33887 - 33900 2016.06 [Refereed]

Junctional adhesion molecule-A (JAM-A), which belongs to the IgG superfamily, is a tight junction molecule associated with epithelial and endothelial barrier function. Overexpression of JAM-A is also closely associated with invasion and metastasis of cancers such as breast cancer, lung cancer and pancreatic cancer. However, little is known about the mechanism in overexpression of JAM-A in head and neck squamous cell carcinoma (HNSCC). In the present study, we found high expression of JAM-A at the protein and mRNA levels in HNSCC tissues, including those of the oropahrynx, larynx, and hypopharynx, together with high protein expression of beta-catenin, p63, Delta Np63 and GATA-3. Furthermore, in ELISA, a significant increase of soluble JAM-A in the sera of HNSCC patients was observed compared to healthy subjects. Knockdown of JAM-A by siRNA inhibited cell proliferation, invasion and migration in the HNSCC cell line Detroit562 in vitro. JAM-A expression in Detroit562 was increased via a distinct signal transduction pathway including NF-kappa B. Expression of JAM-A, beta-catenin, p63 and Delta Np63 in Detroit562 was decreased under hypoxia. Knockdown of p63, Delta Np63 or GATA-3 by siRNAs reduced JAM-A expression in Detroit562. In primary cultured HNSCC cells in which CK7, p63, Delta Np63 and GATA-3 were detected, JAM-A expression was decreased by knockdown of p63 or Delta Np63. These results indicate that JAM-A is a biomarker of malignancy in HNSCC and that plasma soluble JAM-A may contribute to serum-based diagnosis of HNSCC. The mechanism of dysregulation of JAM-A via p63/GATA-3 is important in possible molecular targeted therapy for HNSCC.

The roles of tricellular tight junction protein lipolysis-stimulated lipoprotein receptor in malignancy of human endometrial cancer cells

Hiroshi Shimada, Seiro Satohisa, Takayuki Kohno, Syunta Takahashi, Tsubasa Hatakeyama, Takumi Konno, Mitsuhiro Tsujiwaki, Tsuyoshi Saito, Takashi Kojima

ONCOTARGET ( IMPACT JOURNALS LLC ) 7 ( 19 ) 27735 - 27752 2016.05 [Refereed]

Lipolysis-stimulated lipoprotein receptor (LSR) has been identified as a novel molecular constituent of tricellular contacts that have a barrier function for the cellular sheet. LSR recruits tricellulin (TRIC), which is the first molecular component of tricellular tight junctions. Knockdown of LSR increases cell motility and invasion of certain cancer cells. However, the behavior and the roles of LSR in endometrial cancer remain unknown. In the present study, we investigated the behavior and roles of LSR in normal and endometrial cancer cells in vivo and in vitro. In endometriosis and endometrial cancer, LSR was observed not only in the subapical region but also throughout the lateral region as well as in normal endometrial epithelial cells in the secretory phase, and LSR in the cancer was reduced in correlation with the malignancy. Knockdown of LSR by the siRNA in cells of the endometrial cancer cell line Sawano, induced cell migration, invasion and proliferation, while TRIC relocalized from the tricellular region to the bicellular region at the membrane. In Sawano cells and normal HEEs, a decrease of LSR induced by leptin and an increase of LSR induced by adiponectin and the drugs for type 2 diabetes metformin and berberine were observed via distinct signaling pathways including JAK2/STAT. In Sawano cells, metformin and berberine prevented cell migration and invasion induced by downregulation of LSR by the siRNA and leptin treatment. The dissection of the mechanism in the downregulation of endometrial LSR during obesity is important in developing new diagnostic and therapy for endometrial cancer.

Junctional adhesion molecule - A in head and neck squamous cell carcinoma

Makoto Kurose, Takuya Kakuki, Kenichi Takano, Atsushi Kondo, Kazufumi Obata, Kazuaki Nomura, Ryo Miyata, Yakuto Kaneko, Takumi Konno, Takayuki Kohno, Takashi Kojima, Tetsuo Himi

Advances in Oto-Rhino-Laryngology ( S. Karger AG ) 77 92 - 97 2016 [Refereed]

Junctional adhesion molecule-A (JAM-A), which belongs to the IgG superfamily, is one of the tight junction molecules. JAM-A is dysregulated in various cancers and is closely associated with the invasion and metastasis of cancers such as breast cancer, lung cancer and pancreatic cancer. In the present study, we found a high expression of JAM-A in head and neck squamous cell carcinoma (HNSCC) as well as β-catenin in immunohistochemistry. The expression of JAM-A and β-catenin was of a low level in differentiation-induced cancer pearl regions of HNSCC. Real-time PCR showed the high expression of JAM-A mRNA through all differentiated stages (well, moderate, poor) of HNSCC. When we performed ELISA using the serum of HNSCC patients to measure plasma-soluble JAM-A, it was found to be higher in HNSCC patients than healthy subjects. These results indicate that JAM-A is one of the malignancy markers of HNSCC as well as β-catenin in histopathology, and the plasma-soluble JAM-A may contribute to a serum diagnosis of HNSCC. JAM-A is a promising molecular target for diagnosis and therapy in HNSCC.

Behavior of Primary Cilia and Tricellular Tight Junction Proteins during Differentiation in Temperature-Sensitive Mouse Cochlear Precursor Hair Cells.

Kakuki T, Kaneko Y, Takano K, Ninomiya T, Kohno T, Kojima T, Himi T

Adv. Otorhinolaryngol. 77:27-32. 2016 [Refereed]

The behavior and role of lipolysis-stimulated lipoprotein receptor, a component of tricellular tight junctions, in head and neck squamous cell carcinomas.

Takano K, Kakuki T, Obata K, Nomura K, Miyata R, Kondo A, Kurose M, Kakiuch A, Kaneko Y, Kohno T, Himi T, Kojima T

Anticancer Research 36(11):5895-5904. 2016 [Refereed]

Claudin-4 binder C-CPE 194 enhances effects of anticancer agents on pancreatic cancer cell lines via a MAPK pathway.

Tsuyoshi Kono, Masuo Kondoh, Daisuke Kyuno, Tatsuya Ito, Yasutoshi Kimura, Masafumi Imamura, Takayuki Kohno, Takumi Konno, Tomohisa Furuhata, Norimasa Sawada, Koichi Hirata, Takashi Kojima

Pharmacology research & perspectives 3 ( 6 ) e00196 2015.12 [Refereed] [International journal]

The C-terminal fragment of Clostridium perfringens enterotoxin (C-CPE) modulates the tight junction protein claudin and disrupts the tight junctional barrier. It also can enhance the effectiveness of anticancer agents. However, the detailed mechanisms of the effects of C-CPE remain unclear in both normal and cancerous cells. The C-CPE mutant called C-CPE 194 binds only to claudin-4, but the C-CPE 194 mutant called C-CPE m19 binds not only to claudin-4 but also to claudin-1. In the present study, to investigate the mechanisms of the effects of C-CPE on claudin expression, the tight junctional functions and the cytotoxicity of anticancer agents, human pancreatic cancer cells, and normal human pancreatic duct epithelial cells (HPDEs) were treated with C-CPE 194 and C-CPE m19. In well-differentiated cells of the pancreatic cancer cell line HPAC, C-CPE 194 and C-CPE m19 disrupted both the barrier and fence functions without changes in expression of claudin-1 and -4, together with an increase of MAPK phosphorylation. C-CPE 194, but not C-CPE m19, enhanced the cytotoxicity of the anticancer agents gemcitabine and S-1. In poorly differentiated pancreatic cancer cell line PANC-1, C-CPE 194, but not C-CPE m19, decreased claudin-4 expression and enhanced MAPK activity and the cytotoxicity of the anticancer agents. In normal HPDEs, C-CPE 194 and C-CPE m19 decreased claudin-4 expression and enhanced the MAPK activity, whereas they did not affect the cytotoxicity of the anticancer agents. Our findings suggest that the claudin-4 binder C-CPE 194 enhances effects of anticancer agents on pancreatic cancer cell lines via a MAPK pathway.

肥満によるヒト子宮内膜癌の悪性化におけるlipolysis-stimulated lipoprotein receptorの役割

小島隆, 嶋田浩志, 郷久晴朗, 金野匠, 高橋俊太, 畠山翔翼, 有元千尋, 野島伊世里, 齋藤豪, 幸野貴之

日本生化学会大会・日本分子生物学会年会合同大会講演要旨集 ( (公社)日本生化学会 ) 88回・38回 [3T18p - 01(3P1048)] 2015.12

Poly(I:C) induced microRNA-146a regulates epithelial barrier and secretion of proinflammatory cytokines in human nasal epithelial cells

Ryo Miyata, Takuya Kakuki, Kazuaki Nomura, Tsuyoshi Ohkuni, Noriko Ogasawara, Ken-ichi Takano, Takumi Konno, Takayuki Kohno, Norimasa Sawada, Tetsuo Himi, Takashi Kojima

EUROPEAN JOURNAL OF PHARMACOLOGY ( ELSEVIER SCIENCE BV ) 761 375 - 382 2015.08 [Refereed]

Human nasal epithelial cells (HNECs) are important in the tight junctional barrier and innate immune defense protecting against pathogens invading via Toll-like receptors (TERs). MicroRNAs (miRNAs) I egulate expression of tight junctions as direct or indirect targeting genes and maintain the barrier Function. However, the roles of miRNAs in the epithelial barrier of HNECs via TLRs remain unknown. In the present study, to investigate the effects of miRNAs on the epithelial barrier of HNECs via TLRs, primary cultured HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs), were treated with the TLR3 ligand poly(I:C) and miRNA array analysis was performed. In the miRNA array of the cells treated with poly(I:C), upregulation of miR-187, -146a, -574, -4274, -4433, -4455 and -4750, and downregulation of miR-4785 by more than twofold compared to the control were observed. When control HNECs were treated with mimics and inhibitors of these miRNAs, an miR-146a mimic induced expression of tight junction proteins claudin-1, occludin and JAM-A together with an increase of the epithelial barrier function. The poly(I:C)-induced miR-146a was regulated via the distinct TLR3-mediatecl signal pathways PI3K, JNK and NE-kappa B. Furthermore, the miR-146a mimic prevented downregulation of claudin-1 and JAM-A and the secretion of proinflammatory cytokines IL-8 and TNF-alpha induced by poly (I:C) by targeting TRAFG. These findings indicate that, in HNECs, miRNA-146a plays crucial roles in maintenance of the tight junction barrier and innate immune defense protecting against invading pathogens. (C) 2015 Elsevier B.V. All rights reserved.

Staurosporine Induces Formation of Two Types of Extra-Long Cell Protrusions: Actin-Based Filaments and Microtubule-Based Shafts

Takayuki Kohno, Takafumi Ninomiya, Shin Kikuchi, Takumi Konno, Takashi Kojima

MOLECULAR PHARMACOLOGY ( AMER SOC PHARMACOLOGY EXPERIMENTAL THERAPEUTICS ) 87 ( 5 ) 815 - 824 2015.05 [Refereed]

Staurosporine (STS) has been known as a classic protein kinase C inhibitor and is a broad-spectrum inhibitor targeting over 250 protein kinases. In this study, we observed that STS treatment induced drastic morphologic changes, such as elongation of a very large number of nonbranched, actin-based long cell protrusions that reached up to 30 mu m in an hour without caspase activation or PARP cleavage in fibroblasts and epithelial cells. These cell protrusions were elongated not only from the free cell edge but also from the cell-cell junctions. The elongation of STS-dependent protrusions was required for ATP hydrolysis and was dependent on myosin-X and fascin but independent of Cdc42 and VASP. Interestingly, in the presence of an actin polymerization inhibitor, namely, cytochalasin D, latrunculin A, or jasplakinolide, STS treatment induced excess tubulin polymerization, which resulted in the formation of many extra-long microtubule (MT)-based protrusions toward the outside of the cell. The unique MT-based protrusions were thick and linear compared with the STS-induced filaments or stationary filopodia. These protrusions, which were composed of microtubules, have been scarcely observed in cultured non-neuronal cells. Taken together, our findings revealed that STS-sensitive kinases are essential for the maintenance of normal cell morphology, and a common unidentified molecular mechanism is involved in the formation of the following two different types of protrusions: actin-based filaments and MT-based shafts.

Irsogladine maleate regulates gap junctional intercellular communication-dependent epithelial barrier in human nasal epithelial cells.

Miyata R, Nomura K, Kakuki T, Takano K, Kohno T, Konno T, Sawada N, Himi T, Kojima T

The Journal of membrane biology ( 2 ) 248 327 - 336 2015.04 [Refereed]

Aberrant expression of claudin-4 and -7 in hepatocytes in the cirrhotic human liver

Tsujiwaki M, Murata M, Takasawa A, Hiratsuka Y, Fukuda R, Sugimoto K, Ono Y, Nojima M, Tanaka S, Hirata K, Kojima T, Sawada N

Med Mol Morphol 48 ( 1 ) 33 - 43 2015.03 [Refereed]

扁桃・アデノイドはなぜあるのか?鼻はなにをしているのか? 粘膜免疫・粘膜防御の最前線を探る

氷見徹夫, 高野賢一, 山下恵司, 小笠原徳子, 山本圭佑, 堤裕幸, 小島隆, 一宮慎吾, 澤田典均, 横田伸一

顎顔面口腔育成会誌 ( 顎顔面口腔育成研究会 ) 3 ( 1 ) 3 - 6 2015.03

粘膜防御機構は自然免疫の最前線であり、上皮細胞に加えて免疫系細胞などを含む複合的なシステムで構築されている。耳鼻咽喉科領域では扁桃・アデノイドに代表される粘膜関連リンパ装置は、その抗原捕捉機構を駆使して、免疫記憶の形成と特異的抗体産生機構に関与している。一方、上気道の最前線である鼻粘膜もまた抗原捕捉に伴う免疫反応を行っているとともに、ウイルス・細菌感染やアレルギー炎症の場としても重要である。われわれは、扁桃やアデノイド、そして鼻粘膜の上皮についての研究を行い、機械的バリアを含む自然免疫の新しい概念を提唱してきた。ここでは、われわれの研究より得られた知見をもとに、扁桃、鼻粘膜の基本的な免疫臓器としての機能解析と、それぞれの類似性・相違性、自然免疫・獲得免疫での位置づけについて言及する。(著者抄録)

Claudin-binder C-CPE mutants enhance permeability of insulin across human nasal epithelial cells.

Kojima T, Kondoh M, Keira T, Takano KI, Kakuki T, Kaneko Y, Miyata R, Nomura K, Obata K, Kohno T, Konno T, Sawada N, Himi T

Drug Deliv. 23(8):2703-2710 2015 [Refereed]

c-Jun N-terminal kinase inhibitor SP600125 enhances barrier function and elongation of human pancreatic cancer cell line HPAC in a Ca-switch model.

Konno T, Ninomiya T, Kohno T, Kikuchi S, Sawada N, Kojima T

Histochem. Cell Biol. 143(5):471-9. 2015 [Refereed]

Tight junction protein claudin-4 is modulated via ΔNp63 in human keratinocytes.

Kubo T, Sugimoto K, Kojima T, Sawada N, Sato N, Ichimiya S

Biochem Biophys Res Commun 455 ( 3-4 ) 205 - 211 2014.12 [Refereed]

Targeting tight junctions during epithelial to mesenchymal transition in human pancreatic cancer.

Daisuke Kyuno, Hiroshi Yamaguchi, Tatsuya Ito, Tsuyoshi Kono, Yasutoshi Kimura, Masafumi Imamura, Takumi Konno, Koichi Hirata, Norimasa Sawada, Takashi Kojima

World journal of gastroenterology ( 31 ) 20 ( 31 ) 10813 - 24 2014.08 [Refereed] [International journal]

Pancreatic cancer continues to be a leading cause of cancer-related death worldwide and there is an urgent need to develop novel diagnostic and therapeutic strategies to reduce the mortality of patients with this disease. In pancreatic cancer, some tight junction proteins, including claudins, are abnormally regulated and therefore are promising molecular targets for diagnosis, prognosis and therapy. Claudin-4 and -18 are overexpressed in human pancreatic cancer and its precursor lesions. Claudin-4 is a high affinity receptor of Clostridium perfringens enterotoxin (CPE). The cytotoxic effects of CPE and monoclonal antibodies against claudin-4 are useful as novel therapeutic tools for pancreatic cancer. Claudin-18 could be a putative marker and therapeutic target with prognostic implications for patients with pancreatic cancer. Claudin-1, -7, tricellulin and marvelD3 are involved in epithelial to mesenchymal transition (EMT) of pancreatic cancer cells and thus might be useful as biomarkers during disease. Protein kinase C is closely related to EMT of pancreatic cancer and regulates tight junctions of normal human pancreatic duct epithelial cells and the cancer cells. This review focuses on the regulation of tight junctions via protein kinase C during EMT in human pancreatic cancer for the purpose of developing new diagnostic and therapeutic modalities for pancreatic cancer.

Delta Np63 Controls a TLR3-Mediated Mechanism That Abundantly Provides Thymic Stromal Lymphopoietin in Atopic Dermatitis

Terufumi Kubo, Ryuta Kamekura, Ayako Kumagai, Koji Kawata, Keiji Yamashita, Yukari Mitsuhashi, Takashi Kojima, Kotaro Sugimoto, Akihiro Yoneta, Yasuyuki Sumikawa, Toshiharu Yamashita, Noriyuki Sato, Tetsuo Himi, Shingo Ichimiya

PLOS ONE ( PUBLIC LIBRARY SCIENCE ) 9 ( 8 ) e105498 2014.08 [Refereed]

In the skin lesions of atopic dermatitis (AD), keratinocytes release large quantities of thymic stromal lymphopoietin (TSLP), causing unfavorable inflammation along with skin damage. Nevertheless, how TSLP influences keratinocytes themselves is still unknown. In this study, we showed that Delta Np63, a p53-homologue, predominantly expressed in keratinocytes regulated the receptor complex of TSLP, which determines susceptibility to self-derived TSLP. Expression of TSLP receptors in skin tissues and keratinocytes was assessed by immunohistochemistry and quantitative RT-PCR, and in vitro studies were also performed to examine the functional relevance of Delta Np63 in the expression of TSLP receptors and the constituting autocrine and/or paracrine pathway of TSLP under the condition of stimuli to innate receptors sensing cell damage. The results showed that normal keratinocytes in the upper epidermis preferentially expressed TSLP receptors and conversely lacked Delta Np63, which has an inhibitory effect on the expression of TSLP receptors. Interestingly, the epidermis of AD lesions was found to abundantly contain keratinocytes with low or undetectable levels of Delta Np63 (Delta Np63(lo/-)). Moreover, in the absence of Delta Np63, keratinocytes readily presented TSLP and other cytokines by stimuli through Toll-like receptor 3 (TLR3). Together with the evidence that extrinsic TSLP itself augments TSLP production by keratinocytes without Delta Np63, the results indicate that Delta Np63(lo/-) keratinocytes generate TSLP through a putative autocrine and/or paracrine pathway upon TLR3 stimulation within AD lesions, since moieties of damaged cells and pathogens stimulate TLR3.

Pseudomonas aeruginosa elastase causes transient disruption of tight junctions and downregulation of PAR-2 in human nasal epithelial cells

Kazuaki Nomura, Kazufumi Obata, Takashi Keira, Ryo Miyata, Satoshi Hirakawa, Ken-ichi Takano, Takayuki Kohno, Norimasa Sawada, Tetsuo Himi, Takashi Kojima

RESPIRATORY RESEARCH ( BIOMED CENTRAL LTD ) 15 2014.02 [Refereed]

Background: Pseudomonas aeruginosa causes chronic respiratory disease, and the elastase enzyme that it produces increases the permeability of airway epithelial cells owing to the disruption of tight junctions. P. aeruginosa is also implicated in prolonged chronic rhinosinusitis. However, the effects of P. aeruginosa elastase (PE) against the barrier formed by human nasal epithelial cells (HNECs) remain unknown. Methods: To investigate the mechanisms involved in the disruption of tight junctions by PE in HNECs, primary cultures of HNECs transfected with human telomerase reverse transcriptase (hTERT-HNECs) were used. The hTERT-HNECs were pretreated with inhibitors of various signal transduction pathways, PKC, MAPK, p38MAPK, PI3K, JNK, NF-kappa B, EGF receptor, proteasome, COX1 and COX2 before treatment with PE. Some cells were pretreated with siRNA and agonist of protease activated receptor-2 (PAR-2) before treatment with PE. Expression and structures of tight junctions were determined by Western blotting, real-time PCR, immunostaining and freeze-fracture. Transepithelial electrical resistance (TER) was examined as the epithelial barrier function. Results: PE treatment transiently disrupted the epithelial barrier and downregulated the transmembrane proteins claudin-1 and -4, occludin, and tricellulin, but not the scaffold PDZ-expression proteins ZO-1 and -2 and adherens junction proteins E-cadherin and beta-catenin. The transient downregulation of tight junction proteins was controlled via distinct signal transduction pathways such as the PKC, MAPK, PI3K, p38 MAPK, JNK, COX-1 and -2, and NF-kappa B pathways. Furthermore, treatment with PE transiently decreased PAR-2 expression, which also regulated the expression of the tight junction proteins. Treatment with a PAR-2 agonist prevented the downregulation of the tight junction proteins after PE treatment in HNECs. Conclusions: PE transiently disrupts tight junctions in HNECs and downregulates PAR-2. The transient disruption of tight junctions by PE might occur repeatedly during chronic rhinosinusitis.

Changes of Tight Junction Protein Claudins in Small Intestine and Kidney Tissues of Mice Fed a DDC Diet.

Abiko Y, Kojima T, Murata M, Tsujiwaki M, Takeuchi M, Sawada N, Mori M

Journal of toxicologic pathology ( 4 ) 26 433 - 438 2013.12 [Refereed]

Humulone suppresses replication of respiratory syncytial virus and release of IL-8 and RANTES in normal human nasal epithelial cells

Jun Fuchimoto, Takashi Kojima, Tamaki Okabayashi, Tomoyuki Masaki, Noriko Ogasawara, Kazufumi Obata, Kazuaki Nomura, Satoshi Hirakawa, Naoyuki Kobayashi, Tatsuro Shigyo, Shin-ichi Yokota, Nobuhiro Fujii, Hiroyuki Tsutsumi, Tetsuo Himi, Norimasa Sawada

MEDICAL MOLECULAR MORPHOLOGY ( SPRINGER JAPAN KK ) 46 ( 4 ) 203 - 209 2013.12 [Refereed]

Respiratory syncytial virus (RSV) is the major infectious agent causing serious respiratory tract inflammation in infants and young children. However, an effective vaccine and anti-viral therapy for RSV infection have not yet been developed. Hop-derived bitter acids have potent pharmacological effects on inflammation. Therefore, we investigated the effects of humulone, which is the main constituent of hop bitter acids, on the replication of RSV and release of the proinflammatory cytokine IL-8 and chemokine RANTES in RSV-infected human nasal epithelial cells (HNECs). We found that humulone prevented the expression of RSV/G-protein, formation of virus filaments and release of IL-8 and RANTES in a dose-dependent manner in RSV-infected HNECs. These findings suggest that humulone has protective effects against the replication of RSV, the virus assembly and the inflammatory responses in HNECs and that it is a useful biological product for the prevention and therapy for RSV infection.

Regulation of tight junctions by sex hormones in normal human endometrial epithelial cells and uterus cancer cell line Sawano.

Someya M, Kojima T, Ogawa M, Ninomiya T, Nomura K, Takasawa A, Murata M, Tanaka S, Saito T, Sawada N

Cell and tissue research ( 2 ) 354 481 - 494 2013.11 [Refereed]

Tight junctions in human pancreatic duct epithelial cells.

Takashi Kojima, Hiroshi Yamaguchi, Tatsuya Ito, Daisuke Kyuno, Tsuyoshi Kono, Takumi Konno, Norimasa Sawada

Tissue barriers 1 ( 4 ) e24894 2013.10 [Refereed] [International journal]

Tight junctions of the pancreatic duct are essential regulators of physiologic secretion of the pancreas and disruption of the pancreatic ductal barrier is known to contribute to the pathogenesis of pancreatitis and progression of pancreatic cancer. Various inflammatory mediators and carcinogens can trigger tight junction disassembly and disruption of the pancreatic barrier, however signaling events that mediates such barrier dysfunctions remain poorly understood. This review focuses on structure and regulation of tight junctions in normal pancreatic epithelial cells and mechanisms of junctional disruption during pancreatic inflammation and cancer. We will pay special attention to a novel model of human telomerase reverse transcriptase-transfected human pancreatic ductal epithelial cells and will describe the roles of major signaling molecules such as protein kinase C and c-Jun N-terminal kinase in formation and disassembly of the pancreatic ductal barrier.

Protein kinase Cα inhibitor protects against downregulation of claudin-1 during epithelial-mesenchymal transition of pancreatic cancer.

Daisuke Kyuno, Takashi Kojima, Hiroshi Yamaguchi, Tatsuya Ito, Yasutoshi Kimura, Masafumi Imamura, Akira Takasawa, Masaki Murata, Satoshi Tanaka, Koichi Hirata, Norimasa Sawada

Carcinogenesis 34 ( 6 ) 1232 - 43 2013.06 [Refereed] [International journal]

Protein kinase Cα (PKCα) is highly expressed in pancreatic cancer. However, the effects of PKCα on Snail and claudin-1, which play crucial roles in epithelial cell polarity during epithelial-mesenchymal transition (EMT), remain unclear. In this study, we investigated the mechanisms of regulation of Snail and claudin-1 via a PKCα signal pathway during EMT in pancreatic cancer cells and in normal human pancreatic duct epithelial cells (HPDEs). By immunostaining, overexpression of PKCα and downregulation of claudin-1 were observed in poorly differentiated human pancreatic cancer tissues and the pancreatic cancer cell line PANC-1. Treatment with the PKCα inhibitor Gö6976 transcriptionally decreased Snail and increased claudin-1 in PANC-1 cells. The PKCα inhibitor prevented upregulation of Snail and downregulation of claudin-1 during EMT induced by transforming growth factor-β1 (TGF-β1) treatment and under hypoxia in PANC-1 cells. The effects of the PKCα inhibitor were in part regulated via an extracellular signal-regulated kinase (ERK) signaling pathway. The PKCα inhibitor also prevented downregulation of the barrier function and fence function during EMT in well-differentiated pancreatic cancer cell line HPAC. In normal HPDEs, the PKCα inhibitor transcriptionally induced not only claudin-1 but also claudin-4, -7 and occludin without a change of Snail. Treatment with the PKCα inhibitor in normal HPDEs prevented downregulation of claudin-1 and occludin by TGF-β1 treatment and enhanced upregulation of claudin-1, -4, -7 and occludin under hypoxia. These findings suggest that PKCα regulates claudin-1 via Snail- and mitogen-activated protein kinase/ERK-dependent pathways during EMT in pancreatic cancer. Thus, PKCα inhibitors may be potential therapeutic agents against the malignancy of human pancreatic cancer cells.

Behavior of tricellulin during destruction and formation of tight junctions under various extracellular calcium conditions

Akira Takasawa, Takashi Kojima, Takafumi Ninomiya, Mitsuhiro Tsujiwaki, Masaki Murata, Satoshi Tanaka, Norimasa Sawada

CELL AND TISSUE RESEARCH ( SPRINGER ) 351 ( 1 ) 73 - 84 2013.01 [Refereed]

Tricellulin is an important component of tricellular tight junctions (TJs) and is involved in the formation of tricellular contacts. However, little is known about its regulation during the assembly and disassembly of tricellular TJs. By using the well-differentiated pancreatic cancer cell line HPAC, which highly expresses tricellulin at tricellular contacts, we have investigated changes in the localization, expression and phosphorylation of tricellulin and in its TJ functions as a barrier and fence during the destruction and formation of TJs induced by changes in the extracellular calcium concentration. During both extracellular Ca2+ depletion caused by EGTA treatment and Ca2+ repletion after Ca2+ starvation, the expression of tricellulin increased in whole lysates and in Triton-X-100-insoluble fractions without any change in its mRNA. The increases in immunoreactivity revealed by Western blotting were prevented by alkaline phosphatase treatment. Immunoprecipitation assays showed that tricellulin was phosphorylated on threonine residues when it increased after Ca2+ depletion and repletion. In the early stage after Ca2+ repletion, tricellulin was expressed not only at tricellular contacts but also in the cytoplasm and at bicellular borders. In confocal laser microscopy, tricellulin was observed at the apical-most regions and basolateral membranes of tricellular contacts after Ca2+ repletion. Knockdown of tricellulin delayed the recovery of the barrier and fence functions after Ca2+ repletion. Thus, the dynamic behavior of tricellulin during the destruction and formation of TJs under various extracellular calcium conditions seems to be closely associated with the barrier and fence functions of TJs.

Curcumin prevents replication of respiratory syncytial virus and the epithelial responses to it in human nasal epithelial cells.

Kazufumi Obata, Takashi Kojima, Tomoyuki Masaki, Tamaki Okabayashi, Shinichi Yokota, Satoshi Hirakawa, Kazuaki Nomura, Akira Takasawa, Masaki Murata, Satoshi Tanaka, Jun Fuchimoto, Nobuhiro Fujii, Hiroyuki Tsutsumi, Tetsuo Himi, Norimasa Sawada

PloS one 8 ( 9 ) e70225 2013 [International journal]

The human nasal epithelium is the first line of defense during respiratory virus infection. Respiratory syncytial virus (RSV) is the major cause of bronchitis, asthma and severe lower respiratory tract disease in infants and young children. We previously reported in human nasal epithelial cells (HNECs), the replication and budding of RSV and the epithelial responses, including release of proinflammatory cytokines and enhancement of the tight junctions, are in part regulated via an NF-κB pathway. In this study, we investigated the effects of the NF-κB in HNECs infected with RSV. Curcumin prevented the replication and budding of RSV and the epithelial responses to it without cytotoxicity. Furthermore, the upregulation of the epithelial barrier function caused by infection with RSV was enhanced by curcumin. Curcumin also has wide pharmacokinetic effects as an inhibitor of NF-κB, eIF-2α dephosphorylation, proteasome and COX2. RSV-infected HNECs were treated with the eIF-2α dephosphorylation blocker salubrinal and the proteasome inhibitor MG132, and inhibitors of COX1 and COX2. Treatment with salubrinal, MG132 and COX2 inhibitor, like curcumin, prevented the replication of RSV and the epithelial responses, and treatment with salubrinal and MG132 enhanced the upregulation of tight junction molecules induced by infection with RSV. These results suggest that curcumin can prevent the replication of RSV and the epithelial responses to it without cytotoxicity and may act as therapy for severe lower respiratory tract disease in infants and young children caused by RSV infection.

Hop water extract inhibits double-stranded RNA-induced thymic stromal lymphopoietin release from human nasal epithelial cells

Jun Fuchimoto, Takashi Kojima, Naoyuki Kobayashi, Tsuyoshi Ohkuni, Noriko Ogasawara, Tomoyuki Masaki, Kazufumi Obata, Kazuaki Nomura, Atsushi Kondoh, Tatsuro Shigyo, Tetsuo Himi, Norimasa Sawada

AMERICAN JOURNAL OF RHINOLOGY & ALLERGY ( OCEAN SIDE PUBLICATIONS INC ) 26 ( 6 ) 433 - 438 2012.11 [Refereed]

Background: Thymic stromal lymphopoietin (TSLP) acts as a master switch for allergic inflammation and plays a key role in allergic diseases, including allergic rhinitis. Double-stranded RNA (dsRNA) recognized by Toll-like receptor 3 (TLR3) strongly activates TSLP release from human nasal epithelial cells (HNECs). Hop (Humulus lupulus L.) extracts have been shown to have potent pharmacologic effects on inflammation. Methods: To investigate whether a hop water extract (HWE) prevents TSLP release from HNECs, human telomerase reverse transcriptase (hTERT)-transfected HNECs, used as a model of normal HNECs, were pretreated with HWE before treatment with the TLR3 ligand Polyinosine-polycytidylic acid (poly[I:C]). Results: In the hTERT-transfected HNECs, treatment with HWE significantly reduced poly(I:C)-induced production and release of TSLP in a dose-dependent manner, as well as dexamethasone. Treatment with the protein kinase C (PKC) inhibitor GF109203X and NF-kappa B inhibitor IMD-0354 also reduced poly(I:C)-induced TSLP release from hTERT-transfected HNECs. Treatment with HWE efficiently prevented up-regulation of PKC activity by 12-O-tetradecanoyl phorbol-13-acetate but not NF-kappa B activity induced by IL-1 beta in hTERT-transfected HNECs. Conclusion: Our results clearly indicated that HWE inhibited dsRNA-induced production and release of TSLP via a PKC signal pathway in HNECs and it may have potent preventive effects against allergic rhinitis.

Targeting claudin-4 in human pancreatic cancer.

Takashi Kojima, Daisuke Kyuno, Norimasa Sawada

Expert opinion on therapeutic targets 16 ( 9 ) 881 - 7 2012.09 [Refereed] [International journal]

INTRODUCTION: Pancreatic cancer is one of the most malignant human diseases and there is an urgent need to develop novel diagnostic and therapeutic strategies. Claudin-4, overexpressed in pancreatic cancer and its precursor lesions, is a receptor for Clostridium perfringens enterotoxin (CPE). The cytotoxic effects of CPE and monoclonal antibodies against claudin-4 are useful as novel therapeutic tools for pancreatic cancer. AREAS COVERED: This review describes and discusses the studies targeting claudin-4 in normal human pancreatic duct epithelial (HPDE) cells and cancer cells. EXPERT OPINION: Claudin-4 is in part regulated via a PKCα signal transduction pathway in pancreatic cancer cell lines. PKCα inhibitors may represent potential therapeutic agents against human pancreatic cancer cells by the use of CPE cytotoxicity via claudin-4. The COOH-terminal half fragment of CPE (C-CPE) enhances the effectiveness of clinically relevant chemotherapies and can be used as a carrier for drugs and other bacterial toxins to claudin-4-positive cancer cells. hTERT-HPDE cells, in which the human telomerase reverse transcriptase (hTERT) gene is introduced into normal HPDE cells, may be a useful model of normal HPDE cells not only for physiological regulation of claudin-4 expression but also for developing safer and more effective therapeutic methods targeting claudin-4 in pancreatic cancer.

【EMTのUP DATE】EMTと膵癌

及能大輔, 小島隆, 山口洋志, 伊東竜哉, 高澤啓, 村田雅樹, 今村将史, 木村康利, 澤田典均, 平田公一

Surgery Frontier ( (株)メディカルレビュー社 ) 19 ( 3 ) 305 - 310 2012.09

膵癌では、原発巣において腺腔構造を維持していた癌細胞が低分化な紡錘形細胞となって移動し、再び高分化な転移巣を形成しているかのような像がしばしば観察される。このような形態変化は、膵癌の浸潤・転移における上皮間葉移行(epithelial-mesenchymal transition;EMT)の特徴像とされている。膵癌のEMT誘導因子には、さまざまなサイトカインや増殖因子、癌周囲微小環境などが挙げられているが、なかでもTGF-βが中心的な役割を担っていると考えられている。EMT誘導因子はSnail、Slug、ZEB1、SIP1、E2A、Twistなどの転写因子を活性化し、あるいはmicroRNAなどを制御した結果、E-cadherinなどの上皮系マーカーを転写レベルで抑制し、N-cadherinなどの間葉系マーカーの発現を転写レベルで促進させ、癌細胞が細胞間接着を喪失し、高い運動性や浸潤能を獲得し、局所浸潤や他臓器転移をもたらすとされている。膵癌のEMTについての研究は、癌の浸潤・転移のメカニズムの理解につながり、膵癌の新規診断・治療法に寄与するものと思われる。(著者抄録)

Epidermal growth factor modulates claudins and tight junctional functions in ovarian cancer cell lines.

Ogawa M, Kojima T, Someya M, Nomura K, Takasawa A, Murata M, Tanaka S, Saito T, Sawada N

Histochemistry and cell biology ( 2 ) 138 323 - 338 2012.08 [Refereed]

A novel autocrine-paracrine loop of TSLP in atopic dermatitis is modulated by p63

Kubo Terufumi, Ye Rui, Ara Shihoko, Matsumiya Hiroshi, Kojima Takashi, Kikuchi Tomoki, Sato Noriyuki, Ichimiya Shingo

JOURNAL OF IMMUNOLOGY 188 2012.05 [Refereed]

Claudin-4-targeted therapy using Clostridium perfringens enterotoxin for prostate cancer.

Toshihiro Maeda, Masaki Murata, Hideki Chiba, Akira Takasawa, Satoshi Tanaka, Takashi Kojima, Naoya Masumori, Taiji Tsukamoto, Norimasa Sawada

The Prostate 72 ( 4 ) 351 - 60 2012.03 [International journal]

BACKGROUND: Clostridium perfringens enterotoxin (CPE) triggers lysis of epithelial cells through binding to tight-junction proteins claudin-3 (Cldn3) and Cldn4, which are over-expressed in prostate cancer. We investigated the potential of Cldn-targeted therapy using CPE. METHODS: We investigated the expression levels and subcellular localization of Cldn3 and Cldn4 in primary human prostate cancer tissues, human prostate cancer cell lines (22Rv1, DU145, and PC3) and normal human prostate epithelial cells (PrECs). Cytotoxic effects of CPE on these cells were examined by colorimetric assay. We studied whether knockdown of Cldn3 and/or Cldn4 expression using RNA interference influenced CPE-mediated cytotoxicity. The therapeutic effect of CPE was evaluated in PC3 xenografts in athymic mice. RESULTS: Cldn4 and Cldn3 were expressed in primary human prostate cancer tissues, 22Rv1, DU145, and PC3. Cldn4 protein was expressed in PrEC. Cldn4 was distributed along whole cell membranes of the cancer cell lines, whereas it was localized at tight junctions in PrEC. CPE-mediated cytotoxicity was greatly detected in PC3, but was hardly detectable in PrEC. Reduced expression of Cldn4, but not Cldn3, led to remarkable decreases of cytotoxicity in both PC3 and 22Rv1. The injection of CPE around PC3 xenografts significantly suppressed tumor growth. CONCLUSION: CPE-mediated cytotoxicity was observed in human prostate cancer cell lines, but barely detected in normal human PrECs. The cytotoxic effect depended not only on the expression level of Cldn4 protein but also on its subcellular localization. These results suggest that Cldn4-targeted therapy using CPE may be a new treatment for prostate cancer.

The role of IL-33 and its receptor ST2 in human nasal epithelium with allergic rhinitis

R. Kamekura, T. Kojima, K. Takano, M. Go, N. Sawada, T. Himi

CLINICAL AND EXPERIMENTAL ALLERGY ( WILEY ) 42 ( 2 ) 218 - 228 2012.02 [Refereed]

Background Interleukin (IL)-33 is a novel member of the IL-1 cytokine family and a ligand for the orphan IL-1 family receptor ST2. The IL-33 induces T helper 2-type inflammatory responses and is considered to play a crucial rule in allergic inflammations, such as asthma and atopic dermatitis. However, the role of IL-33 and its receptor ST2 in allergic rhinitis remains unknown. Objective We investigated expression of IL-33 and ST2 in the nasal epithelium of patients with allergic rhinitis and the mechanisms of the production of cytokines/chemokines induced by treatment with IL-33 using normal human nasal epithelial cells (HNECs) in vitro. Methods Expression of IL-33 and ST2 in normal and allergic rhinitis nasal mucosa was evaluated by reverse transcription-and real-time polymerase chain reactions and immunohistochemical methods. The IL-33 in serum, and IL-8 and GM-CSF were measured by ELISA. For in vitro experiments, HNECs in primary culture were used. Results The IL-33 levels in the sera of patients with allergic rhinitis were significantly higher than that in normal controls. Expression of IL-33 and ST2 was significantly elevated in the epithelium from patients with allergic rhinitis. The IL-33 mRNA in HNECs in vitro was significantly induced by treatment with IFN-gamma and the toll-like receptor 9 ligand ODN2006. The IL-33-induced production of IL-8 and GM-CSF from HNECs in vitro was significantly suppressed by corticosteroid treatment and distinct signal transduction inhibitors of ERK, p38 MAPK, JNK, NF-kappa B and epidermal growth factor receptor. Conclusions and Clinical Relevance The IL-33 and its receptor ST2 play important roles in allergic rhinitis. The IL-33-mediated inflammatory responses via ST2 are regulated by distinct signalling pathways in HNECs and the IL-33/ST2 pathway may provide new therapeutic targets for allergic rhinitis.

Regulation of tight junctions in human normal pancreatic duct epithelial cells and cancer cells

Takashi Kojima, Norimasa Sawada

BARRIERS AND CHANNELS FORMED BY TIGHT JUNCTION PROTEINS I ( BLACKWELL SCIENCE PUBL ) 1257 85 - 92 2012 [Refereed]

To investigate the regulation of tight junction molecules in normal human pancreatic duct epithelial (HPDE) cells and pancreatic cancer cells, we introduced the human telomerase reverse transcriptase (hTERT) gene into HPDE cells in primary culture and compared them to pancreatic cancer cell lines. The hTERT-transfected HPDE cells were positive for PDE markers and expressed claudin-1, claudin-4, claudin-7, and claudin-18, occludin, tricellulin, marvelD3, JAM-A, zonula occludens (ZO)-1, and ZO-2. The tight junction molecules, including claudin-4 and claudin-18 of normal HPDE cells, were in part regulated via a protein kinase C signal pathway by transcriptional control. In addition, claudin-18 in normal HPDE cells and pancreatic cancer cells was markedly induced by a PKC activator, and claudin-18 in pancreatic cancer cells was also modified by DNA methylation. In the marvel family of normal HPDE cells and pancreatic cancer cells, tricellulin was upregulated via a c-Jun N-terminal kinase pathway, and marvelD3 was downregulated during Snail-induced epithelial-mesenchymal transition.

Protein kinase Cα inhibitor enhances the sensitivity of human pancreatic cancer HPAC cells to Clostridium perfringens enterotoxin via claudin-4.

Daisuke Kyuno, Takashi Kojima, Tatsuya Ito, Hiroshi Yamaguchi, Mitsuhiro Tsujiwaki, Akira Takasawa, Masaki Murata, Satoshi Tanaka, Koichi Hirata, Norimasa Sawada

Cell and tissue research 346 ( 3 ) 369 - 81 2011.12 [Refereed] [International journal]

Protein kinase C (PKC) is overexpressed in cancer, including pancreatic cancer, compared with normal tissue. Moreover, PKCα is considered one of the biomarkers for the diagnosis of cancers. In several human cancers, the claudin tight junction molecules are abnormally regulated and are thus promising molecular targets for diagnosis and therapy with Clostridium perfringens enterotoxin (CPE). In order to investigate the changes of tight junction functions of claudins via PKCα activation in pancreatic cancer cells, the well-differentiated human pancreatic cancer cell line HPAC, with its highly expressed tight junction molecules and well-developed barrier function, was treated with the PKC activator 12-O-tetradecanoylphorbol 13-acetate (TPA). Treatment with TPA modified the activity of phosphoPKCα and caused an increase of the Snail family members Snail, Slug and Smad-interacting protein 1 and a decrease of E-cadherin. In HPAC cells treated with TPA, downregulation of claudin-1 and mislocalization of claudin-4 and occludin around the nuclei were observed, together with a decrease in the numbers of tight junction strands and an increase in phosphorylation of claudin-4. The barrier function and the cytotoxicity of CPE were significantly decreased on TPA treatment. All such changes after TPA treatment were prevented by inhibitors of panPKC and PKCα. These findings suggest that, in human pancreatic cancer cells, PKCα activation downregulates tight junction functions as a barrier and as a receptor of CPE via the modification of claudin-1 and -4 during epithelial to mesenchymal transition-like changes. PKCα inhibitors might represent potential therapeutic agents against human pancreatic cancer cells by use of CPE cytotoxicity via claudin-4.

Downregulation of tight junction-associated MARVEL protein marvelD3 during epithelial-mesenchymal transition in human pancreatic cancer cells.

Takashi Kojima, Akira Takasawa, Daisuke Kyuno, Tatsuya Ito, Hiroshi Yamaguchi, Koichi Hirata, Mitsuhiro Tsujiwaki, Masaki Murata, Satoshi Tanaka, Norimasa Sawada

Experimental cell research 317 ( 16 ) 2288 - 98 2011.10 [Refereed] [International journal]

The novel tight junction protein marvelD3 contains a conserved MARVEL (MAL and related proteins for vesicle trafficking and membrane link) domain like occludin and tricellulin. However, little is yet known about the detailed role and regulation of marvelD3 in normal epithelial cells and cancer cells, including pancreatic cancer. In the present study, we investigated marvelD3 expression in well and poorly differentiated human pancreatic cancer cell lines and normal pancreatic duct epithelial cells in which the hTERT gene was introduced into human pancreatic duct epithelial cells in primary culture, and the changes of marvelD3 during Snail-induced epithelial-mesenchymal transition (EMT) under hypoxia, TGF-β treatment and knockdown of FOXA2 in well differentiated pancreatic cancer HPAC cells. MarvelD3 was transcriptionally downregulated in poorly differentiated pancreatic cancer cells and during Snail-induced EMT of pancreatic cancer cells in which Snail was highly expressed and the fence function downregulated, whereas it was maintained in well differentiated human pancreatic cancer cells and normal pancreatic duct epithelial cells. Depletion of marvelD3 by siRNAs in HPAC cells resulted in downregulation of barrier functions indicated as a decrease in transepithelial electric resistance and an increase of permeability to fluorescent dextran tracers, whereas it did not affect fence function of tight junctions. In conclusion, marvelD3 is transcriptionally downregulated in Snail-induced EMT during the progression for the pancreatic cancer.

Effects of Clostridium perfringens enterotoxin via claudin-4 on normal human pancreatic duct epithelial cells and cancer cells.

Hiroshi Yamaguchi, Takashi Kojima, Tatsuya Ito, Daisuke Kyuno, Yasutoshi Kimura, Masafumi Imamura, Koichi Hirata, Norimasa Sawada

Cellular & molecular biology letters 16 ( 3 ) 385 - 97 2011.09 [Refereed] [International journal]

The tight junction protein claudin-4 is frequently overexpressed in pancreatic cancer, and is also a receptor for Clostridium perfringens enterotoxin (CPE). The cytotoxic effects of CPE are thought to be useful as a novel therapeutic tool for pancreatic cancer. However, the responses to CPE via claudin-4 remain unknown in normal human pancreatic duct epithelial (HPDE) cells. We introduced the human telomerase reverse transcriptase (hTERT) gene into HPDE cells in primary culture as a model of normal HPDE cells in vitro. hTERT-HPDE cells treated with or without 10% FBS and pancreatic cancer cell lines PANC-1, BXPC3, HPAF-II and HPAC were treated with CPE. In Western blotting, the expression of claudin-4 protein in hTERT-HPDE cells treated with 10% FBS was as high as it was in all of the pancreatic cancer cell lines. In hTERT-HPDE cells with or without 10% FBS, cytotoxicity was not observed at any concentration of CPE, whereas in all pancreatic cancer cell lines, CPE had a dose-dependent cytotoxic effect. In hTERT-HPDE cells with 10% FBS, claudin-4 was localized in the apical-most regions, where there are tight junction areas, in which in all pancreatic cancer cell lines claudin-4 was found not only in the apical-most regions but also at basolateral membranes. In hTERT-HPDE cells with 10% FBS after treatment with CPE, downregulation of barrier function and claudin-4 expression at the membranes was observed. In HPAC cells, the sensitivity to CPE was significantly decreased by knockdown of claudin-4 expression using siRNA compared to the control. These findings suggest that, in normal HPDE cells, the lack of toxicity of CPE was probably due to the localization of claudin-4, which is different from that of pancreatic cancer cells. hTERT-HPDE cells in this culture system may be a useful model of normal HPDE cells not only for physiological regulation of claudin-4 expression but also for developing safer and more effective therapeutic methods targeting claudin-4 in pancreatic cancer.

Altered expression of claudin-1, claudin-7, and tricellulin regardless of human papilloma virus infection in human tonsillar squamous cell carcinoma

Atsushi Kondoh, Ken-Ichi Takano, Takashi Kojima, Tsuyoshi Ohkuni, Ryuta Kamekura, Noriko Ogasawara, Mitsuru Go, Norimasa Sawada, Tetsuo Himi

ACTA OTO-LARYNGOLOGICA ( INFORMA HEALTHCARE ) 131 ( 8 ) 861 - 868 2011.08 [Refereed]

Conclusions: Altered expression of claudin-1, claudin-7, and tricellulin in early tonsillar squamous cell carcinoma (SCC) independent of human papilloma virus (HPV) infection may lead to tumor progression. Objectives: Integral tight junction proteins, the claudins and tricellulin, play a crucial role in all tissues. HPV is significantly associated with tonsillar SCC. We sought to determine the expression of claudin-1, claudin-7, and tricellulin in HPV-infected and HPV-free tonsillar SCC. Methods: Twenty-eight tonsillar SCCs were studied by immunohistochemical analysis and real-time reverse transcription polymerase chain reaction with in situ hybridization analysis. Results: Compared with normal tissues, claudin-1 was strongly expressed, whereas claudin-7 and tricellulin were weakly expressed or were absent in primary SCC and metastatic lymph nodes. Claudin-7 and tricellulin were markedly reduced at all stages of tumor development. In situ hybridization analysis showed no correlation between HPV infection and altered expression of the tight junction proteins.

A nuclear factor-κB signaling pathway via protein kinase C δ regulates replication of respiratory syncytial virus in polarized normal human nasal epithelial cells.

Masaki T, Kojima T, Okabayashi T, Ogasawara N, Ohkuni T, Obata K, Takasawa A, Murata M, Tanaka S, Hirakawa S, Fuchimoto J, Ninomiya T, Fujii N, Tsutsumi H, Himi T, Sawada N

Molecular biology of the cell ( 13 ) 22 2144 - 2156 2011.07 [Refereed]

Transcriptional regulation of claudin-18 via specific protein kinase C signaling pathways and modification of DNA methylation in human pancreatic cancer cells.

Tatsuya Ito, Takashi Kojima, Hiroshi Yamaguchi, Daisuke Kyuno, Yasutoshi Kimura, Masafumi Imamura, Akira Takasawa, Masaki Murata, Satoshi Tanaka, Koichi Hirata, Norimasa Sawada

Journal of cellular biochemistry 112 ( 7 ) 1761 - 72 2011.07 [Refereed] [International journal]

Since claudin-18 (Cldn18) is overexpressed in precursor lesion PanIN and pancreatic duct carcinoma, it serves as a diagnostic marker and a target of immunotherapy. The stomach isoform of Cldn18, Cldn18a2 is regulated via a PKC/MAPK/AP-1-dependent pathway in PKC activator 12-O-tetradecanoylphorbol 13-acetate (TPA)-stimulated gastric cancer cells. However, little is known about how Cldn18 is regulated, not only in pancreatic duct carcinoma but also in normal human pancreatic duct epithelial cells (HPDE cells). In the present study, four pancreatic cancer cell lines, HPAF-II, HPAC, PANC-1 and BXPC3, and hTERT-HPDE cells in which the hTERT gene was introduced into HPDE cells in primary culture, were treated with TPA. In all human pancreatic cancer cell lines and hTERT-HPDE cells, Cldn18 mRNA indicated as Cldn18a2 was markedly induced by TPA and in well- or moderately differentiated human pancreatic cancer cells HPAF-II and HPAC and hTERT-HPDE cells, the protein was also strongly increased. The upregulation of Cldn18 by TPA in human pancreatic cancer cell lines was prevented by inhibitors of PKCδ, PKCε, and PKCα, whereas the upregulation of Cldn18 by TPA in hTERT-HPDE cells was prevented by inhibitors of PKCδ, PKCθ, and PKCα. Furthermore, a CpG island was identified within the coding sequence of the Cldn18 gene and treatment with the demethylating agent 5-azadeoxycytidine enhanced upregulation of Cldn18 by TPA in HPAF-II and HPAC, but not hTERT-HPDE cells. Our findings suggest that in human pancreatic cancer cells, Cldn18 is primarily regulated at the transcriptional level via specific PKC signaling pathways and modified by DNA methylation.

Poly(I:C) reduces expression of JAM-A and induces secretion of IL-8 and TNF-α via distinct NF-κB pathways in human nasal epithelial cells.

Ohkuni T, Kojima T, Ogasawara N, Masaki T, Fuchimoto J, Kamekura R, Koizumi J, Ichimiya S, Murata M, Tanaka S, Himi T, Sawada N

Toxicology and applied pharmacology ( 1 ) 250 29 - 38 2011.01 [Refereed]

Tricellulin Is Expressed in Autotypic Tight Junctions of Peripheral Myelinating Schwann Cells

Shin Kikuchi, Takafumi Ninomiya, Haruyuki Tatsumi, Norimasa Sawada, Takashi Kojima

JOURNAL OF HISTOCHEMISTRY & CYTOCHEMISTRY ( SAGE PUBLICATIONS LTD ) 58 ( 12 ) 1067 - 1073 2010.12 [Refereed]

Autotypic tight junctions are formed by tight junction-like structures in three regions of myelinating Schwann cells, the paranodal loops, Schmidt-Lanterman incisures, and outer/inner mesaxons, and various tight junction molecules, including claudin-19 and junctional adhesion molecule (JAM)-C. Our findings demonstrate the identification and subcellular distribution of a novel tricellular tight junction protein, tricellulin (TRIC), in the autotypic tight junctions of mouse myelinating Schwann cells, compared with the autotypic adherens junction protein E-cadherin and the autotypic tight junction protein JAM-C, which are expressed in the paranodal loops, Schmidt-Lanterman incisures, and mesaxons. In real-time RT-PCR, the expression level of TRIC mRNA was about 10-fold higher in the sciatic nerve than in the spinal cord or cerebrum. In immunostaining, TRIC signals were completely restricted to the peripheral nervous system (PNS) and strongly concentrated at the paranodal loops, Schmidt-Lanterman incisures, and mesaxons of myelinating Schwann cells. In addition, TRIC was expressed in the thin region of the paranode and there was a gap between TRIC and the Na(+) channel. Furthermore, TRIC was more distally located from the node than E-cadherin and was colocalized with JAM-C. It is possible that TRIC may be a component to maintain the integrity for PNS myelin function and morphology. This manuscript contains online supplemental material at http://www.jhc.org. Please visit this article online to view these materials. (J Histochem Cytochem 58:1067-1073, 2010)

c-Jun N-terminal kinase is largely involved in the regulation of tricellular tight junctions via tricellulin in human pancreatic duct epithelial cells.

Kojima T, Fuchimoto J, Yamaguchi H, Ito T, Takasawa A, Ninomiya T, Kikuchi S, Ogasawara N, Ohkuni T, Masaki T, Hirata K, Himi T, Sawada N

Journal of cellular physiology ( 3 ) 225 720 - 733 2010.11 [Refereed]

Transcriptional control of tight junction proteins via a protein kinase C signal pathway in human telomerase reverse transcriptase-transfected human pancreatic duct epithelial cells.

Yamaguchi H, Kojima T, Ito T, Kimura Y, Imamura M, Son S, Koizumi J, Murata M, Nagayama M, Nobuoka T, Tanaka S, Hirata K, Sawada N

The American journal of pathology ( 2 ) 177 698 - 712 2010.08 [Refereed]

PPARgamma agonists upregulate the barrier function of tight junctions via a PKC pathway in human nasal epithelial cells.

Ogasawara N, Kojima T, Go M, Ohkuni T, Koizumi J, Kamekura R, Masaki T, Murata M, Tanaka S, Fuchimoto J, Himi T, Sawada N

Pharmacological research : the official journal of the Italian Pharmacological Society ( 6 ) 61 489 - 498 2010.06 [Refereed]

Thymic stromal lymphopoietin induces tight junction protein claudin-7 via NF-kappaB in dendritic cells.

Kamekura R, Kojima T, Takashima A, Koizumi J, Ogasawara N, Go M, Takano K, Murata M, Tanaka S, Ichimiya S, Himi T, Sawada N

Histochemistry and cell biology ( 3 ) 133 339 - 348 2010.03 [Refereed]

Expression and localization of tricellulin in human nasal epithelial cells in vivo and in vitro

Tsuyoshi Ohkuni, Takashi Kojima, Noriko Ogasawara, Tomoyuki Masaki, Takafumi Ninomiya, Shin Kikuchi, Mitsuru Go, Ken-ichi Takano, Tetsuo Himi, Norimasa Sawada

MEDICAL MOLECULAR MORPHOLOGY ( SPRINGER TOKYO ) 42 ( 4 ) 204 - 211 2009.12 [Refereed]

Tricellulin was identified as the first marker of the tricellular tight junction, which forms at the meeting points of three cells, and it is required for the maintenance of the transepithelial barrier. Although it is also considered to be important for the mucosal barrier of the upper respiratory tract, little is known about its expression and localization. In the present study, we examined the expression and localization of tricellulin in normal human nasal epithelial cells in vivo and in vitro, especially using primary cultures and telomerase reverse transcriptase (hTERT)-transfected cells. In human nasal epithelial cells in vivo and in vitro, mRNA and protein of tricellulin were detected. It was localized not only at tricellular contacts but also at bicellular borders, and in part colocalized with occludin. In human nasal epithelium, by immunoelectron microscopy analysis, tricellulin-associated gold particles were observed around the junction-like structure of the uppermost region. By treatment with 10% fetal bovine serum (FBS), expression of tricellulin mRNA was weakly increased, whereas that of bicellular tight junction molecules was strongly increased, in real-time PCR. These results suggest that tricellulin is stably expressed in human nasal epithelial cells and may play an important role for the sealing of the corner at tricellular contacts to prevent infiltration by various inhaled viruses and antigens.

Induction of JAM-A during differentiation of human THP-1 dendritic cells.

Ogasawara N, Kojima T, Go M, Fuchimoto J, Kamekura R, Koizumi J, Ohkuni T, Masaki T, Murata M, Tanaka S, Ichimiya S, Himi T, Sawada N

Biochemical and biophysical research communications ( 3 ) 389 543 - 549 2009.11 [Refereed]

Thymic stromal lymphopoietin enhances tight-junction barrier function of human nasal epithelial cells.

Kamekura R, Kojima T, Koizumi J, Ogasawara N, Kurose M, Go M, Harimaya A, Murata M, Tanaka S, Chiba H, Himi T, Sawada N

Cell and tissue research ( 2 ) 338 283 - 293 2009.11 [Refereed]

Tight junction proteins and signal transduction pathways in hepatocytes.

Kojima T, Murata M, Yamamoto T, Lan M, Imamura M, Son S, Takano K, Yamaguchi H, Ito T, Tanaka S, Chiba H, Hirata K, Sawada N

Histology and histopathology ( 11 ) 24 1463 - 1472 2009.11 [Refereed]

Knockdown of tight junction protein claudin-2 prevents bile canalicular formation in WIF-B9 cells.

Son S, Kojima T, Decaens C, Yamaguchi H, Ito T, Imamura M, Murata M, Tanaka S, Chiba H, Hirata K, Sawada N

Histochemistry and cell biology ( 3 ) 131 411 - 424 2009.03 [Refereed]

IGF-I regulates tight-junction protein claudin-1 during differentiation of osteoblast-like MC3T3-E1 cells via a MAP-kinase pathway.

Hatakeyama N, Kojima T, Iba K, Murata M, Thi MM, Spray DC, Osanai M, Chiba H, Ishiai S, Yamashita T, Sawada N

Cell and tissue research ( 2 ) 334 243 - 254 2008.11 [Refereed]

Protein kinase C enhances tight junction barrier function of human nasal epithelial cells in primary culture by transcriptional regulation.

Koizumi J, Kojima T, Ogasawara N, Kamekura R, Kurose M, Go M, Harimaya A, Murata M, Osanai M, Chiba H, Himi T, Sawada N

Molecular pharmacology ( 2 ) 74 432 - 442 2008.08 [Refereed]

Expression of tight junction proteins in epithelium including Ck20-positive M-like cells of human adenoids in vivo and in vitro.

Takano K, Kojima T, Ogasawara N, Go M, Kikuchi S, Ninomiya T, Kurose M, Koizumi J, Kamekura R, Murata M, Tanaka S, Chiba H, Himi T, Sawada N

Journal of molecular histology ( 3 ) 39 265 - 273 2008.06 [Refereed]

Transforming growth factor-beta induces epithelial to mesenchymal transition by down-regulation of claudin-1 expression and the fence function in adult rat hepatocytes.

Kojima T, Takano K, Yamamoto T, Murata M, Son S, Imamura M, Yamaguchi H, Osanai M, Chiba H, Himi T, Sawada N

Liver international : official journal of the International Association for the Study of the Liver ( 4 ) 28 534 - 545 2008.04 [Refereed]

Induction of claudins in passaged hTERT-transfected human nasal epithelial cells with an extended life span.

Kurose M, Kojima T, Koizumi J, Kamekura R, Ninomiya T, Murata M, Ichimiya S, Osanai M, Chiba H, Himi T, Sawada N

Cell and tissue research ( 1 ) 330 63 - 74 2007.10 [Refereed]

Changes of gap and tight junctions during differentiation of human nasal epithelial cells using primary human nasal epithelial cells and primary human nasal fibroblast cells in a noncontact coculture system.

Koizumi J, Kojima T, Kamekura R, Kurose M, Harimaya A, Murata M, Osanai M, Chiba H, Himi T, Sawada N

The Journal of membrane biology ( 1-3 ) 218 1 - 7 2007.08 [Refereed]

A novel monoclonal antibody against the second extracellular loop of occludin disrupts epithelial cell polarity.

Tokunaga Y, Kojima T, Osanai M, Murata M, Chiba H, Tobioka H, Sawada N

The journal of histochemistry and cytochemistry : official journal of the Histochemistry Society ( 7 ) 55 735 - 744 2007.07 [Refereed]

Connexins induce and maintain tight junctions in epithelial cells.

Kojima T, Murata M, Go M, Spray DC, Sawada N

The Journal of membrane biology ( 1-3 ) 217 13 - 19 2007.06 [Refereed]

Oncostatin M induces upregulation of claudin-2 in rodent hepatocytes coinciding with changes in morphology and function of tight junctions.

Imamura M, Kojima T, Lan M, Son S, Murata M, Osanai M, Chiba H, Hirata K, Sawada N

Experimental cell research ( 9 ) 313 1951 - 1962 2007.05 [Refereed]

The nuclear receptor hepatocyte nuclear factor 4 alpha acts as a morphogen to induce the formation of microvilli

Hideki Chiba, Naoyuki Sakai, Masaki Murata, Makoto Osanai, Takafumi Ninomiya, Takashi Kojima, Norimasa Sawada

JOURNAL OF CELL BIOLOGY ( ROCKEFELLER UNIV PRESS ) 175 ( 6 ) 971 - 980 2006.12 [Refereed]

Microvilli are actin-based organelles found on apical plasma membranes that are involved in nutrient uptake and signal transduction. Numerous components, including ezrin/radixin/moesin (ERM) proteins, have been identified that link filamentous actins to transmembrane proteins, but the signals driving microvillus biogenesis are not known. In this study, we show that the conditional and/or ectopic expression of a nuclear receptor, hepatocyte nuclear factor 4 alpha (HNF4 alpha), triggers microvillus morphogenesis. We also demonstrate that HNF4 alpha expression induces ERM-binding phosphoprotein 50 (EBP50) expression and that attenuation of EBP50 using RNA interference inhibits microvillus development. We conclude that HNF4 alpha acts as a morphogen to trigger microvillus formation.

Connexin 26 expression prevents down-regulation of barrier and fence functions of tight junctions by Na+/K+-ATPase inhibitor ouabain in human airway epithelial cell line Calu-3.

Go M, Kojima T, Takano K, Murata M, Koizumi J, Kurose M, Kamekura R, Osanai M, Chiba H, Spray DC, Himi T, Sawada N

Experimental cell research ( 19 ) 312 3847 - 3856 2006.11 [Refereed]

Phosphorylation of ezrin enhances microvillus length via a p38 MAP-kinase pathway in an immortalized mouse hepatic cell line.

Lan M, Kojima T, Murata M, Osanai M, Takano K, Chiba H, Sawada N

Experimental cell research ( 2 ) 312 111 - 120 2006.01 [Refereed]

p53関連分子による胸腺ストローマの細胞間結合制御

小柴茂, 一宮慎吾, 小島隆, 外岡暁子, 村田雅樹, 木村幸子, 横山繁昭, 氷見徹夫, 佐藤昇志

日本免疫学会総会・学術集会記録 ( (NPO)日本免疫学会 ) 35 65 - 65 2005.11

Behavior of tight-junction, adherens-junction and cell polarity proteins during HNF-4 alpha-induced epithelial polarization

S Satohisa, H Chiba, M Osanai, S Ohno, T Kojima, T Saito, N Sawada

EXPERIMENTAL CELL RESEARCH ( ELSEVIER INC ) 310 ( 1 ) 66 - 78 2005.10 [Refereed]

We previously reported that expression of tight-junction molecules occludin, claudin-6 and claudin-7, as well as establishment of epithelial polarity, was triggered in mouse F9 cells expressing hepatocyte nuclear factor (HNF)-4 alpha [H. Chiba, T. Gotoh, T. Kojima, S. Satohisa, K. Kikuchi, M. Osanai, N. Sawada. Hepatocyte nuclear factor (HNF)-4a triggers formation of functional tight junctions and establishment of polarized epithelial morphology in F9 embryonal carcinoma cells, Exp. Cell Res. 286 (2003) 288-297]. Using these cells, we examined in the present study behavior of tight-junction, adherens-junction and cell polarity proteins and elucidated the molecular mechanism behind HNF-4 alpha-initiated junction formation and epithelial polarization. We herein show that not only ZO-1 and ZO-2, but also ZO-3, junctional adhesion molecule (JAM)-B, JAM-C and cell polarity proteins PAR-3, PAR-6 and atypical protein kinase C (aPKC) accumulate at primordial adherens junctions in undifferentiated F9 cells. In contrast, CRB3, Pals1 and PATJ appeared to exhibit distinct subcellular localization in immature cells, Induced expression of HNF-4 alpha led to translocation of these tight-junction and cell polarity proteins to beltlike tight junctions, where occludin, claudin-6 and claudin-7 were assembled, in differentiated cells. Interestingly, PAR-6, aPKC, CRB3 and Pals1, but not PAR-3 or PATJ, were also concentrated on the apical membranes in differentiated cells. These findings indicate that HNF-4 alpha provokes not only expression of tight-junction adhesion molecules, but also modulation of subcellular distribution of junction and cell polarity proteins, resulting in junction formation and epithelial polarization. (c) 2005 Elsevier Inc. All rights reserved.

Down-regulation of survival signaling through MAPK and Akt in occludin-deficient mouse hepatocytes in vitro.

Murata M, Kojima T, Yamamoto T, Go M, Takano K, Osanai M, Chiba H, Sawada N

Experimental cell research ( 1 ) 310 140 - 151 2005.10 [Refereed]

胸腺ストローマの細胞間結合とその制御

小柴茂, 一宮慎吾, 小島隆, 村田雅樹, 外岡暁子, 木村幸子, 横山繁昭, 氷見徹夫, 佐藤昇志

日本病理学会会誌 ( (一社)日本病理学会 ) 94 ( 1 ) 367 - 367 2005.03

胸腺スカフォールドの組織構築とその制御

小柴茂, 一宮慎吾, 小島隆, 近藤伸彦, 外岡暁子, 村田雅樹, 高桑麗子, 横山繁昭, 氷見徹夫, 佐藤昇志

日本免疫学会総会・学術集会記録 ( (NPO)日本免疫学会 ) 34 72 - 72 2004.11

Role of the p38 MAP-kinase signaling pathway for Cx32 and claudin-1 in the rat liver

Takashi Kojima, Toshinobu Yamamoto, Masaki Murata, Mengdong Lan, Ken-Ichi Takano, Mitsuru Go, Shingo Ichimiya, Hideki Chiba, Norimasa Sawada

Cell Communication and Adhesion 10 ( 4-6 ) 437 - 443 2003.07 [Refereed]

Liver regeneration and cholestasis are associated with adaptive changes in expression of gap and tight junctions through signal transduction. The roles of stress responsitive MAP-kinase, p38 MAP-kinase, in the signaling pathway for gap junction protein, Cx32, and tight junction protein, claudin-1, were examined in rat liver in vivo and in vitro, including regeneration following partial hepatectomy and cholestasis after common bile duct ligation. Changes in the expression and function of Cx32 and claudin-1 in hepatocytes in vivo were studied using the p38 MAP-kinase inhibitor SB203580. Following partial hepatectomy and common bile duct ligation, down-regulation of Cx32 protein was inhibited by SB203580 treatment. Up-regulation of claudin-1 protein was enhanced by SB203580 treatment after partial hepatectomy but not common bile duct ligation. However, no change of the Ki-67 labeling index (which is a marker for cell proliferation) in the livers treated with SB203580, was observed compared to that without SB203580 treatment. In primary cultures of rat hepatocytes, however, treatment with a p38 MAP-kinase activator, anisomycin, decreased Cx32 and claudin-1 protein levels. p38 MAP-kinase may be an important signaling pathway for regulation of gap and tight junctions in hepatocytes. Changes of gap and tight junctions during liver regeneration and cholestasis are shown to be in part controlled via the p38 MAP-kinase signaling pathway and are independent of cell growth.

Expression of p21(waf-1/cip-1) is significantly induced in the livers of LEC rats with chronic liver injury

N Sawada, T Kojima, H Obata, H Isomura, S Atsumi, M Sawaki, N Tsuzuki, H Tobioka, Y Kokai, M Satoh, M Mori

JAPANESE JOURNAL OF CANCER RESEARCH ( JAPANESE CANCER ASSOCIATION ) 87 ( 11 ) 1102 - 1105 1996.11 [Refereed]

It is reported that hepatocytes isolated from LEC rats with chronic liver injury show reduced growth activity in primary culture. To elucidate the molecular basis of this phenomenon, we examined expression of p21(waf-1/cip-1) and p27, cyclin-dependent kinase inhibitors, by northern blot analysis. The expression of p21(waf-1/cip-1) in the LEC rat liver was 3-fold higher than that of age-matched SD rat liver, while there was no significant difference in p27 expression level. Western blot analysis also revealed a significant increase in p21(waf-1/cip-1) in the nuclear matrix fraction of the LEC rat liver. Immunohistochemically, p21(waf-1/cip-1) was detected in the nuclei of normal LEC rat hepatocytes, but not in those of hepatocellular carcinoma cells, suggesting selective growth of neoplastic hepatocytes.

p21(waf-1/cip-1/sdi-1) is expressed at G1 phase in primary culture of hepatocytes from old rats, presumably preventing the cells from entering the S phase of the cell cycle

N Sawada, T Kojima, H Obata, M Saitoh, H Isomura, Y Kokai, M Satoh, M Mori

BIOCHEMICAL AND BIOPHYSICAL RESEARCH COMMUNICATIONS ( ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS ) 228 ( 3 ) 819 - 824 1996.11 [Refereed]

To elucidate whether p21(waf-1/cip-1/sdi-1) expression is associated with loss of growth potential of hepatocytes of old rats, we determined p21(waf-1/cip-1/sdi-1) expression of hepatocytes from old (30 months) rats during the cell cycle in primary culture. A high level of expression oi p21(waf-1/cip-1/sdi-1) was detected at the G1 phase in old-rat hepatocytes, but after the S phase in young-rat hepatocytes. Consistently, the incidence of the cells positive for p21(waf-1/cip-1/sdi-1) in nuclei before entering the S phase was significantly higher in old-rat hepatocytes than in young-rat hepatocytes. These results account for the loss of growth potential of old-rat hepatocytes in vitro and the marked retardation of regeneration of liver in old rats in vivo. (C) 1996 Academic Press, Inc.

Changes in cellular distribution of connexins 32 and 26 during formation of gap junctions in primary cultures of rat hepatocytes

T Kojima, M Yamamoto, H Tobioka, T Mizuguchi, T Mitaka, Y Mochizuki

EXPERIMENTAL CELL RESEARCH ( ACADEMIC PRESS INC JNL-COMP SUBSCRIPTIONS ) 223 ( 2 ) 314 - 326 1996.03 [Refereed]

In the adult rat hepatocyte, gap junction proteins consist of connexin 32 (Cx32) and connexin 26 (Cx26), Previously, we reported that both Cx32 and Cx26 were markedly induced and maintained in primary cultures of adult rat hepatocytes, The reappearing gap junctions were accompanied by increases in both the proteins and the mRNAs, and they were well maintained together with extensive gap junctional intercellular communication (GJIC) for more than 4 weeks. In the present study, we examined the cellular location of the gap junction proteins and the structures in the hepatocytes cultured in our system, using confocal laser microscopy and immunoelectron microscopy of cells processed for Cx32 and Cx26 immunocytochemistry and freeze-fracture analysis, In immunoelectron microscopy, the size of Cx32-immunoreactive gap junction structures on the plasma membrane increased with time of culture, and some of them were larger than those in liver sections in vivo. Freeze-fracture analysis also showed that the size of gap junction plaques increased and that the larger gap junction plaques were composed of densely packed particles. These results suggest that in this culture system, not only the synthesis of Ox proteins but also the size of the gap junction plaques was increased markedly. In the adluminal lateral membrane of the cells, Cx32-immunoreactive lines were observed and many small gap junction plaques were closely associated with a more developed tight junction network. In the basal region of the cells, small Cx32- and Cx26-immunoreactive dots were observed in the cytoplasm and several annular structures labeled with the antibody to Cx32 were observed in the cytoplasm, These results indicated the formation and degradation of gap junctions in the cultured hepatocytes. (C) 1996 Academic Press, Inc.

Effects of oxygen radical scavengers on connexins 32 and 26 expression in primary cultures of adult rat hepatocytes

T Kojima, T Mitaka, T Mizuguchi, Y Mochizuki

CARCINOGENESIS ( OXFORD UNIV PRESS UNITED KINGDOM ) 17 ( 3 ) 537 - 544 1996.03 [Refereed]

Although we recently reported our success in inducing and maintaining the gap junction proteins connexin 26 (Cx26) and connexin 32 (Cx32) in adult rat hepatocytes cultured in serum-free L-15 medium supplemented with epidermal growth factor, dimethylsulfoxide (DMSO) and glucagon, the mechanisms by which DMSO induces gap junctions are still not clear, It is known that DMSO is not only a differentiation reagent for various cells but also a powerful scavenger of oxygen radicals, In the present study, by using this culture system and the measurement of oxidative stress by the nitro blue tetrazolium (NBT) formazan assay, we have examined the effect of oxygen radical scavengers such as DMSO, dimethylthiourea (DMTU) and alpha-tocopherol on the expression of both Cxs and on gap junctional intercellular communication (GJIC), as compared to another differentiation reagent, hexamethylene-bis-acetamide (HMBA), DMSO and DMTU clearly inhibited the oxidative stress of the cultured hepatocytes, while alpha-tocopherol and HMBA did not, The expression of Cx26 and Cx32 in the cultured hepatocytes was markedly induced by DMSO and DMTU, Furthermore, extensive GJIC was also observed with DMSO and DMTU, These results suggest that the expression of gap junctions in the hepatocytes may be closely related to oxidative stress and that oxygen radical scavengers may be important substances in inducing this expression.

INDUCTION AND REGULATION OF CONNEXIN26 BY GLUCAGON IN PRIMARY CULTURES OF ADULT-RAT HEPATOCYTES

T KOJIMA, T MITAKA, Y SHIBATA, Y MOCHIZUKI

JOURNAL OF CELL SCIENCE ( COMPANY OF BIOLOGISTS LTD ) 108 2771 - 2780 1995.08 [Refereed]

In the adult rat hepatocyte, the gap junction proteins consist of a major component, connexin32 (Cx32) and a minor component, connexin26 (Cx26). Although we recently reported our success in inducing and maintaining Cx32 in adult rat hepatocytes cultured in serum-free L-15 medium supplemented with epidermal growth factor and 2% dimethyl sulfoxide, it was very difficult to induce Cx26 in the primary hepatocytes. In the present study, we found that the addition of 10(-7) M glucagon into the culture medium could dramatically induce Cx26 mRNA and protein. Although the expression of Cx32 mRNA was also influenced by glucagon, the increase of the expression was small. Immunocytochemically, Cx26-positive spots were observed between most adjacent cells and were co-localized with the Cx32-positive spots. We also examined whether 0.5 mM dibutyl cyclic AMP could induce expression of Cx26 in the cells. The effect of dexamethasone on the expression of Cx26 mRNA compared to that of Cx32 mRNA was examined. For the induction and maintenance of Cx26 mRNA, more than 10(-7) M dexamethasone was necessary in this culture. These results suggest that expression of Cx26 in hepatocytes may be regulated by the concentrations of glucagon and glucocorticoid hormones.

REAPPEARANCE AND LONG-TERM MAINTENANCE OF CONNEXIN32 IN PROLIFERATED ADULT-RAT HEPATOCYTES - USE OF SERUM-FREE L-15 MEDIUM SUPPLEMENTED WITH EGF AND DMSO

T KOJIMA, T MITAKA, DL PAUL, M MORI, Y MOCHIZUKI

JOURNAL OF CELL SCIENCE ( COMPANY OF BIOLOGISTS LTD ) 108 1347 - 1357 1995.04 [Refereed]

Intercellular communication, especially gap junctional communication, is thought to be one of the highly differentiated functions of hepatocytes. In primary cultures of rat hepatocytes, it has been considered that the maintenance and the reinduction of differentiated functions is very difficult. In the present study, we succeeded in inducing the gap junctional protein connexin32 (Cx32) in adult rat hepatocytes cultured in serum-free L-15 medium supplemented with epidermal growth factor (EGF) and dimethylsulfoxide (DMSO), When the hepatocytes were cultured in L-15 medium supplemented with 20 mM NaHCO3 and 10 ng/ml EGF in a 5% CO2:95% air incubator, the cells proliferated, Fluorescence immunocytochemistry showed spots immunoreactive to Cx32 on the cell membranes between adjacent cells until day 3, but only a few Cx32-positive spots were found after day 4. Western and northern blot analyses also showed that the amounts of both the protein and mRNA of Cx32 in the cells decreased with time in culture, However, when the cells were treated with 2% DMSO from day 4, the immunoreactive spots reappeared on the cell membranes from day 6 and both their number and intensity gradually increased, The reappearance of Cx32 was accompanied by increases in both the protein and mRNA of Cx32, Futhermore, the expression of Cx32 was well maintained, together with extensive gap junctional intercellular communication, for more than 4 weeks, In addition, ultrastructually, many gap junctional structures were observed between the hepatocytes, and the antibodies to Cx32 were shown to bind to those structures, This culture system may be useful for studies of the reconstruction of the gap junctional structure, the intracellular pathways of the proteins, and the regulation of synthesis and processing in differentiated hepatocytes.

RAPID APPEARANCE OF CONNEXIN 26-POSITIVE GAP-JUNCTIONS IN CENTRILOBULAR HEPATOCYTES WITHOUT INDUCTION OF MESSENGER-RNA AND PROTEIN-SYNTHESIS IN ISOLATED-PERFUSED LIVER OF FEMALE RAT

T KOJIMA, N SAWADA, M OYAMADA, H CHIBA, H ISOMURA, M MORI

JOURNAL OF CELL SCIENCE ( COMPANY OF BIOLOGISTS LTD ) 107 3579 - 3590 1994.12

In the adult rat liver, the gap junction protein connexin 32 (Cx32) is evenly distributed in hepatocytes within the liver lobules, while connexin 26 (Cx26) is: preferentially localized in hepatocytes in periportal zones. We report here that Cx26-positive gap junctions rapidly appear in the centrilobular hepatocytes of adult female rat livers during a 30 minute perfusion of the liver through the hepatic portal vein with a 1:1 mixture of Dulbecco's modified Eagle's medium (DMEM) and oxygen transport FC-43 fluid at a physiological flow rate without any changes in the distribution of Cx32. The change in the localization of Cx26 was closely related to that of E-cadherin, and there was no significant increase in the amounts of Cx26 protein and mRNA. The appearance of Cx26 in the centrilobular hepatocytes was inhibited by treatment with cytoskeleton disrupters such as colchicine and cytochalasin B, and intracytoplasmic transport inhibitors such as brefeldin A. The liver perfusion induced the appearance of Cx26 in the centrilobular hepatocytes only in female rats. Estrogen treatment of ovariectomized rats caused the appearance of both Cx26 and E-cadherin in centrilobular hepatocytes not only in the perfused liver but also in the non-perfused liver. Our results indicate that in the rat liver: (a) the localization of Cx26 can be modulated by a post-translational mechanism; (b) E-cadherin may play an important role in the formation of gap junctions composed of Cx26; and (c) the formation of gap junctions is regulated by female steroid hormones.

SEQUENTIAL-CHANGES IN INTERCELLULAR-JUNCTIONS BETWEEN HEPATOCYTES DURING THE COURSE OF ACUTE LIVER-INJURY AND RESTORATION AFTER THIOACETAMIDE TREATMENT

T KOJIMA, N SAWADA, Y ZHONG, M OYAMADA, M MORI

VIRCHOWS ARCHIV-AN INTERNATIONAL JOURNAL OF PATHOLOGY ( SPRINGER VERLAG ) 425 ( 4 ) 407 - 412 1994.11

Sequential changes of gap junctions (GJs), tight junctions (TJs) and desmosomes (DSs) between hepatocytes during restorative proliferation were studied in rats after a single intraperitoneal administration of 200 mg/kg thioacetamide (TAA). Antibody against connexin 32 was used to demonstrate GJs; simultaneously the changes in TJs and DSs were studied using antibodies against 7H6 protein and desmoplakins. Propidium iodide and bromodeoxyuridine were used to recognize necrotic and proliferative cells. GJs were evenly distributed in early necrotic hepatocytes at 16 h after TAA treatment, then disappeared from necrotic and surrounding cells at 24 h. At 48 h, GJs had disappeared completely from hepatocytes in whole liver lobules, while many hepatocytes were heavily labelled with BrdU. At 72 h, GJs reappeared, firstly in perinecrotic areas. At 96 h after treatment, when the injured areas had disappeared and restorative proliferation ceased, GJs were distributed evenly throughout the lobules. Immunohistochemical observation of GJs in centrilobular, perinecrotic and periportal areas after TAA-induced hepatic necrosis was confirmed by counting the number of connexin-32-positive spots in the respective areas. TJs and DSs disappeared from necrotic cells at 24 h, but then increased between 24 and 48 h in perinecrotic areas, though the increased intensity of these junctions was more evident at 48 h. At 72 h, localization of TJs and DSs returned to normal, These results suggest that during the course of acute hepatic injury, GJs (cell-cell communication) behave differently from other intercellular junctions.

Reappearance of gap junctions in primary cultures of rat hepatocytes

T MITAKA, T KOJIMA, Y MOCHIZUKI

ELECTRON MICROSCOPY 1994, VOLS 3A AND 3B ( EDITIONS PHYSIQUE ) 195 - 196 1994 [Refereed]

Hormonal Regulation of Connexin 43 Expression and Gap Junctional Communication in Human Osteoblastic Cells

Hideki Chiba, Norimasa Sawada, Masahito Oyamada, Takashi Kojima, Michio Mori

Cell Structure and Function 19 ( 3 ) 173 - 177 1994

We have recently shown that connexin 43 (Cx43), a major gap junction protein in osteoblasts, is expressed with an increase in cell density (CHIBA, H. et al. (1993). Cell Struc. Funct., 18: 419–426). In the present study, we examined what kinds of hormones and cytokines regulate the gap junction protein in osteoblastic cells, using a human osteoblastic cell line (SV-HFO) after reaching a confluent density to avoid influence of cell proliferation. Either retinoic acid (RA) or transforming growth factor-β1 (TGF-β1) induced the Cx43 expression of SV-HFO cells, as revealed by Northern blot analysis and immunocytochemistry. These modulators also increased gap junctional intercellular communication, in terms of the extent of dye transfer. On the other hand, la, 25-dihydroxyvitamin D3 did not influence the Cx43 expression and gap junctional intercellular communication of the cells. These results suggest that RA and TGF-β1 might maintain bone tissue as an organized tissue in vivo by increasing intercellular communication of osteoblastic cells. © 1994, Japan Society for Cell Biology. All rights reserved.

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