研究者詳細 - 佐藤　達也

論文 - 佐藤　達也

分割表示 144 件中 1 - 20 件目／全件表示 >>

Effects of contraction frequency during high-intensity training on fatigue resistance and aerobic adaptations in mouse skeletal muscle.

Azuma Naito, Tatsuya Sato, Iori Kimura, Nao Tokuda, Nao Yamauchi, Hiroyori Fusagawa, Takashi Yamada

Journal of applied physiology (Bethesda, Md. : 1985) 2024年12月 [査読有り] [国際誌]

担当区分：筆頭著者

In high-intensity and sprint interval training, the frequency of contractions is typically higher compared to moderate-intensity continuous training, but it remains unclear whether this contributes to the effective increase in fatigue resistance mechanisms. Here, we investigated the role of contraction frequency in high-intensity training on endurance adaptations of mouse skeletal muscle. Male C57BL/6 mice were divided into groups based on high (0.25 s contraction every 0.5 s) and low (0.25 s contraction every 4.5 s) contraction frequencies, with either 360 contractions per session (Hi360 and Lo360) or 30 contractions per session (Hi30 and Lo30). The plantar flexor muscles were stimulated using in vivo supramaximal electrical stimulation, where all muscle fibers were maximally activated, every other day for 5 weeks. In both the Hi360 and Lo360 groups, where force production declined to less than 40% of the initial value during the training session, muscle endurance, as well as mitochondrial content and respiratory capacity, were increased to a similar extent. In contrast, the rate of torque decline during the training session was more pronounced in the Hi30 group compared to the Lo30 group. In response, the Hi30 group, but not the Lo30 group, exhibited increased fatigue resistance and mitochondrial respiration, which was accompanied by increased PGC-1α expression and an activation of AMPK/Ulk1 pathway. These data suggest that the frequency of contractions is a critical factor in determining the efficient enhancement of mitochondrial respiratory capacity and muscle endurance through high-intensity training, presumably due to promotion of mitochondrial quality control.

A silent interplay between elevated intraocular pressure, glaucoma, and hypertension.

Tatsuya Sato, Araya Umetsu, Marenao Tanaka, Hiroshi Ohguro, Masato Furuhashi

Hypertension research : official journal of the Japanese Society of Hypertension 2024年12月 [査読有り] [国際誌]

担当区分：筆頭著者

High Intraocular Pressure Is Independently Associated With New-Onset Systemic Hypertension Over a 10-Year Period

Araya Umetsu, Marenao Tanaka, Tatsuya Sato, Yukinori Akiyama, Keisuke Endo, Kazuma Mori, Hirofumi Ohnishi, Megumi Watanabe, Hiroshi Ohguro, Nagisa Hanawa, Masato Furuhashi

Circulation Journal ( Japanese Circulation Society ) 2024年07月 [査読有り]

担当区分：筆頭著者

FABP4 Is an Indispensable Factor for Regulating Cellular Metabolic Functions of the Human Retinal Choroid.

Hiroshi Ohguro, Megumi Watanabe, Tatsuya Sato, Nami Nishikiori, Araya Umetsu, Megumi Higashide, Toshifumi Ogawa, Masato Furuhashi

Bioengineering (Basel, Switzerland) 11 ( 6 ) 2024年06月 [査読有り] [国際誌]

担当区分：責任著者

The purpose of the current study was to elucidate the physiological roles of intraocularly present fatty acid-binding protein 4 (FABP4). Using four representative intraocular tissue-derived cell types, including human non-pigmented ciliary epithelium (HNPCE) cells, retinoblastoma (RB) cells, adult retinal pigment epithelial19 (ARPE19) cells and human ocular choroidal fibroblast (HOCF) cells, the intraocular origins of FABP4 were determined by qPCR analysis, and the intracellular functions of FABP4 were investigated by seahorse cellular metabolic measurements and RNA sequencing analysis using a specific inhibitor for FABP4, BMS309403. Among these four different cell types, FABP4 was exclusively expressed in HOCF cells. In HOCF cells, both mitochondrial and glycolytic functions were significantly decreased to trace levels by BMS309403 in a dose-dependent manner. In the RNA sequencing analysis, 67 substantially up-regulated and 94 significantly down-regulated differentially expressed genes (DEGs) were identified in HOCF cells treated with BMS309403 and those not treated with BMS309403. The results of Gene Ontology enrichment analysis and ingenuity pathway analysis (IPA) revealed that the DEGs were most likely involved in G-alpha (i) signaling, cAMP-response element-binding protein (CREB) signaling in neurons, the S100 family signaling pathway, visual phototransduction and adrenergic receptor signaling. Furthermore, upstream analysis using IPA suggested that NKX2-1 (thyroid transcription factor1), HOXA10 (homeobox A10), GATA2 (gata2 protein), and CCAAT enhancer-binding protein A (CEBPA) were upstream regulators and that NKX homeobox-1 (NKX2-1), SFRP1 (Secreted frizzled-related protein 1) and TREM2 (triggering receptor expressed on myeloid cells 2) were causal network master regulators. The findings in this study suggest that intraocularly present FABP4 originates from the ocular choroid and may be a critical regulator for the cellular homeostasis of non-adipocyte HOCF cells.

The Specific ROCK2 Inhibitor KD025 Alleviates Glycolysis through Modulating STAT3-, CSTA- and S1PR3-Linked Signaling in Human Trabecular Meshwork Cells.

Megumi Watanabe, Tatsuya Sato, Araya Umetsu, Toshifumi Ogawa, Nami Nishikiori, Megumi Suzuki, Masato Furuhashi, Hiroshi Ohguro

Biomedicines 12 ( 6 ) 2024年05月 [査読有り] [国際誌]

担当区分：筆頭著者

To investigate the biological significance of Rho-associated coiled-coil-containing protein kinase (ROCK) 2 in the human trabecular meshwork (HTM), changes in both metabolic phenotype and gene expression patterns against a specific ROCK2 inhibitor KD025 were assessed in planar-cultured HTM cells. A seahorse real-time ATP rate assay revealed that administration of KD025 significantly suppressed glycolytic ATP production rate and increased mitochondrial ATP production rate in HTM cells. RNA sequencing analysis revealed that 380 down-regulated and 602 up-regulated differentially expressed genes (DEGs) were identified in HTM cells treated with KD025 compared with those that were untreated. Gene ontology analysis revealed that DEGs were more frequently related to the plasma membrane, extracellular components and integral cellular components among cellular components, and related to signaling receptor binding and activity and protein heterodimerization activity among molecular functions. Ingenuity Pathway Analysis (IPA) revealed that the detected DEGs were associated with basic cellular biological and physiological properties, including cellular movement, development, growth, proliferation, signaling and interaction, all of which are associated with cellular metabolism. Furthermore, the upstream regulator analysis and causal network analysis estimated IL-6, STAT3, CSTA and S1PR3 as possible regulators. Current findings herein indicate that ROCK2 mediates the IL-6/STAT3-, CSTA- and S1PR3-linked signaling related to basic biological activities such as glycolysis in HTM cells.

Tirzepatide ameliorates eating behaviors regardless of prior exposure to glucagon-like peptide receptor agonists in Japanese patients with type 2 diabetes mellitus

Toru Suzuki, Tatsuya Sato, Marenao Tanaka, Keisuke Endo, Kei Nakata, Toshifumi Ogawa, Itaru Hosaka, Yukinori Akiyama, Araya Umetsu, Masato Furuhashi

Journal of Diabetes and its Complications ( Elsevier BV ) 108779 - 108779 2024年05月 [査読有り]

担当区分：筆頭著者

3D culture induction of adipogenic differentiation in 3T3-L1 preadipocytes exhibits adipocyte-specific molecular expression patterns and metabolic functions

Keisuke Endo, Tatsuya Sato, Araya Umetsu, Megumi Watanabe, Fumihito Hikage, Yosuke Ida, Hiroshi Ohguro, Masato Furuhashi

Heliyon ( Elsevier BV ) 9 ( 10 ) e20713 - e20713 2023年10月 [査読有り]

担当区分：筆頭著者

Skeletal muscle endurance declines with impaired mitochondrial respiration and inadequate supply of acetyl-CoA during muscle fatigue in 5/6 nephrectomized rats.

Hiroyori Fusagawa, Tatsuya Sato, Takashi Yamada, Yuki Ashida, Iori Kimura, Azuma Naito, Nao Tokuda, Nao Yamauchi, Nobutoshi Ichise, Yoshinori Terashima, Izaya Ogon, Atsushi Teramoto, Toshihiko Yamashita, Noritsugu Tohse

Journal of applied physiology (Bethesda, Md. : 1985) 2023年08月 [査読有り] [国際誌]

担当区分：筆頭著者

Chronic kidney disease (CKD)-related cachexia increases the risks of reduced physical activity and mortality. However, the physiological phenotype of skeletal muscle fatigue and changes in intramuscular metabolites during muscle fatigue in CKD-related cachexia remain unclear. In the present study, we performed detailed muscle physiological evaluation, analysis of mitochondrial function, and comprehensive analysis of metabolic changes before and after muscle fatigue in a 5/6 nephrectomized rat model of CKD. Wistar rats were randomized to a sham-operation (Sham) group that served as a control group or a 5/6 nephrectomy (Nx) group. Eight weeks after the operation, in situ torque and force measurements in plantar flexor muscles in Nx rats using electrical stimulation revealed a significant decrease in muscle endurance during subacute phase related to mitochondrial function. Muscle mass was reduced without changes in the proportions of fiber type-specific myosin heavy chain isoforms in Nx rats. Pyruvate-malate-driven state 3 respiration in isolated mitochondria were impaired in Nx rats. Protein expression levels of mitochondrial respiratory chain complexes III and V were decreased in Nx rats. Metabolome analysis revealed that the increased supply of acetyl CoA in response to fatigue was blunted in Nx rats. These findings suggest that CKD deteriorates skeletal muscle endurance in association with mitochondrial dysfunction and inadequate supply of acetyl-CoA during muscle fatigue.

Prostanoid FP and EP2 Receptor Agonists Induce Epithelial and Subepithelial Fibrogenetic Changes in Human Conjunctival Fibroblasts in Different Manners.

Yuri Tsugeno, Tatsuya Sato, Megumi Watanabe, Masato Furuhashi, Hiroshi Ohguro

Journal of ocular pharmacology and therapeutics : the official journal of the Association for Ocular Pharmacology and Therapeutics 39 ( 6 ) 404 - 414 2023年07月 [査読有り] [国際誌]

担当区分：筆頭著者

Purpose: To examine the effects of prostanoid FP and EP2 receptor agonists, PGF2α and Omidenepag (OMD), respectively, on the transforming growth factor beta (TGF-β2) induced conjunctival fibrogenesis. Methods: Two-dimension (2D) and three-dimension (3D) cultures of these fibroblasts were subjected to following analyses: (1) planar proliferation evaluated by transendothelial electron resistance (TEER) measurements, (2) real-time metabolic analyses, (3) subepithelial proliferation evaluated by 3D spheroid' size and stiffness measurements, and (4) the mRNA expression of extracellular matrix (ECM) molecules and their modulators. Results: TGF-β2 induced increase in the planar proliferation was significantly decreased or enhanced by PGF2α or OMD, respectively. The proportion of oxygen consumption required to drive ATP synthesis compared with that driving proton leakage was increased by PGF2α and OMD independently with TGF-β2. In contrast, maximal mitochondrial respiration was decreased by PGF2α and OMD, and the OMD-induced effect was further enhanced by the presence of TGF-β2. In addition, the TGF-β2 dependent increase in the glycolytic capacity was cancelled by PGF2α and/or OMD. Alternatively, subepithelial proliferation, as evidenced by the stiffness of the 3D spheroids, was substantially increased by both PGF2α and OMD, and these were differently modulated by TGF-β2. The expression of several related factors as above fluctuated among the conditions for both 2D and 3D and TGF-β2 untreated or treated cultures. Conclusion: The present findings indicate that the prostanoid FP or the EP2 receptor agonist may solely and differently induce the planar and subepithelial proliferation of HconF cells and these were also modulated by TGF-β2.

Potential favorable action of sodium-glucose cotransporter-2 inhibitors on sudden cardiac death: a brief overview.

Tatsuya Sato, Hidemichi Kouzu, Toshiyuki Yano, Ichiro Sakuma, Masato Furuhashi, Noritsugu Tohse

Frontiers in cardiovascular medicine 10 1159953 - 1159953 2023年05月 [査読有り] [国際誌]

担当区分：筆頭著者 , 責任著者

The primary pharmacological action of sodium-glucose co-transporter 2 (SGLT2) inhibitors is to inhibit the reabsorption of glucose and sodium ions from the proximal tubules of the kidney and to promote urinary glucose excretion. Notably, several clinical trials have recently demonstrated potent protective effects of SGLT2 inhibitors in patients with heart failure (HF) or chronic kidney disease (CKD), regardless of the presence or absence of diabetes. However, the impact of SGLT2 inhibitors on sudden cardiac death (SCD) or fatal ventricular arrhythmias (VAs), the pathophysiology of which is partly similar to that of HF and CKD, remains undetermined. The cardiorenal protective effects of SGLT2 inhibitors have been reported to include hemodynamic improvement, reverse remodeling of the failing heart, amelioration of sympathetic hyperactivity, correction of anemia and impaired iron metabolism, antioxidative effects, correction of serum electrolyte abnormalities, and antifibrotic effects, which may lead to prevent SCD and/or VAs. Recently, as possible direct cardiac effects of SGLT2 inhibitors, not only inhibition of Na+/H+ exchanger (NHE) activity, but also suppression of late Na+ current have been focused on. In addition to the indirect cardioprotective mechanisms of SGLT2 inhibitors, suppression of aberrantly increased late Na+ current may contribute to preventing SCD and/or VAs via restoration of the prolonged repolarization phase in the failing heart. This review summarizes the results of previous clinical trials of SGLT2 inhibitors for prevention of SCD, their impact on the indices of electrocardiogram, and the possible molecular mechanisms of their anti-arrhythmic effects.

Optimized protocol for quantification of mitochondrial non-heme and heme iron content in mouse tissues and cultured cells

Tatsuya Sato, Hsiang-Chun Chang, Konrad T. Sawicki, Hossein Ardehali

STAR Protocols 2023年03月 [査読有り]

担当区分：筆頭著者

Case report: Transient lactate elevation by intravenous insulin infusion therapy for diabetic ketoacidosis in a patient with mitochondrial DNA 3243 A > G mutation: A glycolysis rebooting syndrome?

Wataru Ohwada, Hidemichi Kouzu, Tatsuya Sato, Kahomi Sazawa, Azumi Matsui, Nobutaka Nagano, Masayuki Koyama, Noriko Ogasawara, Akifumi Takada, Toshiyuki Yano, Masato Furuhashi

Frontiers in cardiovascular medicine 10 1144925 - 1144925 2023年 [査読有り] [国際誌]

担当区分：責任著者

Mitochondrial disease, most cases of which are caused by mitochondrial DNA (mtDNA) mutation, is present with multiple phenotypes including diabetes mellitus, sensorineural hearing loss, cardiomyopathy, muscle weakness, renal dysfunction, and encephalopathy, depending on the degree of heteroplasmy. While mitochondria play an important role in intracellular glucose and lactate metabolism in insulin-sensitive tissues such as muscles, appropriate strategies for glycemic control have not yet been established in a patient with mitochondrial disease, which is often complicated by myopathy. Here, we describe the history of a 40-year-old man with mtDNA 3243A > G who had sensorineural hearing loss, cardiomyopathy, muscle wasting, and diabetes mellitus with stage 3 chronic kidney disease. He developed mild diabetic ketoacidosis (DKA) in the process of treatment for poor glycemic control with severe latent hypoglycemia. According to the standard therapy for DKA, he was treated with continuous intravenous insulin infusion therapy, which unexpectedly resulted in an abrupt and transient elevation in blood lactate levels without exacerbation of heart failure and kidney function. Since blood lactate levels are determined by the balance between lactate production and consumption, an abrupt and transient lactate elevation following intravenous insulin injection therapy may reflect not only enhanced glycolysis in insulin-sensitive tissues with mitochondrial dysfunction but also decreased lactate consumption in the sarcopenic skeletal muscle and failing heart. Intravenous insulin infusion therapy in patients with mitochondrial disease may unmask derangements of intracellular glucose metabolism in response to insulin signaling.

Addition of ROCK Inhibitors Alleviates Prostaglandin-Induced Inhibition of Adipogenesis in 3T3L-1 Spheroids.

Yosuke Ida, Tatsuya Sato, Araya Umetsu, Megumi Watanabe, Masato Furuhashi, Fumihito Hikage, Hiroshi Ohguro

Bioengineering (Basel, Switzerland) 9 ( 11 ) 2022年11月 [査読有り] [国際誌]

担当区分：筆頭著者

To elucidate the additive effects of the ROCK inhibitors (ROCK-i), ripasudil (Rip) and Y27632 on bimatoprost acid (BIM-A), a prostaglandin analog (PG), on adipose tissue, two- and three-dimensional (2D or 3D) cultures of 3T3-L1 cells, the most well characterized cells in the field of lipid research, were used. The cells were subjected to a variety of analyses including lipid staining, real-time cellular metabolic analysis, the mRNA expressions of genes related to adipogenesis and extracellular matrices (ECMs) as well as the sizes and physical properties of the 3D spheroids by a micro-squeezer. BIM-A induced strong inhibitory effects on most of the adipogenesis-related changes in the 2D and 3D cultured 3T3-L1 cells, including (1) the enlargement and softening of the 3D spheroids, (2) a dramatic enhancement in lipid staining and the expression of adipogenesis-related genes, and (3) a decrease in mitochondrial and glycolytic metabolic function. By adding ROCK-i to the BIM-A, most of these BIM-A-induced effects were cancelled. The collective findings reported herein suggest that ROCK-i eliminated the PG-induced suppression of adipogenesis in the 3T3-L1 cells, accompanied by the formation of enlarged 3D spheroids. Such effects of adding ROCK-i to a PG in preadipocytes on cellular properties appear to be associated with the suppression of PG-induced adverse effects, and provide additional insight into our understanding of lipid-related research.

FGF-2 enhances fibrogenetic changes in TGF-β2 treated human conjunctival fibroblasts.

Yuri Tsugeno, Masato Furuhashi, Tatsuya Sato, Megumi Watanabe, Araya Umetsu, Soma Suzuki, Yosuke Ida, Fumihito Hikage, Hiroshi Ohguro

Scientific reports 12 ( 1 ) 16006 - 16006 2022年09月 [査読有り] [国際誌]

担当区分：筆頭著者

The objective of the current study was to examine the effects of fibroblast growth factor-2 (FGF-2) on conjunctival fibrogenesis that was induced by the presence of transforming growth factor-β2 (TGF-β2). Two-dimension (2D) and three-dimension (3D) cultured human conjunctival fibroblasts (HconF) were used for this purpose. The 2D and 3D cultured HconF were characterized by transendothelial electrical resistance (TEER) and FITC dextran permeability measurements (2D), real-time metabolic analyses (2D), size and stiffness measurements (3D), and the mRNA expression of extracellular matrix molecules, their modulators, Tissue inhibitor of metalloproteinases and matrix metalloproteinases and ER-stress related genes (2D and 3D). FGF-2 significantly increased planar proliferation, as evidenced by TEER values and FITC dextran permeability, and shifted glucose metabolism to the energetic phenotype of 2D HconF cells, and the stiffness of the 3D spheroids, and these effects were further enhanced in the presence of TGF-β2. Analyses of the expression of possible candidate molecules involved in cell architecture and stress indicated that some additive effects caused by both factors were also recognized in some of these molecules. The findings reported herein indicate that the FGF-2, either along or additively with TGF- β2 increased the fibrogenetic changes on the plane as well as in the spatial space of HconF cells.

Case report: Successful combination therapy with double-filtration plasmapheresis and rituximab under the condition of the use of a sensor-augmented pump for type B insulin resistance syndrome.

Arata Osanami, Masatoshi Kanda, Tatsuya Sato, Chikako Akazawa, Shuhei Baba, Hiroaki Komatsu, Kazuyuki Murase, Tomohisa Yamashita, Toshiyuki Yano

Frontiers in endocrinology 13 997296 - 997296 2022年09月 [査読有り] [国際誌]

担当区分：責任著者

Type B insulin resistance syndrome (TBIR) is a rare disease characterized by refractory diabetes due to severe insulin resistance caused by anti-insulin receptor autoantibodies, and a standard treatment regimen for TBIR has not been established, leading to therapeutic difficulties and high mortality. Since TBIR is known to be associated with autoimmune diseases such as systemic lupus erythematosus (SLE), glucocorticoids are often used as key immunosuppressive agents. However, glucocorticoids have the potential to exacerbate the pathophysiology of TBIR by worsening insulin sensitivity, which leads to hyperglycemia and muscle wasting. Here, we report a case history of a 66-year-old man who was diagnosed as having TBIR in combination with SLE and Sjögren's syndrome with marked hyperglycemia, ketosis, and muscle wasting. He was successfully treated with combination therapy of double-filtration plasmapheresis (DFPP) and administration of the anti-CD20 monoclonal antibody rituximab without induction of glucocorticoid therapy while using a sensor-augmented insulin pump (SAP) to prevent hypoglycemia. Remission of diabetes was achieved without severe hypoglycemic events and his circulating insulin receptor antibodies became negative after seven months of initiation of these treatments. Based on the successful clinical courses of this case, our report suggests the possibility of an effective therapeutic regimen with DFPP and rituximab under the condition of the use of an SAP for a patient with TBIR without induction of glucocorticoids.

Hypoxia Differently Affects TGF-β2-Induced Epithelial Mesenchymal Transitions in the 2D and 3D Culture of the Human Retinal Pigment Epithelium Cells.

Soma Suzuki, Tatsuya Sato, Megumi Watanabe, Megumi Higashide, Yuri Tsugeno, Araya Umetsu, Masato Furuhashi, Yosuke Ida, Fumihito Hikage, Hiroshi Ohguro

International journal of molecular sciences 23 ( 10 ) 2022年05月 [査読有り] [国際誌]

担当区分：筆頭著者

The hypoxia associated with the transforming growth factor-β2 (TGF-β2)-induced epithelial mesenchymal transition (EMT) of human retinal pigment epithelium (HRPE) cells is well recognized as the essential underlying mechanism responsible for the development of proliferative retinal diseases. In vitro, three-dimensional (3D) models associated with spontaneous O2 gradients can be used to recapitulate the pathological levels of hypoxia to study the effect of hypoxia on the TGF-β2-induced EMT of HRPE cells in detail, we used two-dimensional-(2D) and 3D-cultured HRPE cells. TGF-β2 and hypoxia significantly and synergistically increased the barrier function of the 2D HRPE monolayers, as evidenced by TEER measurements, the downsizing and stiffening of the 3D HRPE spheroids and the mRNA expression of most of the ECM proteins. A real-time metabolic analysis indicated that TGF-β2 caused a decrease in the maximal capacity of mitochondrial oxidative phosphorylation in the 2D HRPE cells, whereas, in the case of 3D HRPE spheroids, TGF-β2 increased proton leakage. The findings reported herein indicate that the TGF-β2-induced EMT of both the 2D and 3D cultured HRPE cells were greatly modified by hypoxia, but during these EMT processes, the metabolic plasticity was different between 2D and 3D HRPE cells, suggesting that the mechanisms responsible for the EMT of the HRPE cells may be variable during their spatial spreading.

Aging is associated with increased brain iron through cortex-derived hepcidin expression.

Tatsuya Sato, Jason Solomon Shapiro, Hsiang-Chun Chang, Richard A Miller, Hossein Ardehali

eLife 11 2022年01月 [査読有り] [国際誌]

担当区分：筆頭著者

Iron is an essential molecule for biological processes, but its accumulation can lead to oxidative stress and cellular death. Due to its oxidative effects, iron accumulation is implicated in the process of aging and neurodegenerative diseases. However, the mechanism for this increase in iron with aging, and whether this increase is localized to specific cellular compartment(s), are not known. Here, we measured the levels of iron in different tissues of aged mice, and demonstrated that while cytosolic non-heme iron is increased in the liver and muscle tissue, only the aged brain cortex exhibits an increase in both the cytosolic and mitochondrial non-heme iron. This increase in brain iron is associated with elevated levels of local hepcidin mRNA and protein in the brain. We also demonstrate that the increase in hepcidin is associated with increased ubiquitination and reduced levels of the only iron exporter, ferroportin-1 (FPN1). Overall, our studies provide a potential mechanism for iron accumulation in the brain through increased local expression of hepcidin, and subsequent iron accumulation due to decreased iron export. Additionally, our data support that aging is associated with mitochondrial and cytosolic iron accumulation only in the brain and not in other tissues.

Enhanced glucose metabolism through activation of HIF-1α covers the energy demand in a rat embryonic heart primordium after heartbeat initiation.

Tatsuya Sato, Nobutoshi Ichise, Takeshi Kobayashi, Hiroyori Fusagawa, Hiroya Yamazaki, Taiki Kudo, Noritsugu Tohse

Scientific reports 12 ( 1 ) 74 - 74 2022年01月 [国際誌]

担当区分：筆頭著者 , 責任著者

The initiation of heartbeat is an essential step in cardiogenesis in the heart primordium, but it remains unclear how intracellular metabolism responds to increased energy demands after heartbeat initiation. In this study, embryos in Wistar rats at embryonic day 10, at which heartbeat begins in rats, were divided into two groups by the heart primordium before and after heartbeat initiation and their metabolic characteristics were assessed. Metabolome analysis revealed that increased levels of ATP, a main product of glucose catabolism, and reduced glutathione, a by-product of the pentose phosphate pathway, were the major determinants in the heart primordium after heartbeat initiation. Glycolytic capacity and ATP synthesis-linked mitochondrial respiration were significantly increased, but subunits in complexes of mitochondrial oxidative phosphorylation were not upregulated in the heart primordium after heartbeat initiation. Hypoxia-inducible factor (HIF)-1α was activated and a glucose transporter and rate-limiting enzymes of the glycolytic and pentose phosphate pathways, which are HIF-1α-downstream targets, were upregulated in the heart primordium after heartbeat initiation. These results suggest that the HIF-1α-mediated enhancement of glycolysis with activation of the pentose phosphate pathway, potentially leading to antioxidant defense and nucleotide biosynthesis, covers the increased energy demand in the beating and developing heart primordium.

Ultrastructural Assessment and Proteomic Analysis in Myofibrillogenesis in the Heart Primordium After Heartbeat Initiation in Rats.

Nobutoshi Ichise, Tatsuya Sato, Hiroyori Fusagawa, Hiroya Yamazaki, Taiki Kudo, Izaya Ogon, Noritsugu Tohse

Frontiers in physiology 13 907924 - 907924 2022年 [査読有り] [国際誌]

担当区分：筆頭著者 , 責任著者

Myofibrillogenesis is an essential process for cardiogenesis and is closely related to excitation-contraction coupling and the maintenance of heartbeat. It remains unclear whether the formation of myofibrils and sarcomeres is associated with heartbeat initiation in the early embryonic heart development. Here, we investigated the association between the ultrastructure of myofibrils assessed by transmission electron microscopy and their proteomic profiling assessed by data-independent acquisition mass spectrometry (DIA-MS) in the rat heart primordia before and after heartbeat initiation at embryonic day 10.0, when heartbeat begins in rats, and in the primitive heart tube at embryonic day 11.0. Bundles of myofilaments were scattered in a few cells of the heart primordium after heartbeat initiation, whereas there were no typical sarcomeres in the heart primordia both before and after heartbeat initiation. Sarcomeres with Z-lines were identified in cells of the primitive heart tube, though myofilaments were not aligned. DIA-MS proteome analysis revealed that only 43 proteins were significantly upregulated by more than 2.0 fold among a total of 7,762 detected proteins in the heart primordium after heartbeat initiation compared with that before heartbeat initiation. Indeed, of those upregulated proteins, 12 (27.9%) were constituent proteins of myofibrils and 10 (23.3%) were proteins that were accessories and regulators for myofibrillogenesis, suggesting that upregulated proteins that are associated with heartbeat initiation were enriched in myofibrillogenesis. Collectively, our results suggest that the establishment of heartbeat is induced by development of bundles of myofilaments with upregulated proteins associated with myofibrillogensis, whereas sarcomeres are not required for the initial heartbeat.

Commentary: Assessment of Hypertension Using Clinical Electrocardiogram Features: A First-Ever Review.

Tatsuya Sato

Frontiers in medicine 8 691330 - 691330 2021年 [査読有り] [国際誌]

担当区分：筆頭著者 , 最終著者 , 責任著者

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