Details of a Researcher - OGAWA Toshihumi

Papers - OGAWA Toshihumi

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心筋細胞のネクロプトーシスにおけるミトコンドリア動態の影響(Impact of Mitochondrial Dynamics on Necroptosis in Cardiomyocytes)

戸田悠貴, 矢野俊之, 久野篤史, 丹野雅也, 神津英至, 佐藤達也, 大和田渉, 舘越勇輝, 小川俊史, 清水将輝, 古橋眞人

日本循環器学会学術集会抄録集 ( (一社)日本循環器学会 ) 88回 PJ080 - 3 2024.03

High-intensity interval training using electrical stimulation ameliorates muscle fatigue in chronic kidney disease-related cachexia by restoring mitochondrial respiratory dysfunction.

Hiroyori Fusagawa, Tatsuya Sato, Takashi Yamada, Azuma Naito, Nao Tokuda, Nao Yamauchi, Nobutoshi Ichise, Toshifumi Ogawa, Takuro Karaushi, Atsushi Teramoto, Noritsugu Tohse

Frontiers in physiology 15 1423504 - 1423504 2024 [International journal]

BACKGROUND: Exercise, especially high-intensity interval training (HIIT), can increase mitochondrial respiratory capacity and enhance muscular endurance, but its systemic burden makes it difficult to safely and continuously prescribe for patients with chronic kidney disease (CKD)-related cachexia who are in poor general condition. In this study, we examined whether HIIT using electrical stimulation (ES), which does not require whole-body exercise, improves muscle endurance in the skeletal muscle of 5/6 nephrectomized rats, a widely used animal model for CKD-related cachexia. METHODS: Male Wistar rats (10 weeks old) were randomly assigned to a group of sham-operated (Sham) rats and a group of 5/6 nephrectomy (Nx) rats. HIIT was performed on plantar flexor muscles in vivo with supramaximal ES every other day for 4 weeks to assess muscle endurance, myosin heavy-chain isoforms, and mitochondrial respiratory function in Nx rats. A single session was also performed to identify upstream signaling pathways altered by HIIT using ES. RESULTS: In the non-trained plantar flexor muscles from Nx rats, the muscle endurance was significantly lower than that in plantar flexor muscles from Sham rats. The proportion of myosin heavy chain IIa/x, mitochondrial content, mitochondrial respiratory capacity, and formation of mitochondrial respiratory supercomplexes in the plantaris muscle were also significantly decreased in the non-trained plantar flexor muscles from Nx rats than compared to those in plantar flexor muscles from Sham rats. Treatment with HIIT using ES for Nx rats significantly improved these molecular and functional changes to the same degrees as those in Sham rats. Furthermore, a single session of HIIT with ES significantly increased the phosphorylation levels of AMP-activated protein kinase (AMPK) and p38 mitogen-activated protein kinase (MAPK), pathways that are essential for mitochondrial activation signaling by exercise, in the plantar muscles of both Nx and Sham rats. CONCLUSION: The findings suggest that HIIT using ES ameliorates muscle fatigue in Nx rats via restoration of mitochondrial respiratory dysfunction with activation of AMPK and p38 MAPK signaling. Our ES-based HIIT protocol can be performed without placing a burden on the whole body and be a promising intervention that is implemented even in conditions of reduced general performance status such as CKD-related cachexia.

DOI PubMed

Predictive modeling for the development of diabetes mellitus using key factors in various machine learning approaches

Marenao Tanaka, Yukinori Akiyama, Kazuma Mori, Itaru Hosaka, Kenichi Kato, Keisuke Endo, Toshifumi Ogawa, Tatsuya Sato, Toru Suzuki, Toshiyuki Yano, Hirofumi Ohnishi, Nagisa Hanawa, Masato Furuhashi

Diabetes Epidemiology and Management ( Elsevier BV ) 100191 - 100191 2023.12

DOI

Adenosine monophosphate deaminase in the endoplasmic reticulum-mitochondria interface promotes mitochondrial Ca2+ overload in type 2 diabetes rat hearts.

Arata Osanami, Tatsuya Sato, Yuki Toda, Masaki Shimizu, Atsushi Kuno, Hidemichi Kouzu, Toshiyuki Yano, Wataru Ohwada, Toshifumi Ogawa, Tetsuji Miura, Masaya Tanno

Journal of diabetes investigation 14 ( 4 ) 560 - 569 2023.04 [Domestic journal]

AIMS/INTRODUCTION: We previously showed that upregulation of myocardial adenosine monophosphate deaminase (AMPD) is associated with pressure overload-induced diastolic dysfunction in type 2 diabetes hearts. Here, we examined involvement of AMPD localized in the endoplasmic reticulum-mitochondria interface in mitochondrial Ca2+ overload and its pathological significance. MATERIALS AND METHODS: We used type 2 diabetes Otsuka Long-Evans Tokushima Fatty rats (OLETF) and non-diabetes Long-Evans Tokushima Otsuka Fatty rats (LETO) as well as AMPD3-overexpressing H9c2 cells and human embryonic kidney 293 cells. RESULTS: OLETF, but not LETO, showed diastolic dysfunction under the condition of phenylephrine-induced pressure overload. The levels of 90-kDa AMPD3 in outer mitochondrial membranes/endoplasmic reticulum and mitochondria-associated endoplasmic reticulum membrane (MAM) fractions were significantly higher in OLETF than in LETO. The area of the MAM quantified by electron microscopic analysis was 57% larger, mitochondrial Ca2+ level under the condition of pressure overload was 47% higher and Ca2+ retention capacity in MAM-containing crude mitochondria isolated before the pressure overloading was 21% lower in OLETF than in LETO (all P-values <0.05). Transfection of FLAG-AMPD3 in cells resulted in significant enlargement of the MAM area, and impairment in pyruvate/malate-driven adenosine triphosphate-stimulated and uncoupler-stimulated mitochondrial respiration compared with those in control cells. CONCLUSIONS: The findings suggest that 90-kDa AMPD3 localized in the endoplasmic reticulum-mitochondria interface promotes formation of the MAM, inducing mitochondrial Ca2+ overload and dysfunction in type 2 diabetes hearts.

DOI PubMed

Downregulation of extramitochondrial BCKDH and its uncoupling from AMP deaminase in type 2 diabetic OLETF rat hearts.

Toshifumi Ogawa, Hidemichi Kouzu, Arata Osanami, Yuki Tatekoshi, Tatsuya Sato, Atsushi Kuno, Yugo Fujita, Shoya Ino, Masaki Shimizu, Yuki Toda, Wataru Ohwada, Toshiyuki Yano, Masaya Tanno, Takayuki Miki, Tetsuji Miura

Physiological reports 11 ( 4 ) e15608 2023.02 [International journal]

Systemic branched-chain amino acid (BCAA) metabolism is dysregulated in cardiometabolic diseases. We previously demonstrated that upregulated AMP deaminase 3 (AMPD3) impairs cardiac energetics in a rat model of obese type 2 diabetes, Otsuka Long-Evans-Tokushima fatty (OLETF). Here, we hypothesized that the cardiac BCAA levels and the activity of branched-chain α-keto acid dehydrogenase (BCKDH), a rate-limiting enzyme in BCAA metabolism, are altered by type 2 diabetes (T2DM), and that upregulated AMPD3 expression is involved in the alteration. Performing proteomic analysis combined with immunoblotting, we discovered that BCKDH localizes not only to mitochondria but also to the endoplasmic reticulum (ER), where it interacts with AMPD3. Knocking down AMPD3 in neonatal rat cardiomyocytes (NRCMs) increased BCKDH activity, suggesting that AMPD3 negatively regulates BCKDH. Compared with control rats (Long-Evans Tokushima Otsuka [LETO] rats), OLETF rats exhibited 49% higher cardiac BCAA levels and 49% lower BCKDH activity. In the cardiac ER of the OLETF rats, BCKDH-E1α subunit expression was downregulated, while AMPD3 expression was upregulated, resulting in an 80% lower AMPD3-E1α interaction compared to LETO rats. Knocking down E1α expression in NRCMs upregulated AMPD3 expression and recapitulated the imbalanced AMPD3-BCKDH expressions observed in OLETF rat hearts. E1α knockdown in NRCMs inhibited glucose oxidation in response to insulin, palmitate oxidation, and lipid droplet biogenesis under oleate loading. Collectively, these data revealed previously unrecognized extramitochondrial localization of BCKDH in the heart and its reciprocal regulation with AMPD3 and imbalanced AMPD3-BCKDH interactions in OLETF. Downregulation of BCKDH in cardiomyocytes induced profound metabolic changes that are observed in OLETF hearts, providing insight into mechanisms contributing to the development of diabetic cardiomyopathy.

DOI PubMed

Nuclear translocation of MLKL enhances necroptosis by a RIP1/RIP3-independent mechanism in H9c2 cardiomyoblasts.

Shoya Ino, Toshiyuki Yano, Atsushi Kuno, Masaya Tanno, Hidemichi Kouzu, Tatsuya Sato, Tomohisa Yamashita, Wataru Ohwada, Arata Osanami, Toshifumi Ogawa, Yuki Toda, Masaki Shimizu, Tetsuji Miura

Journal of pharmacological sciences 151 ( 2 ) 134 - 143 2023.02 [Domestic journal]

Accumulating evidence suggests that necroptosis of cardiomyocytes contributes to cardiovascular diseases. Lethal disruption of the plasma membrane in necroptosis is induced by oligomers of mixed lineage kinase domain-like (MLKL) that is translocated to the membrane from the cytosol. However, the role played by cytoplasmic-nuclear shuttling of MLKL is unclear. Here, we tested the hypothesis that translocation of MLKL to the nucleus promotes the necroptosis of cardiomyocytes. Activation of the canonical necroptotic signaling pathway by a combination of TNF-α and zVAD (TNF/zVAD) increased nuclear MLKL levels in a RIP1-activity-dependent manner in H9c2 cells, a rat cardiomyoblast cell line. By use of site-directed mutagenesis, we found a nuclear export signal sequence in MLKL and prepared its mutant (MLKL-L280/283/284A), though a search for a nuclear import signal was unsuccessful. MLKL-L280/283/284A localized to both the cytosol and the nucleus. Expression of MLKL-L280/283/284A induced necroptotic cell death, which was attenuated by GppNHp, an inhibitor of Ran-mediated nuclear import, but not by inhibition of RIP1 activity or knockdown of RIP3 expression. GppNHp partly suppressed H9c2 cell death induced by TNF/zVAD treatment. These results suggest that MLKL that is translocated to the nucleus via RIP1-mediated necroptotic signaling enhances the necroptosis of cardiomyocytes through a RIP1-/RIP3-independent mechanism.

DOI PubMed

Abrupt Onset of Cardiac Tamponade in Sarcoidosis.

Toshiyuki Yano, Shin Hisahara, Nobutaka Nagano, Takahiro Noto, Toshifumi Ogawa, Ryo Nishikawa, Masayuki Koyama, Hidemichi Kouzu, Atsuko Muranaka, Akiyoshi Hashimoto, Shun Shimohama, Tetsuji Miura

International heart journal 62 ( 5 ) 1176 - 1181 2021.09 [Domestic journal]

Sarcoidosis is a systemic inflammatory disease characterized by the formation of noncaseating epithelioid granulomas. Multiple organs, including the lung, eyes, and skin, are involved in this disorder, and cardiac involvement is a major cause of morbidity and mortality in patients with this disorder. We present the case history of a 22-year-old man with neurosarcoidosis complicated by abrupt onset of cardiac tamponade. Cardiac tamponade is a rare but potentially fatal manifestation of sarcoidosis, which is treatable with glucocorticoid therapy. Including the present case, previously reported cases of sarcoidosis with cardiac tamponade are reviewed to delineate its clinical characteristics.

DOI PubMed

Xanthine oxidoreductase-mediated injury is amplified by upregulated AMP deaminase in type 2 diabetic rat hearts under the condition of pressure overload.

Yusuke Igaki, Masaya Tanno, Tatsuya Sato, Hidemichi Kouzu, Toshifumi Ogawa, Arata Osanami, Toshiyuki Yano, Atsushi Kuno, Takayuki Miki, Takashi Nakamura, Tetsuji Miura

Journal of molecular and cellular cardiology 154 21 - 31 2021.05 [International journal]

BACKGROUND: We previously reported that upregulated AMP deaminase (AMPD) contributes to diastolic ventricular dysfunction via depletion of the adenine nucleotide pool in a rat model of type 2 diabetes (T2DM), Otsuka Long-Evans-Tokushima Fatty rats (OLETF). Meanwhile, AMPD promotes the formation of substrates of xanthine oxidoreductase (XOR), which produces ROS as a byproduct. Here, we tested the hypothesis that a functional link between upregulated AMPD and XOR is involved in ventricular dysfunction in T2DM rats. METHODS AND RESULTS: Pressure-volume loop analysis revealed that pressure overloading by phenylephrine infusion induced severer left ventricular diastolic dysfunction (tau: 14.7 ± 0.8 vs 12.5 ± 0.7 msec, left ventricular end-diastolic pressure: 18.3 ± 1.5 vs 12.2 ± 1.3 mmHg, p < 0.05) and ventricular-arterial uncoupling in OLETF than in LETO, non-diabetic rats, though the baseline parameters were comparable in the two groups. While the pressure overload did not affect AMPD activity, it increased XOR activity both in OLETF and LETO, with OLETF showing significantly higher XOR activity than that in LETO (347.2 ± 17.9 vs 243.2 ± 6.1 μg/min/mg). Under the condition of pressure overload, myocardial ATP level was lower, and levels of xanthine and uric acid were higher in OLETF than in LETO. Addition of exogenous inosine, a product of AMP deamination, to the heart homogenates augmented XOR activity. OLETF showed 68% higher tissue ROS levels and 47% reduction in mitochondrial state 3 respiration compared with those in LETO. Overexpression of AMPD3 in H9c2 cells elevated levels of hypoxanthine and ROS and reduced the level of ATP. Inhibition of XOR suppressed the production of tissue ROS and mitochondrial dysfunction and improved ventricular function under the condition of pressure overload in OLETF. CONCLUSIONS: The results suggest that increases in the activity of XOR and the formation of XOR substrates by upregulated AMPD contribute to ROS-mediated diastolic ventricular dysfunction at the time of increased cardiac workload in diabetic hearts.

DOI PubMed

Postpartum Heart Failure Complicated With Thyroiditis: A Concealed Aggravator of Peripartum Cardiomyopathy?

Hidemichi Kouzu, Toshiyuki Yano, Nobutaka Nagano, Masayuki Koyama, Toshifumi Ogawa, Yugo Fujita, Atsuko Muranaka, Tetsuji Miura

The Canadian journal of cardiology 35 ( 6 ) 796.e1-796.e3 2019.06 [International journal]

The etiology of peripartum cardiomyopathy (PPCM) remains unestablished, but the involvement of abnormal autoimmunity has been suggested. We report a case of PPCM that was triggered by postpartum thyroiditis. Despite the presence of myocardial damage indicated by cardiac magnetic resonance imaging, the patient's cardiac function completely recovered with the addition of bromocriptine to standard therapies. We discuss the role of thyroid hormones in the development of PPCM through aggravation of a prolactin-dependent antiangiogenic effect, and we argue that more attention should be paid to postpartum thyroiditis as a novel risk factor for PPCM.

DOI PubMed

Successful Transcatheter Diagnosis and Medical Treatment of Right Atrial Involvement in IgG4-related Disease.

Toshiyuki Yano, Motohisa Yamamoto, Atsushi Mochizuki, Toshifumi Ogawa, Nobutaka Nagano, Takefumi Fujito, Junichi Nishida, Daigo Nagahara, Koki Abe, Takayuki Miki, Chisako Suzuki, Hiroki Takahashi, Hatsue Ishibashi-Ueda, Tetsuji Miura

International heart journal 59 ( 5 ) 1155 - 1160 2018.09 [Domestic journal]

IgG4-related disease (IgG4-RD) is a fibro-inflammatory disorder characterized by lymphoplasmacytic infiltration of numerous IgG4-positive plasma cells, leading to fibrous thickening in the affected tissue. Typical cardiovascular manifestations of IgG4-RD are periaortitis, coronary arteritis, and pericarditis. Rare cases of myocardial involvement in IgG4-RD have been reported, but surgical resection or open biopsy was required for the diagnosis in those cases. Here, we report a case in which percutaneous transcatheter biopsy under the guidance of intracardiac echocardiography was useful for diagnosis of IgG4-RD manifested as an intracavitary right atrial mass, extending into the superior vena cava. Successful transcatheter diagnosis of myocardial involvement of IgG4-RD led to immediate favorable response to steroid therapy. Including the present case, previous IgG4-RD cases with myocardial involvement are reviewed to delineate its clinical characteristics.

DOI PubMed

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Papers - OGAWA Toshihumi