2017年1月
Functional loss of DHRS7C induces intracellular Ca2+ overload and myotube enlargement in C2C12 cells via calpain activation
AMERICAN JOURNAL OF PHYSIOLOGY-CELL PHYSIOLOGY
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- 巻
- 312
- 号
- 1
- 開始ページ
- C29
- 終了ページ
- C39
- 記述言語
- 英語
- 掲載種別
- 研究論文(学術雑誌)
- DOI
- 10.1152/ajpcell.00090.2016
- 出版者・発行元
- AMER PHYSIOLOGICAL SOC
Dehydrogenase/reductase member 7C (DHRS7C) is a newly identified NAD/NADHdependent dehydrogenase that is expressed in cardiac and skeletal muscle and localized in the endoplasmic/sarcoplasmic reticulum (ER/SR). However, its functional role in muscle cells remains to be fully elucidated. Here, we investigated the role of DHRS7C by analyzing mouse C2C12 myoblasts deficient in DHRS7C (DHRS7C-KO cells), overexpressing wild-type DHRS7C (DHRS7C-WT cells), or expressing mutant DHRS7C [ DHRS7C-Y191F or DHRS7C-K195Q cells, harboring point mutations in the NAD/NADH-dependent dehydrogenase catalytic core domain (YXXXK)]. DHRS7C expression was induced as C2C12 myoblasts differentiated into mature myotubes, whereas DHRS7C-KO myotubes exhibited enlarged cellular morphology after differentiation. Notably, both DHRS7C-Y191F and DHRS7C-K195Q cells also showed similar enlarged cellular morphology, suggesting that the NAD/NADH-dependent dehydrogenase catalytic core domain is pivotal for DHRS7C function. In DHRS7CKO, DHRS7C-Y191F, and DHRS7C-K195Q cells, the resting level of cytosolic Ca2+ and total amount of Ca2+ storage in the ER/SR were significantly higher than those in control C2C12 and DHRS7C-WT cells after differentiation. Additionally, Ca2+ release from the ER/SR induced by thapsigargin and 4-chloro-m-cresol was augmented in these cells and calpain, a calcium-dependent protease, was significantly activated in DHRS7C-KO, DHRS7C-Y191F, and DHRS7C-K195Q myotubes, consistent with the higher resting level of cytosolic Ca2+ concentration and enlarged morphology after differentiation. Furthermore, treatment with a calpain inhibitor abolished the enlarged cellular morphology. Taken together, our findings suggested that DHRS7C maintains intracellular Ca2+ homeostasis involving the ER/SR and that functional loss of DHRS7C leads to Ca2+ overload in the cytosol and ER/SR, resulting in enlarged cellular morphology via calpain activation.
- リンク情報
- ID情報
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- DOI : 10.1152/ajpcell.00090.2016
- ISSN : 0363-6143
- eISSN : 1522-1563
- Web of Science ID : WOS:000393887400004