1
|
Hu Y, Wang Z, Ge N, Huang T, Zhang M, Wang H. Sodium pump alpha-2 subunit (ATP1A2) alleviates cardiomyocyte anoxia-reoxygenation injury via inhibition of endoplasmic reticulum stress-related apoptosis. Can J Physiol Pharmacol 2018; 96:515-520. [PMID: 29394489 DOI: 10.1139/cjpp-2017-0349] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Previous studies have found decreased functional capacity of the sodium pump (Na+-K+-ATPase) alpha and beta subunits and recovery of Na+-K+-ATPase activity significantly decreased myocyte apoptosis in myocardial ischemia-reperfusion (I/R) injury. However, the potential role of the Na+-K+-ATPase α-2 subunit (ATP1A2) in cardiomyocyte anoxia-reoxygenation (A/R) injury has not been elucidated. Rat myocardial cells were subjected to siRNA transfection followed by A/R injury. Apoptosis and expression of endoplasmic reticulum (ER) stress proteins CHOP, GRP78, and caspase-12 were detected in 4 groups of cells: ATP1A2 siRNA + A/R, control siRNA + A/R, control, and A/R injury model. We found that apoptosis was significantly elevated in the ATP1A2 siRNA + A/R group as compared with control siRNA + A/R, control, and A/R injury model groups (p < 0.05, p < 0.01, and p < 0.05). Furthermore, expression of CHOP, GRP78, and caspase-12 were significantly elevated in the ATP1A2 siRNA + A/R group as compared with control siRNA + A/R, control, and A/R injury model groups (p < 0.05, p < 0.01, and p < 0.05). Our findings suggest that cardiomyocyte ATP1A2 is a target of A/R injury, and its cardioprotective function may be mediated via inhibiting the ER-stress-related apoptosis.
Collapse
Affiliation(s)
- Yulong Hu
- Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China.,Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Zheng Wang
- Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China.,Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Nannan Ge
- Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China.,Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Ting Huang
- Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China.,Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Mingchao Zhang
- Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China.,Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China
| | - Hegui Wang
- Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China.,Department of Cardiology, Yijishan Hospital of Wannan Medical College, Wuhu, China
| |
Collapse
|
2
|
Guo HC, Guo F, Zhang LN, Zhang R, Chen Q, Li JX, Yin J, Wang YL. Enhancement of Na/K pump activity by chronic intermittent hypobaric hypoxia protected against reperfusion injury. Am J Physiol Heart Circ Physiol 2011; 300:H2280-7. [DOI: 10.1152/ajpheart.01164.2010] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
Chronic intermittent hypobaric hypoxia (CIHH) has been shown to attenuate intracellular Na+ accumulation and Ca2+ overload during ischemia and reperfusion (I/R), both of which are closely related to the outcome of myocardial damage. Na/K pump plays an essential role in maintaining the equilibrium of intracellular Na+ and Ca2+ during I/R. It has been shown that enhancement of Na/K pump activity by ischemic preconditioning may be involved in the cardiac protection. Therefore, we tested whether Na/K pump was involved in the cardioprotection by CIHH. We found that Na/K pump current in cardiac myocytes of guinea pigs exposed to CIHH increased 1.45-fold. The K 1 and f 1, which reflect the portion of α1-isoform of Na/K pump, dramatically decreased or increased, respectively, in CIHH myocytes. Western blot analysis revealed that CIHH increased the protein expression of the α1-isoform by 76%, whereas the protein expression of the α2-isoform was not changed significantly. Na/K pump current was significantly suppressed in simulated I/R, and CIHH preserved the Na/K pump current. CIHH significantly improved the recovery of cell length and contraction during reperfusion. Furthermore, inhibition of Na/K pump by ouabain attenuated the protective effect afforded by CIHH. Collectively, these data suggest that the increase of Na/K pump activity following CIHH is due to the upregulating α1-isoform of Na/K pump, which may be one of the mechanisms of CIHH against I/R-induced injury.
Collapse
Affiliation(s)
- Hui-cai Guo
- Departments of 1Pharmacology and
- Toxicology, Hebei Medical University, Shijiazhuang, China
| | - Fang Guo
- Departments of 1Pharmacology and
| | | | - Rong Zhang
- Toxicology, Hebei Medical University, Shijiazhuang, China
| | - Qing Chen
- Toxicology, Hebei Medical University, Shijiazhuang, China
| | | | - Jian Yin
- Departments of 1Pharmacology and
| | | |
Collapse
|