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[The up-regulation of hypoxia inducible factor-1α induced by hypoxic postconditioning protected Heart-derived H9c2 Cells against Hypoxia/Reoxygenation.] [Article in Chinese]

ZHAO Huan-Xin, LI Xiao-Yu, YAO Hong, WU Ye, YANG Rong, ZHAO Rong-Rui, LIU Hui-Rong

Department of Physiology, Shanxi University of Traditional Chinese Medicine , Taiyuan 030024, China； Department of Physiology, Shanxi Medical University, Taiyuan 030001, China； School of Basic Medical Sciences, and Cardiovascular Research Institute, Capital Medical University, Beijing 100069, China

Abstract

This study was to explore the effects of hypoxic postconditioning (PostC) on heart-derived H9c2 cells injury induced by hypoxia/reoxygenation (H/R) and the expression of hypoxia inducible factor-1α (HIF-1α), and to analyze the relationship between them. Cultured H9c2 cardiac muscle cells were used to encounter 3 h hypoxia and 2 h reoxygenation to simulate ischemia and reperfusion, or underwent 3 cycles of 5 min reoxygenation and 5 min hypoxia preceding the long reoxygenation to simulate ischemic postconditioning. Cell viability, lactic dehydrogenase (LDH) activity, and caspase-3 activity were detected respectively to image the cell injury induced by H/R. The level of HIF-1α mRNA was measured by real time-PCR. Western blot was used to determine HIF-1α protein level. The results showed that postconditioning significantly increased H9c2 cell viability, reduced the activity of LDH and caspase-3. Simultaneously, postconditioning up-regulated HIF-1α protein level. Moreover, after DMOG, an inhibitor of proline hydroxylase (PHD) which is targeted to HIF-1αdegradation, was used to stabilize HIF-1α protein level, the reduction of H9c2 cells injury was comparable to that by postconditioning. There was a significant linear positive relationship between HIF-1α protein level and cell viability(r=0.743, P<0.01). After being infected with siRNA to silence HIF-1α gene, the cardioprotective effects of postconditioning was significantly weakened. These data suggested that up-regulation of HIF-1α induced by postconditioning play an important role in the cardioprotection of postconditioning.

Key words: hypoxic postconditioning; hypoxia inducible factor-1α; hypoxia/reoxygenation

Received: 2012-12-21　　Accepted: 2013-04-23

Corresponding author: 赵焕新　　E-mail: zhhx5@yahoo.com.cn

Citing This Article：

ZHAO Huan-Xin, LI Xiao-Yu, YAO Hong, WU Ye, YANG Rong, ZHAO Rong-Rui, LIU Hui-Rong. [The up-regulation of hypoxia inducible factor-1α induced by hypoxic postconditioning protected Heart-derived H9c2 Cells against Hypoxia/Reoxygenation.] [Article in Chinese]. Acta Physiol Sin 2013; 65 (3): 293-300 (in Chinese with English abstract).