缺氧诱导因子(HIF)-1α介导的辛伐他汀抗大鼠心肌细胞凋亡作用

HIF-1α mediates anti-apoptotic effects of simvastatin in neonatal cardiomyocytes

目的:观察原代心肌细胞模拟缺血/再灌注(I/R)对缺氧诱导因子(HIF-1α)表达的影响以及HIF-1α在辛伐他汀心肌细胞保护中的作用。方法:原代培养心肌细胞,采用Western blot检测HIF-1α在心肌细胞中的表达水平,采用HEPES缓冲液在低氧(10 ml/L)条件下培养心肌细胞2 h(模拟缺血组,ISC组),然后以含有100 ml/L新生牛血清的DMEM培养液在常规细胞培养箱中继续培养细胞6 h(缺血/再灌注组,I/R组),辛伐他汀预处理(SIM)组是用2μmol/L辛伐他汀预处理心肌细胞后再进行I/R处理。以这种方法模拟细胞在缺血时缺乏血清、糖和氧供的培养条件,再灌注时恢复血清、糖及正常供氧供的条件。接着,运用表达HIF-1α的腺病毒载体在原代心肌细胞中的过表达HIF-1α,采用Western blot检测PARP降解程度方法检测对照腺病毒(Ad C)组、对照腺病毒感染细胞进行I/R处理(Ad CIR)组、对照腺病毒感染细胞采用2μmol/L辛伐他汀预处理后进行I/R处理(Ad CIRS)组和Ad-HIF-1α感染细胞后采用2μmol/L辛伐他汀预处理后进行I/R处理(Ad HIRS)组心肌细胞的凋亡程度。结果:模拟I/R诱导HIF-1α的表达,原代心肌细胞模拟缺血2 h HIF-1α表达是对照组的(3.4±0.8)倍(P<0.05);而模拟缺血2h/再灌注6 h组HIF-1α表达是对照组的(8.9±1.5)倍(P<0.05)。辛伐他汀抑制I/R诱导的HIF-1α表达增高。采用表达HIF-1α的腺病毒过表达HIF-1α抵消了辛伐他汀抑制PARP蛋白降解产物的作用。结论:证明I/R可以诱导HIF-1α表达升高,而辛伐他汀可以显著抑制HIF-1α表达的升高;辛伐他汀对HIF-1α表达的抑制是其心肌保护作用的机制之一。

AIM： To investigate the effect of mimicked ischemia/reperfusion （I/R） model of primary cultured cardiomyocytes on the expression of HIF-1α and the role of HIF-1α in cardioprotection of simvastatin. METHODS： Primary cultured neonatal cardiomyocytes were used in this study and Western blot was applied to determine the protein expression level. Ischemia was mimicked by culturing cells in HEPES buffered solution and low oxygen circumstance （10 ml/L oxygen）, and reperfusion was mimicked by restoring culture medium and oxygen. RESULTS： HIF-1α expression was induced dramatically by mimicked ischemia and I/R. I/R led to better induction than ischemia alone. Pretreatment with 2 μmol/L simvastatin inhibited HIF-1α induction and overexpression of HIF-1α diminished the apoptosis-inhibiting effects of simvastatin. CONCLUSION： Mimicked I/R induces expression of HIF-1α, which is significantly inhibited by simvastatin pretreatment. Inhibition of HIF-1α contributes to the anti-apoptotic effects of simvastatin.