中文摘要：

目的观察血管紧张素Ⅱ（angiotensinⅡ,AngⅡ）诱导H9c2心肌细胞肥大过程中细胞周期调控因子mRNA的时相性表达。方法 AngⅡ（1.0μmol·L~（-1））刺激H9c2细胞,分别于0 min、5 min、10 min、30 min、1 h、2 h、3 h、6 h、12h、24 h、48 h,罗丹明标记鬼笔环肽染色并检测细胞面积;Real-time PCR法检测细胞周期蛋白（cyclin）B、D、E,细胞周期蛋白依赖性激酶（cyclin-dependent kinases,CDK）1、2、4、6,以及CDK抑制因子p21 mRNA的表达变化情况。结果随着AngⅡ刺激时间的延长,H9c2细胞面积逐渐增大;细胞周期调节因子均于刺激后出现短暂反应性表达增加,周期蛋白E与CDK2、CDK4 mRNA在5 min时达到峰值,周期蛋白D mRNA在10 min时达到峰值,随后一直呈减少趋势;CDK6与周期蛋白B mRNA表达出现双峰现象,分别于5 min和30min达第一峰,随后表达减少,于2 h达最低点,接着又表达增加,于12 h达第二峰。p21 mRNA表达量于30 min达峰值,随后逐步减少,3 h时表达最低,之后又缓慢增加。结论AngⅡ诱导H9c2心肌细胞肥大发生的病理过程与细胞周期调控因子的震荡性表达相关,各因子共同促进细胞肥大反应。

英文摘要：

Aim To observe the mRNA expressions of cell cycle regulators at different time points during the hypertrophic process of H9c2 rat cardiomyoctes induced by angiotensin Ⅱ stimulation. Methods H9c2 myocytes were stimulated with 1. 0 μmol · L~（-1）angiotensin Ⅱ（ Ang Ⅱ） for scheduled time. Cells were stained by Rhodamine labeled phalloidin and the cell area was measured by Image J software. mRNA expression levels of cyclin B,D,E,cyclin dependent kinase（ CDK） 1,2,4,6,and CDK inhibitor p21 were determined by real-time PCR at different time points（ 0,5,10,30 min,and 1,2,3,6,12,24,48 h）. Results H9c2 cell size increased soon after stimulation of Ang Ⅱ; mRNA expressions of cyclin E,CDK4 and CDK2 all reached the peak at 5min after stimulation of Ang Ⅱ; mRNA expression of cyclin D was increased dramatically at 10 min,followed by a decrease trend.However,the mRNA expression of cyclin B and CDK6 both showed two peaks,a p21 mRNA level was up to the peak at 30 min,and the expression was lowest at3 h. Although its expression increased gradually after3 h,p21 mRNA remained low level. Conclusion mRNA expression levels of the cell cycle regulators fluctuate and jointly facilitate the hypertrophic process of cardiomyocytes.