心肌营养素-1对心肌转录因子GATA4表达影响的实验研究  

Effect of cardiotrophin-1 on cardiac transcription factor GATA4 expression in rat cardiomyocytes

作　　者：赵赫男[1] 王彦[2] 李深[1] 姜妙娜[1] 汤建禾[3] 贾玉杰[1] 

机构地区：[1]大连医科大学病理生理教研室,116027 [2]大连医科大学第二临床学院实验中心 [3]大连医科大学学报编辑部

出　　处：《中华心血管病杂志》2006年第8期733-738,共6页Chinese Journal of Cardiology

摘　　要：目的研究心肌营养素-1(cardiotrophin-1,CT-1)对心肌转录因子GATA4的表达影响以及其3条主要信号通路,即JAK-信号传导子和转录激活子3(JAK-STST3)通路、细胞外信号调节激酶1/2(ERK1/2)及磷脂酰肌醇3-激酶(PI3-K)在其中发挥的作用。方法应用半定量RT-PCR及EMSA技术,测定CT-1对大鼠心肌细胞GATA4 mRNA及结合活性表达的时间、剂量依赖影响。通过单独或联合应用Parthenolide(STAT3通路阻断剂)、U-0126(ERK通路阻断剂)及LY-294002(PI3-K通路阻断剂),分析GATA4两指标的表达变化阐述3条信号通路在该过程中发挥的作用。结果时间依赖实验,0.1nmol/L的CT-1刺激后,GATA4 mRNA表达在3h出现显著性增加,刺激6h以后均表现为极显著性差异(P<0.01),6h以后各组间差异无统计学意义。GATA4结合活性在刺激10min后开始增加,到60 min时达到最大值,180 min下降至刺激前水平。剂量依赖实验,GATA4 mRNA表达在CT-1的刺激浓度为0.01 nmol/L以上时各组均表现为极显著性增加(P<0.01)。GATA4结合活性在0.01nmol/L时,灰度值较无刺激组略增高,0.1 nmol/L时灰度值达到最高值,以后强度略减弱并维持该水平。通路实验结果显示,U-0126可以增加CT-1刺激后GATA4 mRNA(P<0.05)的表达和结合活性的增加,Parthenolide可以显著降低GATA4 mRNA(P<0.01)和结合活性的表达,应用LY- 294002后GATA4相关指标与对照组差异无统计学意义。此外,Parthenolide可以抑制由U-0126引起的GATA4 mRNA表达的增加(P<0.01)及结合活性的增高。结论CT-1可引起大鼠心肌转录因子GATA4转录及结合活性的表达增强。STAT3通路在CT-1刺激GATA4表达中起关键性作用,ERK通路则通过增强STAT3通路来促进CT-1对GATA4的表达影响,P13-K通路在两者的相关关系中不发挥作用。Objective To investigate the effect of cardiotrophin-1 （CT-1） on the GATA4 expression and related signaling pathways （ JAK-STAT3, ERK1/2 and PI3-K ） in rat cardiomyocytes. Methods Using semi-quantitative RT-PCR and EMSA, we measured the dose and time dependent effects of CT-1 on GATA4 mRNA and binding activity in cultured rat cardiomyocytes. Parthenolide （a STAT inhibitor） , U-0126 （an ERK inhibitor） and LY-294002 （a PI3-K inhibitor）alone or in combination were added to the culture medium to assess the role of above signaling pathways in CT-1 mediated effects. Results GATA4 mRNA expression significantly increased at 3 h pest 0. 1 nmol/L CT-1 exposure, peaked at 6 h and remained high till 24 h post exposure. The GATA4 binding activity began to increase at 10 min and peaked at 60 min and returned to baseline level 180 min. Six hours post CT-1 （0. 01 nmol/L, 0. 1 nmol/L, 1 nmol/L） exposure, the GATA4 mRNA expression increased in a dose-dependent manner. The GATA4 binding activity peaked with 0. 1 nmol/L CT-1 and higher dose did not further increase the binding activity. U-0126 increased the GATA4 mRNA expression and enhanced the GATA4 binding activity and these effects could be partially attenuated with addition of Parthenolide. Parthenolide also prevented the increase of GATA4 mRNA and binding activity induced by CT-1. LY-294002 had no effects GATA4 mRNA and binding activity. Conclusion CT-1 increases the GATA4 mRNA expression and binding activity in rat cardiomyoeytes via STAT3/ERK1/2 pathways and these effects are independent of PI3-K pathway.

关 键 词：心肌 转录因子 信号传导 心肌营养素1 

分 类 号：R541[医药卫生—心血管疾病]