心肌营养素-1对三个主要心肌转录因子转录表达的选择性的研究

Effect of cardiotrophin-1 on transcriptional expression of three main transcriptional factors

目的研究心肌营养素-1(cardiotrophin-1,CT-1)对三大主要心肌转录因子的选择性作用,在转录因子水平探讨CT-1肥大刺激作用的特殊机制。方法应用半定量RT-PCR及免疫组化技术,鉴定CT-1对心肌细胞形态学影响。测定CT-1对大鼠心肌细胞GATA4、MEF2以及NKX2-5基因转录的时间、剂量依赖影响。结果GATA4与NKX2-5的表达均与CT-1具有时间、剂量依赖关系,而CT-1则未对MEF2的表达产生影响。从作用时间上看,NKX2-5的表达在1×10-10mol/L的CT-1刺激1h时即开始明显增加,而GATA4的表达则在3h时显著性增加,NKX2-5的表达增强的时间较GATA4略早。结论CT-1以时间和剂量依赖性的方式上调大鼠心肌细胞GATA4及NKX2-5mRNA表达,对大鼠心肌细胞MEF2mRNA表达没有明显影响。

AIM To study the selective effects and mechanism of cardiotrophin-1 （ CT-1 ） on the three main cardiac transcriptional factors. METHODS Using semi-quantity RT-PCR and immunohistochemistry method, we identified the morphologic effects of CT-1 on cardicmyocytes. RESULTS Time and dose-dependent relationship was found between CT-1 and GATA4 or NKX2-5. CT-1 did not affect the expression of MEF2 mRNA. The expression of NKX2-5 mRNA significantly increased lh after treatment with 1 × 10^-10 mol/L CT-1, while significant increase were found in GATA4 mRNA only 3h after the treatment with the same concentration of CT-1. The increasing of NKX2-5 was earlier than that of GA- TA4. CONCLUSION CT-1 promotes the expression of GATA4 or NKX2-5 mRNA in a time and dosedependent manner but has no obvious effect on mRNA expression of MEF2.