不同水平干预对心肌细胞ERK核转位及c-fos表达的影响

The impact of different provocations on ERK translocation and c-fos expression in neonatal cultured cardiomyocytes

目的观察血管紧张素(Ang)Ⅱ作用心肌细胞后细胞外信号调节激酶(ERK)活化、核转位情况、c-fos基因表达及在受体和信号ERK水平进行干预的影响.方法采用原代培养的心肌细胞,分别从细胞膜受体和细胞内信号ERK层面进行干预,用细胞免疫化学观察磷酸化ERK入核过程,RT-PCR测定c-fos基因表达量.结果 AngⅡ刺激心肌细胞可见胞核内出现磷酸化ERK染色,Valsartan(10-5 mol/L)、PD98059(5×10-5mol/L)可阻断AngⅡ引起的ERK活化、入核过程,而CGP42112A(10-5mol/L )则无阻断作用;AngⅡ可促进心肌细胞c-fos mRNA表达,在30～60 min达高峰,Valsartan 、PD98059均可抑制该作用,CGP42112A对该作用无明显影响.结论 AngⅡ可磷酸化胞质ERK,并使其发生转位入核,ERK的跨核转运可能是AngⅡ诱导c-fos原癌基因表达的前提.

Objective To study the nuclear translocation of extracelluar signal regulated kinase (ERK) and expression of c-fos mRNA under stimulation of AngⅡ as well as the influence on the nuclear translocation of ERK with different interferences in neonatal cultured cardiomyocytes. Methods ERK in the cytoplasm or nucleus was observed by immunocytochemistry using specific antibody and the expression of c-fos was evaluated with RT-PCR technique. Results AngⅡ(10 -6mol/L) had the effect in promoting activation of ERK and then appeared in nucleus rapidly. The translocation process of ERK induced by AngⅡ was blocked distinctly by Valsartan(10 -5mol/L ) and PD98059(5×10 -5mol/L),but not by CGP42112A(10 -5mol/L ).It was also found that Valsartan and PD98059 could inhibit the expression of c-fos in that process. Conclusion The nuclear translocation of ERK might be a precondition for the inducement of c-fos expression.