细胞内钙调控对心肌成纤维细胞增殖的作用

目的:探讨不同来源的细胞内Ca2+(Ca2+]i)对心肌成纤维细胞(fibroblasts,PBs)丝裂素活化蛋白激酶(MAPK)介导的增殖反应的作用。方法:以培养的大鼠FBs为模型,用血管紧张素Ⅱ(AngⅡ)刺激FBs细胞外Ca2+跨膜内流、三磷酸肌醇(IP3)刺激胞内Ca2+释放,应用钙荧光指剂Fura-2/AM动态观测心肌细胞ca2+]i浓度,γ-32P-ATP掺入法和免疫印迹(westen blot)测MAPK活性及蛋白含量,氚-亮氨酸(3H-Leu)、氚-胸腺嘧定(3H-TdR)掺入量作为FBs增殖的指标。结果:AngⅡ、IP3均能显著增加FBsCa2+]j浓度、MAPK活性及蛋白含量,并提高3H-Leu、3H-TdR掺入量,与对照组FBs相比差异显著,P<0.01。结论:激活Ca2+]i使MAPK活性及含量明显增加而促进FBs的增殖,FBs的增殖与ca2+]i浓度增加有关,与Ca2+]i的来源无关。

EFFECTS OF INTRACELLULAR CALCIUM REGULATION ON PROLIFEARTION OF CARDIAC FIBROBLASTS

Objective: To investigate the effects of the intracellular free calcium(Ca2 + ]i) from different resources on the proliferation of cardiac fibroblasts(FBs) mediated by mitogen activated protein kinase(MAPK). Method: Calcium influx was stimulated by angiotension II(AngeII) and the intracellular calcium stored release did by 1,4,5- inositol trisphosphateClPs) in cultured FBs. Ca2 + ] i concentration was measured with Fura - 2/AM fluorescent technique, MAPK activity did with Y - 32 P- ATP incorporation and MAPK protein expression with western blot, FBs proliferation with H - LeucineC H - Leu)and Thymidine(3H-TdR)incorporation. Result: It was showed that both Anglt and n?3 increased Ca2+ ]i, activity of MAPK and its protein content, as well as promoted 3H - Leu and 3H - TdR incorporation in FBs, which was different significantly from those of the control(p< 0.01). Conclusion: These results indicate that the activated Ca2+ ]i increase the activity and protein content of MAPK that is involved in the proliferation of FBs. The proliferation of FBs is only related to Ca2+ ]i level, but not to its resources.