caveolae对血管平滑肌细胞增殖的影响及可能机制

Effect of caveolae on proliferation in vascular smooth muscle cells

目的观察caveolae对血管平滑肌细胞增殖的影响及可能机制。方法取培养第3代VSMCs培养皿中培养。干扰组细胞加甲基-β-环糊精(methyl-β-cyclodextrin,MβCD)(5 mmol/L,DMEM配置)作用2 h;对照组加入与MβCD等量的DMEM作用2 h后以DMEM冲洗3次后正常培养48 h。采集细胞进行RT-PCR检测Caveolin-1、pSmad2 mRNA表达变化,Western blot法检测Caveolin-1、pSmad2蛋白表达变化,免疫组化检测Caveolin-1、TGF-β受体1(TGF-βR1)在细胞中的表达分布,CCK-8法检测细胞增殖能力。结果 Caveolin-1在MβCD干扰后,基因和蛋白表达水平明显下降(P<0.01),并且以细胞膜和细胞质高表达为主;而Smad2在MβCD干扰后,基因和蛋白表达水平明显上升,与正常对照组相比,差异有统计学意义(P<0.01);并且TβR-1在MβCD干扰后细胞内表达增加。CCK-8检测结果显示,MβCD干扰后,VSMCs增殖被显著抑制(P<0.01)。结论破坏caveolae结构后可以抑制VSMCs的增殖,其可能的机制是caveolae被破坏后,TGF-β/Smad信号通路增强,不能抑制Smad2磷酸化和下游的信号转导,从而达到抑制VSMCs的增殖的作用。

Objective To observe the effect of caveolae on the proliferation of vascular smooth muscle cells （VSMCs）. Methods The third generation of VSMCs were cultured in vitro, and were incubated with methyl-β-cyclodextrin （MI3CD） for 2 h. The VSMCs without any treatment were served as blank control. The mRNA and protein expression levels of Caveolin-1 and pSmad2 in VSMCs were detected by RT-PCR and Western blotting, and the distribution of in Caveolin-1 and pSmad2 in VSMCs was detected by immunohisto- chemistry. The proliferative rate of VSMCs was analyzed with CCK-8 assay. Results Caveolin-1 was highly expressed in cell membrane and nucleus. After MβCD treatment, the mRNA and protein expression levels of Caveolin-1 were significantly lower as compared with the control group （ P 〈 0. 01 ）, while the mRNA and protein expression levels of pSmad2 were significantly higher （ P 〈 0. 01 ） increased in cell nucleus after MβCD liferation of VSMC through enhancing interference. Conclusion Destruction TGF-β/Smad signaling pathway The expression of TGF-βR1 was of caveolae can suppress the pro-