胃促生长素对人主动脉平滑肌细胞增殖及线粒体融合蛋白2表达的影响

Effect of ghrelin on proliferation and mitofusin-2 expression of human aortic smooth muscle cells

目的通过体外培养人主动脉平滑肌细胞(HASMCs),研究胃促生长素(ghrelin)对血管平滑肌细胞(VSMC)增殖及线粒体融合蛋白2(Mfn-2)表达的影响。方法体外培养HASMCs,第4~6代细胞用于试验。给予不同浓度(10^(-9)、10^(-8)、10^(-7)、10^(-6)、10^(-5) mol/L)的ghrelin或10^(-6) mol/L ghrelin不同时间(0、6、12、18、24h)处理,用四甲基偶氮唑蓝比色(MMT)法观察其对HASMC增殖的影响。RT-PCR,Western blot方法检测不同处理方法对Mfn-2表达的影响。结果 10^(-7)~10^(-5) mol/L的ghrelin可明显抑制HASMC增殖,浓度为10^(-6) mol/L抑制作用最为明显(P<0.01)。ghrelin在6~24h内均能明显抑制HASMC增殖,在24h达最高峰(P<0.01)。10^(-6) mol/L ghrelin能明显上调Mfn-2 mRNA和蛋白的表达(P<0.01)。10^(-6)mol/L ghrelin在18h上调Mfn-2mRNA和蛋白表达的作用最为明显(P<0.01)。结论 ghrelin可能通过上调Mfn-2的表达来抑制HASMC增殖。

Objective To investigate the effects of ghrelin on proliferation of vascular smooth muscle cells （VSMC） and the expression of mitochondrial fusion 2 （Mfn-2） in cultured human aortic smooth muscle cells （HASMCs）. Methods HASMCs were cultured in vitro, treated with different concentrations（10^-9,10^-8,10^-7 , 10^-6 , 10^-5 mol/L）ghrelin or 10^-6 mol/L ghrelin for different time（0,6,12,18,24 h）. Subconfluent HASMCs at passage 4-6 were used in experiments. MTT essay was used to investigate the effect on proliferation of HASMCs. RT-PCR and Western blot were used to analyse the expression of Mfn-2. Results 10^-7 - 10^-5 mol/L ghrelin inhibited the proliferation of HASMCs,and the inhibitory effect of concentration of 10-6 mol/L was the most obvious（P〈0.01）. Ghrelin inhibited the proliferation of HASMCs in 6- 24 h, and it reached the peak at 24 h（P〈0.01）. 10^-6 mol/L ghrelin significantly increased the expression of Mfn-2 mRNA and protein（P〈0.01）. The up-regulation of 10^-6 mol/L ghrelin on Mfn-2 mRNA and protein expression reached the peak at 18 h（P〈0.01）. Conclusion Ghrelin might inhibit the proliferation of HASMC by up-regulating the expression of Mfn-2.