甘草皂苷抑制血管平滑肌细胞增殖与β-catenin信号通路的关系

Glycyrrhizin Attenuates Vascular Smooth Muscle Cells Proliferation by Inhibiting the Nuclear Translocation of β-catenin

目的:探讨甘草皂苷对血管平滑肌细胞(VSMCs)增殖的作用及内在分子机制,同时在体研究甘草皂苷对大鼠颈总动脉球囊损伤后内膜新生的影响。方法:采用10μmol/L和50μmol/L甘草皂苷干预体外培养的胸主动脉VSMCs,用活细胞计数法评价VSMCs增殖能力,Western Blotting方法检测VSMCs胞核和胞浆中的信号蛋白β-catenin表达,实时定量RT-PCR检测β-catenin下游靶基因cyclinD1的mRNA水平。构建大鼠颈总动脉球囊损伤模型后,应用甘草皂苷干预28天,观察大鼠颈总动脉内膜增生情况。结果:与FBS刺激组相比,甘草皂苷显著抑制胞核内β-catenin水平(1.80±0.61vs 0.82±0.15,P<0.05)和下游cyclinD1的mRNA表达(2.20±0.05vs 0.63±0.07,P<0.05),进而抑制VSMCs增殖(1.93±0.17vs 1.47±0.21,P<0.05);且在大鼠颈总动脉球囊损伤28天后,较对照组内膜新生显著减少(2.28±0.26vs 1.56±0.23,P<0.05)。结论:甘草皂苷通过调控β-catenin/cyclinD1信号通路,抑制动脉内膜损伤后VSMCs增殖,可能具有防治冠脉内支架术或球囊成型术后再狭窄作用。

Objective:To explore the effect of glycyrrhizin on vascular smooth muscle cells(VSMCs)proliferation and the influnence of glycyrrhizin on neointimal formation in vivo.Method:VSMCs were cultured with 10μmol/L glycyrrhizin,the cell prolifereation was measured by live cell count.β-catenia protein expression in VSMCs nudeus and aytoplasm was detected by western blotting,β-catenin and cyclinD1 mRNA expression were detected by RT-PCR.In addition,the model of rat carotid artety balloon injary was set,the neointimal formation was observed after 28days treatment with glycyrrhizin.Results:Compared to FBS group,glycyrrhizin could significantly inhibitβ-cotenin level in nucleus(1.80±0.61vs 0. 82±0.15,P<0.05)and the down-stream target level of cyclinD1(2.20± 0.05vs 0.63±0.07,P<0.05).In addition,glycyrrhizin could inhibit the proliferation of VSMCs in vitro(1.93±0.17vs 1.47±0.21,P<0.05). Furthermore,glycyrrhizin could reduce the ratio of intimal to medial area at 28th day in vivo(2.28±0.26vs 1.56±0.23,P<0.05).Conclusion: Our study highlights the potential clinical value of glycyrrhizin on treatment of occlusive vascular diseases,and reveals that β-catenin/cyclinD1 signaling is involved in the regulation of glycyrrhizin on neointimal formation.