氧化低密度脂蛋白对大鼠血管平滑肌细胞弗林蛋白酶表达的影响

Effects of ox-LDL on furin expression in cultured ratvascular smooth muscle cells

目的:研究氧化低密度脂蛋白(ox-LDL)对体外培养的大鼠血管平滑肌细胞(VSMCs)弗林蛋白酶(furin)表达的影响,初步探讨ox-LDL影响活性转化生长因子-β(TGF-β)产生的作用机制。方法:本实验分为5组:对照组,ox-LDL 20、40、80、100mg/L组;体外培养大鼠VSMCs,按实验方案给予不同浓度ox-LDL作用24h后,采用实时定量PCR和western blot方法检测各组细胞furin的mRNA及蛋白表达量,用荧光分析法检测各组furin的活性。结果:与对照组比较,ox-LDL 20、40mg/L组的furin蛋白表达量升高[(0.628±0.013),(0.991±0.009),(1.078±0.033),P<0.01],而ox-LDL 80、100mg/L组furin的蛋白表达量下降[(0.584±0.017),(0.559±0.021),P<0.05]。结论:低浓度ox-LDL(20、40mg/L)促进大鼠VSMCs中furin的表达,而高浓度ox-LDL(80、100mg/L)则抑制furin的表达;ox-LDL可能通过furin途径影响活性TGF-β的产生,从而影响斑块的稳定性。

Objective：To investigate the expression of furin regulated by oxidized low-density lipoprotein（ox-LDL） in cultured rat vascular smooth muscle cells（VSMCs）,and to illustrate the effects of ox-LDL on transforming growth factor-β（TGF-β） activation. Method：VSMCs were cultured in DMEM and then stimulated with ox-LDL as indicated.Furin mRNA and protein expression were examined by RT-PCR and western blot.Furin activity was tested by fluorescence analysis method. Result：Compared with control group,the protein（delete） expression of furin in 20 and 40 mg/L ox-LDL groups were higher [（0.628±0.013）,（0.991±0.009）,（1.078±0.033）,P〈0.01],and in the other two ox-LDL groups（80,100 mg/L） were lower [（0.584±0.017）,（0.559±0.021）,P〈0.05]. Conclusion：Low concentrations of ox-LDL（20,40 mg/L） upregulate furin expression in cultured VSMCs,while the high concentrations（80,100 mg/L） downregulate.Ox-LDL may affect plaque stability through furin-mediated TGF-β activation.