miRNA-195在腹主动脉瘤血管平滑肌细胞中作用机制探讨

The mechanism of miRNA-195 in vascular smooth muscle cells of abdominal aortic aneurysm

目的探讨miRNA-195在大鼠腹主动脉瘤中表达及对血管平滑肌细胞的作用。方法建立大鼠腹主动脉瘤模型,实时荧光定量PCR检测miRNA-195在腹主动脉瘤组织中的表达量;血管平滑肌细胞中转染miRNA抑制物,用CCK-8试剂盒检测细胞增殖变化,流式细胞仪技术检测细胞凋亡率,蛋白印迹法检测MMP-2、MMP-9和OPN蛋白表达。结果miRNA-195在大鼠腹主动脉瘤组织中呈高表达;血管平滑肌细胞中转染miRNA-195抑制物后,转染组细胞的增殖能力在48 h、72 h和96 h比对照组提高40.5%(P<0.05)、39.7%(P<0.01)、36.1%(P<0.001),且转染组细胞凋亡率比对照组降低35.6%(P<0.001),MMP-2蛋白、MMP-9蛋白和OPN蛋白在转染组中表达量分别比对照组降低45.4%、36.8%和48.8%,差异均有统计学意义(P<0.05)。结论miRNA-195表达升高导致血管平滑肌细胞数量减少,并可能通过上调MMP-2和MMP-9蛋白表达致细胞外基质发生降解,从而促进腹主动脉瘤的形成和发展。

Objective To explore the expression of miRNA-195 in rat abdominal aortic aneurysm and its effect on vascular smooth muscle cells.Methods A rat abdominal aortic aneurysm model was established,and real-time fluorescence quantitative PCR was used to detect the expression of miRNA-195 in abdominal aortic aneurysm tissue.The vascular smooth muscle cells were transfected with miRNA inhibitors,and CCK-8 kit was used to detect cell proliferation changes.Flow cytometry technology was used to detect cell apoptosis rate,and Western blotting method was used to detect MMP-2,MMP-9 and OPN protein expression.Results MiRNA-195 was highly expressed in rat abdominal aortic aneurysm tissue.After transfection of miRNA-195 inhibitor into vascular smooth muscle cells,the proliferation ability of cells in the transfected group was increased by 40.5%compared with the control group at 48 h(P<0.05),72 h[39.7%(P<0.01)]and 96 h[36.1%(P<0.001)].and the cell apoptosis rate in the transfection group was 35.6%lower than that in the control group(P<0.001).The expression levels of MMP-2 protein,MMP-9 protein and OPN proteins in the transfection group were reduced by 45.4%,36.8%and 48.8%respectively compared with the control group,and the differences were statistically significant(P<0.05).Conclusion Increased expression of miRNA-195 leads to a reduction in the number of vascular smooth muscle cells and may lead to the degradation of extracellular matrix by up-regulating the expression of MMP-2 and MMP-9 proteins,thereby promoting the formation and development of abdominal aortic aneurysms.