LncRNA MIRT1靶向JNK调控血管平滑肌细胞增殖、迁移及其分子机制

Proliferation and migration of vascular smooth muscle cells regulated by lncRNA-MIRT1 targeting JNK and its molecular mechanism

目的探讨长链非编码RNA(lncRNA)心肌梗死相关转录因子1(MIRT1)对血管平滑肌细胞增殖、迁移的影响及其分子机制。方法购置ApoE-/-小鼠,制备动脉粥样硬化(AS)模型,分为对照组和模型组。购置人主动脉血管平滑肌细胞(HA-VSMC),根据转染情况分为si-Con组和si-MIRT1组。采用实时荧光定量聚合酶链反应检测小鼠主动脉及HA-VSMC细胞MIRT1表达。观察MIRT1基因敲除对HA-VSMC细胞增殖、迁移、凋亡的影响,采用免疫蛋白印迹法检测细胞凋亡蛋白、炎症因子和JNK信号通路蛋白表达。结果模型组小鼠主动脉MIRT1表达水平显著高于对照组(P<0.05);si-MIRT1组细胞MIRT1表达水平显著低于si-Con组(P<0.05);与si-Con组比较,si-MIRT1组细胞MIRT1表达水平、增殖率、迁移率、凋亡率、Bax蛋白表达水平、Bax/Bcl-2比值、白细胞介素-1β(IL-1β)、白细胞介素-6(IL-6)、肿瘤坏死因子-α(TNF-α)表达水平、JNK和p-JNK水平显著降低,Bcl-2蛋白表达水平显著升高(P<0.05)。结论MIRT1在AS中表达上调,沉默lncRNA MIRT1可抑制HA-VSMC细胞增殖和迁移,减少细胞凋亡,其机制可能与抑制JNK通路信号传导,减少炎性细胞浸润有关。

Objective To investigate the influence of long noncoding RNA(lncRNA)-myocardial infarction-related transcription factor 1(MIRT1)targeting JNK on the proliferation and migration of vascular smooth muscle cells(VSMC)and its molecular mechanism.Methods The model of atherosclerosis(AS)was established in ApoE-/-mice,and all mice were divided into control group and model group.Human aortic VSMC(HA-VSMC)were purchased and divided,according to transfection status,into si-Con group and si-MIRT1 group.MIRT1 expression was detected by using real-time fluorescence quantitative polymerase chain reaction(qRT-PCR)in mouse aorta and HA-VSMC.The influence of MIRT1 gene knockout on the proliferation,migration and apoptosis of HA-VSMC was observed.The expressions of apoptosis proteins,inflammatory factors and JNK signaling pathway-related proteins were detected by using Western blotting assay.Results The expression level of MIRT1 was significantly higher in model group than that in control group(P<0.05),and significantly lower in si-MIRT1 group than that in si-Con group(P<0.05).Compared with si-Con group,the expression level of MIRT1,proliferation rate,migration rate and apoptosis rate of HA-VSMC,expression level of Bax,ratio of Bax to Bcl-2(Bax/Bcl-2),expression levels of IL-1β,IL-6 and TNF-α,and levels of JNK and p-JNK decreased significantly,and expression level of Bcl-2 increased significantly in si-MIRT1 group(P<0.05).Conclusion The expression of MIRT1 is up-regulated in AS.The silence lncRNA-MIRT1 can inhibit the proliferation and migration of HA-VSMC and reduce apoptosis.The mechanism may be related to the inhibition of JNK signaling pathway transduction and reduction of inflammatory cell infiltration.