长链非编码RNA KCNQ1OT1影响脂多糖诱导的血管内皮细胞凋亡及其炎性因子表达的机制

LncRNA KCNQ1OT1 Affects LPS-Induced Apoptosis and Inflammatory Response of Vascular Endothelial Cells:the Underlying Mechanism

该研究探讨了长链非编码RNA KCNQ1OT1对脂多糖(LPS)诱导的血管内皮细胞(VEC)凋亡和炎性因子表达的影响以及其可能机制。通过体外培养VEC,分别转染KCNQ1OT1过表达载体、miR-223抑制剂或共转染KCNQ1OT1过表达载体与miR-223模拟物后,用1.0 mg/mL LPS干预24 h,然后采用RT-qPCR法检测细胞中KCNQ1OT1和miR-223的表达水平,流式细胞仪检测细胞凋亡,Western blot检测细胞中Bcl-2和Bax蛋白表达,ELISA试剂盒检测细胞培养上清中TNF-α、IL-1和IL-6水平。双荧光素酶报告基因实验验证KCNQ1OT1与miR-223的调控关系。结果显示,LPS可抑制VEC中KCNQ1OT1的表达,而促进miR-223表达;上调KCNQ1OT1或下调miR-223后均可降低LPS诱导的VEC凋亡率、Bax蛋白及TNF-α、IL-1和IL-6表达(P<0.05),而促进Bcl-2蛋白表达(P<0.05)。KCNQ1OT1靶向负调控miR-223表达,上调miR-223则逆转上调KCNQ1OT1对LPS诱导的VEC凋亡及炎性因子表达的抑制作用。这表明,上调KCNQ1OT1抑制LPS诱导的VEC凋亡及炎性因子表达,其作用机制可能与靶向负调控miR-223有关,KCNQ1OT1/miR-223轴可能为血管内皮细胞损伤的治疗提供了新靶点。

This study investigated whether lncRNA KCNQ1OT1 acted on LPS-induced VEC(vascular endothelial cell)apoptosis and the expression of pro-inflammatory cytokines,as well as elucidated its action mechanism.VECs were stimulated with 1.0 mg/mL LPS for 24 h following transfection of KCNQ1OT1 overexpression vector and/or miR-223 inhibitor.The expression of KCNQ1OT1 and miR-223 was detected by RT-qPCR.Cell apoptosis was examined with flow cytometry.The protein expression of Bcl-2 and Bax was assayed by Western blot.The level of TNF-α,IL-1 and IL-6 in the supernatant was measured utilizing ELISA kit.The regulatory interaction between KCNQ1OT1 and miR-223 was verified by dual-luciferase reporter assay.The results showed LPS stimulation inhibited KCNQ1OT1 expression and promoted miR-223 expression.KCNQ1OT1 upregulation or miR-223 downregulation decreased LPS-induced VEC apoptosis and the expression of Bax,TNF-α,IL-1 and IL-6(P<0.05),while increased that of Bcl-2(P<0.05).KCNQ1OT1 negatively regulated miR-223 expression,as miR-223 upregulation reversed the inhibitory effect of KCNQ1OT1 upregulation on the apoptosis of VECs and the inflammatory cytokine expression both induced by LPS.These results collectively suggest that KCNQ1OT1 upregulation inhibits LPS-induced VEC apoptosis and inflammatory response.Its action mechanism is possible associated with the negative regulation of miR-223.The KCNQ1OT1/miR-223 axis may serve as a novel target in the treatment of vascular endothelial cell injury.