过表达MicroRNA-199a促进TNFα诱导的脂肪细胞凋亡

Over-expression of Micro RNA-199a Intensifies the TNFα-induced Apoptosis of Adipocytes

旨为探明micro RNA-199a(mi R-199a)对脂肪细胞凋亡的影响及核转录因子κB(nuclear factorκB,NF-κB)在其中的作用。培养3T3-L1脂肪细胞,使用肿瘤坏死因子α(tumor necrosis factorα,TNFα)诱导细胞凋亡。在此基础上分别使用NF-κB阻断剂PDTC和mi R-199a mimic处理细胞,判断过表达mi R-199a对TNFα诱导的脂肪细胞凋亡的影响及NF-κB在其中的作用。使用流式细胞仪分析细胞凋亡率,试剂盒检测Caspase3/7酶活,双荧光素酶报告系统检测NF-κB活性,q RT-PCR检测mi R-199a的表达水平,Western blotting检测NF-κB相关蛋白变化。结果显示,TNFα可以诱导分化的脂肪细胞凋亡并同时激活NF-κB,激活的NF-κB在TNFα诱导的脂肪细胞凋亡中发挥负调控作用。在脂肪细胞过表达mi R-199a明显抑制NF-κB的激活进而显著促进TNFα诱导的凋亡。mi R-199a通过调控NF-κB活性参与TNFα诱导的脂肪细胞凋亡。

The aim of this study is to explore the effects of MieroRNA-199a （ miR-199a ） on adipocytes apoptosis and the role of nuclear factor κB （ NF-κB ） . Tumor necrosis factor α （ TNFα ） was used to induce the apoptosis of cultured 3T3-L1 adipocytes. Based on this work, adding PDTC of NF-κB blocker and miR-199a mimic, the effect of overexpression of miR-199a on TNFα-induced apoptosis and the role of NF- κB in it were determined. The flow cytometry was used to analyze the cell apoptosis, kit Caspase3/7 to detect the enzymatic activities, dual luciferase reporter assay to detect the activity of NF-κB, qRT-PCR to detect the expression of miR-199a, and Western blotting to detect the changes of relevant proteins. As results showed, TNFα induced the apoptosis of differentiated adipocytes, concurrently activated NF-κB. The activated NF-κB played a negative regulator role in the apoptosis of adipocytes mediated by TNFα. Over-expressed miR-199a significantly suppressed the activation of NF-κB, and then remarkably promoted the apoptosis induced by TNFα. Conclusively, miR-199a involves in the TNFα-indnced apoptosis of adipocytes through regulating NF-κB activation.