Objective To investigate the role of TRB3 in the inhibitory effect of fenofibrate against the proliferation of glomerular mesangial cell induced by high glucose. Methods Rat glomerular mesangial cells (MCs) were cultured in the presence of 5.5 mmol/L glucose (normal control), 25 mmol/L glucose (high glucose group), or high glucose along with 10, 50, or 100 μmol/L fenofibrate. Cell counting kit-8 (CCK-8) assay was used to evaluate cell proliferation, and Hoechst 33258 staining was employed to determine chromatin distribution in the MCs. Flow cytometry was performed to analyze the cell cycle changes in different groups. The expressions of TRB3 and P-AKT in different groups were detected using immunocytochemistry and Western blotting. Results High glucose induced obvious proliferation of the MCs (P<0.001), which was significantly inhibited by fenofibrate in a concentration-dependent manner (P<0.001). The MCs exposed to fenofibrate presented with typical apoptotic morphologies and cell cycle arrest at G1/S phase. Low levels of TRB3 expression was detected in the normal control and high glucose groups, whereas in the 3 fenofibrate groups, TRB3 expression increased and P-AKT expression decreased as fenofibrate concentration increased. Conclusion Fenofibrate can promote TRB3 expression in rat MCs. TRB3 causes cell cycle arrest at G1/S phase by inhibiting AKT phosphorylation to result in suppressed proliferation of the MCs.%目的 探讨TRB3在非诺贝特抑制高糖诱导下肾小球系膜细胞增殖中的作用及作用其机制.方法 将细胞分为正常对照组(N,5.5 mmol/L葡萄糖)、高糖组(H,25 mmom/L葡萄糖)、高糖+不同浓度的非诺贝特组(FN,10、50、100 μmol/L).采用CCK-8法检测细胞增殖率,Hoechst33258染色观察细胞凋亡形态学改变,流式细胞术检测细胞周期改变,免疫细胞化学染色观察TRB3表达,Western Blot检测细胞中TRB3、P-AKT蛋白的表达.结果 高糖能够诱导肾小球系膜细胞增殖(P＜0.001);非诺贝特能够抑制肾小球系膜细胞增殖(P＜0.001),且具有浓度依赖性.非诺贝特干预后细胞出现凋亡形态学改变;非诺贝特可以使系膜细胞发生G1/S期阻滞;正常组、高糖组胞浆有少量TRB3蛋白表达,但高糖不能促进TRB3表达增多,随着非诺贝特浓度的增加TRB3表达量增多,P-AKT表达逐渐降低.结论 非诺贝特可以促进TRB3的表达;TRB3可能通过抑制AKt的磷酸化使肾小球系膜细胞发生G1/S期阻滞从而抑制其增殖.
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