SUMO化修饰对高糖诱导的大鼠肾系膜细胞IKKγ/NF-κB信号的影响

 目的：探讨小泛素相关修饰物（SUMO）化修饰对高糖诱导的肾系膜细胞IκB激酶γ(IKKγ)/NF-κB信号的影响。方法：体外培养大鼠肾小球系膜细胞，设正常对照组、高糖干预组和渗透压对照组：用免疫印迹和RT-PCR法检测各组细胞SUMO1、SUMO2/3、IKKγ和NF-κB p65的表达；用免疫共沉淀检测SUMO与IKKγ蛋白间的相互作用。结果：高糖呈浓度和时间依赖性上调系膜细胞SUMO和NF-κB p65表达（均P<0.01）。各组细胞IKKγ 的蛋白与mRNA表达差异无统计学意义（均P<0.05）；高糖组SUMO与IKKγ蛋白间的相互作用减弱（均P<0.01）。结论:高糖影响IKKγ 的SUMO化修饰，可能参与了高糖诱导的肾系膜细胞NF-κB信号激活的调控。

Effects of SUMOylation on IKKγ/NF-κB signaling in cultured rat glomerular mesangial cells treated with high glucose

AIM：To investigate the effects of SUMOylation on IκB kinase γ (IKKγ)/NF-κB signaling in cultured rat glomerular mesangial cells (GMCs) treated with high glucose. METHODS：Cultured HBZY-1 rat GMCs were divided into normal glucose group and high glucose groups, and mannitol was used for osmotic control. The expression of SUMO1, SUMO2/3, IKKγ and NF-κB p65 was measured by Western blotting and RT-PCR. Interaction between SUMO and IKKγ was detected by co-immunoprecipitation. RESULTS：Compared with normal glucose group, the expression of SUMO and NF-κB p65 was increased in high glucose groups in a dose- and time-dependent manner. The expression of IKKγ was not changed by high glucose. The SUMOylation of IKKγ in high glucose groups was significantly decreased as compared with normal glucose group. CONCLUSION:High glucose obviously changes the interaction between SUMO and IKKγ in cultured rat mesangial cells, which may be involved in the activation of NF-κB by taking a special influence on the SUMOylation of IKKγ/NF-κB signaling molecules.