Abstract: Objective To investigate the effects of SUMOylation on IκB/NF-κB signaling in cultured rat mesangial cells under high glucose. Methods Cultured HBZY-1 rat GMCs were divided into normal glucose group, high glucose groups, and osmotic control group. Interaction between SUMO1,SUMO2/3 and IκBα was detected by co-immunoprecipitation. The expression of IκBα,NF-κB p65 was measured by Western blot. Results The interaction between SUMO2/3 and IκBα in high glucose groups was significantly decreased as compared with normal glucose group（P﹤0.05）. Compared with normal glucose, IκBα in high glucose groups was degradated by ubiquitin-proteasome pathway in a dose and time-dependent manner（P﹤0.05）, but the expression of NF-κB p65 was increased （P﹤0.05）. Conclusion High glucose obviously changes the interaction between SUMO2/3 and IκBα in cultured rat GMCs, which may be involved in the activation of NF-κB by specifically impacting SUMOylation of IκBα.

Key words: Sumoylation, IκBα, NF-κB, Diabetic nephropathy