UNASSIGNED: This study focused on the target proteins of OGT-induced O-GlcNAcylation in OA and the specific functional mechanism.
UNASSIGNED: The levels of total O-GlcNAc and OGT were measured in both in vitro and in vivo OA models using western blot. The effects of OGT knockout on OA progression were detected through Safranin O staining, immunohistochemical staining and OARSI score evaluation. The effects of OGT silencing on LPS-induced chondrocyte injury were assessed by performing loss-of function assays. Co-immunoprecipitation (co-IP) was conducted to verify the effect of OGT-induced O-GlcNAcylation on the interaction between NEK7 and NLRP3. The role of OGT in modulating the O-GlcNAcylation and phosphorylation levels of NEK7 was analysed using western blot.
UNASSIGNED: The OGT-indued O-GlcNAcylation level was increased in both in vitro and in vivo OA models. Knockout of OGT mitigated OA progression in model mice. Additionally, silencing of OGT suppressed LPS-induced chondrocyte pyroptosis. Moreover, silencing of OGT inhibited the O-GlcNAcylation and enhanced the phosphorylation of NEK7 at S260 site, thereby blocking the binding of NEK7 with NLRP3.
UNASSIGNED: OGT-induced NEK7 O-GlcNAcylation promotes OA progression by promoting chondrocyte pyroptosis via the suppressing interaction between NEK7 and NLRP3.
■本研究集中于OA中OGT诱导的O-GlcNAcylation的靶蛋白及其特定的功能机制。
使用蛋白质印迹在体外和体内OA模型中测量总O-GlcNAc和OGT的水平。通过SafraninO染色检测OGT基因敲除对OA进展的影响,免疫组化染色和OARSI评分评价。OGT沉默对LPS诱导的软骨细胞损伤的影响通过进行功能丧失测定来评估。进行免疫共沉淀(co-IP)以验证OGT诱导的O-GlcNAcylation对NEK7和NLRP3之间的相互作用的影响。使用蛋白质印迹分析OGT在调节NEK7的O-GlcNAcylation和磷酸化水平中的作用。
■OGT引入的O-GlcNAcylation水平在体外和体内OA模型中均增加。OGT的基因敲除减轻了模型小鼠中的OA进展。此外,OGT的沉默抑制了LPS诱导的软骨细胞焦亡。此外,OGT的沉默抑制了O-GlcNAcylation并增强了NEK7在S260位点的磷酸化,从而阻断NEK7与NLRP3的结合。
■OGT诱导的NEK7O-GlcNAcylation通过抑制NEK7和NLRP3之间的相互作用促进软骨细胞的焦亡促进OA进展。