miR-132-3p调控TLR4对颞下颌关节骨关节炎模型大鼠软骨细胞损伤的影响OA

Objective:To investigate the effect of miR-132-3p regulating Toll-like receptor 4(TLR4)on chondrocyte injury in a rat model of temporomandibular osteoarthritis(TMJOA).Methods:Rats were ran-domly divided into a sham operation group and a model group.HE staining was used to detect pathological changes of TMJ condylar cartilage tissue.The expressions of miR-132-3p and TLR4 mRNA in TMJ cartilage tissue were detected by qRT-PCR.Two rats were selected from each of the sham operation group and the model group,and right-sided TMJ chondrocytes were isolated.The TMJ chondrocytes isolated from the sham operation group were designated as the control group,whilst those from the model group were divided into the TMJOA group,the mimic NC group,the miR-132-3p mimic group,miR-132-3p mimic+OE-NC group,and miR-132-3p mimic+OE-TLR4 group.qRT-PCR was used to detect the expression of miR-132-3p and TLR4 mRNA in cells;CCK-8 and flow cytometry were used to assess cell viability and apoptosis,respec-tively;ELISA was used to measure levels of interleukin(IL)-10,IL-6 and tumour necrosis factor-α(TNF-α);Western blot was used to detect TLR4,aggrecan and collagen II in TMJ chondrocytes;and the targeting relationship was verified.Results:Compared with the sham operation group,the TMJ condylar cartilage tissue of rats in the model group showed inflammatory cell infiltration,disordered chondrocyte arrangement,thinner cartilage layer thickness,decreased miR-132-3p expression in TMJ cartilage tissue,and increased TLR4 mRNA expression(P<0.05).Compared with the control group,the expression of miR-132-3p,cell viabili-ty,IL-10 level,Aggrecan and Collagen II proteins in TMJ chondrocytes of the TMJOA group decreased,while the expression of TLR4 mRNA and protein,apoptosis rate,IL-6 and TNF-α levels increased(P<0.05).Compared with the TMJOA group and the mimic NC group,the expression of miR-132-3p,cell viabili-ty,IL-10 level,Aggrecan and Collagen II proteins in TMJ chondrocytes of the miR-132-3p mimic group in-creased.The expressions of TLR4 mRNA and protein,the apoptosis rate,and the levels of IL-6 and TNF-α decreased(P<0.05).OE-TLR4 weakened the promoting effect of overexpression of miR-132-3p on the proliferation of TMJ chondrocytes in TMJOA rats,as well as the inhibitory effects on apoptosis,ECM degrada-tion and inflammation.miR-132-3p targets and regulates TLR4.Conclusion:Overexpression of miR-132-3p may promote the proliferation of TMJ chondrocytes in TMJOA rats by targeting and inhibiting TLR4,and in-hibit apoptosis,ECM degradation,and inflammation.