Activation Of NLRP3/caspase-1/IL-1? Axis And Effect Of Resveratrol In Cartilage Of Obesity-related Osteoarthritis

Objective:To investigate the activation of NLRP3/caspase-1/IL-1?axis in articular cartilage of high-fat-diet induced obesity-related osteoarthritis?OA?mice and the effect of resveratrol?RES?on the axis and provide theoretical basis for nutritional prevention of obesity-related OA.Methods:SW1353 chondrosarcoma cell line was purchased from the Cell Resource Center of Shanghai Academy of Sociology,Chinese Academy of Sciences.The cells were cultured in an incubator at 37°C,5%CO₂ and saturated humidity using DMEM complete medium,and treated with IL-1?or RES,groups:DMSO group?containing2‰DMSO?,IL-1?group?10ng/mL?,IL-1??10ng/mL?+RES?50?mol/L?group.C57BL/6 mice were provided by Animal Experimental Center of China Medical University,and high-fat feeding was also gavaged with RES?45 mg/kg/d?suspension dissolved in 0.5%Carboxymethylcellulose sodium?CMC?,groups:ND group?gavaged with 0.5%CMC?,HFD group?gavaged with 0.5%CMC?,HFD+RES?gavaged with 0.5%CMC+RES?group.The protein expression levels of NLPR3,caspase-1 and IL-1?were detected by Western blot.The degree of joint tissue lesions was evaluated by tissue section staining.The expression of NLRP3,caspase-1 and IL-1?mRNA in mouse articular cartilage was detected by qRT-PCR.The expression level of MMP13,NLPR3,caspase-1 and IL-1?in articular cartilage was detected by immunohistochemical method.Results:1.The expression of NLRP3,caspase-1 and IL-1?protein in IL-1?-treated SW1353cells and the roles of resveratrolCompare with DMSO group,IL-1?could significantly increase the expression of NLRP3,caspase-1 and IL-1?protein?P<0.05?;RES can reduce the expression of NLRP3 inflammasome associated protein compared with the IL-1?group?P<0.01?.2.The changes in body weight,body fat ratio and food intake of mice in each group during the experimentAt the end of the experiment period,the body weight and body fat ratio of the mice in the HFD group were higher than those in the ND group?P<0.01?.However,there was no significant difference in body weight and body fat ratio between the HFD+RES group and the HFD group?P>0.05?.There was no significant difference in food intake between the ND group,the HFD group and the HFD+RES group during the experiment?P>0.05?.3.The histological changes of knee joints and the effects of RES in the mice fed with high-fat-dietIn the ND group,Safranin-O staining showed the tidal line clear and intact;and HE staining showed that the chondrocytes were arranged neatly and the matrix staining was normal;the tidal line of the HFD group was shallow or disappeared.The chondrocytes were locally increased or decreased,and the OARSI score was the highest.The difference was statistically significant compared with the other two groups?P<0.05?;the cartilage status of the HFD+RES group was better than that of the HFD group,and the OARSI score was significantly lower?P<0.05?.4.The expression of MMP13 in knee joint cartilage of mice in each groupCompared with the ND group,the expression of MMP13 in the knee cartilage of the HFD group increased,and the difference was statistically significant?P<0.01?;RES could decrease the expression of MMP13?P<0.01?.5.The expression of NLRP3,caspase-1 and IL-1?mRNA and effects of RES in knee joint cartilage of mice fed with high-fat-dietThe expression of IL-1?mRNA in the HFD group was significantly higher than that in the ND group?P<0.01?;after RES treatment,IL-1?mRNA expression decreased significantly?P<0.01?.Although there was no statistical difference in the expression of NLRP3 and caspase-1 mRNA,there was a trend consistent with IL-1?.6.The expression of NLRP3/caspase-1/IL-1?axis related protein in cartilage of mice fed with high-fat diet and the effect of RES6.1 The expression of NLRP3 proteinThe NLRP3 positive particles in the HFD group were significantly increased compared with the ND group,and the distribution was uneven,showing a mass.The positive staining of the RES intervention group was significantly lower than that of the HFD group,and the difference was statistically significant?P<0.01?.6.2 The expression of caspase-1 proteinThe expression of caspase-1 protein in HFD group was higher than that in ND group and HFD+RES group,and the difference in mean optical density was statistically significant?P<0.05?.6.3 The expression of IL-1?proteinThe positive staining of IL-1?protein in HFD cartilage was deep and dense,and the optical density was much higher than that in ND group?P<0.05?.RES treatment could decrease the expression of IL-1?protein?P<0.05?.Conclusions:1.The NLRP3/caspase-1/IL-1?axis may be activated in the IL-?treated SW1353chondrosarcoma cell line,and RES exert an inhibitory effect.2.NLRP3/caspase-1/IL-1?axis was activated in cartilage of HFD-induced obese OA mice;RES can inhibit the activation of the axis and protect the joint.