The Role Of JAK2/STAT3/SOCS3 Signaling Pathway In Resveratrol Anti-obesity-induced-OA Of Mice Induced By High-fat Diet

Objective: To investigate whether leptin resistance exists in articular cartilage of obesity-associated OA,and whether the mechanism of action of resveratrol against obesity-related OA involves SOCS3-regulated JAK2-STAT3 signaling pathway,in order to further elucidate the pathogenesis of OA and the nutrition of OA The experimental basis for prevention and treatment.Methods: 54 SPF male C57BL/6 mice weighing 18-22 g were divided into control group,high-fat group and intervention group.The control group was fed a control diet,and the high fat group and the intervention group were fed a high-fat diet.The control group and the high-fat group were given daily 0.5% sodium carboxymethylcellulose(CMC)solution;the intervention group was given RES suspension(45 mg/kg/d the optimal dose obtained in the previous experiment).The mice were fed and drank freely.The mice were weighed and recorded weekly.After 22 weeks,the body fat ratio was measured by body composition analysis.After anesthesia,the eyeballs of mice were taken for blood collection and centrifugation.The serum leptin level was detected by ELISA.Joints were taken for histopathological examination,polyformaldehyde fixation,EDTANa2 decalcification,routine dehydration and transparency,paraffin embedding,6-micron thickness section,HE staining,Safranine O-staining,Safranine O-fixing green staining for histopathological examination and modified Mankin score.Cartilage RNA was extracted and the levels of MMP-13,leptin,OB-Rb and SOCS3 were determined by q RT-PCR.Cartilage protein was extracted and the expression levels of JAK2(p-JAK2),STAT3(p-STAT3),SOCS3 and OB-Rb were determined by Western blot.SW1353 cells were cultured routinely and treated with leptin and/or RES after passage.The cells were divided into control group,leptin group,leptin + RES group,leptin + RES group + AG490,leptin + AG490,AG490 group.Total cell proteins were collected after 2 and 24 hours of culture.The expression levels of JAK2(p-JAK2),STAT3(p-STAT3),SOCS3 and MMP-13 were detected by Western blot.Results: 1.High-fat diet increased the body weight,body fat and serum leptin level of mice,while RES decreased the serum leptin level.2.HE staining,Safranine O staining and safranine O-fixing green staining detected the progress of OA in mice joints of high-fat group.The improved Mankin score increased.RES intervention could slow down the progress of OA and reduce the increased improved Mankin score.3.In the high-fat group,the leptin JAK2/STAT3 signaling pathway was activated,the expression levels of p-JAK2 and p-STAT3 were increased,and the expression of OB-Rb was increased.RES intervention could inhibit the expression of p-JAK2 and p-STAT3 in the knee cartilage of mice,and the expression of OB-Rb was decreased.4.Leptin treatment increased the expression of p-JAK2,p-STAT3,SOCS3 and MMP-13 in SW1353 cells,while resveratrol intervention decreased the expression of p-JAK2,p-STAT3,SOCS3 and MMP-13.AG490,an inhibitor of p-JAK2,decreased the expression of p-JAK2,MMP-13 and SOCS3 in SW1353 cells,but there was no statistical significance.Conclusion:(1)High-fat diet can induce obesity-related OA in mice,while RES has protective effects.(2)The activation of JAK2/STAT3 signaling pathway is observed in obesity-associated OA induced by high-fat diet,but there is no obvious leptin resistance in articular cartilage.Resveratrol can exert anti-obesity-related OA by decreasing the level of leptin and inhibiting the activation of JAK2/STAT3 signaling pathway in cartilage.(3)The inhibitory effect of RES on the leptin-activated chondrocyte JAK2/STAT3 signaling pathway was not associated with SOCS3.