The Expression And Significance Of Interleukin-37 In Osteoarthritis

Osteoarthritis(OA),a most common degenerative joint disease,has characterized by cartilage breakdown,the formation of osteophytes at joint margin and generalized aches and pains.It is traditionally considered that the aging,obesity,wear,tear,genetic predisposition and other systemic diseases might relate to the pathogenesis of OA.Many studies have shown that inflammatory cytokines are associated with inflammatory response of OA,such as IL-1β,TNF-α,CXCL8 and MMP3,these are play an important role in the development of OA.While the regulatory cytokines can inhibit the expression and activity of inflammatory cytokines,consequently,releasing the inflammatory reaction of synovial membrane and reducing the pathological process of joint.IL-37,a new member of the IL-1 family,is mainly distributed in the testis,thymus,uterus,a variety of cells can secrete IL-37,such as peripheral blood mononuclear cells,dendritic cells,epithelial cells,etc..In recent years,it has been reported that IL-37 is an inflammatory factor,which can significantly inhibit natural immunity and acquired immunity.It has been reported that IL-37 plays a role in inhibiting inflammation in a variety of immune diseases,such as ischemia reperfusion injury,psoriasis,DSS colitis,obesity.IL-37 can decrease the expression of IL-1β,IL-1α,IL-8 and TNF-α in peripheral blood mononuclear cells in the inflammatory environment.But so far,the relevance of IL-37 in OA remains unknown.In our study,the peripheral blood samples were collected from OA patients and healthy people,we investigated the expression of IL-37,TNF-α,IL-1β,CXCL8,MMP-3,to explore the relationship between IL-37 and OA clinical index or inflammatory mediators,using recombinant IL-37 protein in vitro stimulation of OA in patients with peripheral blood mononuclear cells(PBMCs)and synovial cells test to explore the role of IL-37 in OA.In vitro,Using recombinant IL-37 protein to simulate peripheral blood mononuclear cells and synovial cell with patients of OA,to explore the role of IL-37 in OA.Objective Investigate the expression of IL-37,TNF-,IL-1,CXCL8 and MMP-3 in peripheral blood of OA patients.Investigate the correlation between the expression of IL-37 and the clinical and inflammatory mediators of OA.Investigate whether IL-37 can regulate the expression of inflammatory cytokines in OA.Methods1.Collecting the samples and clinical information.2.RT-PCR detect IL-37 mRNA expression in PBMCs of OA patients and healthy controls.3.ELISA detect serum IL-37 protein level of OA patients and healthy controls4.Analyzing the correlations between serum IL-37 levels with clinical index of OA thought Spearman correlation test..5.RT-PCR detect TNF-α,IL-1β,CXCL8,MMP-3 mRNA expression in PBMCs of OA patients and healthy controls.6.ELISA detect serum TNF-α,IL-1β,CXCL8,MMP-3 protein level of OA patients and healthy controls.7.Construct plasmid which can expression human IL-37,the expression of recombinant human IL-37 protein,Western blotting detect the biology effect of IL-37 protein.8.PBMCs was isolated from OA patients and healthy controls,RT-PCR detect the changes of TNF-α,IL-1β,CXCL8,MMP-3 mRNA expression in PBMCs after recombinant IL-37 protein stimulation,ELISA detect the change of these mediators cell supernatants protein level after recombinant IL-37 protein stimulation.9.Synovial cells was isolated from OA active patients,RT-PCR detect the change of TNF-α,IL-1β,CXCL8,MMP-3 mRNA expression after recombinant IL-37 protein stimulation,ELISA detect the change of these mediators cell supernatants protein level after recombinant IL-37 protein stimulation.Results1.RT-PCR detection showed that compared with the control group,the mRNA expression of IL-37 in PBMCs of OA were significantly higher especially the active OA patients.2.ELISA detection showed that compared with the control group,the serum IL-37 protein level of OA patients were significantly higher especially the active OA patients.3.Clinical data showed that the serum IL-37 protein of OA patients were positively correlated with BMI,CRP and WOMAC.4.RT-PCR detection showed that compared with the control group,the mRNA expression of TNF-α,IL-1β,CXCL8,MMP-3 in PBMCs of OA were significantly higher.5.ELISA detection showed that compared with the control group,the protein level of TNF-α,IL-1β,CXCL8,MMP-3 in serum of OA patients were significantly higher.6.Serum IL-37 protein were positively correlated with TNF-α,IL-1β,CXCL8,MMP-3 in patients with OA.7.RT-PCR detection showed that the mRNA expression of TNF-α,IL-1β,CXCL8,MMP-3 in PBMCs of OA could be inhibited with the stimulation of recombinant IL-37 protein,IL-37 protein had no significant effect on healthy controls.8.ELISA detection showed that the protein levels of TNF-α,IL-1β,CXCL8,MMP-3in serum of OA patients could be inhibited with the stimulation of recombinant IL-37 protein,IL-37 protein had no significant effect on healthy controls.9.RT-PCR detection showed that the mRNA expression of TNF-α,IL-1β,CXCL8,MMP-3 in synovial cells of active OA patients could be inhibited with the stimulation of recombinant IL-37 protein.10.ELISA detection showed that the protein expression of TNF-α,IL-1β,CXCL8,MMP-3 in synovial cell supernatants of active OA patients could be inhibited with the stimulation of recombinant IL-37 protein.Conclusions1.The level of IL-37 was positively correlated with the disease activity of OA.2.The level of IL-37 was positively correlated with the amouts of TNF-α,IL-1β,CXCL8 and MMP3,which played an important role in OA.3.The inflammatory mediators which were related to OA could be inhibited by IL-37.