Expression Prolife Of Cytokines And Chemokines In Patients With Osteoarthritis And The Function Of CXCL8 And CXCL11 In The Regulation Of Chondrocytes

Osteoarthritis(OA) is a common joint disease,which seriously impact human health.OA is mainly manifested as slow development of joint pain,stiffness,and swelling,which is often accompanied by joint dysfunction and may even lead to disabilities.2/3 people with 65 years old or elder suffer with OA.At present,the main method for treatment of OA is to reduce the loading of joints and to avoid over large activities.The usage of anti-inflammatory drugs or cartilage protective agents could also relieve symptoms and improve joint functions when necessary.For patients with late stage OA,the implementation of arthoplasty is currently recognized as the most effective method to eliminate pain,correct deformity,and improve functions,which greatly improve the quality of life of the patients.However,many problems exist in arthoplasty,including costly,tolerance of the patients and need renew of arthoplasty.Moreover,the pathogenesis of OA is not fully elucidated.Thus,there is an urgent need to strengthen the research on the pathogenesis and clinical outcome of OA,and derive and develop more effective therapeutic menthods.The pathogenesis of OA is complicated.Many factors(including genetic factors,immune factors,and lifestyle)affect the incidence of OA.Therefore,it is commonly believed that OA is the systemic failure of one or more joints caused by multiple disorders,rather than an independent disease.Meanwhile,there is interaction between immune response and destruction of articular cartilage as well as synovial tissue,which leads to the chronic inflammation of the joints.Thus,the role of immunological factors in the pathogenesis and clinical outcome of OA has become one of the hot points.A variety of inflammatory cytokines and growth factors are involved in the pathogenesis of OA.The interaction of these molecules results in the corresponding biological effects through different activation pathways,which eventually leads to he degradation of the cartilage matrix and apoptosis of chondrocytes.However,the ability of regeneration and repairment of articular cartilage is very limited.The destruction of cartilage almost can not be reversed.Therefore,it is necessary to effectively intervente the early lesions of OA to delay or even reverse the disease of OA.The key problem is to interpretate the signaling pathway of these cytokines/chemokines and their effects on chondrocytes.However,the current results always focused on a single or several cytokines/chemokines.There are few reports on the expression profile of cytokines and chemokines in OA patients.Moreover,researchers are intend to find the specific genes or factors in regulation of OA,but the impact of these cytokines and chemokines in regulation of chondrocytes was not completely understood.Based on the above questions,we collect the peripheral bloods and synovial fluids of OA patients.The proportions of immune cells and the expressions of cytokines and chemokines were tested by flow cytometry and Milliplex multi-cytokine detection in the peripheral bloods and synovial fluids from both normal controls(NCs)and OA patients.The differential expression of the cells and cytokines between the two groups were analyzed,and the correlation between the expression of these factors and related clinical process were also reported.The primary chondrocytes were isolated from cartilages of OA patients.The primary chondrocytes were stimulated by recombinant CXCL8/IL-8 and CXCL11.The proliferation,apoptosis,life cycle,secretion of cytokines,as well as the signaling pathway of primary chondrocytes in response to stimulation were analyzed.The results were as following:1.There were no significant differences in the proportions of peripheral CD4+ T cells,CD8+ T cells,and B cells between OA patients and NCs.The proportion of NK cells was higher in OA patients than that in NCs.Further findings in the subsets analysis of NK cells showed that the proportion of CD56 brightNK cells,which mainly produce cytokines,was higher in OA patients,while the proportion of CD56 negNK cells with anergy was lower in OA patients.There was no remarkable difference in CD56 dimNK cells with cytotoxic function between OA patients and NCs.2.The expressions of a total of 47 cytokines and chemokines in the peripheral bloods of OA patients were analyzed.Levels of 14 cytokines and chemokines were under the detections of limitation in both OA patients and NCs.There were no notable differences of 26 cytokines and chemokines between OA patients and NCs.Seven of cytokines and chemokines revealed differential expressions between OA patients and NCs.The levels of IL-1β,IL-8,IL-17 A,TNF-α,CXCL9,and CXCL11 were higher in OA patients,while IL-10 expression was lower in OA patients.Effective anti-inflammatory therapy leaded to the reduction of IL-8,IL-17 A,CXCL9,and CXCL11 in the peripheral bloods of RA patients.3.IL-8(CXCL8),IL-17 A,CXCL9,and CXCL11 could be detected in synovial fluids of OA patients.There were no significant differences of IL-17 A and CXCL9 levels in synovial fluids between advanced and late stage OA.However,expressions of CXCL8/IL-8 and CXCL11 were remarkably higher in the synovial fluids of late stage OA than those in advanced OA.4.The primary chondrocytes isolated from the knee cartilage of OA patients were cultured.Recombinant CXCL8 and CXCL11 were used to stimulate the primary chondrocytes.The stimulation of CXCL8 and CXCL11 resulted in the reduction of proliferation.The analysis of cell cycles revealed that the proportion of chondrocytes in S stage was increased,while chondrocytes in G2-M stage was downregulated in response to CXCL8 and CXCL11 stimulation.Meanwhile,the elevation of apoptosis cells was found after stimulation.The secretions of several cytokines,including TNF-α,IL-1β,IL-6,MMP-1,MMP-3,and MMP-13,were also increased in response to CXCL8 and CXCL11 stimulation.CXCL8 and CXCL11 stimulation could also result in the elevation of phosphorylated STAT3 and phosphorylated NF-κB.However,phosphorylated p38 MAPK was not influenced by CXCL8 and CXCL11.In conclusion,high levels of proinflammatory cytokines and chemokines were found in peripheral bloods and synovial fluids of OA patients.Among these cytokines and chemokines,CXCL8 and CXCL11 promote the apoptosis and suppress the proliferation of chondrocytes by influencing JAK-STAT and NF-κB signaling pathway and enhancing the expressions of proinflammatory cytokines.Thus,CXCL8/IL-8 and CXCL11 may promote the disease progression of OA.The current study enhanced the evidence for pathogenesis of OA,and provided the new therapeutic targets of OA.