The Expression Of Oncostatin M In Knee Osteoarthritis

ObjectiveOsteoarthritis is a kind of common multiple-factor-related disease, with its incidence increases over the years. Its predominant pathological change is the articular cartilage degeneration and osteophyte formation. The complex etiology and pathogenesis have not been fully explained. Recent researches have confirmed that the systemic or local changes of cell factors lead to destruction of articular cartilage matrix and bone hyperplasia. As is known, IL-1and IL-6are crucial regulators of inflammation, which also involve in the process of OA. Oncostatin M is a member of IL-6family, and it could regulate the activity of osteoblast. Researches focused on the functions and mechanisms of OSM in OA have not been stained yet. In this study we aim to detect the expression of oncostatin M in the synovium of OA patient, and to explore the relationship between oncostatin M and OA.Materials and Methods1. We collected51specimens from OA and meniscus injury patients. Based on osteoarthritis diagnosis standard reference X-ray Altman and Ahiback X-ray classification method, the specimens are divided into three groups. Group A(Serious OA Group):33patients(33knees), male8cases (8knees), female25cases (25knees), aged47-75years, mean age58.9years, and knee lesions X-ray class3above; Group B(Slight OA Group)10patients in OA mild group (10knee), male in1(1knee), female9cases (9knees), aged42-58years old, mean age49.3years, the course of less than3years, and knee lesions X-ray classification level1,2. Group C(Suffered from lateral discoid without OA)8cases with disk meniscus for patients were conducted as normal control group,8cases (8knee), male4cases (4knee), female4cases (4knee),16-24years old, mean age18.9years.2. Each specimen was divided into two copies,one of which was preserved in-80℃refrigerator, and the other was fixed with4%paraformaldehyde. The synovial tissue samples stored in-80℃refrigerator were sheared to size5×5×5mm. Then total RNA were extracted from tissue with Trizol,and acquired cDNA through reveres transcription PCR. Using GAPDH as an internal, we performed quantitative real-time PCR to gain the amplification of purpose gene and GAPDH genes. After48hours with4%paraformaldehyde,synovial specimens went through dehydration, transparent and dewaxing, then they were cut into5μm thick sections. Two step methods of immunohistochemical was used to detect the expression of OSM in synovial organization.ResultsWith the application of relative quantitative analysis method on the OSM expression, the gene expression level in group B is higher than those in the group C, and there is no significant difference statistically(P>0.05); group A is higher than group B and C, the difference was statistically significant (P<0.05).In immunohistochemical test, OSM is positively expressed in group B knee synovial cells, in endothelial cells and in mononuclear cells and/or the lymphatic cells in both group A and B, in which membrane or cytoplasm stain dark, brown and grain as positive. And it is slightly expressed in normal knee synovial cells. The expression of OSM in the synovium of group A and B are higher than group C, and group A increased significantly,the difference was statistically significant (p<0.05). With the study of the relationship between OSM expression and clinical features, we find that there is positive corelation between the expression of OSM.ConclusionThe OSM in synovium exists widely,and it increases gradually with OA aggravation. In the pathogenesis of OA, OSM has played an important role.