Expression And Significance Of Matrix Metalloproteinase-9 In The Serum Of Knee Osteoarthritic Patients

Osteoarthritis (OA) is common in the elderly prone to articular cartilage and subchondral bone lesions and bone sclerosis, osteophyte formation characterized by a chronic degenerative joint disease.Clinically, with joint pain swelling, dysfunction, mainly caused by the elderly is one of the main pain and disability.Matrix metalloproteinases(MMPs) is a degradation of almost all of the extracellular matrix (ECM) features a family of enzymes ,present in the normal human body, involved in wound healing, cartilage matrix degradation, bone resorption, and decomposition of extracellular matrix diseases, such as the rheumatoid arthritis (RA), osteoarthritis (OA), periodontal disease and cancer and so on. Gelatinase B (MMP - 9) the major degradation of gelatin andⅣ,Ⅴ,Ⅶ,Ⅹ-type basement membrane collagen, in the adhesion between cells and matrix plays an important role. MMP-9 is the MMPs in the degradation of basement membrane is one of the most important protease, from a variety of cells in zymogen form in the intracellular synthesis and eventually be secreted into the extracellular, and under the control of a variety of factors play a role in the ECM enzyme solution effect, leading to articular cartilage ECM in the typeⅡcollagen, proteoglycans and elastic fibers such as excessive degradation, so that articular cartilage damage, degeneration, leading to the occurrence of osteoarthritis of the knee. .Objective: This study aims to explore the OA serum MMP-9 expression and significance, in order to further study the pathogenesis of osteoarthritis provide a basis. Serological tests are noninvasive and have a simple and practical advantages in clinical widely carried out.Methods: Second Hospital of Jilin University from June 2008 to November 2009 during the out-patient and hospitalization in patients with osteoarthritis of the knee for the experimental group, 30 cases, and the other to take the Second Hospital of Jilin University, the health examination of 30 cases of human serum the normal control group. ELISA assay using 30 cases of OA patients and 30 normal control group, serum MMP-9, immediately after the termination of reaction with the microplate reader at a wavelength of 450nm at scan, according to standard concentration and the OD should be out of the hole concentration. Statistical analysis using SPSS13.0 software, ELISA results (ng / ml) with mean±standard deviation (±s), said measurement data using t test and SNK-q test, P <0.05 as statistically significant.Results: Expression of MMP-9 in serum in 30 cases of OA patients and 30 cases of healthy human were: 14.91±4.909ng/ml, 9.598±2.396ng/ml. Expression of MMP-9 in serum of KOA in early, mid and late were 17.613±5.186ng/ml, 14.632±4.599ng/ml, 11.915±3.116ng/ml.In control group, expression of MMP-9 in serum in 15 males were 9.965±2.42ng/ml; Expression of MMP-9 in serum in 15 females were 9.23±2.398ng/ml. In experimental group, expression of MMP-9 in serum in 14 males were 13.528±4.469ng/ml; Expression of MMP-9 in serum in 16 females were 16.119±5.093ng/ml. In experimental group, expression of MMP-9 in serum in 10 cases of less 50 years (including 50 years old) were 15.261±4.228ng/ml; Expression of MMP-9 in serum in 20 cases of over 50 years (including 50 years old) were 14.734±5.311ng/ml.In control group, expression of MMP-9 in serum in 17 cases of less 50 years (including 50 years old) were 9.55±2.165ng/ml ng/ml; Expression of MMP-9 in serum in 20 cases of over 50 years (including 50 years old) were 9.66±2.76ng/ml.There are obvious differences compared experimental group with control group(P <0.01). There are no significant differences compared control group with late stage of KOA (P>0.05). There are statistics significances compared between the early stage and the late stage about the levels of MMP-9 in serum(P <0.01). There are no significant differences compared men and women in experimental group (P>0.05).There are no significant differences compared cases of less 50 years and cases of over 50 years in experimental group(P>0.05).Discussion: osteoarthritis (Osteoathritis, OA) that affect human health, one of the most common joint diseases, with the aging population increases, OA incidence rates on the rise. Osteoarthritis is a form of articular cartilage damage characterized by degenerative disease, is the most common non-inflammatory synovial joint disease, expressed as articular cartilage damage, synovial cell hyperplasia, synovitis, joint subchondral bone sclerosis , surface and marginal osteophyte formation, joint space narrowing. In the pathogenesis of osteoarthritis, the articular cartilage wear and tear or cartilage cells were occurring metabolic abnormalities, injury of articular cartilage cells and synovial cells to secrete an excessive amount of MMPs, breaking the MMP-TIMP balance, resulting in degradation of cartilage matrix, there collagen protein network fault, network proteoglycan degradation in the mechanical load and the role of inflammatory factors, the articular cartilage decline in the ability of anti-stress, allowing the destruction of articular cartilage. Large number of studies confirm that at home and abroad, MMPs in osteoarthritis cartilage matrix degradation play an important role in the process, and through MMPs between, MMPs and various cytokines in the interaction between damaged articular cartilage. In this study, concentrations of MMP-9 were detected by the method of ELASA in serum of 30 cases of OA patients and 30 healthy people , the results showed that: concentrations of MMP-9 in serum of early stage were significantly higher than the late group.That is mean articular cartilage extracellular matrix degenerate activitily in early a stage of KOA. KOA early onset disease mainly the destruction of articular cartilage, while MMP-9 is the degradation of the main members of the extracellular matrix, once again confirmed the MMP-9 play a role in the development of KOA ,and probably play a main role in the development of early stage of KOA. At the same time omparison between different gender and age in two groups ,the results show that gender and age was less affected the expression of MMP-9 in serum. MMP-9 through the degradation of gelatin and collagen fibers, breaking the normal articular cartilage synthesis and metabolic balance, so that network arch articular cartilage matrix structure and integrity of mechanical damage, leading to articular cartilage structure and function of the withdrawal change. The pathogenesis of OA is an extremely complex process, at home and abroad in recent years, the pathogenesis of osteoarthritis from a different point of view a lot of research, but not yet fully clear, by measuring the serum of patients with OA of the MMP-9 is more accurate understanding of OA of the lesions, how to reduce the harmful factors of intra-articular protection of articular cartilage; but also through a number of indicators to predict the development of OA, more importantly, by detecting some of the indicators available to a non-invasive, and specific , sensitive new means of diagnosis of OA.Conclusion: concentrations of MMP-9 in serum of expression group were significantly higher than the control group and oncentrations of MMP-9 in serum of early stage were significantly higher than the late stage in expression group.The levels of MMP-9 in serum were significantly higher than the late group. There are obvious significance compared the same sex in two groups,while there are no significance compared between different sex in experimental group.Gender factor has little effect with the concentrations of MMP-9 in serum. Age factor also has little effect with the concentrations of MMP-9 in serum. The concentrations of MMP-9 in serum in KOA were significantly higher than the same age in normal people. The results show that MMP-9 involved in the development of KOA and mainly in the incidence of early stage.Articular cartilage extracellular matrix degenerate activitily in early stage of KOA and decreasing in the late stage of KOA.