The Expression Of Aggrecanase And MMP In Serum Of OA And The Study Of Relation Between Different Stages Of MRI And The Expression In Serum

Background and ObjectivesOsteoarthritis (OA) is a degenerative joint disorder characterized by destruction and loss of articular cartilage as a result of an imbalance between catabolic and anabolic cartilage matrix metabolism. It is the most common form of arthritis.Degradation of extracellular matrix (ECM) is main feature for destruction of articular cartilage, in which aggrecan is seriously cleaved by matrix metalloproteinase (MMP) and aggrecanase at Asn341-Phe342 and Glu373-Ala374 site of the aggrecan core protein within the interglobular domain (IGD), respectively. Though both aggrecanase and MMP can cleave aggrecan at core protein region, it is controversial that which group of the enzymes plays the major role under pathological condition.Both aggrecanase-1 and aggrecanase-2 were designated as ADAMTS-4 and ADAMTS-5 in that order, are the two widely admitted aggrecanase of the ADAMTS (a disintegrin and metalloproteinase with thrombospondin motifs) gene family. For MMP family, MMP-3 is mainly responsible for degradation of aggrecan among the MMP family.The in vitro cartilage explant system has confirmed that aggrecanase appears to be the primary enzyme to degrade aggrecan in the first several weeks and then MMP in the later weeks. However, the proteolytic activity of aggrecanase at the late stage of cartilage degradation remains unknown. The mediators which regulate the expression of aggrecanases and MMP in serum are more complicated,and the related reports and the studies are not consistent.To detect the expression of ADAMTS-4, ADAMTS-5, MMP-1, and MMP-3 in the serum of early and late OA patients,and to explore the different effecs of ADAMTS and MMP on OA patients. To analyze the relation between different stages of MRI and expression of ADAMTS and MMP. Methods70 subjects went to see a doctor at Bone and Joint Center in Qianfoshan Hospital Affiliated to Shandong Uiversity from June,2008 to October 2009.29 men,41 women;mean age,39.7years; 19～57 years.Both sides of knee joint conform to knee joint OA diagnosis which the China Medical Association Orthopedics Branch promulgated in 2007.70 subjects were grouped based on the MRI Recht graded standard into early OA (44 cases) and late OA groups (26 cases).The normal group occpuied 30 cases. The levels of ADAMTS-4, ADAMTS-5, MMP-1, MMP-3 in the three groups were investigated by enzyme-linked immunosorbent assay(ELISA).The optical densities (OD) represented the level of the expression.The results were analyzed by statistical analysis. In addition,to compare the expression of ADAMTS and MMP with the different stages of MRI. The relation between the expression of ADAMTS and MMP and the different stages of MRI was also observed.ResultsADAMTS-4 had higher expression in early OA group than that in late OA group (P<0.05). ADAMTS-5, MMP-1, MMP-3 had lower expression in early OA group than that in late OA group (P<0.05). Only few ADAMTS-4,-5 and MMP-1 were expressed in the contrast group.ConclusionADAMTS-4 has high expression in early OA group,and indicates that ADAMTS-4 has values in the early diagnosis of OA. ADAMTS-5, MMP-1, and MMP-3 have high expression in late OA group, and indicates that ADAMTS-5, MMP-1, and MMP-3 have not values in the early diagnosis of OA.The expression of ADAMTS-4 is not consistent with the different stages of MRI, however,the expression of ADAMTS-5, MMP-1, and MMP-3 is consistent with the different stages of MRI.