Influence Of Acupuncture On MMPs And TIMPs Expression In The Cartilage Of Rats With Knee Osteoarthritis

BACKGROUNDOsteoarthritis (OA) is a kind of joint disease with the damage characteristics of articular cartilage degradation, which is one of the most common disease happened on old people. It often leads to the choric pain and loss of joint function. Cartilage degeneration of the basic performance is cartilage extracellular matrix (ECM), mainly is the degradation of the proteoglycan and destruction of collagen fibers network. Many protease involved in the process of this degradation, and the most important one is the matrix metalloproteinases (MMPs). The main function of MMPs is to degenerate basement membrane and extracellular matrix, and it's main physiological inhibitors is tissue inhibitors of metal protease (TIMPs). The dynamic imbalance between MMPs and TIMPs is an important link to the occurrence and development of OA.At present, there is no special treatment of OA. Surgical therapy is suitable for late stage, and conservative treatments are for patients at early and middle stages. Acupuncture is one of the effective nonoperative therapy, which can effectively remit the clinical symptoms, such as relieving the pain, detumescence and improving the function of the knee. But the current researches are mostly on clinic, there are only a little ones on mechanism.OBJECTIVEThrough establishing animal models and using immunohistochemical techniques, to observe the influence effect of acupuncture treatment on matrix metalloproteinases 1(MMP-1), matrix metalloproteinases 3(MMP-3) and tissue inhibitors of metal protease 1(TIMP-1) expression in cartilage of rats with knee osteoarthritis, so as to explore the curative mechanism of acupuncture treatment. It will provide not only theoretical support for clinical practice, but also foundation for future research.METHOD1.40 cases of female SD rats were randomly and averagely divided into four groups:the normal, model, acupuncture and control group. Using the method of heel tendon resection for unilateral hind limb to establish the OA animal models.2. The acupuncture group and control group were respectively treated by electro-acupuncture and Diclofenac for two weeks.3. Used immunohistochemical staining to observe the expression characteristic of MMP-1, MMP-3 and TIMP-1 in cartilage of each group, and compare the differences between the groups.RESULTThere are significant differences between four groups. MMP-1, MMP-3 and TIMP-1 expression in model group, acupuncture group and control group were all significantly stronger than normal group(P<0.01), and there were also significant differences between the later two groups and the model group, showed that MMP-1 and MMP-3 expression was significantly down-regulated (P<0.01), while TIMP-1 expression was significantly up-regulated (P<0.01). The difference between acupuncture group and control group was very significant too (P<0.01). MMP-1 and MMP-3 expressed significantly lower in acupuncture group than in control group (P<0.01), while TIMP-1 expressed significantly higher in acupuncture group(P<0.01). Additionally, although MMP-1, MMP-3 and TIMP-1 expression in model group were all significantly stronger than in normal group, they were up-regulated to different extent. It showed that in model group, TIMP-1 expression was lower than MMP-1 and MMP-3.CONCLUSIONAcupuncture influences the expression of MMP-1, MMP-3 and TIMP-1 in osteoarthritic chondrocytes, which down-regulates the expression of MMP-1 and MMP-3, while up-regulates the expression of TIMP-1,and the regulating effect is stronger than Diclofenac. This shows that acupuncture has a certain protective effect on osteoarthritic cartilage.