Expression Of TLRs And The Effects Of The Intervention Of Calcitonin In Rat Osteoarthritis Cartilage

Objective: To study the characteristics of the expression of Toll-like receptors ( TLRs) in chondrocyte in the process of Osteoarthritis(OA), and the effect after the intervention of Calcitonin (CT) .Methods: 75 SD rats were randomly divided into three groups, of which Surgery group and CT intervened group both consisted 35 rats, while non-surgery group consisted 5. Surgery Group and CT intervened Group were intervened by cutting off the anterior cruciate ligament and the medial meniscus of their right knees, while the left knees as the control samples. For the non-surgery group, we did not deal with the cruciate ligaments and meniscus , but only exposed the knee joint cavity. CT intervened Group were subcutaneous injected with CT 15IU/kg every other day from the second day of the surgery. The rats of CT intervened Group and Surgery Group were executed and the samples were extracted at 7,10,14,21,28,42, and 56 days after the surgery with 5 rats each time. Non-surgery group rats were executed at 56 days after knee joint exposion. Specimen's general and histological sections were observed. Both sides of the knee cartilage specimens were carried out within the TLR2,TLR3,TLR4 expression detection by Real-time PCR.Results: The model of Group ACLT+MMx can be seen the histological changes 7 days after surgery; after 10 days the general observation of cartilage surface appears dull; after 28 days the formation of osteophyte were shown; after 56 days the defection of cartilage can be seen with exposion of subchondral bone. It is witnessed the development of Mankin score from 7 days of 1.0 to 28 days to 56 days of 6.6 points to 12.2 points. It were significantly different compared with the non-operated group. The expression of TLR2 of the knee cartilage cells of Group ACLT+MMx increased early and inhibited remarkablely in the later stage. The expression of TLR3 was correlated with the severity of diseases. The expression of TLR4 was high but does not change with the course of OA. After using the intervention of Calcitonin, the early expression of TLR2 was inhibited while 28d later the inhibition stopped and the expression increased. TLR3 expression was curtailed early with no change of the increasing tendency. The expression of TLR4 in early stage was also being inhibited.Conclusion: The resection of anterior cruciate ligament and medial meniscectomy can effectively produce rat OA model. The expression of TLRs in OA process of chondrocyte, of which TLR2 first increased, then decreased, the trend of expression of TLR3 was correlated with the disease severity. The expression of TLR4 was high but does not change with the course of OA. The expression of TLRs was significantly reduced and the symptoms of OA can significantly improve after using the intervention of Calcitonin, especially in the early stage , which have a certain therapeutic effect on OA.