Expression of NOD2 and NLRP3 in the articular cartilage of a rabbit model of osteoarthritis established by arthrorisis using plaster cast / 中国组织工程研究

ABSTRACT

BACKGROUND: Nucleotide-binding oligomerization domain (NOD)-like receptor plays an important role against inflammatory responses caused by pathogens and non-pathogens, as well as in the initial stage of autoimmune response. Meanwhile, NOD2 and NOD-like receptor protein 3 (NLRP3) are the representative proteins of NOD-like receptor family. OBJECTIVE: To detect the expression of NOD2 and NLRP3 in a rabbit model of osteoarthritis. METHODS: Thirty New Zealand rabbits were randomly divided into six groups (n=5 per group), including five experimental groups (2, 4, 6, 8 and 10 weeks) and one control group. The model of osteoarthritis was established by fixing the left knee joints using plaster cast, and were sacrificed at postoperative 2, 4, 6, 8 and 10 weeks. The controls received no intervention, and were killed at 10 weeks postoperatively. The left distal femur articular cartilage was taken for safranin-fast green staining. The pathological changes were evaluated by Mankin's scores, and the expression levels of NOD2 and NLRP3 were detected by immunohistochemistry. RESULTS AND CONCLUSION: The Mankin's scores in the experimental groups were significantly higher than those in the control group (P <0.01). Moreover, the scores in the experimental groups were significantly increased with time (P < 0.01). The expression levels of NOD2 and NLRP3 in the chondrocytes were also increased with time (P < 0.01). These results indicate that the expresison of NOD2 and NLRP3 in the cartilage cells is positively correlated with the pathological changes of osteoarthritis, which may be through promoting apoptosis in cartilage cells, thus accelerating the development of osteoarthritis.