Résumé
BACKGROUND: Recent studies have demonstrated that sterol regulatory element binding protein-2 (SREBP-2) plays a key role in osteoarthritis, but its exact pathogenesis remains incompletely understood yet. OBJECTIVE:To investigate the expression of SREBP-2 in the process of interleukin-1β-induced articular chondrocyte degenerationin vitro. METHODS: Articular chondrocytes obtained from C57BL/6J mice were culturedin vitro. After the second passage, cels were randomly divided into four groups: control group, and three experimental groups treated with 10 μg/L interleukin-1β for 24, 48 and 72 hours, respectively. RESULTS AND CONCLUSION:The cels became hypertrophic after being stimulated by interleukin-1β, and the staining of colagen X was positive at 72 hours. MTT assay demonstrated that the cel activity after stimulation with interleukin-1β decreased with time. Results of RT-PCR showed that the expression of SREBP-2 and SREBP cleavage activating protein mRNA was significantly increased after stimulation with interleukin-1βas compared with the control group and increased with time. On the contrary, the expression of aggrecan and colagen II mRNA was decreased with time. It is revealed that interleukin-1β could inhibit the proliferation of regular chondrocytes and the expression of its extracelular matrix, and furthermore, induce chondrocyte hypertrophy. The expression of SREBP-2 showed a negative relationship with key cartilage genes during this interleukin-1β-induced degeneration.