The roles of IL-1β on the cartilage endplate chondrocytes of New Zealand white rabbits

Objective: To evaluate the biological roles of IL-1β on the cartilage endplate cells (chondrocytes). Methods: The chondrocytes were isolated and harvested from the cartilage endplate of New Zealand rabbits and then their biological characteristics were identified by different methods. After adding IL-1βwith different concentrations into culture medium respectively, the rate of the proliferation of chondrocyte in different time were measured with MTT. The change of Bax, Bcl-2, Fas and Caspase-3 were measured by immunocytochemistry, and the change of the mRNA of aggrecan and type Ⅱ collagen were measured by RT-PCR. Results: 50 ng/ml and 100 ng/ml IL-1β decreased the rate of the proliferation of chondrocytes. 10 ng/ml and 50 ng/ml IL-1β increased the level of Bax, Fas and caspase-3, only 50 ng/ml IL-1βdecreased the level of Bcl-2. 10 ng/ml and 50 ng/ml IL-1β decreased the aggrecan and collagen IIa mRNA. Conclusions: IL-1β can not only inhibit the proliferation and the matrix synthesis of chondrocyte, but also increase the rate of the apoptosis of chondrocyte.