Insulin-like growth factor-1(IGF-1) prevents apoptosis in endplate chondrocytes by anti-Fas antibody-induced

摘要

Objectives. To determine whether Fas antibody-Fas interaction induced apoptotic changes in cultured endplate chondrocytes, and whether treatment with insulin-like growth factor-1 (IGF-1) blocked these effects. The expression of the extracellular matrix proteins integrin-β1 and focal adhesion kinase (FAK) in conjunction with apoptosis was also investigated. Materials and Methods. Rat cervical endplate chondrocytes were cultured and treated with Fas antibody, with or without human recombinant IGF-1. Cellular morphology was examined by light microscopy. Apoptotic changes were evaluated by transmission electron microscopy, TUNEL staining, and immunostaining of Bax and bcl-2. Apoptosis induced changes in the expression of integrin-β1 chain and FAK were investigated using real-time PCR, immunostaining, and Western blot. Results. Vertebral endplate chondrocytes were able to be cultured, with maintenance of a chondrocytic phenotype. Fas antibody induced apoptotic changes in endiplate chondrocytes. TUNEL staining confirmed increased apoptosis in antibody treated cells. Expression of bcl-2 was decreased by Fas antibody, while expression of Bax was increased. Expression of integrin-β1 and FAK were increased by Fas antibody treatment. Co-treatment with IGF-1 rescued cells from these Fas antibody-induced changes. Conclusions. Fas antibody induces apoptosis of cultured vertebral endplate chondrocytes. IGF-1 protects these chondrocytes from Fas antibody-induced apoptosis, and inhibited expression of integrin-β1 and FAK. Further studies are needed to define the role of integrin-β1 and FAK in apoptosis.