Expression of Osteogenic Factors in FasL-Deficient Calvarial Cells

During bone development, FasL acts not only through the traditional apoptotic mechanism regulating the amount of boneresorbing osteoclasts, but there is also growing evidence about its effect on cell differentiation. Expression of osteoblastic factors was followed in non-differentiated and differentiating primary calvarial cells obtained from FasL-deficient (gld) mice. The gld cells showed decreased expression of the key osteoblastic molecules osteocalcin (Ocn), osteopontin (Opn), and alkaline phosphatase (Alpl) in both groups. Notably, receptor activator of differentiated gld vs. wild type (wt) cells but decreased in differentiating gld cells. Osteoprotegerin (Opg) in the gld samples pathologies such as osteoporosis.