Prostaglandin E 2 stimulates collagen and non-collagen protein synthesis and prolyl hydroxylase activity in osteoblastic clone MC3T3-E1 cells

Abstract

We investigated the stimulative effect of prostaglandin E 2 (PGE 2) on an osteoblastic cell line, clone MC3T3-E1, in serum-free medium. PGE 2 elevated collagen and non-collagen protein syntheses in a dose-related fashion up to 2 μg/ml, the maximal increases being 2- and 3-fold, respectively, over that in the control. Its stimulative effect was evident as early as 12 h. PGE 2 slightly increased DNA content, but its effect was less than that on collagen and non-collagen protein syntheses. Moreover, PGE stimulated an increase in prolyl hydroxylase activity with a maximal effect at 1–2 μg/ml, the activity being 15-fold over that of the control. These results strongly indicate that PGE 2 directly enhances total protein synthesis including that of collagen in osteoblasts in vitro , suggesting its direct effect on bone formation in vivo as well.