Figure 6
PGE2 inhibits hBMSC-mediated matrix mineralization via Epac-dependent cAMP signaling. (A) Intracellular cAMP levels were measured in hBMSCs treated with PGE2 (100 nM) for 2, 5 and 15 min. *p < 0.01, **p < 0.001, as compared to untreated cells using ANOVA. (B) hBMSCs undergoing osteogenic differentiation were treated continuously with cAMP analog 8-Br-cAMP, and matrix mineralization quantified at day 14 by Alizarin Red S staining. *p < 0.01, **p < 0.001 as compared to control using ANOVA. (C) hBMSCs were continuously cultured in the absence (control) or presence (PGE2) of PGE2 (10 nM) with or without Epac inhibitor ESI-09 (10 μM) or PKA inhibitor PKI (10 μM), and matrix mineralization quantified at day 14 by Alizarin Red S staining. *p < 0.001 as compared to control using ANOVA. (D) hBMSCs undergoing osteogenic differentiation were treated continuously with cAMP analog 8-pCPT-2-O-Me-cAMP (8-pCPT) (50 μM), and matrix mineralization quantified at day 14 and 16 by Alizarin Red S staining. *p < 0.01, **p < 0.001 as compared to control (−8-pCPT) using Student’s t-test. The data represent triplicate determinations and were replicated at least two times. All values are presented as mean ± S.D.
