Figure 3. Furin but not PC5 is necessary for pro-OCN processing in osteoblasts.

(A) Cre-mediated inactivation of Furin in Furin^fl/fl osteoblasts infected with either Ad-GFP (i.e., control osteoblasts) or Ad-Cre (i.e., Furin^–/– osteoblasts) was assessed by qPCR (n = 3). (B) Western blot analysis of secreted OCN from differentiated Furin^fl/fl osteoblasts infected with either Ad-GFP or Ad-Cre. (C) Cre-mediated inactivation of Pcsk5 in Pcsk5^fl/fl osteoblasts infected with either Ad-GFP or Ad-Cre was assessed by qPCR (n = 3). (D) Western blot analysis of secreted OCN from differentiated Pcsk5^fl/fl osteoblasts infected with either Ad-GFP or Ad-Cre. (E) Western blot analysis of secreted OCN from differentiated Furin^fl/fl mouse calvaria osteoblasts infected with either Ad-GFP or Ad-Cre and treated or not with 50 μM Dec-RVKR-CMK or 20 μM D6R. Results represent the mean ± SEM. **P < 0.01 and ***P < 0.001, by unpaired, 2-tailed Student’s t test.