Abstract: Objective Previous studies have clarified that calcitonin gene-related peptide (CGRP) can promote the biological activity of osteoblasts. To further reveal the role of CGRP in bone repair, we studied its influence on osteogenic differentiation of mouse bone marrow stromal cells (BMSCs) and initially explored the effect of the Hippo signaling pathway with this process. Methods BMSCs were induced to osteogenic differentiate osteoblasts by different concentrations of CGRP for a screening of the optimal concentration. CGRP was added in BMSCs, then the activity of alkaline phosphatase (ALP) and the number of mineralized nodules were examined by specific ALP kits after 48 hours and alizarin red staining fluid after 7 days, respectively. The protein expression of p-Mst1/2 was measured byWestern blot. Verteporfin was used to block the downstream Yap signaling. The mRNA expression of collagen typeⅠ(ColⅠ) and runt-related transcription factor 2 (Runx2) were detected by reverse transcription-polymerase chain reaction. Results Compared to the blank group, different concentrations of CGRP (10^-9, 10^-8, 10^-7 mol·L^-1), especially 10^-8 mol·L^-1, significantly increased the ALP activity of BMSCs (P<0.05). Alizarin red staining also showed more mineralized nodules in 10^-8 mol·L^-1 group. The expression of p-Mst1/2 increased in the CGRP group (P<0.05). Verteporfin treatment effectively decreased the mRNA expression of Runx2 and ColⅠ(P<0.05). Conclusion The Hippo signaling pathway plays a role in CGRP-induced osteogenic differentiation in mouse BMSCs.

Key words: calcitonin gene-related peptide, bone marrow stromal cells, Hippo signaling pathway