[Effect of calcitonin gene-related peptide on RUNX2 expression in primary rat osteoblasts]

To investigate the effects of exogenous calcitonin gene-related peptide (CGRP) on RUNX2 expression in primary cultured rat osteoblasts.

Primary cultured rat osteoblasts were obtained by collagenase / trypsinenzyme digestion from calvarial bone of neonate rats and were identified by ALP staining; The cells were exposed to gradient concentrations, and the effect of CGRP on the proliferation of osteoblasts was determined by MTT assay. The expressions of RUNX2 were quantified by RT-PCR and Western blotting after 48-hour exposure to different CGRP concentrations.

CGRP could promote the proliferation of osteoblasts .When the concentration of CGRP were at 10(-8)-10(-6) mol/L, the proliferation rates of osteoblasts were 71.9%, 142.1%, 321.0%, respectively (P<0.05); when CGRP was at concentrations of 10(-7) and 10(-6) mol /L in osteoblasts for 48 h, the mRNA levels of RUNX2 was significantly increased, which increased (46.2±11.2)% and (58.6±14.0)% respectively (P<0.05); the expression of RUNX2 protein levels was consistent with the change of the mRNA levels.

CGRP could promote RUNX2 expression in primary cultured rat osteoblasts, which suggests that RUNX2 is involved in the mechanism of osteoblast proliferation induced by CGRP.