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

ABSTRACT

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