OBJECTIVEThis study aims to investigate the regulatory effects of calcitonin gene-related peptide (CGRP) on Nod-like receptor protein 3 (NLRP3) and interleukin-1β (IL-1β) to promote osteoblast differentiation.

METHODSDifferent concentrations of CGRP (0, 10, 30, 100 ng · mL⁻¹) were added to mouse osteoblasts in vitro. The mRNA and protein expression levels of both NLRP3 and IL-1β were examined using Real-time polymerase chain reaction and Western blot, respectively. Moreover, the concentrations of IL-1β protein and intracellular reactive oxygen species (ROS) were detected using enzyme-linked immunosorbent assay and flow cytometry, respectively. The osteogenic differentiation of mouse osteoblasts was identified through alizarin red staining.

RESULTSThe protein and mRNA expression levels of both NLRP3 and IL-1β significantly decreased (P < 0.05) with increasing CGRP concentration. Moreover, the contents of intracellular ROS gradually decreased (P<0.05). The osteogenic differentiation of the osteoblasts was more enhanced in the group treated with 100 ng · mL⁻¹ CGRP than in the empty group (0 ng · mL⁻¹ CGRP).

CONCLUSIONCGRP promotes osteoblast differentiation by inhibiting the expression of inflammatory factors.