title: CGRP may regulate bone metabolism through stimulating osteoblast differentiation and inhibiting osteoclast formation.
abstract: Calcitonin-gene-related peptide (CGRP) is a neuropeptide, which is widely distributed throughout the central and peripheral nervous systems. Numerous mechanisms underlying the action of CGRP in osteoblast-associated cells have been suggested for bone growth and metabolism. The present study was designed to closely investigate the osteoblast‑ and osteoclast-associated mechanisms of the effect of CGRP administration on bone metabolism in primary osteoblasts. Primary osteoblasts were obtained from newborn rabbit calvaria and incubated with different concentrations of human CGRP (hCGRP), hCGRP and hCGRP (8‑37), or without treatment as a control. Intracellular calcium (Ca2+) and cyclic adenosine monophosphate (cAMP) were detected following treatment, as well as the expression levels of osteoblast differentiation markers, including activating transcription factor‑4 (ATF4) and osteocalcin (OC), and receptor activator of nuclear factor κB ligand (RANKL) and osteoprotegerin (OPG). The isolated primary osteoblasts were found to stain positively for ALP. hCGRP treatment had no significant effect on transient intracellular Ca2+ in the osteoblasts. Treatment of the osteoblasts with hCGRP led to elevations in the expression levels of cAMP, ATF4 and OPG, and downregulation in the expression of RANKL, in a dose‑dependent manner. These effects were markedly reversed by the addition of hCGRP (8‑37). The results of the present study demonstrated that CGRP administration not only stimulated osteoblast differentiation, as demonstrated by upregulated expression levels of ATF4 and OC in the hCGRP‑treated osteoblasts, but also inhibited OPG/RANKL‑regulated osteoclastogenesis. CGRP may act as a modulator of bone metabolism through osteoblast and osteoclast-associated mechanisms, which result in osteoblast formation with subsequent activation of bone formation.
authors.affiliation: Department of Maxillofacial and Head and Neck Surgery, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042, P.R. China.
authors.forename: Haitao
authors.initials: H
authors.lastname: He
authors.affiliation: Department of Maxillofacial and Head and Neck Surgery, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042, P.R. China.
authors.forename: Jianshen
authors.initials: J
authors.lastname: Chai
authors.affiliation: Department of Maxillofacial and Head and Neck Surgery, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042, P.R. China.
authors.forename: Shengfu
authors.initials: S
authors.lastname: Zhang
authors.affiliation: Department of Maxillofacial and Head and Neck Surgery, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042, P.R. China.
authors.forename: Linlin
authors.initials: L
authors.lastname: Ding
authors.affiliation: Department of Maxillofacial and Head and Neck Surgery, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042, P.R. China.
authors.forename: Peng
authors.initials: P
authors.lastname: Yan
authors.affiliation: Department of Maxillofacial and Head and Neck Surgery, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042, P.R. China.
authors.forename: Wenjun
authors.initials: W
authors.lastname: Du
authors.affiliation: Department of Oncology, Cancer Center, Daping Hospital and Research Institute of Surgery, Third Military Medical University, Chongqing 400042, P.R. China.
authors.forename: Zhenzhou
authors.initials: Z
authors.lastname: Yang
mesh_terms: D000818:Animals; D000943:Antigens, Differentiation / Q000378:metabolism; D015740:Calcitonin Gene-Related Peptide / Q000494:pharmacology*; D002454:Cell Differentiation / Q000187:drug effects*; D002478:Cells, Cultured; D010006:Osteoblasts / Q000166:cytology / Q000378:metabolism*; D010010:Osteoclasts / Q000166:cytology / Q000378:metabolism*; D010012:Osteogenesis / Q000187:drug effects*; D010446:Peptide Fragments / Q000494:pharmacology*; D011817:Rabbits; D012886:Skull / Q000166:cytology / Q000378:metabolism
chemical_list: D000943:Antigens, Differentiation; D010446:Peptide Fragments; C058636:calcitonin gene-related peptide (8-37); D015740:Calcitonin Gene-Related Peptide