Expression of the calcitonin receptor, calcitonin receptor‐like receptor, and receptor activity modifying proteins during osteoclast differentiation

Abstract

The expressions of the calcitonin receptor (CTR), the calcitonin receptor-like receptor (CLR), the receptor activity-modifying proteins (RAMP) 1-3, and of the receptor component protein (RCP) have been studied in mouse bone marrow macrophages (BMM) during osteoclast differentiation, induced by treatment with M-CSF and RANKL. Analyses of mRNA showed that CLR and RAMP1-3, but not CTR, were expressed in M-CSF stimulated BMM. RANKL gradually increased CTR mRNA, transiently enhanced CLR and transiently decreased RAMP1 mRNA, but did not affect RAMP2, RAMP3, or RCP mRNA. However, RANKL did not affect protein levels of CLR or RAMP1-3 as assessed by Western blots or FACS analyses, whereas immunocytochemistry showed enhanced CTR protein. Analyses of cAMP production showed that BMM cells expressed functional receptors for calcitonin gene-related peptide (CGRP), amylin, adrenomedullin, and intermedin, but not for calcitonin and calcitonin receptor stimulating peptide (CRSP), but that RANKL induced the expression of receptors for calcitonin and CRSP as well. Calcitonin, CGRP, amylin, adrenomedullin, intermedin, and CRSP all down regulated the CTR mRNA, but none of the peptides caused any effects on the expression of CLR or any of the RAMPs. Our data show that BMM cells express receptors for CGRP, amylin, adrenomedullin, and intermedin and that RANKL induces the formation of receptors for calcitonin and CRSP in these cells. We also show, for the first time, that the CTR is not only down regulated by signaling through the CTR but also by the peptides signaling through CLR/RAMPs.

Increase of CGRP-Containing Nerve Fibers in the Rat Periodontal Ligament After Luxation

“…The functional receptor for CGRP is a complex form of RAMP1 and calcitonin receptor-like receptor (Naot and Cornish 2008). Previous studies have demonstrated that these proteins are expressed by osteoblasts in the human as well as bone marrow cells in the human and mouse (Uzan et al 2004;Granholm et al 2008). Osteoclast-like cells from co-cultures of mouse bone marrow cells and spleen cells are devoid of RAMP1 (Granholm et al 2008).…”

“…Previous studies have demonstrated that these proteins are expressed by osteoblasts in the human as well as bone marrow cells in the human and mouse (Uzan et al 2004;Granholm et al 2008). Osteoclast-like cells from co-cultures of mouse bone marrow cells and spleen cells are devoid of RAMP1 (Granholm et al 2008). However, CGRP is known to have effects on rat osteoclasts (Naot and Cornish 2008;Wang et al 2010).…”

Haplotype-based case–control study of receptor (calcitonin) activity-modifying protein-1 gene in cerebral infarction

“…16,17 The human RAMP-1 gene is located on chromosome 2, at 2p36-2q37.1, spanning approximately 60 kb and containing 3 exons. RAMP1 protein has 148 amino acids with a 26-amino-acid N-terminal signal peptide, an extracellular domain of approximately 90 amino acids, a single transmembrane domain of 20 amino acids and a C-terminal tail of 10 amino acids.…”

Peripheral Nerve Fibers and Their Neurotransmitters in Osteoarthritis Pathology

“…The indirect inhibitory effect of CGRP on osteoclastogenesis was demonstrated by regulating the Rankl/OPG ratio in osteoblast-like cells. Besides osteoblasts, osteoclasts and their precursors, bone marrow-derived macrophages (BMM), also express the CGRP receptor complex of CRLR and RAMP1 [106]. In addition, RAMP2 and 3 mRNA and protein expression was detected in osteoclasts, which points to regulatory control from other proteins of the calcitonin family apart from CGRP, i.e., amylin, adrenomedullin and intermedin.…”