Granholm Susanne, Lundberg Pernilla, Lerner Ulf H
Department of Oral Cell Biology, Umeå University, Umeå, Sweden.
J Cell Biochem. 2008 Jun 1;104(3):920-33. doi: 10.1002/jcb.21674.
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.
在用M-CSF和RANKL处理诱导破骨细胞分化过程中，对小鼠骨髓巨噬细胞（BMM）中降钙素受体（CTR）、降钙素受体样受体（CLR）、受体活性修饰蛋白（RAMP）1 - 3以及受体成分蛋白（RCP）的表达进行了研究。mRNA分析表明，CLR和RAMP1 - 3在M-CSF刺激的BMM中表达，但CTR不表达。RANKL逐渐增加CTR mRNA，短暂增强CLR并短暂降低RAMP1 mRNA，但不影响RAMP2、RAMP3或RCP mRNA。然而，如通过蛋白质印迹或流式细胞术分析所评估的，RANKL不影响CLR或RAMP1 - 3的蛋白质水平，而免疫细胞化学显示CTR蛋白增加。cAMP产生分析表明，BMM细胞表达降钙素基因相关肽（CGRP）、胰淀素、肾上腺髓质素和中间皮素的功能性受体，但不表达降钙素和降钙素受体刺激肽（CRSP）的受体，但RANKL也诱导降钙素和CRSP受体的表达。降钙素、CGRP、胰淀素、肾上腺髓质素、中间皮素和CRSP均下调CTR mRNA，但这些肽均未对CLR或任何RAMP的表达产生任何影响。我们的数据表明，BMM细胞表达CGRP、胰淀素、肾上腺髓质素和中间皮素的受体，并且RANKL在这些细胞中诱导降钙素和CRSP受体的形成。我们还首次表明，CTR不仅通过CTR信号传导下调，还通过CLR/RAMPs信号传导的肽下调。
