First Author | Hoff AO | Year | 2002 |
Journal | J Clin Invest | Volume | 110 |
Issue | 12 | Pages | 1849-57 |
PubMed ID | 12488435 | Mgi Jnum | J:80827 |
Mgi Id | MGI:2447255 | Doi | 10.1172/JCI14218 |
Citation | Hoff AO, et al. (2002) Increased bone mass is an unexpected phenotype associated with deletion of the calcitonin gene. J Clin Invest 110(12):1849-57 |
abstractText | Calcitonin (CT) is a known inhibitor of bone resorption. Calcitonin gene-related peptide-alpha (CGRPalpha), produced by alternative RNA processing of the CT/CGRP gene, has no clearly defined role in bone. To better understand the physiologic role of the CT/CGRP gene we created a mouse in which the coding sequences for both CT and CGRPalpha were deleted by homologous recombination. The CT/CGRP(-/-) knockout (KO) mice procreated normally, there were no identifiable developmental defects at birth, and they had normal baseline calcium-related chemistry values. However, KO animals were more responsive to exogenous human parathyroid hormone as evidenced by a greater increase of the serum calcium concentration and urine deoxypyridinoline crosslinks, an effect reversed by CT and mediated by a greater increase in bone resorption than in controls. Surprisingly, KO mice have significantly greater trabecular bone volume and a 1.5- to 2-fold increase in bone formation at 1 and 3 months of age. This effect appears to be mediated by increased bone formation. In addition, KO mice maintain bone mass following ovariectomy, whereas wild-type mice lose approximately one-third of their bone mass over 2 months. These findings argue for dual roles for CT/CGRP gene products: prevention of bone resorption in hypercalcemic states and a regulatory role in bone formation. |