Targeted disruption of cadherin-11 leads to a reduction in bone density incalvaria and long bone metaphyses

The migration and adhesion of osteoblasts requires several classical cadher ins, Cadherin-11, one of the classical cadherins, was expressed in mouse os teoblasts in skull bone and femur, revealed by immunohistochemistry. To elu cidate the function of cadherin-ll in osteoblastogenesis, cadherin-ll null mutant mice were investigated, Although apparently normal at birth, Alizari n red staining of null mutant mice showed a reduced calcified area at the f rontal suture that caused a round-shaped calvaria with increasing animal ag e to 3 months. Consequently, there was a reduction in bone density at the f emoral metaphyses and the diploe of calvaria in null mutant mice. In the in vitro culture of newborn calvarial cells, the calcified area-of mutant cel ls was smaller than those derived from wild-type littermates. These results show that absence of cadherin-ll leads to reduced bone density in some par ts of skeletons including calvaria and long bone metaphyses, and thus sugge st that cadherin-ll plays roles in the regulation of osteoblast differentia tion and in the mineralization of the osteoid matrix.