... in the mouse skeleton, where bone mass is reciprocally regulated by BMP signaling and activin and TGFβ signaling. We found that deleting Bmpr2 in mouse skeletal progenitor cells ( Bmpr2 -cKO mice) selectively impaired activin signaling but had no effect on BMP signaling, resulting in an increased bone...

... in osteoblasts led to decreased trabecular bone mass with a reduced bone formation rate and a decreased bone resorption. Bones from Gab1 mutants also exhibited inferior mechanical properties. Moreover, primary osteoblasts from Gab1 mutant mice demonstrated markedly suppressed osteoblast mineralization, increased...

... in maintaining bone homeostasis, we disrupted the Smad4 gene in differentiated osteoblasts using the Cre-loxP system. The Smad4 mutant mice exhibited lower bone mass up to 6 months of age. The proliferation and function of the mutant osteoblasts were significantly decreased. Bone mineral density, bone volume...