Sclerostin inhibition of Wnt-3a-induced C3H10T1/2 cell differentiation is indirect and mediated by bone morphogenetic proteins.

High bone mass diseases are caused both by activating mutations in the Wnt pathway and by loss of SOST, a bone morphogenetic protein (BMP) antagonist, leading to the activation of BMP signaling. Given the phenotypic similarity between mutations that activate these signaling pathways, it seems likely that BMPs and Wnts operate in parallel or represent components of the same pathway, modulating osteoblast differentiation. In this study, we show that in C3H10T1/2 cells, Wnt-3A and BMP-6 proteins were inducers of osteoblast differentiation, as measured by alkaline phosphatase (ALP) induction.

Sclerostin promotes the apoptosis of human osteoblastic cells: a novel regulation of bone formation.

A null mutation in the SOST gene is associated with sclerosteosis, an inherited disorder characterized by a high bone mass phenotype. The protein product of the SOST gene, sclerostin, is a bone morphogenetic protein (BMP) antagonist that decreases osteoblast activity and reduces the differentiation of osteoprogenitors. We sought to delineate the mechanism by which sclerostin modulated osteoblastic function by examining the effects of the protein on differentiating cultures of human mesenchymal stem cells (hMSC).

Noggin and sclerostin bone morphogenetic protein antagonists form a mutually inhibitory complex.

Noggin and sclerostin are bone morphogenetic protein (BMP) antagonists that modulate mitogenic activity through sequestering BMPs. Little is known of the interactions among this class of proteins. We show that recombinant sclerostin and noggin bound to each other with high affinity (K(D) = 2.

Osteocyte control of bone formation via sclerostin, a novel BMP antagonist.

There is an unmet medical need for anabolic treatments to restore lost bone. Human genetic bone disorders provide insight into bone regulatory processes. Sclerosteosis is a disease typified by high bone mass due to the loss of SOST expression.