Loss of Hdac3 in osteoprogenitors increases bone expression of osteoprotegerin, improving systemic insulin sensitivity

Type 2 diabetes is an emerging global health epidemic. Foundations for new therapies are arising from understanding interactions between body systems. Bonederived factors that reduce RANKL (receptor activator of NF-kappa B ligand) signaling in the liver may prevent insulin resistance and the onset of type 2 diabetes. Here we demonstrate that deletion of the epigenetic regulator, Hdac3, in Osx1-expressing osteoprogenitors prevents insulin resistance induced by high fat diet by increasing serum and skeletal gene expression levels of osteoprotegerin (Opg), a natural inhibitor of RANKL signaling. Removal of one Opg allele in mice lacking Hdac3 in Osx1+ osteoprogenitors increases the insulin resistance of the Hdac3-deficient mice on a high fat diet. Thus, Hdac3-depletion in osteoblasts increases expression of Opg, subsequently preserving insulin sensitivity. The Hdac inhibitor vorinostat also increased Opg transcription and histone acetylation of the Opg locus. These results define a new mechanism by which bone regulates systemic insulin sensitivity.