miR21 deletion in osteocytes has direct and indirect effects on skeletal muscle in a sex-dimorphic manner in mice

Abstract

Highlights Osteocytic microRNA21 (miR21) removal in OtmiR21Δ mice alters cytokine production and bone mass by modulating osteoclast and osteoblast differentiation and activity. Only female, but not male, OtmiR21Δ mice exhibit higher lean body mass and soleus and gastrocnemius muscle weight compared to miR21fl/fl littermates. Sex-dependent consequences of osteocytic miR21 deletion on skeletal muscle were also found at protein and gene expression level. We conclude that osteocyte-derived miR21 influences skeletal muscle size, but not strength, in female but not male mice; whereas, intracellular signaling alterations resulting from loss of miR21 seem to alter protein dynamics in a sex-dimorphic fashion.