Chemerin mediates exercise-induced improvements of bone microstructure and bone mass in diabetes or high fat diet mice

To clarify the roles and mechanisms of adipokine chemerin in exercise-induced bone improvements in type 2 diabetes mellitus (DM) mice and mice fed on high fat diet (HFD). DM mice were established by HFD + streptozotocin injection, exogenous chemerin was supplemented prior to running, and found that exogenous chemerin reversed 6-week exercise-induced improvements in cancellous bone parameters in DM mice. While adipose-specific chemerin knockout improved microstructure and mass of cancellous bone in HFD mice and further increased exercise-induced bone improvements, accompanied with promoted osteogenesis and inhibited osteoclasis represented as the changes of RANKL, M-CSF, Runx2, Osterix, OPG, ALP and CTSK. These results indicated that reduced chemerin contributed to exercise-induced enhancements in the microstructure and mass of cancellous bone in DM and HFD mice in association with osteogenesis promotion and osteoclasis inhibition, which is beneficial to clarify chemerin's impact on bone remodeling in metabolic diseases at sedentary and exercise states.