Effects of GLP-1 receptor analogue liraglutide and DPP-4 inhibitor vildagliptin on the bone metabolism in ApoE-/- mice

Background: It has been reported that glucagon-like peptide-1 (GLP-1) can alleviate diabetic osteoporosis (DOP). This study was to investigate the effects of GLP-1RA liraglutide and dipeptidyl peptdase-4 (DPP-4) inhibitor vildagliptin on the advanced glycation end products (AGEs)-induced bone injury in ApoE(-/-) mice with euglycemia. Methods: The bone markers OC, PINP, PTH, TRACP and CTX, the mRNA and protein expressions of RAGE in the femur, and the femoral morphology index were determined to evaluate whether the osteoporosis was improved by liraglutide or vildagliptin. Results: AGEs adversely affected the bone metabolism, characterized by reduced OC and increased CTX. However, vildagliptin reduced AGEs and increased OC, and liraglutide significantly decreased AGEs and PTH. Both vildagliptin and liraglutide had no effects on the bone metrology and RAGE expression in the femurs of ApoE(-/-) mice. Conclusions: The elevated AGEs may exacerbate osteogenesis and increase bone resorption, and vildagliptin/liraglutide may improve bone metabolism.