Pravastatin prevents steroid-induced osteonecrosis in rats by suppressing PPARγ expression and activating Wnt signaling pathway

Steroid-induced osteonecrosis of the femoral head (steroid-induced ONFH) is characterized by increase of intraosseous pressure because of lipid metabolism disturbance such as elevation of adipogenesis and fat cell hypertrophy in the bone marrow, subsequently leading to disturbances of coagulation-fibrinolysis system in the femoral head and finally resulting in bone ischemia. Pravastatin has been demonstrated to be useful in preventing steroid-induced ONFH in animal models. However, its exact mechanisms acting on this disease have not been fully elucidated. To address this problem, steroid-induced ONFH rat model was constructed to evaluate the effects of pravastatin treatment on the osteonecrotic changes and repair processes. Then, Micro-CT-based micro-angiography was performed to assess the effects of pravastatin treatment on vascularization. In addition, serum lipid levels were detected by haematological examination. After that, the expression of peroxisome proliferator-activated receptor gamma (PPARγ), ...