Methylprednisolone Inhibits Autophagy of Vascular Endothelial Cells in Rat Femoral Head Via PI3K/Akt/mTOR Pathway

Objective To study the relationship between vascular endothelial cells (VEC) and autophagy, and its regulatory mechanism in steroid‐induced avascular necrosis of the femoral head (SANFH). Methods In cell experiment, VEC were isolated and cultured from the femoral head of Sprague–Dawley rats and divided into three groups: blank control group (Ctrl), methylprednisolone group (MP), and methylprednisolone+mTOR‐shRNA group (MP + shmTOR). The autophagy formation was observed by transmission electron microscope. The mRNA expression of PI3K, Akt, mTOR, Beclin1 and MAP1LC3 was detected by RT‐PCR and the protein expression was detected by Western blot and immunofluorescence. Expression of the damage marker 6‐keto‐PGF1α was detected by the ELISA method. In vivo experiment, after establishing the model, the grouping method was the same as cell experiment. Autophagosomes were observed by same method, and the expression of related factors was detected by the same method in cell experiment. Results In the cell experiment, autophagosomes in the MP group were significantly lower than in the Ctrl group, and the autophagosomes in the MP + shmTOR group were intermediate between two groups (P