Effect of strontium ranelate on rabbits with steroid-induced osteonecrosis of femoral head through TGF-β1/BMP2 pathway.

OBJECTIVE: To study the effect of strontium ranelate (SR) on steroid-induced osteonecrosis of the femoral head (SIONFH) in rabbits and its regulatory mechanism. MATERIALS AND METHODS: The ONFH model was established in 30 rabbits using steroid and they were randomly divided into Control group. Model group, and SR group. After SR intervention, the rabbits were sacrificed and sampled. The pathological injury of the femoral head in each group was detected via hematoxylin-eosin (HE) staining. the level of vascular endothelial growth factor (VEGF) in the femoral head in each group was detected via enzyme-linked immunosorbent assay (ELISA). The messenger ribonucleic acid (mRNA) and protein expression levels of transforming growth factor-beta 1 (TGF-beta 1), as well as the bone morphogenetic protein 2 (BMP2) in the femoral head in each group, were determined using Reverse Transcription-Polymerase Chain Reaction (RT-PCR) and Western blotting. RESULTS: The rabbit model of SIONFH was successfully established. Compared with Control group, the Model group had a severer pathological injury of the femoral head. a lower level of VEGF in the femoral head, significantly decreased mRNA and protein levels of TGF-beta 1 and BMP2. Compared with Model group, the SR group had markedly improved pathological injury of the femoral head, a higher level of VEGF in the femoral head, significantly increased mRNA and protein levels of TGF-beta 1, as well as BMP2. CONCLUSIONS: SR can remarkably improve the pathological injury of the femoral head and increase the expression of VEGF in SIONFH rabbits. whose potential mechanism may be related to the activation of the TGF-beta 1/BMP2 signaling pathway.