Effect of Yang-Warming and Kidney-Tonifying Prescription on Expression of Osteogenic and Angiogenic Factors and H-Type Vascular Markers in Steroid-Induced Avascular Necrosis of Femoral Head in Rabbits

Objective: To investigate the effect of Yang-warming and Kidney-tonifying Prescription (YKP) on the treatment of steroid-induced avascular necrosis of the femoral head (SANFH) in rabbits. And to further explore whether its therapeutic mechanism is related to the expression of HIF-1α and VEGF (angiogenic factors), BMP2 and Osterix (osteogenic factor), CD31 (type H vascular marker) and MMP13 (bone destruction-related factor). Methods: Twenty-seven healthy male New Zealand white rabbits were divided into a normal group, model group, traditional Chinese medcine (TCM) group (clinical equivalent dose group of YKP), miR-130a inhibitor group and TCM + inhibitor group. The SANFH model was established by combining horse serum with methylprednisolone. After the model is successfully established, TCM group was given 6.44 g/kg·d YKP by gavage, and the miR-130a gene inhibitor group was intraperitoneally injected with 25 mg/kg miR-130a inhibitor, locked nucleic acid (LNA)-anti-miR-130a. TCM + inhibitor group was treated with YKP intragastrically and miR-130a inhibitor intraperitoneally. The rabbits in the normal group and the model group were intragastrically administered with normal saline 10 ml/d. Once a day for 4 weeks. The avascular necrosis was detected by HE staining. The contents of HIF-1α, VEGF, BMP2 and Osterix in rabbit tissues were detected by qRT-PCR kit, and the expression of CD31 and MMP13 was detected by immunofluorescence staining. Results: In the normal group, the surface of the cartilage layer of the femoral head was smooth, the bone trabeculae were intact and densely arranged, the cells of each layer were neatly arranged, the morphology of the bone cells, the chondrocytes and the adipocytes were normal. In the model group, cartilage surfaces of the femoral head showed exfoliative cracks. The bone trabecular structure was loose and incomplete, chondrocytes, osteoblasts and bone marrow cells were significantly reduced, and the number of empty bone traps was significantly increased. In the TCM-treated group, more chondrocytes, thicker cartilage layer, and more regular bone trabeculae were detected as compared to model rabbits. In contrast, the cartilage layer was thinner, the destruction and fracture of bone trabeculae was more serious, chondrocytes and osteocytes were decreased as compared to model group. The expression of HIF-1α, VEGF, BMP2, and Osterix in the model group decreased significantly as compared to the normal group (P α), osteogenic-related factors (BMP2 and Osterix), and H-type vascular marker CD31, resulting in increased expressions of VEGF, HIF-α, BMP2, and Osterix, which promote intra-femoral head revascularization. Meanwhile, YKP decreased the expression of bone-destruction-related factor MMP13, thus enhancing the ability of bone tissue to repair itself. Regulation of these molecules’ expression may be one of the mechanisms of YKP in the treatment of hormonal femoral head necrosis.