Department of Orthopedics, The Second Affiliated Hospital of Hunan University of Chinese Medicine, Changsha, China.
Kaohsiung J Med Sci. 2021 Dec;37(12):1089-1100. doi: 10.1002/kjm2.12426. Epub 2021 Aug 2.
Declining autophagy and rising apoptosis are the main factors driving the development of steroid-induced osteonecrosis of the femoral head (SONFH). Here, we showed that astragalus polysaccharide (APS) improved femoral head necrosis via regulation of cell autophagy and apoptosis through microRNA (miR)-206/hypoxia inducible factor-1 (HIF-1α)/BCL2 interacting protein 3 (BNIP3) axis. The expression of miR-206, HIF-1α, and BNIP3 in SONFH specimens and cell model were measured using qPCR. SONFH cell model was treated with APS. Cell autophagy was evaluated using LC3-immunofluorescence assays. Flow cytometry was conducted to assess cell apoptosis. Apoptosis-related proteins and autophagy-related proteins were determined using western blot. Besides, dual-luciferase reporter assay was employed to investigate the relationship between miR-206 and HIF-1α. Here we showed that miR-206 expression was upregulated in SONFH tissues and cell model. APS promoted autophagy and inhibited apoptosis in SONFH cell model via downregulating miR-206. What is more, HIF-1α was the target of miR-206. Knockdown of HIF-1α reversed the recovery effect of miR-206 inhibitor on SONFH cell model. Furthermore, BNIP3 was the target of HIF-1α. HIF-1α overexpression promoted autophagy and inhibited apoptosis, and knockdown of BNIP3 abolished the recovery effect of HIF-1α overexpression in SONFH cell model. These results provided evidence that APS reduced miR-206 expression, and the downregulated miR-206 increased BNIP3 expression by targeting HIF-1α to promote autophagy and inhibit bone cell apoptosis. Our research proved that APS effectively improved SONFH by regulating cell autophagy and apoptosis.
自噬下降和细胞凋亡增加是导致激素性股骨头坏死（SONFH）发展的主要因素。在这里，我们表明黄芪多糖（APS）通过 microRNA（miR）-206/缺氧诱导因子-1（HIF-1α）/BCL2 相互作用蛋白 3（BNIP3）轴调节细胞自噬和凋亡来改善股骨头坏死。使用 qPCR 测量 SONFH 标本和细胞模型中 miR-206、HIF-1α 和 BNIP3 的表达。APS 处理 SONFH 细胞模型。使用 LC3-免疫荧光法评估细胞自噬。通过流式细胞术评估细胞凋亡。使用 Western blot 测定凋亡相关蛋白和自噬相关蛋白。此外，还使用双荧光素酶报告基因实验研究了 miR-206 和 HIF-1α 之间的关系。结果表明，miR-206 在 SONFH 组织和细胞模型中表达上调。APS 通过下调 miR-206 促进 SONFH 细胞模型中的自噬并抑制凋亡。更重要的是，HIF-1α 是 miR-206 的靶基因。敲低 HIF-1α 逆转了 miR-206 抑制剂对 SONFH 细胞模型的恢复作用。此外，BNIP3 是 HIF-1α 的靶基因。HIF-1α 的过表达促进自噬并抑制凋亡，而 BNIP3 的敲低则消除了 HIF-1α 过表达在 SONFH 细胞模型中的恢复作用。这些结果提供了证据表明 APS 通过降低 miR-206 的表达，下调的 miR-206 通过靶向 HIF-1α 增加 BNIP3 的表达来促进自噬并抑制成骨细胞凋亡。我们的研究证明 APS 通过调节细胞自噬和凋亡有效改善 SONFH。
