Zuo Rongtai, Cao Bojun, Kong Lingchi, Wang Feng, Li Shanyu, Shan Haojie, Guan Junjie, Kang Qinglin
Department of Orthopedics, Shanghai Sixth People's Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, 200233, China.
J Orthop Translat. 2025 Feb 12;51:337-358. doi: 10.1016/j.jot.2024.10.014. eCollection 2025 Mar.
Osteonecrosis of the femoral head (ONFH) represents a severe complication of glucocorticoids (GCs) therapy in clinical settings. MicroRNAs (miRNAs) are critically involved in the progression of GCs-induced ONFH, with ferroptosis playing a central role in its pathology. However, the regulatory effects of specific miRNAs targeting ferroptosis in ONFH have not been previously explored. The aim of this study was to elucidate the effect and the specific molecular mechanisms of miR-370-3p in the progression of GCs-induced ONFH.
In this study, we first established a rat model of GCs-induced ONFH and analyzed changes in osteogenesis and ferroptosis. Subsequently, we performed miRNA sequencing on bone marrow-derived mesenchymal stem cells (BMSCs) after dexamethasone treatment. In vitro, we assessed the effects of miR-370-3p on cell proliferation, osteogenic activities, and ferroptosis in BMSCs. We used dual luciferase assays to identify the target gene of miR-370-3p, examining its regulatory effects on osteogenesis and ferroptosis. In vivo, we estimated the effect of miR-370-3p on the femoral head by isolating exosomes from BMSCs overexpressing miR-370-3p and administering them to rats.
We observed that impaired osteogenesis and enhanced ferroptosis are principal pathogenic factors in the progression of GCs-induced ONFH. We identified miR-370-3p as a significant regulatory element in bone marrow-derived mesenchymal stem cells (BMSCs) through miRNA sequencing following GCs treatment. Moreover, miR-370-3p could protect BMSCs viability against GCs impairment in vitro and enhance Ki67 expression in the femoral head. The osteogenic capacity of BMSCs was strengthened by miR-370-3p under GCs condition. In addition, miR-370-3p was found to reduce ferroptosis activities, including iron overload and lipid peroxidation. Mechanically, we found that toll-like receptor 4 (TLR4) was the target of miR-370-3p. And miR-370-3p could exert critical regulatory effects by targeting TLR4/solute carrier family 7 member 11 (SLC7A11)/glutathione peroxidase 4 (GPX4) axis under GCs intervention. Importantly, inhibition of ferroptosis partially restored osteogenic capacity of BMSCs in vitro. In a rat model of GCs-induced ONFH, miR-370-3p played a critical protective role in the femoral head by enhancing osteogenesis and inhibiting ferroptosis.
miR-370-3p could regulate the changes in osteogenesis and ferroptosis in the progression of GCs-induced ONFH through targeting TLR4/SLC7A11/GPX4 axis.
This study is the first to unveil the regulatory interaction between miRNA and ferroptosis in GC-induced ONFH, providing valuable insights into its pathogenesis and identifying potential therapeutic targets.
股骨头坏死（ONFH）是临床糖皮质激素（GCs）治疗的严重并发症。微小RNA（miRNAs）在GCs诱导的ONFH进展中起关键作用，铁死亡在其病理过程中起核心作用。然而，此前尚未探索特定miRNAs靶向铁死亡对ONFH的调控作用。本研究旨在阐明miR-370-3p在GCs诱导的ONFH进展中的作用及具体分子机制。
在本研究中，我们首先建立了GCs诱导的ONFH大鼠模型，并分析了成骨和铁死亡的变化。随后，我们对经地塞米松处理后的骨髓间充质干细胞（BMSCs）进行了miRNA测序。在体外，我们评估了miR-370-3p对BMSCs细胞增殖、成骨活性和铁死亡的影响。我们使用双荧光素酶测定法鉴定miR-370-3p的靶基因，研究其对成骨和铁死亡的调控作用。在体内，我们通过从过表达miR-370-3p的BMSCs中分离外泌体并将其给予大鼠，评估miR-370-3p对股骨头的影响。
我们观察到成骨受损和铁死亡增强是GCs诱导的ONFH进展中的主要致病因素。通过GCs处理后的miRNA测序，我们确定miR-370-3p是骨髓间充质干细胞（BMSCs）中的一个重要调控元件。此外，miR-370-3p可在体外保护BMSCs活力免受GCs损伤，并增强股骨头中Ki67的表达。在GCs条件下，miR-370-3p增强了BMSCs的成骨能力。此外，发现miR-370-3p可降低铁死亡活性，包括铁过载和脂质过氧化。机制上，我们发现Toll样受体4（TLR4）是miR-370-3p的靶标。并且在GCs干预下，miR-370-3p可通过靶向TLR4/溶质载体家族7成员11（SLC7A11）/谷胱甘肽过氧化物酶4（GPX4）轴发挥关键调控作用。重要的是，抑制铁死亡部分恢复了体外BMSCs的成骨能力。在GCs诱导的ONFH大鼠模型中，miR-370-3p通过增强成骨和抑制铁死亡在股骨头中发挥关键保护作用。
miR-370-3p可通过靶向TLR4/SLC7A11/GPX4轴调节GCs诱导的ONFH进展中的成骨和铁死亡变化。
本研究首次揭示了miRNA与铁死亡在GC诱导的ONFH中的调控相互作用，为其发病机制提供了有价值的见解，并确定了潜在的治疗靶点。
