Exosomes were found to exert a therapeutic effect in the treatment of osteonecrosis of the femoral head (ONFH), while miR‐135b was shown to play an important role in the development of ONFH. In this study, we investigated the effects of concomitant administration of exosomes and miR‐135b on the treatment of ONFH. A rat mode of ONFH was established. TEM, Western blotting and nanoparticle analysis were used to characterize the exosomes collected from human‐induced pluripotent stem cell–derived mesenchymal stem cells (hiPS‐MSC‐Exos). Micro‐CT was used to observe the trabecular bone structure of the femoral head. Real‐time PCR, Western blot analysis, IHC assay, TUNEL assay, MTT assay and flow cytometry were performed to detect the effect of hiPS‐MSC‐Exos and miR‐135b on cell apoptosis and the expression of PDCD4/caspase‐3/OCN. Moreover, computational analysis and luciferase assay were conducted to identify the regulatory relationship between PDCD4 mRNA and miR‐135b. The hiPS‐MSC‐Exos collected in this study displayed a spheroidal morphology with sizes ranging from 20 to 100 nm and a mean concentration of 1 × 10¹² particles/mL. During the treatment of ONFH, the administration of hiPS‐MSC‐Exos and miR‐135b alleviated the magnitude of bone loss. Furthermore, the treatment of MG‐63 and U‐2 cells with hiPS‐MSC‐Exos and miR‐135b could promote cell proliferation and inhibit cell apoptosis. Moreover, PDCD4 mRNA was identified as a virtual target gene of miR‐135b. HiPS‐MSC‐Exos exerted positive effects during the treatment of ONFH, and the administration of miR‐135b could reinforce the effect of hiPS‐MSC‐Exos by inhibiting the expression of PDCD4.

中文翻译：

---

给予源自 MSCs 的 mircoRNA-135b 增强的外泌体可改善糖皮质激素诱导的大鼠股骨头坏死 (ONFH)

发现外泌体在治疗股骨头坏死（ONFH）中发挥治疗作用，而miR-135b被证明在ONFH的发展中起重要作用。在这项研究中，我们研究了同时施用外泌体和 miR-135b 对 ONFH 治疗的影响。建立ONFH大鼠模式。TEM、蛋白质印迹和纳米颗粒分析用于表征从人类诱导的多能干细胞衍生的间充质干细胞 (hiPS-MSC-Exos) 收集的外泌体。Micro-CT用于观察股骨头骨小梁结构。采用实时荧光定量PCR、Western blot分析、IHC分析、TUNEL分析、MTT分析和流式细胞术检测hiPS-MSC-Exos和miR-135b对细胞凋亡和PDCD4/caspase-3/OCN表达的影响. 而且，进行计算分析和荧光素酶测定以确定PDCD4 mRNA和miR-135b之间的调节关系。本研究中收集的 hiPS-MSC-Exos 呈球形，尺寸范围为 20 至 100 nm，平均浓度为 1 × 10¹²颗粒/mL。在 ONFH 治疗期间，hiPS-MSC-Exos 和 miR-135b 的给药减轻了骨丢失的程度。此外，用 hiPS-MSC-Exos 和 miR-135b 处理 MG-63 和 U-2 细胞可以促进细胞增殖并抑制细胞凋亡。此外，PDCD4 mRNA 被鉴定为 miR-135b 的虚拟靶基因。HiPS-MSC-Exos 在 ONFH 治疗过程中发挥了积极作用，miR-135b 的给药可通过抑制 PDCD4 的表达来增强 hiPS-MSC-Exos 的作用。