Department of Oncology, 920th Hospital of Joint Logistics Support Force, Teaching Hospital of Kunming Medical University, 212 Daguan Road, Kunming, 650032, China.
Department of Geriatrics, 920th Hospital of Joint Logistics Support Force, Teaching Hospital of Kunming Medical University, Kunming, 650032, China.
J Exp Clin Cancer Res. 2022 Apr 7;41(1):128. doi: 10.1186/s13046-022-02351-z.
Radiation-induced lung fibrosis (RILF) is a common complication of thoracic radiotherapy. Alveolar epithelial cells play a crucial role in lung fibrosis via epithelial-mesenchymal transition (EMT). Exosomes derived from mesenchymal stem cells own the beneficial properties to repair and regeneration of damaged tissues, however the underlying mechanisms remain poorly understood.
Mouse mesenchymal stem cells-derived exosomes (mMSCs-Exo) were isolated by differential centrifugation, and their protective effects were assessed in vivo and in vitro, respectively. EMT-associated proteins were measured via western blot assay and/or immunofluorescence staining. The miRNA expression was measured by microarray assay and qPCR. Furthermore, bioinformatics prediction with KEGG analysis, luciferase assay, and rescue experiments were performed to explore the molecular mechanism underlying miR-466f-3p.
mMSCs-Exos were efficiently isolated ranging from 90-150 nm with high expression of exosomal markers (CD63, TSG101, and CD9). mMSCs-Exos administration efficiently relieved radiation-induced lung injury with less collagen deposition and lower levels of IL-1β and IL-6. Meanwhile, in vitro results showed mMSCs-Exos treatment obviously reversed EMT process induced by radiation. Among enriched miRNA cargo in exosomes, miR-466f-3p was primarily responsible for the protective effects via inhibition of AKT/GSK3β pathway. Our mechanistic study further demonstrated that c-MET was the direct target of miR-466f-3p, whose restoration partially abrogated mMSCs-Exo-mediated inhibition in both EMT process and AKT/GSK3β signaling activity induced by radiation.
Our findings indicated that exosomal miR-466f-3p derived from mMSCs may possess anti-fibrotic properties and prevent radiation-induced EMT through inhibition of AKT/GSK3β via c-MET, providing a promising therapeutic modality for radiation-induced lung fibrosis.
放射性肺纤维化（RILF）是胸部放射治疗的常见并发症。肺泡上皮细胞通过上皮-间充质转化（EMT）在肺纤维化中发挥关键作用。间充质干细胞衍生的外泌体（mMSCs-Exo）具有修复和再生受损组织的有益特性，但其潜在机制仍知之甚少。
通过差速离心法分离小鼠间充质干细胞衍生的外泌体（mMSCs-Exo），分别在体内和体外评估其保护作用。通过 Western blot 检测和/或免疫荧光染色检测 EMT 相关蛋白。通过微阵列分析和 qPCR 测量 miRNA 表达。此外，通过生物信息学预测、KEGG 分析、荧光素酶报告基因实验和挽救实验，探讨 miR-466f-3p 的分子机制。
mMSCs-Exos 被有效分离，大小范围为 90-150nm，高表达外泌体标记物（CD63、TSG101 和 CD9）。mMSCs-Exos 给药可有效缓解放射性肺损伤，减少胶原沉积和降低 IL-1β 和 IL-6 水平。同时，体外结果表明 mMSCs-Exos 处理可明显逆转辐射诱导的 EMT 过程。在富含外泌体的 miRNA cargos 中，miR-466f-3p 主要通过抑制 AKT/GSK3β 通路发挥保护作用。我们的机制研究进一步表明，c-MET 是 miR-466f-3p 的直接靶点，其恢复部分消除了 mMSCs-Exo 介导的辐射诱导的 EMT 过程和 AKT/GSK3β 信号活性抑制。
我们的研究结果表明，mMSCs 衍生的外泌体 miR-466f-3p 可能具有抗纤维化特性，并通过抑制 AKT/GSK3β 途径预防辐射诱导的 EMT，为放射性肺纤维化提供了一种有前途的治疗方法。
