Objective: To explore the repair effect and its related mechanism of exosomes derived from embryonic stem cell-induced mesenchymal stromal cells (ESC-MSC) on radiation-induced lymphocyte damage.
Methods: A culture system for differentiating embryonic stem cells (ESC) into ESC-MSC was established, with the induced cells identified by flow cytometry and morphological methods. ESC-MSC-derived exosomes (ESC-MSC-Exo) were isolated and purified, followed by identification via electron microscopy, nanoparticle tracking analysis (NTA), and Western blot. Then they were compared with human bone marrow mesenchymal stromal cell-derived exosomes (BM MSC-Exo) to observe their similarities and differences. Lymphocytes from healthy human were isolated and irradiated with 4 Gy 60Co γ-rays, then they were co-cultured with ESC-MSC-Exo or BM MSC-Exo for 48 hours. Apoptosis, DNA fragmentation, reactive oxygen species (ROS) production, and mitochondrial membrane potential changes were detected to compare the therapeutic efficacy differences between the two types of exosomes and explore the repair effect and related mechanism of ESC-MSC-Exo on radiation-induced lymphocyte damage.
Results: Flow cytometry and morphological identification confirmed that ESC-MSC expressed mesenchymal stromal cell (MSC) surface markers and exhibited a spindle-shaped morphology. Electron microscopy observation showed ESC-MSC-Exo was cup-shaped or hemispherical with a concave side. Western blot verified the presence of exosomal marker proteins (TSG101, CD63, CD81), and NTA revealed uniform particle size with a peak of 153.6 nm. ESC-MSC-Exo alleviated radiation-induced lymphocyte apoptosis and DNA fragmentation, reduced ROS production, and improved radiation-induced mitochondrial membrane potential depolarization.
Conclusion: ESC-MSC-Exo can mitigate radiation-induced oxidative stress and reduce apoptosis in lymphocytes.
题目: 胚胎干细胞来源的间充质基质细胞外泌体对辐射淋巴细胞损伤的保护作用及相关机制研究.
目的: 探索胚胎干细胞诱导的间充质基质细胞来源外泌体对辐射导致淋巴细胞损伤的修复作用及相关机制.
方法: 建立胚胎干细胞（ESC）诱导分化间充质基质细胞（ESC-MSC）培养体系，并通过流式细胞术及形态学方法对诱导产生的细胞进行鉴定。分离纯化ESC-MSC外泌体（ESC-MSC-Exo），通过电镜观察、纳米示踪分析、蛋白免疫印迹检测对其进行鉴定，并将其与人骨髓MSC外泌体（BM MSC-Exo）进行对比，观察其异同。分离健康人外周血淋巴细胞，60Coγ 射线对其进行4 Gy照射，在培养体系中分别加入ESC-MSC-Exo、BM MSC-Exo共培养48 h，对其凋亡、DNA断裂、活性氧（ROS）产生、线粒体膜电位变化情况进行检测，对比两种外泌体疗效差异并探索ESC-MSC-Exo对辐射导致淋巴细胞损伤的修复作用及其相关机制.
结果: 通过流式细胞术及形态学鉴定证明ESC-MSC含有间充质基质细胞（MSC）表面标志且形态呈梭形。电镜观察示ESC-MSC-Exo呈茶托状或一侧凹陷的半球状；蛋白免疫印迹证明其含有外泌体标志性蛋白TSG101、CD63与CD81；纳米示踪分析结果显示，其颗粒大小均匀，峰值大小为153.6 nm。ESC-MSC-Exo能够改善辐射导致的淋巴细胞凋亡、DNA断裂，减少ROS产生，改善辐射诱导的线粒体膜电位下降.
结论: ESC-MSC-Exo能够改善辐射导致的淋巴细胞氧化应激，减少细胞凋亡.
Keywords: embryonic stem cell; mesenchymal stromal cell; exosome; radiation injury; oxidative stress.