Department of Gastrointestinal Surgery, Department of General Surgery, The Sixth Affiliated Hospital, Sun Yat-Sen University, 26 Yuancun Er Heng Rd. Guangzhou, Guangzhou, China.
Department of Gastrointestinal Surgery, Department of General Surgery, Guangdong Provincial Key Laboratory of Colorectal and Pelvic Floor Diseases, The Sixth Affiliated Hospital, Sun Yat-Sen University, Guangzhou, China.
J Gastroenterol. 2024 Dec;59(12):1092-1106. doi: 10.1007/s00535-024-02152-5. Epub 2024 Sep 21.
Intestinal fibrosis is one of the most frequent and severe complications of Crohn's disease. Accumulating studies have reported that adipose mesenchymal stem cell-derived small extracellular vesicles (AMSC-sEVs) could alleviate renal fibrosis, hepatic fibrosis, etc., while their potential for treating intestinal fibrosis remains uncertain. Therefore, this study aims to determine the therapeutic effects of AMSC-sEVs on intestinal fibrosis and identify the mechanisms underlying these effects.
AMSC-sEVs were characterized using transmission electron microscopy, nanoparticle tracking analysis, and western blot. Whether AMSC-sEVs exert antifibrotic effects was investigated in two different murine models of intestinal fibrosis. Besides, AMSC-sEVs were co-cultured with primary human fibroblasts and CCD18co during transforming growth factor (TGF)-β1 stimulation. Label-free proteomics and rescue experiments were performed to identify candidate molecules in AMSC-sEVs. Transcriptome sequencing revealed changes in mRNA levels among different groups. Lastly, proteins related to relevant signaling pathways were identified by western blotting, and their expression and activation status were assessed.
AMSC-sEVs positively expressed CD63 and Alix and presented a classical "rim of a cup" and granule shape with approximately 43-100 nm diameter. AMSCs significantly alleviated intestinal fibrosis through secreted sEVs in vitro and in vivo. The milk fat globule-EGF factor 8 (MFGE8) was stably enriched in AMSC-sEVs and was an active compound contributing to the treatment of intestinal fibrosis by AMSCs. Mechanistically, AMSC-sEV-based therapies attenuated intestinal fibrosis by inhibiting the FAK/Akt signaling pathway.
MFGE8-containing AMSC-sEVs attenuate intestinal fibrosis, partly through FAK/Akt pathway inhibition.
肠纤维化是克罗恩病最常见和最严重的并发症之一。越来越多的研究报道脂肪间充质干细胞衍生的小细胞外囊泡（AMSC-sEVs）可以缓解肾纤维化、肝纤维化等，但其治疗肠纤维化的潜力尚不确定。因此，本研究旨在确定 AMSC-sEVs 对肠纤维化的治疗效果，并确定其作用机制。
采用透射电子显微镜、纳米颗粒跟踪分析和 Western blot 对 AMSC-sEVs 进行表征。在两种不同的肠纤维化小鼠模型中研究 AMSC-sEVs 是否具有抗纤维化作用。此外，在 TGF-β1 刺激下，将 AMSC-sEVs 与原代人成纤维细胞和 CCD18co 共培养。进行无标记蛋白质组学和拯救实验，以鉴定 AMSC-sEVs 中的候选分子。转录组测序揭示了不同组之间 mRNA 水平的变化。最后，通过 Western blot 鉴定与相关信号通路相关的蛋白质，并评估其表达和激活状态。
AMSC-sEVs 阳性表达 CD63 和 Alix，呈典型的“杯缘”和颗粒状，直径约为 43-100nm。AMSCs 通过体外和体内分泌的 sEVs 显著缓解肠纤维化。乳脂肪球表皮生长因子 8（MFGE8）在 AMSC-sEVs 中稳定富集，是 AMSCs 治疗肠纤维化的活性化合物。在机制上，基于 AMSC-sEV 的治疗通过抑制 FAK/Akt 信号通路来减轻肠纤维化。
含 MFGE8 的 AMSC-sEVs 通过抑制 FAK/Akt 信号通路减轻肠纤维化。
