MSCs来源exosomes调控巨噬细胞极化在炎症性肠病治疗中的作用及机制研究

Inflammatory bowel disease (IBD) is still lacking in effective management modalities and looking for novel treatment options is of great importance. Our pilot study showed that exosomes derived from mesenchymal stem cells (MSCs-Exos) could reduce bowel inflammation of IBD effectively, yet the reduction of inflammation disappeared when macrophage were deleted from mice model of IBD. Additionally, our function tests showed that MSCs-Exos could induce macrophage M2 polarization. Therefore, we hypothesized that MSCs-Exos might emerge as an effective treatment for IBD via polarizing M2 macrophage. Firstly, we are planning to verify the significance of macrophage mediated effectiveness of MSCs-Exos in the treatment of IBD using mice models. Secondly, the regulation of macrophage polarization by MSCs-Exos will be assessed via in vitro experiments. Then, protein mass spectrometry and RNA-Seq will be used to analyze the MSCs-Exos protein and response mechanisms of macrophage respectively. Following that, the key molecules of MSCs-Exos mediated macrophage polarization are further identified by CRISPR and gene rescue experiments etc. Lastly, the significance of key molecules in the treatment of IBD will be validated using clinical samples of IBD patients as well as mice models of IBD. This study will provide theoretical basis for clinical application of MSCs-Exos in the treatment of IBD.

炎症性肠病（IBD）的疗效迄今仍不理想，亟需探索新的有效治疗手段。我们前期实验发现输注间充质干细胞来源外泌体（MSCs-Exos）可减轻IBD小鼠肠道炎症，但对巨噬细胞缺失小鼠效果欠佳。功能实验显示MSCs-Exos可促进巨噬细胞M2型极化。因此，我们提出“MSCs-Exos通过调控巨噬细胞极化治疗IBD”的科学假说。本项目拟首先利用小鼠模型证实MSCs-Exos对IBD的治疗价值，并明确巨噬细胞介导MSCs-Exos作用的重要性。其次，通过体内外功能实验探讨MSCs-Exos调控巨噬细胞极化的生物学效应。然后，利用蛋白质谱及表达谱测序分别检测MSCs-Exos蛋白和巨噬细胞的应答通路，结合CRISPR、基因回复等技术锁定调控巨噬细胞极化的关键分子。最后，经临床标本和小鼠模型进一步验证MSCs-Exos负载关键分子的作用。本项目将为MSCs-Exos治疗IBD的临床应用提供坚实的实验基础。

炎症性肠病（IBD）的疗效迄今仍不理想，亟需探索新的有效治疗手段。我们研究发现，输注骨髓来源的间充质干细胞外泌体（MSC-Exos）对多种小鼠IBD模型具有治疗作用。MSC-Exos治疗能够抑制小鼠肠道的炎症反应，保护肠道粘膜屏障的完整性，并且诱导巨噬细胞向M2型极化。机制上，我们发现输注的MSC-Exos主要作用于肠道的巨噬细胞，能够增强巨噬细胞对炎症刺激的抵抗，促进巨噬细胞分泌IL-10，从而发挥对IBD的治疗作用。去除巨噬细胞后MSC-Exos对小鼠IBD的治疗作用消失。我们通过蛋白质谱分析发现，MSC-Exos中含有多种参与抗炎作用相关通路的蛋白。其中，金属硫蛋白-2在MSC-Exos抑制炎症反应中发挥重要作用。本项目将为MSCs-Exos治疗IBD的临床应用提供坚实的实验基础。