枸杞多糖经自噬提高人胎盘MSCs治疗肺纤维化的作用机制研究

Pulmonary fibrosis (PF) is a pulmonary interstitial disease caused by lung injury and inflammatory response. Pathogenesis is complicated. Clinically, there is still a lack of effective treatment to PF, and its mortality rate remains high. Some studies have demonstrated that mesenchymal stem cells (MSCs) as a novel treatment means has ideal therapeutic effects on pulmonary fibrosis. However, their therapeutic effect is restricted by pathological microenvironment of PF. Our recent work discovered that lycium barbarum polysaccharide (LBP) can promote the function of human placental MSCs of fetal origin (fPMSCs) to reverse the pathological progress of PF. Besides this, we clarified that LBP have the ability to elevate autophagy in pathological microenvironment associated with PF. Thus we hypothesize that LBP has the capability to influence biological functions of fPMSCs by regulating autophagy in PF pathological microenvironment, and elevate therapeutic potential of placental mesenchymal stem cells in pulmonary fibrosis models. Based on these results, the present project is designed to accomplish the following works: 1. to ascertain the regulatory relationship between LBP and autophagy of fPMSCs in PF pathological microenvironment; 2. to analyze the effects and mechanism of autophagy mediated by LBP in regulating biological functions of fPMSCs; 3. to clarify whether autophagy mediated by LBP influences the therapeutic effects of fPMSCs on PF and its potential principle. The results of these studies will partialy illustrate the functions and mechanism of fPMSCs’ properties regulated by LBP in a PF pathological microenvironment. This will provide the theoretical basis and experimental evidence for new strategies to optimize MSC treatment for PF.

肺纤维化（PF）是由肺损伤及过度炎症引起的间质性肺病，发病机制复杂，缺乏有效的疗法，死亡率逐年增加。研究表明，间充质干细胞（MSCs）是治疗PF最为理想的新手段，但PF病理微环境严重影响MSCs的疗效。我们前期发现：枸杞多糖可显著促进人胎盘胎儿来源MSCs（fPMSCs）对PF病理进程的逆转作用，并上调了PF病理微环境中fPMSCs自噬的发生。由此，我们推测枸杞多糖通过调控自噬影响PF病理微环境中fPMSCs的生物功能及其对PF的疗效。在此基础上，本项目拟完成：1.确定枸杞多糖对PF病理微环境中fPMSCs自噬发生的调控作用；2.研究枸杞多糖介导的自噬对fPMSCs生物功能的调节及分子机制；3.明晰枸杞多糖干预fPMSCs自噬对PF治疗的影响及机理。本项目的实施将部分明确枸杞多糖在优化fPMSCs治疗PF中的调控作用及分子机制，为提高MSCs治疗PF新策略的提出提供理论基础和实验依据。

肺纤维化是由肺损伤及过度炎症引起的间质性肺病，发病机制复杂，缺乏有效的疗法，死亡率逐年增加。研究表明，间充质干细胞（MSCs）是治疗肺纤维化最为理想的新手段，但肺纤维化病理微环境严重影响MSCs的疗效。我们前期发现：枸杞多糖可显著促进人胎盘胎儿来源MSCs（fPMSCs）对肺纤维化病理进程的逆转作用，并上调了肺纤维化病理微环境中fPMSCs自噬的发生。由此，我们推测枸杞多糖通过调控自噬影响肺纤维化病理微环境中fPMSCs的生物功能及其对肺纤维化的疗效。在此基础上，本项目拟完成：1.确定枸杞多糖对肺纤维化病理微环境中fPMSCs自噬发生的调控作用；2.研究枸杞多糖介导的自噬对fPMSCs生物功能的调节及分子机制；3.明晰枸杞多糖干预fPMSCs自噬对肺纤维化治疗的影响及机理。通过本项目的实施，我们证实枸杞多糖能够抑制由IFN-γ、TNF-α和TGF-β1营造的体外肺纤维化病理微环境介导的fPMSCs细胞凋亡，提高细胞的增殖能力。此外，枸杞多糖可以阻断IFN-γ、TNF-α和TGF-β1诱导的fPMSCs自噬流，进而达到抑制炎症微环境介导的fPMSCs细胞凋亡。尤为重要的是，我们发现RIP3与枸杞多糖调控炎症微环境中fPMSCs细胞自噬流密切相关，干预RIP3可有效逆转枸杞多糖对自噬流的调控作用。另一方面，我们发现肺纤维化相关炎症因子IL-1β具有下调fPMSCs组成型免疫抑制膜蛋白CD200的表达，减少阳性细胞比例的作用，弱化fPMSCs对巨噬细胞活化的免疫抑制作用。同时，IL-1β可诱导fPMSCs自噬的发生，且干预自噬阻断了IL-1β抑制fPMSCs CD200表达的作用，p38 MAPK信号通路又参与了IL-1β对fPMSCs自噬及CD200表达的调控。干预自噬的发生，可有效提高fPMSCs对肺纤维化模型小鼠的治疗作用。基于此，本项目的实施将部分明确枸杞多糖调控肺纤维化病理微环境中fPMSCs自噬和凋亡的作用机制，及自噬在炎症微环境中调控fPMSCs免疫调节功能的分子机制，为优化MSCs治疗肺纤维化的新策略提供了理论基础和实验依据。