AhR对于间充质干细胞体内动力学的影响及其机制研究

Cell therapy, especially mesenchymal stem cells (MSCs), has become one of the most promising stars in drug development. However, the knowledge about MSC is very limited, especially the regulatory mechanisms of its elimination and distribution process in vivo. AhR is critical in the regulation of NK cell and macrophage functions, while the NK cells is believed to be the key pathway for the elimination of MSC. Therefore, we speculate environmental factors and drugs may influence MSC elimination and disposition through AhR, which has great impacts on the variability of MSC’s therapy efficacy. The key point of this project is to investigate if AhR could influence MSC elimination and disposition through immune system. Luciferase labeling technique and QPCR quantification will be employed to trace MSC’s cellular pharmacokinetic process in vivo. With the help of AhR knockout animal model, AhR’s contribution to MSC elimination, proliferation and homing will be clarified. After the investigation of the interactions among MSC, NK cell and macrophage, we can reveal the beneath mechanisms of AhR and MSC cellular kinetics. A PBPK model to describe the elimination and disposition of MSC will be developed based on the valuable information obtained above. It will become feasible to build connections between MSC cellular fate (pharmacokinetics) and its efficacy, which will increase its clinical efficacy and decrease potential drug safety issues eventually.

细胞治疗已经成为创新药物研发中最具前景的领域之一，尤其是间充质干细胞（MSC）。但是人们对MSC认识有限，尤其是它的体内清除和分布的调控机制。由于AhR受体对于免疫系统的NK和巨噬细胞功能有比较明确的调节作用，而NK细胞又是MSC清除的主要途径，我们推测外界因素可能通过AhR影响MSC的体内动力学，是MSC疗效个体差异的重要来源之一。本课题的核心是研究AhR核受体的免疫调节功能对MSC清除和分布的影响。首先拟通过luciferase和QPCR相结合的双重谱系追踪方法，定量阐述MSC在机体的细胞动力学过程。在此基础上，通过AhR敲除动物模型，考察外界因素对于MSC体内清除，增殖分化和归巢等处置途径的影响。探索MSC，NK和巨噬细胞相互关系，量化阐述AhR功能状态影响MSC体内药代的分子机制。建立MSC细胞在体清除和分布的生理动力学模型，阐明MSC进入机体之后的动态分布和细胞疗效之间的关系。

细胞治疗已经成为创新药物研发中最具前景的领域之一，尤其是间充质干细胞（MSC）。但是人们对MSC认识有限，尤其是它的体内清除和分布的调控机制。.本课题首先通过荧光标记和QPCR相结合的双重谱系追踪方法，定量阐述MSC在正常和疾病状态下机体的细胞动力学特征。在此基础上，通过AhR诱导或抑制考察对于MSC体内清除，增殖分化和归巢等处置途径的影响。量化阐述AhR功能状态影响MSC体内药代和药效的分子机制。阐明MSC进入机体之后的动态分布和细胞疗效之间的关系。.结果显示MSC在体内分布主要集中于肺脏和肝脏，并且在肺脏中存在二次分布现象，而血管扩张剂可以提高MSC的体内暴露量。此外，在急性肝损伤状态下，MSC的PK存在与药效不一致的现象，这归于病理状态下脏器微环境如淤血等的影响。发现经过改善微环境后可以提高MSC的脏器暴露。同时，揭示通过抑制“AhR-铁死亡”轴，可以改善微环境的氧化应激和炎症反应，能够提升移植进入体内的治疗细胞（hMSC）的暴露量，并显著提升hMSCs治疗效果。.本课题建立了MSC等体细胞体内药物命运的研究范式，是中国首次系统的体细胞药代动力学研究；国际上首次系统阐述了MSC在不同种属动物和不同疾病对于MSC的PK行为的影响；初步阐明了AhR对于MSC药代动力学的影响机制，可以支持提高细胞产品的临床疗效，降低风险。