姜黄素光敏化生成的ROS对脂肪源间充质干细胞增殖和分化的调控机理研究

Mesenchymal stem cells (MSCs) display enormous applicable prospect in clinical research and application because of its advantages including multi-lineage differentiation potential, low immunogenicity, convenience of obtaining, no moral and ethical issues, and so on. Clinical transplantation study of stem cells shows that precondition before transplantation could obviously enhance the transplanted stem cells’ ability of survival, homing and paracrine, thereby increase therapeutic effect of transplantation. Regulation of ROS level in the microenvironment of stem cell in vitro culture is one of the important strategies to precondition stem cells before transplantation. Our work team has been committing to the research on the regulation of the in vitro proliferation and differentiation of stem cells, and has obtained some exciting results in the promoting effect of nanomaterials on the maintenance of stem cells’ self-renewal. This project is based on the previous studies on the production of ROS induced by the photosensitization of Cur and the induced differentiation of stem cells, and plans to establish a controlled-produced system of ROS by photosensitization of Cur, and then explore the influence of changed ROS on the proliferation and differentiation of adipose-derived mesenchymal stem cell (ADMSCs). Also this project aims to confirm whether the ROS induced by photosensitization can serve as a way to precondition stem cell before stem cell transplantation therapy, and thereby establish a preconditioning platform for stem cell transplantation therapy on the basis of the photosensitizer-involved photosensitization.

间充质干细胞基于其多向分化潜能、免疫原性低、易于获取、无道德伦理问题等优点，在临床研究和应用中展现出巨大的前景。干细胞临床移植研究中发现干细胞移植前的预处理能够显著提高干细胞在受体体内的存活率、归巢能力和旁分泌功能，进而提高移植治疗的疗效。调控干细胞体外培养微环境中的ROS水平是干细胞移植前预处理的重要策略之一，本课题组近几年致力于调控干细胞体外扩增和诱导分化的研究工作，目前在纳米材料对干细胞干性维持和自我更新促进等方面的研究取得了较大的进展。本项目基于前期对姜黄素（Cur）光敏化能够诱导生成ROS的研究基础，拟构建基于Cur光敏化的ROS可控生成体系，并在该体系中考察脂肪源间充质干细的增殖和分化以及相关机制。本项目旨在通过探索光敏化途径诱导产生的ROS对干细胞增殖分化的影响，构建基于光敏剂光敏化的干细胞移植前预处理新策略。

间充质干细胞（Mesenchymal stem cell, MSCs）具有多向分化潜能、免疫原性低、易于获取、无道德伦理问题等优点，目前已经广泛应用于临床研究和应用中。但干细胞移植面临着存活率低、生物效应受到抑制等问题。ROS在干细胞的增殖、迁移和分化中扮演重要的角色。为了提高干细胞临床移植成功率，移植前干细胞的预处理能够显著提高干细胞的体内存活率、归巢能力和旁分泌功能，进而提高移植疗效。许多干细胞预处理策略都涉及到胞内ROS水平的调控。因此寻找一种简易有效的策略精准调控干细胞微环境ROS水平，对增加干细胞对移植人体环境的适应能力和提高临床干细胞移植治疗成功率具有非常重要的意义。.鉴于姜黄素是一种毒性低，代谢快的天然光敏剂，本项目旨在通过姜黄素光敏化调控ROS生成，进而研究ROS对间充质干细胞分化的影响。项目成功的分离培养了大鼠脂肪源间充质干细胞，然后对其进行了鉴定。然后项目借助460nm的LED灯板，通过考察单独光源辐照时间、单独姜黄素毒性、细胞对姜黄素吞噬情况、光敏化时间等因素初步确定了调控ROS生成的条件，即固定姜黄素浓度（2g/ml），姜黄素与干细胞孵育4小时开始辐照，光敏化时间控制在16min以内。在该条件下，姜黄素光敏化能够引起大鼠脂肪源间充质干细胞胞内ROS上升，同时不会影响细胞的生长。随后本项目考察了姜黄素光敏化介导的ROS生成预处理干细胞对其成骨和成脂分化的影响，结果表明，姜黄素光敏化预处理能够抑制干细胞朝着两种方向分化，相应的机制表明姜黄素光敏化引起了NOX和MEK1的降低，以及Oct4表达水平升高。该结果表明基于姜黄素光敏化的ROS生成能够抑制干细胞的分化，该研究为其他光敏剂应用于干细胞分化调控提供了一定的理论参考。