Heterotypic Cell-Cell Interactions in Hybrid Human Stem Cell Microtissues during Neural Differentiation

 描述（由申请人提供）：尽管干细胞治疗脊髓损伤的结果很有希望，但间充质干细胞（MSC）提供了一种体内寿命短的中间解决方案。来源于人诱导多能干细胞（hiPSC）的神经祖细胞（NPC）为新型细胞疗法提供了替代来源，但hiPSC-NPC的植入需要改进。hiPSC-NPCs和MSCs微组织的形成可以上调MSCs和NPCs分泌营养因子，以及MSCs分泌抗凋亡和抗炎因子，促进NPC在损伤部位的植入。然而，MSC与hiPSC-NPC的复杂异型相互作用及其在神经发生期间的分泌活性尚未得到很好的理解。本研究的目的是构建由人MSC和hiPSC衍生的NPC组成的三维微组织，并研究异型细胞-细胞相互作用对体外神经分化过程中细胞外基质和营养因子分泌的影响。核心假设是， 异型细胞-细胞相互作用和内源性细胞外基质的分泌受MSC和hiPSC衍生的NPC的微组织结构调节，其促进营养因子部分和功能性神经分化。具体而言，提出了以下目标：1）目标1将测试的假设，即微组织的组成和结构差异调节营养因子的分泌，NPC分化，和氧化应激下的细胞存活。2)目的2将验证微组织结构调节内源性ECM分泌以刺激神经发生的假设。体外hiPSC神经微组织自组装被《科学》杂志的编辑选为2013年年度突破的亚军。通过他们独特的协调独裁信号的能力， 组织或微型器官样结构使人联想到体内的细胞组织，hiPSC及其衍生物提供了一个新的平台，以促进我们对用于治疗神经障碍的组织形态发生的理解。这个项目最具创新性的特点是， 通过构建具有可调结构的混合MSC-NPC微组织来实现基于微组织的神经分化，以实现增强的细胞功能和神经发生。如果成功，该研究将促进我们对hiPSC衍生的NPC和MSC在治疗神经损伤和神经发生期间细胞外微环境调节中的作用的理解。

 DESCRIPTION (provided by applicant): Despite the promising results from stem cell therapy in spinal cord injury, mesenchymal stem cells (MSCs) present an intermediate solution with short in vivo life span. Neural progenitor cells (NPCs) derived from human induced pluripotent stem cells (hiPSCs) provide an alternative source for novel cell therapy, but the engraftment of hiPSC-NPCs needs to be improved. The formation of microtissues of hiPSC-NPCs and MSCs could up-regulate the secretion of trophic factors from MSCs and NPCs, and the secretion of anti-apoptotic and anti-inflammatory factors from MSCs to enhance NPC engraftment at injury site. However, the complex heterotypic interactions of MSCs with hiPSC-NPCs and their secretory activities during neurogenesis have not been well understood.} The objective of this proposal is to construct 3-D microtissues composed of human MSCs and hiPSC-derived NPCs, and investigate the impact of heterotypic cell-cell interactions on the secretion of extracellular matrices and trophic factors during neural differentiation in vitro. The central hypothesis is that the heterotypic cell-cell interactions and the secretion of endogenous extracellular matrices are modulated by the structure of microtissues of MSCs and hiPSC- derived NPCs which promote trophic factor section and functional neural differentiation. Specifically, the following aims are proposed: 1) Aim 1 will test the hypothesis that the composition and structure of microtissues differentially regulates the secretion of trophic factors, NPC differentiation, and cell survival under oxidative stress. 2) Aim 2 will test the hypothesis that the structure of microtissues regulates the secretion of endogenous ECMs to stimulate neurogenesis. {Neural microtissue self-assembly from hiPSCs in vitro was chosen by Science's editors as a runner-up for 2013 Breakthrough of the Year. By their unique ability to coordinate the dictatorial signals and to form tissue or mini-organ like structures reminiscent of cell organization in vivo, hiPSCs and their derivatives provide a novel platform to advance our understanding on tissue morphogenesis for the treatment of neurological disorders. The most innovative feature of this project is to evaluate microtissue-based neural differentiation by fabricating hybrid MSC-NPC microtissues with tunable structure to achieve the enhanced cellular function and neurogenesis. If successful, the proposed study will advance our understanding on the actions of hiPSC-derived NPCs and MSCs in treating neural injury and on the modulation of extracellular microenvironment during neurogenesis.