Neural Progenitor Grafting for Restorative Stroke Therapy

描述（由申请人提供）：本提案的总体目标是确定人类胚胎干细胞（hESC）或诱导多能干细胞（iPSC）衍生的神经祖细胞（NPC）移植在多大程度上改善实验性中风后的恢复，并开始解决最终人类中风治疗所需的关键安全性和有效性问题。hESCs作为再生治疗的npc来源具有许多优点，如易于获得的供应、巨大的分化潜力和易于基因操作。iPSCs提供了自体移植的额外优势，避免了免疫抑制的需要。然而，对于任何一种来源，实现中枢神经系统再生所需的理想供体细胞类型和发育状态都知之甚少。鼻咽癌移植是否能恢复中风后的功能，以及其可能的机制也是未知的。我们已经开发了从hESCs衍生的特定NPC群体的富集方法，并使用从人成纤维细胞衍生的iPSCs生成了NPC和多种神经元亚型。利用这些技术，我们提出验证以下假设：1)纯化的多能性npc （mpnpc）和神经元限制性前体（NRPs）群体可以通过iPSCs从hESCs或人类体细胞中获得。这些群体在移植到完整或受伤的成年大鼠脑后的迁移、分化和整合方面存在差异；2)实验性脑卒中后移植mpNPCs或nrp可通过神经元替代或内源性NPCs刺激修复直接促进功能恢复。具体目标1和2是使用基于启动子的报告子或基于细胞表面抗原的选择纯化和表征特定的NPC群体。目的3是研究这些NPC群体在移植到成年大鼠脑的神经源性和非神经源性区域后的行为，目的4是研究hESC和iPSC（人和大鼠）来源的NPC移植物对实验性卒中后恢复的影响。这些目标的进展将提高我们对移植物因子如何影响hESC或ipsc衍生的npc修复损伤脑和促进实验性中风后恢复能力的认识，并将深入了解这些疗法尚未开发的修复潜力和可能的风险。

DESCRIPTION (provided by applicant): The overall goals of this proposal are to determine the extent to which human embryonic stem cell (hESC)- or induced pluripotent stem cell (iPSC)-derived neural progenitor cell (NPC) grafts improve recovery after experimental stroke, and to begin addressing the critical safety and efficacy questions necessary for eventual human stroke therapy. hESCs offer many advantages as a source of NPCs for regenerative therapy, such as a readily available supply, vast differentiation potential and ease of genetic manipulation. iPSCs offer the added advantage of autologous grafting that obviates the need for immunosuppression. For either source, however, the ideal donor cell types and developmental states required to achieve CNS regeneration are poorly understood. Whether NPC grafting restores function after stroke and the mechanisms by which it might do so also are unknown. We have developed methods to enrich for specific NPC populations derived from hESCs, and have generated NPCs and multiple neuronal subtypes using iPSCs derived from human fibroblasts. Using these techniques, we propose to test the following hypotheses: 1) purified populations of multipotent NPCs (mpNPCs) and neuronal restricted precursors (NRPs) can be derived from hESCs or from human somatic cells via iPSCs. These populations will differ in their migration, differentiation and integration after transplantation into the intact or injured adult rat brain; and 2) grafting of mpNPCs or NRPs after experimental stroke will enhance functional recovery directly by neuronal replacement or by stimulating repair via endogenous NPCs. Specific Aims 1 and 2 are to purify and characterize specific NPC populations using promoter-based reporter or cell surface antigen-based selection. Aim 3 is to examine the behavior of these NPC populations after grafting into neurogenic and non-neurogenic regions of the adult rat brain, and Aim 4 is to examine the influence of hESC- and iPSC (human and rat)-derived NPC grafts on recovery after experimental stroke. Progress in these aims will advance our knowledge of how graft factors influence the capacity of hESC- or iPSC-derived NPCs to repair the injured brain and promote recovery after experimental stroke, and will provide insight into the untapped reparative potential and possible risks of these therapies. PUBLIC HEALTH RELEVANCE: Stroke is a common and potentially devastating neurological disorder with no proven regenerative therapies. This proposal aims to derive neural stem cells (NSCs) from human embryonic stem cells or reprogramming of human adult skin cells, and to use a stroke model to identify the optimal NSC grafts for brain reparative stroke therapy. Progress in this area offers advances toward novel cell-based restorative therapies for stroke and other brain insults.