Directed In Vivo Differentiation of Neural Stem Cells for Repair of Brain Lesion

产品说明：神经干细胞或神经祖细胞移植作为一种促进组织再生和重建创伤性脑损伤的有希望的策略，越来越多的人提出来。然而，移植后对人神经干/祖细胞（hNSCs）分化的控制差、移植细胞在病变部位的低存活率和整合严重限制了基于细胞的治疗的成功。本研究的目的是开发一种纳米颗粒介导的转录激活方法，以指导hNSCs在体内分化为功能性神经元和少突胶质细胞。这种新的方法将提供更好的控制和更高的效率的存活，分化，成熟和整合的功能细胞在体内。我们将证明这种方法的优点，通过移植转录激活的hNSCs在定制的透明质酸水凝胶到创伤性脑损伤（TBI）的大鼠模型，并通过检查细胞的存活，分化和整合的移植细胞，和组织再生的结果在病变部位。基于最近的发现，即通过病毒转染过表达关键转录因子诱导功能性神经元的快速和有效产生，以及能够介导干细胞和祖细胞中有效转基因表达的可生物降解的纳米颗粒转染方法，我们计划检验阶段特异性转录因子神经生成素2（Ngn 2）的瞬时表达是否与细胞增殖有关的假设。和少突胶质细胞转录因子Olig 2将促进它们在体内分别向功能性神经元和少突胶质细胞分化。本研究的主要目的是：（1）建立一种高效的纳米颗粒转染hiPSC源性神经干细胞，并研究Ngn 2和Olig 2表达对神经元和少突胶质细胞分化的影响;（2）证明源自hiPSC的Ngn 2转染和Olig 2转染的hNSC在体内的定向分化，以及水凝胶递送在促进hNSC存活、分化、和转染细胞的成熟以及在大鼠TBI模型中增强组织再生。这项研究不仅将促进我们对转录因子激活在体内调节移植的hiPSC衍生的NSC的存活、分化和成熟的理解，而且还将为治疗广泛的创伤性损伤和神经退行性疾病的脑组织再生提供新的策略。这种新的纳米颗粒方法与具有确定组成的原位形成水凝胶一起对于临床转化是高度期望的。

DESCRIPTION: Transplantation of neural stem or progenitor cells has been increasing proposed as a promising strategy to promote tissue regeneration and reconstruct the lesion cavity of TBI. However, poor control over the differentiation of human neural stem/progenitor cells (hNSCs) following transplantation, low survival and integration of the transplanted cells at the lesion site has severely limited the success of cell-based therapies. The objective of this study is to develop a nanoparticle-mediated transcription activation approach to direct the differentiation of hNSCs in vivo into functional neurons and oligodendrocytes. This new method will afford better control and higher efficiency of the survival, differentiation, maturation, and integration of the functional cells in vivo. We will demonstrate the advantages of this approach by transplanting transcriptionally activated hNSCs in a tailored hyaluronic acid hydrogel into a rat model of traumatic brain injury (TBI), and by examining cell survival, differentiation and integration of the transplanted cells, and tissue regeneration outcomes at the lesion site. Based on recent findings that over-expression of key transcriptional factors by viral transfection induces rapid and efficient production of functional neurons, and biodegradable nanoparticle transfection method capable of mediating efficient transgene expression in stem and progenitor cells, we plan to test the hypothesis that transient expression of stage-specific transcriptional factor neurogenin 2 (Ngn2) and oligodendrocyte transcription factor Olig2 in human induced pluripotent stem cell (hiPSC)-derived NSCs prior to transplantation will promote their in vivo differentiation towards functional neurons and oligodendrocytes, respectively. We will pursue the following specific aims in this exploratory grant: (1) to establish a highly effective nanoparticles for transfection of hiPSC-derived NSCs by plasmids encoding transcription factor Ngn2 and Olig2, respectively, and to investigate the effect of Ngn2 and Olig2 expression on neuronal and oligodendrocyte differentiation, respectively; (2) to demonstrate the directed differentiation of Ngn2-transfected and Olig2-transfected hNSCs derived from hiPSCs in vivo, and the advantage of hydrogel delivery in promoting the survival, differentiation, and maturation of the transfected cells and in enhancing tissue regeneration in a rat TBI model. This study will not only advance our understanding of transcription factor activation in regulating the survival, differentiation, and maturation of transplanted hiPSC-derived NSCs in vivo, but also offer new strategies for brain tissue regeneration in treating a wide range of traumatic injuries and neurodegenerative diseases. This new nanoparticle method together with the in situ forming hydrogels with defined compositions is highly desirable for clinical translation.