Directed Differentiation of Stem Cell Transplants into Myelinating Glia

干细胞移植定向分化为髓鞘神经胶质细胞

• 批准号: 8457408
• 负责人: Stephanie Kristin Seidlits
• 金额: $ 5.22万
• 依托单位: NORTHWESTERN UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2012
• 资助国家: 美国
• 起止时间: 2012-12-01 至 2014-11-30
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8457408
• 关键词: Academia; Address; Affect; Architecture; Astrocytes; Axon; Back Injuries; Binding; Biocompatible Materials; Biological; Biomimetics; Cell Culture Techniques; Cell Survival; Cell Transplantation; Cell Transplants; Cell physiology; Cells; Clinical; Complex; Cues; Development; Educational process of instructing; Educational workshop; Embryo; Engineering; Environment; Exhibits; Fluorescence; Gene Delivery; Gene Expression; Goals; Growth Factor; Histological Techniques; Human; Image; Imagery; Implant; Inflammation; Injection of therapeutic agent; Injury; Interleukin-2; Knowledge; Laboratories; Lesion; Libraries; Life; Luciferases; Measures; Mediating; Mentors; Methods; Monitor; Natural regeneration; Neuroglia; Neurotrophin 3; Nuclear Pore Complex; Oligodendroglia; Output; Population; Proteins; Protocols documentation; Recovery of Function; Regenerative Medicine; Reporter; Reporting; Research; Screening procedure; Signal Pathway; Signal Transduction; Site; Spinal cord injury; Staging; Stem cell transplant; Stem cells; Students; System; Systems Biology; Techniques; Technology; Therapeutic; Time; Tissues; Training; Transplantation; Writing; axon growth; axon guidance; axon regeneration; career; design; extracellular; fetal; functional improvement; human stem cells; implantation; in vivo; in vivo Model; injury and repair; migration; myelination; nerve stem cell; neurotrophic factor; novel; novel strategies; progenitor; red fluorescent protein; remyelination; response; scaffold; stem; success; symposium; tool; transcription factor; vector

DESCRIPTION (provided by applicant): Oligodendrocyte replacement and remyelination are essential to functional recovery after spinal cord injury (SCI). Therapeutic delivery of stem or progenitor cells is a promising tool as these cells produce factors that reduce inflammation, enhance survival of existing oligodendrocytes and have the capacity to differentiate into new oligodendrocytes. However, the local environment that develops after SCI does not promote differentiation into mature cells capable of functionally integrating with the host tisue and myelinating regenerated axons. The proposed research will develop a strategy to alter this local environment to direct differentiation of human fetal-derived neural stem cells (hCNS-SCns) into myelinating oligodendrocytes. The key factors required to promote oligodendrocyte differentiation are largely unknown and current protocols are inefficient. In Aim 1, we wil use a high-throughput array of transcription factor (TF) activity to identify these key factors within controlled microenvironments. As the output of complex intracellular signaling networks, TF activity represents the functional state of a cell (e.g., stage of differentiation). Using this novl systems biology approach, we have the ability to quantify the functional cell response to various extracellular cues and identify cues which most efficiently activate the signaling pathways that induce oligodendrocyte differentiation. Dynamic changes in TF activation will be monitored in live hCNS-SCns cultured in 3D microenvironments tuned to present combinations of defined extracellular cues simultaneously. Effects of these cues will be systematically evaluated to identify conditions that best direct oligodendrocyte differentiation. In Aim 2, hCNS-SCns will be transplanted to an in vivo model of SCI within microenvironments displaying cues found to maximize oligodendroctye differentiation. Microenvironments will be incorporated into a biomaterial platform previously developed by the Shea laboratory. These bridge scaffolds exhibit a microarchitecture that promotes axon guidance across the injury and back into host tissue. Scaffold-mediated delivery of genes encoding for neurotrophic factors further enhances axon growth. This proposal builds upon this success by adding a component to replace myelinating oligodendrocytes after SCI. In addition, Aim 2 will investigate how the stage of differentiation at the time of implantation affects the myelination capacity of hCNS- SCns. Results will significantly advance the clinical potential of cell transplantation for SCI repair. I addition, the proposed training plan will more than adequately prepare the felow for a successful career in academia. The fellow will gain expertise in human stem cell cultures, in vivo models of SCI and methods to genetically modify living cells as a tool to understand biological mechanisms. Furthermore, she will apply this knowledge to develop novel strategies for regenerative medicine. The fellow also has significant opportunities for professional development through the proposed training plan, including teaching and writing workshops, attending scientific conferences and mentoring students. PUBLIC HEALTH RELEVANCE: Replacement of functional oligodendrocytes and remyelination of axons through cell transplantation is a promising strategy for spinal cord injury repair. The proposed research aims to: 1) identify environmental cues that efficiently direct oligodendrocyte differentiation using a novel systems biology approach and 2) deliver human embryonic-derived stem cells in vivo within microenvironment carriers designed to present these cues.

描述(申请人提供)：少突胶质细胞替代和重新髓鞘形成是脊髓损伤(SCI)后功能恢复的关键。干细胞或祖细胞的治疗性输送是一种很有前途的工具，因为这些细胞产生的因子可以减少炎症，提高现有少突胶质细胞的存活率，并具有分化为新的少突胶质细胞的能力。然而，脊髓损伤后形成的局部环境并不促进分化为能够与宿主组织功能整合并使再生轴突髓鞘形成的成熟细胞。这项拟议的研究将开发一种策略，改变这种局部环境，直接将人胎儿来源的神经干细胞(hCNS-SCN)分化为髓鞘少突胶质细胞。促进少突胶质细胞分化所需的关键因素在很大程度上是未知的，目前的方案效率低下。在目标1中，我们将使用高通量的转录因子(TF)活性阵列来识别受控微环境中的这些关键因子。作为复杂的细胞内信号网络的输出，转铁蛋白活性代表了细胞的功能状态(如分化阶段)。使用这种新的系统生物学方法，我们有能力量化功能细胞对各种细胞外信号的反应，并识别最有效地激活诱导少突胶质细胞分化的信号通路的信号通路。在3D微环境中培养的活体hCNS-SCN中，TF激活的动态变化将被监测，以同时呈现已定义的细胞外线索的组合。这些信号的影响将被系统地评估，以确定最佳的引导少突胶质细胞分化的条件。在目标2中，hCNS-SCNS将被移植到脊髓损伤的体内模型中，在微环境中显示发现的最大限度地促进少突胶质细胞分化的线索。微环境将被纳入之前由SHEA实验室开发的生物材料平台。这些桥支架展示了一种微结构，促进轴突引导穿过损伤并回到宿主组织。支架介导的神经营养因子编码基因的传递进一步促进轴突生长。这一建议是在这一成功的基础上，通过增加一种成分来取代脊髓损伤后髓鞘少突胶质细胞。此外，目标2将研究植入时的分化阶段如何影响hCNS-SCN的髓鞘形成能力。结果将显著提高细胞移植修复脊髓损伤的临床潜力。此外，拟议的培训计划将为研究员在学术界的成功职业生涯做好充分准备。这位研究员将获得人类干细胞培养、脊髓损伤体内模型以及通过基因修饰活细胞作为了解生物学机制的工具的方法方面的专业知识。此外，她将应用这一知识来开发再生医学的新策略。通过拟议的培训计划，该研究员还获得了重要的专业发展机会，包括教学和写作研讨会、参加科学会议和指导学生。 公共卫生相关性：通过细胞移植替代功能性少突胶质细胞和轴突重新髓鞘形成是脊髓损伤修复的一种很有前途的策略。这项拟议的研究旨在：1)利用一种新的系统生物学方法，识别有效地指导少突胶质细胞分化的环境线索；2)在为呈现这些线索而设计的微环境载体中，体内传递人类胚胎干细胞。