Generating transplantable neurons by in vivo combinatorial screening of transcrip

通过体内转录组合筛选产生可移植神经元

• 批准号: 8508325
• 负责人: Mehmet Fatih Yanik
• 金额: $ 77.84万
• 依托单位: MASSACHUSETTS INSTITUTE OF TECHNOLOGY
• 依托单位国家: 美国
• 财政年份: 2011
• 资助国家: 美国
• 起止时间: 2011-09-30 至 2016-07-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8508325
• 关键词: Address; Adult; Affect; Animals; Biological; Biological Assay; Brain; Cell Lineage; Cell Transplants; Cells; Chemicals; Clinical; Clinical Trials; Cues; Degenerative Disorder; Disease; Epilepsy; Evaluation; Eye diseases; Genetic; Human; Huntington Disease; In Vitro; Individual; Laboratories; Mediating; Methodology; Modification; Molecular; Neuronal Injury; Neurons; Parkinson Disease; Physical therapy; Preparation; Process; RNA; Recovery of Function; Rodent; Signal Transduction; Site; Solutions; Staging; Stroke; Symptoms; Technology; Testing; Tissue Transplantation; Tissues; Transplantation; Xenograft procedure; aging population; cell type; combinatorial; fetal; functional improvement; high throughput screening; in vivo; induced pluripotent stem cell; innovation; neuronal growth; neuronal survival; nuclear reprogramming; release factor; research study; restoration; retina transplantation; screening; synaptogenesis; transcription factor

Problem: Neuronal injuries, degenerative diseases, and disorders such as Parkinson¿s and Huntington¿s diseases, epilepsy, and stroke affect tens of millions of individuals in the USA alone, and are becoming a more severe problem with the aging population. Although significant effort is being invested for identification of the molecular processes involved, existing chemical and physical therapies do not promise restoration of lost neuronal circuits beyond the short term remedy of symptoms. A potential solution could be the use of tissue transplantation to restore neuronal function. There have been human trials where transplantations, although variably, have resulted in functional recovery in Parkinson¿s (PD) and Huntington¿s (HD) diseases. Cell replacement for epilepsy and stroke has shown promise in several rodent studies, and the transplantation of retinal cells to treat degenerative eye diseases is under evaluation in several laboratories. Although there are still many unknowns, in various cases, it has been observed that functional improvements occurred owing to the integration of grafted neurons into existing neuronal networks, and was not simply due to trophic factors released by the transplanted cells. Several studies have also shown that the adult brain is remarkably capable of providing signaling cues that guide the growth of neuronal processes and induce formation of synapses with desired targets when correct cell types are present within the grafts. Xenograft studies with animals larger than rodents have shown that these cues can function over long distances. However, while tissue transplantation may have significant potential, there are many scientific unknowns and several fundamental challenges exist as outlined in this proposal. Handling complexity of these challenges is currently beyond the capabilities of the largest laboratories in the world, and will likely require deployment of systematic high-throughput approaches that will not only address fundamental biological questions and rapidly test various hypotheses without bias, but also provide results that are, if promising, translatable to clinical trials. Challenges: (1) Human fetal or iPS-derived cells are either too scarce or tumorogenic for clinical use, (2) Transplanted cells are too heterogeneous, (3) Preparation of transplanted cells in the correct and synchronized stages is currently impossible, (4) Physical site of transplantation significantly varies from experiment to experiment, (5) Existing in vivo transplantation assays are too slow for screening of multitudes of different hypotheses. Innovation & Methodology: Here, we propose a systematic, unbiased, in vivo, large-scale, and high throughput approach for overcoming these challenges to in vitro differentiation and in vivo testing of transplanted neuronal tissues. The proposed methodologies here are applicable to most transplantation paradigms. The key technologies and strategies we will develop include: (A) RNA-mediated nuclear reprogramming without genetic modification, (B) Reprogramming human cell lineages by systematic ultra-high-throughput screening of RNA transcription factor cocktails using a massively parallel technology, (C) High-throughput transplantation of human cells into rodents (with minimal rodent sacrifice) and in vivo analysis of neuronal survival and integration.

问题：神经元损伤、退行性疾病以及帕金森病和亨廷顿病、癫痫和中风等疾病仅在美国就影响着数千万人，并且随着人口老龄化而成为更加严重的问题。尽管正在投入大量精力来识别所涉及的分子过程，但现有的化学和物理疗法并不能保证除了短期治疗症状之外还能恢复丢失的神经元回路。一个潜在的解决方案可能是使用组织移植来恢复神经元功能。已经有一些人体试验表明，移植虽然效果各异，但已导致帕金森病 (PD) 和亨廷顿病 (HD) 的功能恢复。细胞替代治疗癫痫和中风已在多项啮齿类动物研究中显示出前景，多个实验室正在评估用于治疗退行性眼病的视网膜细胞移植。尽管仍有许多未知因素，但在各种情况下，已经观察到功能改善是由于移植神经元整合到现有神经元网络中而发生的，而不仅仅是由于移植细胞释放的营养因子所致。几项研究还表明，当移植物中存在正确的细胞类型时，成人大脑非常能够提供指导神经元过程生长的信号线索，并诱导具有所需目标的突触形成。对比啮齿动物更大的动物进行的异种移植研究表明，这些信号可以在长距离内发挥作用。然而，虽然组织移植可能具有巨大的潜力，但仍存在许多科学未知数，并且如本提案所述，存在一些基本挑战。处理这些挑战的复杂性目前超出了世界上最大的实验室的能力，并且可能需要部署系统的高通量方法，这些方法不仅可以解决基本的生物学问题并快速无偏见地测试各种假设，而且还可以提供可转化为临床试验的结果（如果有希望的话）。挑战：(1) 人类胎儿细胞或 iPS 衍生细胞对于临床使用来说要么太稀缺，要么具有致瘤性，(2) 移植细胞的异质性太强，(3) 目前不可能在正确且同步的阶段制备移植细胞，(4) 移植的物理部位因实验而异，(5) 现有的体内移植测定对于筛选大量细胞而言速度太慢 的不同假设。创新与方法：在这里，我们提出了一种系统的、公正的、体内的、大规模的、高通量的方法，用于克服移植神经组织体外分化和体内测试的这些挑战。这里提出的方法适用于大多数移植范例。我们将开发的关键技术和策略包括：（A）无需基因修饰的RNA介导的核重编程，（B）使用大规模并行技术通过系统性超高通量筛选RNA转录因子混合物来重编程人类细胞谱系，（C）将人类细胞高通量移植到啮齿动物中（以最小的啮齿动物牺牲）以及神经元存活和整合的体内分析。