Molecular mechanisms of nuclear reprogramming

描述(由申请人提供)： 描述(申请人提供)：造血干细胞移植(HSCT)使血液疾病的治疗发生了革命性的变化，但受到供者/接受者免疫不相容问题的严重限制。干细胞生物学的进步暗示了通过体细胞核重新编程产生基因匹配的组织来绕过这些限制的方法。然而，首先必须克服重大的技术和道德障碍。描述了一个为期5年的职业发展计划，在该计划中，首席研究员寻求增进对核重新编程的理解，同时在HSCT建立学术生涯。候选人将在分子遗传学和临床血液学/肿瘤学培训的基础上，在乔治·Q·戴利博士的指导下发展对发育和干细胞生物学的掌握。戴利博士是干细胞生物学领域的领军人物，他拥有一套独特的综合性研究计划来支持这一提议。鉴于波士顿儿童医院血液科在丰富和协作的研究环境中培训内科科学家的杰出记录，该计划是理想的。这项研究是由一个中心假设指导的，即对正常哺乳动物胚胎发育的仔细分析将揭示有助于体外重新编程的因素。这些研究集中在重新编程中两个鲜为人知的事件：DMA去甲基化和多能性的建立。利用分子、遗传和发育分析相结合的方法，我们的目标是确定与正常胚胎发生和重编程有关的候选因素的作用。其具体目的是：1)确定胞苷脱氨酶是否是受精卵中活跃的DMA去甲基化所必需的，以及它们是否促进核移植过程中的重编程，以及(2)确定转录因子Nanog是否在胚胎发生期间激活多潜能基因表达程序，以及它是否可以促进核移植后的重编程。这些目标解决了发育生物学中基本相关的问题，对干细胞治疗具有潜在的意义。此外，AIMS的实施将使首席研究人员能够发展必要的专业知识，以建立专门的科学生态位，并在此基础上建立HSCT的学术生涯。(摘要结束)

DESCRIPTION (provided by applicant): DESCRIPTION (provided by applicant): Hematopoietic stem cell transplantation (HSCT) has revolutionized the treatment of blood disorders, yet is severely limited by issues of donor/recipient immune incompatibility. Advances in stem cell biology hint at the means of circumventing these limitations through the generation of genetically matched tissues via somatic cell nuclear reprogramming. However, significant technical and ethical impediments must first be overcome. A 5-year career development plan is described wherein the principal investigator seeks to advance the understanding of nuclear reprogramming, while establishing an academic career in HSCT. The candidate will build on training in molecular genetics and clinical hematology/oncology to develop a command of developmental and stem cell biology under the mentorship of Dr. George Q. Daley. Dr. Daley is a leader in stem cell biology, with a comprehensive research program uniquely equipped to support the proposal. The plan is ideally conducted in the Division of Hematology at Children's Hospital, Boston, given the Division's distinguished record for training physician-scientists in a rich and collaborative research environment. The research is guided by the central hypothesis that careful analysis of normal mammalian embryonic development will reveal factors that can facilitate reprogramming in vitro. The studies focus on two poorly understood events in reprogramming: DMA demethylation and the establishment of pluripotency. Using a combination of molecular, genetic and developmental analyses, we aim to determine the roles of candidate factors implicated in normal embryogenesis and reprogramming. The specific aims are to: 1) Determine if cytidine deaminases are essential for active DMA demethylation in the zygote, and whether they facilitate reprogramming during nuclear transfer, and (2) Determine if the transcription factor Nanog activates a pluripotency gene expression program during embryogenesis, and whether it can facilitate reprogramming after nuclear transfer. The aims address questions of fundamental relevance in developmental biology, with potential significance for stem cell therapy. Additionally, execution of the aims will enable the principal investigator to develop the expertise necessary to establish a specialized scientific niche, from which an academic career in HSCT can be built. (End of Abstract)