Molecular mechanisms of nuclear reprogramming

描述（由申请人提供）： 描述（由申请人提供）：造血干细胞移植（HSCT）已经彻底改变了血液疾病的治疗，但受到供体/受体免疫不相容性问题的严重限制。干细胞生物学的进展暗示了通过体细胞核重编程产生基因匹配的组织来规避这些限制的方法。然而，必须首先克服重大的技术和道德障碍。描述了一个5年的职业发展计划，其中主要研究者旨在促进对核重编程的理解，同时建立HSCT的学术生涯。候选人将在乔治Q博士的指导下，在分子遗传学和临床血液学/肿瘤学方面的培训基础上，发展发育和干细胞生物学方面的知识。戴利戴利博士是干细胞生物学的领导者，拥有一个全面的研究计划，以支持这一提议。该计划最好在波士顿儿童医院血液科进行，因为该科在丰富的合作研究环境中培养医生科学家方面有着杰出的记录。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可以促进体外重编程的因素。这些研究集中在重编程中两个知之甚少的事件：DMA去甲基化和多能性的建立。使用分子，遗传和发育分析的组合，我们的目标是确定候选因素的作用，涉及正常胚胎发生和重编程。具体目标是：1）确定胞苷脱氨酶是否是合子中活跃的DMA去甲基化所必需的，以及它们是否促进核转移期间的重编程，以及（2）确定转录因子Nanog是否在胚胎发生期间激活多能性基因表达程序，以及它是否可以促进核转移后的重编程。这些目标解决了发育生物学中的基本相关问题，对干细胞治疗具有潜在意义。此外，目标的执行将使主要研究者能够发展必要的专业知识，以建立一个专门的科学利基，从HSCT的学术生涯可以建立。(End摘要）

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)