Developmental reprogramming and transorganogenesis

发育重编程和跨器官发生

• 批准号: 8888152
• 负责人: Joel H. Rothman
• 金额: $ 31.05万
• 依托单位: UNIVERSITY OF CALIFORNIA SANTA BARBARA
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-04-01 至 2020-01-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/8888152
• 关键词: Adopted; Adult; Caenorhabditis elegans; Cancerous; Cell Signaling Process; Cell division; Cell fusion; Cells; Cellular Structures; Characteristics; Congenital Abnormality; DNA Binding Domain; Development; Dissection; EGF gene; Elements; Embryo; Embryonic Development; Endoderm; Event; Feedback; Fibroblasts; Gastrointestinal tract structure; Gene Expression; Gene Expression Profile; Genes; Germ Layers; Goals; Gonadal structure; Hand; Human; Intestines; Lead; Maintenance; Malignant Neoplasms; Metaplasia; Methods; Mitotic; Modeling; Molecular; Molecular Analysis; Molecular Genetics; Morphology; Organ; Pathway interactions; Patients; Pattern; Pharyngeal structure; Predisposition; Process; Property; Protein Dynamics; RNA Interference; Refractory; Regenerative Medicine; Regulator Genes; Research; Role; Series; Signal Transduction; Specificity; Staging; Structure; System; Tertiary Protein Structure; Testing; Tissues; Transplantation; Uterus; Vas deferens structure; Zebrafish; base; cell type; developmental genetics; developmental plasticity; functional genomics; gene repression; genetic selection; in vivo; induced pluripotent stem cell; insight; intercellular communication; male; malformation; member; notch protein; prevent; progenitor; protein degradation; public health relevance; screening; transcription factor; transdifferentiation

 DESCRIPTION (provided by applicant): The major objectives of the proposed research are to illuminate the cellular and molecular mechanisms that control plasticity of developing and differentiated cells in vivo and to investigate how post-mitotic differentiated cells can be transdifferentiated and remodeled into new cell types. The well-elucidated pathway for endoderm development in C. elegans will be applied to the molecular dissection of transdifferentiation and "transorganogenesis" (conversion of one organ into another). One component in this pathway, the ELT-7 GATA-type transcription factor, is capable of overriding the embryonic multipotency commitment transition ("MCT"), which normally locks cells into their differentiated states and prevents them from being reprogrammed. ELT-7 can cause differentiated pharynx cells in adults to be remodeled into cells with ultrastructural characteristics, and gene expression patterns, of intestinal cells, without intercession of a dedifferentiated intermediate or cell division. ELT-7 can also convert the developing uterus and vas deferens into "mini-guts," which show typical fine-structure gut morphology and that can be physically isolated. With these preliminary findings in hand, we will probe the mechanisms of transdifferentiation through three Specific Aims. In Aim 1, we will evaluate the specificity of targeting ELT-7 to the uterus and will test the hypothesis that uterus gut transorganogenesis involves superimposition of gonadal gene repression and recapitulation of normal gut development through analysis of transdifferentiated organs and transcriptional profiling of isolated "mini-guts." We will investigate the mechanisms of cellular remodeling during transdifferentiation, including the requirement for protein degradation, and will test the hypothesis that a discrete domain of ELT-7 allows for its ability to promote transdifferentiation. In Aim 2, we will investigate the role of cell-autonomous regulators, including PHA-4/FoxA, genes in the endoderm cascade, and iPS-promoting genes, as well cell-cell signaling processes, including Notch, EGF/ras and cell fusion, in modulating susceptibility to transdifferentiation. In Aim 3, we will undertake a comprehensive analysis of molecular components that regulate reprogramming by classical and functional genomics (RNAi-based) screens and direct genetic selections and, with our collaborators, will test the generality of the C. elegans transdifferentiation mechanisms in the zebrafish vertebrate model and in reprogramming of human fibroblasts to iPS cells. These studies may advance our understanding of the mechanisms involved in pre-cancerous metaplasias of the digestive tract. They could also lead to methods for generating patient-specific replacement organs and other strategies that advance regenerative medicine, and will provide insights into the mechanisms of organ malformation in birth defects.

 描述(申请人提供)：建议研究的主要目标是阐明体内发育和分化细胞可塑性的细胞和分子机制，并研究有丝分裂后分化的细胞如何转分化和重塑为新的细胞类型。线虫内胚层发育的已阐明途径将被应用于转分化和“转器官发生”(将一个器官转化为另一个器官)的分子解剖。该途径的一个组成部分，ELT-7 GATA型转录因子，能够覆盖胚胎多能性承诺转变(MCT)，后者通常将细胞锁定在它们的分化状态，并防止它们被重新编程。ELT-7可以使成人分化的咽部细胞重塑为具有肠道细胞超微结构特征和基因表达模式的细胞，而不需要去分化中间体或细胞分裂的中介。ELT-7还可以将发育中的子宫和输精管转化为“迷你肠道”，这种肠道表现出典型的精细结构的肠道形态，并且可以物理分离。有了这些初步的发现，我们将从三个特定的目的来探索转分化的机制。在目标1中，我们将评估将ELT-7靶向子宫的特异性，并将通过对跨分化器官的分析和分离的“迷你肠道”的转录图谱来检验子宫肠道跨器官发生涉及性腺基因抑制的叠加和正常肠道发育的重现的假设。我们将研究转分化过程中细胞重塑的机制，包括蛋白质降解的要求，并将检验ELT-7的离散结构域允许其促进转分化的假设。在目标2中，我们将研究细胞自主调节因子，包括PHA-4/FoxA，内胚层级联基因，iPS促进基因，以及细胞-细胞信号转导过程，包括Notch，EGF/ras和细胞融合，在调节转分化易感性中的作用。在目标3中，我们将通过经典和功能基因组学(RNAi)筛选和直接遗传选择，对调节重新编程的分子成分进行全面分析，并将与我们的合作者一起，在斑马鱼脊椎动物模型中测试线虫转分化机制的普遍性，以及在将人成纤维细胞重新编程为iPS细胞的过程中。这些研究可能会促进我们对消化道癌前化生的机制的理解。它们还可能导致产生特定于患者的替代器官的方法，以及其他促进再生医学的策略，并将为了解出生缺陷中器官畸形的机制提供见解。