Notch signaling and fkh cooperate to maintain intestinal stem cells in Drosophila

Notch信号和fkh合作维持果蝇肠道干细胞

• 批准号: 9024520
• 负责人: Huaqi Jiang
• 金额: $ 36.39万
• 依托单位: UT SOUTHWESTERN MEDICAL CENTER
• 依托单位国家: 美国
• 财政年份: 2015
• 资助国家: 美国
• 起止时间: 2015-03-01 至 2020-02-29
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/9024520
• 关键词: Address; Adult; Binding; Binding Sites; Cell physiology; Cells; ChIP-seq; Collaborations; Development; Drosophila genus; E protein; Embryonic Development; Feedback; Gene Expression; Gene Targeting; Genes; Genetic Transcription; Genetic study; Genomic Segment; Genomics; Goals; Health; Homeostasis; Intestines; Mediating; Methods; Midgut; Modeling; Molecular Genetics; Natural regeneration; Pathway interactions; Pluripotent Stem Cells; RNA interference screen; Regulation; Reporting; Role; Signal Pathway; Signal Transduction; Somatic Cell; Specific qualifier value; Stem cells; System; Testing; Tissues; To specify; Undifferentiated; adult stem cell; base; embryonic stem cell; fly; gastrointestinal system; genetic approach; genome-wide; improved; notch protein; novel; progenitor; research study; response; stem; stem cell division; stem cell fate; transcription factor

 DESCRIPTION (provided by applicant): Recent reports have identified a transcriptional network that specifies the embryonic stem cell fate, which facilitated the breakthrough development of reprogramming somatic cells into pluripotent stem cells. Furthermore, increasing evidences suggest that the identities of mature cells are also defined by transcriptional networks. However, the transcriptional networks that specify adult stem cell fates are largely uncharacterized, mainly because the transcription factors regulating somatic stem cell fates are unknown. In this study, we hypothesize that a transcriptional network specifies the intestinal stem cell (ISC) fate in Drosophila adult midgut (intestine). We propose to identify thes critical ISC transcriptional regulators to establish a comprehensive stem cell transcriptional network that governs the fly ISC fate. In our preliminary studies, taking advantage of a robust fly gut regeneration model, we performed an RNAi screen to identify transcription factors required for midgut regeneration. We have characterized several transcription factor hits, including da (E-protein), fkh (FoxA), klu and dSox9. Specifically, we showed that loss of these transcriptional factors in the midgut progenitors leads to their ectopic differentiation in the midgut. Furthermore our genetic and molecular studies indicate that fkh and da collaborate to induce downstream genes including dSox9 and klu to specify the ISC fate. Based on that, we hypothesize that these transcription factors likely function as an ISC transcriptional network, which we aim to elaborate in this study. First, we propose to determine how two critical ISC transcription factors Fkh and Da collaborate to maintain ISCs by identifying their downstream transcription factor targets. Second, we propose to establish an ISC transcriptional network that specifies the fly ISC cell fate. Third, we propose to explore the mechanism how niche signals regulate the ISC transcriptional network to promote the differentiation of midgut progenitors. The establishment of a comprehensive intestinal stem cell transcriptional network will facilitate the accurate identification of its downstream stem cell genes to allow for the unprecedented functional analysis in order to uncover potential novel stem cell functions.

 描述（由申请人提供）：最近的报道已经鉴定了指定胚胎干细胞命运的转录网络，其促进了将体细胞重编程为多能干细胞的突破性发展。此外，越来越多的证据表明，成熟细胞的身份也由转录网络定义。然而，指定成体干细胞命运的转录网络在很大程度上是未知的，主要是因为调控体干细胞命运的转录因子是未知的。在这项研究中，我们假设转录网络指定的果蝇成年中肠（肠）的肠干细胞（ISC）的命运。我们建议确定关键的ISC转录调控因子，以建立一个全面的干细胞转录网络，管理苍蝇ISC的命运。在我们的初步研究中，利用一种强壮的苍蝇 在肠再生模型中，我们进行了RNAi筛选以鉴定中肠再生所需的转录因子。我们已经表征了几种转录因子命中，包括da（E-蛋白）、fkh（FoxA）、klu和dSox 9。具体来说，我们发现，这些转录因子在中肠祖细胞的损失导致他们的异位分化中肠。此外，我们的遗传和分子研究表明，fkh和da协作诱导下游基因，包括dSox 9和klu，以指定ISC的命运。基于此，我们假设这些转录因子可能作为ISC转录网络发挥作用，我们的目标是在这项研究中详细阐述。首先，我们建议确定两个关键的ISC转录因子Fkh和Da如何合作，以维持ISC通过确定其下游转录因子的目标。其次，我们建议建立一个ISC转录网络，指定苍蝇ISC细胞的命运。第三，探讨小生境信号调控ISC转录网络促进中肠祖细胞分化的机制。建立全面的肠道干细胞转录网络将有助于准确识别其下游干细胞基因，从而进行前所未有的功能分析，以发现潜在的新型干细胞功能。