Elucidating the role of Ftz-f1 as a mediator of steroid hormone-dependent activity in stem cells and their progeny

项目总结 细胞重新编程的最新进展引起了人们对干细胞使用的浓厚兴趣 用于再生治疗的细胞，以取代受损或丢失的细胞。干细胞整合了多种 维持其命运和增殖能力的内在和外在线索。重要的是，这些线索 包括类固醇激素，它在儿童生长发育、怀孕和 疾病和核激素受体，它们接收类固醇信号来调节生理 动态平衡。对干细胞如何应对人体生理变化的基本认识 因此，这是增加干细胞在临床治疗中使用的必要前提。喜欢 其他核激素受体信号通路，昆虫类固醇激素蜕皮激素已知 引发上下文相关的细胞反应；然而，这些反应是如何产生的在很大程度上是未知的 已实现。核激素受体FTZ-F1是蜕皮激素靶点，但它也是 其他蜕皮激素靶点(即E74和E75)在胚胎和胚胎中的最大转录反应 幼虫组织。这表明FTZ-F1的活性启动了一些细胞对蜕皮激素的反应，这种反应是通过上调- 调节特定的转录途径。尽管对突变等位基因的鉴定已近25年 到目前为止，还没有关于FTZ-F1在卵巢中的功能的研究。我们的研究将测试 中心假设FTZ-F1在卵巢中作为蜕皮激素信号的竞争因子。 果蝇卵巢中的生殖系干细胞(GSCs)非常适合这些研究， 容易接近的解剖位置，对类固醇激素的敏感性，以及 基因和实验技术。我们的研究不仅将揭示关于 FTZ-F1在干细胞和生殖中的作用，但也可以作为一种新的范例 体内环境依赖的类固醇激素信号转导研究。在我新的独立实验室里，我们将利用 果蝇遗传突变体和体内细胞特异性基因敲除研究是否和如何 FTZ-F1调节GSCs及其后代，并测试FTZ-F1是否启动特定细胞的蜕皮激素 发信号。在目标1中，我们将探讨FTZ-F1在神经干细胞分化和分化中的作用。 后代。在目标2中，我们将研究FTZ-F1是否控制GSCs的细胞周期及其 后代。在目标3中，我们将使用遗传互作实验来确定FTZ-F1 在功能上与蜕皮激素信号相互作用。鉴于果蝇和人类之间的相似性 类固醇激素信号，我们的研究将有助于阐明核激素受体如何区分 在体内调节上下文相关的转录途径以控制干细胞的功能。

PROJECT SUMMARY Recent advances in cell reprogramming have raised considerable interest in the use of stem cells for regenerative therapies to replace damaged or lost cells. Stem cells integrate a variety of intrinsic and extrinsic cues to maintain their fate and proliferative capacity. Importantly, these cues include steroid hormones, which fluctuate during childhood growth and development, pregnancy, and disease, and nuclear hormone receptors, which receive steroid signals to regulate physiological homeostasis. A basic understanding of how stem cells respond to changes in human physiology is therefore a necessary prerequisite to the increased use of stem cells in clinical therapy. Like other nuclear hormone receptor signaling pathways, the insect steroid hormone ecdysone is known to elicit context-dependent cellular responses; however, it is largely unknown how these responses are achieved. The nuclear hormone receptor Ftz-f1 is an ecdysone target, but it is also required for the maximal transcriptional response of other ecdysone targets (namely, E74 and E75) in embryonic and larval tissues. This suggests that Ftz-f1 activity primes some cells to respond to ecdysone by up- regulating a specific transcriptional pathway. Despite the identification of mutant alleles nearly 25 years ago, no studies to date have addressed the function of Ftz-f1 in the ovary. Our studies will test the central hypothesis that Ftz-f1 acts as a competence factor for ecdysone signaling in the ovary. Germline stem cells (GSCs) in the Drosophila melanogaster ovary are well-suited for these studies, due to their easily accessible anatomical location, sensitivity to steroid hormones, and the availability of genetic and experimental techniques. Our studies will not only reveal important new information about the function of ftz-f1 in stem cells and reproduction, but can also serve as a novel paradigm for the study of context-dependent steroid hormone signaling in vivo. In my new independent lab, we will utilize Drosophila genetic mutants and in vivo cell-specific gene knockdown to investigate whether and how ftz-f1 regulates GSCs and their progeny, and test whether ftz-f1 primes specific cells for ecdysone signaling. In Aim 1, we will examine the role of ftz-f1 in the differentiation of GSCs and their progeny. In Aim 2, we will investigate whether ftz-f1 controls the cell cycle in GSCs and their progeny. In Aim 3, we will use genetic interaction experiments to determine whether ftz-f1 functionally interacts with ecdysone signaling. Given the similarity between Drosophila and human steroid hormone signaling, our study will help elucidate how nuclear hormone receptors differentially regulate context-dependent transcriptional pathways in vivo to control stem cell function.