Local Role for Steroids in Regenerative Growth in Drosophila

类固醇在果蝇再生生长中的局部作用

• 批准号: 10373939
• 负责人: Douglas Emmons Terry
• 金额: $ 4.68万
• 依托单位: EMORY UNIVERSITY
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2023-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10373939
• 关键词: Adult; Alleles; Anabolism; Androgens; Animals; Apoptotic; Back; Binding; Biological Models; Biology; Cells; Characteristics; Complex; Crustacea; Data; Development; Drosophila genus; Drosophila melanogaster; Ecdysone; Ecdysterone; Epithelial; Estrogens; Gene Expression; Gene Proteins; Genes; Genetic Transcription; Goals; Growth; Homologous Gene; Hormones; Human; Immunofluorescence Immunologic; Impairment; In Situ Hybridization; Injury; Laboratories; Ligand Binding Domain; Ligands; Light; Link; Malignant Neoplasms; Malignant neoplasm of prostate; Measures; Methods; Modeling; Molecular; NCOA3 gene; Natural regeneration; Nuclear Hormone Receptors; Oncoproteins; Orthologous Gene; Output; Pathologic; Pathway interactions; Pattern; Peripheral; Physiologic pulse; Porifera; Production; Proliferating; Proteins; Publishing; RNA; RNA Interference; Receptor Activation; Receptor Signaling; Regenerative pathway; Regenerative research; Reporter; Role; Signal Pathway; Signal Transduction; Site; Skin wound healing; Stanolone; Stem Cell Development; Stem Cell Factor; Steroid Receptors; Steroids; Surgical wound; System; Temperature; Testing; Therapeutic; Tissues; Transcription Coactivator; Transgenes; Tumor Suppressor Genes; Wing; Work; blastema; clinically significant; coactivator-associated arginine methyltransferase 1; cofactor; disc regeneration; ecdysone receptor; epithelial stem cell; epithelial wound; epithelium regeneration; experimental study; fly; genetic manipulation; germline stem cells; hormonal signals; insight; limb regeneration; malignant breast neoplasm; nano; notch protein; programs; promoter; receptor binding; recruit; regenerative; regenerative growth; stem; steroid hormone; success; tissue regeneration; tissue repair; tumor; wound; wound healing

PROJECT SUMMARY The fruit fly, Drosophila melanogaster, is a well-established model system to define conserved mechanisms that control proliferation, survival, invasiveness, and stem-like qualities of developing epithelia. A number of clinically significant oncogenes and tumor suppressors have been discovered and defined in flies (e.g. Yki/Yap1, Notch and archipelago/Fbw7), and multiple Drosophila tumor models are currently being used as discovery platforms to identify potential therapeutic compounds and cocktails. The Drosophila Taiman (Tai) and Yorkie (Yki) transcriptional co-activator proteins are the sole fly orthologs of the well-established human oncoproteins SRC-3 and Yap1. Tai is the prime coactivator for the ecdysone receptor (EcR), a functional homolog of nuclear hormone receptors, that controls many aspects of epithelial and stem cell development. Yki is the main transcriptional effector of the Hippo pathway. Our laboratory discovered that Yki and Tai physically associate on target gene promoters and that this Tai-Yki complex enables crosstalk between the Hippo and steroid hormone pathways during developmental and pathologic growth in Drosophila. The current project is focused on a role for the Tai-Yki axis in homeostatic regrowth of wing epithelium following wounding, and thus lies at the intersection of wound healing and cancer noted by Harold Dvorak’s prescient description of cancer as “wounds that do not heal”. I have found preliminary evidence that transient and local reduction in the ability of cells surrounding epithelial wounds to synthesize 20-hydroxyecdysone (20HE), the steroid ligand of EcR, inhibits wound repair and regeneration. In parallel, I have found that EcR transcriptional activity is also significantly induced within cells surrounding the wound. These data, in light of the Tai-Yki complex, could link 20HE/EcR steroid signaling to Yki/Yap1-driven growth at the site of the wound. Indeed, Tai supports expression of certain Yki pro-growth targets in uninjured discs that are upregulated during regeneration (e.g. dIlp8). Thus, I will test the hypothesis that the steroid hormone 20HE is required for imaginal wing disc regeneration through promoting transcriptional activity of Tai-dependent Yki targets. The Specific Aims of this project are: 1) test the requirement for 20HE biosynthesis in wing disc regeneration; 2) define the pattern of EcR activity in regenerating wing discs; 3) test the local requirement for the Tai-Yki axis in regenerative growth. In Aim 1, I will compare the extent of regeneration of wing discs depleted of 20HE biosynthesis genes to control discs, and determine the pattern of 20HE biosynthesis gene expression in regenerating imaginal wing discs. In Aim 2, I will place EcR activation into the context with other pathways activated during regeneration. In Aim 3, I will determine the effect of disrupting Tai-Yki association on the extent of regeneration and Tai-dependent Yki target expression in wing discs. Success in these studies will provide insight into how local hormone synthesis regulates homeostatic wound repair and, potentially, pathologic cancer growth.

项目概要 果蝇（Drosophila melanogaster）是一个完善的模型系统，用于定义保守机制 控制发育中上皮细胞的增殖、存活、侵袭性和干状特性。一些 已在果蝇中发现并定义了具有临床意义的癌基因和肿瘤抑制基因（例如 Yki/Yap1、Notch 和 archipelago/Fbw7) 和多种果蝇肿瘤模型目前被用作 发现平台来识别潜在的治疗化合物和鸡尾酒。果蝇泰曼 (Tai) 和 Yorkie (Yki) 转录共激活蛋白是成熟的人类果蝇的唯一直系同源蛋白 癌蛋白 SRC-3 和 Yap1。 Tai 是蜕皮激素受体 (EcR) 的主要共激活剂，蜕皮激素受体是一种功能性 核激素受体的同源物，控制上皮细胞和干细胞发育的许多方面。 Yki 是 Hippo 通路的主要转录效应子。我们实验室发现Yki和Tai 与目标基因启动子物理关联，并且该 Tai-Yki 复合体能够实现 果蝇发育和病理生长过程中的河马和类固醇激素途径。 当前项目的重点是 Tai-Yki 轴在翼上皮稳态再生中的作用 受伤后发生，因此位于哈罗德·德沃夏克（Harold Dvorak）指出的伤口愈合和癌症的交叉点 有先见之明地将癌症描述为“无法愈合的伤口”。我发现初步证据表明瞬态 上皮伤口周围细胞合成 20-羟基蜕皮酮的能力局部降低 (20HE) 是 EcR 的类固醇配体，抑制伤口修复和再生。与此同时，我发现 EcR 伤口周围细胞内的转录活性也被显着诱导。这些数据，鉴于 Tai-Yki 复合物可以将 20HE/EcR 类固醇信号传导与伤口部位 Yki/Yap1 驱动的生长联系起来。 事实上，Tai 支持未受伤椎间盘中某些 Yki 促生长靶点的表达，这些靶点在 再生（例如 dIlp8）。因此，我将检验以下假设：类固醇激素 20HE 是 通过促进 Tai 依赖性 Yki 靶标的转录活性来实现成虫翼盘再生。这 该项目的具体目标是：1）测试翼盘再生中20HE生物合成的需求； 2） 定义再生翼盘中 EcR 活动的模式； 3) 测试Tai-Yki轴的本地要求 再生生长。在目标 1 中，我将比较耗尽 20HE 的翼盘的再生程度 控制椎间盘的生物合成基因，并确定 20HE 生物合成基因在椎间盘中的表达模式 再生想象的翼盘。在目标 2 中，我将把 EcR 激活与其他途径放在一起 再生期间被激活。在目标 3 中，我将确定破坏 Tai-Yki 协会对 翼盘再生程度和 Tai 依赖性 Yki 靶标表达。这些研究的成功将 深入了解局部激素合成如何调节稳态伤口修复，并有可能 病理性癌症生长。