Genetic control of postembryonic wound healing in Drosophila

描述（由申请人提供）：组织修复能力是多细胞生物的基本特性，通常对生存至关重要。尽管其生物学和临床重要性，启动和终止表皮伤口闭合的信号仍然不清楚，执行这一过程所需的基因也是如此。这部分是由于脊椎动物模型生物体中伤口修复反应的复杂性，以及组织修复尚未在更简单的模型遗传生物体中进行广泛研究的事实，在更简单的模型遗传生物体中，快速基因发现和基因功能的精确分析非常容易。本研究项目的重点是胚胎后伤口愈合的分子遗传控制。我们的指导假设是，有一个保守的分子遗传程序的细胞-细胞信号事件，启动，调节，执行，并终止修复过程。为了测试这一假设在一个遗传学上易于处理的模型系统，我们已经建立了表皮伤口愈合试验，果蝇幼虫，并证明伤口闭合需要果蝇Jun N-末端激酶（JNK）和其他八个基因，我们确定了在试点条件遗传筛选伤口闭合突变体。对于该试验性筛选，我们开发了转基因报告幼虫，其允许伤口闭合的实时可视化以及可以干扰或增强该过程的外源RNAi转基因的表皮特异性表达。我们的长期目标是使用我们独特的检测方法和工具来鉴定有效伤口闭合所需的基因互补，并确定这些基因在伤口闭合过程中的功能。我们的短期目标列举在以下具体目标：1。为了验证创伤诱导的JNK信号传导是由PDGF/VEGF受体PVR的果蝇同源物激活的假设，PVR是我们初步筛选中鉴定的一种受体酪氨酸激酶。2.为了验证JNK信号通路激活启动创伤反应细胞中的细胞迁移的假设。3.通过扩大我们的条件遗传筛选策略，鉴定和表征伤口闭合所需的新基因。该项目代表了第一个系统的研究胚胎后伤口闭合的模式遗传生物，并有很大的潜力，揭示难以捉摸的信号，控制伤口闭合。考虑到大多数基本过程所需的基因的保守性，我们预计该项目将告知我们对脊椎动物和病理生理状态（如癌症）中伤口闭合的理解，其中伤口愈合反应被认为是不适当的激活或调节。该研究项目采用了一种模式遗传生物果蝇，以揭示胚胎后伤口愈合的遗传控制，这是一个与人类健康直接相关的过程。伤口愈合对于创伤和手术的恢复至关重要，这两者都是常见的情况。考虑到大多数基本生物过程所需的基因的保守性，我们预计该项目将告知我们对脊椎动物和病理生理状态（如癌症和各种皮肤病）中伤口闭合的理解，其中伤口愈合反应被认为是不适当的激活或调节。

DESCRIPTION (provided by applicant): The capacity for tissue repair is a fundamental property of multicellular organisms that is often critical for survival. Despite its biological and clinical importance, the signals that initiate and terminate epidermal wound closure remain obscure, as do the genes required to execute this process. This is partly due to the complexity of wound repair responses in vertebrate model organisms and the fact that tissue repair has not been studied extensively in simpler model genetic organisms where rapid gene discovery and precise analysis of gene function are greatly facilitated. This research project focuses on the molecular genetic control of postembryonic wound healing. Our guiding hypothesis is that there is a conserved molecular genetic program of cell-cell signaling events that initiates, regulates, executes, and terminates the repair process. To test this hypothesis in a genetically tractable model system we have established epidermal wound healing assays using Drosophila larvae and demonstrated that wound closure requires the Drosophila Jun N-terminal kinase (JNK) and eight other genes we identified in a pilot conditional genetic screen for wound closure mutants. For this pilot screen we developed transgenic reporter larvae that allow live visualization of wound closure as well as epidermal-specific expression of exogenous RNAi transgenes that could interfere with or enhance this process. Our long term objective is to use our unique assays and tools to identify the complement of genes required for efficient wound closure and determine the function of these genes during wound closure. Our shorter term goals are enumerated in the following specific aims: 1. to test the hypothesis that wound- induced JNK signaling is activated by the Drosophila homolog of the PDGF/VEGF receptor, PVR, a receptor tyrosine kinase identified in our pilot screen. 2. To test the hypothesis that JNK signaling pathway activation initiates cell migration in wound-responsive cells. 3. To identify and characterize novel genes required for wound closure by expanding our conditional genetic screening strategy. This project represents the first systematic study of postembryonic wound closure in a model genetic organism and has great potential for uncovering the elusive signals that control wound closure. Given the conservation of genes required for most fundamental processes we expect that this project will inform our understanding of wound closure in vertebrates and in pathophysiological states, such as cancer, where the wound healing response is thought to be improperly activated or regulated. This research project employs a model genetic organism, the fruit fly, to uncover the genetic control of postembryonic wound healing, a process of immediate relevance to human health. Wound healing is critical for recovery from trauma and surgery, both of which are common occurrences. Given the conservation of genes required for most fundamental biological processes we expect that this project will inform our understanding of wound closure in vertebrates and in pathophysiological states, such as cancer and a variety of skin diseases, where the wound healing response is thought to be improperly activated or regulated.