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。尽管它具有生物学和临床意义，但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式生物的伤口修复反应的复杂性，以及组织修复尚未在更简单的模式遗传生物中广泛研究，而更简单的模式遗传生物极大地促进了基因的快速发现和基因功能的精确分析。本项目主要研究胚胎后创面愈合的分子遗传调控。我们的指导假设是，存在一个保守的细胞-细胞信号事件的分子遗传程序，该程序启动、调节、执行和终止修复过程。为了在遗传可处理的模型系统中验证这一假设，我们使用果蝇幼虫建立了表皮伤口愈合试验，并证明伤口愈合需要果蝇Jun n -末端激酶（JNK）和我们在创伤愈合突变体的中试条件遗传筛选中发现的其他8个基因。为了这个试点筛选，我们开发了转基因报告幼虫，可以实时可视化伤口愈合，以及外源RNAi转基因的表皮特异性表达，可以干扰或增强这一过程。我们的长期目标是利用我们独特的检测方法和工具来鉴定有效伤口愈合所需的基因补体，并确定这些基因在伤口愈合过程中的功能。我们的短期目标列举在以下具体目标中：为了验证伤口诱导的JNK信号是由PDGF/VEGF受体的果蝇同源物PVR激活的假设，PVR是我们在试点筛选中发现的一种受体酪氨酸激酶。2. 验证JNK信号通路激活引发损伤反应细胞迁移的假说。3. 通过扩大我们的条件遗传筛选策略，鉴定和表征伤口愈合所需的新基因。该项目代表了胚胎后伤口愈合的第一个系统研究模式遗传生物，并有很大的潜力揭示控制伤口愈合的难以捉摸的信号。考虑到大多数基本过程所需的基因保护，我们期望该项目将告知我们对脊椎动物伤口愈合和病理生理状态（如癌症）的理解，在这些状态下，伤口愈合反应被认为是不正确激活或调节的。该研究项目采用了一种模式遗传生物——果蝇，来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。伤口愈合是创伤和手术后恢复的关键，这两种情况都很常见。鉴于大多数基本生物过程所需的基因保护，我们期望该项目将告知我们对脊椎动物和病理生理状态（如癌症和各种皮肤疾病）伤口愈合反应被认为是不正确激活或调节的伤口愈合反应的理解。

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.