Basement Membrane Homeostasis and Repair

项目摘要 基底膜是细胞外基质的普遍存在和保守的片层， 分离组织类型和隔室。基底膜的厚度和刚度 不同的组织中，尽管它们都有一套共同的核心成分， 这些差异的起源和维持尚不清楚。尽管有大量的生物化学 由于它们在体外组装的知识，它们通常被认为是静态的， 形成，所以很少有人知道如何基膜保持健康或 损坏后如何修复。我实验室的最新数据表明， 成人组织中的基底膜是惊人的动态的，需要持续的交联 和蛋白水解，即使在没有外部损伤的情况下也能发挥其正常功能。 这项提案将研究基底膜稳态的机制， 修复.首先，我们将测量它们在未受损组织中的组装和分解率， 然后确定交联和蛋白水解如何影响这些速率。第二，我们将确定 稳态与修复过程的相似性和不同之处，调查营业额 率和来源的基膜成分;我们将筛选，以确定新的基因 重要的是基底膜的维护和修复。最后，我们将测试一个令人兴奋的， 一种新的模型，可以解释一些基底膜如何具有不同的性质， 另一些是以胶原蛋白伴侣蛋白酶活性为中心的模型。所有这些目标将 利用果蝇，它有一个紧凑的基因组和优秀的遗传工具。的 这项研究的发现对细胞生物学、组织修复 特别是，它们将与基底膜疾病和 肿瘤转移，因为基底膜是癌细胞迁移的重要障碍， 了解它们的动力学将有助于建立肿瘤转移的模型。

Project Summary Basement membranes are ubiquitous and conserved sheets of extracellular matrix that separate tissue types and compartments. The thickness and stiffness of basement membranes varies in different tissues, even though they all share a common set of core components, and the origin and maintenance of these differences is not understood. Despite extensive biochemical knowledge of their in vitro assembly, they are often considered to be static after they have formed, and so very little is known about how basement membranes are maintained in health or how they are repaired after damage. Recent data from my laboratory indicates that assembled basement membranes in adult tissues are surprisingly dynamic, requiring continuing crosslinking and proteolysis for their proper function even in the absence of external damage. This proposal will investigate mechanisms of basement membrane homeostasis and repair. First, we will measure their assembly and disassembly rates in undamaged tissue, and then determine how crosslinking and proteolysis affect those rates. Second, we will determine how homeostasis is similar to and different from the process of repair, investigating turnover rates and sources of basement membrane components; and we will screen to identify new genes important to basement-membrane maintenance and repair. Finally, we will test an exciting and novel model that may explain how some basement membranes have different properties than others, a model centered on the activity of the collagen chaperone SPARC. All these aims will utilize Drosophila melanogaster, which has a compact genome and excellent genetic tools. The discoveries emerging from this study will be important to cell biology generally, to tissue repair specifically, and they will have clinical relevance to diseases of basement membrane and to tumor metastasis, as basement membranes are important obstacles to cancer cell migration, and understanding their dynamics will shape models of tumor metastasis.