Regulation of Cell-Cell Interactions by Matrix Metalloproteases

描述（由申请人提供）：信号分子、细胞外基质组分和分泌的蛋白酶之间的复杂相互作用调节组织结构、功能和稳态。这个建议是建立在最近建立的范例外基质金属蛋白酶（MMP）介导的机制的细胞信号的调节。果蝇Mmp 2切割硫酸肝素蛋白聚糖（HSPG）Dally，以将其从支持FGF-R信号传导的细胞表面结合共受体转化为可溶性FGF抑制剂。这种机制控制果蝇幼虫的分支形态发生，但也可能调节其他FGF依赖性过程，包括上皮-间充质相互作用、发育组织者的模式化和组织重塑。除了FGF之外，许多细胞外信号传导分子通过与HSPG（肝素结合生长因子、VEGF、HIV-TAT、Wnt、Hh、TGF-2）的相互作用来调节。可以想象，这些蛋白质的功能也可能受到本文提出的机制的影响。实验计划将使用申请方建立的细胞培养试验探索Mmp 2和Dally之间相互作用的机制基础。这些实验将提供深入了解细胞表面结合的基质金属蛋白酶的结构-功能关系，并可能产生一般信息的机制管理的MMPs的监管特异性。体内实验将探索MMPs，HSPGs和FGF之间的调节相互作用，并将测试Dally的蛋白水解片段可以作为细胞外信号传导，图案化和器官形成的特异性调节剂的假设。在最后一个目标中，在细胞培养和果蝇中的发现将被用于两种哺乳动物系统，以询问是否可以利用本文描述的基于蛋白水解的调节机制来逆转致癌FGF信号传导的作用。该提案的实验计划受益于果蝇中强大的遗传和成像工具。果蝇系统的另一个优点是MMP的遗传冗余大大减少（果蝇中有2个MMP基因，哺乳动物中有26个）。果蝇的实验优势得到了FGF依赖性肿瘤形成的哺乳动物模型所提供的癌症相关性的补充。 公共卫生相关性：基质金属蛋白酶（MMP）和FGF信号转导的失调与肿瘤-间质相互作用、转移形成和肿瘤血管生成有关。该项目将研究最近发现的MMP活性和FGF信号之间的功能联系，可能与恶性肿瘤有关。将测试由MMP产生的FGF信号传导的特异性抑制剂的潜在肿瘤抑制功能。

DESCRIPTION (provided by applicant): Complex interactions between signaling molecules, extracellular matrix components and secreted proteases regulate tissue structure, function and homeostasis. This proposal is founded on a recently established paradigm for the regulation of extra cellular signaling by matrix metalloprotease (MMP) - mediated mechanisms. Drosophila Mmp2 cleaves the heparin sulfate proteoglycan (HSPG) Dally, to convert it from a cell surface bound co receptor that supports FGF-R signaling to a soluble inhibitor of FGF. This mechanism controls branching morphogenesis in Drosophila larvae, but may also modulate other FGF- dependent processes, including epithelial-mesenchymal interactions, patterning by developmental organizers, and tissue remodeling. Many extracellular signaling molecules in addition to FGF are regulated by interactions with HSPGs, (Heparin binding growth factors, VEGF, HIV-TAT, Wnt, Hh, TGF-2). It is conceivable that the function of these proteins might also be influenced by the mechanism proposed here. The experimental plan will explore the mechanistic basis of the interaction between Mmp2 and Dally using cell culture assays established by the applicant. These experiments will provide insight into the structure-function relationships in cell surface bound matrix metalloproteases and may yield general information on the mechanisms governing the regulatory specificity of MMPs. In vivo experiments will explore the regulatory interplay between MMPs, HSPGs, and FGF and will test the hypothesis that proteolytic fragments of Dally can act as specific regulators of extracellular signaling, patterning and organ formation. In a final aim the findings made in cell culture and in fruit flies will be taken into two mammalian systems to ask whether the proteolysis- based regulatory mechanism characterized here might be exploited to reverse the effects of oncogenic FGF signaling. The experimental plan of the proposal benefits from the powerful genetic and imaging tools available in Drosophila. A further advantage of the fruit fly system is the much-reduced genetic redundancy of MMPs (2 mmp genes in Drosophila vs. 26 in mammals). The experimental advantages of Drosophila are complemented by the cancer relevance provided by the mammalian models of FGF-dependent tumor formation. PUBLIC HEALTH RELEVANCE: Deregulation of Matrix metalloproteases (MMPs) and FGF signaling has been implicated in tumor-stroma interactions, metastasis formation and tumor angiogenesis. This project will study a recently discovered functional connection between MMP activity and FGF signaling that might be relevant in malignancy. The potential tumor suppressive function of a specific inhibitor of FGF signaling, which is generated by MMP, will be tested.