Desmocollin 3 in the development and maintenance tissues

描述(由申请人提供)： 桥粒是连接上皮细胞的细胞连接。这些连接的缺陷会导致皮肤、附属物和心脏的后天和遗传性疾病。细胞培养实验证明，桥粒的跨膜成分桥粒(Desmocolin，DSC)对细胞黏附和桥粒与上皮细胞中间丝细胞骨架的连接至关重要。这个应用程序的重点是dsc3，我们已经证明了它是小鼠正常胚胎发育所必需的。 体外实验表明，dsc3在外胚层来源的组织和器官的发育和分化中发挥着重要作用，很可能是通过提供来自相同分化途径的细胞之间的选择性黏附。此外，越来越多的证据表明，dsc3可能在某些癌症中发挥肿瘤抑制作用。为了明确dsc3在体内的作用，我们提出了以下具体目标：1.通过分析我们已建立的dsc3基因敲除小鼠，阐明dsc3在早期胚胎发育中的作用。2.通过阻断条件性dsc3基因缺失小鼠胚胎和出生后不同时间点的dsc3表达，以确定dsc3在皮肤发育和维持中的作用。我们将采用基于Cre/loxP的基因敲除系统，允许全身性和局灶性基因消融。3.通过对dsc3缺失角质形成细胞的分析，研究dsc3消融对体外桥粒组装和功能的影响。4.通过在肿瘤从良性乳头状瘤向浸润性癌转化的不同阶段灭活dsc3基因，确定dsc3基因消融是否通过灭活dsc3基因来促进皮肤癌变小鼠的肿瘤进展。

DESCRIPTION (provided by applicant): Desmosomes are cell junctions that connect epithelial cells. Defects in these junctions cause acquired and inherited diseases of the skin, its appendages and the heart. Cell culture experiments provided evidence that desmocollins (dsc), which are transmembrane components of desmosomes, are crucial for cell adhesion and the connection of desmosomes to the intermediate filament cytoskeleton of epithelial cells. This application focuses on dsc3, which we have shown to be required for normal embryonic development in the mouse. In vitro experiments suggest that dsc3 plays an important role in the development and differentiation of ectoderm-derived tissues and organs, most likely by providing selective adhesion between cells from the same differentiation pathway. Furthermore, evidence is accumulating that dsc3 might function as tumor suppressor in certain carcinomas. To define the role of dsc3 in vivo, we propose the following specific aims: 1. To elucidate the role of dsc3 in early embryonic development by analyzing dsc3 knockout mice that we have generated. 2. To determine the contributions of dsc3 to development and maintenance of the skin by ablating dsc3 expression in conditional dsc3 null mice at different time points during embryonic and postnatal development. We will employ a Cre/LoxP-based gene knockout system that allows systemic and focal gene ablation. 3. To characterize the effects of dsc3 ablation on desmosome assembly and function in-vitro by analyzing dsc3 null keratinocytes. 4. To determine whether dsc3 gene ablation facilitates tumor progression in mice subjected to a skin carcinogenesis protocol by inactivating the dsc3 gene at different stages of tumor conversion from benign papillomas to invasive carcinomas.