Epithelial polarity during skin regeneration

描述(申请人提供)：这项提案的全球目标是了解正常上皮细胞极化并组装成三维(3D)组织的分子过程，以及这一过程在癌症中是如何出错的。以哺乳动物表皮为模型，我的目标是(1)确定哪些极性基因同源物在小鼠表皮中表达。(2)建立在皮肤角质形成细胞中暂时诱导特异性siRNAs表达的系统。(3)在原代角质形成细胞中靶向siRNA击倒的关键极性分子，并确定对上皮细胞结构的影响，特别是黏附连接、桥粒、肌动蛋白和基于微管的细胞骨架以及顶端和基底膜区域的结构、组成和动力学。我还将确定极性丧失对角质形成细胞增殖和分化之间平衡的影响。(4)将表达诱导性siRNA转基因的角质形成细胞移植到裸鼠背部皮肤上，以确定受损的极性如何影响体内表皮的增殖、形态发生和迁移。

DESCRIPTION (provided by applicant): The global objective of this proposal is to understand the molecular process by which normal epithelial cells polarize and assemble into a three dimensional (3D) tissue and how this process goes awry in cancers. Using the mammalian epidermis as a model, I aim to (1) determine which polarity gene homologues are expressed in mouse epidermis. (2) Develop a system with which to temporally induce the expression of siRNAs specifically in skin keratinocytes. (3) Target key polarity molecules for knock down by siRNA in primary keratinocytes in vitro and determine the consequences to the organization of cellular architecture in epithelial sheets with particular focus on the structure, composition and dynamics of adherens junctions, desmosomes, actin and microtubule-based cytoskeletons and apical and basal membrane domains. I will also determine the effects of loss of polarity on the balance between keratinocyte proliferation and differentiation. (4) Graft keratinocytes expressing inducible siRNA transgenes on the back skin of a nude mouse and determine how impaired polarity affects proliferation, morphogenesis and migration in the epidermis in vivo.