Epithelial polarity during skin regeneration

描述（由申请人提供）：本提案的总体目标是了解正常上皮细胞增殖和组装成三维（3D）组织的分子过程以及该过程在癌症中如何出错。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)开发一种系统，利用该系统暂时诱导皮肤角质形成细胞中特异性siRNA的表达。(3)靶向关键极性分子，通过siRNA在体外原代角质形成细胞中敲低，并确定对上皮层细胞结构组织的影响，特别关注粘附连接、桥粒、肌动蛋白和基于微管的细胞骨架以及顶端和基底膜结构域的结构、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的平衡的影响。(4)将表达可诱导siRNA转基因的角质形成细胞移植到裸鼠背部皮肤上，并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.