Takahashi K, Coulombe P A
Department of Biological Chemistry, Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
Proc Natl Acad Sci U S A. 1996 Dec 10;93(25):14776-81. doi: 10.1073/pnas.93.25.14776.
One of the current limitations of gene transfer protocols involving mammalian genomes is the lack of spatial and temporal control over the desired gene manipulation. Starting from a human keratin gene showing a complex regulation as a template, we identified regulatory sequences that confer inducible gene expression in a subpopulation of keratinocytes in stratified epithelia of adult transgenic mice. We used this cassette to produce transgenic mice with an inducible skin blistering phenotype mimicking a form of epidermolytic hyperkeratosis, a keratin gene disorder. Upon induction by topical application of a phorbol ester, the mutant keratin transgene product accumulates in the differentiating layers of epidermis, leading to keratinocyte lysis after application of mechanical trauma. This mouse model will allow for a better understanding of the complex relationship between keratin mutation, keratinocyte cytoarchitecture, and hypersensitivity to trauma. The development of an inducible expression vector showing an exquisite cellular specificity has important implications for manipulating genes in a spatially and temporally controlled fashion in transgenic mice, and for the design of gene therapy strategies using skin as a tissue source for the controlled delivery of foreign substances.
当前涉及哺乳动物基因组的基因转移方案的局限性之一是缺乏对所需基因操作的空间和时间控制。以一个显示复杂调控的人类角蛋白基因为模板，我们鉴定出了在成年转基因小鼠分层上皮的角质形成细胞亚群中赋予可诱导基因表达的调控序列。我们使用这个盒式结构来培育具有可诱导皮肤水疱表型的转基因小鼠，该表型模拟了一种角蛋白基因紊乱——表皮松解性角化过度症。通过局部应用佛波酯诱导后，突变的角蛋白转基因产物在表皮的分化层中积累，导致在施加机械创伤后角质形成细胞裂解。这个小鼠模型将有助于更好地理解角蛋白突变、角质形成细胞细胞结构与创伤超敏反应之间的复杂关系。开发一种具有精确细胞特异性的可诱导表达载体，对于在转基因小鼠中以空间和时间可控的方式操纵基因，以及对于设计将皮肤作为外源物质可控递送的组织来源的基因治疗策略具有重要意义。
