Hearing loss in claudin 11-null mice

描述(申请人提供)：这个项目的长期目标是确定内耳血管纹紧密连接的功能，并确定克劳丁家族成员的多样性是否包括位于中阶周围的战斗连接具有重叠或非重叠特性。从这些研究中获得的知识将为深入了解血管纹在听力和钾循环到内淋巴中的作用提供深入的见解。其具体目的是：1)验证Claudin//空小鼠内耳病理起源于形态缺陷的假说。Claudin 11在E13.5和成年胚胎发育中的前庭耳蜗器中表达，并将寻找在发育过程中和出生后大体结构变化的证据，这可能解释基因敲除小鼠的病理。2)验证Claudin 11基因缺失小鼠出现早期听力障碍的假设。年轻的成年基因敲除小鼠表现出听力损失的听性脑干反应(ABR)阈值升高，进一步的ABR测试以及不同年龄的耳蜗内电位和DPOAEs的测量将揭示这种表型在小鼠正常开始听力开始时是进行性的还是存在的。3)优化外源基因在血管纹基底细胞中表达的转化盒。已有的基本细胞特异性增强子元件将位于Claudin 11基因内，并用于驱动β-半乳糖苷酶报告基因在耳蜗中的表达，Reporter的表达将被鉴定，以期在耳蜗中表达几个claudin cDNA，试图挽救Claudin 11基因缺失小鼠的听力损失。

DESCRIPTION (provided by applicant): The long term goals of this project are to define the functions of tight junctions in Stria vascularis of the inner ear and to determine if the diversity of Claudin family members that comprise fight junctions located around Scala media have overlapping or non-overlapping properties. The knowledge gained from these studies will provide deep insights into the roles of the stria vascularis in hearing and potassium recycling to the endolymph. The specific aims are: 1) to test the hypothesis that inner ear pathology in Claudin//-null mice stems from morphological defects. Claudin 11 is expressed in the developing vestibulocochlear apparatus of embryos from E13.5 as well as in adults and evidence of gross structural changes during development and postnatally that could account for the pathology in the knockout mice will be sought. 2) to test the hypothesis that Claudin 11-null mice exhibit early hearing defects. Young adult knockout mice exhibit elevated auditory brainstem response (ABR) thresholds which indicate hearing loss, Further testing of ABRs as well as measurements of endocochlear potentials and DPOAEs at different ages will reveal if this phenotype is progressive or present at the time mice normally start to hear. 3) to optimize a transgene cassette for the expression of heterologous genes in basal cells of Stria vascularis. Basal cell-specific enhancer elements already in-hand will be located within the Claudin 11 gene and used to drive expression of a beta-galactosidase reporter gene in the cochlea, Reporter expression will be characterized with a view to expressing several claudin cDNAs in the cochlea in attempts to rescue hearing loss in Claudin 11-null mice.