COBRE: UNE MED CTR: P3: ROLE OF MITF IN DEVELOPMENT OF THE RPE AND INNER EAR

这个子项目是许多研究子项目中利用 资源由NIH/NCRR资助的中心拨款提供。子项目和 调查员(PI)可能从NIH的另一个来源获得了主要资金， 并因此可以在其他清晰的条目中表示。列出的机构是 该中心不一定是调查人员的机构。 按照最初的提议，该项目涉及使用分子遗传学方法机械地关注导致产前酒精暴露(胎儿酒精综合症)后内耳畸形的发育事件的变化。流行病学证据表明，大约30%的受Fas影响的儿童经历了感音神经性听力损失，但其潜在机制在很大程度上尚不清楚。推测宫内酒精暴露引起的内耳/耳蜗畸形是由于酒精和视黄醇竞争酒精脱氢酶途径导致内源性维甲酸生物合成减少所致。这一假设通过使用具有Rare-LacZ结构的F9细胞的体外实验得到证实，在该实验中，随着培养液中乙醇浓度的增加，β-半乳糖苷酶染色(视黄酸反应元件(RARE)激活阳性)减少。给近交系SWV小鼠的妊娠母鼠注射乙醇会导致后代出现多种出生缺陷，包括脑外畸形、面中部发育不良、唇腭裂、心脏缺陷和尾部退化，所有这些都可以在喂食富含维生素A的饲料时得到预防。在小鼠和鸡胚胎模型中，研究了乙醇暴露对内耳形态的影响。然而，母亲酒精暴露的致畸效应被认为是多效性的，该项目重新关注涉及神经感觉系统的单个基因/途径。这项新计划将研究小眼炎相关转录因子(MITF)在视网膜色素上皮(RPE)和内耳血管纹发育中调节的遗传/生化途径。这将包括Mift在决定RPE和纹状体细胞命运中的功能，它对内皮生长因子的反应，以及它在调节氧化应激中的作用。

This subproject is one of many research subprojects utilizing the resources provided by a Center grant funded by NIH/NCRR. The subproject and investigator (PI) may have received primary funding from another NIH source, and thus could be represented in other CRISP entries. The institution listed is for the Center, which is not necessarily the institution for the investigator. The project, as initially proposed, involves using a molecular genetic approach to focus mechanistically on alterations in developmental events leading to malformations of the inner ear subsequent to prenatal alcohol exposure (Fetal Alcohol Syndrome; FAS). Epidemiological evidence suggests that approximately 30% of children affected with FAS experience sensorineural hearing loss, yet the underlying mechanisms are largely unknown. It was hypothesized that malformations of the inner ear/cochlea following in utero alcohol exposure resulted from a decrease in endogenous retinoic acid biosynthesis due to competition between alcohol and retinol for alcohol dehydrogenase enzyme pathways. This hypothesis was substantiated by in vitro experiments using an F9 cell line with a RARE-lacZ construct, in which a decrease in ?-galactosidase staining (positive for activation of the retinoic acid response element (RARE)) was demonstrated as increasing concentrations of ethanol were added to the media. Ethanol administration to pregnant dams of the inbred SWV murine strain resulted in offspring with multiple birth defects, including exencephaly, midfacial hypoplasia, cleft lip/palate, heart defects, and caudal regression, all of which were prevented when the mice were fed a diet rich in vitamin A. The impact of ethanol exposure on inner ear morphology was examined in both murine and chick embryo models. However, the teratogenic effects of maternal alcohol exposure were recognized to be very pleiotropic, and the project has re-focused on a single gene/pathway involved in a neurosensory system. The new proposal will investigate genetic/biochemical pathways regulated by microphthalmia-associated transcription factor (Mitf) in development of the retinal pigment epithelium (RPE) and in the stria vascularis of the inner ear. This will include the function of Mift in cell fate determination in the RPE and stria, its response to endothelial growth factors, and its role in modulating oxidative stress.