A New LCA Model By Polarity Gene Ablation

极性基因消融的新 LCA 模型

基本信息

批准号：
8073470
负责人：
Seo-Hee Cho
金额：
$ 32.4万
依托单位：
UNIVERSITY OF TEXAS HLTH SCI CTR HOUSTON
依托单位国家：
美国
项目类别：
财政年份：
2010
资助国家：
美国
起止时间：
2010-06-01 至 2012-01-06
项目状态：
已结题

来源：
https://reporter.nih.gov/project-details/8073470
关键词：
Ablation Adhesions Adult Affect American Animal Model Apical Apoptotic Architecture Biological Biological Assay Birth Blindness Bromodeoxyuridine Cell Proliferation Cell Therapy Cell Transplantation Cells Ciliary epithelium Cleaved cell Clinical Complex Defect Degenerative Disorder Detection Development Disease Disease Progression Drosophila genus Electroretinography Embryo Embryonic Development Epithelial Cells Event Exhibits Eye Financial compensation Generations Genes Genetic Goals Homologous Gene Human Induced Mutation Inherited Integral Membrane Protein Investigation Knock-out Knockout Mice Lead Leber&apos s amaurosis Lesion Mediating Membrane Proteins Modeling Molecular Mus Mutation Neuroglia Pathogenesis Pathologic Pathology Patients Perinatal Phenocopy Phenotype Photoreceptors Proteins Recovery Research Project Grants Retina Retinal Retinal Degeneration Retinal Diseases Retinal Dystrophy Retinitis Pigmentosa Role Sensory Staging Stem cell transplant Stem cells TdT-Mediated dUTP Nick End Labeling Assay Testing Therapeutic Therapeutic Intervention Tight Junctions Tissues Transplantation Vision Visual impairment Work apical membrane base caspase-3 embryo tissue fetal insight migration mouse genome mouse model mutant neurogenesis neuropathology novel null mutation photoreceptor degeneration postnatal premature protein complex protein function public health relevance relating to nervous system research study response retinal progenitor cell stem cell therapy subretinal injection young adult

项目摘要

DESCRIPTION (provided by applicant): Human LCA, the most severe form of degenerative retinal disease, is thought to be caused by abnormal differentiation or extremely premature degeneration of photoreceptor cells. However, with the exception of a very few types, little is known about the mechanisms underlying the developmental defects of LCA, mainly due to limited access to human embryonic LCA tissues and the lack of suitable animal models that faithfully recapitulate the various phenotypes of heterogeneous LCA diseases. LCA8, an inherited retinal dystrophy that begins during the fetal stages, is caused by mutations in Crb1, one of the three mammalian homologues of Drosophila Crumbs. Unexpectedly, the Crb1 knock-out mouse does not recapitulate human LCA8, most likely due to functional compensation by the closely related homologues Crb2 and Crb3. Because CRB and PALS1, a bona-fide CRB interacting partner, are functionally interdependent, and Pals1 exists as a single gene in the mouse genome, we hypothesize that deleting Pals1 will completely inhibit the function of the CRB proteins, thus phenocopying the Crb1 null mutations identified in LCA8 patients. In this study, we propose to create a conditional knock-out of Pals1 in mice to establish a human LCA8-like mouse model to elucidate disease-causing mechanisms at the cellular and molecular levels during embryonic development and adult stages. Furthermore, we will attempt to rescue the Pals1-deficient retinas via perinatal transplantation of retinal stem cells. Preliminary results show that Pals1CKO retinas exhibit novel embryonic phenotypes such as increased retinal cell proliferation and disorganized retinal lamination as well as postnatal LCA8-like phenotypes, including severe photoreceptor degeneration and concomitant loss of ERG in young adults. This project will establish the novel concept that the loss of Pals1 function in retinal progenitor cells is a causative pathologic event that leads directly to the establishment of LCA lesions. In addition, this research project will greatly enhance the understanding of PALS1 and CRB polarity complex protein function in the developing retina and the role of polarity gene defects during LCA8 development. Furthermore, the early developmental defects induced in Pals1CKO mice provide a unique opportunity to test the feasibility of and to optimize perinatal cell transplantation therapy, which offers a promising approach to restoring the vision lost during development by replacing diseased cells with normal retinal stem cells. PUBLIC HEALTH RELEVANCE: Abnormalities in the retinal development often cause devastating diseases like degenerative retinal diseases, which collectively affects more than 10 million Americans. Generation of new mouse model for LCA, the most severe, untreatable, incurable, inherited degenerative retinal disorder, would help not only the understanding the normal development of the retina, but also the disease causing mechanisms that may ultimately lead to the potential therapeutic interventions. Cell transplantation strategy using amplified retinal stem cells to restore the vision of new LCA mouse model will provide a new insight into the development of clinical therapy for human LCA patients.

描述（由申请人提供）：人类LCA是退化性视网膜疾病最严重的形式，被认为是由异常分化或光感受器细胞过早变性引起的。但是，除了很少的类型外，对LCA发育缺陷的基础机制知之甚少，这主要是由于获得人类胚胎LCA组织的访问有限，并且缺乏合适的动物模型，这些动物模型忠实地概括了异构LCA疾病的各种表型。 LCA8是一种从胎儿阶段开始的遗传性视网膜营养不良，是由CRB1突变引起的，CRB1是果蝇的三个哺乳动物同源物之一。出乎意料的是，CRB1敲除小鼠不会概括人LCA8，这很可能是由于密切相关的同源物CRB2和CRB3的功能补偿所致。由于CRB和PALS1是一个真正的CRB相互作用伴侣，在功能上是相互依存的，并且PALS1作为小鼠基因组中的单个基因存在，因此我们假设删除PALS1将完全抑制CRB蛋白的功能，从而在LCA8患者中鉴定出CRB1 NULL突变。在这项研究中，我们建议在小鼠中创建一个有条件的PALS1敲除，以建立人类LCA8样小鼠模型，以在胚胎发育和成人阶段阐明在细胞和分子水平上阐明引起疾病的机制。此外，我们将尝试通过视网膜干细胞的围产期移植来挽救PALS1缺陷视网膜。初步结果表明，PALS1CKO视网膜表现出新颖的胚胎表型，例如增加的视网膜细胞增殖和混乱的视网膜层压以及产后LCA8样表型，包括严重的光感受器退化和年轻人的ERG损失。该项目将建立一个新的概念，即视网膜祖细胞中PALS1功能的丧失是一种致病性病理事件，直接导致LCA病变的建立。此外，该研究项目将大大增强对PALS1和CRB极性复杂蛋白功能在发育中的视网膜中的理解以及LCA8发育过程中极性基因缺陷的作用。此外，PALS1CKO小鼠引起的早期发育缺陷为测试和优化围产期细胞移植疗法的可行性和优化的独特机会提供了独特的机会，该疗法提供了一种有希望的方法，可以通过用正常视网膜干细胞代替患病的细胞来恢复发育中丧失的视力。公共卫生相关性：视网膜发展的异常情况通常会导致诸如退化性视网膜疾病之类的毁灭性疾病，这共同影响了超过1000万美国人。 LCA的新小鼠模型的产生是最严重，不可治疗，无法治愈的，遗传性的退化性视网膜疾病，不仅有助于理解视网膜的正常发育，而且还将有助于导致可能导致潜在的治疗干预措施的疾病。使用放大视网膜干细胞恢复新LCA小鼠模型的视力的细胞移植策略将为人类LCA患者的临床治疗发展提供新的见解。