Comparative Genomics of Glaucoma

描述（由申请人提供）：我们的长期目标是确定在某些形式青光眼发展的早期阶段经历转录调控改变的基因集合，并在大量人群中确定这些基因的多态性，这些基因可能使携带这些基因的个体易患该疾病。青光眼是全球可逆性失明的主要可治疗原因，影响着6000多万人。然而，在大多数人群中，易患青光眼的遗传因素在很大程度上仍然是未知的。之前，我们建立了黑腹果蝇作为研究人类青光眼相关的“小梁网诱导糖皮质激素反应”蛋白（也称为心肌蛋白；TIGR/MYOC）影响的模型系统，并确定了当TIGR/MYOC在果蝇眼睛中过表达时上调或下调的转录本。果蝇作为一种通用的遗传模型仍然是无与伦比的，它可以作为一种快速的基因发现系统，其中转录谱分析可以识别当候选青光眼基因在果蝇眼中表达时经历改变的基因。在确定了这些基因的人类同源基因后，我们可以问，当通过腺病毒引入TIGR/MYOC（或其他候选青光眼基因）时，其中哪些基因在灌注的死后人眼中的表达发生了变化。然后，我们将研究通过这两步筛选涉及的候选基因的多态性是否与西非人群中青光眼的发病率有关。本提案的具体目的是：(1)“通过靶向过表达TIGR/MYOC突变体和靶向RNAi介导的TIGR/心肌调节基因下调来评估果蝇的眼部表型，并分析和比较转基因菌株之间的转录改变；(2)评估先前和在Specific Aim 1中发现的果蝇基因的人类同源物，在过度表达TIGR/MYOC或其他新的候选青光眼基因的灌注死后人眼中是否上调或下调；(3)评估新的青光眼候选基因多态性是否与高眼压和青光眼在西非高发人群中的发病率相关。这些实验代表了发现候选疾病易感基因的新策略，并将为未来大规模基因组SNP研究奠定基础，以确定可能传递青光眼易感性的基因的完整补充。

DESCRIPTION (provided by applicant): Our long-term goal is to identify ensembles of genes that undergo altered transcriptional regulation during the early stages of the development of some forms of glaucoma, and to identify in the human population at large polymorphisms in such genes that may predispose individuals who harbor them to the development of the disease. Glaucoma is the leading treatable cause of irreversible blindness worldwide and affects more than 60 million people. The genetic factors that predispose to glaucoma in the population at large remain, however, largely unknown. Previously, we established Drosophila melanogaster as a model system for studies of the effects of the human glaucoma-associated "trabecular meshwork inducible glucocorticoid response" protein (also known as myocilin; TIGR/MYOC) and identified transcripts that are up- or down-regulated when TIGR/MYOC is overexpressed in the Drosophila eye. Drosophila remains unsurpassed as a versatile genetic model, which can be used as a rapid gene discovery system, in which transcriptional profiling can identify genes that undergo altered regulation when candidate glaucoma genes are expressed in the Drosophila eye. After identifying human orthologues of such genes we can ask which of them show alterations in their expression in perfused post mortem human eyes when TIGR/MYOC (or other candidate glaucoma genes) are introduced via an adenovirus. We will then investigate whether polymorphisms in candidate genes implicated via this two-step screen are linked to the incidence of glaucoma in a West-African human population. The specific aims of this proposal are to: (l)'Assess the ocular phenotypes of flies with targeted overexpression of TIGR/MYOC mutants and targeted RNAi mediated downregulation of TIGR/MYOC-modulated genes and perform analyses and comparisons of transcriptional alterations among transgenic strains; (2) Assess whether human homologues of Drosophila genes, discovered previously and in Specific Aim 1, are up- or down-regulated in perfused post mortem human eyes subjected to overexpression of TIGR/MYOC, or of other new candidate glaucoma genes; and, (3) Evaluate whether polymorphisms in new candidate glaucoma genes are associated with ocular hypertension and the incidence of glaucoma in a West-African population with high incidence of the disease. These experiments represent a novel strategy for candidate disease susceptibility gene discovery and will lay the foundation for future large scale genomic SNP studies to identify the full complement of genes that may convey susceptibility to glaucoma.