ISOPRENOID METABOLISM IN THE RETINA

这个项目的长期目标是阐明胆固醇和相关物质的生物学功能。 视网膜中的分子。RSH/Smith-Lemli-Opitz综合征(SLOS)，涉及7- 脱氢胆固醇(7DHC)转化为胆固醇。在一系列多个等距异常中首次发现 (MCA)综合征和合成代谢胆固醇途径缺陷，估计它是第四种最常见的 人类隐性疾病。SLOS有一种相关的视网膜变性，最近才被发现，但 这种退化的潜在机制尚不清楚。初步研究表明，氧化的参与 脂类和蛋白质，以及类固醇代谢和其他途径之间的“代谢串扰”。 通过转录调控。用相同酶的选择性抑制剂(AY9944)治疗大鼠 SLOS缺陷提供了一种动物模型，显示出进行性视网膜变性，影响两边 杆状和圆锥状。使用这个模型，与年龄和性别匹配的对照组大鼠相比，我们将使用 阐明疾病机制的三种不同的互补方法：1)微阵列分析 (基因组学)将揭示SLOS大鼠与对照视网膜的差异基因表达模式，确认靶点 采用实时荧光定量聚合酶链式反应和生化方法。2)脂质组学将揭示稳定- 国家正常和氧化的脂质水平，而3)蛋白质组学将识别数量和 这些动物视网膜中视网膜蛋白质的特定氧化修饰类型。此外， 光感受器细胞死亡的机制将使用与细胞凋亡相关的标准方法进行评估。这个 生物相容抗氧化剂(α-硫辛酸和EPC-K1)阻断脂质和蛋白质的能力 氧化和部分改善SLOS大鼠视网膜退行性变将在两项下进行评估 正常和“轻微损坏”状态。通过这种方式，对视网膜机制的基本新见解 将获得与SLOS相关的退化。这些研究也可能为使用 抗氧化剂作为胆固醇补充的补充，目前(如果不完美)的治疗策略 SLOS患者管理。后者已被证明可以改善SLOS大鼠的光感受器功能 模特。因此，该项目支持NEI开发挽救视力的治疗方法的使命，减少 视力障碍和失明，并提高所有年龄段的生活质量。

The long-range goal of this project is to elucidate the biological functions of cholesterol and related molecules in the retina. The RSH/Smith-Lemli-Opitz Syndrome (SLOS), involves defective conversion of 7- dehydrocholesterol (7DHC) to cholesterol. The first discovered in a series of multiple congential anomalies (MCA) syndromes and anabolic cholesterol pathway defects, it is estimated to be the fourth most common human recessive disease. SLOS has an associated retinal degeneration, discovered only recently, but the mechanism underlying the degeneration is unknown. Initial studies suggest the involvement of oxidized lipids and proteins, as well as "metabolic cross-talk" between sterol metabolism and other pathways, likely via transcriptional regulation. Treating rats with a selective inhibitor (AY9944) of the same enzyme that is defective in SLOS affords an animal model that exhibits a progressive retinal degeneration affecting both rods and cones. Using this model, in comparison with age- and sex-matched control rats, we will employ three different, complimentary approaches to elucidating the disease mechanism: 1) Microarray analysis (genomics) will reveal differential gene expression patterns in SLOS rat vs: control retinas, confirming targets by real-time PCR and biochemical methods. 2) Lipidomics will reveal quantitative differences in the steady- state levels of normal and oxidized lipids, while 3) proteomics will identify differences in the amounts and types of specific oxidative modifications of retinal proteins in retinas of these animals. In addition, the mechanism of photoreceptor cell death will be assessed using standard methods relevant to apoptosis. The ability of biologically compatible antioxidants (alpha-lipoic acid and EPC-K1) to block lipid and protein oxidation and to partially ameliorate the retinal degenerationln in SLOS rats will be assessed, under both normal and "light-damage" conditions. In this way, fundamental new insights into the mechanism of retinal degeneration associated with SLOS will be obtained. These studies also may provide support for the use of antioxidants as adjuncts to cholesterol supplementation, the current (if imperfect) therapeutic strategy for SLOS patient management. The latter has been shown to improve photoreceptor function in the SLOS rat model. As such, this project supports the NEI's mission of developing sight-saving treatments, reducing visual impairment and blindness, and improving the quality of life for people of all ages.