Modulation of retinoid reactivity and pathological signaling in retinal therapeutics

视网膜治疗中类维生素A反应性和病理信号的调节

• 批准号: 10454758
• 负责人: Philip David Kiser
• 金额: --
• 依托单位: VETERANS HEALTH ADMINISTRATION
• 依托单位国家: 美国
• 财政年份: 2020
• 资助国家: 美国
• 起止时间: 2020-04-01 至 2024-03-31
• 项目状态: 已结题
• 来源: https://reporter.nih.gov/project-details/10454758
• 关键词: 11-cis-Retinol; Age; Age related macular degeneration; Alcohols; Aldehydes; Anabolism; Animal Model; Apoptotic; Binding; Biochemical; Biological; Biology; Blindness; Cell Death; Cells; Ceramides; Chemically Induced Toxicity; Chemicals; Color; Color Visions; Cone; Crystallization; Data; Development; Disease; Disease Progression; Dissociation; Dose; Elderly; Enzymes; Esterification; Exhibits; Exposure to; Functional Imaging; Funding; G Protein-Coupled Receptor Signaling; G-Protein-Coupled Receptors; Goals; Hand; Health; Health Care Costs; Healthcare Systems; High Prevalence; Hour; Human; Image; Imaging Techniques; Individual; Knock-in Mouse; Knock-out; Lead; Light; Link; Lipofuscin; LoxP-flanked allele; Mediating; Mediator of activation protein; Metabolism; Modeling; Modernization; Muller' s cell; Mus; Natural regeneration; Nonexudative age-related macular degeneration; Opsin; Pathogenesis; Pathologic; Pathway interactions; Pharmaceutical Preparations; Pharmacodynamics; Pharmacology; Phosphodiesterase Inhibitors; Photoreceptors; Play; Predisposition; Process; Production; Property; Proteins; RPE65 protein; Reaction; Research; Retina; Retinal Cone; Retinal Diseases; Retinal Pigments; Retinaldehyde; Retinoids; Role; Signal Transduction; Site; Structure; Structure of retinal pigment epithelium; System; Testing; Therapeutic; Therapeutic Agents; Tissues; Toxic effect; Transgenic Mice; Translating; Veterans; Vision; Visual; Visual Perception; Visual impairment; Vitamin A; adduct; base; central visual field; chromophore; cis trans isomerization; clinical application; conditional knockout; desaturase; design; dihydroceramide; disability; effective therapy; geographic atrophy; in vitro testing; in vivo; inhibitor; loss of function; military veteran; mouse model; next generation; novel; novel therapeutics; phosphoric diester hydrolase; protective effect; rational design; retinol isomerase; single-cell RNA sequencing; small molecule; visual cycle

Project Summary Age-related macular degeneration is a principal cause of vision loss in individuals over the age of 60 years including Veterans. It is characterized by a loss of sight in the central visual field where sharp, polychromatic images are generated under the bright light conditions that modern humans are typically exposed to during waking hours. Loss of this high acuity color vision leads to significant disability. The high prevalence of AMD places a large burden on the healthcare system with upwards of 98 billion dollars spent yearly on AMD-related healthcare costs in the US. Currently, there are no highly effective treatments for the most common form of the disease, known as geographic atrophy, which makes up ~90% of advanced AMD. During the past VA funding period, we studied inhibition of the visual cycle as a potential treatment for AMD and characterized enzymes proposed to contribute to the normal function of the visual cycle pathway. Based on key findings we made during the initial funding period, we now propose to investigate related pathways that are tied to the pathogenesis of AMD through the involvement of retinaldehyde (RAL) derived from the visual cycle. Additionally, we will continue our studies on an enzyme known as Des1 that has been proposed to mediate the regeneration of cone visual pigments, the color sensing molecules in the central retina. We will explore these pathways through the following Specific Aims: 1. Elucidate biological roles for Des1 within the RPE using novel RPE- specific Cre mice. Previously, we showed that Des1 protein in Müller cells is not a major contributor to 11-cis- retinol synthesis for cone photoreceptors. However, single cell RNA-Seq analysis revealed that the RPE is the principal site of Des1 expression in the retina raising questions about its biological role in this tissue. Using a validated floxed Des1 mouse model, we will investigate the impact of Des1 loss of function on RPE and photoreceptor health and visual cycle function by crossing these mice with RPE-specific Cre mice and characterizing them using a variety of functional and imaging techniques. Des1 also plays a key role in de novo ceramide production, a known mediator of apoptotic RPE cell death. We hypothesize that Des1 deletion in the RPE will modulate susceptibility of the tissue to chemical-induced toxicity, which serves as a model for RPE cell death that occurs in geographic atrophy. These studies will test the viability of Des1 as a potential target for AMD therapeutics. 2. Advance next-generation visual cycle modulators (VCMs) with selective pharmacodynamics. Visual cycle modulators were originally designed to inhibit RPE65 in order to suppress pathological lipofuscin accumulation and slow retinal disease progression. We discovered a novel mechanism of action for these compounds: direct reaction with RAL released from activated visual opsins to limit formation of pathological RAL adducts. We have generated visual cycle modulators with preferential activity towards RAL sequestration that possess protective effects against retinopathy with reduced effects on visual cycle activity. Based on our initial studies, we propose to synthesize and characterize a new set of rationally-designed visual cycle modulators that we hypothesize will possess augmented therapeutic activity and diminished visual cycle suppression. 3. Develop phosphodiesterase (PDE) inhibition as a treatment for retinal disease. Prior research has implicated aberrant GPCR signaling in RAL toxicity. Phosphodiesterase enzymes are major effectors and regulators of GPCRs and have been successfully targeted for clinical applications. We hypothesize that inhibitors of PDEs will confer protective effects against retinal insults without impairing visual function. Our preliminary data indicates that PDE4 inhibitors are particularly effective at low doses in animal models of RAL toxicity. We will screen these compounds and related derivatives to elucidate their site and mechanism of protective action using animal models of retinopathy. Together, these studies may uncover small molecules that could readily be translated into retinal disease treatments for veterans.

项目摘要 与年龄相关的Macualar变性是60岁以上个人视力丧失的主要原因 包含退伍军人。 图像是在现代人类通常会暴露在的明亮光线下产生的 损失这种色彩视觉会导致巨大的残疾。 在医疗保健系统上承担着很大的负担，在与AMD相关的一年中花费了980亿美元 美国目前的医疗费用。 疾病，被称为地理萎缩，在过去的VA资金中占晚期AMD的90％。 时期，我们研究了对视觉周期的抑制作用，作为对AMD的潜在治疗和表征酶的抑制作用 基于我们在我们期间做出的关键发现，有助于视觉周期的正常功能 最初的资金期，我们现在建议研究与相关的途径，该途径与 通过从视觉循环中得出的视网膜醛（RAL）的涉及到AMD。 继续我们对称为DES1的酶的研究，该酶已提出介导锥体的再生 视觉颜料，中央视网膜中的颜色传感分子。 以下特定目的：1。阐明DES的生物学作用 特定的Cre小鼠。 但是，锥形光感受器的视网膜合成。 视网膜中DES1表达的主要部位提出有关该组织中的生物学作用。 经过验证的Floxed DES1小鼠模型，我们将研究DES1功能丧失对RPE的影响 光感受器的健康和视觉周期功能通过用RPE特异性CRE小鼠跨越小鼠和视觉周期功能 表征多种功能和成像技术。 神经酰胺的生产，一种已知的凋亡RPE细胞死亡的介体。 RPE将调节组织对化学诱导的毒性的敏感性，作为RPE细胞的模型 在地理萎缩中发生的死亡。 治疗方法。 最初设计的视觉周期调节剂在Hibit RPE65中抑制RPE65 病理脂肪素的积累和视网膜疾病的进展缓慢。 化合物的作用：与激活的视觉视觉蛋白的直接反应，以限制形成 病理性添加物。 对视网膜病具有保护作用的隔离，对视觉周期活动的影响降低。 根据我们的初步研究，我们建议合成并表征一组新的经过精心设计的视觉 我们假设的循环调节器将具有增强的治疗活性并减少视觉周期 Suppness。3。发展为视网膜疾病的磷酸二酯酶（PDE）。 先前的研究暗示了RAL TOXIAL中的异常GPCR信号传导。 GPCR的效应子和调节剂已成功地用于临床应用 PDE的抑制剂将赋予对视网膜损伤的保护作用，而不会损害视觉功能。 我们的初步数据表明PDE4抑制剂在低剂量的动物模型中特别有效 ral toxity。我们将筛选这些化合物和相关的衍生物 使用视网膜病变的动物模型，这些研究可能会发现小分子 可以轻易地翻译成退伍军人的视网膜疾病治疗。