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: 10618853
• 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/10618853
• 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; Data; Development; Disease; Disease Progression; Dissociation; Dose; Drug Modulation; Elderly; Enzymes; Esterification; Exhibits; Exposure to; 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; Metabolism; Modeling; Modernization; Muller' s cell; Mus; Natural regeneration; Nonexudative age-related macular degeneration; Opsin; Pathogenesis; Pathologic; Pathway interactions; Pharmaceutical Preparations; Pharmacodynamics; 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; absorption; adduct; central visual field; chromophore; cis trans isomerization; clinical application; conditional knockout; desaturase; design; dihydroceramide; disability; effective therapy; geographic atrophy; human old age (65+); in vitro testing; in vivo; inhibitor; loss of function; military veteran; mouse model; next generation; novel; novel therapeutics; pharmacologic; 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 黄斑变性是60岁以上人群视力丧失的主要原因 包括退伍军人。它的特点是视力丧失的中央视野，其中尖锐，多色 图像是在现代人通常暴露于的明亮光线条件下产生的 醒着的时间这种高敏锐度色觉的丧失会导致严重的残疾。AMD的高患病率 给医疗保健系统带来了巨大的负担，每年花费在AMD相关的医疗保健上的费用超过980亿美元。 美国的医疗费用。目前，对于最常见的糖尿病形式，还没有高效的治疗方法。 这种疾病称为地图状萎缩，占晚期AMD的约90%。在过去的融资中， 期间，我们研究了抑制视觉周期作为AMD的潜在治疗方法，并表征了酶 建议有助于视觉循环通路的正常功能。根据我们在研究期间的主要发现， 在最初的资助期间，我们现在建议研究与疾病发病机制相关的相关途径。 AMD通过视网膜醛（RAL）的参与而衍生出视觉周期。此外，我们将 继续我们对一种名为Des 1的酶的研究，该酶被认为可以介导视锥细胞的再生 视色素，即视网膜中央的颜色感知分子。我们将探索这些途径，通过 具体目标：1。使用新型RPE阐明Des 1在RPE中的生物学作用- Cre小鼠。以前，我们表明Müller细胞中的Des 1蛋白不是11-顺式- 用于视锥光感受器的视黄醇合成。然而，单细胞RNA-Seq分析显示，RPE是 Des 1在视网膜中表达的主要位点引起了关于其在该组织中的生物学作用的问题。使用 通过验证floxed Des 1小鼠模型，我们将研究Des 1功能丧失对RPE的影响， 通过将这些小鼠与RPE特异性Cre小鼠杂交， 使用各种功能和成像技术来表征它们。Des 1也在de novo中起着关键作用 神经酰胺的产生，一种已知的凋亡性RPE细胞死亡的介质。我们假设，Des 1基因的缺失， RPE将调节组织对化学诱导的毒性的敏感性，其用作RPE细胞的模型。 发生在地图状萎缩中的死亡。这些研究将测试Des 1作为AMD潜在靶点的可行性 治疗学2.先进的下一代视觉周期调节器（VCM）， 药效学视觉周期调节剂最初被设计为抑制RPE 65，以抑制 病理性脂褐素积累和缓慢的视网膜疾病进展。我们发现了一种新的机制 这些化合物的作用：与从活化视蛋白释放的RAL直接反应，以限制 病理性RAL加合物。我们已经产生了对RAL具有优先活性的视觉周期调节剂 隔离，其对视网膜病变具有保护作用，对视觉周期活动具有降低的作用。 基于我们的初步研究，我们建议合成和表征一组新的合理设计的视觉 周期调节剂，我们假设将拥有增强的治疗活性和减少视觉周期 镇压3.开发磷酸二酯酶（PDE）抑制剂作为视网膜疾病的治疗方法。 先前的研究表明RAL毒性中存在异常的GPCR信号传导。磷酸二酯酶是主要的 GPCR的效应子和调节子，并已成功靶向临床应用。我们假设 PDE的抑制剂将赋予针对视网膜损伤的保护作用而不损害视觉功能。 我们的初步数据表明，PDE 4抑制剂在低剂量下在动物模型中特别有效。 RAL毒性。我们将筛选这些化合物和相关衍生物，以阐明它们的作用部位和作用机制。 使用视网膜病动物模型的保护作用。总之，这些研究可能会发现小分子， 可以很容易地转化为退伍军人的视网膜疾病治疗。