Aberrant RPE mTORC1 signaling in dysregulation of choroid homeostasis

异常 RPE mTORC1 信号传导导致脉络膜稳态失调

基本信息

批准号：
10680452
负责人：
Yan Chen
金额：
$ 36.25万
依托单位：
UNIVERSITY OF OKLAHOMA HLTH SCIENCES CTR
依托单位国家：
美国
项目类别：
财政年份：
2016
资助国家：
美国
起止时间：
2016-08-01 至 2026-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10680452
关键词：
Age related macular degeneration Aging Angiopoietin-2 Atrophic Blindness Blood Vessels Bruch&apos s basal membrane structure CMV promoter Cell Separation Choroid Clinical Complex DARPP Data Defect Deposition Digestion Disease Disease Progression Docking Dropout Drusen Elderly Endothelial Cells Epithelial Cells Event Eye FRAP1 gene Fatty Acids Flow Cytometry Functional disorder Genes Genetic Genetic Variation Goals Histopathology Homeostasis Human Hyperactivity Impairment Inflammation Integrins Knock-out Knockout Mice Link Lipids Literature Measures Mediating Metabolic Molecular Mus Neurons PECAM1 gene Pathologic Pathway interactions Persons Phagocytosis Phosphoproteins Phosphorylation Photoreceptors Predisposition Production Proto-Oncogene Proteins c-akt Research Retina Side Signal Pathway Signal Transduction Signaling Protein Stress Structure of retinal pigment epithelium TEK gene TIE-2 Receptor TSC1 gene Testing Therapeutic Intervention Thinness Tissues Up-Regulation Virus age related aged autocrine cytokine extracellular vesicles functional loss gain of function glucose metabolism induced pluripotent stem cell insight lipid metabolism mouse model novel ophthalmic examination overexpression prevent subretinal injection uptake

Age related macular degeneration Aging Angiopoietin-2 Atrophic Blindness Blood Vessels Bruch&apos s basal membrane structure CMV promoter Cell Separation Choroid Clinical Complex DARPP Data Defect Deposition Digestion Disease Disease Progression Docking Dropout Drusen Elderly Endothelial Cells Epithelial Cells Event Eye FRAP1 gene Fatty Acids Flow Cytometry Functional disorder Genes Genetic Genetic Variation Goals Histopathology Homeostasis Human Hyperactivity Impairment Inflammation Integrins Knock-out Knockout Mice Link Lipids Literature Measures Mediating Metabolic Molecular Mus Neurons PECAM1 gene Pathologic Pathway interactions Persons Phagocytosis Phosphoproteins Phosphorylation Photoreceptors Predisposition Production Proto-Oncogene Proteins c-akt Research Retina Side Signal Pathway Signal Transduction Signaling Protein Stress Structure of retinal pigment epithelium TEK gene TIE-2 Receptor TSC1 gene Testing Therapeutic Intervention Thinness Tissues Up-Regulation Virus age related aged autocrine cytokine extracellular vesicles functional loss gain of function glucose metabolism induced pluripotent stem cell insight lipid metabolism mouse model novel ophthalmic examination overexpression prevent subretinal injection uptake

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项目摘要

The overall goal of the project is to delineate the cellular and molecular mechanisms that link dysfunction of the retinal pigment epithelium (RPE) to degeneration of the choriocapillaris (CC). Choroidal atrophy is an early pathological change in age-related macular degeneration (AMD), a leading cause of blindness in elderly people. The RPE produces a number of trophic factors that support the structural integrity of the choroidal vasculature. Aging and age-related degeneration can interfere with the functional interactions between the RPE and CC. The underlying disease mechanisms are largely unclear. We found that the mouse model of RPE-specific overactivation of the mechanistic target of rapamycin complex 1 (mTORC1) recapitulated many of the clinical features of CC dropout. RPE cells with high mTORC1 activity had increased release of angiopoietin 2 (ANGPT2), a vascular destabilizing factor that is usually produced by endothelial cells (ECs) and exerts autocrine effects on its receptor TIE2. We further identified that the secretion of ANGPT2 from RPE was likely mediated by the upregulation and activation of a phosphoprotein DARPP-32. Based on these novel findings, we hypothesize that ANGPT2 production and secretion from the RPE contribute to the degeneration of choroid under pathological conditions that involve dysregulated mTORC1 signaling. The hypothesis will be tested in three specific aims. Aim 1 is to determine whether mTORC1 activation in the RPE will stimulate ANGPT2 secretion via DARPP-32-dependent mechanisms. Aim 2 is to examine whether ANGPT2 can regulate the function of choroidal ECs via TIE2-dependent or independent pathways. Aim 3 is to determine whether genetic knockout of ANGPT2 in the RPE, or AAV-mediated overexpression of ANGPT2 will influence the CC atrophy in the mouse model of mTORC1 hyperactivation. The results from these studies will provide insights on how the AMD-related signaling events in the RPE impact its support to the CC. The newly identified ANGPT2-TIE2 axis between the RPE and choroidal ECs can be a molecular pathway for the therapeutic intervention of choroidal atrophy.

该项目的总体目标是描述连接的细胞和分子机制视网膜色素上皮（RPE），脉络膜毛细血管（CC）的变性。脉络膜萎缩是早期的年龄相关黄斑变性（AMD）的病理变化，这是老年失明的主要原因人们。 RPE产生许多支持脉络膜结构完整性的营养因素脉管系统。衰老和与年龄相关的变性会干扰 RPE和CC。潜在的疾病机制在很大程度上不清楚。我们发现鼠标模型雷帕霉素复合物1（MTORC1）的机械靶标的RPE特异性过度活化概括了许多 CC辍学的临床特征。具有高MTORC1活性的RPE细胞增加了血管生成素2（Angpt2），一种血管不稳定因子，通常由内皮细胞（ECS）产生并对其受体TIE2发挥自分泌作用。我们进一步确定了rpe的angpt2分泌可能是由磷酸蛋白Darpp-32的上调和激活介导的。基于这些小说调查结果，我们假设RPE的Angpt2产生和分泌有助于退化在病理条件下的脉络膜涉及MTORC1信号失调的病理条件下。假设将是以三个特定目标进行测试。 AIM 1是确定RPE中的MTORC1激活是否会刺激通过DARPP-32依赖性机制的Angpt2分泌。 AIM 2是检查Angpt2是否可以通过TIE2依赖性或独立途径来调节脉络膜EC的功能。目标3是确定 RPE中ANGPT2的遗传敲除还是AAV介导的ANGPT2的过表达会影响 MTORC1过度激活小鼠模型中的CC萎缩。这些研究的结果将提供关于RPE中与AMD相关的信号事件如何影响CC的洞察力。新确定的 RPE和脉络膜EC之间的Angpt2-Tie2轴可以是治疗性的分子途径脉络膜萎缩的干预。