Retina-derived extracellular vesicles in diabetic retinopathy: their potential role in pathogenesis and therapy

糖尿病视网膜病变中视网膜来源的细胞外囊泡：它们在发病机制和治疗中的潜在作用

基本信息

批准号：
10644819
负责人：
Emma M Lessieur
金额：
$ 10.76万
依托单位：
UNIVERSITY OF CALIFORNIA-IRVINE
依托单位国家：
美国
项目类别：
财政年份：
2023
资助国家：
美国
起止时间：
2023-06-01 至 2025-05-31
项目状态：
未结题

项目摘要

Project summary. Extracellular vesicles are cell-derived membranous structures harboring a variety of biomolecules. Their secretion and cargo are determined in part by the physiological or pathological conditions that the parent cell is exposed to. Recently, increased levels of extracellular vesicles in plasma have been associated with the pathogenesis of diabetic retinopathy, but from where those plasma extracellular vesicles originated from, and whether they affect the development of the disease is still under investigation. Early in my postdoctoral training, I established a modified protocol to isolate extracellular vesicles from small tissues, including retina. Using this protocol, I isolated extracellular vesicles of retina explants from nondiabetic and diabetic mice and found that diabetic retina-derived extracellular vesicles induce ICAM-1, an important adhesion molecule, in retinal endothelial cells in vitro. This induction is inhibited by pharmacological blockage of TLR4, a transmembrane protein that has been proposed as an extracellular vesicles cell receptor. I also found that diabetic retina-derived extracellular vesicles activate circulating leukocytes isolated from nondiabetic animals. This work laid the foundation of my ongoing research. I want to determine the mechanism(s) of how retina-derived extracellular vesicles induce ICAM-1 in retinal endothelial cells and activate circulating leukocytes using a mouse model of diabetes. I propose 3 specific aims: Aim 1, To determine if a diabetes-modified visual cycle activity in photoreceptor cells modulates the retina- derived extracellular vesicles phenotype, which lead to the induction of ICAM-1 in retinal endothelial cells and activation of circulating leukocytes. Aim 2, To determine if TLR4 is the common receptor present in retinal endothelial cells and leukocytes and is triggered upon binding of retina-derived extracellular vesicles, leading to the induction of ICAM-1 in retinal endothelial cells and activation of circulating leukocytes in diabetes. Aim 3, To determine if rod-derived extracellular vesicles are key contributors to the retinal vascular pathology characteristic of diabetic retinopathy. These studies will be conducted in vivo using mice genetically deficient in key proteins of the visual cycle and pharmacological means to inhibit extracellular vesicles secretion and TLR4 receptor in diabetes. This proposal is novel because it focuses on (i) the role of retina (and rod)-derived extracellular vesicles in the pathogenesis of the retinopathy, (ii) the role of the visual cycle in the cargo sorting of retina (and rod)-derived extracellular vesicles, and (iii) the role of TLR4 as a receptor of retina (and rod)-derived extracellular vesicles. The insights learned from these studies can lead to the development of novel and effective targeted therapies to inhibit the etiopathogenesis of diabetic retinopathy.

项目总结。细胞外囊泡是细胞衍生的膜结构，含有多种生物分子。他们的分泌和货物部分取决于亲代细胞所处的生理或病理条件暴露于。最近，血浆中细胞外囊泡水平的增加与糖尿病视网膜病变的发病机制，但这些血浆细胞外囊泡的来源，以及它们是否影响疾病的发展仍在研究中。在博士后培训的早期，我建立了一个修改方案，从小细胞中分离出细胞外囊泡。组织，包括视网膜。使用该方案，我从非糖尿病患者中分离出视网膜外植体的细胞外囊泡和糖尿病小鼠，发现糖尿病视网膜来源的细胞外囊泡诱导 ICAM-1，这是一种重要的体外视网膜内皮细胞中的粘附分子。这种诱导被药理学阻断所抑制 TLR4 是一种跨膜蛋白，已被提议作为细胞外囊泡细胞受体。我还发现糖尿病视网膜来源的细胞外囊泡激活从非糖尿病患者分离的循环白细胞动物。这项工作为我正在进行的研究奠定了基础。我想确定其机制视网膜来源的细胞外囊泡在视网膜内皮细胞中诱导 ICAM-1 并激活循环白细胞使用糖尿病小鼠模型。我提出3个具体目标：目标 1，确定糖尿病改变的感光细胞视觉周期活动是否调节视网膜衍生的细胞外囊泡表型，导致视网膜内皮细胞中 ICAM-1 的诱导，激活循环白细胞。目标 2，确定 TLR4 是否是视网膜内皮细胞和白细胞中存在的常见受体，并且是否存在与视网膜来源的细胞外囊泡结合后触发，导致视网膜中 ICAM-1 的诱导糖尿病中的内皮细胞和循环白细胞的激活。目标 3，确定杆源性细胞外囊泡是否是视网膜血管病理的关键因素糖尿病视网膜病变的特征。这些研究将在体内进行，使用基因缺陷的小鼠，这些小鼠视觉周期的关键蛋白和药理手段抑制糖尿病细胞外囊泡分泌和TLR4受体。这个提议之所以新颖，是因为它重点关注（i）视网膜（和杆）来源的细胞外囊泡在发病机制中的作用视网膜病变的研究，（ii）视觉周期在视网膜（和视杆细胞）衍生的细胞外物质的货物分类中的作用 (iii) TLR4 作为视网膜（和杆）来源的细胞外囊泡受体的作用。见解从这些研究中学到的知识可以导致开发新颖有效的靶向疗法来抑制糖尿病视网膜病变的发病机制。