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cGAS-STING signaling in diabetic retinopathy

糖尿病视网膜病变中的 cGAS-STING 信号传导

基本信息

批准号：
10610331
负责人：
Jian-Xing Ma
金额：
$ 38.75万
依托单位：
WAKE FOREST UNIVERSITY HEALTH SCIENCES
依托单位国家：
美国
项目类别：
财政年份：
2022
资助国家：
美国
起止时间：
2022-05-01 至 2027-04-30
项目状态：
未结题

来源：
https://reporter.nih.gov/project-details/10610331
关键词：
Ablation Address Adhesions Agonist Animal Model Antiinflammatory Effect Attenuated Blood Vessels Blood capillaries Capillary Endothelial Cell Cells Clinical Research Cyclic GMP Data Diabetes Mellitus Diabetic Retinopathy Diabetic mouse Down-Regulation Exposure to Extravasation Fenofibrate Gene Activation Genus Hippocampus Human Impairment In Vitro Inflammation Inflammatory Knockout Mice Knowledge Leukocytes Leukostasis Measures Mediating Mitochondria Mitochondrial DNA Modeling Mus Oral PPAR alpha Pathogenesis Pathogenicity Pathology Pathway interactions Permeability Phagocytosis Pharmaceutical Preparations Phosphorylation Play Regulation Reporting Retina Retinal Diseases Role Signal Transduction Stimulator of Interferon Genes Therapeutic Effect Transfection Transgenic Mice Transgenic Organisms Type 2 diabetic Up-Regulation clinically relevant diabetic diabetic patient immune activation immunoregulation inhibitor migration mitochondrial genome monocyte new therapeutic target non-diabetic novel overexpression prospective response stressor targeted treatment

项目摘要

PROJECT SUMMARY/ABSTRACT Retinal leukostasis and vascular leakage play important pathogenic roles in diabetic retinopathy (DR). Accumulating evidence suggests that DR is not an isolated retinal disease. Although circulating monocytes are the major leukocyte subset responsible for leukostasis, the underlying regulation for monocyte activation in DR has not been well investigated, which represents a knowledge gap. Two independent and prospective clinical studies reported that fenofibrate, an agonist of peroxisome proliferator-activated receptor alpha (PPARα), has robust therapeutic effects on DR. Our preliminary studies showed that PPARα levels are down-regulated in circulating monocytes of diabetic patients and diabetic animal models. PPARα ablation alone induces monocyte activation, including increased adhesion, migration, and phagocytosis, while fenofibrate attenuates monocyte activation in diabetic mice. The cyclic GMP-AMP synthase (cGAS)-stimulator of interferon genes (STING) pathway plays a crucial role in inflammation. We showed that cGAS and STING are up-regulated in monocytes in a diabetic model and in PPARα-/- mice, and inhibition of STING attenuates monocyte activation and alleviates retinal leukostasis. Therefore, we hypothesize that PPARα suppresses cGAS-STING signaling to alleviate monocyte activation and retinal leukostasis in DR, and that this effect is mediated in part by the mitoprotective function of PPARα in diabetic monocytes. To address this hypothesis, we will first investigate if PPARα suppresses monocyte activation in diabetes to alleviate retinal inflammation and vascular leakage in DR. Using monocyte-specific PPARα conditional KO (PPARαMCKO) mice and monocyte-specific PPARα transgenic (PPARαMCTg) mice, we will determine if ablation of PPARα will exacerbate, while PPARα over-expression will alleviate diabetes-induced monocyte activation (adhesion, migration, phagocytosis), retinal leukostasis, vascular leakage, and acellular capillary formation. Toward the mechanism for the monocyte-regulating function of PPARα, we will investigate if the anti-inflammatory effect of PPARα is through inhibition of cGAS-STING signaling in monocytes in diabetes. We will compare cGAS-STING activation in monocytes of diabetic PPARαMCKO, PPARαMCTg, and WT mice. Furthermore, we will investigate if PPARα ablation promotes cGAS- STING activation in monocytes by exacerbating mitochondrial damage and cytosolic mtDNA release in DR. We also propose to study if the cGAS-STING pathway activation in monocytes plays a causative role in retinal inflammation and vascular leakage in DR. We will determine if a STING inhibitor or ablation of cGAS or STING will ameliorate monocyte activation, retinal leukostasis and vascular leakage in diabetic mice. The proposed studies will identify a novel interaction between PPARα and the cGAS-STING pathway in the regulation of immunometabolism and retinal inflammation in DR. These studies will also elucidate a new mechanism responsible for the therapeutic effects of fenofibrate on DR.

项目总结/文摘