# A new pathogenic mechanism for diabetic retinopathy > **NIH NIH R01** · WAKE FOREST UNIVERSITY HEALTH SCIENCES · 2024 · $474,114 ## Abstract Diabetes-induced retinal inflammation plays an important pathogenic role in diabetic retinopathy (DR). Microglial activation is a key step in retinal inflammation in DR. The molecular mechanism for the microglial activation in DR remains elusive. Peroxisome Proliferator-Activated Receptor α (PPARα) is a ligand-activated nuclear receptor and transcription factor. It is known to regulate lipid metabolism, and thus, PPARα agonists are used clinically to treat dyslipidemia. Two large, prospective clinical studies independently reported a surprising finding that oral administration of fenofibrate, a PPARα agonist, has robust therapeutic effects on DR in type 2 diabetic patients. However, fenofibrate has not been approved by US FDA for the treatment of DR, as many questions remain to be addressed. In the prior grant period, we have shown that PPARα levels are decreased in the retinas of diabetic patients and animal models, and that the therapeutic effect of fenofibrate on DR is through a PPARα-dependent mechanism. In addition, we have shown that PPARα global knockout (KO) exacerbated, while activation of PPARα by fenofibrate alleviated, retinal mitochondrial dysfunction in DR models. Our recent studies reported that PPARα KO alone induced activation of cGAS-STING signaling in retinal and circulating immune cells. Our preliminary studies showed that PPARα KO resulted in changed morphology and increased density and migration of microglial cells in the retina. To exclude possible secondary effects of PPARα global KO and define the function of PPARα in microglia, we have recently generated microglia-specific PPARα conditional KO (PPARαMCKO) and PPARα transgenic (PPARαMCTG) mice. We found that PPARα ablation in microglia alone increases the density and migration of microglia, and results in ERG decline, astrocyte senescence and retinal pericyte loss in diabetes. Therefore, we hypothesize that diabetes-induced down- regulation of PPARα in microglia results in metabolic dysregulation and subsequently, microglial activation and inflammation, leading to dysfunction and paracrine senescence of vascular cells and astrocytes through inter- cellular communications in DR. To address this hypothesis, we will determine if PPARα inhibits microglial activation and retinal inflammation through regulation of microglial metabolism and mitochondrial function in diabetes. We will compare microglial cell activation and polarization, metabolic profile, mitochondrial integrity in diabetic PPARαMCKO and PPARαMCTG mice and controls. We will determine the role of fatty acid transporter carnitine palmitoyltransferase 1a and fatty acid-binding protein 3 in the regulation of microglial metabolism by PPARα. We will also investigate how PPARα deficiency in microglia impairs retinal astrocytes and vascular cells through a disturbed metabolic coupling. We will measure retinal function and structure, vascular permeability and pericyte density in diabetic PPARαMCKO, PPARαMCTG and controls.... ## Key facts - **NIH application ID:** 10880119 - **Project number:** 2R01EY019309-14A1 - **Recipient organization:** WAKE FOREST UNIVERSITY HEALTH SCIENCES - **Principal Investigator:** Jian-Xing Jay Ma - **Activity code:** R01 (R01, R21, SBIR, etc.) - **Funding institute:** NIH - **Fiscal year:** 2024 - **Award amount:** $474,114 - **Award type:** 2 - **Project period:** 2009-03-01 → 2028-06-30 ## Primary source NIH RePORTER: https://reporter.nih.gov/project-details/10880119 ## Citation > US National Institutes of Health, RePORTER application 10880119, A new pathogenic mechanism for diabetic retinopathy (2R01EY019309-14A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10880119. Licensed CC0. --- *[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*