# Role of Hyperglycemia/Hyperinsulinemia in the Breakdown of the Blood Retinal Barrier in Diabetic Retinopathy

> **NIH NIH F31** · CLEVELAND CLINIC LERNER COM-CWRU · 2024 · $48,974

## Abstract

Abstract
Diabetic retinopathy (DR) is a leading cause of preventable blindness in developed countries. Breakdown of the
blood retinal barrier (BRB) in DR leads to macular edema and is one of the earliest events during the
development of disease. The blood retinal barrier is comprised of inner and outer components: the outer barrier
is formed by tight junctions between the retinal pigment epithelial (RPE) cells, and the inner barrier is formed by
tight junctions between the retinal vascular endothelial cells. While the inner blood retinal barrier has been well
studied, the development and regulation of the outer blood retinal barrier has not been carefully examined in the
context of DR. Tight junction protein, Claudin-19, is the predominant claudin in the RPE, and has been shown to
play a role in the barrier properties of the RPE. Additionally, previous work from our laboratory suggest that
hyperinsulinemia (as seen in type 2 diabetes) may lead to disruption of the outer BRB. The purpose of this study
is to identify the spatial localization and functions of claudins in the RPE and test the hypothesis that regulation
of RPE claudins with hyperglycemia/hyperinsulinemia leads to breakdown of the blood retinal barrier.
Understanding the molecular mechanisms involved in breakdown of the outer blood retinal barrier will help
identify therapeutic targets for macular edema in diabetic retinopathy.

## Key facts

- **NIH application ID:** 10823543
- **Project number:** 1F31EY035125-01A1
- **Recipient organization:** CLEVELAND CLINIC LERNER COM-CWRU
- **Principal Investigator:** Karen Hernandez
- **Activity code:** F31 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $48,974
- **Award type:** 1
- **Project period:** 2024-03-01 → 2027-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10823543

## Citation

> US National Institutes of Health, RePORTER application 10823543, Role of Hyperglycemia/Hyperinsulinemia in the Breakdown of the Blood Retinal Barrier in Diabetic Retinopathy (1F31EY035125-01A1). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10823543. Licensed CC0.

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