# Blood outer retina barrier regulation

> **NIH NIH R01** · UNIVERSITY OF LOUISVILLE · 2021 · $576,278

## Abstract

Project Summary/Abstract
Mutations in rod photoreceptor-specific genes in retinitis pigmentosa (RP) cause diminished
peripherial and night-time vision. But, it is secondary loss of cone function, leading to
diminished high-resolution daylight vision utilized for reading, facial recognition and other daily
tasks that is most debilitating. Events leading to loss of cone function in RP are still being
unraveled. Like other neurons, photoreceptors depend upon glucose, which they use for
energy as well as ongoing synthesis to replace visual pigment-rich membraneous outer
segments (OS) as they undergo daily light-induced phagocytosis. The RPE serves as a
blood-outer retinal barrier transporting glucose and nutrients from the choroid circulation
to adjacent photoreceptors. We provide evidence that glucose transport from the RPE to
photoreceptors for new OS synthesis is linked to OS phagocytosis. As abundant mutant
rod OS are lost and phagocytosis diminishes in RP, glucose transport becomes short-
circuited leading to cone starvation. We will examine the signaling pathway regulating
glucose transport from the RPE and linked metabolome/epigenome changes in these
cells during RP progression in both mice and pigs, a large animal model of RP where
cones are concentrated into a visual streak.

## Key facts

- **NIH application ID:** 10093049
- **Project number:** 5R01EY030933-02
- **Recipient organization:** UNIVERSITY OF LOUISVILLE
- **Principal Investigator:** DOUGLAS Chase DEAN
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $576,278
- **Award type:** 5
- **Project period:** 2020-02-01 → 2025-01-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10093049

## Citation

> US National Institutes of Health, RePORTER application 10093049, Blood outer retina barrier regulation (5R01EY030933-02). Retrieved via AI Analytics 2026-05-22 from https://api.ai-analytics.org/grant/nih/10093049. Licensed CC0.

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