# Mechanisms regulating VEGF receptors in diabetic angiogenesis

> **NIH NIH R01** · BOSTON CHILDREN'S HOSPITAL · 2021 · $814,512

## Abstract

PROJECT SUMMARY/ABSTRACT
Diabetes affects over 30 million people in the United States and costs a staggering $327 billion a year in direct
medical costs and lost productivity. Diabetes adversely affects blood vessels as hyperglycemia and insulin
resistance are key players in the development of atherosclerosis, peripheral neuropathy, retinopathy, and
peripheral artery disease. Peripheral artery disease is a chronic condition where fatty deposits called plaques
build up in the arteries to the legs, resulting in ulcerations and infections, which precedes 85% of diabetes-
related amputations. Our goal is to understand how chronic hyperglycemia impairs vascular endothelial cell
function to identify molecular targets that will form the basis for new therapeutic approaches to treat ulcerations
and the other vascular complications of diabetes. Vascular endothelial growth factor receptors 2 and 3
(VEGFR2/3) are critical regulators of blood vessel growth or angiogenesis. These receptors are significantly
reduced in the vascular endothelium of diabetic patients, resulting in inadequate angiogenesis. In our
previously funded application, we showed that diabetic conditions induced expression of autophagosome
proteins and promoted degradation of VEGFR2/3. In particular, we identified the protein Unc-51-like autophagy
activating kinase 1 (Ulk1) as an important inhibitor of angiogenesis by stimulating autophagosome formation
causing selective degradation of VEGFR2/3. Loss of endothelial Ulk1 elevated VEGFR2/3 levels and
enhanced angiogenic responses such as endothelial cell proliferation, migration, and tube formation. In this
competing renewal application, we present compelling preliminary data demonstrating the Forkhead box O1
transcription factor (FoxO1) controls expression of endothelial Ulk1 in both in vivo and in vitro diabetic model
systems and that deficiency of endothelial FoxO1 inhibits autophagosome formation. We also show the
noncoding RNA miR183-3p inhibits endothelial FoxO1 expression and the deficiency of epsin 1 and 2 adaptor
proteins promotes FoxO1 ubiquitination and degradation in diabetes. These findings strongly suggest that
targeting FoxO1 to protect VEGFR2/3 from degradation may represent a novel therapeutic strategy to prevent
inadequate vascularization in diabetic ulcers. In view of that, we will investigate the following Specific Aims
using unique mutant mice as well as in vitro models of diabetes: 1) determine the molecular mechanisms
underlying FoxO1-mediated inhibition of neovascularization in diabetes, 2) determine the molecular
mechanisms regulating FoxO1 activity in the diabetic endothelium, and 3) determine the therapeutic potential
of targeting FoxO1 by genetic deletion or miR183-3p-mediated inhibition in diabetic angiogenesis. Our findings
will enhance understanding of the cellular mechanisms behind VEGFR2/3 loss and activation of FoxO1 in
regulating blood vessel damage in diabetes. We anticipate that therapies targeting FoxO1 m...

## Key facts

- **NIH application ID:** 10219890
- **Project number:** 5R01HL130845-06
- **Recipient organization:** BOSTON CHILDREN'S HOSPITAL
- **Principal Investigator:** Hong Chen
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $814,512
- **Award type:** 5
- **Project period:** 2016-01-01 → 2024-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10219890

## Citation

> US National Institutes of Health, RePORTER application 10219890, Mechanisms regulating VEGF receptors in diabetic angiogenesis (5R01HL130845-06). Retrieved via AI Analytics 2026-05-21 from https://api.ai-analytics.org/grant/nih/10219890. Licensed CC0.

---

*[NIH grants dataset](/datasets/nih-grants) · CC0 1.0*
