# Nutrient coordination of pancreatic vasculature and B-cells

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2020 · $531,537

## Abstract

PROJECT SUMMARY
The most common etiology of intrauterine growth restriction (IUGR) is placental insufficiency and decreased
fetal nutrient supply. In order to survive, the fetus adapts in ways which promote the most efficient use of a
limited energy supply. Pancreatic β-cells are key in this adaptation. The β-cell secretes insulin, which
stimulates fetal growth, in a nutrient regulated fashion. In IUGR insulin secretion is impaired. The adaptations
resulting in decreased insulin secretion include lower β-cell mass and impaired pancreatic islet development. If
these adaptations persist into adulthood they can contribute to the higher risk of type 2 diabetes mellitus in
previously IUGR adults. New evidence is emerging which shows the importance of the islet endothelial cell
(EC) for normal adult insulin secretion. Consistent with human IUGR, we show decreased pancreatic
vascularity in a sheep placental insufficiency model of IUGR. We also have identified impaired cross talk
between the islet EC and β-cell. Both EC produced hepatocyte growth factor (HGF) and β-cell produced
vascular endothelial growth factor A (VEGFA) are decreased. Importantly, though, our novel preliminary data
show that increasing the amino acid supply in IUGR fetal sheep restores fetal insulin secretion and increases
β-cell mass and islet size with a proportional increase in islet vascularity. Therefore, the long term goal of this
proposal is to test the hypothesis that reduced fetal amino acid supply is responsible for impaired fetal
pancreatic vascularity, β-cell mass, islet size, and insulin secretion in IUGR and that this is mediated by
inhibition of islet HGF and VEGFA production. In Aim 1 we will use isolated fetal sheep islets and islet ECs to
determine the capacity for VEGFA to stimulate islet EC HGF production and for HGF to stimulate β-cell
VEGFA production. This will demonstrate a novel islet feed forward HGF-VEGFA signaling loop which can
coordinate islet growth with vascular supply. Furthermore, we will show that this signaling can be increased in
IUGR islets when stimulated with the appropriate growth factors. In Aim 2 we will test the hypothesis that the
islet EC is a novel nutrient sensor producing HGF in response to increased amino acids, and that the EC
nutrient sensor is responsive to increased amino acids in PI-IUGR. In aim 3 we will test the hypothesis that
chronically decreased amino acid supply to the PI-IUGR fetus is primarily responsible for impaired islet HGF-
VEGFA signaling. Following fetal infusions of various amino acid mixtures we will measure in vivo fetal insulin
secretion, islet size and vascularity, β-cell mass, and isolated islet and islet EC signaling and function. This
proposal will show that the coordination of fetal islet growth and vascular supply is key in the pathogenesis of
impaired islet development and insulin secretion in IUGR. Furthermore, we will show that this process is
amenable to manipulation with amino acids in a way that wil...

## Key facts

- **NIH application ID:** 9964764
- **Project number:** 5R01DK088139-10
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Paul Joseph Rozance
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2020
- **Award amount:** $531,537
- **Award type:** 5
- **Project period:** 2011-09-15 → 2022-06-30

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/9964764

## Citation

> US National Institutes of Health, RePORTER application 9964764, Nutrient coordination of pancreatic vasculature and B-cells (5R01DK088139-10). Retrieved via AI Analytics 2026-05-26 from https://api.ai-analytics.org/grant/nih/9964764. Licensed CC0.

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