# Capillary control of cerebral blood flow, and its disruption in small vessel disease

> **NIH NIH R01** · UNIVERSITY OF COLORADO DENVER · 2021 · $386,484

## Abstract

The survival of neurons in the brain depends on an uninterrupted, dynamically regulated supply of blood-
borne nutrients, which are delivered through a dense capillary network. Despite extensive study, the
mechanisms underlying the functional linkage between neuronal demand and vascular supply, termed
neurovascular coupling (NVC), remains poorly understood. Anatomically, intracerebral (parenchymal)
arterioles form bottlenecks that precisely control cerebral hemodynamics, and capillary endothelial cells are
ideally positioned to detect neuronal activity. We propose that prostaglandin E2 (PGE2), a suggested NVC
mediator, acts at the level of capillaries to initiate a Ca2+ wave that travels along endothelial cells to reach the
upstream arteriole, where it triggers vasodilation through endothelium-dependent hyperpolarization. Our
extensive preliminary data also describe a capillary signaling complex between the epidermal growth factor
receptor (EGFR) and transient receptor potential vanilloid 3 (TRPV3) channels that is involved in generating
this PGE2-induce retrograde Ca2+ signal. Using a well-established genetic mouse model of CADASIL, a
hereditary form of small vessel disease, we further propose that pathogenic mechanisms that result in EGFR
pathway inhibition in smooth muscle also depress EGFR/TRPV3 signaling complex in capillaries, resulting in
impaired NVC. To test these ideas, we engage a wide variety of novel, state-of-the-art experimental approaches
using intact animals, native tissue and freshly isolated cells, complemented by sophisticated computational
modeling. Aim 1 will explore how capillary PGE2 and TRPV3 signaling generates retrograde Ca signals to
2+
cause upstream arteriolar dilation, taking advantage of our newly developed pressurized arteriole-capillary ex
vivo preparation. Using extracellular matrix disruptions characteristic of CADASIL as a framework, Aim 2 will
provide the first insights into the mechanisms by which TRPV3 channels and evoked upstream dilation are
regulated by EGFR and its upstream regulators TIMP3, a matrix metalloproteinase inhibitor, and ADAM17, a
metalloproteinase that mediates shedding of the EGFR ligand, HB-EGF. Building on our previous report that
CADASIL causes voltage-gated K (KV) channel upregulation in arteriolar myocytes, Aim 3 will explore the
 +
hypothesis that increased KV current density limits arteriolar conducted dilation, and thus NVC, initiated by
capillary PGE2/TRPV3 signaling in CADASIL. The proposed work has the potential to revolutionize our
understanding of communication within the brain microcirculation, and as such should provide the foundation
for understanding small vessel diseases of the brain.

## Key facts

- **NIH application ID:** 10115093
- **Project number:** 5R01HL136636-06
- **Recipient organization:** UNIVERSITY OF COLORADO DENVER
- **Principal Investigator:** Fabrice Dabertrand
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $386,484
- **Award type:** 5
- **Project period:** 2017-02-01 → 2023-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10115093

## Citation

> US National Institutes of Health, RePORTER application 10115093, Capillary control of cerebral blood flow, and its disruption in small vessel disease (5R01HL136636-06). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10115093. Licensed CC0.

---

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