# Targeting endothelial cell metabolism to improve recovery from acute ischemic stroke in older mice.

> **NIH NIH R21** · UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH · 2024 · $399,345

## Abstract

Here we interrogate a novel therapeutic strategy for improving outcomes of acute ischemic stroke (AIS) in
older mice. We will test whether amplifying endothelial cell (EC) autophagy, EC glucose transporter 1 (GLUT1),
and/or PKC/PKD signaling serve as viable approaches for improving outcomes of this debilitating condition.
AIS deprives cerebral artery ECs of nutrients which decreases mechanistic target of rapamycin complex 1
(mTORC1) activity and stimulates autophagic flux to support basal metabolism. We reported that aging
represses autophagic flux in ECs from mice and humans. We hypothesize that the age-associated impairment
of EC autophagy worsens AIS outcomes for three main reasons. First, if autophagy is stalled, damaged
organelles will accumulate and contribute to cellular toxicity. Second, autophagic flux avails the cell of
macromolecules generated from protein/organelle recycling that can be used for ATP production, and
impairments would lead to more pronounced energy deficiency. Third, EC autophagy elicits an important
metabolic reprogramming of cells that is critical for arterial vasodilation, which impacts blood and oxygen
delivery. We hypothesize that restoring EC autophagy in older mice improves AIS outcomes.
Several pieces of data support this contention. First, we found that mTORC1 inhibition increases whole-body
autophagy and improves outcomes of AIS. Conversely, inhibiting autophagy specifically in ECs worsens
outcomes of AIS. Underscoring the importance of EC autophagy, mice with EC specific depletion of autophagy
were refractory to benefits of whole-body autophagy upregulation. In Aim 1 (i) we will rejuvenate age-
associated reductions in EC autophagy via AAV-mediated delivery of ATG3 directly to ECs.
We find that EC autophagy compromise lowers glucose transporter 1 (GLUT1) expression. Mechanistically, the
aging-associated decline in EC autophagy and EC GLUT1 blunts EC glycolytic flux and ATP production,
diminishing subsequent ATP/ADP-mediated purinergic 2Y1 receptor (P2Y1R) activation of endothelial nitric
oxide synthase. As such, EC GLUT1 is a tractable site for intervention downstream of defective EC autophagy.
In Aim 1 (ii) we predict that loss of EC GLUT1 worsens AIS outcomes in adult mice, whereas AAV-mediated
delivery of GLUT1 directly to ECs mitigates AIS outcomes in older mice [Aim 1 (iii)].
We reported that PKC/PKD activation provides the signaling link between the P2Y1R and endothelial nitric
oxide synthase. In autophagy and GLUT1 deficient ECs and arteries, function of both tissues can be re-
established by PKC/PKD activation using bryostatin-1. In Aim 2 we hypothesize that repurposing this approved
drug rejuvenates signaling to endothelial nitric oxide synthase to improve AIS outcomes in older mice.
Results from our studies could hasten development of therapeutics targeting EC metabolism to improve
cerebrovascular health and combat the debilitating complications of AIS in older persons.

## Key facts

- **NIH application ID:** 10811525
- **Project number:** 1R21AG081780-01A1
- **Recipient organization:** UTAH STATE HIGHER EDUCATION SYSTEM--UNIVERSITY OF UTAH
- **Principal Investigator:** Robert A Campbell
- **Activity code:** R21 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2024
- **Award amount:** $399,345
- **Award type:** 1
- **Project period:** 2024-09-23 → 2026-08-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10811525

## Citation

> US National Institutes of Health, RePORTER application 10811525, Targeting endothelial cell metabolism to improve recovery from acute ischemic stroke in older mice. (1R21AG081780-01A1). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10811525. Licensed CC0.

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