# Mitochondrial oxidative stress: a target for treatment of doxorubicin-associated vascular endothelial dysfunction

> **NIH NIH F32** · UNIVERSITY OF COLORADO · 2021 · $24,105

## Abstract

PROJECT SUMMARY/ABSTRACT
The purpose of this F32 application is to support Dr. Zachary Clayton, a promising first-year postdoctoral
fellow in the laboratory of Dr. Douglas Seals, to conduct original research and scientific training that will
prepare him to become an independent, extramurally-funded investigator in the field of translational
cardiovascular physiology aimed at the prevention of cardiovascular diseases (CVD). Dr. Clayton will learn a
variety of new technical, conceptual and professional skills, including focused training in translational
preclinical vascular physiology research in mice. His proposed research project seeks to (Aim 1) investigate
the mechanism(s) by which doxorubicin (DOXO), the most commonly used anthracycline-chemotherapy
drug, mediates vascular endothelial dysfunction, a key pathophysiological step in the development of CVD.
He also will determine (Aim 2) if a translational mitochondrial-targeted antioxidant therapy, Mitoquinol
Mesylate (MitoQ®), can restore vascular endothelial dysfunction caused by DOXO in: a) young adult mice
soon after treatment; and b) middle-aged mice (treated with DOXO in adolescence) to “model” effects on
middle-aged DOXO-treated childhood cancer survivors. Endothelial dysfunction is typically mediated by
reduced bioavailability of the endothelium-derived dilator molecule, nitric oxide (NO), as a result of excessive
production of superoxide, which reacts with NO. Dysfunctional mitochondria are a major source of overall
superoxide production, due in part to inadequate compensatory increases in antioxidant defenses. DOXO has
been reported to decrease vascular endothelial function, but the underlying mechanisms and potential
therapeutic strategies are currently unknown. Guided by strong preliminary data, Dr. Clayton will investigate
the mechanism(s) by which DOXO mediates endothelial dysfunction, using ex vivo “pharmaco-dissection”
techniques, specifically focusing on the role of mitochondrial superoxide in decreasing NO bioavailability (Aim
1). Furthermore, Dr. Clayton will seek to establish initial (preclinical) proof-in-concept evidence that oral
supplementation of a mitochondrial-specific antioxidant, MitoQ, can mitigate DOXO-induced endothelial
dysfunction (Aim 2). Overall the proposed research has the potential to address 2 important strategic
research priorities of NHLBI: 1) determine the best strategy for reducing vascular morbidity and mortality in
childhood cancer survivors who are at enhanced risk of vascular events; 2) identifying therapeutic targets,
establishing proof of concept, and developing data for investigational new drug applications to enable early
translation of research findings to clinical applications. The sponsor, Dr. Seals, is an internationally recognized
and NIH funded scientist with a strong history of successful mentoring in translational biomedical research.
With his guidance, and the guidance of consulting mentors Drs. Anthony Donato, Michael Murphy and Judith...

## Key facts

- **NIH application ID:** 10403420
- **Project number:** 5F32HL151022-02
- **Recipient organization:** UNIVERSITY OF COLORADO
- **Principal Investigator:** Zachary S. Clayton
- **Activity code:** F32 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $24,105
- **Award type:** 5
- **Project period:** 2020-03-09 → 2021-07-08

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10403420

## Citation

> US National Institutes of Health, RePORTER application 10403420, Mitochondrial oxidative stress: a target for treatment of doxorubicin-associated vascular endothelial dysfunction (5F32HL151022-02). Retrieved via AI Analytics 2026-05-25 from https://api.ai-analytics.org/grant/nih/10403420. Licensed CC0.

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