# Dietary DHA mitigates ozone induced pulmonary inflammation

> **NIH NIH R01** · OHIO STATE UNIVERSITY · 2021 · $559,247

## Abstract

PROJECT SUMMARY
Premise and hypothesis: Ozone (O3) is a criteria air pollutant that increases the incidence of chronic
pulmonary diseases. The detrimental health effects upon O3 exposure occur in part through pulmonary
inflammation initiated by alveolar macrophage production of cytokine/chemokines. O3-induced inflammation
in the alveolar macrophage is driven by toll-like receptor 4 (TLR4), that increases NFB activation and
subsequent production of proinflammatory cytokines. Therefore, targeting TLR4 driven signaling in
alveolar macrophages is a viable target to mitigate O3-induced pulmonary inflammation. In this
application, we focus on the role of diet in regulating alveolar macrophage TLR4-mediated
inflammatory responses upon O3 exposure. Specifically, dietary docosahexaenoic acid (DHA), an
omega-3 polyunsaturated fatty acid that is poorly consumed in the western diet, may protect against O3-
induced pulmonary inflammation. Based on strong preliminary data, we propose the central hypothesis
that DHA suppresses and resolves pulmonary inflammation through two distinct mechanisms: 1) Structurally,
we propose that DHA acyl chains of the plasma membrane remodel the size and composition of alveolar
macrophage lipid rafts to suppress downstream signaling and cytokine secretion; 2) Biochemically, DHA
undergoes enzymatic conversion into specialized pro-resolving lipid mediators (SPM), which are
highly potent immunoresolvants. As a consequence, DHA-derived SPMs decrease NFB activation
and the production of proinflammatory cyto/chemokines while promoting the clearance of apoptotic
cells termed ‘efferocytosis’. The hypothesis is supported by preliminary data to show that DHA
decreases murine O3 induced pulmonary inflammation, augments levels of SPMs while increasing
expression of the SPM receptor ALX/FPR2, and remodels lipid raft size in vitro. Approach: To
define the structural and biochemical mechanisms of DHA, we propose three aims. In Aim 1, we
will demonstrate that DHA improves O3-induced pulmonary inflammation and resolution of injury through
the use of DHA supplementation and a DHA-deficient mouse. In Aim 2, we will establish the mechanism
by which DHA remodels the biophysical structure of lipid rafts of alveolar macrophages to suppress
downstream signaling using cutting-edge quantitative imaging approaches. In Aim 3, we will establish
how DHA improves O3-induced pulmonary inflammation through the production of SPMs including the
use of an ALX/FPR knockout mouse. The proposed aims will innovatively merge inhalation
toxicology, nutritional biochemistry, membrane biophysics, and immunology. Impact:
Completion of this proposal will: 1) provide the scientific rationale for clinical DHA supplementation
studies mitigating O3-induced morbidity and; 2) provide key mechanistic links between
environmental pollutant exposure and diet that will inform targeted therapeutic strategies. Collectively, this
application is of high priority given that it sets the ba...

## Key facts

- **NIH application ID:** 10168536
- **Project number:** 5R01ES031378-02
- **Recipient organization:** OHIO STATE UNIVERSITY
- **Principal Investigator:** Kymberly Mae Gowdy
- **Activity code:** R01 (R01, R21, SBIR, etc.)
- **Funding institute:** NIH
- **Fiscal year:** 2021
- **Award amount:** $559,247
- **Award type:** 5
- **Project period:** 2020-05-20 → 2025-02-28

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10168536

## Citation

> US National Institutes of Health, RePORTER application 10168536, Dietary DHA mitigates ozone induced pulmonary inflammation (5R01ES031378-02). Retrieved via AI Analytics 2026-05-24 from https://api.ai-analytics.org/grant/nih/10168536. Licensed CC0.

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