# Role of macrophages and miRNA in regulating lung macrophage polarization and lung pathogenesis during respiratory virus-induced acute lung injury in normal and diabetic Syrian hamsters.

> **NIH VA I01** · BOISE VA MEDICAL CENTER · 2024 · —

## Abstract

Over 25% of US Veterans have diabetes, and those Veterans are at an increased risk of hospitalization
and increased morbidity/mortality following severe respiratory viral infections, such as, influenza (H1N1), SARS-
CoV-2 (COVID) and adenovirus (Ad). Infection with these respiratory viruses causes acute lung injury (ALI) that
can result in acute respiratory distress syndrome (ARDS), with a mortality rate of ~40%. There are few
therapeutic options for ALI/ARDS. Virus induced ALI/ARDS is driven primarily by uncontrolled inflammatory
responses. Alveolar macrophages both induce and resolve ALI/ARDS, based on their polarization/inflammatory
state. The plasticity of macrophages to vary between pro-inflammatory (M1, pro-ALI/ARDS) and anti-
inflammatory (M2, anti-ALI/ARDS) phenotypes is driven by their metabolic states. Diabetes is a metabolic
disorder in which levels of blood glucose are high and glycolysis is the preferred cellular metabolic pathway.
Macrophages from diabetic patients have a high rate of glycolysis and an increased M1 phenotype. In addition,
macrophages from diabetic patients have a lower rate of plasticity to change from M1 to M2 because of this shift
to glycolysis. One possibility is that this glycolytic shift contributes to severe outcomes from respiratory viral
infections in diabetic patients.
 The Syrian hamster is naturally permissive for influenza, SARS-CoV-2 and Ad (in contrast to other
rodents that require viral adaptation). In addition, the Syrian hamster can naturally become diabetic with a high
fat/high sugar diet. Ad14p1 is an emergent strain of Ad14 that has caused outbreaks of severe respiratory illness
and ALI/ARDS throughout the world. Hamster infection with Ad14p1 results in a patchy bronchopneumonia, as
seen in other severe human viral respiratory infections. In contrast, the prototype strain of Ad14 induces little
lung inflammation. Other studies have shown that cells dying from Ad14 infection induce an M2-like human
macrophage response, while cells dying from Ad14p1 infection fail to change M1 alveolar macrophages to an
M2 phenotype. This dying infected cell activity is regulated by the expression of the Ad gene, E1B 20K. Cells
infected by Ad14 produced sufficient E1B 20K to repolarize M1 macrophages to M2, while Ad14p1 infection does
not produce sufficient E1B 20K, and the infected cells fail to alter M1 macrophage polarization. Therefore, the
hamster model of Ad14p1 ALI/ARDS provides an appropriate system to study how diabetes affects macrophage
polarization and pathogenesis during severe viral respiratory infections. The long-term goal of this project is to
understand how emergent viruses regulate macrophage polarization to develop novel therapeutic strategies to
drive macrophage polarization to an ALI/ARDS resolving phenotype in both diabetic and non-diabetic Veterans.
 To achieve this goal, a multi-omics approach will be used to identify and phenotype macrophages in
normal and diabetic hamsters infected with A...

## Key facts

- **NIH application ID:** 10901901
- **Project number:** 5I01BX006273-02
- **Recipient organization:** BOISE VA MEDICAL CENTER
- **Principal Investigator:** Jay R Radke
- **Activity code:** I01 (R01, R21, SBIR, etc.)
- **Funding institute:** VA
- **Fiscal year:** 2024
- **Award amount:** —
- **Award type:** 5
- **Project period:** 2023-08-01 → 2027-07-31

## Primary source

NIH RePORTER: https://reporter.nih.gov/project-details/10901901

## Citation

> US National Institutes of Health, RePORTER application 10901901, Role of macrophages and miRNA in regulating lung macrophage polarization and lung pathogenesis during respiratory virus-induced acute lung injury in normal and diabetic Syrian hamsters. (5I01BX006273-02). Retrieved via AI Analytics 2026-05-23 from https://api.ai-analytics.org/grant/nih/10901901. Licensed CC0.

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