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Updated: Nov 4, 2025
Depletion and Reconstitution of Macrophages in Mice
Published on: August 1, 2012
Polystyrene microplastics induce an immunometabolic active state in macrophages
Seth D Merkley1, Harrison C Moss1, Samuel M Goodfellow1
1Division of Gastroenterology and Hepatology, Department of Internal Medicine, University of New Mexico School of Medicine, Albuquerque, NM, USA.
Abstract:
Anti-inflammatory and proinflammatory responses in macrophages are influenced by cellular metabolism. Macrophages are the primary phagocyte in mucosal environments (i.e., intestinal tract and lungs) acting as first-line defense against microorganisms and environmental pollutants. Given the extensive contamination of our food and water sources with microplastics, we aimed to examine the metabolic response in macrophages to microplastic particles (MPs). Utilizing murine macrophages, we assessed the metabolic response of macrophages after polystyrene MP phagocytosis. The phagocytosis of MP by macrophages induced a metabolic shift toward glycolysis and a reduction in mitochondrial respiration that was associated with an increase of cell surface markers CD80 and CD86 and cytokine gene expression associated with glycolysis. The gastrointestinal consequences of this metabolic switch in the context of an immune response remain uncertain, but the global rise of plastic pollution and MP ingestion potentially poses an unappreciated health risk. Macrophage phagocytosis of microplastics alters cellular metabolism. - Macrophages cannot degrade PS MP. - MP phagocytosis increases glycolysis in murine macrophages. - MP phagocytosis reduces mitochondrial respiration in murine macrophages.
Insights
Microplastic ingestion by macrophages alters cellular metabolism, increasing glycolysis and reducing mitochondrial respiration. This immune response to microplastics (MPs) may pose an unappreciated health risk due to plastic pollution.
Area of Science:
- Immunology
- Cellular Metabolism
- Environmental Health
Background:
- Macrophages are key immune cells in mucosal tissues, defending against pathogens and pollutants.
- Microplastic (MP) contamination is widespread in food and water sources.
- Cellular metabolism significantly influences macrophage inflammatory and anti-inflammatory responses.
Purpose of the Study:
- To investigate the metabolic alterations in macrophages following microplastic particle (MP) phagocytosis.
- To understand the impact of polystyrene MPs on macrophage cellular metabolism.
Main Methods:
- Murine macrophages were utilized to assess metabolic responses.
- Phagocytosis of polystyrene MPs was induced.
- Metabolic profiles, including glycolysis and mitochondrial respiration, were analyzed.
- Cell surface markers (CD80, CD86) and cytokine gene expression were evaluated.
Main Results:
- Macrophage phagocytosis of MPs induced a metabolic shift towards glycolysis.
- Mitochondrial respiration was reduced post-MP phagocytosis.
- Increased expression of CD80, CD86, and glycolysis-associated cytokines was observed.
Conclusions:
- Microplastic phagocytosis significantly alters macrophage cellular metabolism.
- Macrophages are unable to degrade polystyrene MPs.
- The metabolic reprogramming of macrophages by MPs may represent an emerging health concern.
