Macrophage Metabolite Reduces Airway Inflammation and Fibrosis Through Iron Transfer

Chronic inflammation and tissue scarring are major drivers of aging and disease, making this discovery of a natural anti-inflammatory pathway particularly significant for longevity research. Scientists have identified how immune cells use their own metabolism to fight inflammation and prevent harmful scarring.

Researchers studied benign airway stenosis, a condition involving inflammation and scarring of breathing passages. Using advanced multi-omics analysis of human and mouse tissue samples, they focused on the ACOD1-itaconate metabolic pathway in macrophages, key immune cells that orchestrate inflammatory responses.

The team used genetic knockout models, cell culture experiments, and tracked the transfer of proteins between different cell types. They tested both natural itaconate and a synthetic derivative called 4-octyl itaconate (4-OI) to understand the mechanism.

Key findings showed that itaconate activates the NRF2 pathway, boosting production of FTH1, an iron-storage protein that reduces oxidative stress. Most remarkably, macrophages package FTH1 into exosomes and transfer it to fibroblasts, cells responsible for scar formation. This transfer triggers controlled cell death in overactive fibroblasts, preventing excessive scarring while resolving inflammation.

For longevity and health optimization, this research suggests that supporting macrophage metabolism and the NRF2 pathway could help maintain healthy inflammatory responses throughout aging. The itaconate pathway represents a natural mechanism for resolving inflammation without suppressing immune function entirely. This could inform strategies for preventing age-related chronic inflammation while maintaining protective immunity, potentially extending healthspan and reducing inflammatory disease risk.