Pro-inflammatory effects of road wear particles and diesel exhaust particles in bronchial epithelial cells and macrophages

Area of Science:

• Environmental Health Sciences
• Toxicology
• Cell Biology

Background:

• Comparative data on traffic-derived particulate matter (PM) from combustion versus non-exhaust sources is limited.
• Understanding the differential health impacts of various PM sources is crucial for public health.
• Non-exhaust PM, such as tire and road wear particles (TRWP), are increasingly recognized as significant air pollutants.

Purpose of the Study:

• To compare the inflammatory potential of TRWP and diesel exhaust particles (DEP) in human bronchial epithelial cells (HBEC3-KT) and THP-1-derived macrophages.
• To investigate the role of the aryl hydrocarbon receptor (AhR) in mediating particle-induced inflammatory responses.
• To assess the combined effects of TRWP and DEP exposure on cellular inflammation.

Main Methods:

• Exposure of HBEC3-KT and THP-1-derived macrophages to TRWP and DEP.
• Measurement of cytokine release (CXCL8, IL-1α, IL-1β, TNFα) and gene expression (inflammation, xenobiotic metabolism, redox response markers).
• Utilized the AhR inhibitor CH223191 to elucidate receptor involvement in cellular responses.

Main Results:

• Both TRWP and DEP induced pro-inflammatory responses in both cell types.
• TRWP demonstrated pro-inflammatory responses of similar or greater magnitude compared to DEP.
• Combined exposure to TRWP and DEP resulted in enhanced pro-inflammatory responses.

Conclusions:

• TRWP and DEP induce inflammation through distinct mechanisms in human bronchial epithelial and macrophage-like cells.
• TRWP represent a significant health hazard due to their comparable inflammatory potential to DEP.
• The synergistic effect of combined TRWP and DEP exposure highlights the complex interplay of PM components in driving adverse health outcomes.