Combustion-derived air pollution is an environmental toxicant which is a global health concern due to rapid urbanization. Air pollution contains mixtures of pro-inflammatory stimulants such as fine and ultrafine particulate matter (PM&lt;2.5), gases (e.g., CO and NOx), and metals (e.g., Mn). Inhalation of these constituents are linked to damage within the lungs and peripheral circulatory system which implicates damage to the central nervous system. In particular, air pollution is linked to neurodegeneration through microglial activation which induces neuroinflammatory effects in the surrounding environment of the brain. This study examines the utility of an in vitro model after aerosol exposure to combustion products, specifically diesel particulate matter (DPM) on alveolar macrophages (U937). The collected post-exposure serum is then used to induce activation of microglial cells (HMC3). Endpoint analyses in alveolar macrophages included the analyses of MCP-1, IL6, and TNF-α expression. Endpoint analyses of microglial cells included the analyses of HLA-DR and CD14 expression. Lipopolysaccharides (10ng/mL) was used as a positive control to stimulate activation of microglial cells. Once activation was confirmed, cells were tested for ROS generation and neurotoxic cytokine expression. Our results show that the microglial cells, through a feedback loop with surrounding neurons, release neurotoxic pro-inflammatory markers of IL-1β, IL-6, TNF-α and CD86 and cause damage to neurons. High expression of ROS was also observed via spectroscopy and micrscopy. In conclusion, the data collected shows string evidence of activated microglial cells releasing inflammatory markers which implicates an indirect pathway of exposure (through lungs) to the brain as a method of inducing neuroinflammation and possibly neuronal cellular damage.

Exposure to combustion-derived air pollution may induce prolonged neuroinflammation

ACS Fall 2021

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.