By

Alejandro López-Landa

Hector Romo-Parra

Air pollution has long been recognized for its detrimental effects on the respiratory and cardiovascular systems, but recent research has shed light on a lesser-known victim: the central nervous system (CNS). A new review by Rodriguez et al. explores how exposure to ozone (O₃), a common air pollutant, can trigger oxidative stress and inflammation in the brain, potentially contributing to neurodegenerative diseases such as Alzheimer’s and Parkinson’s.

Understanding Oxidative Stress and Inflammation

Ozone, a powerful oxidizing agent, can infiltrate the body through the lungs, initiating a cascade of reactions that lead to the production of reactive oxygen species (ROS) and reactive nitrogen species (RNS). These molecules disrupt cellular processes and overwhelm the body’s natural antioxidant defenses, resulting in oxidative stress. In the brain, this process is particularly harmful due to the CNS’s vulnerability, including its high content of polyunsaturated fatty acids and relatively low antioxidant capacity.

The Blood-Brain Barrier and Neuroinflammation

One critical finding highlighted by the study is the role of the blood-brain barrier (BBB). Prolonged exposure to ozone compromises the integrity of the BBB, allowing pro-inflammatory cytokines such as interleukin-6 (IL-6) and tumor necrosis factor-alpha (TNF-α) to infiltrate the brain. This leads to neuroinflammation, which can cause damage to neurons and glial cells, further accelerating neurodegenerative processes.

Molecular Pathways and Gene Expression

Rodriguez et al. discuss the activation of key molecular pathways, including the Nuclear Factor kappa B (NF-κB) and Mitogen-Activated Protein Kinase (MAPK) pathways, which regulate the expression of genes involved in inflammation, oxidative stress, and apoptosis. The review also highlights the upregulation of genes associated with oxidative stress response, such as those coding for heat shock proteins (HSPs) and antioxidant enzymes like superoxide dismutase (SOD).

Implications for Public Health

This research underscores the importance of addressing air pollution not only for respiratory health but also for its potential impact on the brain. The findings suggest that chronic exposure to ambient ozone could have significant public health implications, particularly in urban areas with high levels of pollution.

Conclusion

As we continue to grapple with the effects of air pollution, understanding its impact on the nervous system is crucial. Studies like the one conducted by Rodriguez et al. provide valuable insights into the mechanisms through which pollutants like ozone affect brain health, paving the way for new preventive and therapeutic strategies.

Reference

Rodriguez, P., López-Landa, A., Romo-Parra, H., Rubio-Osornio, M., & Rubio, C. (2024). Unraveling the ozone impact and oxidative stress on the nervous system. Toxicology, 509, 153973. doi:10.1016/j.tox.2024.153973