Differentially DNA methylation changes induced in vitro by traffic-derived nanoparticulate matter

Area of Science:

• Environmental Health
• Toxicology
• Epigenetics

Background:

• Diesel exhaust particulate matter (PM) is a widespread environmental pollutant.
• Nanoparticulate matter (nPM) poses significant health risks due to its small size and large surface area.
• Understanding the cellular and molecular mechanisms of nPM toxicity is crucial for public health.

Purpose of the Study:

• To investigate the in vitro cytotoxic effects of diesel exhaust nPM on human umbilical vein endothelial cells (HUVECs).
• To explore the epigenetics-wide DNA methylation changes induced by nPM exposure.
• To identify potential links between nPM exposure and cardiovascular diseases, specifically cardiomyopathy.

Main Methods:

• Exposure of HUVECs to varying concentrations of diesel exhaust nPM (SRM2975).
• Assessment of cytotoxicity, apoptosis, reactive oxygen species (ROS) generation, and DNA damage.
• Epigenetics-wide DNA methylation profiling using an Illumina 850K beadchip.
• Gene Ontology (GO) and Kyoto Encyclopaedia of Genes and Genomes (KEGG) pathway analyses.

Main Results:

• Low nPM concentrations (≤10 μg/mL) induced apoptosis, DNA damage, and increased ROS levels.
• High nPM concentration (20 μg/mL) significantly decreased HUVEC viability.
• 149 differentially methylated probes were identified, with 86.6% showing hypermethylation.
• Enriched GO terms and KEGG pathways were associated with calcium ion regulation and cardiomyopathy.

Conclusions:

• Traffic-derived nPM exhibits significant cytotoxicity and induces cellular damage in HUVECs.
• nPM exposure is associated with differential DNA methylation patterns, particularly hypermethylation.
• These epigenetic changes and cellular effects suggest a robust association between nPM and cardiomyopathy.