Transcriptomic changes in the nasal epithelium associated with diesel engine exhaust exposure

Area of Science:

• Environmental Health
• Molecular Biology
• Toxicology

Background:

• Diesel engine exhaust (DEE) is a known lung carcinogen, but its precise molecular mechanisms remain unclear.
• Understanding the cellular and molecular impact of DEE exposure is crucial for public health and occupational safety.

Purpose of the Study:

• To investigate transcriptomic alterations in the nasal epithelium of factory workers exposed to DEE.
• To identify molecular pathways affected by occupational DEE exposure and their relationship with smoking status.

Main Methods:

• Nasal epithelial brushings were collected from DEE-exposed and unexposed factory workers.
• Gene expression profiling was performed using microarrays, followed by linear modeling to identify DEE-associated genes.
• Pathway enrichment analysis (EnrichR) and Gene Set Enrichment Analysis (GSEA) were employed to interpret gene expression data.

Main Results:

• 225 genes showed expression changes associated with DEE exposure, enriched in pathways like oxidative stress response and cell cycle (MAPK/ERK).
• The DEE gene signature overlapped with genes upregulated by cigarette smoking and alterations seen in acute DEE exposure studies.
• A clear exposure-response relationship was observed between elemental carbon levels and the DEE gene expression signature.

Conclusions:

• A distinct gene expression signature associated with occupational DEE exposure was identified in nasal epithelium.
• This signature demonstrates an exposure-dependent pattern and shares similarities with the molecular effects of smoking and acute DEE exposure.
• This study provides novel insights into the molecular consequences of significant DEE exposure in an occupational setting.