Total particulate matter concentration skews cigarette smoke's gene expression profile

Area of Science:

• Pulmonary Medicine
• Toxicology
• Genomics

Background:

• Animal models are crucial for studying chronic obstructive pulmonary disease (COPD) pathogenesis.
• Existing cigarette smoke exposure protocols and systems vary significantly, complicating comparisons.
• The comparability of different animal models to human COPD gene expression profiles is unclear.

Purpose of the Study:

• To compare gene expression profiles from various mouse models of cigarette smoke exposure.
• To relate findings from animal models to human clinical cohorts.
• To assess the suitability of different animal models for mimicking human COPD gene expression.

Main Methods:

• Analysis of six public murine gene expression datasets from different cigarette smoke exposure systems.
• Construction of a 55-gene network with 17 clusters from 234 differentially regulated genes.
• Comparison of the gene network's regulation in three human COPD cohorts.

Main Results:

• Gene expression patterns varied with total particulate matter concentration in mice, with higher concentrations activating immune/inflammatory responses.
• Significant differences in gene regulation were observed across human cohorts, independent of pack-year.
• No single animal model perfectly mirrored any human cohort, but some showed greater resemblance.

Conclusions:

• Different cigarette smoke exposure systems elicit distinct gene expression responses in animal models.
• The relevance of animal models to human COPD can vary, necessitating careful selection and validation.
• Specific exposure systems may better recapitulate observed gene expression changes in particular human COPD cohorts.