# Biomass Smoke Exposure Reduces DNA Methylation Levels in PRSS23 (cg23771366) in Women with Chronic Obstructive Pulmonary Disease

## TL;DR

Chronic exposure to biomass smoke is linked to reduced DNA methylation in the PRSS23 gene, which may contribute to COPD development in women.

## Contribution

This study identifies a specific DNA methylation site in PRSS23 associated with biomass smoke exposure and COPD.

## Key findings

- HW had 100% methylation at cg23771366, while COPD-BBS and BBES showed significantly lower levels.
- COPD-BBS had the lowest methylation levels at cg23771366 compared to BBES.
- Reduced methylation at PRSS23 is linked to chronic biomass smoke exposure and COPD.

## Abstract

COPD induced by biomass-burning smoke is a public health problem in developing countries. Biomass-based fuels are ineffective and deliver elevated levels of carbon monoxide, polycyclic aromatic hydrocarbons, and fine particulate matter. PRSS23 participates in extracellular matrix remodeling processes in COPD patients. Our objective was to estimate the DNA methylation levels of cg23771366 (PRSS23) and their clinical relevance in COPD caused by chronic exposure to biomass-burning smoke (BBS). We included 80 women with COPD (COPD-BBS) (≥200 h per year), 180 women with exposure to BBS (≥200 h per year) but without COPD (BBES), and 79 lung-healthy women (HW) without exposure to biomass-burning smoke. The DNA methylation analysis shows significant differences between the three groups included in this study (p < 0.001). HW had high methylation levels (100%) in cg23771366 (PRSS23). In comparison, COPD-BBS and BBES had low levels [0.91% vs. 9.17%, respectively], showing statistically significant differences (p = 0.011) between both groups, with the COPD-BBS presenting the lowest levels in the methylation of cg23771366. In conclusion, chronic biomass-burning smoke exposure is associated with decreased levels of DNA methylation at the CpG cg23771366 site in PRSS23, reinforcing the relationship between PRSS23 and particulate matter.