Altered expression of DNA Methyltransferases in biomass using rural women in West Bengal

Abstract

Unprocessed solid biomass such as wood, coal, dung and agricultural residues are still used in many rural households in India as main source of domestic energy for cooking, boiling water and heating. Combustion of biomass releases a considerable amount of particulate matters (PM) and toxic pollutants. Therefore, use of biomass as fuels causes very high level of indoor air pollution (IAP) in rural households and the women who do most of the daily household cooking with these fuels, receive the maximum exposure. Thus, the cells of the nasopharynx, oral cavity, airways and the lungs in these women get severely affected and undergo harmful changes. The present study is conducted to appraise the effects of IAP generated PMs and/or carcinogens on epigenetic changes in airway epithelial cells as little information is known about it. In the present study LPG using rural women were used as controls against biomass using rural women and both these groups comprise of non-smokers and non-chewer of tobacco and betel nut. Significantly enhanced production of ROS was evident in biomass fuel users with depletion of SOD, a major scavenger enzyme in comparison to LPG using control women. Furthermore, Immunocytochemical evaluation showed significantly increased expressions of DNMT1 and DNMT3a enzymes and reduced expression of SET7, an inhibitor of DNMT1, in airway epithelial cells of biomass-using rural women in comparison to LPG using control women. The findings indicate major epigenetic changes in airway epithelial cells of biomass users due to long-term exposure to particulate pollution which also increases the risk of lung cancer in these women.