A Heated tobacco product ‘IQOS’ exposure enhances apoptosis and emphysema in mice lungs

To assess the mechanism which caused emphysema in the IQOS group, we performed microarray analysis using homogenate lung tissue that were exposed to fresh air, IQOS aerosol, or cigarette smoke for 6 months. In microarray-based analysis, gene expressions to the air group were different in the IQOS and CS group, and apoptosis-related pathways were enhanced in the IQOS group. Apoptosis-related protein (cytochrome c, cleaved caspase-3, and cleaved PARP1) expression in the IQOS group were higher than air group in homogenete lungs. More single-stranded DNA and TUNEL positive alveolar cells were found in the IQOS group than control significantly. Twelve-week-old C57BL6/J male mice were divided into 3 groups; air-exposed, IQOS aerosol-exposed, and CS-exposed group, and exposed for 6 months. Microarray analysis and pathway analysis using whole lung specimens were performed to determine gene-expression profiles.