Long-term e-cigarette aerosol exposure causes pulmonary emphysema in adult female and male mice.

Introduction:
This study aimed to evaluate long-term exposure to conventional cigarette smoke (CC) and electronic cigarette (EC) aerosol in adult male and female C57BL/6 mice. The study design included a 60-day exposure period followed by a 60-day cessation period. The study found that both CC and EC caused pulmonary emphysema in both male and female mice, with females appearing to be more susceptible to the deleterious effects of EC.

Key Points:

* The study used 48 C57BL/6 mice, divided into three groups (control, CC, and EC) with 8 mice per group for each sex.
* The mice were exposed to CC or EC for 60 days, followed by a 60-day cessation period.
* The study found that both CC and EC caused an influx of inflammatory cells to the lung in both males and females.
* Both CC and EC increased lipid peroxidation and protein oxidation in both males and females.
* IL-6 levels were increased in males and females exposed to EC, while IL-13 levels were higher in females exposed to both CC and EC.
* Both sexes exposed to EC and CC showed tissue damage characterized by septal destruction and increased alveolar spaces compared to control.
* Females exposed to EC showed a more significant increase in MMP-2 and MMP-9 activity compared to males.
* The study suggests that females may be more susceptible to the deleterious effects of EC compared to males.

Main Message:
The study demonstrates that long-term exposure to both CC and EC can cause pulmonary emphysema in both male and female mice, with females appearing to be more susceptible to the deleterious effects of EC. The study highlights the importance of considering sex differences in the assessment of the health effects of EC and the need for further research to investigate the mechanisms of this possible susceptibility.

Rodriguez-herrera aJ, de Souza aBF, Castro T de F, et al. Long-term e-cigarette aerosol exposure causes pulmonary emphysema in adult female and male mice. Regulatory toxicology and pharmacology : RTP. 2023;142:105412. doi:10.1016/j.yrtph.2023.105412