Electronic and regular cigarettes induce transcriptional and physiological changes in cardiomyocytes

Cigarette smoking is an important etiology for cardiac diseases and electronic cigarettes are increasing in popularity. In the current study, we assessed physiological and transcriptional changes in human induced pluripotent stem cell derived cardiomyocytes (iPS-CMs) after exposure to electronic cigarette extract (ECE) and conventional cigarette extract (CSE).

iPS-CMS were plated on multi-electrode array plates (MEA), electrical and contractile properties were determined by Maestro Edge and computer assisted video analysis (MuscleMotion). Transcriptional profiles were accessed by direct digital mRNA detection of heart failure targeted genes.

Both ECE and CSE extracts significantly prolong beat period from baseline compared to control after 2 days of exposure (0.74 ± 0.14 s for ECE and 0.78 ± 0.02 s for CSE). Prolonged time to peak in ECE and CSE were also significantly prolonged compared to control with a P < 0.05 (487 ± 44, 373 ± 21 and 312 ± 8 ms respectively). In addition, both ECE and CSE decrease cardiomyocyte contractility in a similar fashion. ECE exposed cells have 25 genes in discovery and 33 genes in validation experiments that were significantly different compared to control with P < 0.05. CSE exposed cells, however, do produce more profound effects on transcriptional profiles of heart failure with 53 genes in discovery and 40 genes in validation compared to control group with P < 0.05. In summary, both ECE and CSE are sufficiently toxic to impair cardiac physiology and alter myocyte gene expression. Transcriptional profiles of heart failure related genes are consistent with cigarettes altering expression of sarcomeric proteins and calcium handling.

Human cardiomyocytes can be utilized to study the molecular biology and toxicology of electronic and conventional cigarettes.