Transcriptomic responses in the blood and sputum of cigarette smokers compared to e-cigarette vapers.

Introduction:
This article presents a study that aimed to identify transcriptomic differences in the blood and sputum of e-cigarette users compared to conventional cigarette smokers and healthy controls. The study also describes the biological pathways affected by these tobacco products.

Key Points:

* The study enrolled 65 participants, including 8 smokers, 9 e-cigarette users, and 4 controls.
* Blood and sputum samples were collected, and RNa was extracted and processed for RNa sequencing.
* Differential gene expression analysis was performed using the Likelihood Ratio Test (LRT) and pairwise comparisons.
* Weighted gene co-network analysis (WGCNa) identified gene module associations, and Ingenuity Pathway analysis (IPa) identified canonical pathways associated with tobacco products.
* In blood, there were 16 differentially expressed genes (DEGs) in a three-group comparison, with 7 DEGs between e-cigarette users and controls, 35 DEGs between smokers and controls, and 13 DEGs between smokers and e-cigarette users.
* In sputum, there were 438 DEGs in the three-group comparison, with 2 DEGs between e-cigarette users and controls, 270 DEGs between smokers and controls, and 468 DEGs between smokers and e-cigarette users.
* Most gene modules identified through WGCNa associated with tobacco product exposures also were associated with cotinine and exhaled CO levels.
* IPa showed more canonical pathways altered by conventional cigarette smoking than by e-cigarette use.

Main Message:
The study found that cigarette smoking and e-cigarette use led to transcriptomic changes in both blood and sputum. however, conventional cigarettes induced much stronger transcriptomic responses in both compartments. These findings suggest that e-cigarettes may not be entirely harmless and may still have potential health risks. Further studies are needed to better understand the long-term effects of e-cigarette use on human health.

Perez MF, Yurieva M, Poddutoori S, Mortensen EM, Crotty alexander LE, Williams a. Transcriptomic responses in the blood and sputum of cigarette smokers compared to e-cigarette vapers. Respiratory research. 2023;24(1):134. doi:10.1186/s12931-023-02438-x