Investigating the Effects of Short-Term E-Cigarette Exposure on Small Intestine Histology and Immunolocalization of Inflammatory Response Proteins in the House Mouse, Mus musculus

It is well-documented that vaping is a public health concern as more studies link e-cigarette usage to adverse health outcomes. This study investigated the impact of short-term e-cigarette use on the digestive tract of the house mouse, Mus musculus. Murine small intestinal regions (duodenum, jejunum, and ileum) were analyzed histologically following exposure to fumes of tropical rainbow blast-flavored e-cigarettes made by Elf Bar. Additionally, proteins involved in the inflammatory response (angiotensin-converting enzyme 2 (ACE-2), interleukin 6 (IL-6), and occludin) were localized using immunohistochemistry (IHC). ACE-2, a transmembrane receptor, catalyzed the production of anti-inflammatory proteins. IL-6 mediates systemic inflammatory responses. Occludin, a protein found in tight junctions in the small intestine, functions in the maintenance of the structural integrity of the lining of the digestive tract. IHC uses an antibody cascade to visualize specific proteins using an enzyme-substrate reaction. The substrate, diaminobenzide (DAB) chromogen, causes a color change as a result of an oxidation reaction indicating the presence of the target protein. A semi-quantitative analysis protocol was used to determine the effects of vaping on the relative abundance and localization of the proteins. Data collected from this study can be used to contribute to the growing body of evidence showing the detriment of e-cigarette use.