Enhanced Lung Inflammatory Response in Whole-body Compared to Nose-only Cigarette Smoke-exposed Mice

Abstract

Background: Chronic Obstructive Pulmonary Disease (COPD) is characterized by a progressive and abnormal inflammatory response in the lungs, mainly caused by cigarette smoking. Animal models exposed to cigarette smoke (CS) are used to mimic human COPD but the use of different CS protocols makes it difficult to compare the immunological and structural consequences of using a nose-only or whole-body CS exposure system. We hypothesized that when using a standardized CS exposure protocol based on particle density and CO (carbon monoxide) levels, the whole-body CS exposure system would generate a more severe inflammatory response than the nose-only system, due to possible sensitization, uptake of gases through the skin or uptake of tar particles stuck on the skin via grooming. Methods: In this study focusing on early COPD, mice were exposed twice daily 5 days a week to CS either with a nose-only or whole-body exposure system for 14 weeks to assess lung remodeling and inflammation. Data was analyzed with a one-way ANOVA with Bonferroni post-hoc test or Kruskal-Wallis with Dunn’s test for multiple comparison depending on respectively parametric or non-parametric datasets.Results: Both CS exposure systems induced a similar degree of lung function impairment and morphological alterations. Interestingly, an enhanced lymphoid presence in the bronchoalveolar lavage and lymph nodes with a higher mRNA expression of interleukin 6 and keratinocyte chemoattractant in the lungs were found with the whole-body system. Conclusion: Our data indicate that the inflammatory outcomes are more severe in the whole-body CS exposure compared to the nose-only system, but lung remodeling and lung function impairment are similarly affected. These observations can assist researchers to make an appropriate choice between the two CS exposure systems in designing their future studies in early drug interventions.

Caspase 9b Drives Cellular Transformation, Lung Inflammation, and Lung Tumorigenesis

“…Lung inflammation of C9b mice was semiquantitatively graded [Score 0-3 as 0 (none) and 3 (severe)] on the basis of the number and the size of peribronchial/bronchiolar/alveolar lymphoid aggregates and diffuse infiltrates observed on hematoxylin and eosin (H&E) images at 10x magnification blinded to the genotypes as described in (18). The alveolar area was calculated by morphometric analyses of trichrome stained images using ImageJ (NIH).…”

An e-cigarette aerosol generation, animal exposure and toxicants quantification system to characterizein vivonicotine kinetics in arterial and venous blood

“…Specifically, there are two types of exposure chambers: whole-body and nose-only [18][19][20][21] . The nose-only system delivers aerosols primarily to the nasal regions, similar to human vaping situations; however, it requires the animal to be tightly restrained in a holding tube and only suitable for short duration exposures.…”

“…It is possible that the animals inhale e-cig aerosols of different size and concentrations in nose-only and whole-body exposure settings, even the aerosols were generated in the same way. Multiple in vivo studies directly compared the nose-only and whole-body exposure of c-cig aerosols 19 or metal PMs 18 , but not e-cig aerosols. E-cig health studies typically employ chronic exposure strategy and measure the toxicant levels (e.g.…”