Biology subjects

Bratcher, P. E.

Publications and source records attributed to Bratcher, P. E..

3 recordsLinked to original sources

bioRxiv2022

Acute Vaping of a golden Syrian Hamster is Feasible and Leads to Nicotine-Dependent Respiratory Tract Inflammation

IntroductionE-cigarette vaping has become a major portion of nicotine consumption, especially for children and young adults. Although it is branded as a safer alternative to cigarette smoking, murine and rat models of sub-acute and chronic e-cigarette vaping exposure have shown many pro-inflammatory changes in the respiratory tract. An acute vaping exposure paradigm has not been demonstrated in the golden Syrian hamster, and the hamster is a readily available small animal model that has the unique benefit of becoming infected with and transmitting SARS-CoV-2 without genetic alteration to the animal or virus. MethodsUsing a two-day, whole-body vaping exposure protocol in male golden Syrian hamsters, we evaluated serum cotinine, bronchoalveolar lavage cells, lung and nasal histopathology, and gene expression in the nasopharynx and lung through RT-qPCR. Depending on the presence of nonnormality or outliers, statistical analysis was performed by ANOVA or Kruskal-Wallis tests. For tests that were statistically significant (p-value <0.05), post-hoc Tukey-Kramer and Dunns tests, respectively, were performed to make pairwise comparisons between groups. ResultsIn nasal tissue, RT-qPCR analysis revealed nicotine-dependent increases in genes associated with type 1 inflammation (CCL-5 and CXCL-10), fibrosis (TGF-{beta}), and a nicotine-independent decrease in the vasculogenesis/angiogenesis gene VEGF-A. In the lung, nicotine-dependent increases in the expression of genes involved in the renin-angiotensin pathway (ACE, ACE2), coagulation (tissue factor, Serpine-1), extracellular matrix remodeling (MMP-2, MMP-9), type 1 inflammation (IL-1{beta}, TNF-, and CXCL-10), fibrosis (TGF-{beta} and Serpine-1), oxidative stress response (SOD-2), neutrophil extracellular traps release (ELANE), and vasculogenesis and angiogenesis (VEGF-A) were identified. ConclusionTo our knowledge, this is the first demonstration that the Syrian hamster is a viable model of e-cig induced inhalational injury. In addition, this is the first report that e-cig vaping with nicotine can increase tissue factor gene expression in the lung. Our results show that even an acute exposure to e-cigarette vaping causes significant upregulation in the respiratory tract of pathways involving the renin-angiotensin system, coagulation, extracellular matrix remodeling, type 1 inflammation, fibrosis, oxidative stress response, NETosis, vasculogenesis, and angiogenesis.

pharmacology and toxicology↗

bioRxiv2022

IL-13-programmed airway tuft cells produce PGE2, which promotes CFTR-dependent mucociliary function

Chronic type 2 (T2) inflammatory diseases of the respiratory tract are characterized by mucus overproduction and disordered mucociliary function, which are largely attributed to the effects of IL-13 on common epithelial cell types (mucus secretory and ciliated cells). The role of rare cells in airway T2 inflammation is less clear, though tuft cells have been shown to be critical in the initiation of T2 immunity in the intestine. Using bulk and single cell RNA sequencing of airway epithelium and mouse modeling, we find that IL-13 expands and programs airway tuft cells towards eicosanoid metabolism, and that tuft cell deficiency leads to a reduction in airway prostaglandin E2 (PGE2) concentration. Allergic airway epithelia bear a signature of prostaglandin E2 activation, and PGE2 activation leads to CFTR-dependent ion and fluid secretion and accelerated mucociliary transport. Together these data reveal a role for tuft cells in regulating epithelial mucociliary function in the allergic airway.

immunology↗

bioRxiv2017

Phenotyping ciliary dynamics and coordination in response to CFTR-modulators in Cystic Fibrosis respiratory epithelial cells

The diagnosis and treatment of respiratory disorders are challenging and would benefit from new approaches to systematically assess ciliary beating dynamics and to test new drugs. A novel approach based on multiscale differential dynamic microscopy (multi-DDM) is shown to quantitatively assess collective beating of cilia in a non-biased automated manner, in human airway epithelial cells (HAECs) derived from subjects with cystic fibrosis (CF) and grown in 2D air-liquid interface culture. Multi-DDM can readily detect changes in both ciliary beat frequency (CBF) and cilia coordination that result from perturbations to the mucosal layer. The efficacy of three CFTR-modulating treatments is investigated: ivacaftor (VX-770) with lumacaftor (VX-809), VX-809 alone and Thymosin alpha 1 (T1) alone. All three treatments restore coordination of cilia beating in the CF cells, albeit to varying degrees. We argue cilia are affected by these treatments through the physical properties of the mucus. Phenotyping cilia dynamics through multi-DDM provides novel insight into the response of ciliary beating following treatment with drugs, and has application in the broader context of respiratory disease and for drug screening.\n\nOne sentence summaryA semi-automated and unbiased assay based on multiscale differential dynamic microscopy (multi-DDM) detects changes in the coordination and frequency of ciliary beating in F508del/F508del primary human airway cells under different conditions and in response to CFTR-modulating compounds.

physiology↗