Biology subjects

Aguiar, J. A.

Publications and source records attributed to Aguiar, J. A..

6 recordsLinked to original sources

bioRxiv2020

Potentiation of Long-Acting β2-Agonist and Glucocorticoid Responses in Human Airway Epithelial Cells by Modulation of Intracellular cAMP

IntroductionOver 300 million people in the world live with asthma, resulting in 500,000 annual global deaths with future increases expected. It is estimated that around 50-80% of asthma exacerbations are due to viral infections. Currently, a combination of long-acting beta agonists (LABA) for bronchodilation and glucocorticoids (GCS) to control lung inflammation represent the dominant strategy for the management of asthma, however it is still sub-optimal in 35-50% of moderate-severe asthmatics resulting in persistent lung inflammation, impairment of lung function, and risk of mortality. Mechanistically, LABA/GCS combination therapy results in synergistic efficacy mediated by intracellular cyclic adenosine monophosphate (cAMP). HypothesisIncreasing intracellular cAMP during LABA/GCS combination therapy via inhibiting phosphodiesterase 4 (PDE4) and/or blocking export of cAMP by ATP Binding Cassette Transporter C4 (ABCC4), will potentiate anti-inflammatory responses of mainstay LABA/GCS therapy. MethodsExpression and localization experiments were performed using in situ hybridization and immunohistochemistry in human lung tissue from healthy subjects, while confirmatory transcript and protein expression analyses were performed in primary human airway epithelial cells and cell lines. Intervention experiments were performed on the human airway epithelial cell line, HBEC-6KT, by pre-treatment with combinations of LABA/GCS with PDE4 and/or ABCC4 inhibitors followed by Poly I:C or imiquimod challenge as a model for viral stimuli. Cytokine readouts for IL-6, IL-8, CXCL10/IP-10, and CCL5/RANTES were quantified by ELISA. ResultsUsing archived human lung and human airway epithelial cells, ABCC4 gene and protein expression were confirmed in vitro and in situ. LABA/GCS attenuation of Poly I:C or imiquimod-induced IL-6 and IL-8 was potentiated with ABCC4 and PDE4 inhibition, which was greater when ABCC4 and PDE4 inhibition was combined. Modulation of cAMP levels had no impact on LABA/GCS modulation of Poly I:C-induced CXCL10/IP-10 or CCL5/RANTES. ConclusionModulation of intracellular cAMP levels by PDE4 or ABCC4 inhibition is able to potentiate LABA/GCS efficacy in human airway epithelial cells challenged with viral stimuli. The data suggests further exploration of the value of adding cAMP modulators to mainstay LABA/GCS therapy in asthma for potentiated anti-inflammatory efficacy.

immunology↗

bioRxiv2020

Gene expression and in situ protein profiling of candidate SARS-CoV-2 receptors in human airway epithelial cells and lung tissue

In December 2019, SARS-CoV-2 emerged causing the COVID-19 pandemic. SARS-CoV, the agent responsible for the 2003 SARS outbreak, utilizes ACE2 and TMPRSS2 host molecules for viral entry. ACE2 and TMPRSS2 have recently been implicated in SARS-CoV-2 viral infection. Additional host molecules including ADAM17, cathepsin L, CD147, and GRP78 may also function as receptors for SARS-CoV-2. To determine the expression and in situ localization of candidate SARS-CoV-2 receptors in the respiratory mucosa, we analyzed gene expression datasets from airway epithelial cells of 515 healthy subjects, gene promoter activity analysis using the FANTOM5 dataset containing 120 distinct sample types, single cell RNA sequencing (scRNAseq) of 10 healthy subjects, immunoblots on multiple airway epithelial cell types, and immunohistochemistry on 98 human lung samples. We demonstrate absent to low ACE2 promoter activity in a variety of lung epithelial cell samples and low ACE2 gene expression in both microarray and scRNAseq datasets of epithelial cell populations. Consistent with gene expression, rare ACE2 protein expression was observed in the airway epithelium and alveoli of human lung. We present confirmatory evidence for the presence of TMPRSS2, CD147, and GRP78 protein in vitro in airway epithelial cells and confirm broad in situ protein expression of CD147 in the respiratory mucosa. Collectively, our data suggest the presence of a mechanism dynamically regulating ACE2 expression in human lung, perhaps in periods of SARS-CoV-2 infection, and also suggest that alternate receptors for SARS-CoV-2 exist to facilitate initial host cell infection.

immunology↗

bioRxiv2020

Expression of the endocannabinoid system in the human airway epithelial cells: Impact of sex and chronic respiratory disease status

Recreational and medicinal cannabis consumption in the past 12 months has been reported in 1/5th of Canadians, with greater use in males relative to females. Cannabis smoking is the dominant route of delivery in consumers, with the airway epithelium functioning as the site of first contact for inhaled phytocannabinoids. The endocannabinoid system is responsible for mediating the physiological effects of inhaled phytocannabinoids. Acute cannabis smoke inhalation can result in bronchodilation, which may have applications in chronic respiratory disease management. In contrast, chronic cannabis smoke inhalation is associated with reduced lung function and bronchitis, which challenges potential applications in the lung. The contribution of the endocannabinoid system in the airway epithelium to either beneficial or harmful physiological responses remains to be clearly defined in males and females and those with underlying chronic respiratory disease. To begin to address this knowledge gap, a curated dataset of 1090 unique human bronchial brushing gene expression profiles was created from Gene Expression Omnibus deposited microarray datasets. The dataset included 616 healthy subjects, 136 subjects with asthma, and 338 subjects with COPD. A 27-gene endocannabinoid signature was analyzed across all samples with sex and disease specific-analyses performed. Immunohistochemistry and immunoblots were performed to confirm in situ and in vitro protein expression of select genes in human airway epithelial cells. We confirm three receptors for cannabinoids, CB1, CB2, and TRPV1, are expressed at the protein level in human airway epithelial cells in situ and in vitro, justifying examining the downstream endocannabinoid pathway more extensively at the gene expression level. Sex status was associated with differential expression of 6/27 genes. In contrast, disease status was associated with differential expression of 18/27 genes in asthmatics and 22/27 genes in COPD subjects. We confirm at the protein level that TRPV1, the most differentially expressed candidate in our analyses, was up-regulated in airway epithelial cells from asthmatics relative to healthy subjects. Our data demonstrate that endocannabinoid system is expressed in human airway epithelial cells with expression impacted by disease status and minimally by sex. The data suggest that cannabis consumers may have differential physiological responses in the respiratory mucosa, which could impact both acute and chronic effects of cannabis smoke inhalation.

cell biology↗

bioRxiv2020

ABCF1 regulates dsDNA-induced immune responses in human airway epithelial cells

BackgroundThe airway epithelium represents a critical component of the human lung that helps orchestrate defences against respiratory tract viral infections, which are responsible for more than 2.5 million deaths/year globally. Innate immune activities of the airway epithelium rely Toll-like receptors (TLRs), nucleotide binding and leucine-rich-repeat pyrin domain containing (NLRP) receptors, and cytosolic nucleic acid sensors. ATP Binding Cassette (ABC) transporters are ubiquitous across all three domains of life - Archaea, Bacteria, and Eukarya - and expressed in the human airway epithelium. ABCF1, a unique ABC family member that lacks a transmembrane domain, has been defined as a cytosolic nucleic acid sensor that regulates CXCL10, interferon-{beta} expression, and downstream type I interferon responses. We tested the hypothesis that ABCF1 functions as a dsDNA nucleic acid sensor in human airway epithelial cells important in regulating antiviral responses. MethodsExpression and localization experiments were performed using in situ hybridization and immunohistochemistry in human lung tissue from healthy subjects, while confirmatory transcript and protein expression was performed in human airway epithelial cells. Functional experiments were performed with siRNA methods in human airway epithelial cells. Complementary transcriptomic analyses were performed to explore the contributions of ABCF1 to gene expression patterns. ResultsUsing archived human lung and human airway epithelial cells, we confirm expression of ABCF1 gene and protein expression in these tissue samples, with a role for mediating CXCL10 production in response to dsDNA viral mimic challenge. Although, ABCF1 knockdown was associated with an attenuation of select genes involved in the antiviral responses, Gene Ontology analyses revealed a greater interaction of ABCF1 with TLR signaling suggesting a multifactorial role for ABCF1 in innate immunity in human airway epithelial cells. ConclusionABCF1 is a candidate cytosolic nucleic acid sensor and modulator of TLR signaling that is expressed at gene and protein levels in human airway epithelial cells. The precise level where ABCF1 protein functions to modulate immune responses to pathogens remains to be determined but is anticipated to involve IRF-3 and CXCL10 production.

immunology↗

bioRxiv2019

A comparative analysis of cannabis and tobacco smoke exposure on human airway epithelial cell gene expression, immune phenotype, and response to formoterol and budesonide treatment

Global recreational cannabis use is a potentially important public health issue that would benefit from experimental evidence to inform policy, regulations, and individual user practices. Comparative analyses between cannabis and tobacco smoke, the latter long reported to have negative impacts on respiratory health, may help provide context and provide clinically relevant evidence.\n\nTo address this unmet need we performed a comparative study between cannabis and tobacco smoke exposure in the Calu-3 human airway epithelial cells using concentration-response and pharmacological intervention study designs with outcome measurements of cell viability, epithelial cell barrier function, cytokine profile, and transcriptomics.\n\nOur results demonstrate that cannabis smoke exposure reduces epithelial cell barrier function without impacting cell viability, accompanied by a cytokine profile associated with inflammation (elevated IL-6 and IL-8), barrier repair (elevated TGF- and PDGF-AA) and suppressed antiviral immunity (decreased IP-10 and RANTES). Transcriptomic analyses revealed a cannabis smoke induced signature associated with suppressed antiviral genes and induction of oncogenic and oxidative stress pathways. Similar trends were observed for tobacco smoke exposure. A formoterol/budesonide intervention was unable to prevent cannabis smoke-induced reductions in antiviral pathways or normalize induction of oncogenic and oxidative stress responses.\n\nOur results show striking similarities between cannabis and tobacco smoke exposure on impairing barrier function, suppressing antiviral pathways, potentiating of pro-inflammatory mediators, and inducing oncogenic and oxidative stress gene expression signatures. Furthermore, we demonstrate that an intervention with formoterol and budesonide is unable to completely normalized cannabisinduced responses. Collectively our data suggest that cannabis smoke exposure is not innocuous and may possess many of the deleterious properties of tobacco smoke, warranting additional studies to support public policy, government regulations, and individual user practices.

bioinformatics↗

bioRxiv2018

The impact of cigarette smoke exposure, and COPD or asthma status on ABC transporter gene expression in human airway epithelial cells

RationaleThe respiratory mucosa coordinates responses to infections, allergens, and exposures to air pollution. A relatively unexplored aspect of the respiratory mucosa are the expression and function of ATP Binding Cassette (ABC) transporters. ABC transporters are conserved in prokaryotes and eukaryotes, with humans expressing 48 transporters divided into 7 classes (ABCA, ABCB, ABCC, ABCD, ABDE, ABCF, and ABCG). Throughout the human body, ABC transporters regulate cAMP levels, chloride secretion, lipid transport, and anti-oxidant responses. A deeper exploration of the expression patterns of ABC transporters in the respiratory mucosa is warranted to determine their relevance in lung health and disease.\n\nMethodsWe used a bioinformatic approach complemented with in vitro experimental methods for validation of candidate ABC transporters. We analyzed the expression profiles of all 48 human ABC transporters in the respiratory mucosa using bronchial epithelial cell gene expression datasets available in NCBI GEO from well-characterized patient populations of healthy subjects and individuals that smoke cigarettes, or have been diagnosed with COPD or asthma. The Calu-3 airway epithelial cell line was used to interrogate selected results using a cigarette smoke extract exposure model.\n\nResultsUsing 9 distinct gene-expression datasets of primary human airway epithelial cells, we completed a focused analysis on 48 ABC transporters in samples from healthy subjects and individuals that smoke cigarettes, or have been diagnosed with COPD or asthma. In situ gene expression data demonstrate that ABC transporters are i) variably expressed in epithelial cells from different airway generations (top three expression levels - ABCA5, ABCA13, and ABCC5), ii) regulated by cigarette smoke exposure (ABCA13, ABCB6, ABCC1, and ABCC3), and iii) differentially expressed in individuals with COPD and asthma (ABCA13, ABCC1, ABCC2, ABCC9). An in vitro cell culture model of cigarette smoke exposure was able to recapitulate the in situ changes observed in cigarette smokers for ABCA13 and ABCC1.\n\nConclusionsOur in situ human gene expression data analysis reveals that ABC transporters are expressed throughout the airway generations in airway epithelial cells and can be modulated by environmental exposures important in chronic respiratory disease (e.g. cigarette smoking) and in individuals with chronic lung diseases (e.g. COPD or asthma). Our work highlights select ABC transporter candidates of interest and a relevant in vitro model that will enable a deeper understanding of the contribution of ABC transporters in the respiratory mucosa in lung health and disease.

bioinformatics↗