Up-regulation of ACE2, the SARS-CoV-2 receptor, in asthmatics on maintenance inhaled corticosteroids

Proline is increased in allergic asthma and promotes airway remodeling

Proline and its synthesis enzyme pyrroline-5-carboxylate reductase 1 (PYCR1) are implicated in epithelial-mesenchymal transition (EMT), yet how proline and PYCR1 function in allergic asthmatic airway remodeling via EMT has not yet been addressed to our knowledge. In the present study, increased levels of plasma proline and PYCR1 were observed in patients with asthma. Similarly, proline and PYCR1 in lung tissues were high in a murine allergic asthma model induced by house dust mites (HDMs). Pycr1 knockout decreased proline in lung tissues, with reduced airway remodeling and EMT. Mechanistically, loss of Pycr1 restrained HDM-induced EMT by modulating mitochondrial fission, metabolic reprogramming, and the AKT/mTORC1 and WNT3a/β-catenin signaling pathways in airway epithelial cells. Therapeutic inhibition of PYCR1 in wild-type mice disrupted HDM-induced airway inflammation and remodeling. Deprivation of exogenous proline relieved HDM-induced airway remodeling to some extent. Collectively, this study illuminates that proline and PYCR1 involved with airway remodeling in allergic asthma could be viable targets for asthma treatment.

Characteristics and outcomes of adult patients with asthma presenting with COVID-19: A comparative cohort study

BACKGROUND

Bronchial asthma affects about 20% of Qatar's population. The impact of asthma on COVID-19 outcomes is controversial. The aim of this study was to explore the impact of asthma on COVID-19 outcomes and the predictors of COVID-19-related morbidity and mortality in a cohort of asthma patients infected by COVID-19.

METHODS

This is a retrospective cohort study of adult patients with asthma infected with COVID-19, who were recruited from Hamad Medical Corporation (HMC), the main healthcare system in Qatar. Patients were matched to a control group of non-asthmatic COVID-19 patients (1:2) based on sex, age, and other comorbidities.

RESULTS

Between March and August 2020, 616 patients with asthma met the inclusion criteria. The need for hospitalization among patients with asthma was independently associated with older age (adjusted odds ratio [aOR] for 10 years, 1.32; 95% confidence interval [CI], 1.13-1.54; p = 0.001) and hypertension (aOR, 2.4; 95% CI, 1.43-3.93; p = 0.001) but not with the use of inhaled corticosteroids (ICS), long-acting beta2 agonists, montelukast, or tiotropium. Patients with asthma required less hospitalization for COVID-19 than non-asthmatic patients (28.2% vs. 37.3%, respectively; aOR, 0.59; 95% CI, 0.77-0.90; p < 0.001). However, admission to the intensive care unit (ICU) was comparable between both groups (3.3% vs. 2.2%; aOR, 1.64; 95% CI, 0.78-3.43; p = 0.193). No difference in mortality rate was observed between the two groups.

CONCLUSIONS

In Qatar, adult patients with asthma do not appear to be at higher risk of COVID-19-related hospitalization or ICU admission compared to the general adult COVID-19-infected population. Older age and hypertension were the only significant predictors of COVID-19-related hospitalization among patients with asthma. Further larger studies are required to confirm such an association.

High apoptotic endothelial microparticle levels measured in asthma with elevated IgE and eosinophils

While asthma is considered an inflammatory-mediated airway epithelial and smooth muscle disorder, there is increasing evidence of airway capillary endothelial dysfunction associated with vascular remodelling and angiogenesis in some individuals with this condition. The inflammation is typically characterized as type-2 high (eosinophilic) vs type 2-low (neutrophilic and pauci-granulocytic); we hypothesized that the type-2 high group would be more likely to evidence endothelial dysfunction. As a biomarker of these processes, we hypothesized that nonsmokers with allergic asthma may have elevated plasma levels of endothelial microparticles (EMPs), membrane vesicles that are shed when endothelial cells undergo activation or apoptosis. Total and apoptotic circulating EMPs were measured by fluorescence-activated cell analysis in patients with allergic asthma (n = 29) and control subjects (n = 26), all nonsmokers. When the entire group of patients with asthma were compared to the control subjects, there were no differences in total circulating EMPs nor apoptotic EMPs. However, patients with asthma with elevated levels of IgE and eosinophils had higher levels of apoptotic EMPs, compared to patients with asthma with mildly increased IgE and eosinophil levels. This observation is relevant to precision therapies for asthma and highlights the importance of sub-phenotyping in the condition.

Bioinformatic Analysis of Key Regulatory Genes in Adult Asthma and Prediction of Potential Drug Candidates

Asthma is a common chronic disease that is characterized by respiratory symptoms including cough, wheeze, shortness of breath, and chest tightness. The underlying mechanisms of this disease are not fully elucidated, so more research is needed to identify better therapeutic compounds and biomarkers to improve disease outcomes. In this present study, we used bioinformatics to analyze the gene expression of adult asthma in publicly available microarray datasets to identify putative therapeutic molecules for this disease. We first compared gene expression in healthy volunteers and adult asthma patients to obtain differentially expressed genes (DEGs) for further analysis. A final gene expression signature of 49 genes, including 34 upregulated and 15 downregulated genes, was obtained. Protein-protein interaction and hub analyses showed that 10 genes, including POSTN, CPA3, CCL26, SERPINB2, CLCA1, TPSAB1, TPSB2, MUC5B, BPIFA1, and CST1, may be hub genes. Then, the L1000CDS² search engine was used for drug repurposing studies. The top approved drug candidate predicted to reverse the asthma gene signature was lovastatin. Clustergram results showed that lovastatin may perturb MUC5B expression. Moreover, molecular docking, molecular dynamics simulation, and computational alanine scanning results supported the notion that lovastatin may interact with MUC5B via key residues such as Thr80, Thr91, Leu93, and Gln105. In summary, by analyzing gene expression signatures, hub genes, and therapeutic perturbation, we show that lovastatin is an approved drug candidate that may have potential for treating adult asthma.

The effect of the COVID-19 pandemic on pediatric asthma-related emergency department visits and hospital admissions in Montréal, Quebec: a retrospective cohort study

BACKGROUND

Asthma is a chronic respiratory condition that affects 10% of Canadian children and is often exacerbated by viral respiratory infections, prompting concerns about the severity of SARS-CoV-2 disease in children with asthma. We compared sociodemographic and clinical characteristics of children presenting to the emergency department and the incidence of these visits, before and during the pandemic.

METHODS

We included children aged 0 to 17 years presenting with asthma to 2 tertiary pediatric emergency departments in Montréal, Quebec, between the prepandemic (Jan. 1, 2017, to Mar. 31, 2020) and pandemic (Apr. 1, 2020, to June 30, 2021) periods. We compared the number of emergency department visits and hospital admissions with an interrupted time series analysis and compared the sociodemographic characteristics based on the Canadian Index of Multiple Deprivation (CIMD) and clinical characteristics (including triage level, intensive care admissions, etc.) with Mann-Whitney and χ² tests.

RESULTS

We examined 22 746 asthma-related emergency department visits. During the pandemic, a greater proportion of patients presented a triage level 1 or 2 (19.3% v. 14.7%) and were admitted to the intensive care unit (2.5% v. 1.3%). The patients' CIMD quintile distributions did not differ between the 2 periods. We found a 47% decrease (relative risk [RR] 0.53, 95% confidence interval [CI] 0.37 to 0.76) in emergency department visits and a 49% decrease (RR 0.51, 95% CI 0.34 to 0.76) in hospital admissions during the pandemic.

INTERPRETATION

The decrease in asthma-related emergency department visits was observed through the third wave of the pandemic, but children presented with a higher acuity and with no identified sociodemographic changes. Future studies are required to understand individual behaviours that may have led to the increased acuity at presentation observed in this study.

Insights into potential mechanisms of asthma patients with COVID-19: A study based on the gene expression profiling of bronchoalveolar lavage fluid

Background

The 2019 novel coronavirus disease (COVID-19), caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is currently a major challenge threatening the global healthcare system. Respiratory virus infection is the most common cause of asthma attacks, and thus COVID-19 may contribute to an increase in asthma exacerbations. However, the mechanisms of COVID-19/asthma comorbidity remain unclear.

Methods

The “Limma” package or “DESeq2” package was used to screen differentially expressed genes (DEGs). Alveolar lavage fluid datasets of COVID-19 and asthma were obtained from the GEO and GSV database. A series of analyses of common host factors for COVID-19 and asthma were conducted, including PPI network construction, module analysis, enrichment analysis, inference of the upstream pathway activity of host factors, tissue-specific analysis and drug candidate prediction. Finally, the key host factors were verified in the GSE152418 and GSE164805 datasets.

Results

192 overlapping host factors were obtained by analyzing the intersection of asthma and COVID-19. FN1, UBA52, EEF1A1, ITGB1, XPO1, NPM1, EGR1, EIF4E, SRSF1, CCR5, PXN, IRF8 and DDX5 as host factors were tightly connected in the PPI network. Module analysis identified five modules with different biological functions and pathways. According to the degree values ranking in the PPI network, EEF1A1, EGR1, UBA52, DDX5 and IRF8 were considered as the key cohost factors for COVID-19 and asthma. The H₂O₂, VEGF, IL-1 and Wnt signaling pathways had the strongest activities in the upstream pathways. Tissue-specific enrichment analysis revealed the different expression levels of the five critical host factors. LY294002, wortmannin, PD98059 and heparin might have great potential to evolve into therapeutic drugs for COVID-19 and asthma comorbidity. Finally, the validation dataset confirmed that the expression of five key host factors were statistically significant among COVID-19 groups with different severity and healthy control subjects.

Conclusions

This study constructed a network of common host factors between asthma and COVID-19 and predicted several drugs with therapeutic potential. Therefore, this study is likely to provide a reference for the management and treatment for COVID-19/asthma comorbidity.

The effect of allergy and asthma as a comorbidity on the susceptibility and outcomes of COVID-19

The coronavirus disease 2019 (COVID-19) pandemic causes an overwhelming number of hospitalization and deaths with a significant socioeconomic impact. The vast majority of studies indicate that asthma and allergic diseases do not represent a risk factor for COVID-19 susceptibility nor cause a more severe course of disease. This raises the opportunity to investigate the underlying mechanisms of the interaction between an allergic background and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. The majority of patients with asthma, atopic dermatitis, allergic rhinitis, chronic rhinosinusitis, food allergies and drug allergies exhibit an over-expression of type 2 immune and inflammatory pathways with the contribution of epithelial cells, innate lymphoid cells, dendritic cells, T cells, eosinophils, mast cells, basophils, and the type 2 cytokines interleukin (IL)-4, IL-5, IL-9, IL-13, and IL-31. The potential impact of type 2 inflammation-related allergic diseases on susceptibility to COVID-19 and severity of its course have been reported. In this review, the prevalence of asthma and other common allergic diseases in COVID-19 patients is addressed. Moreover, the impact of allergic and non-allergic asthma with different severity and control status, currently available asthma treatments such as inhaled and oral corticosteroids, short- and long-acting β2 agonists, leukotriene receptor antagonists and biologicals on the outcome of COVID-19 patients is reviewed. In addition, possible protective mechanisms of asthma and type 2 inflammation on COVID-19 infection, such as the expression of SARS-CoV-2 entry receptors, antiviral activity of eosinophils and cross-reactive T-cell epitopes, are discussed. Potential interactions of other allergic diseases with COVID-19 are postulated, including recommendations for their management.