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1.
Sultan Qaboos Univ Med J ; 22(2): 163-166, 2022 May.
Article in English | MEDLINE | ID: covidwho-1876288
3.
BMJ Open Respir Res ; 9(1)2022 May.
Article in English | MEDLINE | ID: covidwho-1854368

ABSTRACT

BACKGROUND: Patients often report persistent symptoms beyond the acute infectious phase of COVID-19. Hyperpolarised 129Xe MRI provides a way to directly measure airway functional abnormalities; the clinical relevance of 129Xe MRI ventilation defects in ever-hospitalised and never-hospitalised patients who had COVID-19 has not been ascertained. It remains unclear if persistent symptoms beyond the infectious phase are related to small airways disease and ventilation heterogeneity. Hence, we measured 129Xe MRI ventilation defects, pulmonary function and symptoms in ever-hospitalised and never-hospitalised patients who had COVID-19 with persistent symptoms consistent with post-acute COVID-19 syndrome (PACS). METHODS: Consenting participants with a confirmed diagnosis of PACS completed 129Xe MRI, CT, spirometry, multi-breath inert-gas washout, 6-minute walk test, St. George's Respiratory Questionnaire (SGRQ), modified Medical Research Council (mMRC) dyspnoea scale, modified Borg scale and International Physical Activity Questionnaire. Consenting ever-COVID volunteers completed 129Xe MRI and pulmonary function tests only. RESULTS: Seventy-six post-COVID and nine never-COVID participants were evaluated. Ventilation defect per cent (VDP) was abnormal and significantly greater in ever-COVID as compared with never-COVID participants (p<0.001) and significantly greater in ever-hospitalised compared with never-hospitalised participants who had COVID-19 (p=0.048), in whom diffusing capacity of the lung for carbon-monoxide (p=0.009) and 6-minute walk distance (6MWD) (p=0.005) were also significantly different. 129Xe MRI VDP was also related to the 6MWD (p=0.02) and post-exertional SpO2 (p=0.002). Participants with abnormal VDP (≥4.3%) had significantly worse 6MWD (p=0.003) and post-exertional SpO2 (p=0.03). CONCLUSION: 129Xe MRI VDP was significantly worse in ever-hospitalised as compared with never-hospitalised participants and was related to 6MWD and exertional SpO2 but not SGRQ or mMRC scores. TRIAL REGISTRATION NUMBER: NCT05014516.


Subject(s)
COVID-19 , Respiration Disorders , COVID-19/complications , Humans , Magnetic Resonance Imaging , Respiratory Function Tests , Xenon Isotopes
4.
Cells ; 11(1)2021 12 22.
Article in English | MEDLINE | ID: covidwho-1580996

ABSTRACT

Patients with COPD may be at an increased risk for severe illness from COVID-19 because of ACE2 upregulation, the entry receptor for SARS-CoV-2. Chronic exposure to cigarette smoke, the main risk factor for COPD, increases pulmonary ACE2. How ACE2 expression is controlled is not known but may involve HuR, an RNA binding protein that increases protein expression by stabilizing mRNA. We hypothesized that HuR would increase ACE2 protein expression. We analyzed scRNA-seq data to profile ELAVL1 expression in distinct respiratory cell populations in COVID-19 and COPD patients. HuR expression and cellular localization was evaluated in COPD lung tissue by multiplex immunohistochemistry and in human lung cells by imaging flow cytometry. The regulation of ACE2 expression was evaluated using siRNA-mediated knockdown of HuR. There is a significant positive correlation between ELAVL1 and ACE2 in COPD cells. HuR cytoplasmic localization is higher in smoker and COPD lung tissue; there were also higher levels of cleaved HuR (CP-1). HuR binds to ACE2 mRNA but knockdown of HuR does not change ACE2 protein levels in primary human lung fibroblasts (HLFs). Our work is the first to investigate the association between ACE2 and HuR. Further investigation is needed to understand the mechanistic underpinning behind the regulation of ACE2 expression.


Subject(s)
Angiotensin-Converting Enzyme 2/genetics , COVID-19/genetics , ELAV-Like Protein 1/genetics , Gene Expression Regulation , Lung/metabolism , Aged , Angiotensin-Converting Enzyme 2/metabolism , COVID-19/metabolism , COVID-19/virology , Cells, Cultured , ELAV-Like Protein 1/metabolism , Female , Fibroblasts/metabolism , Gene Expression Profiling/methods , Humans , Lung/pathology , Lung/virology , Male , Middle Aged , Pulmonary Disease, Chronic Obstructive/genetics , Pulmonary Disease, Chronic Obstructive/metabolism , Pulmonary Disease, Chronic Obstructive/virology , RNA Interference , RNA-Seq/methods , SARS-CoV-2/physiology , Single-Cell Analysis/methods
5.
Viruses ; 13(11)2021 11 08.
Article in English | MEDLINE | ID: covidwho-1512696

ABSTRACT

Survivors of severe SARS-CoV-2 infections frequently suffer from a range of post-infection sequelae. Whether survivors of mild or asymptomatic infections can expect any long-term health consequences is not yet known. Herein we investigated lasting changes to soluble inflammatory factors and cellular immune phenotype and function in individuals who had recovered from mild SARS-CoV-2 infections (n = 22), compared to those that had recovered from other mild respiratory infections (n = 11). Individuals who had experienced mild SARS-CoV-2 infections had elevated levels of C-reactive protein 1-3 months after symptom onset, and changes in phenotype and function of circulating T-cells that were not apparent in individuals 6-9 months post-symptom onset. Markers of monocyte activation, and expression of adherence and chemokine receptors indicative of altered migratory capacity, were also higher at 1-3 months post-infection in individuals who had mild SARS-CoV-2, but these were no longer elevated by 6-9 months post-infection. Perhaps most surprisingly, significantly more T-cells could be activated by polyclonal stimulation in individuals who had recently experienced a mild SARS-CoV-2, infection compared to individuals with other recent respiratory infections. These data are indicative of prolonged immune activation and systemic inflammation that persists for at least three months after mild or asymptomatic SARS-CoV-2 infections.


Subject(s)
Asymptomatic Infections , COVID-19/immunology , Cytokines/metabolism , Leukocytes/immunology , Leukocytes/metabolism , Respiratory Tract Infections/immunology , SARS-CoV-2/immunology , Adult , Aged , Antibodies, Viral , Biomarkers , C-Reactive Protein/immunology , C-Reactive Protein/metabolism , COVID-19/virology , Cytokines/immunology , Female , Humans , Immunophenotyping/methods , Inflammation/metabolism , Inflammation/virology , Lymphocyte Activation , Male , Middle Aged , Respiratory Tract Infections/virology , Spike Glycoprotein, Coronavirus/immunology , Survivors , T-Lymphocytes/immunology , T-Lymphocytes/metabolism
6.
Am J Physiol Lung Cell Mol Physiol ; 320(1): L152-L157, 2021 01 01.
Article in English | MEDLINE | ID: covidwho-1054733

ABSTRACT

The COVID-19 pandemic is associated with severe pneumonia and acute respiratory distress syndrome leading to death in susceptible individuals. For those who recover, post-COVID-19 complications may include development of pulmonary fibrosis. Factors contributing to disease severity or development of complications are not known. Using computational analysis with experimental data, we report that idiopathic pulmonary fibrosis (IPF)- and chronic obstructive pulmonary disease (COPD)-derived lung fibroblasts express higher levels of angiotensin-converting enzyme 2 (ACE2), the receptor for SARS-CoV-2 entry and part of the renin-angiotensin system that is antifibrotic and anti-inflammatory. In preclinical models, we found that chronic exposure to cigarette smoke, a risk factor for both COPD and IPF and potentially for SARS-CoV-2 infection, significantly increased pulmonary ACE2 protein expression. Further studies are needed to understand the functional implications of ACE2 on lung fibroblasts, a cell type that thus far has received relatively little attention in the context of COVID-19.


Subject(s)
Angiotensin-Converting Enzyme 2/biosynthesis , COVID-19/pathology , Fibroblasts/metabolism , Idiopathic Pulmonary Fibrosis/pathology , Pulmonary Disease, Chronic Obstructive/pathology , Adult , Animals , Female , Gene Expression Regulation/drug effects , Humans , Male , Mice , Mice, Inbred C57BL , Middle Aged , Receptors, Virus/biosynthesis , Respiratory Distress Syndrome/pathology , Respiratory Distress Syndrome/virology , SARS-CoV-2/metabolism , Smoke/adverse effects
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