Determinants of SARS-CoV-2 receptor gene expression in upper and lower airways.
ABSTRACT: The recent outbreak of the severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), which causes coronavirus disease 2019 (COVID-19), has led to a worldwide pandemic. One week after initial symptoms develop, a subset of patients progresses to severe disease, with high mortality and limited treatment options. To design novel interventions aimed at preventing spread of the virus and reducing progression to severe disease, detailed knowledge of the cell types and regulating factors driving cellular entry is urgently needed. Here we assess the expression patterns in genes required for COVID-19 entry into cells and replication, and their regulation by genetic, epigenetic and environmental factors, throughout the respiratory tract using samples collected from the upper (nasal) and lower airways (bronchi). Matched samples from the upper and lower airways show a clear increased expression of these genes in the nose compared to the bronchi and parenchyma. Cellular deconvolution indicates a clear association of these genes with the proportion of secretory epithelial cells. Smoking status was found to increase the majority of COVID-19 related genes including ACE2 and TMPRSS2 but only in the lower airways, which was associated with a significant increase in the predicted proportion of goblet cells in bronchial samples of current smokers. Both acute and second hand smoke were found to increase ACE2 expression in the bronchus. Inhaled corticosteroids decrease ACE2 expression in the lower airways. No significant effect of genetics on ACE2 expression was observed, but a strong association of DNA- methylation with ACE2 and TMPRSS2- mRNA expression was identified in the bronchus.
Project description:It has been reported that angiotensin-converting enzyme 2 (ACE2) and transmembrane serine protease 2 (TMPRSS2) are the main cell entry proteins for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and play a critical role in causing coronavirus disease 2019 (COVID-19). To investigate the expression level of these SARS-CoV-2 host cell entry genes in the lung airway, we used public gene expression datasets. We have found a differential expression of ACE2 and TMPRSS2 in nasal and bronchial airways relative to age and diseases status. Children were found to have significantly lower expression of COVID-19 receptors in the upper and lower airways (nasal and bronchial). Moreover, the lung airway expression of both ACE2 and TMPRSS2 was found to be significantly upregulated in smokers compared with non-smokers, and in patients with chronic obstructive pulmonary disease (COPD) compared with healthy subjects. No difference was observed in the blood expression levels of ACE2 and TMPRSS2 between children and adults, or in COPD or diabetic patients. However, a significant increase in blood expression levels of these genes was observed in patients with essential hypertension, whereas only ACE2 was upregulated in the blood of asthmatics. These results suggest that the observed difference in COVID-19 severity between children and adults could, in part, be attributed to the difference in ACE2 and TMPRSS2 airways tissue expression levels.
Project description:SARS-CoV-2 is causing a pandemic with currently >?29 million confirmed cases and >?900,000 deaths worldwide. The locations and mechanisms of virus entry into the human respiratory tract are incompletely characterized. We analyzed publicly available RNA microarray datasets for SARS-CoV-2 entry receptors and cofactors ACE2, TMPRSS2, BSG (CD147) and FURIN. We found that ACE2 and TMPRSS2 are upregulated in the airways of smokers. In asthmatics, ACE2 tended to be downregulated in nasal epithelium, and TMPRSS2 was upregulated in the bronchi. Furthermore, respiratory epithelia were negative for ACE-2 and TMPRSS2 protein expression while positive for BSG and furin, suggesting a possible alternative entry route for SARS-CoV-2.
Project description:Angiotensin-converting enzyme 2 (ACE2) has been implicated in the pathogenesis of chronic kidney disease (CKD) and is a membrane receptor for severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus responsible for coronavirus disease (COVID-19), whereas transmembrane protease, serine 2 (TMPRSS2) is involved in viral attachment. Together, tissue expression of ACE2 and TMPRSS2 may determine infection. Sex, age, body mass index (BMI), and CKD are clinical risk factors for COVID-19 severity, but the relationships between kidney ACE2 and TMPRSS2 expression and these clinical variables are unknown. Accordingly, we obtained renal tubulointerstitial and glomerular microarray expression data and clinical variables from healthy living donors (HLD) and patients with CKD from the European Renal cDNA Bank. ACE2 expression was similar in the tubulointerstitium of the two groups, but greater in females than males in HLD (P = 0.005) and CKD (P < 0.0001). ACE2 expression was lower in glomeruli of CKD patients compared to HLD (P = 0.0002) and lower in males than females. TMPRSS2 expression was similar in the tubulointerstitium but lower in glomeruli of CKD patients compared to HLD (P < 0.0001). There was a strong relationship between ACE2 and TMPRSS2 expression in the glomerulus (r = 0.51, P < 0.0001). In CKD, there was a relationship between tubulointerstitial ACE2 expression and estimated glomerular filtration rate (r = 0.36, P < 0.0001) and age (r = -0.17, P = 0.03), but no relationship with BMI. There were no relationships between TMPRSS2 expression and clinical variables. Genes involved in inflammation (CCL2, IL6, and TNF) and fibrosis (COL1A1, TGFB1, and FN1) were inversely correlated with ACE2 expression. In summary, kidney expression of ACE2 and TMPRSS2 differs in HLD and CKD. ACE2 is related to sex and eGFR. ACE2 is also associated with expression of genes implicated in inflammation and fibrosis.
Project description:BACKGROUND:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has dramatically changed our world, country, communities, and families. There is controversy regarding risk factors for severe COVID-19 disease. It has been suggested that asthma and allergy are not highly represented as comorbid conditions associated with COVID-19. OBJECTIVE:Our aim was to extend our work in IL-13 biology to determine whether airway epithelial cell expression of 2 key mediators critical for SARS-CoV-2 infection, namely, angiotensin-converting enzyme 2 (ACE2) and transmembrane protease, serine 2 (TMPRSS2), are modulated by IL-13. METHODS:We determined effects of IL-13 treatment on ACE2 and TMPRSS2 expression ex vivo in primary airway epithelial cells from participants with and without type 2 asthma obtained by bronchoscopy. We also examined expression of ACE2 and TMPRSS2 in 2 data sets containing gene expression data from nasal and airway epithelial cells from children and adults with asthma and allergic rhinitis. RESULTS:IL-13 significantly reduced ACE2 and increased TMPRSS2 expression ex vivo in airway epithelial cells. In 2 independent data sets, ACE2 expression was significantly reduced and TMPRSS2 expression was significantly increased in the nasal and airway epithelial cells in type 2 asthma and allergic rhinitis. ACE2 expression was significantly negatively associated with type 2 cytokines, whereas TMPRSS2 expression was significantly positively associated with type 2 cytokines. CONCLUSION:IL-13 modulates ACE2 and TMPRSS2 expression in airway epithelial cells in asthma and atopy. This deserves further study with regard to any effects that asthma and atopy may render in the setting of COVID-19 infection.
Project description:Severe acute respiratory syndrome-coronavirus 2 (SARS-CoV-2) has rapidly caused a global pandemic associated with a novel respiratory infection: coronavirus disease-19 (COVID-19). Angiotensin-converting enzyme-2 (ACE2) is necessary to facilitate SARS-CoV-2 infection, but-owing to its essential metabolic roles-it may be difficult to target it in therapies. Transmembrane protease serine 2 (TMPRSS2), which interacts with ACE2, may be a better candidate for targeted therapies. Using publicly available expression data, we show that both ACE2 and TMPRSS2 are expressed in many host tissues, including lung. The highest expression of ACE2 is found in the testes, whereas the prostate displays the highest expression of TMPRSS2. Given the increased severity of disease among older men with SARS-CoV-2 infection, we address the potential roles of ACE2 and TMPRSS2 in their contribution to the sex differences in severity of disease. We show that expression levels of ACE2 and TMPRSS2 are overall comparable between men and women in multiple tissues, suggesting that differences in the expression levels of TMPRSS2 and ACE2 in the lung and other non-sex-specific tissues may not explain the gender disparities in severity of SARS CoV-2. However, given their instrumental roles for SARS-CoV-2 infection and their pleiotropic expression, targeting the activity and expression levels of TMPRSS2 is a rational approach to treat COVID-19.
Project description:BACKGROUND:Coronavirus Disease 2019 (COVID-19), caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), has now been confirmed worldwide. Yet, COVID-19 is strangely and tragically selective. Morbidity and mortality due to COVID19 rise dramatically with age and co-existing health conditions, including cancer and cardiovascular diseases. Human genetic factors may contribute to the extremely high transmissibility of SARS-CoV-2 and to the relentlessly progressive disease observed in a small but significant proportion of infected individuals, but these factors are largely unknown. MAIN BODY:In this study, we investigated genetic susceptibility to COVID-19 by examining DNA polymorphisms in ACE2 and TMPRSS2 (two key host factors of SARS-CoV-2) from ~?81,000 human genomes. We found unique genetic susceptibility across different populations in ACE2 and TMPRSS2. Specifically, ACE2 polymorphisms were found to be associated with cardiovascular and pulmonary conditions by altering the angiotensinogen-ACE2 interactions, such as p.Arg514Gly in the African/African-American population. Unique but prevalent polymorphisms (including p.Val160Met (rs12329760), an expression quantitative trait locus (eQTL)) in TMPRSS2, offer potential explanations for differential genetic susceptibility to COVID-19 as well as for risk factors, including those with cancer and the high-risk group of male patients. We further discussed that polymorphisms in ACE2 or TMPRSS2 could guide effective treatments (i.e., hydroxychloroquine and camostat) for COVID-19. CONCLUSION:This study suggested that ACE2 or TMPRSS2 DNA polymorphisms were likely associated with genetic susceptibility of COVID-19, which calls for a human genetics initiative for fighting the COVID-19 pandemic.
Project description:Zoonotically transmitted coronaviruses are responsible for three disease outbreaks since 2002, including the current COVID-19 pandemic, caused by SARS-CoV-2. Its efficient transmission and range of disease severity raise questions regarding the contributions of virus-receptor interactions. ACE2 is a host ectopeptidase and the receptor for SARS-CoV-2. Despite numerous reports describing ACE2 mRNA abundance and tissue distribution, there remains a paucity of data evaluating ACE2 protein and its correlation with other SARS-CoV-2 susceptibility factors. Here, we systematically examined the human upper and lower respiratory tract using single-cell RNA sequencing and immunohistochemistry to determine receptor expression and evaluated its association with risk factors for severe COVID-19. Our results reveal that ACE2 protein is highest within the sinonasal cavity and pulmonary alveoli, sites of presumptive viral transmission and severe disease development, respectively. In the lung parenchyma, ACE2 protein was found on the apical surface of a small subset of alveolar type II cells and colocalized with TMPRSS2, a cofactor for SARS-CoV2 entry. ACE2 protein was not increased by pulmonary risk factors for severe COVID-19. However, ACE2 protein was increased in children, a demographic with a reduced incidence of severe COVID-19. These results offer new insights into ACE2 localization and function in susceptibility to COVID-19.
Project description:AIMS:Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) directly binds to ACE2 (angiotensin-converting enzyme 2) to facilitate cellular entry. Compared with the lung or respiratory tract, the human heart exhibits greater ACE2 expression. However, little substantial damage was found in the heart tissue, and no viral particles were observed in the cardiac myocytes. This study aims to analyse ACE2 and SARS-CoV-2 spike (S) protein proteases at the single-cell level, to explore the cardiac involvement in COVID-19 and improve our understanding of the potential cardiovascular implications of COVID-19. METHODS AND RESULTS:With meta-analysis, the prevalence of cardiac injury in COVID-19 patients varies from 2% [95% confidence interval (CI) 0-5%, I2 = 0%] in non-ICU patients to 59% (95% CI 48-71%, I2 = 85%) in non-survivors. With public single-cell sequence data analysis, ACE2 expression in the adult human heart is higher than that in the lung (adjusted P < 0.0001). Inversely, the most important S protein cleavage protease TMPRSS2 (transmembrane protease serine protease-2) in the heart exhibits an extremely lower expression than that in the lung (adjusted P < 0.0001), which may restrict entry of SARS-CoV-2 into cardiac cells. Furthermore, we discovered that other S protein proteases, CTSL (cathepsin L) and FURIN (furin, paired basic amino acid cleaving enzyme), were expressed in the adult heart at a similar level to that in the lung, which may compensate for TMPRSS2, mediating cardiac involvement in COVID-19. CONCLUSION:Compared with the lung, ACE2 is relatively more highly expressed in the human heart, while the key S protein priming protease, TMPRSS2, is rarely expressed. The low percentage of ACE2+/TMPRSS2+ cells reduced heart vulnerability to SARS-CoV-2 to some degree. CTSL and FURIN may compensate for S protein priming to mediate SARS-CoV-2 infection of the heart.
Project description:BACKGROUND:Zoonotically transmitted coronaviruses are responsible for three disease outbreaks since 2002, including the current COVID-19 pandemic, caused by SARS-CoV-2. Its efficient transmission and range of disease severity raise questions regarding the contributions of virus-receptor interactions. ACE2 is a host ectopeptidase and the receptor for SARS-CoV-2. Numerous reports describe ACE2 mRNA abundance and tissue distribution; however, mRNA abundance is not always representative of protein levels. Currently, there is limited data evaluating ACE2 protein and its correlation with other SARS-CoV-2 susceptibility factors. MATERIALS AND METHODS:We systematically examined the human upper and lower respiratory tract using single-cell RNA sequencing and immunohistochemistry to determine receptor expression and evaluated its association with risk factors for severe COVID-19. FINDINGS:Our results reveal that ACE2 protein is highest within regions of the sinonasal cavity and pulmonary alveoli, sites of presumptive viral transmission and severe disease development, respectively. In the lung parenchyma, ACE2 protein was found on the apical surface of a small subset of alveolar type II cells and colocalized with TMPRSS2, a cofactor for SARS-CoV2 entry. ACE2 protein was not increased by pulmonary risk factors for severe COVID-19. Additionally, ACE2 protein was not reduced in children, a demographic with a lower incidence of severe COVID-19. INTERPRETATION:These results offer new insights into ACE2 protein localization in the human respiratory tract and its relationship with susceptibility factors to COVID-19.
Project description:Coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and has resulted in hundreds of thousands of deaths worldwide. While the majority of people with COVID-19 won't require hospitalization, those who do may experience severe life-threatening complications, including acute respiratory distress syndrome. SARS-CoV-2 infects human cells by binding to the cellular surface protein angiotensin-converting enzyme 2 (ACE2); in addition, the cellular transmembrane serine protease 2 (TMPRSS2) is needed for priming of the spike (S) protein of the virus. Virus entry may also depend on the activity of the endosomal/lysosomal cysteine proteases cathepsin B, L (CTSB, CTSL) although their activity is likely dispensable. Given that the uncertainty of how COVID-19 kills, hampers doctors' ability to choose treatments the need for a deep understanding of COVID-19 biology is urgent. Herein, we performed an expression profiling meta-analysis of ACE2, TMPRSS2 and CTSB/L genes (and proteins) in public repository databases and found that all are widely expressed in human tissues; also, the ACE2 and TMPRSS2 genes tend to be co-regulated. The ACE2 and TMPRSS genes expression is (among others) suppressed by TNF, and is induced by pro-inflammatory conditions including obesity, Barrett's esophagus, stomach infection by helicobacter pylori, diabetes, autoimmune diseases and oxidized LDL; by exercise, as well as by growth factors, viruses' infections, cigarette smoke, interferons and androgens. Regarding currently investigated therapies interferon-beta induced ACE2 gene expression in bronchial epithelial cells, while chloroquine tends to upregulate CTSB/L genes. Finally, we analyzed KEGG pathways modulated by ACE2, TMPRSS2 and CTSB/L and probed DrugBank for drugs that target modules of the affected pathways. Our data indicate possible novel high-risk groups for COVID-19; provide a rich resource for future investigations of its pathogenesis and highlight the therapeutic challenges we face.