Highlights d BALF cell transcriptome indicates robust innate immune responses in COVID-19 patients d COVID-19 patients exhibit chemokine-dominant hypercytokinemia d ISGs are highly expressed in COVID-19 patients and exhibit pathogenic potential
An outbreak of pneumonia caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) that started in Wuhan, China, at the end of 2019 has become a global pandemic. Both SARS-CoV-2 and SARS-CoV enter host cells via the angiotensin-converting enzyme 2 (ACE2) receptor, which is expressed in various human organs. We have reviewed previously published studies on SARS and recent studies on SARS-CoV-2 infection, named coronavirus disease 2019 (COVID-19) by the World Health Organization (WHO), confirming that many other organs besides the lungs are vulnerable to the virus. ACE2 catalyzes angiotensin II conversion to angiotensin-(1–7), and the ACE2/angiotensin-(1–7)/MAS axis counteracts the negative effects of the renin-angiotensin system (RAS), which plays important roles in maintaining the physiological and pathophysiological balance of the body. In addition to the direct viral effects and inflammatory and immune factors associated with COVID-19 pathogenesis, ACE2 downregulation and the imbalance between the RAS and ACE2/angiotensin-(1–7)/MAS after infection may also contribute to multiple organ injury in COVID-19. The SARS-CoV-2 spike glycoprotein, which binds to ACE2, is a potential target for developing specific drugs, antibodies, and vaccines. Restoring the balance between the RAS and ACE2/angiotensin-(1–7)/MAS may help attenuate organ injuries.
Graphical abstract
SARS-CoV-2 enters lung cells via the ACE2 receptor. The cell-free and macrophage-phagocytosed virus can spread to other organs and infect ACE2-expressing cells at local sites, causing multi-organ injury.
An elevated level of viral diversity was found in some SARS-CoV-2 infected patients, indicating the risk of rapid evolution of the virus. Although no evidence for the transmission of intra-host variants was found, the risk should not be overlooked.
Abstract:Background A novel coronavirus (SARS-CoV-2) has infected more than 75,000 individuals and spread to over 20 countries. It is still unclear how fast the virus evolved and how the virus interacts with other microorganisms in the lung.
MethodsWe have conducted metatranscriptome sequencing for the bronchoalveolar lavage fluid of eight SARS-CoV-2 patients, 25 community-acquired pneumonia (CAP) patients, and 20 healthy controls.
ResultsThe median number of intra-host variants was 1-4 in SARS-CoV-2 infected patients, which ranged between 0 and 51 in different samples. The distribution of variants on genes was similar to those observed in the population data (110 sequences).However, very few intra-host variants were observed in the population as polymorphism, implying either a bottleneck or purifying selection involved in the transmission of the virus, or a consequence of the limited diversity represented in the current polymorphism data. Although current evidence did not support the transmission of intra-host variants in a person-to-person spread, the risk should not be overlooked.The microbiota in SARS-CoV-2 infected patients was similar to those in CAP, either dominated by the pathogens or with elevated levels of oral and upper respiratory commensal bacteria.Conclusion SARS-CoV-2 evolves in vivo after infection, which may affect its virulence, infectivity, and transmissibility. Although how the intra-host variant spreads in the population is still elusive, it is necessary to strengthen the surveillance of the viral Downloaded from https://academic.oup.com/cid/advance-article-abstract/doi/10.1093/cid/ciaa203/5780800 by guest on 16 March 2020 4 evolution in the population and associated clinical changes.
The aim of the present study was to examine whether erastin influences radioresistance in non-small cell lung cancer (NSCLC) cells and produce a preliminary investigation into its mechanism of action. The radioresistant subtype of NSCLC cells, A549-R and H460-R, were induced by high-dose hypofractionated irradiation. Erastin was used to treat the radioresistant cells and radiosensitivity was examined by colony formation assays. Cell death was determined after the cells were treated with erastin, irradiation (IR) or erastin together with IR. The expression of glutathione peroxidase 4 (GPX4) expression in the parental cells and radioresistance cells was detected by western blotting. GPX4 expression in the radioresistance cells was subsequently inhibited, radiosensitivity and cell death was measured, and erastin enhanced radiosensitivity in A549-R and H460-R cells. Erastin and IR exhibited a combined effect on killing cells, as co-treatment with erastin and IR demonstrated a higher effect on killing cells compared with erastin or IR alone. GPX4 expression was inhibited by erastin in the radioresistant cells. Inhibiting GPX4 expression also radiosensitized NSCLC cells to radiation in the radioresistant cell lines. Erastin-induced and GPX4-inhibition-induced cell death could partially be rescued by deferoxamine, but not Z-VAD-FMK and olaparib, which indicated that erastin and GPX4-inhibition induced ferroptosis in the radioresistant cells. Erastin decreased radioresistance of NSCLC cells partially by inducing GPX4-mediated ferroptosis.
BackgroundAcute respiratory infections (ARIs) are a great public health challenge globally. The prevalence of respiratory viruses in patients with ARIs attending at different hospital settings is fully undetermined.MethodsLaboratory-based surveillance for ARIs was conducted at inpatient and outpatient settings of 11 hospitals in North China. The first 2–5 patients with ARIs were recruited in each hospital weekly from 2012 through 2015. The presence of respiratory viruses was screened by PCR assays. The prevalence of respiratory viruses was determined and compared between patients at different hospital settings.ResultsA total of 3487 hospitalized cases and 6437 outpatients/Emergency Department (ED) patients were enrolled. The most commonly detected viruses in the hospitalized cases were respiratory syncytial virus (RSV, 33.3%) in children less than two years old, adenoviruses (13.0%) in patients 15–34 years old, and influenza viruses (IFVs, 9.6%) in patients ≥65 years. IFVs were the most common virus in outpatient/ED patients across all age groups (22.7%). After controlling for the confounders caused by other viruses and covariates, adenoviruses (adjusted odds ratio [aOR]: 3.97, 99% confidence interval [99% CI]: 2.19–7.20) and RSV (aOR: 2.04, 99% CI: 1.34–3.11) were independently associated with increased hospitalization in children, as well as adenoviruses in adults (aOR: 2.14, 99% CI: 1.19–3.85). Additionally, co-infection of RSV with IFVs was associated with increased hospitalization in children (aOR: 12.20, 99% CI: 2.65–56.18).ConclusionsA substantial proportion of ARIs was associated with respiratory viruses in North China. RSV, adenoviruses, and co-infection of RSV and IFVs were more frequent in hospitalized children (or adenoviruses in adults), which might predict the severity of ARIs. Attending clinicians should be more vigilant of these infections.Electronic supplementary materialThe online version of this article (10.1186/s12879-018-2982-3) contains supplementary material, which is available to authorized users.
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