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1.
Int J Mol Sci ; 23(3)2022 Jan 19.
Article in English | MEDLINE | ID: covidwho-1625123

ABSTRACT

SARS-CoV-2 uses the human cell surface protein angiotensin converting enzyme 2 (ACE2) as the receptor by which it gains access into lung and other tissue. Early in the pandemic, there was speculation that a number of commonly used medications-including ibuprofen and other non-steroidal anti-inflammatory drugs (NSAIDs)-have the potential to upregulate ACE2, thereby possibly facilitating viral entry and increasing the severity of COVID-19. We investigated the influence of the NSAIDS with a range of cyclooxygenase (COX)1 and COX2 selectivity (ibuprofen, flurbiprofen, etoricoxib) and paracetamol on the level of ACE2 mRNA/protein expression and activity as well as their influence on SARS-CoV-2 infection levels in a Caco-2 cell model. We also analysed the ACE2 mRNA/protein levels and activity in lung, heart and aorta in ibuprofen treated mice. The drugs had no effect on ACE2 mRNA/protein expression and activity in the Caco-2 cell model. There was no up-regulation of ACE2 mRNA/protein expression and activity in lung, heart and aorta tissue in ibuprofen-treated mice in comparison to untreated mice. Viral load was significantly reduced by both flurbiprofen and ibuprofen at high concentrations. Ibuprofen, flurbiprofen, etoricoxib and paracetamol demonstrated no effects on ACE2 expression or activity in vitro or in vivo. Higher concentrations of ibuprofen and flurbiprofen reduced SARS-CoV-2 replication in vitro.


Subject(s)
Angiotensin-Converting Enzyme 2 , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , COVID-19/genetics , Acetaminophen/pharmacology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/metabolism , COVID-19/pathology , Caco-2 Cells , Disease Progression , Enzyme Activation/drug effects , Etoricoxib/pharmacology , Flurbiprofen/pharmacology , Gene Expression Regulation, Enzymologic/drug effects , Humans , Ibuprofen/pharmacology , Male , Mice , Mice, Inbred C57BL , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Virus Internalization/drug effects
2.
Front Immunol ; 12: 784989, 2021.
Article in English | MEDLINE | ID: covidwho-1603282

ABSTRACT

Effective treatment strategies for severe coronavirus disease (COVID-19) remain scarce. Hydrolysis of membrane-embedded, inert sphingomyelin by stress responsive sphingomyelinases is a hallmark of adaptive responses and cellular repair. As demonstrated in experimental and observational clinical studies, the transient and stress-triggered release of a sphingomyelinase, SMPD1, into circulation and subsequent ceramide generation provides a promising target for FDA-approved drugs. Here, we report the activation of sphingomyelinase-ceramide pathway in 23 intensive care patients with severe COVID-19. We observed an increase of circulating activity of sphingomyelinase with subsequent derangement of sphingolipids in serum lipoproteins and from red blood cells (RBC). Consistent with increased ceramide levels derived from the inert membrane constituent sphingomyelin, increased activity of acid sphingomyelinase (ASM) accurately distinguished the patient cohort undergoing intensive care from healthy controls. Positive correlational analyses with biomarkers of severe clinical phenotype support the concept of an essential pathophysiological role of ASM in the course of SARS-CoV-2 infection as well as of a promising role for functional inhibition with anti-inflammatory agents in SARS-CoV-2 infection as also proposed in independent observational studies. We conclude that large-sized multicenter, interventional trials are now needed to evaluate the potential benefit of functional inhibition of this sphingomyelinase in critically ill patients with COVID-19.


Subject(s)
COVID-19/metabolism , Ceramides/metabolism , Signal Transduction , Sphingomyelin Phosphodiesterase/metabolism , Anti-Inflammatory Agents/therapeutic use , COVID-19/drug therapy , COVID-19/virology , Ceramides/blood , Enzyme Activation , Erythrocyte Membrane/metabolism , Erythrocytes/metabolism , Fatty Acids/metabolism , Humans , Intensive Care Units , Patient Acuity , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Sphingomyelin Phosphodiesterase/blood , Sphingomyelins/metabolism
3.
BMC Plant Biol ; 21(1): 600, 2021 Dec 18.
Article in English | MEDLINE | ID: covidwho-1591084

ABSTRACT

BACKGROUND: Overuse of chemical fertilizer highly influences grain filling rate and quality of rice grain. Biochar is well known for improving plant growth and grain yield under lower chemical fertilization. Therefore field trials were conducted in the early and late seasons of 2019 at Guangxi University, China to investigate the effects of combined biochar (B) and nitrogen (N) application on rice yield and yield components. There were a total of eight treatments: N1B0, 135 kg N ha- 1+ 0 t B ha- 1; N2B0,180 kg N ha- 1+ 0 t B ha- 1; N1B1,135 kg N ha- 1+ 10 t B ha- 1; N1B2,135kg N ha- 1+ 20 t B ha- 1; N1B3,135 kg N ha- 1+ 30 t B ha- 1; N2B1,180 kg N ha- 1+ 10 t B ha- 1; N2B2,180 kg N ha- 1+ 20 t B ha- 1; and N2B3,180 kg N ha- 1+ 30 t B ha- 1. RESULTS: Biochar application at 30 t ha- 1combined with low N application (135 kg ha- 1) increased the activity of starch-metabolizing enzymes (SMEs) during the early and late seasons compared with treatments without biochar. The grain yield, amylose concentration, and starch content of rice were increased in plots treated with 30 t B ha-1and low N. RT-qPCR analysis showed that biochar addition combined with N fertilizer application increased the expression of AGPS2b, SSS1, GBSS1, and GBSE11b, which increased the activity of SMEs during the grain-filling period. CONCLUSION: Our results suggest that the use of 20 to 30 t B ha- 1coupled with 135 kg N ha- 1 is optimal for improving the grain yield and quality of rice.


Subject(s)
Charcoal/pharmacology , Fertilizers , Nitrogen/pharmacology , Oryza/drug effects , 1,4-alpha-Glucan Branching Enzyme/genetics , 1,4-alpha-Glucan Branching Enzyme/metabolism , Agriculture , Amylose/metabolism , China , Enzyme Activation , Enzymes/metabolism , Gene Expression Regulation, Plant/drug effects , Genes, Plant , Oryza/enzymology , Oryza/genetics , Oryza/metabolism , Plant Proteins/genetics , Plant Proteins/metabolism , Starch/metabolism
4.
J Biol Chem ; 298(1): 101518, 2022 01.
Article in English | MEDLINE | ID: covidwho-1587356

ABSTRACT

Understanding the core replication complex of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is essential to the development of novel coronavirus-specific antiviral therapeutics. Among the proteins required for faithful replication of the SARS-CoV-2 genome are nonstructural protein 14 (NSP14), a bifunctional enzyme with an N-terminal 3'-to-5' exoribonuclease (ExoN) and a C-terminal N7-methyltransferase, and its accessory protein, NSP10. The difficulty in producing pure and high quantities of the NSP10/14 complex has hampered the biochemical and structural study of these important proteins. We developed a straightforward protocol for the expression and purification of both NSP10 and NSP14 from Escherichia coli and for the in vitro assembly and purification of a stoichiometric NSP10/14 complex with high yields. Using these methods, we observe that NSP10 provides a 260-fold increase in kcat/Km in the exoribonucleolytic activity of NSP14 and enhances protein stability. We also probed the effect of two small molecules on NSP10/14 activity, remdesivir monophosphate and the methyltransferase inhibitor S-adenosylhomocysteine. Our analysis highlights two important factors for drug development: first, unlike other exonucleases, the monophosphate nucleoside analog intermediate of remdesivir does not inhibit NSP14 activity; and second, S-adenosylhomocysteine modestly activates NSP14 exonuclease activity. In total, our analysis provides insights for future structure-function studies of SARS-CoV-2 replication fidelity for the treatment of coronavirus disease 2019.


Subject(s)
Antiviral Agents/pharmacology , Exoribonucleases/metabolism , SARS-CoV-2/drug effects , SARS-CoV-2/enzymology , Viral Nonstructural Proteins/metabolism , Enzyme Activation , Virus Replication/drug effects
5.
Front Immunol ; 12: 750969, 2021.
Article in English | MEDLINE | ID: covidwho-1551506

ABSTRACT

The COVID-19 is an infectious disease caused by SARS-CoV-2 infection. A large number of clinical studies found high-level expression of pro-inflammatory cytokines in patients infected with SARS-CoV-2, which fuels the rapid development of the disease. However, the specific molecular mechanism is still unclear. In this study, we found that SARS-CoV-2 Nsp5 can induce the expression of cytokines IL-1ß, IL-6, TNF-α, and IL-2 in Calu-3 and THP1 cells. Further research found that Nsp5 enhances cytokine expression through activating the NF-κB signaling pathway. Subsequently, we investigated the upstream effectors of the NF-κB signal pathway on Nsp5 overexpression and discovered that Nsp5 increases the protein level of MAVS. Moreover, Nsp5 can promote the SUMOylation of MAVS to increase its stability and lead to increasing levels of MAVS protein, finally triggering activation of NF-κB signaling. The knockdown of MAVS and the inhibitor of SUMOylation treatment can attenuate Nsp5-mediated NF-κB activation and cytokine induction. We identified a novel role of SARS-CoV-2 Nsp5 to enhance cytokine production by activating the NF-κB signaling pathway.


Subject(s)
Adaptor Proteins, Signal Transducing/metabolism , Coronavirus 3C Proteases/immunology , Cytokines/biosynthesis , NF-kappa B/metabolism , SARS-CoV-2/immunology , Sumoylation/physiology , Adaptor Proteins, Signal Transducing/genetics , Animals , COVID-19/immunology , Cell Line , Chlorocebus aethiops , Enzyme Activation/drug effects , HEK293 Cells , Humans , Immunity, Innate/immunology , Interleukin-1beta/biosynthesis , Interleukin-2/biosynthesis , Interleukin-6/biosynthesis , Signal Transduction/physiology , Sumoylation/drug effects , THP-1 Cells , Tumor Necrosis Factor-alpha/biosynthesis , Vero Cells
6.
Angiogenesis ; 24(3): 677-693, 2021 08.
Article in English | MEDLINE | ID: covidwho-1549443

ABSTRACT

Endothelial barrier disruption and vascular leak importantly contribute to organ dysfunction and mortality during inflammatory conditions like sepsis and acute respiratory distress syndrome. We identified the kinase Arg/Abl2 as a mediator of endothelial barrier disruption, but the role of Arg in endothelial monolayer regulation and its relevance in vivo remain poorly understood. Here we show that depletion of Arg in endothelial cells results in the activation of both RhoA and Rac1, increased cell spreading and elongation, redistribution of integrin-dependent cell-matrix adhesions to the cell periphery, and improved adhesion to the extracellular matrix. We further show that Arg is activated in the endothelium during inflammation, both in murine lungs exposed to barrier-disruptive agents, and in pulmonary microvessels of septic patients. Importantly, Arg-depleted endothelial cells were less sensitive to barrier-disruptive agents. Despite the formation of F-actin stress fibers and myosin light chain phosphorylation, Arg depletion diminished adherens junction disruption and intercellular gap formation, by reducing the disassembly of cell-matrix adhesions and cell retraction. In vivo, genetic deletion of Arg diminished vascular leak in the skin and lungs, in the presence of a normal immune response. Together, our data indicate that Arg is a central and non-redundant regulator of endothelial barrier integrity, which contributes to cell retraction and gap formation by increasing the dynamics of adherens junctions and cell-matrix adhesions in a Rho GTPase-dependent fashion. Therapeutic inhibition of Arg may provide a suitable strategy for the treatment of a variety of clinical conditions characterized by vascular leak.


Subject(s)
Extracellular Matrix/metabolism , Gap Junctions/enzymology , Human Umbilical Vein Endothelial Cells/enzymology , Protein-Tyrosine Kinases/metabolism , Pulmonary Alveoli/enzymology , Animals , Cell Adhesion/genetics , Enzyme Activation , Extracellular Matrix/genetics , Gap Junctions/genetics , Humans , Inflammation/enzymology , Inflammation/genetics , Mice , Mice, Knockout , Protein-Tyrosine Kinases/genetics
7.
Hypertension ; 79(2): 365-378, 2022 02.
Article in English | MEDLINE | ID: covidwho-1541968

ABSTRACT

ACE (angiotensin-converting enzyme)-2 as the target for SARS-CoV-2 also negatively regulates the renin-angiotensin system. Pathological activation of ADAM17 (A disintegrin and metalloproteinase-17) may potentiate inflammation and diminish ACE2-mediated tissue protection through proteolytic shedding, contributing to SARS-CoV-2 pathogenesis. We aim to examine plasma soluble ACE2 and angiotensin profiles in relation to outcomes by enrolling consecutive patients admitted for COVID-19 with baseline blood collection at admission and repeated sampling at 7 days. The primary outcome was 90-day mortality, and secondary outcomes were the incidence of end-organ injuries. Overall, 242 patients were included, the median age was 63 (52-74) years, 155 (64.0%) were men, and 57 (23.6%) patients reached the primary end point. Baseline soluble ACE2 was elevated in COVID-19 but was not associated with disease severity or mortality. In contrast, an upward trajectory of soluble ACE2 at repeat sampling was independently associated with an elevated risk of mortality and incidence of acute myocardial injury and circulatory shock. Similarly, an increase in soluble tumor necrosis factor receptor levels was also associated with adverse outcomes. Plasma Ang I, Ang 1-7 (angiotensin 1-7) levels, and the Ang 1-7/Ang II (angiotensin II) ratio were elevated during SARS-CoV-2 infection related to downregulation of ACE activity at baseline. Moreover, patients having an upward trajectory of soluble ACE2 were characterized by an imbalance in the Ang 1-7/Ang II ratio. The observed dysregulation of ACE2 and angiotensin peptides with disease progression suggest a potential role of ADAM17 inhibition and enhancing the beneficial Ang 1-7/Mas axis to improve outcomes against SARS-CoV-2 infection.


Subject(s)
Angiotensin II/blood , Angiotensin I/blood , Angiotensin-Converting Enzyme 2/blood , COVID-19/blood , Peptide Fragments/blood , Renin-Angiotensin System/physiology , SARS-CoV-2 , ADAM17 Protein/blood , Aged , COVID-19/mortality , COVID-19/therapy , Enzyme Activation , Female , Follow-Up Studies , Humans , Male , Middle Aged , Prognosis , Prospective Studies , Receptors, Tumor Necrosis Factor, Type I/blood , Receptors, Tumor Necrosis Factor, Type II/blood , Respiration, Artificial , Risk , Treatment Outcome
8.
Viruses ; 13(9)2021 09 14.
Article in English | MEDLINE | ID: covidwho-1411090

ABSTRACT

The porcine epidemic diarrhea virus (PEDV) is an Alphacoronavirus (α-CoV) that causes high mortality in infected piglets, resulting in serious economic losses in the farming industry. Hypericin is a dianthrone compound that has been shown as an antiviral activity on several viruses. Here, we first evaluated the antiviral effect of hypericin in PEDV and found the viral replication and egression were significantly reduced with hypericin post-treatment. As hypericin has been shown in SARS-CoV-2 that it is bound to viral 3CLpro, we thus established a molecular docking between hypericin and PEDV 3CLpro using different software and found hypericin bound to 3CLpro through two pockets. These binding pockets were further verified by another docking between hypericin and PEDV 3CLpro pocket mutants, and the fluorescence resonance energy transfer (FRET) assay confirmed that hypericin inhibits the PEDV 3CLpro activity. Moreover, the alignments of α-CoV 3CLpro sequences or crystal structure revealed that the pockets mediating hypericin and PEDV 3CLpro binding were highly conserved, especially in transmissible gastroenteritis virus (TGEV). We then validated the anti-TGEV effect of hypericin through viral replication and egression. Overall, our results push forward that hypericin was for the first time shown to have an inhibitory effect on PEDV and TGEV by targeting 3CLpro, and it deserves further attention as not only a pan-anti-α-CoV compound but potentially also as a compound of other coronaviral infections.


Subject(s)
Alphacoronavirus/drug effects , Alphacoronavirus/physiology , Anthracenes/pharmacology , Antiviral Agents/pharmacology , Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus Infections/virology , Perylene/analogs & derivatives , Virus Replication/drug effects , Amino Acid Sequence , Animals , Antiviral Agents/chemistry , Chlorocebus aethiops , Coronavirus 3C Proteases/chemistry , Enzyme Activation/drug effects , Models, Molecular , Perylene/pharmacology , Porcine epidemic diarrhea virus/drug effects , Recombinant Proteins , Structure-Activity Relationship , Swine , Swine Diseases/virology , Vero Cells
9.
Viruses ; 13(9)2021 09 12.
Article in English | MEDLINE | ID: covidwho-1411086

ABSTRACT

Our therapeutic arsenal against viruses is very limited and the current pandemic of SARS-CoV-2 highlights the critical need for effective antivirals against emerging coronaviruses. Cellular assays allowing a precise quantification of viral replication in high-throughput experimental settings are essential to the screening of chemical libraries and the selection of best antiviral chemical structures. To develop a reporting system for SARS-CoV-2 infection, we generated cell lines expressing a firefly luciferase maintained in an inactive form by a consensus cleavage site for the viral protease 3CLPro of coronaviruses, so that the luminescent biosensor is turned on upon 3CLPro expression or SARS-CoV-2 infection. This cellular assay was used to screen a metabolism-oriented library of 492 compounds to identify metabolic vulnerabilities of coronaviruses for developing innovative therapeutic strategies. In agreement with recent reports, inhibitors of pyrimidine biosynthesis were found to prevent SARS-CoV-2 replication. Among the top hits, we also identified the NADPH oxidase (NOX) inhibitor Setanaxib. The anti-SARS-CoV-2 activity of Setanaxib was further confirmed using ACE2-expressing human pulmonary cells Beas2B as well as human primary nasal epithelial cells. Altogether, these results validate our cell-based functional assay and the interest of screening libraries of different origins to identify inhibitors of SARS-CoV-2 for drug repurposing or development.


Subject(s)
Antiviral Agents/isolation & purification , Biosensing Techniques/methods , Coronavirus 3C Proteases/metabolism , SARS-CoV-2/physiology , Virus Replication , Animals , Antiviral Agents/pharmacology , Cell Line , Chlorocebus aethiops , Drug Discovery , Drug Evaluation, Preclinical , Enzyme Activation , HEK293 Cells , Humans , Luciferases, Firefly/metabolism , Nasal Mucosa/virology , Pyrazolones/pharmacology , Pyridones/pharmacology , SARS-CoV-2/metabolism , Vero Cells , Virus Internalization/drug effects , Virus Replication/drug effects
10.
Nat Struct Mol Biol ; 28(9): 755-761, 2021 09.
Article in English | MEDLINE | ID: covidwho-1406396

ABSTRACT

Bradykinin and kallidin are endogenous kinin peptide hormones that belong to the kallikrein-kinin system and are essential to the regulation of blood pressure, inflammation, coagulation and pain control. Des-Arg10-kallidin, the carboxy-terminal des-Arg metabolite of kallidin, and bradykinin selectively activate two G protein-coupled receptors, type 1 and type 2 bradykinin receptors (B1R and B2R), respectively. The hyperactivation of bradykinin receptors, termed 'bradykinin storm', is associated with pulmonary edema in COVID-19 patients, suggesting that bradykinin receptors are important targets for COVID-19 intervention. Here we report two G protein-coupled complex structures of human B1R and B2R bound to des-Arg10-kallidin and bradykinin, respectively. Combined with functional analysis, our structures reveal the mechanism of ligand selectivity and specific activation of the bradykinin receptor. These findings also provide a framework for guiding drug design targeting bradykinin receptors for the treatment of inflammation, cardiovascular disorders and COVID-19.


Subject(s)
Bradykinin/metabolism , COVID-19/pathology , Kallidin/metabolism , Receptors, Bradykinin/metabolism , Cryoelectron Microscopy , Enzyme Activation/physiology , Humans , Protein Structure, Tertiary , Pulmonary Edema/pathology , Pulmonary Edema/virology , SARS-CoV-2
12.
Acta Physiol (Oxf) ; 231(1): e13513, 2021 01.
Article in English | MEDLINE | ID: covidwho-1388186

ABSTRACT

The renin angiotensin system (RAS) plays an important role in the pathogenesis of variety of diseases. Targeting the formation and action of angiotensin II (Ang II), the main RAS peptide, has been the key therapeutic target for last three decades. ACE-related carboxypeptidase (ACE2), a monocarboxypeptidase that had been discovered 20 years ago, is one of the catalytically most potent enzymes known to degrade Ang II to Ang-(1-7), a peptide that is increasingly accepted to have organ-protective properties that oppose and counterbalance those of Ang II. In addition to its role as a RAS enzyme ACE2 is the main receptor for SARS-CoV-2. In this review, we discuss various strategies that have been used to achieve amplification of ACE2 activity including the potential therapeutic potential of soluble recombinant ACE2 protein and novel shorter ACE2 variants.


Subject(s)
Angiotensin-Converting Enzyme 2 , Antiviral Agents/therapeutic use , COVID-19/drug therapy , COVID-19/therapy , Genetic Therapy , Receptors, Virus , SARS-CoV-2/pathogenicity , Virus Internalization/drug effects , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Angiotensin-Converting Enzyme 2/therapeutic use , Animals , COVID-19/enzymology , COVID-19/genetics , COVID-19/virology , Enzyme Activation , Enzyme Activators/therapeutic use , Gene Amplification , Host-Pathogen Interactions , Humans , Receptors, Virus/genetics , Receptors, Virus/metabolism , Receptors, Virus/therapeutic use , Recombinant Proteins/therapeutic use
13.
Proc Natl Acad Sci U S A ; 118(36)2021 09 07.
Article in English | MEDLINE | ID: covidwho-1370748

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has killed more than 4 million humans globally, but there is no bona fide Food and Drug Administration-approved drug-like molecule to impede the COVID-19 pandemic. The sluggish pace of traditional therapeutic discovery is poorly suited to producing targeted treatments against rapidly evolving viruses. Here, we used an affinity-based screen of 4 billion DNA-encoded molecules en masse to identify a potent class of virus-specific inhibitors of the SARS-CoV-2 main protease (Mpro) without extensive and time-consuming medicinal chemistry. CDD-1714, the initial three-building-block screening hit (molecular weight [MW] = 542.5 g/mol), was a potent inhibitor (inhibition constant [K i] = 20 nM). CDD-1713, a smaller two-building-block analog (MW = 353.3 g/mol) of CDD-1714, is a reversible covalent inhibitor of Mpro (K i = 45 nM) that binds in the protease pocket, has specificity over human proteases, and shows in vitro efficacy in a SARS-CoV-2 infectivity model. Subsequently, key regions of CDD-1713 that were necessary for inhibitory activity were identified and a potent (K i = 37 nM), smaller (MW = 323.4 g/mol), and metabolically more stable analog (CDD-1976) was generated. Thus, screening of DNA-encoded chemical libraries can accelerate the discovery of efficacious drug-like inhibitors of emerging viral disease targets.


Subject(s)
Coronavirus 3C Proteases/antagonists & inhibitors , Coronavirus 3C Proteases/genetics , Drug Discovery/methods , Protease Inhibitors/chemistry , Protease Inhibitors/pharmacology , SARS-CoV-2/drug effects , SARS-CoV-2/genetics , Animals , COVID-19/drug therapy , COVID-19/virology , Cells, Cultured , Coronavirus 3C Proteases/metabolism , Dose-Response Relationship, Drug , Enzyme Activation , Genetic Engineering , Humans , Models, Molecular , Molecular Conformation , Molecular Structure , SARS-CoV-2/metabolism , Structure-Activity Relationship , Virus Replication
14.
Angew Chem Int Ed Engl ; 60(40): 21662-21667, 2021 09 27.
Article in English | MEDLINE | ID: covidwho-1363645

ABSTRACT

There is an urgent need to develop antiviral drugs and alleviate the current COVID-19 pandemic. Herein we report the design and construction of chimeric oligonucleotides comprising a 2'-OMe-modified antisense oligonucleotide and a 5'-phosphorylated 2'-5' poly(A)4 (4A2-5 ) to degrade envelope and spike RNAs of SARS-CoV-2. The oligonucleotide was used for searching and recognizing target viral RNA sequence, and the conjugated 4A2-5 was used for guided RNase L activation to sequence-specifically degrade viral RNAs. Since RNase L can potently cleave single-stranded RNA during innate antiviral response, degradation efficiencies with these chimeras were twice as much as those with only antisense oligonucleotides for both SARS-CoV-2 RNA targets. In pseudovirus infection models, chimera-S4 achieved potent and broad-spectrum inhibition of SARS-CoV-2 and its N501Y and/or ΔH69/ΔV70 mutants, indicating a promising antiviral agent based on the nucleic acid-hydrolysis targeting chimera (NATAC) strategy.


Subject(s)
Antiviral Agents/pharmacology , Endoribonucleases/metabolism , Enzyme Activation/drug effects , Oligonucleotides, Antisense/pharmacology , SARS-CoV-2/drug effects , Animals , Chlorocebus aethiops , Coronavirus Envelope Proteins/genetics , Drug Design , HEK293 Cells , Humans , Hydrolysis/drug effects , Microbial Sensitivity Tests , Mutation , RNA, Viral/metabolism , Spike Glycoprotein, Coronavirus/genetics , Vero Cells
15.
Cell Syst ; 12(8): 780-794.e7, 2021 08 18.
Article in English | MEDLINE | ID: covidwho-1267622

ABSTRACT

COVID-19 is highly variable in its clinical presentation, ranging from asymptomatic infection to severe organ damage and death. We characterized the time-dependent progression of the disease in 139 COVID-19 inpatients by measuring 86 accredited diagnostic parameters, such as blood cell counts and enzyme activities, as well as untargeted plasma proteomes at 687 sampling points. We report an initial spike in a systemic inflammatory response, which is gradually alleviated and followed by a protein signature indicative of tissue repair, metabolic reconstitution, and immunomodulation. We identify prognostic marker signatures for devising risk-adapted treatment strategies and use machine learning to classify therapeutic needs. We show that the machine learning models based on the proteome are transferable to an independent cohort. Our study presents a map linking routinely used clinical diagnostic parameters to plasma proteomes and their dynamics in an infectious disease.


Subject(s)
Biomarkers/analysis , COVID-19/pathology , Disease Progression , Proteome/physiology , Age Factors , Blood Cell Count , Blood Gas Analysis , Enzyme Activation , Humans , Inflammation/pathology , Machine Learning , Prognosis , Proteomics , SARS-CoV-2/immunology
16.
Blood ; 138(4): 344-349, 2021 07 29.
Article in English | MEDLINE | ID: covidwho-1255893

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection is associated with the hypercoagulable state. Tissue factor (TF) is the primary cellular initiator of coagulation. Most of the TF expressed on cell surfaces remains cryptic. Sphingomyelin (SM) is responsible for maintaining TF in the encrypted state, and hydrolysis of SM by acid sphingomyelinase (ASMase) increases TF activity. ASMase was shown to play a role in virus infection biology. In the present study, we investigated the role of ASMase in SARS-CoV-2 infection-induced TF procoagulant activity. Infection of human monocyte-derived macrophages (MDMs) with SARS-CoV-2 spike protein pseudovirus (SARS-CoV-2-SP-PV) markedly increased TF procoagulant activity at the cell surface and released TF+ extracellular vesicles. The pseudovirus infection did not increase either TF protein expression or phosphatidylserine externalization. SARS-CoV-2-SP-PV infection induced the translocation of ASMase to the outer leaflet of the plasma membrane, which led to the hydrolysis of SM in the membrane. Pharmacologic inhibitors or genetic silencing of ASMase attenuated SARS-CoV-2-SP-PV-induced increased TF activity. Inhibition of the SARS-CoV-2 receptor, angiotensin-converting enzyme-2, attenuated SARS-CoV-2-SP-PV-induced increased TF activity. Overall, our data suggest that SARS-CoV-2 infection activates the coagulation by decrypting TF through activation of ASMase. Our data suggest that the US Food and Drug Administration-approved functional inhibitors of ASMase may help treat hypercoagulability in patients with COVID-19.


Subject(s)
COVID-19/blood , Macrophages/virology , Membrane Proteins/physiology , SARS-CoV-2 , Sphingomyelin Phosphodiesterase/physiology , Spike Glycoprotein, Coronavirus/physiology , Thrombophilia/etiology , Thromboplastin/physiology , Angiotensin-Converting Enzyme 2/physiology , COVID-19/complications , Cell-Derived Microparticles , Enzyme Activation , Humans , Hydrolysis , Macrophages/enzymology , Molecular Targeted Therapy , Plasmids , Protein Transport , RNA Interference , RNA, Small Interfering/genetics , Receptors, Virus/physiology , Sphingomyelin Phosphodiesterase/antagonists & inhibitors , Sphingomyelins/physiology , Thrombophilia/blood , Thrombophilia/drug therapy , Thrombophilia/enzymology
17.
Vascul Pharmacol ; 139: 106879, 2021 08.
Article in English | MEDLINE | ID: covidwho-1243242

ABSTRACT

Toll-like receptor 4 (TLR4) contributes to the pathophysiology of diabetes. This happens, at least in part, because TLR4 modulates the enzyme NADPH oxidase, a primary source of ROS in vascular structures. Increased oxidative stress disrupts key vascular signaling mechanisms and drives the progression of diabetes, elevating the likelihood of cardiovascular diseases. Recently, it has been shown that patients with diabetes are also at a higher risk of developing severe coronavirus disease 2019 (COVID-19). Given the importance of the interaction between TLR4 and NADPH oxidase to the disrupted diabetic vascular system, we put forward the hypothesis that TLR4-mediated NADPH oxidase-derived ROS might be a critical mechanism to help explain why this disparity appears in diabetic patients, but unfortunately, conclusive experimental evidence still lacks in the literature. Herein, we focus on discussing the pathological implications of this signaling communication in the diabetic vasculature and exploring this crosstalk in the context of diabetes-associated severe COVID-19.


Subject(s)
Blood Vessels/enzymology , COVID-19/virology , Diabetes Mellitus/enzymology , Diabetic Angiopathies/enzymology , NADPH Oxidases/metabolism , SARS-CoV-2/pathogenicity , Toll-Like Receptor 4/metabolism , Animals , Blood Vessels/physiopathology , Blood Vessels/virology , COVID-19/enzymology , COVID-19/physiopathology , Diabetes Mellitus/physiopathology , Diabetic Angiopathies/physiopathology , Enzyme Activation , Host-Pathogen Interactions , Humans , Oxidative Stress , Prognosis , Reactive Oxygen Species/metabolism , Signal Transduction
18.
Sci Immunol ; 6(59)2021 05 18.
Article in English | MEDLINE | ID: covidwho-1234281

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has caused a global pandemic, resulting millions of infections and deaths with few effective interventions available. Here, we demonstrate that SARS-CoV-2 evades interferon (IFN) activation in respiratory epithelial cells, resulting in a delayed response in bystander cells. Since pretreatment with IFNs can block viral infection, we reasoned that pharmacological activation of innate immune pathways could control SARS-CoV-2 infection. To identify potent antiviral innate immune agonists, we screened a panel of 75 microbial ligands that activate diverse signaling pathways and identified cyclic dinucleotides (CDNs), canonical STING agonists, as antiviral. Since CDNs have poor bioavailability, we tested the small molecule STING agonist diABZI, and found that it potently inhibits SARS-CoV-2 infection of diverse strains including variants of concern (B.1.351) by transiently stimulating IFN signaling. Importantly, diABZI restricts viral replication in primary human bronchial epithelial cells and in mice in vivo. Our study provides evidence that activation of STING may represent a promising therapeutic strategy to control SARS-CoV-2.


Subject(s)
Antiviral Agents/pharmacology , Benzimidazoles/pharmacology , COVID-19/prevention & control , Interferons/immunology , Membrane Proteins/agonists , Animals , Cell Line , Chlorocebus aethiops , Enzyme Activation/drug effects , Epithelial Cells/virology , Humans , Immune Evasion/immunology , Immunity, Innate/drug effects , Immunity, Innate/immunology , Mice , Mice, Inbred C57BL , Mice, Transgenic , SARS-CoV-2/growth & development , SARS-CoV-2/immunology , Vero Cells , Virus Replication/drug effects
19.
Sci Immunol ; 6(59)2021 05 18.
Article in English | MEDLINE | ID: covidwho-1234280

ABSTRACT

Coronaviruses are a family of RNA viruses that cause acute and chronic diseases of the upper and lower respiratory tract in humans and other animals. SARS-CoV-2 is a recently emerged coronavirus that has led to a global pandemic causing a severe respiratory disease known as COVID-19 with significant morbidity and mortality worldwide. The development of antiviral therapeutics are urgently needed while vaccine programs roll out worldwide. Here we describe a diamidobenzimidazole compound, diABZI-4, that activates STING and is highly effective in limiting SARS-CoV-2 replication in cells and animals. diABZI-4 inhibited SARS-CoV-2 replication in lung epithelial cells. Administration of diABZI-4 intranasally before or even after virus infection conferred complete protection from severe respiratory disease in K18-ACE2-transgenic mice infected with SARS-CoV-2. Intranasal delivery of diABZI-4 induced a rapid short-lived activation of STING, leading to transient proinflammatory cytokine production and lymphocyte activation in the lung associated with inhibition of viral replication. Our study supports the use of diABZI-4 as a host-directed therapy which mobilizes antiviral defenses for the treatment and prevention of COVID-19.


Subject(s)
Antiviral Agents/pharmacology , Benzimidazoles/pharmacology , COVID-19/drug therapy , COVID-19/prevention & control , Membrane Proteins/agonists , SARS-CoV-2/drug effects , A549 Cells , Animals , CD8-Positive T-Lymphocytes/immunology , Cell Line , Chlorocebus aethiops , Enzyme Activation/drug effects , Epithelial Cells/virology , Female , Humans , Killer Cells, Natural/immunology , Lymphocyte Activation/drug effects , Male , Membrane Proteins/metabolism , Mice , Mice, Knockout , SARS-CoV-2/growth & development , Vero Cells , Virus Replication/drug effects
20.
Protein Expr Purif ; 185: 105894, 2021 09.
Article in English | MEDLINE | ID: covidwho-1209890

ABSTRACT

The novel Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2 or COVID-19) has led to a world-wild pandemic. The replication of SARS-CoV-2 RNA genome involves the core replication-transcription complex (RTC, nsp12-nsp7-nsp8) and the proofreading complex (nsp14-nsp10) that can correct mismatched base pairs during replication. Structures and functions of SARS-CoV-2 RTC have been actively studied, yet little is known about SARS-CoV-2 nsp14-nsp10. Here, we purified, reconstituted, and characterized the SARS-CoV-2 nsp14-nsp10 proofreading nuclease in vitro. We show that SARS-CoV-2 nsp14 is activated by nsp10, functioning as a potent RNase that can hydrolyze RNAs in the context of single- and double-stranded RNA and RNA/DNA hybrid duplex. SARS-CoV-2 nsp14-nsp10 shows a metal-dependent nuclease activity but has different metal selectivity from RTC. While RTC is activated by Ca2+, nsp14-nsp10 is completely inhibited. Importantly, the reconstituted SARS-CoV-2 nsp14-nsp10 efficiently removed the A:A mismatch at the 3'-end of the primer, enabling the stalled RTC to restart RNA replication. Our collective results confirm that SARS-CoV-2 nsp14-nsp10 functions as the RNA proofreading complex in SARS-CoV-2 replication and provide a useful foundation to understand the structure and function of SARS-CoV-2 RNA metabolism.


Subject(s)
COVID-19/virology , Exoribonucleases/metabolism , RNA, Viral/metabolism , SARS-CoV-2/metabolism , Viral Nonstructural Proteins/metabolism , Viral Regulatory and Accessory Proteins/metabolism , Calcium/metabolism , Enzyme Activation , Humans , Hydrolysis , Substrate Specificity
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