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1.
Nat Commun ; 12(1): 3433, 2021 06 08.
Article in English | MEDLINE | ID: covidwho-1261998

ABSTRACT

The COVID-19 pandemic, caused by the SARS-CoV-2 virus, has created global health and economic emergencies. SARS-CoV-2 viruses promote their own spread and virulence by hijacking human proteins, which occurs through viral protein recognition of human targets. To understand the structural basis for SARS-CoV-2 viral-host protein recognition, here we use cryo-electron microscopy (cryo-EM) to determine a complex structure of the human cell junction protein PALS1 and SARS-CoV-2 viral envelope (E) protein. Our reported structure shows that the E protein C-terminal DLLV motif recognizes a pocket formed exclusively by hydrophobic residues from the PDZ and SH3 domains of PALS1. Our structural analysis provides an explanation for the observation that the viral E protein recruits PALS1 from lung epithelial cell junctions. In addition, our structure provides novel targets for peptide- and small-molecule inhibitors that could block the PALS1-E interactions to reduce E-mediated virulence.


Subject(s)
Coronavirus Envelope Proteins/chemistry , Coronavirus Envelope Proteins/metabolism , Intercellular Junctions/metabolism , Membrane Proteins/metabolism , Nucleoside-Phosphate Kinase/metabolism , Amino Acid Sequence , Coronavirus Envelope Proteins/ultrastructure , Cryoelectron Microscopy , Humans , Protein Domains , SARS-CoV-2/physiology , Structural Homology, Protein , Structure-Activity Relationship
2.
Int J Biol Macromol ; 183: 1753-1773, 2021 Jul 31.
Article in English | MEDLINE | ID: covidwho-1243010

ABSTRACT

The deficiency of chemical-synthesized antiviral drugs when applied in clinical therapy, such as drug resistance, and the lack of effective antiviral drugs to treat some newly emerging virus infections, such as COVID-19, promote the demand of novelty and safety anti-virus drug candidate from natural functional ingredient. Numerous studies have shown that some polysaccharides sourcing from edible and medicinal fungus (EMFs) exert direct or indirect anti-viral capacities. However, the internal connection of fungus type, polysaccharides structural characteristics, action mechanism was still unclear. Herein, our review focus on the two aspects, on the one hand, we discussed the type of anti-viral EMFs and the structural characteristics of polysaccharides to clarify the structure-activity relationship, on the other hand, the directly or indirectly antiviral mechanism of EMFs polysaccharides, including virus function suppression, immune-modulatory activity, anti-inflammatory activity, regulation of population balance of gut microbiota have been concluded to provide a comprehensive theory basis for better clinical utilization of EMFs polysaccharides as anti-viral agents.


Subject(s)
Agaricales/chemistry , Anti-Inflammatory Agents , Antiviral Agents , COVID-19/drug therapy , Fungal Polysaccharides , Immunologic Factors , SARS-CoV-2/immunology , Anti-Inflammatory Agents/chemistry , Anti-Inflammatory Agents/classification , Anti-Inflammatory Agents/therapeutic use , Antiviral Agents/chemistry , Antiviral Agents/classification , Antiviral Agents/therapeutic use , COVID-19/immunology , COVID-19/prevention & control , Fungal Polysaccharides/chemistry , Fungal Polysaccharides/classification , Fungal Polysaccharides/therapeutic use , Gastrointestinal Microbiome/drug effects , Gastrointestinal Microbiome/immunology , Humans , Immunologic Factors/chemistry , Immunologic Factors/classification , Immunologic Factors/therapeutic use
3.
Am J Psychiatry ; 178(6): 530-540, 2021 06.
Article in English | MEDLINE | ID: covidwho-1201589

ABSTRACT

OBJECTIVE: Increased anxiety in response to the COVID-19 pandemic has been widely noted. The purpose of this study was to test whether the prepandemic functional connectome predicted individual anxiety induced by the pandemic. METHODS: Anxiety scores from healthy undergraduate students were collected during the severe and remission periods of the pandemic (first survey, February 22-28, 2020, N=589; second survey, April 24 to May 1, 2020, N=486). Brain imaging data and baseline (daily) anxiety ratings were acquired before the pandemic. The predictive performance of the functional connectome on individual anxiety was examined using machine learning and was validated in two external undergraduate student samples (N=149 and N=474). The clinical relevance of the findings was further explored by applying the connectome-based neuromarkers of pandemic-related anxiety to distinguish between individuals with specific mental disorders and matched healthy control subjects (generalized anxiety disorder, N=43; major depression, N=536; schizophrenia, N=72). RESULTS: Anxiety scores increased from the prepandemic baseline to the severe stage of the pandemic and remained high in the remission stage. The prepandemic functional connectome predicted pandemic-related anxiety and generalized to the external sample but showed poor performance for predicting daily anxiety. The connectome-based neuromarkers of pandemic-related anxiety further distinguished between participants with generalized anxiety and healthy control subjects but were not useful for diagnostic classification in major depression and schizophrenia. CONCLUSIONS: These findings demonstrate the feasibility of using the functional connectome to predict individual anxiety induced by major stressful events (e.g., the current global health crisis), which advances our understanding of the neurobiological basis of anxiety susceptibility and may have implications for developing targeted psychological and clinical interventions that promote the reduction of stress and anxiety.


Subject(s)
Anxiety/etiology , COVID-19/psychology , Connectome , Adult , Anxiety/diagnosis , Biomarkers , Cohort Studies , Feasibility Studies , Female , Functional Neuroimaging , Humans , Longitudinal Studies , Male , Pandemics , Predictive Value of Tests , Young Adult
4.
J Immunol Res ; 2021: 6659410, 2021.
Article in English | MEDLINE | ID: covidwho-1140376

ABSTRACT

The main basis for hydroxychloroquine (HCQ) treatment in COVID-19 is the compound's ability to inhibit viral replication in vitro. HCQ also suppresses immunity, mainly by interference in TLR signalling, but reliable clinical data on the extent and nature of HCQ-induced immunosuppression are lacking. Here, we discuss the mechanistic basis for the use of HCQ against SARS-CoV-2 in a prophylactic setting and in a therapeutic setting, at different stages of the disease. We argue that the clinical effect of prophylactic or therapeutic HCQ treatment in COVID-19 depends on the balance between inhibition of viral replication, immunosuppression, and off-target side effects, and that the outcome is probably dependent on disease stage and disease severity. This is supported by the initial outcomes of the well-designed randomized controlled trials: so far, evidence for a beneficial effect of HCQ treatment for COVID-19 is weak and conflicting.


Subject(s)
Antiviral Agents/therapeutic use , COVID-19/drug therapy , Hydroxychloroquine/therapeutic use , Humans , SARS-CoV-2/drug effects , SARS-CoV-2/immunology , Severity of Illness Index , Signal Transduction/drug effects , Treatment Outcome , Virus Replication/drug effects
5.
Eur J Public Health ; 31(3): 619-624, 2021 07 13.
Article in English | MEDLINE | ID: covidwho-1123256

ABSTRACT

BACKGROUND: In responding to Covid-19, governments have tried to balance protecting health while minimizing gross domestic product (GDP) losses. We compare health-related net benefit (HRNB) and GDP losses associated with government responses of the UK, Ireland, Germany, Spain and Sweden from UK healthcare payer perspective. METHODS: We compared observed cases, hospitalizations and deaths under 'mitigation' to modelled events under 'no mitigation' to 20 July 2020. We thus calculated healthcare costs, quality adjusted life years (QALYs), and HRNB at £20,000/QALY saved by each country. On per population (i.e. per capita) basis, we compared HRNB with forecast reductions in 2020 GDP growth (overall or compared with Sweden as minimal mitigation country) and qualitatively and quantitatively described government responses. RESULTS: The UK saved 3.17 (0.32-3.65) million QALYs, £33 (8-38) billion healthcare costs and £1416 (220-1637) HRNB per capita at £20,000/QALY. Per capita, this is comparable to £1455 GDP loss using Sweden as comparator and offsets 46.1 (7.1-53.2)% of total £3075 GDP loss. Germany, Spain, and Sweden had greater HRNB per capita. These also offset a greater percentage of total GDP losses per capita. Ireland fared worst on both measures. Countries with more mask wearing, testing, and population susceptibility had better outcomes. Highest stringency responses did not appear to have best outcomes. CONCLUSIONS: Our exploratory analysis indicates the benefit of government Covid-19 responses may outweigh their economic costs. The extent that HRNB offset economic losses appears to relate to population characteristics, testing levels, and mask wearing, rather than response stringency.


Subject(s)
COVID-19 , Cost-Benefit Analysis , Europe , Germany , Health Care Costs , Humans , Ireland , SARS-CoV-2 , Spain , Sweden , United Kingdom
6.
Viruses ; 13(2)2021 02 17.
Article in English | MEDLINE | ID: covidwho-1122299

ABSTRACT

MASP-2, mannose-binding protein-associated serine protease 2, is a key enzyme in the lectin pathway of complement activation. Hyperactivation of this protein by human coronaviruses SARS-CoV, MERS-CoV and SARS-CoV-2 has been found to contribute to aberrant complement activation in patients, leading to aggravated lung injury with potentially fatal consequences. This hyperactivation is triggered in the lungs through a conserved, direct interaction between MASP-2 and coronavirus nucleocapsid (N) proteins. Blocking this interaction with monoclonal antibodies and interfering directly with the catalytic activity of MASP-2, have been found to alleviate coronavirus-induced lung injury both in vitro and in vivo. In this study, a virtual library of 8736 licensed drugs and clinical agents has been screened in silico according to two parallel strategies. The first strategy aims at identifying direct inhibitors of MASP-2 catalytic activity, while the second strategy focusses on finding protein-protein interaction inhibitors (PPIs) of MASP-2 and coronaviral N proteins. Such agents could represent promising support treatment options to prevent lung injury and reduce mortality rates of infections caused by both present and future-emerging coronaviruses. Forty-six drug repurposing candidates were purchased and, for the ones selected as potential direct inhibitors of MASP-2, a preliminary in vitro assay was conducted to assess their interference with the lectin pathway of complement activation. Some of the tested agents displayed a dose-response inhibitory activity of the lectin pathway, potentially providing the basis for a viable support strategy to prevent the severe complications of coronavirus infections.


Subject(s)
Coronavirus Nucleocapsid Proteins , Enzyme Inhibitors/chemistry , Mannose-Binding Protein-Associated Serine Proteases/metabolism , Protein Binding/drug effects , Coronavirus Infections/drug therapy , Coronavirus Nucleocapsid Proteins/antagonists & inhibitors , Coronavirus Nucleocapsid Proteins/metabolism , Drug Repositioning , Humans , Structure-Activity Relationship
7.
Innovation (N Y) ; 2(1): 100080, 2021 Feb 28.
Article in English | MEDLINE | ID: covidwho-1033608

ABSTRACT

The outbreak of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has developed into an unprecedented global pandemic. Nucleoside analogs, such as Remdesivir and Favipiravir, can serve as the first-line broad-spectrum antiviral drugs by targeting the viral polymerases. However, the underlying mechanisms for the antiviral efficacies of these drugs are far from well understood. Here, we reveal that Favipiravir, as a pyrazine derivative, could be incorporated into the viral RNA products by mimicking both adenine and guanine nucleotides. This drug thus inhibits viral replication mainly by inducing mutations in progeny RNAs, different from Remdesivir or other RNA-terminating nucleoside analogs that impair the elongation of RNA products. We further determined the cryo-EM structure of Favipiravir bound to the replicating polymerase complex of SARS-CoV-2 in the pre-catalytic state. This structure provides a missing snapshot for visualizing the catalysis dynamics of coronavirus polymerase, and reveals an unexpected base-pairing pattern between Favipiravir and pyrimidine residues that may explain its capacity for mimicking both adenine and guanine nucleotides. These findings shed light on the mechanism of coronavirus polymerase catalysis and provide a rational basis for developing antiviral drugs to combat the SARS-CoV-2 pandemic.

8.
Am J Cancer Res ; 10(8): 2535-2545, 2020.
Article in English | MEDLINE | ID: covidwho-754993

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic, caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) or 2019 novel coronavirus (2019-nCoV), took tens of thousands of lives and caused tremendous economic losses. The main protease (Mpro) of SARS-CoV-2 is a potential target for treatment of COVID-19 due to its critical role in maturation of viral proteins and subsequent viral replication. Conceptually and technically, targeting therapy against Mpro is similar to target therapy to treat cancer. Previous studies show that GC376, a broad-spectrum dipeptidyl Mpro inhibitor, efficiently blocks the proliferation of many animal and human coronaviruses including SARS-CoV, Middle East respiratory syndrome coronavirus (MERS-CoV), porcine epidemic diarrhea virus (PEDV), and feline infectious peritonitis virus (FIPV). Due to the conservation of structure and catalytic mechanism of coronavirus main protease, repurposition of GC376 against SARS-CoV-2 may be an effective way for the treatment of COVID-19 in humans. To validate this conjecture, the binding affinity and IC50 value of Mpro with GC376 was determined by isothermal titration calorimetry (ITC) and fluorescence resonance energy transfer (FRET) assay, respectively. The results showed that GC376 binds to SARS-CoV-2 Mpro tightly (KD = 1.6 µM) and efficiently inhibit its proteolytic activity (IC50 = 0.89 µM). We also elucidate the high-resolution structure of dimeric SARS-CoV-2 Mpro in complex with GC376. The cocrystal structure showed that GC376 and the catalytic Cys145 of Mpro covalently linked through forming a hemithioacetal group and releasing a sulfonic acid group. Because GC376 is already known as a broad-spectrum antiviral medication and successfully used in animal, it will be a suitable candidate for anti-COVID-19 treatment.

9.
Essays Biochem ; 64(3): 443-462, 2020 09 23.
Article in English | MEDLINE | ID: covidwho-744387

ABSTRACT

Today, persistent and uncontrolled inflammation is appreciated to play a pivotal role in many diseases, such as cardiovascular diseases, neurodegenerative diseases, metabolic syndrome and many other diseases of public health concern (e.g. Coronavirus Disease 2019 (COVID-19) and periodontal disease). The ideal response to initial challenge in humans is a self-limited inflammatory response leading to complete resolution. The resolution phase is now widely recognized as a biosynthetically active process, governed by a superfamily of endogenous chemical mediators that stimulate resolution of inflammatory responses, namely specialized proresolving mediators (SPMs). Because resolution is the natural ideal response, the SPMs have gained attention. SPMs are mediators that include ω-6 arachidonic acid-derived lipoxins, ω-3 eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA)-derived resolvins, protectins and maresins, cysteinyl-SPMs, as well as n-3 docosapentaenoic acid (DPA)-derived SPMs. These novel immunoresolvents, their biosynthetic pathways and receptors have proven to promote resolution of inflammation, clearance of microbes, reduce pain and promote tissue regeneration via specific cellular and molecular mechanisms. As of 17 August, 2020, PubMed.gov reported >1170 publications for resolvins, confirming their potent protective actions from many laboratories worldwide. Since this field is rapidly expanding, we provide a short update of advances within 2-3 years from human and preclinical animal studies, together with the structural-functional elucidation of SPMs and identification of novel SPM receptors. These new discoveries indicate that SPMs, their pathways and receptors could provide a basis for new approaches for treating inflammation-associated diseases and for stimulating tissue regeneration via resolution pharmacology and precision nutrition.


Subject(s)
Betacoronavirus/immunology , Coronavirus Infections/immunology , Coronavirus Infections/virology , Inflammation Mediators/immunology , Inflammation Mediators/metabolism , Inflammation/immunology , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Animals , COVID-19 , Coronavirus Infections/epidemiology , Coronavirus Infections/metabolism , Docosahexaenoic Acids/immunology , Docosahexaenoic Acids/metabolism , Humans , Inflammation/metabolism , Pandemics , Pneumonia, Viral/epidemiology , Pneumonia, Viral/metabolism , SARS-CoV-2
10.
Biomol NMR Assign ; 14(2): 339-346, 2020 10.
Article in English | MEDLINE | ID: covidwho-716391

ABSTRACT

The SARS-CoV-2 genome encodes for approximately 30 proteins. Within the international project COVID19-NMR, we distribute the spectroscopic analysis of the viral proteins and RNA. Here, we report NMR chemical shift assignments for the protein Nsp3b, a domain of Nsp3. The 217-kDa large Nsp3 protein contains multiple structurally independent, yet functionally related domains including the viral papain-like protease and Nsp3b, a macrodomain (MD). In general, the MDs of SARS-CoV and MERS-CoV were suggested to play a key role in viral replication by modulating the immune response of the host. The MDs are structurally conserved. They most likely remove ADP-ribose, a common posttranslational modification, from protein side chains. This de-ADP ribosylating function has potentially evolved to protect the virus from the anti-viral ADP-ribosylation catalyzed by poly-ADP-ribose polymerases (PARPs), which in turn are triggered by pathogen-associated sensing of the host immune system. This renders the SARS-CoV-2 Nsp3b a highly relevant drug target in the viral replication process. We here report the near-complete NMR backbone resonance assignment (1H, 13C, 15N) of the putative Nsp3b MD in its apo form and in complex with ADP-ribose. Furthermore, we derive the secondary structure of Nsp3b in solution. In addition, 15N-relaxation data suggest an ordered, rigid core of the MD structure. These data will provide a basis for NMR investigations targeted at obtaining small-molecule inhibitors interfering with the catalytic activity of Nsp3b.


Subject(s)
Adenosine Diphosphate Ribose/metabolism , Apoproteins/chemistry , Betacoronavirus/metabolism , Carbon-13 Magnetic Resonance Spectroscopy , Nitrogen Isotopes/chemistry , Proton Magnetic Resonance Spectroscopy , Viral Nonstructural Proteins/chemistry , Amino Acid Sequence , Apoproteins/metabolism , Protein Domains , Protein Structure, Secondary , SARS-CoV-2 , Viral Nonstructural Proteins/metabolism
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