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1.
Stem Cell Reports ; 17(2): 307-320, 2022 02 08.
Article in English | MEDLINE | ID: covidwho-1712991

ABSTRACT

Neurological complications are common in COVID-19. Although SARS-CoV-2 has been detected in patients' brain tissues, its entry routes and resulting consequences are not well understood. Here, we show a pronounced upregulation of interferon signaling pathways of the neurovascular unit in fatal COVID-19. By investigating the susceptibility of human induced pluripotent stem cell (hiPSC)-derived brain capillary endothelial-like cells (BCECs) to SARS-CoV-2 infection, we found that BCECs were infected and recapitulated transcriptional changes detected in vivo. While BCECs were not compromised in their paracellular tightness, we found SARS-CoV-2 in the basolateral compartment in transwell assays after apical infection, suggesting active replication and transcellular transport of virus across the blood-brain barrier (BBB) in vitro. Moreover, entry of SARS-CoV-2 into BCECs could be reduced by anti-spike-, anti-angiotensin-converting enzyme 2 (ACE2)-, and anti-neuropilin-1 (NRP1)-specific antibodies or the transmembrane protease serine subtype 2 (TMPRSS2) inhibitor nafamostat. Together, our data provide strong support for SARS-CoV-2 brain entry across the BBB resulting in increased interferon signaling.


Subject(s)
Blood-Brain Barrier/virology , Central Nervous System/virology , SARS-CoV-2/physiology , Virus Internalization , Antibodies/pharmacology , Benzamidines/pharmacology , COVID-19/pathology , COVID-19/virology , Endothelial Cells/cytology , Endothelial Cells/metabolism , Endothelial Cells/virology , Guanidines/pharmacology , Humans , Induced Pluripotent Stem Cells/cytology , Induced Pluripotent Stem Cells/metabolism , Models, Biological , RNA, Viral/metabolism , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification , Virus Internalization/drug effects
2.
Viruses ; 14(2)2022 02 14.
Article in English | MEDLINE | ID: covidwho-1687055

ABSTRACT

Inhibition of transmembrane serine protease 2 (TMPRSS2) is expected to block the spike protein-mediated fusion of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). Nafamostat, a potent TMPRSS2 inhibitor as well as a candidate for anti-SARS-CoV-2 drug, possesses the same acyl substructure as camostat, but is known to have a greater antiviral effect. A unique aspect of the molecular binding of nafamostat has been recently reported to be the formation of a covalent bond between its acyl substructure and Ser441 in TMPRSS2. In this study, we investigated crucial elements that cause the difference in anti-SARS-CoV-2 activity of nafamostat and camostat. In silico analysis showed that Asp435 significantly contributes to the binding of nafamostat and camostat to TMPRSS2, while Glu299 interacts strongly only with nafamostat. The estimated binding affinity for each compound with TMPRSS2 was actually consistent with the higher activity of nafamostat; however, the evaluation of the newly synthesized nafamostat derivatives revealed that the predicted binding affinity did not correlate with their anti-SARS-CoV-2 activity measured by the cytopathic effect (CPE) inhibition assay. It was further shown that the substitution of the ester bond with amide bond in nafamostat resulted in significantly weakened anti-SARS-CoV-2 activity. These results strongly indicate that the ease of covalent bond formation with Ser441 in TMPRSS2 possibly plays a major role in the anti-SARS-CoV-2 effect of nafamostat and its derivatives.


Subject(s)
Antiviral Agents/pharmacology , Benzamidines/pharmacology , Computer Simulation , Guanidines/pharmacology , Protease Inhibitors/pharmacology , SARS-CoV-2/drug effects , Benzamidines/chemistry , COVID-19/drug therapy , Cell Line , Guanidines/chemistry , Humans , Molecular Dynamics Simulation , Protease Inhibitors/chemistry , Serine Endopeptidases/metabolism , Virus Internalization/drug effects
3.
J Neuroinflammation ; 19(1): 8, 2022 Jan 06.
Article in English | MEDLINE | ID: covidwho-1613238

ABSTRACT

BACKGROUND: The serine protease inhibitor nafamostat has been proposed as a treatment for COVID-19, by inhibiting TMPRSS2-mediated viral cell entry. Nafamostat has been shown to have other, immunomodulatory effects, which may be beneficial for treatment, however animal models of ssRNA virus infection are lacking. In this study, we examined the potential of the dual TLR7/8 agonist R848 to mimic the host response to an ssRNA virus infection and the associated behavioural response. In addition, we evaluated the anti-inflammatory effects of nafamostat in this model. METHODS: CD-1 mice received an intraperitoneal injection of R848 (200 µg, prepared in DMSO, diluted 1:10 in saline) or diluted DMSO alone, and an intravenous injection of either nafamostat (100 µL, 3 mg/kg in 5% dextrose) or 5% dextrose alone. Sickness behaviour was determined by temperature, food intake, sucrose preference test, open field and forced swim test. Blood and fresh liver, lung and brain were collected 6 h post-challenge to measure markers of peripheral and central inflammation by blood analysis, immunohistochemistry and qPCR. RESULTS: R848 induced a robust inflammatory response, as evidenced by increased expression of TNF, IFN-γ, CXCL1 and CXCL10 in the liver, lung and brain, as well as a sickness behaviour phenotype. Exogenous administration of nafamostat suppressed the hepatic inflammatory response, significantly reducing TNF and IFN-γ expression, but had no effect on lung or brain cytokine production. R848 administration depleted circulating leukocytes, which was restored by nafamostat treatment. CONCLUSIONS: Our data indicate that R848 administration provides a useful model of ssRNA virus infection, which induces inflammation in the periphery and CNS, and virus infection-like illness. In turn, we show that nafamostat has a systemic anti-inflammatory effect in the presence of the TLR7/8 agonist. Therefore, the results indicate that nafamostat has anti-inflammatory actions, beyond its ability to inhibit TMPRSS2, that might potentiate its anti-viral actions in pathologies such as COVID-19.


Subject(s)
Benzamidines , Guanidines , Inflammation/drug therapy , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors , Toll-Like Receptor 7/immunology , Virus Diseases/drug therapy , Animals , Benzamidines/pharmacology , Benzamidines/therapeutic use , COVID-19/complications , COVID-19/drug therapy , Guanidines/pharmacology , Guanidines/therapeutic use , Illness Behavior/drug effects , Imidazoles/administration & dosage , Imidazoles/immunology , Inflammation/metabolism , Inflammation/virology , Male , Mice , Serine Proteinase Inhibitors/pharmacology , Serine Proteinase Inhibitors/therapeutic use , Toll-Like Receptor 7/agonists , Virus Diseases/metabolism , Virus Diseases/virology
4.
Viruses ; 13(9)2021 09 04.
Article in English | MEDLINE | ID: covidwho-1478110

ABSTRACT

SARS-CoV-2 and its vaccine/immune-escaping variants continue to pose a serious threat to public health due to a paucity of effective, rapidly deployable, and widely available treatments. Here, we address these challenges by combining Pegasys (IFNα) and nafamostat to effectively suppress SARS-CoV-2 infection in cell culture and hamsters. Our results indicate that Serpin E1 is an important mediator of the antiviral activity of IFNα and that both Serpin E1 and nafamostat can target the same cellular factor TMPRSS2, which plays a critical role in viral replication. The low doses of the drugs in combination may have several clinical advantages, including fewer adverse events and improved patient outcome. Thus, our study may provide a proactive solution for the ongoing pandemic and potential future coronavirus outbreaks, which is still urgently required in many parts of the world.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Benzamidines/pharmacology , COVID-19/metabolism , COVID-19/virology , Guanidines/pharmacology , Interferon-alpha/pharmacology , SARS-CoV-2/drug effects , Serine Endopeptidases/metabolism , Animals , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Benzamidines/therapeutic use , COVID-19/drug therapy , Cricetinae , Disease Models, Animal , Drug Therapy, Combination , Female , Guanidines/therapeutic use , Host-Pathogen Interactions/drug effects , Humans , Interferon-alpha/therapeutic use , Virus Replication/drug effects
5.
Microbiol Spectr ; 9(2): e0025721, 2021 10 31.
Article in English | MEDLINE | ID: covidwho-1410327

ABSTRACT

Human-to-human transmission of viruses, such as influenza viruses and coronaviruses, can promote virus evolution and the emergence of new strains with increased potential for creating pandemics. Clinical studies analyzing how a particular type of virus progressively evolves new traits, such as resistance to antiviral therapies, as a result of passing between different human hosts are difficult to carry out because of the complexity, scale, and cost of the challenge. Here, we demonstrate that spontaneous evolution of influenza A virus through both mutation and gene reassortment can be reconstituted in vitro by sequentially passaging infected mucus droplets between multiple human lung airway-on-a-chip microfluidic culture devices (airway chips). Modeling human-to-human transmission of influenza virus infection on chips in the continued presence of the antiviral drugs amantadine or oseltamivir led to the spontaneous emergence of clinically prevalent resistance mutations, and strains that were resistant to both drugs were identified when they were administered in combination. In contrast, we found that nafamostat, an inhibitor targeting host serine proteases, did not induce viral resistance. This human preclinical model may be useful for studying viral evolution in vitro and identifying potential influenza virus variants before they appear in human populations, thereby enabling preemptive design of new and more effective vaccines and therapeutics. IMPORTANCE The rapid evolution of viruses, such as influenza viruses and severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), is challenging the use and development of antivirals and vaccines. Studies of within-host viral evolution can contribute to our understanding of the evolutionary and epidemiological factors that shape viral global evolution as well as development of better antivirals and vaccines. However, little is known about how viral evolution of resistance to antivirals occurs clinically due to the lack of preclinical models that can faithfully model influenza infection in humans. Our study shows that influenza viral evolution through mutation or gene reassortment can be recapitulated in a human lung airway-on-a-chip (airway chip) microfluidic culture device that can faithfully recapitulate the influenza infection in vitro. This approach is useful for studying within-host viral evolution, evaluating viral drug resistance, and identifying potential influenza virus variants before they appear in human populations, thereby enabling the preemptive design of new and more effective vaccines and therapeutics.


Subject(s)
Drug Resistance, Viral/genetics , Evolution, Molecular , Influenza A virus/drug effects , Influenza A virus/genetics , Lab-On-A-Chip Devices , Amantadine/pharmacology , Antiviral Agents/pharmacology , Benzamidines/pharmacology , Guanidines/pharmacology , Humans , Influenza, Human/drug therapy , Influenza, Human/transmission , Lung/virology , Microfluidics , Oseltamivir/pharmacology , SARS-CoV-2/genetics
6.
Viruses ; 13(9)2021 09 04.
Article in English | MEDLINE | ID: covidwho-1390793

ABSTRACT

SARS-CoV-2 and its vaccine/immune-escaping variants continue to pose a serious threat to public health due to a paucity of effective, rapidly deployable, and widely available treatments. Here, we address these challenges by combining Pegasys (IFNα) and nafamostat to effectively suppress SARS-CoV-2 infection in cell culture and hamsters. Our results indicate that Serpin E1 is an important mediator of the antiviral activity of IFNα and that both Serpin E1 and nafamostat can target the same cellular factor TMPRSS2, which plays a critical role in viral replication. The low doses of the drugs in combination may have several clinical advantages, including fewer adverse events and improved patient outcome. Thus, our study may provide a proactive solution for the ongoing pandemic and potential future coronavirus outbreaks, which is still urgently required in many parts of the world.


Subject(s)
Anti-Inflammatory Agents, Non-Steroidal/pharmacology , Benzamidines/pharmacology , COVID-19/metabolism , COVID-19/virology , Guanidines/pharmacology , Interferon-alpha/pharmacology , SARS-CoV-2/drug effects , Serine Endopeptidases/metabolism , Animals , Anti-Inflammatory Agents, Non-Steroidal/therapeutic use , Benzamidines/therapeutic use , COVID-19/drug therapy , Cricetinae , Disease Models, Animal , Drug Therapy, Combination , Female , Guanidines/therapeutic use , Host-Pathogen Interactions/drug effects , Humans , Interferon-alpha/therapeutic use , Virus Replication/drug effects
7.
J Virol ; 95(21): e0097521, 2021 10 13.
Article in English | MEDLINE | ID: covidwho-1361966

ABSTRACT

Repurposing FDA-approved inhibitors able to prevent infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could provide a rapid path to establish new therapeutic options to mitigate the effects of coronavirus disease 2019 (COVID-19). Proteolytic cleavages of the spike (S) protein of SARS-CoV-2, mediated by the host cell proteases cathepsin and TMPRSS2, alone or in combination, are key early activation steps required for efficient infection. The PIKfyve kinase inhibitor apilimod interferes with late endosomal viral traffic and through an ill-defined mechanism prevents in vitro infection through late endosomes mediated by cathepsin. Similarly, inhibition of TMPRSS2 protease activity by camostat mesylate or nafamostat mesylate prevents infection mediated by the TMPRSS2-dependent and cathepsin-independent pathway. Here, we combined the use of apilimod with camostat mesylate or nafamostat mesylate and found an unexpected ∼5- to 10-fold increase in their effectiveness to prevent SARS-CoV-2 infection in different cell types. Comparable synergism was observed using both a chimeric vesicular stomatitis virus (VSV) containing S of SARS-CoV-2 (VSV-SARS-CoV-2) and SARS-CoV-2. The substantial ∼5-fold or higher decrease of the half-maximal effective concentrations (EC50s) suggests a plausible treatment strategy based on the combined use of these inhibitors. IMPORTANCE Infection by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is causing the coronavirus disease 2019 (COVID-2019) global pandemic. There are ongoing efforts to uncover effective antiviral agents that could mitigate the severity of the disease by controlling the ensuing viral replication. Promising candidates include small molecules that inhibit the enzymatic activities of host proteins, thus preventing SARS-CoV-2 entry and infection. They include apilimod, an inhibitor of PIKfyve kinase, and camostat mesylate and nafamostat mesylate, inhibitors of TMPRSS2 protease. Our research is significant for having uncovered an unexpected synergism in the effective inhibitory activity of apilimod used together with camostat mesylate or nafamostat mesylate.


Subject(s)
Antiviral Agents/pharmacology , Benzamidines/pharmacology , Esters/pharmacology , Guanidines/pharmacology , Hydrazones/pharmacology , Morpholines/pharmacology , Phosphatidylinositol 3-Kinases/metabolism , Pyrimidines/pharmacology , SARS-CoV-2/drug effects , Serine Endopeptidases/metabolism , Animals , COVID-19/drug therapy , Cell Line, Tumor , Chlorocebus aethiops , Drug Synergism , Humans , Phosphoinositide-3 Kinase Inhibitors/pharmacology , Protease Inhibitors/pharmacology , SARS-CoV-2/physiology , Vero Cells , Virus Internalization
8.
mBio ; 12(4): e0097021, 2021 08 31.
Article in English | MEDLINE | ID: covidwho-1338834

ABSTRACT

The coronavirus disease 2019 (COVID-19) pandemic has caused significant morbidity and mortality on a global scale. The etiologic agent, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), initiates host cell entry when its spike protein (S) binds to its receptor, angiotensin-converting enzyme 2 (ACE2). In airway epithelia, the spike protein is cleaved by the cell surface protease TMPRSS2, facilitating membrane fusion and entry at the cell surface. This dependence on TMPRSS2 and related proteases suggests that protease inhibitors might limit SARS-CoV-2 infection in the respiratory tract. Here, we tested two serine protease inhibitors, camostat mesylate and nafamostat mesylate, for their ability to inhibit entry of SARS-CoV-2 and that of a second pathogenic coronavirus, Middle East respiratory syndrome coronavirus (MERS-CoV). Both camostat and nafamostat reduced infection in primary human airway epithelia and in the Calu-3 2B4 cell line, with nafamostat exhibiting greater potency. We then assessed whether nafamostat was protective against SARS-CoV-2 in vivo using two mouse models. In mice sensitized to SARS-CoV-2 infection by transduction with human ACE2, intranasal nafamostat treatment prior to or shortly after SARS-CoV-2 infection significantly reduced weight loss and lung tissue titers. Similarly, prophylactic intranasal treatment with nafamostat reduced weight loss, viral burden, and mortality in K18-hACE2 transgenic mice. These findings establish nafamostat as a candidate for the prevention or treatment of SARS-CoV-2 infection and disease pathogenesis. IMPORTANCE The causative agent of COVID-19, severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), requires host cell surface proteases for membrane fusion and entry into airway epithelia. We tested the hypothesis that inhibitors of these proteases, the serine protease inhibitors camostat and nafamostat, block infection by SARS-CoV-2. We found that both camostat and nafamostat reduce infection in human airway epithelia, with nafamostat showing greater potency. We then asked whether nafamostat protects mice against SARS-CoV-2 infection and subsequent COVID-19 lung disease. We performed infections in mice made susceptible to SARS-CoV-2 infection by introducing the human version of ACE2, the SARS-CoV-2 receptor, into their airway epithelia. We observed that pretreating these mice with nafamostat prior to SARS-CoV-2 infection resulted in better outcomes, in the form of less virus-induced weight loss, viral replication, and mortality than that observed in the untreated control mice. These results provide preclinical evidence for the efficacy of nafamostat in treating and/or preventing COVID-19.


Subject(s)
Benzamidines/pharmacology , Esters/pharmacology , Guanidines/pharmacology , SARS-CoV-2/drug effects , Serine Endopeptidases/metabolism , Serine Proteinase Inhibitors/pharmacology , Virus Internalization/drug effects , Angiotensin-Converting Enzyme 2/genetics , Animals , COVID-19/drug therapy , Cells, Cultured , Disease Models, Animal , Drug Evaluation, Preclinical , Humans , Lung/pathology , Mice , Mice, Inbred C57BL , Mice, Transgenic , Middle East Respiratory Syndrome Coronavirus/drug effects , Respiratory Mucosa/pathology , Respiratory Mucosa/virology , Spike Glycoprotein, Coronavirus/metabolism
9.
Commun Biol ; 4(1): 682, 2021 06 03.
Article in English | MEDLINE | ID: covidwho-1260957

ABSTRACT

An outbreak of the novel coronavirus SARS-CoV-2, the causative agent of Coronavirus Disease-2019 (COVID-19), a respiratory disease, has infected almost one hundred million people since the end of 2019, killed over two million, and caused worldwide social and economic disruption. Because the mechanisms of SARS-CoV-2 infection of host cells and its pathogenesis remain largely unclear, there are currently no antiviral drugs with proven efficacy. Besides severe respiratory and systematic symptoms, several comorbidities increase risk of fatal disease outcome. Therefore, it is required to investigate the impacts of COVID-19 on pre-existing diseases of patients, such as cancer and other infectious diseases. In the current study, we report that SARS-CoV-2 encoded proteins and some currently used anti-COVID-19 drugs are able to induce lytic reactivation of Kaposi's sarcoma-associated herpesvirus (KSHV), one of major human oncogenic viruses, through manipulation of intracellular signaling pathways. Our data indicate that those KSHV + patients especially in endemic areas exposure to COVID-19 or undergoing the treatment may have increased risks to develop virus-associated cancers, even after they have fully recovered from COVID-19.


Subject(s)
Antiviral Agents/pharmacology , COVID-19/complications , Herpesvirus 8, Human/physiology , SARS-CoV-2/physiology , Sarcoma, Kaposi/etiology , Virus Activation , Azithromycin/pharmacology , Benzamidines/pharmacology , COVID-19/drug therapy , Cell Line , Guanidines/pharmacology , Herpesviridae Infections/chemically induced , Herpesviridae Infections/etiology , Herpesvirus 8, Human/drug effects , Humans , Oncogenic Viruses/drug effects , Oncogenic Viruses/physiology , SARS-CoV-2/drug effects , Sarcoma, Kaposi/chemically induced , Viral Proteins/metabolism , Virus Activation/drug effects
10.
Appl Biochem Biotechnol ; 193(6): 1909-1923, 2021 Jun.
Article in English | MEDLINE | ID: covidwho-1053100

ABSTRACT

The unprecedented coronavirus SARS-CoV-2 outbreak at Wuhan, China, caused acute respiratory infection to humans. There is no precise vaccine/therapeutic agents available to combat the COVID-19 disease. Some repurposed drugs are saving the life of diseased, but the complete cure is relatively less. Several drug targets have been reported to inhibit the SARS-CoV-2 virus infection, in that TMPRSS2 (transmembrane protease serine 2) is one of the potential targets; inhibiting this protease stops the virus entry into the host human cell. Camostat mesylate, nafamostat, and leupeptin are the drugs, in which the first two drugs are being used for COVID-19 and leupeptin also tested. To consider these drugs as the repurposed drug for COVID-19, it is essential to understand their binding affinity and stability with TMPRSS2. In the present study, we performed the molecular docking and molecular dynamics (MD) simulation of these molecules with the TMPRSS2. The docking study reveals that leupeptin molecule strongly binds with TMPRSS2 protein than the other two drug molecules. The RMSD and RMSF values of MD simulation confirm that leupeptin and the amino acids of TMPRSS2 are very stable than the other two molecules. Furthermore, leupeptin forms interactions with the key amino acids of TMPRSS2 and the same have been maintained during the MD simulations. This structural and dynamical information is useful to evaluate these drugs to be used as repurposed drugs, however, the strong binding profile of leupeptin with TMPRSS2, suggests, it may be considered as a repurposed drug for COVID-19 disease after clinical trial.


Subject(s)
Antiviral Agents/pharmacology , Benzamidines/therapeutic use , COVID-19/drug therapy , Drug Repositioning , Esters/therapeutic use , Guanidines/therapeutic use , Leupeptins/metabolism , Molecular Docking Simulation , Molecular Dynamics Simulation , Serine Endopeptidases/metabolism , Antiviral Agents/therapeutic use , Benzamidines/pharmacology , COVID-19/virology , Esters/pharmacology , Guanidines/pharmacology , Humans , Protein Binding , SARS-CoV-2/drug effects
11.
J Thromb Thrombolysis ; 51(3): 649-656, 2021 Apr.
Article in English | MEDLINE | ID: covidwho-754362

ABSTRACT

Critical illnesses associated with coronavirus disease 2019 (COVID-19) are attributable to a hypercoagulable status. There is limited knowledge regarding the dynamic changes in coagulation factors among COVID-19 patients on nafamostat mesylate, a potential therapeutic anticoagulant for COVID-19. First, we retrospectively conducted a cluster analysis based on clinical characteristics on admission to identify latent subgroups among fifteen patients with COVID-19 on nafamostat mesylate at the University of Tokyo Hospital, Japan, between April 6 and May 31, 2020. Next, we delineated the characteristics of all patients as well as COVID-19-patient subgroups and compared dynamic changes in coagulation factors among each subgroup. The subsequent dynamic changes in fibrinogen and D-dimer levels were presented graphically. All COVID-19 patients were classified into three subgroups: clusters A, B, and C, representing low, intermediate, and high risk of poor outcomes, respectively. All patients were alive 30 days from symptom onset. No patient in cluster A required mechanical ventilation; however, all patients in cluster C required mechanical ventilation, and half of them were treated with venovenous extracorporeal membrane oxygenation. All patients in cluster A maintained low D-dimer levels, but some critical patients in clusters B and C showed dynamic changes in fibrinogen and D-dimer levels. Although the potential of nafamostat mesylate needs to be evaluated in randomized clinical trials, admission characteristics of patients with COVID-19 could predict subsequent coagulopathy.


Subject(s)
Anticoagulants/therapeutic use , Benzamidines/therapeutic use , COVID-19/drug therapy , Fibrin Fibrinogen Degradation Products/metabolism , Fibrinogen/metabolism , Guanidines/therapeutic use , Aged , Anticoagulants/pharmacology , Benzamidines/pharmacology , COVID-19/blood , COVID-19/classification , Female , Fibrinogen/drug effects , Guanidines/pharmacology , Humans , Male , Middle Aged , Retrospective Studies
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