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1.
JCI Insight ; 7(5)2022 03 08.
Article in English | MEDLINE | ID: covidwho-1759583

ABSTRACT

Severe acute lung injury has few treatment options and a high mortality rate. Upon injury, neutrophils infiltrate the lungs and form neutrophil extracellular traps (NETs), damaging the lungs and driving an exacerbated immune response. Unfortunately, no drug preventing NET formation has completed clinical development. Here, we report that disulfiram - an FDA-approved drug for alcohol use disorder - dramatically reduced NETs, increased survival, improved blood oxygenation, and reduced lung edema in a transfusion-related acute lung injury (TRALI) mouse model. We then tested whether disulfiram could confer protection in the context of SARS-CoV-2 infection, as NETs are elevated in patients with severe COVID-19. In SARS-CoV-2-infected golden hamsters, disulfiram reduced NETs and perivascular fibrosis in the lungs, and it downregulated innate immune and complement/coagulation pathways, suggesting that it could be beneficial for patients with COVID-19. In conclusion, an existing FDA-approved drug can block NET formation and improve disease course in 2 rodent models of lung injury for which treatment options are limited.


Subject(s)
Acute Lung Injury/drug therapy , COVID-19/complications , Disulfiram/pharmacology , Extracellular Traps/drug effects , Lung/immunology , SARS-CoV-2 , Acetaldehyde Dehydrogenase Inhibitors/pharmacology , Acute Lung Injury/etiology , Animals , COVID-19/virology , Disease Models, Animal , Extracellular Traps/immunology , Rodentia
2.
Int Immunopharmacol ; 104: 108516, 2022 Mar.
Article in English | MEDLINE | ID: covidwho-1611782

ABSTRACT

Coronavirus disease 2019 (Covid-19) is a worldwide infectious disease caused by severe acute respiratory coronavirus 2 (SARS-CoV-2). In severe SARS-CoV-2 infection, there is severe inflammatory reactions due to neutrophil recruitments and infiltration in the different organs with the formation of neutrophil extracellular traps (NETs), which involved various complications of SARS-CoV-2 infection. Therefore, the objective of the present review was to explore the potential role of NETs in the pathogenesis of SARS-CoV-2 infection and to identify the targeting drugs against NETs in Covid-19 patients. Different enzyme types are involved in the formation of NETs, such as neutrophil elastase (NE), which degrades nuclear protein and release histones, peptidyl arginine deiminase type 4 (PADA4), which releases chromosomal DNA and gasdermin D, which creates pores in the NTs cell membrane that facilitating expulsion of NT contents. Despite of the beneficial effects of NETs in controlling of invading pathogens, sustained formations of NETs during respiratory viral infections are associated with collateral tissue injury. Excessive development of NETs in SARS-CoV-2 infection is linked with the development of acute lung injury (ALI) and acute respiratory distress syndrome (ARDS) due to creation of the NETs-IL-1ß loop. Also, aberrant NTs activation alone or through NETs formation may augment SARS-CoV-2-induced cytokine storm (CS) and macrophage activation syndrome (MAS) in patients with severe Covid-19. Furthermore, NETs formation in SARS-CoV-2 infection is associated with immuno-thrombosis and the development of ALI/ARDS. Therefore, anti-NETs therapy of natural or synthetic sources may mitigate SARS-CoV-2 infection-induced exaggerated immune response, hyperinflammation, immuno-thrombosis, and other complications.


Subject(s)
Acute Lung Injury/immunology , Anti-Inflammatory Agents/pharmacology , COVID-19/immunology , Cytokine Release Syndrome/immunology , Extracellular Traps/immunology , Acute Lung Injury/prevention & control , Acute Lung Injury/virology , Anti-Inflammatory Agents/therapeutic use , COVID-19/complications , COVID-19/drug therapy , COVID-19/virology , Cytokine Release Syndrome/prevention & control , Cytokine Release Syndrome/virology , Extracellular Traps/drug effects , Extracellular Traps/metabolism , Humans , Immunity, Innate/drug effects , Leukocyte Elastase/antagonists & inhibitors , Leukocyte Elastase/metabolism , Neutrophil Infiltration/drug effects , Phosphate-Binding Proteins/antagonists & inhibitors , Phosphate-Binding Proteins/metabolism , Pore Forming Cytotoxic Proteins/antagonists & inhibitors , Pore Forming Cytotoxic Proteins/metabolism , Protein-Arginine Deiminase Type 4/antagonists & inhibitors , Protein-Arginine Deiminase Type 4/metabolism , SARS-CoV-2/immunology
3.
JCI Insight ; 6(17)2021 09 08.
Article in English | MEDLINE | ID: covidwho-1413722

ABSTRACT

Neutrophil-mediated activation and injury of the endothelium play roles in the pathogenesis of diverse disease states ranging from autoimmunity to cancer to COVID-19. Neutralization of cationic proteins (such as neutrophil extracellular trap-derived [NET-derived] histones) with polyanionic compounds has been suggested as a potential strategy for protecting the endothelium from such insults. Here, we report that the US Food and Drug Administration-approved polyanionic agent defibrotide (a pleiotropic mixture of oligonucleotides) directly engages histones and thereby blocks their pathological effects on endothelium. In vitro, defibrotide counteracted endothelial cell activation and pyroptosis-mediated cell death, whether triggered by purified NETs or recombinant histone H4. In vivo, defibrotide stabilized the endothelium and protected against histone-accelerated inferior vena cava thrombosis in mice. Mechanistically, defibrotide demonstrated direct and tight binding to histone H4 as detected by both electrophoretic mobility shift assay and surface plasmon resonance. Taken together, these data provide insights into the potential role of polyanionic compounds in protecting the endothelium from thromboinflammation with potential implications for myriad NET- and histone-accelerated disease states.


Subject(s)
Fibrinolytic Agents/pharmacology , Human Umbilical Vein Endothelial Cells/drug effects , Polydeoxyribonucleotides/pharmacology , Thrombosis/drug therapy , Animals , Extracellular Traps/drug effects , Extracellular Traps/metabolism , Fibrinolytic Agents/therapeutic use , Histones/metabolism , Human Umbilical Vein Endothelial Cells/metabolism , Humans , Male , Mice , Mice, Inbred C57BL , Polydeoxyribonucleotides/therapeutic use , Pyroptosis
4.
Biochem Biophys Res Commun ; 565: 64-71, 2021 08 06.
Article in English | MEDLINE | ID: covidwho-1251023

ABSTRACT

Neutrophil extracellular traps (NETs) are extracellular webs of DNA, histones and granular contents that are released by neutrophils to control infections. However, NETs that is not properly regulated can propagate inflammation and thrombosis. It was recognized that viruses can induce NETs. As a synthetic analog of viral double-stranded (ds) RNA, polyinosinic-polycytidylic acid [poly(I:C)] is known to induce inflammation and thrombosis. However, whether and how poly(I:C) modulates NETs remains unclear. Here, we have demonstrated that poly(I:C) induced extracellular DNA traps in human neutrophils in a dose-dependent manner. Further, poly(I:C) or dsRNA virus elevated the levels of myeloperoxidase-DNA complexes and citrullinated histone H3, which are specific markers of NETs, in both neutrophil supernatants and mouse plasma. Interestingly, a potent peptidylarginine deiminase 4 (PAD4) inhibitor, BB-CL-Amidine (BB-CLA) or PAD4 knockdown effectively prevented poly(I:C)-induced NETs formation and release. In addition, BB-CLA abrogated poly(I:C)-triggered neutrophil activation and infiltration, and vascular permeability in lungs. BB-CLA also attenuated poly(I:C)-induced thrombocytopenia in circulation, fibrin deposition and thrombus formation in tissues. Taken together, these results suggest that viral mimetic poly(I:C) may induce NETs-dependent inflammation and thrombosis through PAD4, and that inhibiting PAD4 may become a good strategy to protect against viral infection-caused inflammation/thrombosis-related pathological conditions of diseases.


Subject(s)
Extracellular Traps/drug effects , Inflammation/metabolism , Neutrophils/drug effects , Poly I-C/pharmacology , Protein-Arginine Deiminase Type 4/metabolism , Thrombosis/metabolism , Amidines/pharmacology , Animals , Cells, Cultured , Chlorocebus aethiops , Humans , Inflammation/pathology , Male , Mice , Mice, Inbred C57BL , Neutrophil Activation/drug effects , Neutrophils/metabolism , Protein-Arginine Deiminase Type 4/antagonists & inhibitors , Thrombosis/pathology
5.
Blood Coagul Fibrinolysis ; 32(3): 167-171, 2021 Apr 01.
Article in English | MEDLINE | ID: covidwho-1171412

ABSTRACT

Coronavirus disease 2019 infection produce a prothrombotic state. This is initiated through multiple pathways and is finally aggravated by cross talks with cytokine storm and neutrophil, platelet, complement activation. All these combine towards the second week of illness to produce thrombosis in the lung capillaries surrounding the alveolus producing characteristic pulmonary dysfunction (PaO2/FiO2 > 300, normal or minimally increased lung compliance and very high d-dimer levels) and a high rate of peripheral venous thrombosis. International and many national guidelines have approached this state in different ways but all emphasized the need for management and prevention of widespread thrombosis. It is felt more aggressive and graded thrombosis prevention and management should be initiated early in the treatment. d-Dimer, neutrophil count, SaO2, fibrinogen levels should be used to control the hypercoagulability. Drugs like statins which have anti-inflammatory action as well as ability to reduce fibrinogen and other clotting factors should be used in the beginning along with antiplatelet drugs and progressively complement activation and neutrophil extracellular traps inhibitors, oral mucopolysaccharides, full-scale anticoagulation along with judicial use of fibrinolysis supporting drugs should be added. In the present review, we have evaluated the various studies and argued the rationality that the anticoagulation in this condition should be initiated early during the infection and should be increased in a graded manner depending on clinical and laboratory progression of the condition until a strong specific antiviral drug for coronavirus disease 2019 infection is available.


Subject(s)
Blood Coagulation/drug effects , COVID-19/drug therapy , COVID-19/physiopathology , Thrombophilia/drug therapy , Thrombosis/drug therapy , Anticoagulants/therapeutic use , Antiviral Agents/therapeutic use , Blood Platelets/drug effects , Extracellular Traps/drug effects , Fibrinolytic Agents/therapeutic use , Glycosaminoglycans/pharmacology , Glycosaminoglycans/therapeutic use , Humans , Hydroxymethylglutaryl-CoA Reductase Inhibitors/pharmacology , Hydroxymethylglutaryl-CoA Reductase Inhibitors/therapeutic use , Inflammation/drug therapy , Lung/drug effects , Lung/physiopathology , Lung/virology , Platelet Aggregation Inhibitors/therapeutic use
7.
Crit Care ; 25(1): 51, 2021 02 08.
Article in English | MEDLINE | ID: covidwho-1069580

ABSTRACT

BACKGROUND: Thrombosis and coagulopathy are highly prevalent in critically ill patients with COVID-19 and increase the risk of death. Immunothrombosis has recently been demonstrated to contribute to the thrombotic events in COVID-19 patients with coagulopathy. As the primary components of immunothrombosis, neutrophil extracellular traps (NETs) could be induced by complement cascade components and other proinflammatory mediators. We aimed to explore the clinical roles of NETs and the regulation of complement on the NET formation in COVID-19. METHODS: We recruited 135 COVID-19 patients and measured plasma levels of C5, C3, cell-free DNA and myeloperoxidase (MPO)-DNA. Besides, the formation of NETs was detected by immunofluorescent staining and the cytotoxicity to vascular endothelial HUVEC cells was evaluated by CCK-8 assay. RESULTS: We found that the plasma levels of complements C3 and MPO-DNA were positively related to coagulation indicator fibrin(-ogen) degradation products (C3: r = 0.300, p = 0.005; MPO-DNA: r = 0.316, p = 0.002) in COVID-19 patients. Besides, C3 was positively related to direct bilirubin (r = 0.303, p = 0.004) and total bilirubin (r = 0.304, p = 0.005), MPO-DNA was positively related to lactate dehydrogenase (r = 0.306, p = 0.003) and creatine kinase (r = 0.308, p = 0.004). By using anti-C3a and anti-C5a antibodies, we revealed that the complement component anaphylatoxins in the plasma of COVID-19 patients strongly induced NET formation. The pathological effect of the anaphylatoxin-NET axis on the damage of vascular endothelial cells could be relieved by recombinant carboxypeptidase B (CPB), a stable homolog of enzyme CPB2 which can degrade anaphylatoxins to inactive products. CONCLUSIONS: Over-activation in anaphylatoxin-NET axis plays a pathological role in COVID-19. Early intervention in anaphylatoxins might help prevent thrombosis and disease progression in COVID-19 patients.


Subject(s)
Anaphylatoxins/metabolism , COVID-19/drug therapy , COVID-19/immunology , Carboxypeptidase B/metabolism , Carboxypeptidase B/therapeutic use , Extracellular Traps/drug effects , Neutrophils/drug effects , Thrombosis/prevention & control , Adult , Aged , COVID-19/physiopathology , Extracellular Traps/immunology , Female , Humans , Male , Middle Aged , Neutrophils/immunology , Thrombosis/immunology
8.
J Neurovirol ; 27(1): 35-51, 2021 02.
Article in English | MEDLINE | ID: covidwho-1061059

ABSTRACT

Since the outbreak of coronavirus disease 2019 (COVID-19) in 2019, it is gaining worldwide attention at the moment. Apart from respiratory manifestations, neurological dysfunction in COVID-19 patients, especially the occurrence of cerebrovascular diseases (CVD), has been intensively investigated. In this review, the effects of COVID-19 infection on CVD were summarized as follows: (I) angiotensin-converting enzyme 2 (ACE2) may be involved in the attack on vascular endothelial cells by severe acute respiratory syndrome coronavirus-2 (SARS-CoV-2), leading to endothelial damage and increased subintimal inflammation, which are followed by hemorrhage or thrombosis; (II) SARS-CoV-2 could alter the expression/activity of ACE2, consequently resulting in the disruption of renin-angiotensin system which is associated with the occurrence and progression of atherosclerosis; (III) upregulation of neutrophil extracellular traps has been detected in COVID-19 patients, which is closely associated with immunothrombosis; (IV) the inflammatory cascade induced by SARS-CoV-2 often leads to hypercoagulability and promotes the formation and progress of atherosclerosis; (V) antiphospholipid antibodies are also detected in plasma of some severe cases, which aggravate the thrombosis through the formation of immune complexes; (VI) hyperglycemia in COVID-19 patients may trigger CVD by increasing oxidative stress and blood viscosity; (VII) the COVID-19 outbreak is a global emergency and causes psychological stress, which could be a potential risk factor of CVD as coagulation, and fibrinolysis may be affected. In this review, we aimed to further our understanding of CVD-associated COVID-19 infection, which could improve the therapeutic outcomes of patients. Personalized treatments should be offered to COVID-19 patients at greater risk for stroke in future clinical practice.


Subject(s)
Atherosclerosis/complications , COVID-19/complications , Disseminated Intravascular Coagulation/complications , Hemorrhage/complications , Hyperglycemia/complications , Stroke/complications , Thrombosis/complications , Anticoagulants/therapeutic use , Antiviral Agents/therapeutic use , Atherosclerosis/diagnosis , Atherosclerosis/drug therapy , Atherosclerosis/virology , COVID-19/diagnosis , COVID-19/drug therapy , COVID-19/virology , Cardiovascular Agents/therapeutic use , Disseminated Intravascular Coagulation/diagnosis , Disseminated Intravascular Coagulation/drug therapy , Disseminated Intravascular Coagulation/virology , Extracellular Traps/drug effects , Extracellular Traps/immunology , Hemorrhage/diagnosis , Hemorrhage/drug therapy , Hemorrhage/virology , Humans , Hyperglycemia/diagnosis , Hyperglycemia/drug therapy , Hyperglycemia/virology , Inflammation , Renin-Angiotensin System/drug effects , Renin-Angiotensin System/immunology , SARS-CoV-2/drug effects , SARS-CoV-2/pathogenicity , Stroke/diagnosis , Stroke/drug therapy , Stroke/virology , Thrombosis/diagnosis , Thrombosis/drug therapy , Thrombosis/virology
9.
J Infect Dis ; 223(6): 981-984, 2021 03 29.
Article in English | MEDLINE | ID: covidwho-990724

ABSTRACT

Neutrophil extracellular traps (NETs) contribute to immunothrombosis and have been associated with mortality in coronavirus disease 2019 (COVID-19). We stimulated donor neutrophils with plasma from patients with COVID-19 and demonstrated that R406 can abrogate the release of NETs. These data provide evidence for how fostamatinib may mitigate neutrophil-associated mechanisms contributing to COVID-19 immunopathogenesis.


Subject(s)
COVID-19/drug therapy , Extracellular Traps/drug effects , Neutrophils/drug effects , Oxazines/pharmacology , Pyridines/pharmacology , Aminopyridines , COVID-19/blood , COVID-19/pathology , Humans , Morpholines , Pyrimidines , SARS-CoV-2/isolation & purification
10.
Med Hypotheses ; 146: 110394, 2021 Jan.
Article in English | MEDLINE | ID: covidwho-919589

ABSTRACT

No definitive treatment for COVID-19 exists although promising results have been reported with remdesivir and glucocorticoids. Short of a truly effective preventive or curative vaccine against SARS-CoV-2, it is becoming increasingly clear that multiple pathophysiologic processes seen with COVID-19 as well as SARS-CoV-2 itself should be targeted. Because alpha-1-antitrypsin (AAT) embraces a panoply of biologic activities that may antagonize several pathophysiologic mechanisms induced by SARS-CoV-2, we hypothesize that this naturally occurring molecule is a promising agent to ameliorate COVID-19. We posit at least seven different mechanisms by which AAT may alleviate COVID-19. First, AAT is a serine protease inhibitor (SERPIN) shown to inhibit TMPRSS-2, the host serine protease that cleaves the spike protein of SARS-CoV-2, a necessary preparatory step for the virus to bind its cell surface receptor ACE2 to gain intracellular entry. Second, AAT has anti-viral activity against other RNA viruses HIV and influenza as well as induces autophagy, a known host effector mechanism against MERS-CoV, a related coronavirus that causes the Middle East Respiratory Syndrome. Third, AAT has potent anti-inflammatory properties, in part through inhibiting both nuclear factor-kappa B (NFκB) activation and ADAM17 (also known as tumor necrosis factor-alpha converting enzyme), and thus may dampen the hyper-inflammatory response of COVID-19. Fourth, AAT inhibits neutrophil elastase, a serine protease that helps recruit potentially injurious neutrophils and implicated in acute lung injury. AAT inhibition of ADAM17 also prevents shedding of ACE2 and hence may preserve ACE2 inhibition of bradykinin, reducing the ability of bradykinin to cause a capillary leak in COVID-19. Fifth, AAT inhibits thrombin, and venous thromboembolism and in situ microthrombi and macrothrombi are increasingly implicated in COVID-19. Sixth, AAT inhibition of elastase can antagonize the formation of neutrophil extracellular traps (NETs), a complex extracellular structure comprised of neutrophil-derived DNA, histones, and proteases, and implicated in the immunothrombosis of COVID-19; indeed, AAT has been shown to change the shape and adherence of non-COVID-19-related NETs. Seventh, AAT inhibition of endothelial cell apoptosis may limit the endothelial injury linked to severe COVID-19-associated acute lung injury, multi-organ dysfunction, and pre-eclampsia-like syndrome seen in gravid women. Furthermore, because both NETs formation and the presence of anti-phospholipid antibodies are increased in both COVID-19 and non-COVID pre-eclampsia, it suggests a similar vascular pathogenesis in both disorders. As a final point, AAT has an excellent safety profile when administered to patients with AAT deficiency and is dosed intravenously once weekly but also comes in an inhaled preparation. Thus, AAT is an appealing drug candidate to treat COVID-19 and should be studied.


Subject(s)
COVID-19/drug therapy , Models, Biological , alpha 1-Antitrypsin/therapeutic use , Acute Lung Injury/drug therapy , Anti-Inflammatory Agents/therapeutic use , Antithrombins/therapeutic use , Antiviral Agents/therapeutic use , Apoptosis/drug effects , COVID-19/physiopathology , Extracellular Traps/drug effects , Host Microbial Interactions/drug effects , Host Microbial Interactions/physiology , Humans , Leukocyte Elastase/antagonists & inhibitors , Pandemics , SARS-CoV-2/drug effects , SARS-CoV-2/pathogenicity , SARS-CoV-2/physiology , Serine Endopeptidases/drug effects , Serine Endopeptidases/physiology , Virus Internalization/drug effects , alpha 1-Antitrypsin/administration & dosage
11.
Biomaterials ; 267: 120389, 2021 01.
Article in English | MEDLINE | ID: covidwho-898508

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is a new strain of coronavirus not previously identified in humans. Globally, the number of confirmed cases and mortality rates of coronavirus disease 2019 (COVID-19) have risen dramatically. Currently, there are no FDA-approved antiviral drugs and there is an urgency to develop treatment strategies that can effectively suppress SARS-CoV-2-mediated cytokine storms, acute respiratory distress syndrome (ARDS), and sepsis. As symptoms progress in patients with SARS-CoV-2 sepsis, elevated amounts of cell-free DNA (cfDNA) are produced, which in turn induce multiple organ failure in these patients. Furthermore, plasma levels of DNase-1 are markedly reduced in SARS-CoV-2 sepsis patients. In this study, we generated recombinant DNase-1-coated polydopamine-poly(ethylene glycol) nanoparticulates (named long-acting DNase-1), and hypothesized that exogenous administration of long-acting DNase-1 may suppress SARS-CoV-2-mediated neutrophil activities and the cytokine storm. Our findings suggest that exogenously administered long-acting nanoparticulate DNase-1 can effectively reduce cfDNA levels and neutrophil activities and may be used as a potential therapeutic intervention for life-threatening SARS-CoV-2-mediated illnesses.


Subject(s)
COVID-19/complications , Cytokine Release Syndrome/drug therapy , DNA/blood , Deoxyribonuclease I/therapeutic use , Drug Carriers/administration & dosage , Nanoparticles/administration & dosage , Neutrophils/drug effects , SARS-CoV-2 , Sepsis/drug therapy , Animals , COVID-19/blood , COVID-19/immunology , Cytokine Release Syndrome/etiology , Deoxyribonuclease I/administration & dosage , Dexamethasone/therapeutic use , Disease Models, Animal , Drug Evaluation, Preclinical , Extracellular Traps/drug effects , Humans , Indoles , Male , Mice , Mice, Inbred C57BL , Multiple Organ Failure/blood , Multiple Organ Failure/etiology , Multiple Organ Failure/prevention & control , NF-kappa B/blood , Neutrophils/enzymology , Peroxidase/blood , Polyethylene Glycols , Polyglactin 910 , Polymers , Sepsis/etiology , Sepsis/immunology
12.
Clin Immunol ; 220: 108598, 2020 11.
Article in English | MEDLINE | ID: covidwho-778645

ABSTRACT

Growing clinical evidence has implicated complement as a pivotal driver of COVID-19 immunopathology. Deregulated complement activation may fuel cytokine-driven hyper-inflammation, thrombotic microangiopathy and NET-driven immunothrombosis, thereby leading to multi-organ failure. Complement therapeutics have gained traction as candidate drugs for countering the detrimental consequences of SARS-CoV-2 infection. Whether blockade of terminal complement effectors (C5, C5a, or C5aR1) may elicit similar outcomes to upstream intervention at the level of C3 remains debated. Here we compare the efficacy of the C5-targeting monoclonal antibody eculizumab with that of the compstatin-based C3-targeted drug candidate AMY-101 in small independent cohorts of severe COVID-19 patients. Our exploratory study indicates that therapeutic complement inhibition abrogates COVID-19 hyper-inflammation. Both C3 and C5 inhibitors elicit a robust anti-inflammatory response, reflected by a steep decline in C-reactive protein and IL-6 levels, marked lung function improvement, and resolution of SARS-CoV-2-associated acute respiratory distress syndrome (ARDS). C3 inhibition afforded broader therapeutic control in COVID-19 patients by attenuating both C3a and sC5b-9 generation and preventing FB consumption. This broader inhibitory profile was associated with a more robust decline of neutrophil counts, attenuated neutrophil extracellular trap (NET) release, faster serum LDH decline, and more prominent lymphocyte recovery. These early clinical results offer important insights into the differential mechanistic basis and underlying biology of C3 and C5 inhibition in COVID-19 and point to a broader pathogenic involvement of C3-mediated pathways in thromboinflammation. They also support the evaluation of these complement-targeting agents as COVID-19 therapeutics in large prospective trials.


Subject(s)
Betacoronavirus/pathogenicity , Complement C3/antagonists & inhibitors , Complement C5/antagonists & inhibitors , Complement Inactivating Agents/therapeutic use , Coronavirus Infections/drug therapy , Immunologic Factors/therapeutic use , Pneumonia, Viral/drug therapy , Respiratory Distress Syndrome/drug therapy , Antibodies, Monoclonal, Humanized/therapeutic use , Biomarkers/blood , C-Reactive Protein/metabolism , COVID-19 , Cohort Studies , Complement Activation/drug effects , Complement C3/genetics , Complement C3/immunology , Complement C5/genetics , Complement C5/immunology , Coronavirus Infections/complications , Coronavirus Infections/immunology , Coronavirus Infections/virology , Extracellular Traps/drug effects , Female , Gene Expression , Humans , Interleukin-6/metabolism , Male , Middle Aged , Neutrophils/drug effects , Neutrophils/immunology , Neutrophils/virology , Pandemics , Peptides, Cyclic/therapeutic use , Pneumonia, Viral/complications , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Respiratory Distress Syndrome/complications , Respiratory Distress Syndrome/immunology , Respiratory Distress Syndrome/virology , SARS-CoV-2 , Severity of Illness Index
13.
Front Immunol ; 11: 2056, 2020.
Article in English | MEDLINE | ID: covidwho-769214

ABSTRACT

The pandemic of coronavirus disease 2019 (COVID-19), a disease which causes severe lung injury and multiple organ damage, presents an urgent need for new drugs. The case severity and fatality of COVID-19 are associated with excessive inflammation, namely, a cytokine storm. Metformin, a widely used drug to treat type 2 diabetes (T2D) mellitus and metabolic syndrome, has immunomodulatory activity that reduces the production of proinflammatory cytokines using macrophages and causes the formation of neutrophil extracellular traps (NETs). Metformin also inhibits the cytokine production of pathogenic Th1 and Th17 cells. Importantly, treatment with metformin alleviates various lung injuries in preclinical animal models. In addition, a recent proteomic study revealed that metformin has the potential to directly inhibit SARS-CoV-2 infection. Furthermore, retrospective clinical studies have revealed that metformin treatment reduces the mortality of T2D with COVID-19. Therefore, metformin has the potential to be repurposed to treat patients with COVID-19 at risk of developing severe illness. This review summarizes the immune pathogenesis of SARS-CoV-2 and addresses the effects of metformin on inhibiting cytokine storms and preventing SARS-CoV-2 infection, as well as its side effects.


Subject(s)
Antiviral Agents/therapeutic use , Betacoronavirus , Coronavirus Infections/drug therapy , Immunologic Factors/therapeutic use , Lung Injury/drug therapy , Metformin/therapeutic use , Pneumonia, Viral/drug therapy , Animals , Antiviral Agents/adverse effects , Antiviral Agents/pharmacology , COVID-19 , Coronavirus Infections/immunology , Coronavirus Infections/virology , Cytokines/antagonists & inhibitors , Drug Repositioning/methods , Extracellular Traps/drug effects , Humans , Immunologic Factors/adverse effects , Immunologic Factors/pharmacology , Inflammation/drug therapy , Macrophages/drug effects , Macrophages/immunology , Metformin/adverse effects , Metformin/pharmacology , Pandemics , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , SARS-CoV-2 , Th1 Cells/drug effects , Th1 Cells/immunology , Th17 Cells/drug effects , Th17 Cells/immunology
14.
Redox Biol ; 37: 101721, 2020 10.
Article in English | MEDLINE | ID: covidwho-759289

ABSTRACT

This review focuses on the hypothetical mechanisms for enhanced vulnerability of African Americans to SARS-CoV-2 infection, COVID-19 severity, and increased deaths. A disproportionately higher number of African Americans are afflicted with autoimmune and inflammatory diseases (e.g., diabetes, hypertension, obesity), and SARS-CoV-2 has helped expose these health disparities. Several factors including socioeconomic status, inferior health care, and work circumstances contribute to these disparities. Identifying potential inflammatory biomarkers and decreasing basal levels in high-risk individuals with comorbidities through preventive measures is critical. Immune cells, particularly neutrophils, protect us against pathogens (bacteria, fungi, and viruses) through increased generation of free radicals or oxidants and neutrophil extracellular traps (NETs) that ensnare pathogens, killing them extracellularly. However, continued generation of NETs coupled with the lack of prompt removal pose danger to host cells. NET levels are increased during pro-inflammatory diseases. COVID-19 patients exhibit elevated NET levels, depending upon disease severity. Conceivably, high-risk individuals with elevated basal NET levels would exhibit hyper-inflammation when infected with SARS-CoV-2, amplifying disease severity and deaths. Drugs inhibiting oxidant formation and vitamin supplements decreased NET formation in mice models of inflammation. Thus, it is conceivable that preventive treatments lowering NET levels and inflammation in high-risk individuals could mitigate SARS-CoV-2-induced complications and decrease mortality.


Subject(s)
COVID-19/metabolism , Extracellular Traps/metabolism , Inflammation/metabolism , Oxidative Stress , SARS-CoV-2/physiology , African Americans , Animals , Antioxidants/pharmacology , Antioxidants/therapeutic use , COVID-19/drug therapy , COVID-19/epidemiology , Drug Repositioning , Extracellular Traps/drug effects , Free Radicals/metabolism , Humans , Inflammation/drug therapy , Inflammation/epidemiology , Neutrophils/drug effects , Neutrophils/metabolism , Oxidative Stress/drug effects , Risk Factors , SARS-CoV-2/drug effects
16.
Nat Rev Immunol ; 20(9): 515-516, 2020 09.
Article in English | MEDLINE | ID: covidwho-690707
17.
Mediators Inflamm ; 2020: 7527953, 2020.
Article in English | MEDLINE | ID: covidwho-656906

ABSTRACT

COVID-19 is a pandemic disease caused by the new coronavirus SARS-CoV-2 that mostly affects the respiratory system. The consequent inflammation is not able to clear viruses. The persistent excessive inflammatory response can build up a clinical picture that is very difficult to manage and potentially fatal. Modulating the immune response plays a key role in fighting the disease. One of the main defence systems is the activation of neutrophils that release neutrophil extracellular traps (NETs) under the stimulus of autophagy. Various molecules can induce NETosis and autophagy; some potent activators are damage-associated molecular patterns (DAMPs) and, in particular, the high-mobility group box 1 (HMGB1). This molecule is released by damaged lung cells and can induce a robust innate immunity response. The increase in HMGB1 and NETosis could lead to sustained inflammation due to SARS-CoV-2 infection. Therefore, blocking these molecules might be useful in COVID-19 treatment and should be further studied in the context of targeted therapy.


Subject(s)
Alarmins/immunology , Betacoronavirus , Coronavirus Infections/drug therapy , Coronavirus Infections/immunology , Extracellular Traps/immunology , Pneumonia, Viral/drug therapy , Pneumonia, Viral/immunology , Alarmins/antagonists & inhibitors , Autophagy/immunology , Betacoronavirus/immunology , COVID-19 , Coronavirus Infections/pathology , Extracellular Traps/drug effects , HMGB1 Protein/antagonists & inhibitors , HMGB1 Protein/immunology , Host Microbial Interactions/immunology , Humans , Interleukin-6/antagonists & inhibitors , Interleukin-6/immunology , Lung/immunology , Lung/pathology , Pandemics , Pneumonia, Viral/pathology , SARS-CoV-2
18.
Adv Biol Regul ; 77: 100741, 2020 08.
Article in English | MEDLINE | ID: covidwho-623932

ABSTRACT

Pandemic coronavirus disease 2019 (COVID-19) is caused by severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) and poses an unprecedented challenge to healthcare systems due to the lack of a vaccine and specific treatment options. Accordingly, there is an urgent need to understand precisely the pathogenic mechanisms underlying this multifaceted disease. There is increasing evidence that the immune system reacts insufficiently to SARS-CoV-2 and thus contributes to organ damage and to lethality. In this review, we suggest that the overwhelming production of reactive oxygen species (ROS) resulting in oxidative stress is a major cause of local or systemic tissue damage that leads to severe COVID-19. It increases the formation of neutrophil extracellular traps (NETs) and suppresses the adaptive arm of the immune system, i.e. T cells that are necessary to kill virus-infected cells. This creates a vicious cycle that prevents a specific immune response against SARS-CoV-2. The key role of oxidative stress in the pathogenesis of severe COVID-19 implies that therapeutic counterbalancing of ROS by antioxidants such as vitamin C or NAC and/or by antagonizing ROS production by cells of the mononuclear phagocyte system (MPS) and neutrophil granulocytes and/or by blocking of TNF-α can prevent COVID-19 from becoming severe. Controlled clinical trials and preclinical models of COVID-19 are needed to evaluate this hypothesis.


Subject(s)
Antioxidants/therapeutic use , Coronavirus Infections/epidemiology , Extracellular Traps/immunology , Lymphopenia/epidemiology , Neutrophils/immunology , Pandemics , Pneumonia, Viral/epidemiology , Acetylcysteine/therapeutic use , Ascorbic Acid/therapeutic use , Betacoronavirus/immunology , Betacoronavirus/pathogenicity , COVID-19 , Coronavirus Infections/drug therapy , Coronavirus Infections/immunology , Coronavirus Infections/virology , Cytokines/genetics , Cytokines/immunology , Extracellular Traps/drug effects , Extracellular Traps/metabolism , Host-Pathogen Interactions/drug effects , Host-Pathogen Interactions/genetics , Host-Pathogen Interactions/immunology , Humans , Immunity, Innate/drug effects , Lymphopenia/drug therapy , Lymphopenia/immunology , Lymphopenia/virology , NF-kappa B/genetics , NF-kappa B/immunology , Neutrophils/drug effects , Neutrophils/virology , Oxidative Stress/drug effects , Pneumonia, Viral/drug therapy , Pneumonia, Viral/immunology , Pneumonia, Viral/virology , Reactive Oxygen Species/antagonists & inhibitors , Reactive Oxygen Species/immunology , Reactive Oxygen Species/metabolism , SARS-CoV-2 , T-Lymphocytes/drug effects , T-Lymphocytes/immunology , T-Lymphocytes/virology
19.
Med Hypotheses ; 143: 109906, 2020 Oct.
Article in English | MEDLINE | ID: covidwho-437087

ABSTRACT

Most COVID-19 infected individuals present with mild flu-like symptoms; however, 5-10% of cases suffer from life-threatening pneumonia and respiratory failure. The pathogenesis of SARS-CoV-2 and its pathology of associated acute lung injury (ALI), acute respiratory distress syndrome (ARDS), sepsis, coagulopathy and multiorgan failure is not known. SARS-CoV-2 is an envelope virus with S (spike), M (membrane), N (nucleocapsid) and E (envelop) proteins. In a closely related coronavirus (SARS-CoV), the transmembrane E protein exerts an important role in membrane-ionic transport through viroporins, deletion of which reduced levels of IL-1ß and a remarkably reduced lung edema compared to wild type. IL-1ß is generated by macrophages upon activation of intracellular NLRP3 (NOD-like, leucine rich repeat domains, and pyrin domain-containing protein 3), part of the functional NLRP3 inflammasome complex that detects pathogenic microorganisms and stressors, while neutrophils are enhanced by increasing levels of IL-1ß. Expiring neutrophils undergo "NETosis", producing thread-like extracellular structures termed neutrophil extracellular traps (NETs), which protect against mild infections and microbes. However, uncontrolled NET production can cause acute lung injury (ALI) and acute respiratory distress syndrome (ARDS), coagulopathy, multiple organ failure, and autoimmune disease. Herein, we present arguments underlying our hypothesis that IL-1ß and NETs, mediated via NLRP3 inflammasomes, form a feed-forward loop leading to the excessive alveolar and endothelial damage observed in severe cases of COVID-19. Considering such assertions, we propose potential drug candidates that could be used to alleviate such pathologies. Considering that recent efforts to ascertain effective treatments of COVID-19 in severe patients has been less than successful, investigating novel avenues of treating this virus are essential.


Subject(s)
Acute Lung Injury/drug therapy , Acute Lung Injury/etiology , Betacoronavirus , Coronavirus Infections/complications , Coronavirus Infections/drug therapy , Extracellular Traps/drug effects , Interleukin-1beta/antagonists & inhibitors , Pneumonia, Viral/complications , Pneumonia, Viral/drug therapy , Acute Lung Injury/immunology , COVID-19 , Coronavirus Infections/immunology , Extracellular Traps/immunology , Feedback, Physiological , Humans , Inflammasomes/immunology , Interleukin-1beta/immunology , Models, Biological , NLR Family, Pyrin Domain-Containing 3 Protein/immunology , Pandemics , Pneumonia, Viral/immunology , SARS-CoV-2
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