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1.
Molecules ; 27(6)2022 Mar 17.
Article in English | MEDLINE | ID: covidwho-1753654

ABSTRACT

This article discusses the importance of D-xylose for fighting viruses (especially SARS-CoV-2) that use core proteins as receptors at the cell surface, by providing additional supporting facts that these viruses probably bind at HS/CS attachment sites (i.e., the hydroxyl groups of Ser/Thr residues of the core proteins intended to receive the D-xylose molecules to initiate the HS/CS chains). Essentially, the additional supporting facts, are: some anterior studies on the binding sites of exogenous heparin and soluble HS on the core proteins, the inhibition of the viral entry by pre-incubation of cells with heparin, and additionally, corroborating studies about the mechanism leading to type 2 diabetes during viral infection. We then discuss the mechanism by which serine protease inhibitors inhibit SARS-CoV-2 entry. The biosynthesis of heparan sulfate (HS), chondroitin sulfate (CS), dermatan sulfate (DS), and heparin (Hep) is initiated not only by D-xylose derived from uridine diphosphate (UDP)-xylose, but also bioactive D-xylose molecules, even in situations where cells were previously treated with GAG inhibitors. This property of D-xylose shown by previous anterior studies helped in the explanation of the mechanism leading to type 2 diabetes during SARS-CoV-2 infection. This explanation is completed here by a preliminary estimation of xyloside GAGs (HS/CS/DS/Hep) in the body, and with other previous studies helping to corroborate the mechanism by which the D-xylose exhibits its antiglycaemic properties and the mechanism leading to type 2 diabetes during SARS-CoV-2 infection. This paper also discusses the confirmatory studies of regarding the correlation between D-xylose and COVID-19 severity.


Subject(s)
COVID-19 , Diabetes Mellitus, Type 2 , COVID-19/drug therapy , Heparin/metabolism , Heparin/pharmacology , Heparitin Sulfate/metabolism , Humans , SARS-CoV-2 , Serine Proteinase Inhibitors
2.
Int J Mol Sci ; 23(3)2022 Jan 24.
Article in English | MEDLINE | ID: covidwho-1686810

ABSTRACT

Aortic aneurysms are sometimes associated with enhanced-fibrinolytic-type disseminated intravascular coagulation (DIC). In enhanced-fibrinolytic-type DIC, both coagulation and fibrinolysis are markedly activated. Typical cases show decreased platelet counts and fibrinogen levels, increased concentrations of fibrin/fibrinogen degradation products (FDP) and D-dimer, and increased FDP/D-dimer ratios. Thrombin-antithrombin complex or prothrombin fragment 1 + 2, as markers of coagulation activation, and plasmin-α2 plasmin inhibitor complex, a marker of fibrinolytic activation, are all markedly increased. Prolongation of prothrombin time (PT) is not so obvious, and the activated partial thromboplastin time (APTT) is rather shortened in some cases. As a result, DIC can be neither diagnosed nor excluded based on PT and APTT alone. Many of the factors involved in coagulation and fibrinolysis activation are serine proteases. Treatment of enhanced-fibrinolytic-type DIC requires consideration of how to control the function of these serine proteases. The cornerstone of DIC treatment is treatment of the underlying pathology. However, in some cases surgery is either not possible or exacerbates the DIC associated with aortic aneurysm. In such cases, pharmacotherapy becomes even more important. Unfractionated heparin, other heparins, synthetic protease inhibitors, recombinant thrombomodulin, and direct oral anticoagulants (DOACs) are agents that inhibit serine proteases, and all are effective against DIC. Inhibition of activated coagulation factors by anticoagulants is key to the treatment of DIC. Among them, DOACs can be taken orally and is useful for outpatient treatment. Combination therapy of heparin and nafamostat allows fine-adjustment of anticoagulant and antifibrinolytic effects. While warfarin is an anticoagulant, this agent is ineffective in the treatment of DIC because it inhibits the production of coagulation factors as substrates without inhibiting activated coagulation factors. In addition, monotherapy using tranexamic acid in cases of enhanced-fibrinolytic-type DIC may induce fatal thrombosis. If tranexamic acid is needed for DIC, combination with anticoagulant therapy is of critical importance.


Subject(s)
Aortic Aneurysm/complications , Disseminated Intravascular Coagulation/therapy , Fibrinolysis/drug effects , Anticoagulants/pharmacology , Antifibrinolytic Agents/blood , Fibrin Fibrinogen Degradation Products , Fibrinolysin , Fibrinolysis/physiology , Heparin/pharmacology , Humans , Partial Thromboplastin Time , Prothrombin Time , alpha-2-Antiplasmin
3.
Int J Mol Sci ; 23(3)2022 Feb 05.
Article in English | MEDLINE | ID: covidwho-1674671

ABSTRACT

Inflammation and thrombosis are closely intertwined in numerous disorders, including ischemic events and sepsis, as well as coronavirus disease 2019 (COVID-19). Thrombotic complications are markers of disease severity in both sepsis and COVID-19 and are associated with multiorgan failure and increased mortality. Immunothrombosis is driven by the complement/tissue factor/neutrophil axis, as well as by activated platelets, which can trigger the release of neutrophil extracellular traps (NETs) and release further effectors of immunothrombosis, including platelet factor 4 (PF4/CXCL4) and high-mobility box 1 protein (HMGB1). Many of the central effectors of deregulated immunothrombosis, including activated platelets and platelet-derived extracellular vesicles (pEVs) expressing PF4, soluble PF4, HMGB1, histones, as well as histone-decorated NETs, are positively charged and thus bind to heparin. Here, we provide evidence that adsorbents functionalized with endpoint-attached heparin efficiently deplete activated platelets, pEVs, PF4, HMGB1 and histones/nucleosomes. We propose that this elimination of central effectors of immunothrombosis, rather than direct binding of pathogens, could be of clinical relevance for mitigating thrombotic complications in sepsis or COVID-19 using heparin-functionalized adsorbents.


Subject(s)
Blood Proteins/isolation & purification , Heparin/pharmacology , /drug therapy , Blood Coagulation/physiology , Blood Platelets/metabolism , Blood Proteins/metabolism , COVID-19/metabolism , Extracellular Traps/immunology , Extracellular Traps/metabolism , HMGB Proteins/isolation & purification , HMGB Proteins/metabolism , HMGB1 Protein/isolation & purification , HMGB1 Protein/metabolism , Heparin/metabolism , Histones/isolation & purification , Histones/metabolism , Humans , Neutrophils/metabolism , Platelet Activation/immunology , Platelet Factor 4/isolation & purification , Platelet Factor 4/metabolism , SARS-CoV-2/pathogenicity , Sepsis/blood , Sepsis/metabolism , Thromboplastin/metabolism , Thrombosis/drug therapy
4.
BMC Pulm Med ; 22(1): 6, 2022 Jan 06.
Article in English | MEDLINE | ID: covidwho-1605048

ABSTRACT

BACKGROUND: Mortality in severe COVID-19 pneumonia is associated with thrombo-inflammation. Corticosteroids are given to attenuate the inflammation, but they are associated with thrombosis. The aims of this study were to determine the risk of venous thromboembolism between no methylprednisolone and methylprednisolone (dose versus duration) and to evaluate any synergistic dose-dependent association of heparin and methylprednisolone to 30 days in hospital survival. METHODS: This was a secondary analysis of a retrospective cohort. Patients included in this study were ≥ 18 years of age and admitted for severe COVID-19 pneumonia between March and June 2020 in 13 hospitals in New Jersey, United States. A propensity score analysis between administration of methylprednisolone and no methylprednisolone was fitted for 11 variables and Youden Index Method was used to determine cut-off between low dose and high dose methylprednisolone. Multivariate cox regression was to assess risk. RESULTS: In 759 patients, the incidence of venous thromboembolism was 9% of patients who received methylprednisolone and 3% of patients who did not receive methylprednisolone with a [RR 2.92 (95% CI 1.54, 5.55 P < 0.0001)]. There was a higher incidence of mechanical ventilation in the methylprednisolone group. The median d-dimer between patients with venous thromboembolism was higher compared to those without (P < 0.0003). However, the d-dimer was not statistically significant between those who had venous thromboembolism between methylprednisolone and no methylprednisolone groups (P = 0.40). There was no higher risk in high dose versus low dose [RR = 0.524 (95% CI 0.26, 1.06 P 0.4)]; however, the risk for venous thromboembolism between methylprednisolone for > 7 days and ≤ 7 days was statistically significant (RR 5.46 95% CI 2.87, 10.34 P < 0.0001). Patients who received low dose methylprednisolone and therapeutic heparin had a trend towards higher risk of mortality compared to prophylactic heparin (HR 1.81 95% CI 0.994 to 3.294) (P = 0.0522). There was no difference in 30 days in hospital survival between high dose methylprednisolone with prophylactic or therapeutic heparin (HR 0.827 95% CI 0.514 to 1.33) (P = 0.4335). CONCLUSION: Methylprednisolone for > 7 days had a higher association of venous thromboembolism. There was no added benefit of therapeutic heparin to methylprednisolone on mechanically ventilated patients.


Subject(s)
COVID-19/mortality , Heparin/pharmacology , Methylprednisolone/pharmacology , Venous Thromboembolism/prevention & control , Anticoagulants/pharmacology , COVID-19/complications , Follow-Up Studies , Glucocorticoids/pharmacology , Hospital Mortality/trends , Humans , Incidence , Retrospective Studies , SARS-CoV-2 , Survival Rate/trends , Time Factors , United States/epidemiology , Venous Thromboembolism/epidemiology , Venous Thromboembolism/etiology
5.
J Biol Chem ; 298(2): 101507, 2022 02.
Article in English | MEDLINE | ID: covidwho-1587357

ABSTRACT

Heparin, a naturally occurring glycosaminoglycan, has been found to have antiviral activity against severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative virus of COVID-19. To elucidate the mechanistic basis for the antiviral activity of heparin, we investigated the binding of heparin to the SARS-CoV-2 spike glycoprotein by means of sliding window docking, molecular dynamics simulations, and biochemical assays. Our simulations show that heparin binds at long, positively charged patches on the spike glycoprotein, thereby masking basic residues of both the receptor-binding domain (RBD) and the multifunctional S1/S2 site. Biochemical experiments corroborated the simulation results, showing that heparin inhibits the furin-mediated cleavage of spike by binding to the S1/S2 site. Our simulations showed that heparin can act on the hinge region responsible for motion of the RBD between the inactive closed and active open conformations of the spike glycoprotein. In simulations of the closed spike homotrimer, heparin binds the RBD and the N-terminal domain of two adjacent spike subunits and hinders opening. In simulations of open spike conformations, heparin induces stabilization of the hinge region and a change in RBD motion. Our results indicate that heparin can inhibit SARS-CoV-2 infection by three mechanisms: by allosterically hindering binding to the host cell receptor, by directly competing with binding to host heparan sulfate proteoglycan coreceptors, and by preventing spike cleavage by furin. Furthermore, these simulations provide insights into how host heparan sulfate proteoglycans can facilitate viral infection. Our results will aid the rational optimization of heparin derivatives for SARS-CoV-2 antiviral therapy.


Subject(s)
COVID-19/metabolism , Heparin/metabolism , Spike Glycoprotein, Coronavirus/metabolism , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Antiviral Agents/pharmacology , Binding Sites , COVID-19/drug therapy , Heparin/chemistry , Heparin/pharmacology , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Protein Binding , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/chemistry
6.
Viruses ; 14(1)2021 12 24.
Article in English | MEDLINE | ID: covidwho-1580407

ABSTRACT

Only a mere fraction of the huge variety of human pathogenic viruses can be targeted by the currently available spectrum of antiviral drugs. The severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) outbreak has highlighted the urgent need for molecules that can be deployed quickly to treat novel, developing or re-emerging viral infections. Sulfated polysaccharides are found on the surfaces of both the susceptible host cells and the majority of human viruses, and thus can play an important role during viral infection. Such polysaccharides widely occurring in natural sources, specifically those converted into sulfated varieties, have already proved to possess a high level and sometimes also broad-spectrum antiviral activity. This antiviral potency can be determined through multifold molecular pathways, which in many cases have low profiles of cytotoxicity. Consequently, several new polysaccharide-derived drugs are currently being investigated in clinical settings. We reviewed the present status of research on sulfated polysaccharide-based antiviral agents, their structural characteristics, structure-activity relationships, and the potential of clinical application. Furthermore, the molecular mechanisms of sulfated polysaccharides involved in viral infection or in antiviral activity, respectively, are discussed, together with a focus on the emerging methodology contributing to polysaccharide-based drug development.


Subject(s)
Antiviral Agents/pharmacology , Biological Products/pharmacology , COVID-19/epidemiology , Polysaccharides/pharmacology , Viruses/drug effects , Antiviral Agents/chemical synthesis , Antiviral Agents/chemistry , Biological Products/chemical synthesis , Biological Products/chemistry , COVID-19/drug therapy , Heparin/chemical synthesis , Heparin/chemistry , Heparin/pharmacology , Humans , Polysaccharides/chemistry , SARS-CoV-2/drug effects , Structure-Activity Relationship , Sulfates/chemistry , Sulfates/pharmacology , Virus Diseases/drug therapy , Virus Internalization/drug effects , Viruses/pathogenicity
7.
Int J Mol Sci ; 22(18)2021 Sep 17.
Article in English | MEDLINE | ID: covidwho-1430892

ABSTRACT

Previous studies reported on the broad-spectrum antiviral function of heparin. Here we investigated the antiviral function of magnesium-modified heparin and found that modified heparin displayed a significantly enhanced antiviral function against human adenovirus (HAdV) in immortalized and primary cells. Nuclear magnetic resonance analyses revealed a conformational change of heparin when complexed with magnesium. To broadly explore this discovery, we tested the antiviral function of modified heparin against herpes simplex virus type 1 (HSV-1) and found that the replication of HSV-1 was even further decreased compared to aciclovir. Moreover, we investigated the antiviral effect against the new severe acute respiratory syndrome coronavirus type 2 (SARS-CoV-2) and measured a 55-fold decreased viral load in the supernatant of infected cells associated with a 38-fold decrease in virus growth. The advantage of our modified heparin is an increased antiviral effect compared to regular heparin.


Subject(s)
Antiviral Agents/pharmacology , Heparin/pharmacology , Magnesium Chloride/pharmacology , Acyclovir/pharmacology , Adenoviruses, Human/drug effects , Adenoviruses, Human/physiology , Animals , Antiviral Agents/chemistry , CHO Cells , Cell Line, Tumor , Chlorocebus aethiops , Cricetulus , Drug Evaluation, Preclinical , Fibroblasts , Heparin/chemistry , Herpesvirus 1, Human/drug effects , Herpesvirus 1, Human/physiology , Humans , Magnesium Chloride/chemistry , Magnetic Resonance Spectroscopy , Microbial Sensitivity Tests , Molecular Structure , Primary Cell Culture , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Structure-Activity Relationship , Vero Cells , Viral Load/drug effects , Virus Replication/drug effects
9.
Crit Care ; 25(1): 299, 2021 08 19.
Article in English | MEDLINE | ID: covidwho-1367680

ABSTRACT

BACKGROUND: Coronavirus disease 2019 (COVID-19) may predispose patients to thrombotic events. The best anticoagulation strategy for continuous renal replacement therapy (CRRT) in such patients is still under debate. The purpose of this study was to evaluate the impact that different anticoagulation protocols have on filter clotting risk. METHODS: This was a retrospective observational study comparing two different anticoagulation strategies (citrate only and citrate plus intravenous infusion of unfractionated heparin) in patients with acute kidney injury (AKI), associated or not with COVID-19 (COV + AKI and COV - AKI, respectively), who were submitted to CRRT. Filter clotting risks were compared among groups. RESULTS: Between January 2019 and July 2020, 238 patients were evaluated: 188 in the COV + AKI group and 50 in the COV - AKI group. Filter clotting during the first filter use occurred in 111 patients (46.6%). Heparin use conferred protection against filter clotting (HR = 0.37, 95% CI 0.25-0.55), resulting in longer filter survival. Bleeding events and the need for blood transfusion were similar between the citrate only and citrate plus unfractionated heparin strategies. In-hospital mortality was higher among the COV + AKI patients than among the COV - AKI patients, although it was similar between the COV + AKI patients who received heparin and those who did not. Filter clotting was more common in patients with D-dimer levels above the median (5990 ng/ml). In the multivariate analysis, heparin was associated with a lower risk of filter clotting (HR = 0.28, 95% CI 0.18-0.43), whereas an elevated D-dimer level and high hemoglobin were found to be risk factors for circuit clotting. A diagnosis of COVID-19 was marginally associated with an increased risk of circuit clotting (HR = 2.15, 95% CI 0.99-4.68). CONCLUSIONS: In COV + AKI patients, adding systemic heparin to standard regional citrate anticoagulation may prolong CRRT filter patency by reducing clotting risk with a low risk of complications.


Subject(s)
Acute Kidney Injury/drug therapy , Citric Acid/pharmacology , Continuous Renal Replacement Therapy/instrumentation , Heparin/pharmacology , Micropore Filters/standards , Acute Kidney Injury/epidemiology , Acute Kidney Injury/etiology , Adult , COVID-19/complications , COVID-19/epidemiology , Citric Acid/adverse effects , Citric Acid/therapeutic use , Cohort Studies , Continuous Renal Replacement Therapy/methods , Continuous Renal Replacement Therapy/statistics & numerical data , Female , Heparin/adverse effects , Heparin/therapeutic use , Humans , Kaplan-Meier Estimate , Male , Micropore Filters/statistics & numerical data , Middle Aged , Proportional Hazards Models , Retrospective Studies
10.
Curr Res Transl Med ; 69(4): 103300, 2021 10.
Article in English | MEDLINE | ID: covidwho-1294187

ABSTRACT

Heparin has served as a mainstream anticoagulant for over eight decades. Clinically heparin-derived compounds significantly contribute to prevention and treatment of thrombotic events complicated in numerous medical conditions such as venous thromboembolism, coronary artery disease and extracorporeal circulation processes. Moreover in recent years, various off-labeled efficacious potentials of heparin beyond anti-coagulation are dramatically emerging, and increasingly investigated in clinical studies. Herein this article presents a comprehensive update on the expanded applications of heparin agents, covering the pregnant clinic, respiratory inflammation, renal disease, sepsis, pancreatitis, among others. It aims to maximize the beneficial profile of a pharmaceutical product through medical re-purposing development, exemplified by heparin, to address the unmet clinical needs of severe illness including coronavirus disease 2019 (COVID-19).


Subject(s)
COVID-19/drug therapy , Drug Repositioning , Heparin/therapeutic use , SARS-CoV-2 , Abortion, Habitual/prevention & control , Burns/drug therapy , COVID-19/blood , COVID-19/complications , Female , Forecasting , Heparin/pharmacology , Humans , Neoplasms/blood , Neoplasms/complications , Nephrotic Syndrome/drug therapy , Pancreatitis/drug therapy , Pregnancy , Pregnancy Complications/drug therapy , Respiration Disorders/drug therapy , Sepsis/drug therapy , Thromboembolism/prevention & control , Thrombophilia/drug therapy , Thrombophilia/etiology
11.
N Engl J Med ; 385(8): 720-728, 2021 08 19.
Article in English | MEDLINE | ID: covidwho-1262030

ABSTRACT

The use of high-dose intravenous immune globulin (IVIG) plus anticoagulation is recommended for the treatment of vaccine-induced immune thrombotic thrombocytopenia (VITT), a rare side effect of adenoviral vector vaccines against coronavirus disease 2019 (Covid-19). We describe the response to IVIG therapy in three of the first patients in whom VITT was identified in Canada after the receipt of the ChAdOx1 nCoV-19 vaccine. The patients were between the ages of 63 and 72 years; one was female. At the time of this report, Canada had restricted the use of the ChAdOx1 nCoV-19 vaccine to persons who were 55 years of age or older on the basis of reports that VITT had occurred primarily in younger persons. Two of the patients in our study presented with limb-artery thrombosis; the third had cerebral venous and arterial thrombosis. Variable patterns of serum-induced platelet activation were observed in response to heparin and platelet factor 4 (PF4), indicating the heterogeneity of the manifestations of VITT in serum. After the initiation of IVIG, reduced antibody-induced platelet activation in serum was seen in all three patients. (Funded by the Canadian Institutes of Health Research.).


Subject(s)
COVID-19 Vaccines/adverse effects , Immunoglobulins, Intravenous , Thrombocytopenia/therapy , Thrombosis/therapy , Aged , Female , Fibrin Fibrinogen Degradation Products/analysis , Fibrinogen/analysis , Heparin/pharmacology , Humans , Male , Middle Aged , Platelet Count , Platelet Factor 4/pharmacology , Serotonin/blood , Thrombocytopenia/blood , Thrombocytopenia/etiology , Thrombosis/etiology , Thrombosis/immunology
12.
Cells ; 10(6)2021 06 07.
Article in English | MEDLINE | ID: covidwho-1259431

ABSTRACT

Coronaviruses such as SARS-CoV-2, which is responsible for COVID-19, depend on virus spike protein binding to host cell receptors to cause infection. The SARS-CoV-2 spike protein binds primarily to ACE2 on target cells and is then processed by membrane proteases, including TMPRSS2, leading to viral internalisation or fusion with the plasma membrane. It has been suggested, however, that receptors other than ACE2 may be involved in virus binding. We have investigated the interactions of recombinant versions of the spike protein with human epithelial cell lines that express low/very low levels of ACE2 and TMPRSS2 in a proxy assay for interaction with host cells. A tagged form of the spike protein containing the S1 and S2 regions bound in a temperature-dependent manner to all cell lines, whereas the S1 region alone and the receptor-binding domain (RBD) interacted only weakly. Spike protein associated with cells independently of ACE2 and TMPRSS2, while RBD required the presence of high levels of ACE2 for interaction. As the spike protein has previously been shown to bind heparin, a soluble glycosaminoglycan, we tested the effects of various heparins on ACE2-independent spike protein interaction with cells. Unfractionated heparin inhibited spike protein interaction with an IC50 value of <0.05 U/mL, whereas two low-molecular-weight heparins were less effective. A mutant form of the spike protein, lacking the arginine-rich putative furin cleavage site, interacted only weakly with cells and had a lower affinity for unfractionated and low-molecular-weight heparin than the wild-type spike protein. This suggests that the furin cleavage site might also be a heparin-binding site and potentially important for interactions with host cells. The glycosaminoglycans heparan sulphate and dermatan sulphate, but not chondroitin sulphate, also inhibited the binding of spike protein, indicating that it might bind to one or both of these glycosaminoglycans on the surface of target cells.


Subject(s)
Angiotensin-Converting Enzyme 2/physiology , Epithelial Cells/metabolism , Heparin/pharmacology , Spike Glycoprotein, Coronavirus/metabolism , A549 Cells , Angiotensin-Converting Enzyme 2/genetics , Animals , Binding Sites/drug effects , Binding Sites/genetics , Caco-2 Cells , Cell Line , Chlorocebus aethiops , Dermatan Sulfate/pharmacology , Down-Regulation/drug effects , Epithelial Cells/drug effects , Epithelial Cells/virology , Glycosaminoglycans/pharmacology , HEK293 Cells , HaCaT Cells , Heparitin Sulfate/pharmacology , Humans , Protein Binding/drug effects , Protein Binding/genetics , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/chemistry , Vero Cells , Virus Internalization/drug effects
13.
Molecules ; 26(11)2021 May 27.
Article in English | MEDLINE | ID: covidwho-1256613

ABSTRACT

Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is responsible for the coronavirus disease 2019 (COVID-19) global pandemic. The first step of viral infection is cell attachment, which is mediated by the binding of the SARS-CoV-2 receptor binding domain (RBD), part of the virus spike protein, to human angiotensin-converting enzyme 2 (ACE2). Therefore, drug repurposing to discover RBD-ACE2 binding inhibitors may provide a rapid and safe approach for COVID-19 therapy. Here, we describe the development of an in vitro RBD-ACE2 binding assay and its application to identify inhibitors of the interaction of the SARS-CoV-2 RBD to ACE2 by the high-throughput screening of two compound libraries (LOPAC®1280 and DiscoveryProbeTM). Three compounds, heparin sodium, aurintricarboxylic acid (ATA), and ellagic acid, were found to exert an effective binding inhibition, with IC50 values ranging from 0.6 to 5.5 µg/mL. A plaque reduction assay in Vero E6 cells infected with a SARS-CoV-2 surrogate virus confirmed the inhibition efficacy of heparin sodium and ATA. Molecular docking analysis located potential binding sites of these compounds in the RBD. In light of these findings, the screening system described herein can be applied to other drug libraries to discover potent SARS-CoV-2 inhibitors.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , Antiviral Agents/pharmacology , COVID-19/drug therapy , Drug Discovery , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Angiotensin-Converting Enzyme 2/genetics , Animals , Antiviral Agents/therapeutic use , Aurintricarboxylic Acid/pharmacology , Aurintricarboxylic Acid/therapeutic use , COVID-19/virology , Chlorocebus aethiops , Ellagic Acid/pharmacology , Ellagic Acid/therapeutic use , Heparin/pharmacology , Heparin/therapeutic use , High-Throughput Screening Assays , Humans , Inhibitory Concentration 50 , Molecular Docking Simulation , Protein Domains/genetics , Recombinant Proteins/genetics , Recombinant Proteins/metabolism , SARS-CoV-2/genetics , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Vero Cells , Virus Internalization/drug effects
14.
Life Sci ; 277: 119508, 2021 Jul 15.
Article in English | MEDLINE | ID: covidwho-1185152

ABSTRACT

Antiviral strategies for viruses that utilize proteoglycan core proteins (syndecans and glypicans) as receptors should focus on heparan sulfate (HS) biosynthesis rather than on inhibition of these sugar chains. Here, we show that heparin and certain xylosides, which exhibit in vitro viral entry inhibitory properties against HSV-1, HSV-2, HPV-16, HPV-31, HVB, HVC, HIV-1, HTLV-1, SARS-CoV-2, HCMV, DENV-1, and DENV-2, stimulated HS biosynthesis at the cell surface 2- to 3-fold for heparin and up to 10-fold for such xylosides. This is consistent with the hypothesis from a previous study that for core protein attachment, viruses are glycosylated at HS attachment sites (i.e., serine residues intended to receive the D-xylose molecule for initiating HS chains). Heparanase overexpression, endocytic entry, and syndecan shedding enhancement, all of which are observed during viral infection, lead to glycocalyx deregulation and appear to be direct consequences of this hypothesis. In addition to the appearance of type 2 diabetes and the degradation of HS observed during viral infection, we linked this hypothesis to that proposed in a previous publication.


Subject(s)
Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Biosynthetic Pathways/drug effects , Heparitin Sulfate/metabolism , Virus Internalization/drug effects , Animals , Drug Discovery , Glycosides/chemistry , Glycosides/pharmacology , Heparin/chemistry , Heparin/pharmacology , Humans , Virus Diseases/drug therapy
15.
Biomed Pharmacother ; 139: 111561, 2021 Jul.
Article in English | MEDLINE | ID: covidwho-1174103

ABSTRACT

Heparin is the earliest and most widely used anticoagulant and antithrombotic drug that is still used in a variety of clinical indications. Since it was discovered in 1916, after more than a century of repeated exploration, heparin has not been replaced by other drugs, but a great progress has been made in its basic research and clinical application. Besides anticoagulant and antithrombotic effects, heparin also has antitumor, anti-inflammatory, antiviral, and other pharmacological activities. It is widely used clinically in cardiovascular and cerebrovascular diseases, lung diseases, kidney diseases, cancer, etc., as the first anticoagulant medicine in COVID-19 exerts anticoagulant, anti-inflammatory and antiviral effects. At the same time, however, it also leads to a lot of adverse reactions, such as bleeding, thrombocytopenia, elevated transaminase, allergic reactions, and others. This article comprehensively reviews the modern research progress of heparin compounds; discusses the structure, preparation, and adverse reactions of heparin; emphasizes the pharmacological activity and clinical application of heparin; reveals the possible mechanism of the therapeutic effect of heparin in related clinical applications; provides evidence support for the clinical application of heparin; and hints on the significance of exploring the wider application fields of heparin.


Subject(s)
Anticoagulants/pharmacology , Anticoagulants/therapeutic use , Drugs, Essential , Fibrinolytic Agents/pharmacology , Fibrinolytic Agents/therapeutic use , Heparin/pharmacology , Heparin/therapeutic use , Animals , COVID-19/drug therapy , Cardiovascular Diseases/drug therapy , Cerebrovascular Disorders/drug therapy , Humans , Kidney Diseases/drug therapy , Lung Injury/drug therapy
16.
Life Sci ; 276: 119376, 2021 Jul 01.
Article in English | MEDLINE | ID: covidwho-1157590

ABSTRACT

The severe forms and worsened outcomes of COVID-19 (coronavirus disease 19) are closely associated with hypertension and cardiovascular disease. Endothelial cells express Angiotensin-Converting Enzyme 2 (ACE2), which is the entrance door for the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). The hallmarks of severe illness caused by SARS-CoV-2 infection are increased levels of IL-6, C-reactive protein, D-dimer, ferritin, neutrophilia and lymphopenia, pulmonary intravascular coagulopathy and microthrombi of alveolar capillaries. The endothelial glycocalyx, a proteoglycan- and glycoprotein-rich layer covering the luminal side of endothelial cells, contributes to vascular homeostasis. It regulates vascular tonus and permeability, prevents thrombosis, and modulates leukocyte adhesion and inflammatory response. We hypothesized that cytokine production and reactive oxygen species (ROS) generation associated with COVID-19 leads to glycocalyx degradation. A cohort of 20 hospitalized patients with a confirmed COVID-19 diagnosis and healthy subjects were enrolled in this study. Mechanisms associated with glycocalyx degradation in COVID-19 were investigated. Increased plasma concentrations of IL-6 and IL1-ß, as well as increased lipid peroxidation and glycocalyx components were detected in plasma from COVID-19 patients compared to plasma from healthy subjects. Plasma from COVID-19 patients induced glycocalyx shedding in cultured human umbilical vein endothelial cells (HUVECs) and disrupted redox balance. Treatment of HUVECs with low molecular weight heparin inhibited the glycocalyx perturbation. In conclusion, plasma from COVID-19 patients promotes glycocalyx shedding and redox imbalance in endothelial cells, and heparin treatment potentially inhibits glycocalyx disruption.


Subject(s)
COVID-19/blood , COVID-19/pathology , Glycocalyx/pathology , Heparin/pharmacology , Aged , Blood Coagulation Disorders/blood , Blood Coagulation Disorders/virology , COVID-19/metabolism , COVID-19 Testing , Case-Control Studies , Cell Adhesion/physiology , Endothelium, Vascular/metabolism , Female , Glycocalyx/metabolism , Glycocalyx/virology , Human Umbilical Vein Endothelial Cells , Humans , Interleukin-1beta/blood , Interleukin-6/blood , Male , Middle Aged , Oxidation-Reduction , SARS-CoV-2 , Thrombosis/metabolism
17.
Br J Pharmacol ; 178(3): 626-635, 2021 02.
Article in English | MEDLINE | ID: covidwho-1066635

ABSTRACT

BACKGROUND AND PURPOSE: Currently, there are no licensed vaccines and limited antivirals for the treatment of COVID-19. Heparin (delivered systemically) is currently used to treat anticoagulant anomalies in COVID-19 patients. Additionally, in the United Kingdom, Brazil and Australia, nebulised unfractionated heparin (UFH) is being trialled in COVID-19 patients as a potential treatment. A systematic comparison of the potential antiviral effect of various heparin preparations on live wild type SARS-CoV-2, in vitro, is needed. EXPERIMENTAL APPROACH: Seven different heparin preparations including UFH and low MW heparins (LMWH) of porcine or bovine origin were screened for antiviral activity against live SARS-CoV-2 (Australia/VIC01/2020) using a plaque inhibition assay with Vero E6 cells. Interaction of heparin with spike protein RBD was studied using differential scanning fluorimetry and the inhibition of RBD binding to human ACE2 protein using elisa assays was examined. KEY RESULTS: All the UFH preparations had potent antiviral effects, with IC50 values ranging between 25 and 41 µg·ml-1 , whereas LMWHs were less inhibitory by ~150-fold (IC50 range 3.4-7.8 mg·ml-1 ). Mechanistically, we observed that heparin binds and destabilizes the RBD protein and furthermore, we show heparin directly inhibits the binding of RBD to the human ACE2 protein receptor. CONCLUSION AND IMPLICATIONS: This comparison of clinically relevant heparins shows that UFH has significantly stronger SARS-CoV-2 antiviral activity compared to LMWHs. UFH acts to directly inhibit binding of spike protein to the human ACE2 protein receptor. Overall, the data strongly support further clinical investigation of UFH as a potential treatment for patients with COVID-19.


Subject(s)
Heparin/pharmacology , SARS-CoV-2/growth & development , Angiotensin-Converting Enzyme 2/metabolism , Animals , Antiviral Agents/pharmacology , COVID-19/drug therapy , Chlorocebus aethiops , Heparin/metabolism , Heparin/therapeutic use , Heparin, Low-Molecular-Weight/pharmacology , Protein Binding/drug effects , Spike Glycoprotein, Coronavirus/metabolism , Viral Plaque Assay
18.
Stem Cells Transl Med ; 10(6): 883-894, 2021 06.
Article in English | MEDLINE | ID: covidwho-1060671

ABSTRACT

While mesenchymal stromal cells are an appealing therapeutic option for a range of clinical applications, their potential to induce clotting when used systemically remains a safety concern, particularly in hypercoagulable conditions, such as in patients with severe COVID-19, trauma, or cancers. Here, we tested a novel preclinical approach aimed at improving the safety of mesenchymal stromal cell (MSC) systemic administration by use of a bioreactor. In this system, MSCs are seeded on the exterior of a hollow-fiber filter, sequestering them behind a hemocompatible semipermeable membrane with defined pore-size and permeability to allow for a molecularly defined cross talk between the therapeutic cells and the whole blood environment, including blood cells and signaling molecules. The potential for these bioreactor MSCs to induce clots in coagulable plasma was compared against directly injected "free" MSCs, a model of systemic administration. Our results showed that restricting MSCs exposure to plasma via a bioreactor extends the time necessary for clot formation to occur when compared with "free" MSCs. Measurement of cell surface data indicates the presence of known clot inducing factors, namely tissue factor and phosphatidylserine. Results also showed that recovering cells and flushing the bioreactor prior to use further prolonged clot formation time. Furthermore, application of this technology in two in vivo models did not require additional heparin in fully anticoagulated experimental animals to maintain target activated clotting time levels relative to heparin anticoagulated controls. Taken together the clinical use of bioreactor housed MSCs could offer a novel method to control systemic MSC exposure and prolong clot formation time.


Subject(s)
Bioreactors , COVID-19/therapy , Cell Culture Techniques/methods , Mesenchymal Stem Cell Transplantation/methods , Thrombosis/prevention & control , Animals , Anticoagulants/pharmacology , Blood Coagulation Tests , Bone Marrow Cells/cytology , Cells, Cultured , Dogs , Heparin/pharmacology , Humans , Male , Membranes, Artificial , Mesenchymal Stem Cells/cytology , Mesenchymal Stem Cells/metabolism , Myocardial Infarction/pathology , Myocardial Infarction/prevention & control , SARS-CoV-2 , Swine
19.
J Virol ; 95(3)2021 01 13.
Article in English | MEDLINE | ID: covidwho-1048660

ABSTRACT

Severe acute respiratory syndrome-related coronavirus 2 (SARS-CoV-2) has caused a pandemic of historic proportions and continues to spread globally, with enormous consequences to human health. Currently there is no vaccine, effective therapeutic, or prophylactic. As with other betacoronaviruses, attachment and entry of SARS-CoV-2 are mediated by the spike glycoprotein (SGP). In addition to its well-documented interaction with its receptor, human angiotensin-converting enzyme 2 (hACE2), SGP has been found to bind to glycosaminoglycans like heparan sulfate, which is found on the surface of virtually all mammalian cells. Here, we pseudotyped SARS-CoV-2 SGP on a third-generation lentiviral (pLV) vector and tested the impact of various sulfated polysaccharides on transduction efficiency in mammalian cells. The pLV vector pseudotyped SGP efficiently and produced high titers on HEK293T cells. Various sulfated polysaccharides potently neutralized pLV-S pseudotyped virus with clear structure-based differences in antiviral activity and affinity to SGP. Concentration-response curves showed that pLV-S particles were efficiently neutralized by a range of concentrations of unfractionated heparin (UFH), enoxaparin, 6-O-desulfated UFH, and 6-O-desulfated enoxaparin with 50% inhibitory concentrations (IC50s) of 5.99 µg/liter, 1.08 mg/liter, 1.77 µg/liter, and 5.86 mg/liter, respectively. In summary, several sulfated polysaccharides show potent anti-SARS-CoV-2 activity and can be developed for prophylactic as well as therapeutic purposes.IMPORTANCE The emergence of severe acute respiratory syndrome coronavirus (SARS-CoV-2) in Wuhan, China, in late 2019 and its subsequent spread to the rest of the world has created a pandemic situation unprecedented in modern history. While ACE2 has been identified as the viral receptor, cellular polysaccharides have also been implicated in virus entry. The SARS-CoV-2 spike glycoprotein (SGP) binds to glycosaminoglycans like heparan sulfate, which is found on the surface of virtually all mammalian cells. Here, we report structure-based differences in antiviral activity and affinity to SGP for several sulfated polysaccharides, including both well-characterized FDA-approved drugs and novel marine sulfated polysaccharides, which can be developed for prophylactic as well as therapeutic purposes.


Subject(s)
Antiviral Agents/pharmacology , Heparin/pharmacology , SARS-CoV-2/drug effects , Virus Internalization/drug effects , Animals , Antiviral Agents/chemistry , Antiviral Agents/metabolism , Drug Evaluation, Preclinical , Enoxaparin/chemistry , Enoxaparin/metabolism , Enoxaparin/pharmacology , Genetic Vectors/genetics , HEK293 Cells , Heparin/chemistry , Heparin/metabolism , Heparitin Sulfate/metabolism , Humans , Inhibitory Concentration 50 , Lentivirus/genetics , Molecular Structure , Molecular Weight , Polysaccharides/chemistry , Polysaccharides/metabolism , Polysaccharides/pharmacology , Protein Binding , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Transduction, Genetic , Virus Attachment/drug effects
20.
Food Chem Toxicol ; 148: 111974, 2021 Feb.
Article in English | MEDLINE | ID: covidwho-1009497

ABSTRACT

The coronavirus disease (COVID)-19 pandemic is a major challenge for the health systems worldwide. Acute respiratory distress syndrome (ARDS), is one of the most common complications of the COVID-19 infection. The activation of the coagulation system plays an important role in the pathogenesis of ARDS. The development of lung coagulopathy involves thrombin generation and fibrinolysis inhibition. Unfractionated heparin and its recently introduced counterpart low molecular weight heparin (LMWH), are widely used anticoagulants with a variety of clinical indications allowing for limited and manageable physio-toxicologic side effects while the use of protamine sulfate, heparin's effective antidote, has made their use even safer. Tissue-type plasminogen activator (tPA) is approved as intravenous thrombolytic treatment. The present narrative review discusses the use of heparin and tPA in the treatment of COVID-19-induced ARDS and their related potential physio-toxicologic side effects. The article is a quick review of articles on anticoagulation in COVID infection and the potential toxicologic reactions associated with these drugs.


Subject(s)
COVID-19/physiopathology , Hemostasis/drug effects , Heparin/therapeutic use , Thrombosis/complications , Tissue Plasminogen Activator/therapeutic use , Heparin/pharmacology , Humans , Tissue Plasminogen Activator/pharmacology
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