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1.
J Med Virol ; 2022 Feb 28.
Article in English | MEDLINE | ID: covidwho-1756615

ABSTRACT

Although vaccines are currently used to control the coronavirus disease 2019 (COVID-19) pandemic, treatment options are urgently needed for those who cannot be vaccinated and for future outbreaks involving new severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) strains or coronaviruses not covered by current vaccines. Thus far, few existing antivirals are known to be effective against SARS-CoV-2 and clinically successful against COVID-19. As part of an immediate response to the COVID-19 pandemic, a high-throughput, high content imaging-based SARS-CoV-2 infection assay was developed in VeroE6 African green monkey kidney epithelial cells expressing a stable enhanced green fluorescent protein (VeroE6-eGFP cells) and was used to screen a library of 5676 compounds that passed Phase 1 clinical trials. Eight drugs (nelfinavir, RG-12915, itraconazole, chloroquine, hydroxychloroquine, sematilide, remdesivir, and doxorubicin) were identified as inhibitors of in vitro anti-SARS-CoV-2 activity in VeroE6-eGFP and/or Caco-2 cell lines. However, apart from remdesivir, toxicity and pharmacokinetic data did not support further clinical development of these compounds for COVID-19 treatment.

2.
Int J Infect Dis ; 118: 126-131, 2022 Mar 02.
Article in English | MEDLINE | ID: covidwho-1712688

ABSTRACT

BACKGROUND: International travel poses the risk of importing SARS-CoV-2 infections and introducing new viral variants into the country of destination. Established measures include mandatory quarantine with the opportunity to abbreviate it with a negative rapid antigen test (RAT). METHODS: A total of 1,488 returnees were tested for SARS-CoV-2 with both PCR and RAT no earlier than 5 days after arrival. We assessed the sensitivity and specificity of the RAT. Positive samples were evaluated for infectivity in vitro in a cell culture outgrowth assay. We tracked if participants who tested negative were reported positive within 2 weeks of the initial test. RESULTS: Potential infectiousness was determined based on symptom onset analysis, resulting in a sensitivity of the antigen test of 89% in terms of infectivity. The specificity was 100%. All positive outgrowth assays were preceded by a positive RAT, indicating that all participants with proven in vitro infectivity were correctly identified. None of the negative participants tested positive during the follow-up. CONCLUSIONS: RAT no earlier than the 5th day after arrival was a reliable method for detecting infectious travellers and can be recommended as an appropriate method for managing SARS-CoV-2 travel restrictions. Compliance to the regulations and a high standard of test quality must be ensured.

3.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327354

ABSTRACT

ABSTRACT Although vaccines are currently used to control the coronavirus disease 2019 (COVID-19) pandemic, treatment options are urgently needed for those who cannot be vaccinated and for future outbreaks involving new severe acute respiratory syndrome coronavirus virus 2 (SARS-CoV-2) strains or coronaviruses not covered by current vaccines. Thus far, few existing antivirals are known to be effective against SARS-CoV-2 and clinically successful against COVID-19. As part of an immediate response to the COVID-19 pandemic, a high-throughput, high content imaging–based SARS-CoV-2 infection assay was developed in VeroE6-eGFP cells and was used to screen a library of 5676 compounds that passed phase 1 clinical trials. Eight candidates (nelfinavir, RG-12915, itraconazole, chloroquine, hydroxychloroquine, sematilide, remdesivir, and doxorubicin) with in vitro anti–SARS-CoV-2 activity in VeroE6-eGFP and/or Caco-2 cell lines were identified. However, apart from remdesivir, toxicity and pharmacokinetic data did not support further clinical development of these compounds for COVID-19 treatment.

4.
EuropePMC;
Preprint in English | EuropePMC | ID: ppcovidwho-327323

ABSTRACT

Pattern recognition receptors (PRRs) and interferons (IFNs) serve as essential antiviral defense against SARS-CoV-2, the causative agent of the COVID-19 pandemic. Type III IFN (IFN-lambda) exhibit cell-type specific and long-lasting functions in autoinflammation, tumorigenesis and antiviral defense. Here, we identify the deubiquitinating enzyme USP22 as central regulator of basal IFN-lambda secretion and SARS-CoV-2 infections in human intestinal epithelial cells (hIECs). USP22-deficient hIECs strongly upregulate genes involved in IFN signaling and viral defense, including numerous IFN-stimulated genes (ISGs), with increased secretion of IFN-lambda and enhanced STAT1 signaling, even in the absence of exogenous IFNs or viral infection. Interestingly, USP22 controls basal and cGAMP-induced STING activation and loss of STING reversed STAT activation and ISG and IFN-lambda expression. Intriguingly, USP22-deficient hIECs are protected against SARS-CoV-2 infection, viral replication and the formation of de novo infectious particles, in a STING-dependent manner. These findings reveal USP22 as central host regulator of STING and type III IFN signaling, with important implications for SARS-CoV-2 infection and antiviral defense.

5.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-321402

ABSTRACT

Main protease and papain-like protease (PLpro) are essential coronaviral enzymes required for polypeptide processing during viral maturation. PLpro additionally cleaves proteinous post-translational modifications from host proteins to evade anti-viral immune responses. Here, we provide biochemical, structural and functional characterizations of PLpro from SARS-CoV-2 (PLproCoV2) and reveal differences to that of SARS (PLproSARS) in controlling interferon (IFN) and NF-kB pathways. PLproCoV2 and PLproSARS share 83% sequence identity, yet they differ in their host substrate preferences: PLproCoV2 predominantly cleaves the ubiquitin-like protein ISG15 off from host proteins, while PLproSARS preferentially targets ubiquitin chains. The crystal structure of PLproCoV2 in complex with ISG15 explains the affinity and higher specificity through distinctive binding to ISG15’s unique amino-terminal ubiquitin-like domain, and enabled the identification of GRL-0617 as a non-covalent candidate inhibitor for PLproCoV2. In human cells, PLproCoV2 cleaves ISG15 from interferon responsive factor 3 (IRF3), blocks its nuclear translocation, and reduces type I interferon responses, whereas PLproSARS preferentially mediates deubiquitination of critical components of the NF-kB pathway. Pharmacological inhibition of PLproCoV2 blocks the virus-induced cytopathogenic effect upon infection with SARS-CoV-2, fosters the anti- viral interferon pathway and reduces viral release from infected cells. We propose that therapeutic targeting of PLproCoV2 can suppress SARS-CoV-2 infection and promote anti-viral immunity.

6.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-309977

ABSTRACT

To identify possible candidates for progression towards clinical studies against SARS-CoV-2, we screened a well-defined collection of 5632 compounds including 3488 compounds which have undergone clinical investigations (marketed drugs, phases 1 -3, and withdrawn) across 600 indications. Compounds were screened for their inhibition of viral induced cytotoxicity using the human epithelial colorectal adenocarcinoma cell line Caco-2 and a SARS-CoV-2 isolate. The primary screen of 5632 compounds gave 271 hits. A total of 64 compounds with IC50 <20 µM were identified, including 19 compounds with IC50 < 1 µM. Of this confirmed hit population, 90% have not yet been previously reported as active against SARS-CoV-2 in-vitro cell assays. Some 37 of the actives are launched drugs, 19 are in phases 1-3 and 10 pre-clinical. Several inhibitors were associated with modulation of host pathways including kinase signaling P53 activation, ubiquitin pathways and PDE activity modulation, with long chain acyl transferases were effective viral inhibitors.

7.
EuropePMC; 2020.
Preprint in English | EuropePMC | ID: ppcovidwho-307081

ABSTRACT

A novel coronavirus was recently discovered and termed SARS-CoV-2. Human infection can cause coronavirus disease 2019 (COVID-19), for which, at this point, over 80,000 cases resulting in over 2,500 deaths have been reported in over 40 countries. SARS-CoV-2 shows some similarities to other coronaviruses. However, treatment options and a cellular understanding of SARS-CoV-2 infection are lacking. Here we identify the host cell pathways modulated by SARS-CoV-19 infection and reveal that drugs targeting pathways prevent viral replication in human cells. We established a human cell culture model for infection with SARS-CoV-2 clinical isolate. Employing this system, we determined the SARS-CoV-2 infection profile by translatome and proteome proteomics at different times after infection.These analyses revealed that SARS-CoV-2 reshapes central cellular pathways, such as translation, splicing, carbon metabolism and nucleic acid metabolism. Small molecule inhibitors targeting these pathways were tested in cellular infection assays and prevented viral replication. Our results reveal the cellular infection profile of SARS-CoV-2 and led to the identification of drugs inhibiting viral replication. We anticipate our results to guide efforts to develop therapy options for COVID-19.Authors Denisa Bojkova, Kevin Klann, and Benjamin Koch contributed equally to this workData associated with the preprint has been made available on the authors' website.

9.
Int J Mol Sci ; 23(3)2022 Jan 19.
Article in English | MEDLINE | ID: covidwho-1625123

ABSTRACT

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


Subject(s)
Angiotensin-Converting Enzyme 2 , Anti-Inflammatory Agents, Non-Steroidal/pharmacology , COVID-19/genetics , Acetaminophen/pharmacology , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , COVID-19/metabolism , COVID-19/pathology , Caco-2 Cells , Disease Progression , Enzyme Activation/drug effects , Etoricoxib/pharmacology , Flurbiprofen/pharmacology , Gene Expression Regulation, Enzymologic/drug effects , Humans , Ibuprofen/pharmacology , Male , Mice , Mice, Inbred C57BL , SARS-CoV-2/drug effects , SARS-CoV-2/physiology , Virus Internalization/drug effects
10.
Nat Neurosci ; 24(11): 1522-1533, 2021 11.
Article in English | MEDLINE | ID: covidwho-1500484

ABSTRACT

Coronavirus disease 2019 (COVID-19) can damage cerebral small vessels and cause neurological symptoms. Here we describe structural changes in cerebral small vessels of patients with COVID-19 and elucidate potential mechanisms underlying the vascular pathology. In brains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals and animal models, we found an increased number of empty basement membrane tubes, so-called string vessels representing remnants of lost capillaries. We obtained evidence that brain endothelial cells are infected and that the main protease of SARS-CoV-2 (Mpro) cleaves NEMO, the essential modulator of nuclear factor-κB. By ablating NEMO, Mpro induces the death of human brain endothelial cells and the occurrence of string vessels in mice. Deletion of receptor-interacting protein kinase (RIPK) 3, a mediator of regulated cell death, blocks the vessel rarefaction and disruption of the blood-brain barrier due to NEMO ablation. Importantly, a pharmacological inhibitor of RIPK signaling prevented the Mpro-induced microvascular pathology. Our data suggest RIPK as a potential therapeutic target to treat the neuropathology of COVID-19.


Subject(s)
Blood-Brain Barrier/metabolism , Brain/metabolism , Coronavirus 3C Proteases/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Microvessels/metabolism , SARS-CoV-2/metabolism , Animals , Blood-Brain Barrier/pathology , Brain/pathology , Chlorocebus aethiops , Coronavirus 3C Proteases/genetics , Cricetinae , Female , Humans , Intracellular Signaling Peptides and Proteins/genetics , Male , Mesocricetus , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microvessels/pathology , SARS-CoV-2/genetics , Vero Cells
11.
Chemistry ; 27(71): 17928-17940, 2021 Dec 20.
Article in English | MEDLINE | ID: covidwho-1487453

ABSTRACT

The global spread of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has called for an urgent need for dedicated antiviral therapeutics. Metal complexes are commonly underrepresented in compound libraries that are used for screening in drug discovery campaigns, however, there is growing evidence for their role in medicinal chemistry. Based on previous results, we have selected more than 100 structurally diverse metal complexes for profiling as inhibitors of two relevant SARS-CoV-2 replication mechanisms, namely the interaction of the spike (S) protein with the ACE2 receptor and the papain-like protease PLpro . In addition to many well-established types of mononuclear experimental metallodrugs, the pool of compounds tested was extended to approved metal-based therapeutics such as silver sulfadiazine and thiomersal, as well as polyoxometalates (POMs). Among the mononuclear metal complexes, only a small number of active inhibitors of the S/ACE2 interaction was identified, with titanocene dichloride as the only strong inhibitor. However, among the gold and silver containing complexes many turned out to be very potent inhibitors of PLpro activity. Highly promising activity against both targets was noted for many POMs. Selected complexes were evaluated in antiviral SARS-CoV-2 assays confirming activity for gold complexes with N-heterocyclic carbene (NHC) or dithiocarbamato ligands, a silver NHC complex, titanocene dichloride as well as a POM compound. These studies might provide starting points for the design of metal-based SARS-CoV-2 antiviral agents.


Subject(s)
Antiviral Agents/pharmacology , Coronavirus Papain-Like Proteases/antagonists & inhibitors , SARS-CoV-2 , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Angiotensin-Converting Enzyme 2 , SARS-CoV-2/drug effects
12.
Nat Neurosci ; 24(11): 1522-1533, 2021 11.
Article in English | MEDLINE | ID: covidwho-1483143

ABSTRACT

Coronavirus disease 2019 (COVID-19) can damage cerebral small vessels and cause neurological symptoms. Here we describe structural changes in cerebral small vessels of patients with COVID-19 and elucidate potential mechanisms underlying the vascular pathology. In brains of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2)-infected individuals and animal models, we found an increased number of empty basement membrane tubes, so-called string vessels representing remnants of lost capillaries. We obtained evidence that brain endothelial cells are infected and that the main protease of SARS-CoV-2 (Mpro) cleaves NEMO, the essential modulator of nuclear factor-κB. By ablating NEMO, Mpro induces the death of human brain endothelial cells and the occurrence of string vessels in mice. Deletion of receptor-interacting protein kinase (RIPK) 3, a mediator of regulated cell death, blocks the vessel rarefaction and disruption of the blood-brain barrier due to NEMO ablation. Importantly, a pharmacological inhibitor of RIPK signaling prevented the Mpro-induced microvascular pathology. Our data suggest RIPK as a potential therapeutic target to treat the neuropathology of COVID-19.


Subject(s)
Blood-Brain Barrier/metabolism , Brain/metabolism , Coronavirus 3C Proteases/metabolism , Intracellular Signaling Peptides and Proteins/metabolism , Microvessels/metabolism , SARS-CoV-2/metabolism , Animals , Blood-Brain Barrier/pathology , Brain/pathology , Chlorocebus aethiops , Coronavirus 3C Proteases/genetics , Cricetinae , Female , Humans , Intracellular Signaling Peptides and Proteins/genetics , Male , Mesocricetus , Mice , Mice, Inbred C57BL , Mice, Knockout , Mice, Transgenic , Microvessels/pathology , SARS-CoV-2/genetics , Vero Cells
13.
PLoS One ; 16(10): e0258684, 2021.
Article in English | MEDLINE | ID: covidwho-1480452

ABSTRACT

AIMS: Patients with cardiovascular comorbidities have a significantly increased risk for a critical course of COVID-19. As the SARS-CoV2 virus enters cells via the angiotensin-converting enzyme receptor II (ACE2), drugs which interact with the renin angiotensin aldosterone system (RAAS) were suspected to influence disease severity. METHODS AND RESULTS: We analyzed 1946 consecutive patients with cardiovascular comorbidities or hypertension enrolled in one of the largest European COVID-19 registries, the Lean European Open Survey on SARS-CoV-2 (LEOSS) registry. Here, we show that angiotensin II receptor blocker intake is associated with decreased mortality in patients with COVID-19 [OR 0.75 (95% CI 0,59-0.96; p = 0.013)]. This effect was mainly driven by patients, who presented in an early phase of COVID-19 at baseline [OR 0,64 (95% CI 0,43-0,96; p = 0.029)]. Kaplan-Meier analysis revealed a significantly lower incidence of death in patients on an angiotensin receptor blocker (ARB) (n = 33/318;10,4%) compared to patients using an angiotensin-converting enzyme inhibitor (ACEi) (n = 60/348;17,2%) or patients who received neither an ACE-inhibitor nor an ARB at baseline in the uncomplicated phase (n = 90/466; 19,3%; p<0.034). Patients taking an ARB were significantly less frequently reaching the mortality predicting threshold for leukocytes (p<0.001), neutrophils (p = 0.002) and the inflammatory markers CRP (p = 0.021), procalcitonin (p = 0.001) and IL-6 (p = 0.049). ACE2 expression levels in human lung samples were not altered in patients taking RAAS modulators. CONCLUSION: These data suggest a beneficial effect of ARBs on disease severity in patients with cardiovascular comorbidities and COVID-19, which is linked to dampened systemic inflammatory activity.


Subject(s)
Angiotensin Receptor Antagonists/administration & dosage , COVID-19 , Hypertension , Registries , SARS-CoV-2/metabolism , Adult , Aged , Aged, 80 and over , Angiotensin-Converting Enzyme Inhibitors/administration & dosage , Biomarkers/blood , COVID-19/blood , COVID-19/drug therapy , COVID-19/mortality , Comorbidity , Disease-Free Survival , Female , Humans , Hypertension/blood , Hypertension/drug therapy , Hypertension/mortality , Inflammation/blood , Inflammation/drug therapy , Inflammation/mortality , Male , Middle Aged , Severity of Illness Index , Survival Rate
14.
Metabolites ; 11(10)2021 Oct 13.
Article in English | MEDLINE | ID: covidwho-1470929

ABSTRACT

SARS-CoV-2 is causing the coronavirus disease 2019 (COVID-19) pandemic, for which effective pharmacological therapies are needed. SARS-CoV-2 induces a shift of the host cell metabolism towards glycolysis, and the glycolysis inhibitor 2-deoxy-d-glucose (2DG), which interferes with SARS-CoV-2 infection, is under development for the treatment of COVID-19 patients. The glycolytic pathway generates intermediates that supply the non-oxidative branch of the pentose phosphate pathway (PPP). In this study, the analysis of proteomics data indicated increased transketolase (TKT) levels in SARS-CoV-2-infected cells, suggesting that a role is played by the non-oxidative PPP. In agreement, the TKT inhibitor benfooxythiamine (BOT) inhibited SARS-CoV-2 replication and increased the anti-SARS-CoV-2 activity of 2DG. In conclusion, SARS-CoV-2 infection is associated with changes in the regulation of the PPP. The TKT inhibitor BOT inhibited SARS-CoV-2 replication and increased the activity of the glycolysis inhibitor 2DG. Notably, metabolic drugs like BOT and 2DG may also interfere with COVID-19-associated immunopathology by modifying the metabolism of immune cells in addition to inhibiting SARS-CoV-2 replication. Hence, they may improve COVID-19 therapy outcomes by exerting antiviral and immunomodulatory effects.

15.
Curr Issues Mol Biol ; 43(3): 1212-1225, 2021 Sep 22.
Article in English | MEDLINE | ID: covidwho-1438531

ABSTRACT

The coronavirus SARS-CoV-2 is the cause of the ongoing COVID-19 pandemic. Most SARS-CoV-2 infections are mild or even asymptomatic. However, a small fraction of infected individuals develops severe, life-threatening disease, which is caused by an uncontrolled immune response resulting in hyperinflammation. However, the factors predisposing individuals to severe disease remain poorly understood. Here, we show that levels of CD47, which is known to mediate immune escape in cancer and virus-infected cells, are elevated in SARS-CoV-2-infected Caco-2 cells, Calu-3 cells, and air-liquid interface cultures of primary human bronchial epithelial cells. Moreover, SARS-CoV-2 infection increases SIRPalpha levels, the binding partner of CD47, on primary human monocytes. Systematic literature searches further indicated that known risk factors such as older age and diabetes are associated with increased CD47 levels. High CD47 levels contribute to vascular disease, vasoconstriction, and hypertension, conditions that may predispose SARS-CoV-2-infected individuals to COVID-19-related complications such as pulmonary hypertension, lung fibrosis, myocardial injury, stroke, and acute kidney injury. Hence, age-related and virus-induced CD47 expression is a candidate mechanism potentially contributing to severe COVID-19, as well as a therapeutic target, which may be addressed by antibodies and small molecules. Further research will be needed to investigate the potential involvement of CD47 and SIRPalpha in COVID-19 pathology. Our data should encourage other research groups to consider the potential relevance of the CD47/ SIRPalpha axis in their COVID-19 research.


Subject(s)
Antigens, Differentiation/metabolism , CD47 Antigen/metabolism , COVID-19/epidemiology , COVID-19/metabolism , Pandemics , Receptors, Immunologic/metabolism , SARS-CoV-2/metabolism , Severity of Illness Index , Signal Transduction/immunology , Blood Donors , Blotting, Western/methods , Bronchi/cytology , COVID-19/pathology , COVID-19/virology , Caco-2 Cells , Epithelial Cells/metabolism , Epithelial Cells/virology , Healthy Volunteers , Humans , Monocytes/metabolism , Monocytes/virology , Polymerase Chain Reaction/methods , RNA, Viral/genetics , SARS-CoV-2/genetics , SARS-CoV-2/isolation & purification
16.
Biomedicines ; 9(9)2021 Sep 17.
Article in English | MEDLINE | ID: covidwho-1430775

ABSTRACT

Pandemic SARS-CoV-2 causes a mild to severe respiratory disease called coronavirus disease 2019 (COVID-19). While control of the SARS-CoV-2 spread partly depends on vaccine-induced or naturally acquired protective herd immunity, antiviral strategies are still needed to manage COVID-19. Enisamium is an inhibitor of influenza A and B viruses in cell culture and clinically approved in countries of the Commonwealth of Independent States. In vitro, enisamium acts through metabolite VR17-04 and inhibits the activity of the influenza A virus RNA polymerase. Here we show that enisamium can inhibit coronavirus infections in NHBE and Caco-2 cells, and the activity of the SARS-CoV-2 RNA polymerase in vitro. Docking and molecular dynamics simulations provide insight into the mechanism of action and indicate that enisamium metabolite VR17-04 prevents GTP and UTP incorporation. Overall, these results suggest that enisamium is an inhibitor of SARS-CoV-2 RNA synthesis in vitro.

17.
Life (Basel) ; 11(8)2021 Aug 10.
Article in English | MEDLINE | ID: covidwho-1399330

ABSTRACT

Blood-pressure-lowering drugs are proposed to foster SARS-CoV-2 infection by pharmacological upregulation of angiotensin-converting enzyme 2 (ACE2), the binding partner of the virus spike (S) protein, located on the surface of the host cells. Conversely, it is postulated that angiotensin-renin system antagonists may prevent lung damage caused by SARS-CoV-2 infection, by reducing angiotensin II levels, which can induce permeability of lung endothelial barrier via its interaction with the AT1 receptor (AT1R). METHODS: We have investigated the influence of the ACE inhibitors (lisinopril, captopril) and the AT1 antagonists (telmisartan, olmesartan) on the level of ACE2 mRNA and protein expression as well as their influence on the cytopathic effect of SARS-CoV-2 and on the cell barrier integrity in a Caco-2 cell model. RESULTS: The drugs revealed no effect on ACE2 mRNA and protein expression. ACE inhibitors and AT1R antagonist olmesartan did not influence the infection rate of SARS-CoV-2 and were unable to prevent the SARS-CoV-2-induced cell barrier disturbance. A concentration of 25 µg/mL telmisartan significantly reduced the virus replication rate. CONCLUSION: ACE inhibitors and AT1R antagonist showed neither beneficial nor detrimental effects on SARS-CoV-2-infection and cell barrier integrity in vitro at pharmacologically relevant concentrations.

19.
Life (Basel) ; 11(8)2021 Aug 10.
Article in English | MEDLINE | ID: covidwho-1348665

ABSTRACT

Blood-pressure-lowering drugs are proposed to foster SARS-CoV-2 infection by pharmacological upregulation of angiotensin-converting enzyme 2 (ACE2), the binding partner of the virus spike (S) protein, located on the surface of the host cells. Conversely, it is postulated that angiotensin-renin system antagonists may prevent lung damage caused by SARS-CoV-2 infection, by reducing angiotensin II levels, which can induce permeability of lung endothelial barrier via its interaction with the AT1 receptor (AT1R). METHODS: We have investigated the influence of the ACE inhibitors (lisinopril, captopril) and the AT1 antagonists (telmisartan, olmesartan) on the level of ACE2 mRNA and protein expression as well as their influence on the cytopathic effect of SARS-CoV-2 and on the cell barrier integrity in a Caco-2 cell model. RESULTS: The drugs revealed no effect on ACE2 mRNA and protein expression. ACE inhibitors and AT1R antagonist olmesartan did not influence the infection rate of SARS-CoV-2 and were unable to prevent the SARS-CoV-2-induced cell barrier disturbance. A concentration of 25 µg/mL telmisartan significantly reduced the virus replication rate. CONCLUSION: ACE inhibitors and AT1R antagonist showed neither beneficial nor detrimental effects on SARS-CoV-2-infection and cell barrier integrity in vitro at pharmacologically relevant concentrations.

20.
J Biol Chem ; 297(2): 100925, 2021 08.
Article in English | MEDLINE | ID: covidwho-1336599

ABSTRACT

Apart from prevention using vaccinations, the management options for COVID-19 remain limited. In retrospective cohort studies, use of famotidine, a specific oral H2 receptor antagonist (antihistamine), has been associated with reduced risk of intubation and death in patients hospitalized with COVID-19. In a case series, nonhospitalized patients with COVID-19 experienced rapid symptom resolution after taking famotidine, but the molecular basis of these observations remains elusive. Here we show using biochemical, cellular, and functional assays that famotidine has no effect on viral replication or viral protease activity. However, famotidine can affect histamine-induced signaling processes in infected Caco2 cells. Specifically, famotidine treatment inhibits histamine-induced expression of Toll-like receptor 3 (TLR3) in SARS-CoV-2 infected cells and can reduce TLR3-dependent signaling processes that culminate in activation of IRF3 and the NF-κB pathway, subsequently controlling antiviral and inflammatory responses. SARS-CoV-2-infected cells treated with famotidine demonstrate reduced expression levels of the inflammatory mediators CCL-2 and IL6, drivers of the cytokine release syndrome that precipitates poor outcome for patients with COVID-19. Given that pharmacokinetic studies indicate that famotidine can reach concentrations in blood that suffice to antagonize histamine H2 receptors expressed in mast cells, neutrophils, and eosinophils, these observations explain how famotidine may contribute to the reduced histamine-induced inflammation and cytokine release, thereby improving the outcome for patients with COVID-19.


Subject(s)
Famotidine/pharmacology , Histamine Antagonists/pharmacology , SARS-CoV-2/drug effects , Toll-Like Receptor 3/metabolism , A549 Cells , Binding Sites , Caco-2 Cells , Chemokine CCL2/metabolism , Coronavirus 3C Proteases/metabolism , HeLa Cells , Humans , Interferon Regulatory Factor-3/metabolism , Interleukin-6/metabolism , Molecular Docking Simulation , NF-kappa B/metabolism , Protein Binding , SARS-CoV-2/physiology , Signal Transduction , Toll-Like Receptor 3/chemistry , Virus Replication
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