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1.
J Chem Inf Model ; 63(11): 3601-3613, 2023 06 12.
Article in English | MEDLINE | ID: covidwho-20232259

ABSTRACT

The SARS-CoV-2 main protease (Mpro) is a crucial enzyme for viral replication and has been considered an attractive drug target for the treatment of COVID-19. In this study, virtual screening techniques and in vitro assays were combined to identify novel Mpro inhibitors starting from around 8000 FDA-approved drugs. The docking analysis highlighted 17 promising best hits, biologically characterized in terms of their Mpro inhibitory activity. Among them, 7 cephalosporins and the oral anticoagulant betrixaban were able to block the enzyme activity in the micromolar range with no cytotoxic effect at the highest concentration tested. After the evaluation of the degree of conservation of Mpro residues involved in the binding with the studied ligands, the ligands' activity on SARS-CoV-2 replication was assessed. The ability of betrixaban to affect SARS-CoV-2 replication associated to its antithrombotic effect could pave the way for its possible use in the treatment of hospitalized COVID-19 patients.


Subject(s)
COVID-19 , Humans , SARS-CoV-2 , Antiviral Agents/pharmacology , Antiviral Agents/chemistry , Drug Repositioning , Ligands , Protease Inhibitors/pharmacology , Protease Inhibitors/chemistry , Molecular Docking Simulation , Molecular Dynamics Simulation
2.
Viruses ; 15(5)2023 05 09.
Article in English | MEDLINE | ID: covidwho-20237088

ABSTRACT

During the COVID-19 pandemic, drug repurposing represented an effective strategy to obtain quick answers to medical emergencies. Based on previous data on methotrexate (MTX), we evaluated the anti-viral activity of several DHFR inhibitors in two cell lines. We observed that this class of compounds showed a significant influence on the virus-induced cytopathic effect (CPE) partly attributed to the intrinsic anti-metabolic activity of these drugs, but also to a specific anti-viral function. To elucidate the molecular mechanisms, we took advantage of our EXSCALATE platform for in-silico molecular modelling and further validated the influence of these inhibitors on nsp13 and viral entry. Interestingly, pralatrexate and trimetrexate showed superior effects in counteracting the viral infection compared to other DHFR inhibitors. Our results indicate that their higher activity is due to their polypharmacological and pleiotropic profile. These compounds can thus potentially give a clinical advantage in the management of SARS-CoV-2 infection in patients already treated with this class of drugs.


Subject(s)
COVID-19 , SARS-CoV-2 , Humans , SARS-CoV-2/metabolism , Pandemics , Molecular Docking Simulation , Antiviral Agents/pharmacology , Antiviral Agents/metabolism , Drug Repositioning/methods
3.
Eur Heart J Digit Health ; 2(1): 171-174, 2021 Mar.
Article in English | MEDLINE | ID: covidwho-2318773

ABSTRACT

Aims: Following coronavirus disease (COVID-19) outbreak, the Italian government adopted strict rules of lockdown and social distancing. The aim of our study was to assess the admission rate for cardiac implantable electronic devices (CIEDs) replacement procedures in Campania, the 3rd-most-populous region of Italy, during COVID-19 lockdown. Methods and results: Data were sourced from 16 referral hospitals in Campania from 10 March to 4 May 2020 (lockdown period) and during the same period in 2019. We retrospectively evaluated consecutive patients hospitalized for CIEDs replacement procedures during the two observational periods. The number and type of CIEDs replacement procedures among patients followed by remote monitoring (RM), the admission rate, and the type of hospital admission between the two observational periods were compared. In total, 270 consecutive patients were hospitalized for CIEDs replacement procedures over the two observation periods. Overall CIEDs replacement procedures showed a reduction rate of 41.2% during COVID-19 lockdown. Patients were equally distributed for sex (P = 0.581), and both age [median 76 years (IQR: 68-83) vs. 79 years (IQR: 68-83); P = 0.497]. Cardiac implantable electronic devices replacement procedures in patients followed by RM significantly increased (IR: +211%; P < 0.001), mainly driven by the remarkable increase rate trend of both PM (IR: +475%; P < 0.001) and implantable cardiac defibrillator replacement procedures (IR: +67%, P = 0.01), during COVID-19 lockdown compared with 2019 timeframe. Conclusions: We showed a significant increase trend rate of replacement procedures among CIEDs patients followed by RM, suggesting the hypothesis of its increased use to closely monitoring and to optimize the hospital admission time during COVID-19 lockdown.

4.
Am J Community Psychol ; 2023 May 01.
Article in English | MEDLINE | ID: covidwho-2314362

ABSTRACT

This article explores the magnifying lenses of the COVID-19 syndemic to highlight how people racialized as migrants and refugees have been-and continue to be-disproportionally harmed. We use empirical evidence collected in our scholarly/activist work in Europe, Africa, South Asia, and the United States to examine migrant injustice as being produced by a combination of power structures and relations working to maintain colonial global orders and inequalities. This is what has been defined as "border imperialism." Our data, complemented by evidence from transnational solidarity groups, show that border imperialism has further intersected with the hygienic-sanitary logics of social control at play during the COVID-19 period. This intersection has resulted in increasingly coercive methods of restraining people on the move, as well as in increased-and new-forms of degradation of their lives, that is, an overall multiplication of border violences. At the same time, however, COVID-19 has provided a unique opportunity for grassroot solidarity initiatives and resistance led by people on the move to be amplified and extended. We conclude by emphasizing the need for community psychologists to take a more vigorous stance against oppressive border imperialist regimes and the related forms of violence they re/enact.

5.
Eur J Med Chem ; 244: 114853, 2022 Dec 15.
Article in English | MEDLINE | ID: covidwho-2301653

ABSTRACT

SARS-CoV-2 caused worldwide the current outbreak called COVID-19. Despite multiple countermeasures implemented, there is an urgent global need for new potent and efficient antiviral drugs against this pathogen. In this context, the main protease (Mpro) of SARS-CoV-2 is an essential viral enzyme and plays a pivotal role in viral replication and transcription. Its specific cleavage of polypeptides after a glutamine residue has been considered as a key element to design novel antiviral drugs. Herein, we reported the design, synthesis and structure-activity relationships of novel α-ketoamides as covalent reversible inhibitors of Mpro, exploiting the PADAM oxidation route. The reported compounds showed µM to nM activities in enzymatic and in the antiviral cell-based assays against SARS-CoV-2 Mpro. In order to assess inhibitors' binding mode, two co-crystal structures of SARS-CoV-2 Mpro in complex with our inhibitors were solved, which confirmed the covalent binding of the keto amide moiety to the catalytic Cys145 residue of Mpro. Finally, in order to interrogate potential broad-spectrum properties, we assessed a selection of compounds against MERS Mpro where they showed nM inhibitory potency, thus highlighting their potential as broad-spectrum coronavirus inhibitors.


Subject(s)
COVID-19 Drug Treatment , SARS-CoV-2 , Humans , Coronavirus 3C Proteases , Protease Inhibitors/pharmacology , Protease Inhibitors/chemistry , Viral Nonstructural Proteins , Cysteine Endopeptidases/metabolism , Antiviral Agents/pharmacology , Antiviral Agents/chemistry , Molecular Docking Simulation
6.
Eur J Med Chem ; 253: 115311, 2023 May 05.
Article in English | MEDLINE | ID: covidwho-2304178

ABSTRACT

Despite the approval of vaccines, monoclonal antibodies and restrictions during the pandemic, the demand for new efficacious and safe antivirals is compelling to boost the therapeutic arsenal against the COVID-19. The viral 3-chymotrypsin-like protease (3CLpro) is an essential enzyme for replication with high homology in the active site across CoVs and variants showing an almost unique specificity for Leu-Gln as P2-P1 residues, allowing the development of broad-spectrum inhibitors. The design, synthesis, biological activity, and cocrystal structural information of newly conceived peptidomimetic covalent reversible inhibitors are herein described. The inhibitors display an aldehyde warhead, a Gln mimetic at P1 and modified P2-P3 residues. Particularly, functionalized proline residues were inserted at P2 to stabilize the ß-turn like bioactive conformation, modulating the affinity. The most potent compounds displayed low/sub-nM potency against the 3CLpro of SARS-CoV-2 and MERS-CoV and inhibited viral replication of three human CoVs, i.e. SARS-CoV-2, MERS-CoV, and HCoV 229 in different cell lines. Particularly, derivative 12 exhibited nM-low µM antiviral activity depending on the virus, and the highest selectivity index. Some compounds were co-crystallized with SARS-CoV-2 3CLpro validating our design. Altogether, these results foster future work toward broad-spectrum 3CLpro inhibitors to challenge CoVs related pandemics.


Subject(s)
COVID-19 , Middle East Respiratory Syndrome Coronavirus , Peptidomimetics , Humans , SARS-CoV-2 , Protease Inhibitors/chemistry , Peptidomimetics/pharmacology , Peptidomimetics/chemistry , X-Rays , Peptide Hydrolases , Antiviral Agents/chemistry
7.
EMBO Mol Med ; 15(5): e17580, 2023 05 08.
Article in English | MEDLINE | ID: covidwho-2259755

ABSTRACT

Alongside vaccines, antiviral drugs are becoming an integral part of our response to the SARS-CoV-2 pandemic. Nirmatrelvir-an orally available inhibitor of the 3-chymotrypsin-like cysteine protease-has been shown to reduce the risk of progression to severe COVID-19. However, the impact of nirmatrelvir treatment on the development of SARS-CoV-2-specific adaptive immune responses is unknown. Here, by using mouse models of SARS-CoV-2 infection, we show that nirmatrelvir administration blunts the development of SARS-CoV-2-specific antibody and T cell responses. Accordingly, upon secondary challenge, nirmatrelvir-treated mice recruited significantly fewer memory T and B cells to the infected lungs and mediastinal lymph nodes, respectively. Together, the data highlight a potential negative impact of nirmatrelvir treatment with important implications for clinical management and might help explain the virological and/or symptomatic relapse after treatment completion reported in some individuals.


Subject(s)
COVID-19 , SARS-CoV-2 , Animals , Mice , Antibodies, Viral , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Lactams , Nitriles , Immunity
8.
ACS Med Chem Lett ; 13(5): 855-864, 2022 May 12.
Article in English | MEDLINE | ID: covidwho-1947205

ABSTRACT

A selection of compounds from a proprietary library, based on chemical diversity and various biological activities, was evaluated as potential inhibitors of the Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2) in a phenotypic-based screening assay. A compound based on a 2-phenylquinoline scaffold emerged as the most promising hit, with EC50 and CC50 values of 6 and 18 µM, respectively. The subsequent selection of additional analogues, along with the synthesis of ad hoc derivatives, led to compounds that maintained low µM activity as inhibitors of SARS-CoV-2 replication and lacked cytotoxicity at 100 µM. In addition, the most promising congeners also show pronounced antiviral activity against the human coronaviruses HCoV-229E and HCoV-OC43, with EC50 values ranging from 0.2 to 9.4 µM. The presence of a 6,7-dimethoxytetrahydroisoquinoline group at the C-4 position of the 2-phenylquinoline core gave compound 6g that showed potent activity against SARS-CoV-2 helicase (nsp13), a highly conserved enzyme, highlighting a potentiality against emerging HCoVs outbreaks.

9.
Sci Data ; 9(1): 405, 2022 07 13.
Article in English | MEDLINE | ID: covidwho-1931428

ABSTRACT

Worldwide, there are intensive efforts to identify repurposed drugs as potential therapies against SARS-CoV-2 infection and the associated COVID-19 disease. To date, the anti-inflammatory drug dexamethasone and (to a lesser extent) the RNA-polymerase inhibitor remdesivir have been shown to be effective in reducing mortality and patient time to recovery, respectively, in patients. Here, we report the results of a phenotypic screening campaign within an EU-funded project (H2020-EXSCALATE4COV) aimed at extending the repertoire of anti-COVID therapeutics through repurposing of available compounds and highlighting compounds with new mechanisms of action against viral infection. We screened 8702 molecules from different repurposing libraries, to reveal 110 compounds with an anti-cytopathic IC50 < 20 µM. From this group, 18 with a safety index greater than 2 are also marketed drugs, making them suitable for further study as potential therapies against COVID-19. Our result supports the idea that a systematic approach to repurposing is a valid strategy to accelerate the necessary drug discovery process.


Subject(s)
COVID-19 Drug Treatment , SARS-CoV-2 , Antiviral Agents/pharmacology , Antiviral Agents/therapeutic use , Drug Discovery , Drug Repositioning , Humans
10.
ACS Pharmacol Transl Sci ; 5(4): 226-239, 2022 Apr 08.
Article in English | MEDLINE | ID: covidwho-1852382

ABSTRACT

SARS-CoV-2 infection is still spreading worldwide, and new antiviral therapies are an urgent need to complement the approved vaccine preparations. SARS-CoV-2 nps13 helicase is a validated drug target participating in the viral replication complex and possessing two associated activities: RNA unwinding and 5'-triphosphatase. In the search of SARS-CoV-2 direct antiviral agents, we established biochemical assays for both SARS-CoV-2 nps13-associated enzyme activities and screened both in silico and in vitro a small in-house library of natural compounds. Myricetin, quercetin, kaempferol, and flavanone were found to inhibit the SARS-CoV-2 nps13 unwinding activity at nanomolar concentrations, while licoflavone C was shown to block both SARS-CoV-2 nps13 activities at micromolar concentrations. Mode of action studies showed that all compounds are nsp13 noncompetitive inhibitors versus ATP, while computational studies suggested that they can bind both nucleotide and 5'-RNA nsp13 binding sites, with licoflavone C showing a unique pattern of interaction with nsp13 amino acid residues. Overall, we report for the first time natural flavonoids as selective inhibitors of SARS-CoV-2 nps13 helicase with low micromolar activity.

11.
Int J Mol Sci ; 22(21)2021 Oct 29.
Article in English | MEDLINE | ID: covidwho-1488616

ABSTRACT

After almost two years from its first evidence, the COVID-19 pandemic continues to afflict people worldwide, highlighting the need for multiple antiviral strategies. SARS-CoV-2 main protease (Mpro/3CLpro) is a recognized promising target for the development of effective drugs. Because single target inhibition might not be sufficient to block SARS-CoV-2 infection and replication, multi enzymatic-based therapies may provide a better strategy. Here we present a structural and biochemical characterization of the binding mode of MG-132 to both the main protease of SARS-CoV-2, and to the human Cathepsin-L, suggesting thus an interesting scaffold for the development of double-inhibitors. X-ray diffraction data show that MG-132 well fits into the Mpro active site, forming a covalent bond with Cys145 independently from reducing agents and crystallization conditions. Docking of MG-132 into Cathepsin-L well-matches with a covalent binding to the catalytic cysteine. Accordingly, MG-132 inhibits Cathepsin-L with nanomolar potency and reversibly inhibits Mpro with micromolar potency, but with a prolonged residency time. We compared the apo and MG-132-inhibited structures of Mpro solved in different space groups and we identified a new apo structure that features several similarities with the inhibited ones, offering interesting perspectives for future drug design and in silico efforts.


Subject(s)
COVID-19 Drug Treatment , Cathepsin L/drug effects , Coronavirus 3C Proteases/drug effects , Leupeptins/chemistry , Leupeptins/pharmacology , SARS-CoV-2/chemistry , SARS-CoV-2/drug effects , Antiviral Agents/chemistry , Antiviral Agents/pharmacology , Catalytic Domain/drug effects , Cathepsin L/chemistry , Coronavirus 3C Proteases/chemistry , Drug Design , Drug Discovery , Humans , Molecular Docking Simulation , Molecular Dynamics Simulation , Peptidomimetics , Protein Binding , Protein Conformation , Protein Interaction Domains and Motifs , Virus Replication/drug effects , X-Ray Diffraction
12.
Plants (Basel) ; 10(10)2021 Oct 07.
Article in English | MEDLINE | ID: covidwho-1480919

ABSTRACT

In a search for natural compounds with anti-HIV-1 activity, we studied the effect of the ethanolic extract obtained from leaves, bark, and peels of Punica granatum L. for the inhibition of the HIV-1 reverse transcriptase (RT)-associated ribonuclease H (RNase H) and integrase (IN) LEDGF-dependent activities. The chemical analyses led to the detection of compounds belonging mainly to the phenolic and flavonoid chemical classes. Ellagic acid, flavones, and triterpenoid molecules were identified in leaves. The bark and peels were characterized by the presence of hydrolyzable tannins, such as punicalins and punicalagins, together with ellagic acid. Among the isolated compounds, the hydrolyzable tannins and ellagic acid showed a very high inhibition (IC50 values ranging from 0.12 to 1.4 µM and 0.065 to 0.09 µM of the RNase H and IN activities, respectively). Of the flavonoids, luteolin and apigenin were found to be able to inhibit RNase H and IN functions (IC50 values in the 3.7-22 µM range), whereas luteolin 7-O-glucoside showed selective activity for HIV-1 IN. In contrast, betulinic acid, ursolic acid, and oleanolic acid were selective for the HIV-1 RNase H activity. Our results strongly support the potential of non-edible P. granatum organs as a valuable source of anti-HIV-1 compounds.

14.
ACS Pharmacol Transl Sci ; 4(3): 1096-1110, 2021 Jun 11.
Article in English | MEDLINE | ID: covidwho-1313542

ABSTRACT

Compound repurposing is an important strategy for the identification of effective treatment options against SARS-CoV-2 infection and COVID-19 disease. In this regard, SARS-CoV-2 main protease (3CL-Pro), also termed M-Pro, is an attractive drug target as it plays a central role in viral replication by processing the viral polyproteins pp1a and pp1ab at multiple distinct cleavage sites. We here report the results of a repurposing program involving 8.7 K compounds containing marketed drugs, clinical and preclinical candidates, and small molecules regarded as safe in humans. We confirmed previously reported inhibitors of 3CL-Pro and have identified 62 additional compounds with IC50 values below 1 µM and profiled their selectivity toward chymotrypsin and 3CL-Pro from the Middle East respiratory syndrome virus. A subset of eight inhibitors showed anticytopathic effect in a Vero-E6 cell line, and the compounds thioguanosine and MG-132 were analyzed for their predicted binding characteristics to SARS-CoV-2 3CL-Pro. The X-ray crystal structure of the complex of myricetin and SARS-Cov-2 3CL-Pro was solved at a resolution of 1.77 Å, showing that myricetin is covalently bound to the catalytic Cys145 and therefore inhibiting its enzymatic activity.

15.
Viruses ; 12(7), 2020.
Article in English | MEDLINE | ID: covidwho-662134

ABSTRACT

HIV-1 infection requires life-long treatment and with 2.1 million new infections/year, faces the challenge of an increased rate of transmitted drug-resistant mutations. Therefore, a constant and timely effort is needed to identify new HIV-1 inhibitors active against drug-resistant variants. The ribonuclease H (RNase H) activity of HIV-1 reverse transcriptase (RT) is a very promising target, but to date, still lacks an efficient inhibitor. Here, we characterize the mode of action of N'-(2-hydroxy-benzylidene)-3,4,5-trihydroxybenzoylhydrazone (compound 13), an N-acylhydrazone derivative that inhibited viral replication (EC50 = 10 µM), while retaining full potency against the NNRTI-resistant double mutant K103N-Y181C virus. Time-of-addition and biochemical assays showed that compound 13 targeted the reverse-transcription step in cell-based assays and inhibited the RT-associated RNase H function, being >20-fold less potent against the RT polymerase activity. Docking calculations revealed that compound 13 binds within the RNase H domain in a position different from other selective RNase H inhibitors;site-directed mutagenesis studies revealed interactions with conserved amino acid within the RNase H domain, suggesting that compound 13 can be taken as starting point to generate a new series of more potent RNase H selective inhibitors active against circulating drug-resistant variants.

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