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1.
Int J Mol Sci ; 23(4)2022 Feb 11.
Article in English | MEDLINE | ID: covidwho-1715396

ABSTRACT

Interferon-ß (IFN-ß) is a pleiotropic cytokine secreted in response to various pathological conditions and is clinically used for therapy of multiple sclerosis. Its application for treatment of cancer, infections and pulmonary diseases is limited by incomplete understanding of regulatory mechanisms of its functioning. Recently, we reported that IFN-ß activity is affected by interactions with S100A1, S100A4, S100A6, and S100P proteins, which are members of the S100 protein family of multifunctional Ca2+-binding proteins possessing cytokine-like activities (Int J Mol Sci. 2020;21(24):9473). Here we show that IFN-ß interacts with one more representative of the S100 protein family, the S100B protein, involved in numerous oncological and neurological diseases. The use of chemical crosslinking, intrinsic fluorescence, and surface plasmon resonance spectroscopy revealed IFN-ß binding to Ca2+-loaded dimeric and monomeric forms of the S100B protein. Calcium depletion blocks the S100B-IFN-ß interaction. S100B monomerization increases its affinity to IFN-ß by 2.7 orders of magnitude (equilibrium dissociation constant of the complex reaches 47 pM). Crystal violet assay demonstrated that combined application of IFN-ß and S100B (5-25 nM) eliminates their inhibitory effects on MCF-7 cell viability. Bioinformatics analysis showed that the direct modulation of IFN-ß activity by the S100B protein described here could be relevant to progression of multiple oncological and neurological diseases.


Subject(s)
Interferon-beta/metabolism , S100 Calcium Binding Protein beta Subunit/metabolism , Animals , CHO Cells , Calcium/metabolism , Cell Line, Tumor , Cricetulus , Humans , MCF-7 Cells , Nervous System Diseases/metabolism , Protein Binding/physiology
2.
Nat Commun ; 13(1): 868, 2022 02 14.
Article in English | MEDLINE | ID: covidwho-1684025

ABSTRACT

SARS-CoV-2 infection is a major global public health concern with incompletely understood pathogenesis. The SARS-CoV-2 spike (S) glycoprotein comprises a highly conserved free fatty acid binding pocket (FABP) with unknown function and evolutionary selection advantage1,2. Deciphering FABP impact on COVID-19 progression is challenged by the heterogenous nature and large molecular variability of live virus. Here we create synthetic minimal virions (MiniVs) of wild-type and mutant SARS-CoV-2 with precise molecular composition and programmable complexity by bottom-up assembly. MiniV-based systematic assessment of S free fatty acid (FFA) binding reveals that FABP functions as an allosteric regulatory site enabling adaptation of SARS-CoV-2 immunogenicity to inflammation states via binding of pro-inflammatory FFAs. This is achieved by regulation of the S open-to-close equilibrium and the exposure of both, the receptor binding domain (RBD) and the SARS-CoV-2 RGD motif that is responsible for integrin co-receptor engagement. We find that the FDA-approved drugs vitamin K and dexamethasone modulate S-based cell binding in an FABP-like manner. In inflammatory FFA environments, neutralizing immunoglobulins from human convalescent COVID-19 donors lose neutralization activity. Empowered by our MiniV technology, we suggest a conserved mechanism by which SARS-CoV-2 dynamically couples its immunogenicity to the host immune response.


Subject(s)
COVID-19/immunology , Fatty Acids/immunology , SARS-CoV-2/immunology , Spike Glycoprotein, Coronavirus/immunology , Virion/immunology , A549 Cells , Allosteric Site/genetics , Amino Acid Sequence , Antibodies, Neutralizing/immunology , Antibodies, Viral/immunology , Binding Sites/genetics , COVID-19/metabolism , COVID-19/virology , Cells, Cultured , Cryoelectron Microscopy/methods , Electron Microscope Tomography/methods , Fatty Acid-Binding Proteins/immunology , Fatty Acid-Binding Proteins/metabolism , Fatty Acids/metabolism , Humans , MCF-7 Cells , Microscopy, Confocal/methods , Protein Binding , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Sequence Homology, Amino Acid , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Virion/metabolism , Virion/ultrastructure
3.
AAPS J ; 24(1): 8, 2021 12 06.
Article in English | MEDLINE | ID: covidwho-1555615

ABSTRACT

Lipidoid nanoparticles (LNPs) are the delivery platform in Onpattro, the first FDA-approved siRNA drug. LNPs are also the carriers in the Pfizer-BioNTech and Moderna COVID-19 mRNA vaccines. While these applications have demonstrated that LNPs effectively deliver nucleic acids to hepatic and muscle cells, it is unclear if LNPs could be used for delivery of siRNA to neural cells, which are notoriously challenging delivery targets. Therefore, the purpose of this study was to determine if LNPs could efficiently deliver siRNA to neurons. Because of their potential delivery utility in either applications for the central nervous system and the peripheral nervous system, we used both cortical neurons and sensory neurons. We prepared siRNA-LNPs using C12-200, a benchmark ionizable cationic lipidoid along with helper lipids. We demonstrated using dynamic light scattering that the inclusion of both siRNA and PEG-lipid provided a stabilizing effect to the LNP particle diameters and polydispersity indices by minimizing aggregation. We found that siRNA-LNPs were safely tolerated by primary dorsal root ganglion neurons. Flow cytometry analysis revealed that Cy5 siRNA delivered via LNPs into rat primary cortical neurons showed uptake levels similar to Lipofectamine RNAiMAX-the gold standard commercial transfection agent. However, LNPs demonstrated a superior safety profile, whereas the Lipofectamine-mediated uptake was concomitant with significant toxicity. Fluorescence microscopy demonstrated a time-dependent increase in the uptake of LNP-delivered Cy5 siRNA in a human cortical neuron cell line. Overall, our results suggest that LNPs are a viable platform that can be optimized for delivery of therapeutic siRNAs to neural cells.


Subject(s)
Ganglia, Spinal/metabolism , Lipids/chemistry , Nanoparticles , Neurons/metabolism , RNA, Small Interfering/administration & dosage , RNAi Therapeutics , Transfection , Animals , Carbocyanines/metabolism , Fluorescent Dyes/metabolism , Ganglia, Spinal/cytology , Humans , MCF-7 Cells , Microscopy, Fluorescence , Nanotechnology , Primary Cell Culture , RNA, Small Interfering/genetics , RNA, Small Interfering/metabolism , Rats , Time Factors
4.
Bioengineered ; 12(1): 4407-4419, 2021 12.
Article in English | MEDLINE | ID: covidwho-1373615

ABSTRACT

Widespread infection due to severe acute respiratory syndrome coronavirus 2 (SARS-CoV2) has led to a global pandemic. Currently, various approaches are being taken up to develop vaccines and therapeutics to treat SARS-CoV2 infection. Consequently, the S protein has become an important target protein for developing vaccines and therapeutics against SARS-CoV2. However, the highly infective nature of SARS-CoV2 restricts experimentation with the virus to highly secure BSL3 facilities. The availability of fusion-enabled, nonreplicating, and nonbiohazardous mimics of SARS-CoV2 virus fusion, containing the viral S or S and M protein in their native conformation on mammalian cells, can serve as a useful substitute for studying viral fusion for testing various inhibitors of viral fusion. This would avoid the use of the BSL3 facility for fusion studies required to develop therapeutics. In the present study, we have developed SARS-CoV2 virus fusion mimics (SCFMs) using mammalian cells transfected with constructs coding for S or S and M protein. The fusogenic property of the mimic(s) and their interaction with the functional human ACE2 receptors was confirmed experimentally. We have also shown that such mimics can easily be used in an inhibition assay. These mimic(s) can be easily prepared on a large scale, and such SCFMs can serve as an invaluable resource for viral fusion inhibition assays and in vitro screening of antiviral agents, which can be shared/handled between labs/facilities without worrying about any biohazard while working under routine laboratory conditions, avoiding the use of BSL3 laboratory.Abbreviations :SCFM: SARS-CoV2 Virus Fusion Mimic; ACE2: Angiotensin-Converting Enzyme 2; hACE2: Human Angiotensin-Converting enzyme 2; MEF: Mouse Embryonic Fibroblasts; HBSS: Hanks Balanced Salt Solution; FBS: Fetal Bovine Serum.


Subject(s)
Antibodies, Neutralizing/pharmacology , Containment of Biohazards/methods , SARS-CoV-2/genetics , Spike Glycoprotein, Coronavirus/antagonists & inhibitors , Viral Matrix Proteins/antagonists & inhibitors , Virus Internalization/drug effects , Angiotensin-Converting Enzyme 2/genetics , Angiotensin-Converting Enzyme 2/metabolism , Animals , Chlorocebus aethiops , Embryo, Mammalian , Fibroblasts/drug effects , Fibroblasts/virology , Gene Expression , Genes, Reporter , Green Fluorescent Proteins/genetics , Green Fluorescent Proteins/metabolism , HEK293 Cells , Humans , Luminescent Proteins/genetics , Luminescent Proteins/metabolism , MCF-7 Cells , Mice , Molecular Mimicry , Plasmids/chemistry , Plasmids/metabolism , Primary Cell Culture , Protein Binding , Receptors, Virus/genetics , Receptors, Virus/metabolism , SARS-CoV-2/drug effects , SARS-CoV-2/metabolism , Spike Glycoprotein, Coronavirus/genetics , Spike Glycoprotein, Coronavirus/metabolism , Transfection , Vero Cells , Viral Matrix Proteins/genetics , Viral Matrix Proteins/metabolism
5.
Int J Mol Sci ; 22(16)2021 Aug 20.
Article in English | MEDLINE | ID: covidwho-1367846

ABSTRACT

Coronavirus Disease 2019 (COVID-19) remains a global health crisis, despite the development and success of vaccines in certain countries. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the virus that causes COVID-19, uses its spike protein to bind to the human cell surface receptor angiotensin-converting enzyme 2 (ACE2), which allows the virus to enter the human body. Using our unique cell screening technology, we identified two ACE2-binding peptoid compounds and developed dimeric derivatives (ACE2P1D1 and ACE2P2D1) that effectively blocked spike protein-ACE2 interaction, resulting in the inhibition of SARS-CoV-2 pseudovirus entry into human cells. ACE2P1D1 and ACE2P2D1 also blocked infection by a D614G mutant pseudovirus. More importantly, these compounds do not decrease ACE2 expression nor its enzyme activity (which is important in normal blood pressure regulation), suggesting safe applicability in humans.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , COVID-19/prevention & control , Peptidyl-Dipeptidase A/metabolism , Peptoids/pharmacology , SARS-CoV-2/drug effects , Virus Internalization/drug effects , COVID-19/drug therapy , COVID-19/virology , Humans , MCF-7 Cells , Peptoids/metabolism , Protein Binding/drug effects , SARS-CoV-2/metabolism , SARS-CoV-2/physiology , Spike Glycoprotein, Coronavirus/metabolism
6.
Viruses ; 13(7)2021 06 29.
Article in English | MEDLINE | ID: covidwho-1289028

ABSTRACT

Vitis vinifera represents an important and renowned source of compounds with significant biological activity. Wines and winery bioproducts, such as grape pomace, skins, and seeds, are rich in bioactive compounds against a wide range of human pathogens, including bacteria, fungi, and viruses. However, little is known about the biological properties of vine leaves. The aim of this study was the evaluation of phenolic composition and antiviral activity of Vitis vinifera leaf extract against two human viruses: the Herpes simplex virus type 1 (HSV-1) and the pandemic and currently widespread severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2). About 40 phenolic compounds were identified in the extract by HPLC-MS/MS analysis: most of them were quercetin derivatives, others included derivatives of luteolin, kaempferol, apigenin, isorhamnetin, myricetin, chrysoeriol, biochanin, isookanin, and scutellarein. Leaf extract was able to inhibit both HSV-1 and SARS-CoV-2 replication in the early stages of infection by directly blocking the proteins enriched on the viral surface, at a very low concentration of 10 µg/mL. These results are very promising and highlight how natural extracts could be used in the design of antiviral drugs and the development of future vaccines.


Subject(s)
Antiviral Agents/pharmacology , Herpesvirus 1, Human/drug effects , Plant Extracts/pharmacology , Plant Leaves/chemistry , SARS-CoV-2/drug effects , Vitis/chemistry , A549 Cells , Animals , Biological Products/analysis , Biological Products/pharmacology , Cell Line , Chlorocebus aethiops , Chromatography, High Pressure Liquid , Humans , MCF-7 Cells , Phenols/pharmacology , Plant Extracts/analysis , Tandem Mass Spectrometry , Vero Cells
7.
Int J Biol Macromol ; 184: 297-312, 2021 Aug 01.
Article in English | MEDLINE | ID: covidwho-1265684

ABSTRACT

COVID-19 caused by SARS-CoV-2 corona virus has become a global pandemic. In the absence of drugs and vaccine, and premises of time, efforts and cost required for their development, natural resources such as herbs are anticipated to provide some help and may also offer a promising resource for drug development. Here, we have investigated the therapeutic prospective of Ashwagandha for the COVID-19 pandemic. Nine withanolides were tested in silico for their potential to target and inhibit (i) cell surface receptor protein (TMPRSS2) that is required for entry of virus to host cells and (ii) viral protein (the main protease Mpro) that is essential for virus replication. We report that the withanolides possess capacity to inhibit the activity of TMPRSS2 and Mpro. Furthermore, withanolide-treated cells showed downregulation of TMPRSS2 expression and inhibition of SARS-CoV-2 replication in vitro, suggesting that Ashwagandha may provide a useful resource for COVID-19 treatment.


Subject(s)
Antiviral Agents/pharmacology , Plant Extracts/chemistry , SARS-CoV-2/physiology , Serine Endopeptidases/metabolism , Viral Matrix Proteins/metabolism , Withanolides/pharmacology , A549 Cells , Antiviral Agents/chemistry , Cell Line , Cell Survival/drug effects , Computer Simulation , Down-Regulation , Gene Expression Regulation/drug effects , Humans , MCF-7 Cells , Models, Molecular , Molecular Dynamics Simulation , Protein Conformation , SARS-CoV-2/drug effects , Serine Endopeptidases/chemistry , Viral Matrix Proteins/chemistry , Virus Internalization/drug effects , Withanolides/chemistry
8.
J Extracell Vesicles ; 10(8): e12110, 2021 06.
Article in English | MEDLINE | ID: covidwho-1258076

ABSTRACT

Circulating nucleic acids, encapsulated within small extracellular vesicles (EVs), provide a remote cellular snapshot of biomarkers derived from diseased tissues, however selective isolation is critical. Current laboratory-based purification techniques rely on the physical properties of small-EVs rather than their inherited cellular fingerprints. We established a highly-selective purification assay, termed EV-CATCHER, initially designed for high-throughput analysis of low-abundance small-RNA cargos by next-generation sequencing. We demonstrated its selectivity by specifically isolating and sequencing small-RNAs from mouse small-EVs spiked into human plasma. Western blotting, nanoparticle tracking, and transmission electron microscopy were used to validate and quantify the capture and release of intact small-EVs. As proof-of-principle for sensitive detection of circulating miRNAs, we compared small-RNA sequencing data from a subset of small-EVs serum-purified with EV-CATCHER to data from whole serum, using samples from a small cohort of recently hospitalized Covid-19 patients. We identified and validated, only in small-EVs, hsa-miR-146a and hsa-miR-126-3p to be significantly downregulated with disease severity. Separately, using convalescent sera from recovered Covid-19 patients with high anti-spike IgG titers, we confirmed the neutralizing properties, against SARS-CoV-2 in vitro, of a subset of small-EVs serum-purified by EV-CATCHER, as initially observed with ultracentrifuged small-EVs. Altogether our data highlight the sensitivity and versatility of EV-CATCHER.


Subject(s)
Extracellular Vesicles/chemistry , Immunologic Techniques/methods , Animals , Bodily Secretions/chemistry , COVID-19/blood , COVID-19/physiopathology , Chlorocebus aethiops , Circulating MicroRNA , High-Throughput Nucleotide Sequencing , Humans , MCF-7 Cells , Mice , RAW 264.7 Cells , Severity of Illness Index , Vero Cells
9.
ACS Nano ; 15(1): 1167-1178, 2021 01 26.
Article in English | MEDLINE | ID: covidwho-1014984

ABSTRACT

Existing methods for RNA diagnostics, such as reverse transcription PCR (RT-PCR), mainly rely on nucleic acid amplification (NAA) and RT processes, which are known to introduce substantial issues, including amplification bias, cross-contamination, and sample loss. To address these problems, we introduce a confinement effect-inspired Cas13a assay for single-molecule RNA diagnostics, eliminating the need for NAA and RT. This assay involves confining the RNA-triggered Cas13a catalysis system in cell-like-sized reactors to enhance local concentrations of target and reporter simultaneously, via droplet microfluidics. It achieves >10 000-fold enhancement in sensitivity when compared to the bulk Cas13a assay and enables absolute digital single-molecule RNA quantitation. We experimentally demonstrate its broad applicability for precisely counting microRNAs, 16S rRNAs, and SARS-CoV-2 RNA from synthetic sequences to clinical samples with excellent accuracy. Notably, this direct RNA diagnostic technology enables detecting a wide range of RNA molecules at the single-molecule level. Moreover, its simplicity, universality, and excellent quantification capability might render it to be a dominant rival to RT-qPCR.


Subject(s)
CRISPR-Cas Systems , Microfluidics , RNA/analysis , Cell Line, Tumor , Enterococcus faecalis , Escherichia coli , Humans , Klebsiella pneumoniae , MCF-7 Cells , MicroRNAs/analysis , Pseudomonas aeruginosa , RNA, Ribosomal, 16S/analysis , Reverse Transcriptase Polymerase Chain Reaction , SARS-CoV-2/genetics , Staphylococcus aureus
10.
Arch Med Res ; 52(1): 48-57, 2021 01.
Article in English | MEDLINE | ID: covidwho-893598

ABSTRACT

BACKGROUND: Ras-GTPase activating protein SH3-domain-binding proteins (G3BP) are a small family of RNA-binding proteins implicated in regulating gene expression. Changes in expression of G3BPs are correlated to several cancers including thyroid, colon, pancreatic and breast cancer. G3BPs are important regulators of stress granule (SG) formation and function. SG are ribonucleoprotein (RNP) particles that respond to cellular stresses to triage mRNA resulting in transcripts being selectively degraded, stored or translated resulting in a change of gene expression which confers a survival response to the cell. These changes in gene expression contribute to the development of drug resistance. Many RNA viruses, including Chikungunya (and potentially Coronavirus), dismantle SG so that the cell cannot respond to the viral infection. Non-structural protein 3 (nsP3), from the Chikungunya virus, has been shown to translocate G3BP away from SG. Interestingly in cancer cells, the formation of SG is correlated to drug-resistance and blocking SG formation has been shown to reestablish the efficacy of the anticancer drug bortezomib. METHODS: Chikungunya nsP3 was transfected into breast cancer cell lines T47D and MCF7 to disrupt SG formation. Changes in the cytotoxicity of bortezomib were measured. RESULTS: Bortezomib cytotoxicity in breast cancer cell lines changed with a 22 fold decrease in its IC50 for T47D and a 7 fold decrease for MCF7 cells. CONCLUSIONS: Chikungunya nsP3 disrupts SG formation. As a result, it increases the cytotoxicity of the FDA approved drug, bortezomib. In addition, the increased cytotoxicity appears to correlate to improved bortezomib selectivity when compared to control cell lines.


Subject(s)
Bortezomib/pharmacology , Chikungunya Fever/drug therapy , Chikungunya virus/genetics , Cytoplasmic Granules/metabolism , DNA Helicases/metabolism , Poly-ADP-Ribose Binding Proteins/metabolism , RNA Helicases/metabolism , RNA Recognition Motif Proteins/metabolism , Viral Nonstructural Proteins/metabolism , Animals , Antineoplastic Agents/pharmacology , Breast Neoplasms/drug therapy , Breast Neoplasms/metabolism , Breast Neoplasms/pathology , Breast Neoplasms/therapy , Chikungunya Fever/metabolism , Chikungunya Fever/pathology , Chikungunya virus/metabolism , Chlorocebus aethiops , Cytoplasmic Granules/drug effects , Cytoplasmic Granules/pathology , DNA Helicases/genetics , Down-Regulation , Drug Resistance, Neoplasm , Female , HEK293 Cells , HeLa Cells , Humans , MCF-7 Cells , Poly-ADP-Ribose Binding Proteins/genetics , RNA Helicases/genetics , RNA Recognition Motif Proteins/genetics , Transfection , Vero Cells , Viral Nonstructural Proteins/administration & dosage , Viral Nonstructural Proteins/genetics
11.
J Cell Mol Med ; 24(21): 12864-12868, 2020 11.
Article in English | MEDLINE | ID: covidwho-780917

ABSTRACT

The SARS-coronavirus 2 is the aetiologic agent COVID-19. ACE2 has been identified as a cell entry receptor for the virus. Therefore, trying to understand how the gene is controlled has become a major goal. We silenced the expression of STAT3α and STAT3ß, and found that while silencing STAT3α causes an increase in ACE2 expression, silencing STAT3ß causes the opposite effect. Studying the role of STAT3 in ACE2 expression will shed light on the molecular events that contribute to the progression of the disease and that the different roles of STAT3α and STAT3ß in that context must be taken in consideration. Our results place STAT3 in line with additional potential therapeutic targets for treating COVID-19 patients.


Subject(s)
Angiotensin-Converting Enzyme 2/metabolism , STAT3 Transcription Factor/metabolism , Angiotensin-Converting Enzyme 2/genetics , Binding Sites , COVID-19 , Humans , MCF-7 Cells , Promoter Regions, Genetic , Protein Isoforms/genetics , Protein Isoforms/metabolism , SARS-CoV-2/drug effects , STAT3 Transcription Factor/genetics
12.
Mol Syst Biol ; 16(7): e9628, 2020 07.
Article in English | MEDLINE | ID: covidwho-707164

ABSTRACT

The COVID-19 pandemic caused by SARS-CoV-2 has is a global health challenge. Angiotensin-converting enzyme 2 (ACE2) is the host receptor for SARS-CoV-2 entry. Recent studies have suggested that patients with hypertension and diabetes treated with ACE inhibitors (ACEIs) or angiotensin receptor blockers have a higher risk of COVID-19 infection as these drugs could upregulate ACE2, motivating the study of ACE2 modulation by drugs in current clinical use. Here, we mined published datasets to determine the effects of hundreds of clinically approved drugs on ACE2 expression. We find that ACEIs are enriched for ACE2-upregulating drugs, while antineoplastic agents are enriched for ACE2-downregulating drugs. Vorinostat and isotretinoin are the top ACE2 up/downregulators, respectively, in cell lines. Dexamethasone, a corticosteroid used in treating severe acute respiratory syndrome and COVID-19, significantly upregulates ACE2 both in vitro and in vivo. Further top ACE2 regulators in vivo or in primary cells include erlotinib and bleomycin in the lung and vancomycin, cisplatin, and probenecid in the kidney. Our study provides leads for future work studying ACE2 expression modulators.


Subject(s)
Angiotensin Receptor Antagonists/pharmacology , Angiotensin-Converting Enzyme Inhibitors/pharmacology , Coronavirus Infections/drug therapy , Pneumonia, Viral/drug therapy , A549 Cells , Angiotensin-Converting Enzyme 2 , Betacoronavirus , Bleomycin/pharmacology , COVID-19 , Dexamethasone/pharmacology , Drug Design , Drug Evaluation, Preclinical , Erlotinib Hydrochloride/pharmacology , Fluphenazine/pharmacology , HEK293 Cells , Humans , Kidney/drug effects , Lung/drug effects , MCF-7 Cells , Pandemics , Peptidyl-Dipeptidase A , SARS-CoV-2 , Systems Biology , Up-Regulation , Vemurafenib/pharmacology
13.
J Biomol Struct Dyn ; 40(1): 1-13, 2022 01.
Article in English | MEDLINE | ID: covidwho-436584

ABSTRACT

Coronavirus disease 2019 (COVID-19) initiated in December 2019 in Wuhan, China and became pandemic causing high fatality and disrupted normal life calling world almost to a halt. Causative agent is a novel coronavirus called Severe Acute Respiratory Syndrome Coronavirus 2 (SARS-CoV-2/2019-nCoV). While new line of drug/vaccine development has been initiated world-wide, in the current scenario of high infected numbers, severity of the disease and high morbidity, repurposing of the existing drugs is heavily explored. Here, we used a homology-based structural model of transmembrane protease serine 2 (TMPRSS2), a cell surface receptor, required for entry of virus to the target host cell. Using the strengths of molecular docking and molecular dynamics simulations, we examined the binding potential of Withaferin-A (Wi-A), Withanone (Wi-N) and caffeic acid phenethyl ester to TPMRSS2 in comparison to its known inhibitor, Camostat mesylate. We found that both Wi-A and Wi-N could bind and stably interact at the catalytic site of TMPRSS2. Wi-N showed stronger interactions with TMPRSS2 catalytic residues than Wi-A and was also able to induce changes in its allosteric site. Furthermore, we investigated the effect of Wi-N on TMPRSS2 expression in MCF7 cells and found remarkable downregulation of TMPRSS2 mRNA in treated cells predicting dual action of Wi-N to block SARS-CoV-2 entry into the host cells. Since the natural compounds are easily available/affordable, they may even offer a timely therapeutic/preventive value for the management of SARS-CoV-2 pandemic. We also report that Wi-A/Wi-N content varies in different parts of Ashwagandha and warrants careful attention for their use.Communicated by Ramaswamy H. Sarma.


Subject(s)
SARS-CoV-2 , Serine Proteinase Inhibitors/pharmacology , Virus Internalization/drug effects , Withanolides/pharmacology , Binding Sites , COVID-19 , Humans , MCF-7 Cells , Molecular Docking Simulation , Plant Extracts/chemistry , Serine , Serine Endopeptidases/genetics
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