scholarly journals Targeted Drug Repurposing Against the SARS-CoV-2 E channel Identifies Blockers With in vitro Antiviral Activity

2021 ◽  
Author(s):  
Prabhat Pratap Singh Tomar ◽  
Miriam Krugliak ◽  
Isaiah Tuvia Arkin
Keyword(s):  
Tissue Culture ◽  
Ion Channels ◽  
Antiviral Activity ◽  
Viral Replication ◽  
Drug Repurposing ◽  
Viral Spread ◽  
E Protein ◽  
Human Use ◽  
The Impact

It is difficult to overstate the impact that COVID-19 had on humankind. The pandemic’s etiological agent, SARS-CoV-2, is a member of the Coronaviridae, and as such, is an enveloped virus with ion channels in its membrane. Therefore, in an attempt to provide an option to curb the viral spread, we searched for blockers of its E protein viro-porin. Using three bacteria-based assays, we identified eight compounds that exhibited activity after screening a library of ca. 3000 approved-for-human-use drugs. Reassuringly, analysis of viral replication in tissue culture indicated that most of the compounds could reduce infectivity to varying extents. In conclusion, targeting a particular channel in the virus for drug repurposing may increase our arsenal of treatment options to combat COVID-19 virulence.Significance StatementThe goal of our study was to expand the treatment arsenal against COVID-19. To that end, we have decided to focus on drug therapy, and as a target - the E protein, an ion channel in the virus. Ion channels as a family are excellent drug targets, but viral channels have been underexploited for pharmaceutical point intervention. To hasten future regulatory requirements and focus the chemical search space, we screened a library of ca. 3000 approved-for-human-use drugs using three independent bacteria-based assays. Our results yielded eight compounds, which were subsequently tested for antiviral activity in tissue culture. Gratifyingly, most compounds were able to reduce viral replication, and as such, both validate our approach and potentially augment our anti-COVID tool kit.

scholarly journals Identification of SARS-CoV-2 E Channel Blockers from a Repurposed Drug Library

2021 ◽  
Vol 14 (7) ◽  
pp. 604
Author(s):  
Prabhat Pratap Singh Tomar ◽  
Miriam Krugliak ◽  
Isaiah T. Arkin
Keyword(s):  
Ion Channels ◽  
In Vivo Studies ◽  
Channel Blockers ◽  
Exact Role ◽  
Enveloped Virus ◽  
Viral Spread ◽  
E Protein ◽  
Human Use

SARS-CoV-2, the etiological agent of the COVID-19 pandemic, is a member of the Coronaviridae family. It is an enveloped virus with ion channels in its membrane, the most characterized of which is the E protein. Therefore, in an attempt to identify blockers of the E channel, we screened a library of 2839 approved-for-human-use drugs. Our approach yielded eight compounds that exhibited appreciable activity in three bacteria-based channel assays. Considering the fact that the E channel is the most conserved of all SARS-CoV-2 proteins, any inhibitor of its activity may provide an option to curb the viral spread. In addition, inhibitors can also enhance our ability to understand the exact role played by the E protein during the infectivity cycle. Finally, detailed electrophysiological analyses, alongside in vitro and in vivo studies will be needed to establish the exact potential of each of the blockers identified in our study.

scholarly journals Broad anti-coronaviral activity of FDA approved drugs against SARS-CoV-2 in vitro and SARS-CoV in vivo

2020 ◽  
Author(s):  
Stuart Weston ◽  
Christopher M. Coleman ◽  
Rob Haupt ◽  
James Logue ◽  
Krystal Matthews ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Rapid Development ◽  
Drug Repurposing ◽  
Ic50 Values ◽  
Human Use ◽  
Approved Drugs ◽  
Fda Approved Drugs

AbstractSARS-CoV-2 emerged in China at the end of 2019 and has rapidly become a pandemic with roughly 2.7 million recorded COVID-19 cases and greater than 189,000 recorded deaths by April 23rd, 2020 (www.WHO.org). There are no FDA approved antivirals or vaccines for any coronavirus, including SARS-CoV-2. Current treatments for COVID-19 are limited to supportive therapies and off-label use of FDA approved drugs. Rapid development and human testing of potential antivirals is greatly needed. A quick way to test compounds with potential antiviral activity is through drug repurposing. Numerous drugs are already approved for human use and subsequently there is a good understanding of their safety profiles and potential side effects, making them easier to fast-track to clinical studies in COVID-19 patients. Here, we present data on the antiviral activity of 20 FDA approved drugs against SARS-CoV-2 that also inhibit SARS-CoV and MERS-CoV. We found that 17 of these inhibit SARS-CoV-2 at a range of IC50 values at non-cytotoxic concentrations. We directly follow up with seven of these to demonstrate all are capable of inhibiting infectious SARS-CoV-2 production. Moreover, we have evaluated two of these, chloroquine and chlorpromazine, in vivo using a mouse-adapted SARS-CoV model and found both drugs protect mice from clinical disease.

Interferon resistance of cutaneous T-cell lymphoma–derived clonal T-helper 2 cells allows selective viral replication

Blood ◽  
2001 ◽  
Vol 97 (2) ◽  
pp. 523-527 ◽  
Author(s):  
Reinhard Dummer ◽  
Udo Döbbeling ◽  
Ralf Geertsen ◽  
Jörg Willers ◽  
Günter Burg ◽  
...  
Keyword(s):  
T Cell ◽  
Viral Replication ◽  
Human Leukocyte ◽  
T Helper ◽  
Cd4 Cells ◽  
Efficient Treatment ◽  
T Helper 2 ◽  
Ifn Γ ◽  
The Impact

Abstract Cutaneous T-cell lymphomas (CTCL) comprise a heterogeneous group of lymphoproliferative disorders that are characterized by an accumulation of T-lymphocytes in the skin and occasionally in blood known as Sézary syndrome (SS). In most cases the dominant clone displays T-helper 2 cytokines. Because IFN-γ is a natural inhibitor of T-helper 2 cells and IFN-α is frequently used in CTCL, the impact of IFNs on SS-derived purified clonal T-helper 2 cells was studied using anti-Vβ antibodies. Moreover, IFNs are known to mediate virus resistance in normal cells. The isolated clonal CD4+ cells, but not the nonclonal CD4+ cells, appeared resistant to IFN-γ and IFN-α stimulation in terms of human leukocyte antigen up-regulation and MxA induction caused in part by alterations in Stat-1 molecule mRNA and IFNγR1 mRNA transcription. The IFN resistance of the patient-derived clonal cells was then targeted by vesicular stomatitis virus infection after IFN-α priming, resulting in selective viral replication in clonal cells. In contrast, nonclonal cells of the same patient showed IFN-dependent MxA expression, which is a major mediator protein of viral protection. The IFN resistance of the dominant T-helper 2 cells might be important for lymphomagenesis. Interferon signaling deficiencies can be targeted for purging patients' cells in vitro. Furthermore, this approach may allow specific molecular interventions, resulting in the efficient treatment of CTCL and other IFN-resistant neoplasms such as lung cancer.

scholarly journals Sensing through Non-Sensing Ocular Ion Channels

2020 ◽  
Vol 21 (18) ◽  
pp. 6925
Author(s):  
Meha Kabra ◽  
Bikash Ranjan Pattnaik
Keyword(s):  
Ion Channels ◽  
Visual Processing ◽  
Signal Transmission ◽  
Dominant Negative ◽  
Dominant Negative Effect ◽  
Cone Dystrophy ◽  
Wide Range ◽  
The Impact

Ion channels are membrane-spanning integral proteins expressed in multiple organs, including the eye. In the eye, ion channels are involved in various physiological processes, like signal transmission and visual processing. A wide range of mutations have been reported in the corresponding genes and their interacting subunit coding genes, which contribute significantly to an array of blindness, termed ocular channelopathies. These mutations result in either a loss- or gain-of channel functions affecting the structure, assembly, trafficking, and localization of channel proteins. A dominant-negative effect is caused in a few channels formed by the assembly of several subunits that exist as homo- or heteromeric proteins. Here, we review the role of different mutations in switching a “sensing” ion channel to “non-sensing,” leading to ocular channelopathies like Leber’s congenital amaurosis 16 (LCA16), cone dystrophy, congenital stationary night blindness (CSNB), achromatopsia, bestrophinopathies, retinitis pigmentosa, etc. We also discuss the various in vitro and in vivo disease models available to investigate the impact of mutations on channel properties, to dissect the disease mechanism, and understand the pathophysiology. Innovating the potential pharmacological and therapeutic approaches and their efficient delivery to the eye for reversing a “non-sensing” channel to “sensing” would be life-changing.

scholarly journals The human immunodeficiency virus-1 nef gene product: a positive factor for viral infection and replication in primary lymphocytes and macrophages.

1994 ◽  
Vol 179 (1) ◽  
pp. 101-113 ◽  
Author(s):  
M D Miller ◽  
M T Warmerdam ◽  
I Gaston ◽  
W C Greene ◽  
M B Feinberg
Keyword(s):  
Human Immunodeficiency Virus ◽  
Tissue Culture ◽  
Viral Replication ◽  
Gene Product ◽  
Mononuclear Cells ◽  
Positive Effects ◽  
Viral Spread ◽  
Immunodeficiency Virus ◽  
Hiv 1

Considerable controversy and uncertainty have surrounded the biological function of the Human Immunodeficiency Virus (HIV)-1 nef gene product. Initial studies suggested that this early, nonstructural viral protein functioned as a negative regulatory factor; thus, it was proposed to play a role in establishing or maintaining viral latency. In contrast, studies in Simian Immunodeficiency Virus (SIV)mac-infected rhesus monkeys have suggested that Nef is not a negative factor but rather plays a central role in promoting high-level viral replication and is required for viral pathogenesis in vivo. We sought to define a tissue culture system that would approximate the in vivo setting for virus infection in order to assess the role of HIV-1 Nef in viral replication. We show that infection of mitogen-activated peripheral blood mononuclear cells (PBMC) with Nef+ HIV results in enhanced replication as evidenced by earlier gag p24 expression when compared with infections performed with nef mutant viruses. Moreover, when unstimulated freshly isolated PBMC are infected with Nef+ and Nef- viruses and then subsequently activated with mitogen, the Nef-induced difference in viral replication kinetics is even more pronounced, with the Nef- viruses requiring much more time in culture for appreciable growth. A positive effect of Nef on viral replication was also observed in primary macrophages infected with a recombinant of YU-2, a patient-derived molecular clone with macrophage tropism. These positive effects of Nef on viral replication are dependent on the initial multiplicity of infection (MOI), in that infections of unstimulated PBMC at low MOI are most dependent upon intact nef for subsequent viral growth. We now provide evidence that the Nef+ HIV is more infectious than Nef- HIV from both a tissue culture infectious dose analysis, and a single-cell HIV infection assay. In the latter case, we demonstrate that infection with equivalent doses of HIV based on virion-associated gag p24 yields five- to sixfold more infected cells if Nef+ viral stocks were used. Furthermore, we find that the differential infectivity is not dependent on CD4 down-regulation as Nef+ virus produced from transfected COS cells lacking CD4 is also more infectious. However, normalization of PBMC infections to equivalent infectivity between that of the Nef+ and Nef- viruses continues to reveal delayed viral replication in the absence of Nef, suggesting that secondary viral spread in PBMC is also enhanced in Nef+ infections. We demonstrate this directly by showing a 13-15-fold increase in infectivity of PBMC-derived Nef+ HIC.(ABSTRACT TRUNCATED AT 400 WORDS)

scholarly journals EPSTI1 Is Involved in IL-28A-Mediated Inhibition of HCV Infection

2015 ◽  
Vol 2015 ◽  
pp. 1-13 ◽  
Author(s):  
Xianghe Meng ◽  
Darong Yang ◽  
Rong Yu ◽  
Haizhen Zhu
Keyword(s):  
Life Cycle ◽  
Antiviral Activity ◽  
Viral Replication ◽  
Virus Replication ◽  
Antiviral Effect ◽  
Vital Role ◽  
Hcv Infection ◽  
Rnase L ◽  
Interferon Treatment

It has been reported that IFN-λs inhibit HCV replication in vitro. But the mechanisms of how IL-28A conducts antiviral activity and the functions of IL-28A-induced ISGs (IFN-stimulated genes) are not fully understood. In this study, we found that IL-28A has the antiviral effect on HCV life cycle including viral replication, assembly, and release. IL-28A and IFN-αsynergistically inhibit virus replication. EPSTI1 (epithelial-stromal interaction 1), one of IL-28A-induced ISGs, plays a vital role in IL-28A-mediated antiviral activity. Furthermore, forced expression of EPSTI1 effectively inhibits HCV replication in the absence of interferon treatment, and knockdown of EPSTI1 contributes to viral enhancement. EPSTI1 can activate PKR promoter and induce several PKR-dependent genes, including IFN-β, IFIT1, OAS1, and RNase L, which is responsible for EPSTI1-mediated antiviral activity.

scholarly journals The α Chemokine, Interleukin 8, Inhibits the Antiviral Action of Interferon α

1997 ◽  
Vol 186 (7) ◽  
pp. 1077-1085 ◽  
Author(s):  
Khalid S.A. Khabar ◽  
Fahad Al-Zoghaibi ◽  
Mohammed N. Al-Ahdal ◽  
Tsugiya Murayama ◽  
Mohammed Dhalla ◽  
...  
Keyword(s):  
Antiviral Activity ◽  
Viral Replication ◽  
Early Stage ◽  
Encephalomyocarditis Virus ◽  
Early Gene ◽  
Interferon Α ◽  
Synthetase Activity ◽  
Dependent Manner ◽  
Oligoadenylate Synthetase

Interferon (IFN) exhibits a potent antiviral activity in vitro and plays a major role in the early defense against viruses. Like IFN, the proinflammatory chemokine, interleukin (IL)-8, is induced by viruses and appears in circulation during viral infections. In an in vitro cytopathic effect assay for IFN, we found that IL-8 can inhibit IFN-α activity in a dose-dependent manner. This action was reversed by specific monoclonal antibodies to IL-8. The chemokine was able to attenuate the IFN-mediated inhibition of viral replication as determined by measuring infectious virus yield. IL-8 also diminished the ability of IFN to inhibit an early stage of viral replication since IL-8 attenuated the inhibition of the formation of viral proteins. It appeared that IL-8 interfered with a late rather than an early step of IFN-mediated pathway such as early gene expression. The IL-8 inhibitory action on IFN-α antiviral activity was associated with reduced 2′,5′-A oligoadenylate synthetase activity, a pathway well correlative with the anti– encephalomyocarditis virus action of IFN-α. Understanding pathways that antagonize IFN action may lead to novel approaches to potentiate endogenous and therapeutic IFN.

scholarly journals Dual Inhibition of Human Rhinovirus 2A and 3C Proteases by Homophthalimides

1998 ◽  
Vol 42 (4) ◽  
pp. 916-920 ◽  
Author(s):  
Q. May Wang ◽  
Robert B. Johnson ◽  
Louis N. Jungheim ◽  
Jeffrey D. Cohen ◽  
Elcira C. Villarreal
Keyword(s):  
Antiviral Activity ◽  
Viral Replication ◽  
Enzyme Inhibitor ◽  
Antiviral Drug ◽  
3C Protease ◽  
Dependent Inhibition ◽  
Dual Inhibition ◽  
2A Protease

ABSTRACT The 2A and 3C proteases encoded by human rhinoviruses (HRVs) are attractive targets for antiviral drug development due to their important roles in viral replication. Homophthalimides were originally identified as inhibitors of rhinovirus 3C protease through our screening effort. Previous studies have indicated that the antiviral activity of certain homophthalimides exceeded their in vitro inhibitory activity against the viral 3C protease, suggesting that an additional mechanism might be involved. Reported here is the identification of homophthalimides as potent inhibitors for another rhinovirus protease, designated 2A. Several homophthalimides exhibit time-dependent inhibition of the 2A protease in the low-micromolar range, and enzyme-inhibitor complexes were identified by mass spectrometry. Compound LY343814, one of the most potent inhibitors against HRV14 2A protease, had an antiviral 50% inhibitory concentration of 4.2 μM in the cell-based assay. Our data reveal that homophthalimides are not only 3C but also 2A protease inhibitors in vitro, implying that the antiviral activity associated with these compounds might result from inactivation of both 2A and 3C proteases in vivo. Since the processing of the viral polyprotein is hierarchical, dual inhibition of the two enzymes may result in cooperative inhibition of viral replication. On the basis of the current understanding of their enzyme inhibitory mechanism, homophthalimides, as a group of novel nonpeptidic antirhinovirus agents, merit further structure-action relationship studies.

scholarly journals Colloidal aggregators in biochemical SARS-CoV-2 repurposing screens

2021 ◽  
Author(s):  
Henry R. O’Donnell ◽  
Tia A. Tummino ◽  
Conner Bardine ◽  
Charles S. Craik ◽  
Brian K. Shoichet
Keyword(s):  
Light Scattering ◽  
Drug Repurposing ◽  
Colloidal Aggregation ◽  
Biochemical Assays ◽  
Human Proteins ◽  
Approved Drugs ◽  
The Impact ◽  
Early Drug

AbstractTo fight the SARS-CoV-2 pandemic, much effort has been directed toward drug repurposing, testing investigational and approved drugs against several viral or human proteins in vitro. Here we investigate the impact of colloidal aggregation, a common artifact in early drug discovery, in these repurposing screens. We selected 56 drugs reported to be active in biochemical assays and tested them for aggregation by both dynamic light scattering and by enzyme counter screening with and without detergent; seventeen of these drugs formed colloids at concentrations similar to their literature reported IC50s. To investigate the occurrence of colloidal aggregators more generally in repurposing libraries, we further selected 15 drugs that had physical properties resembling known aggregators from a common repurposing library, and found that 6 of these aggregated at micromolar concentrations. An attraction of repurposing is that drugs active on one target are considered de-risked on another. This study suggests not only that many of the drugs repurposed for SARS-CoV-2 in biochemical assays are artifacts, but that, more generally, when screened at relevant concentrations, drugs can act artifactually via colloidal aggregation. Understanding the role of aggregation, and detecting its effects rapidly, will allow the community to focus on those drugs and leads that genuinely have potential for treating COVID-19.Abstract FigureTable of Contents Graphic

scholarly journals Effect of axenic culture and NAA in Vitro on masoyi (Cryptocarya massoy (Oken) Kosterm) seeds regeneration

2021 ◽  
Vol 914 (1) ◽  
pp. 012016
Author(s):  
Y Wibisono ◽  
A I Putri ◽  
Y Hadiyan ◽  
L Haryjanto ◽  
L Hakim ◽  
...  
Keyword(s):  
Tissue Culture ◽  
Germination Rate ◽  
Axenic Culture ◽  
Culture Method ◽  
Ms Medium ◽  
Controlled Conditions ◽  
Axenic Cultures ◽  
One Year ◽  
The Impact

Abstract The high valuable endemic commodities in Papua, Masoyi’s (Cryptocarya massoy) population facing great threat due to unsustainable harvest system. Generative propagation faces significant challenges due to seed characteristics and habitat conditions. Controlled conditions and the role of hormones have an important effect on generative growth. This study aimed to determine the influence of axenic culture with sterilization treatments Isothiazolone Biocide (IB) and 1-Naphtaleaneacetic Acid (NAA) in Murashige and Skoog (MS) medium on seed regeneration and to observe the development of seedlings at the acclimatization stage. The tissue culture method was used. The highest percentage of axenic cultures (57%) was obtained with 5% of BI. The germination rate of masoyi seeds was achieved by 100%. Furthermore, it showed varied responses depending upon concentrations of NAA, the addition of 1 ml l−1 NAA in MS medium is recommended. Acclimatization has been successfully carried out in the greenhouse (67% survival rate) and excellent seedlings growth at nursery (52.35 + 0.6 cm in height after one year transferred). The impact of the controlled conditions and the addition of NAA to axenic cultures in vitro increased the germination of masoyi seeds. Axenic culture and hormones were also important requirements for mass propagation of masoyi by tissue culture.

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