Inhibition of Polyamine Biosynthesis Is a Broad-Spectrum Strategy against RNA Viruses

ABSTRACT RNA viruses present an extraordinary threat to human health, given their sudden and unpredictable appearance, the potential for rapid spread among the human population, and their ability to evolve resistance to antiviral therapies. The recent emergence of chikungunya virus, Zika virus, and Ebola virus highlights the struggles to contain outbreaks. A significant hurdle is the availability of antivirals to treat the infected or protect at-risk populations. While several compounds show promise in vitro and in vivo , these outbreaks underscore the need to accelerate drug discovery. The replication of several viruses has been described to rely on host polyamines, small and abundant positively charged molecules found in the cell. Here, we describe the antiviral effects of two molecules that alter polyamine levels: difluoromethylornithine (DFMO; also called eflornithine), which is a suicide inhibitor of ornithine decarboxylase 1 (ODC1), and diethylnorspermine (DENSpm), an activator of spermidine/spermine N 1 -acetyltransferase (SAT1). We show that reducing polyamine levels has a negative effect on diverse RNA viruses, including several viruses involved in recent outbreaks, in vitro and in vivo . These findings highlight the importance of the polyamine biosynthetic pathway to viral replication, as well as its potential as a target in the development of further antivirals or currently available molecules, such as DFMO. IMPORTANCE RNA viruses present a significant hazard to human health, and combatting these viruses requires the exploration of new avenues for targeting viral replication. Polyamines, small positively charged molecules within the cell, have been demonstrated to facilitate infection for a few different viruses. Our study demonstrates that diverse RNA viruses rely on the polyamine pathway for replication and highlights polyamine biosynthesis as a promising drug target.

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Polyamine Depletion Abrogates Enterovirus Cellular Attachment

Journal of Virology ◽

10.1128/jvi.01054-19 ◽

2019 ◽

Vol 93 (20) ◽

Cited By ~ 5

Author(s):

Thomas M. Kicmal ◽

Patrick M. Tate ◽

Courtney N. Dial ◽

Jeremy J. Esin ◽

Bryan C. Mounce

Keyword(s):

Rna Viruses ◽

Severe Disease ◽

Coxsackievirus B3 ◽

Human Pathogens ◽

Polyamine Biosynthesis ◽

Virus Attachment ◽

Significant Public Health ◽

Approved Drugs

ABSTRACT Polyamines are small polycationic molecules with flexible carbon chains that are found in all eukaryotic cells. Polyamines are involved in the regulation of many host processes and have been shown to be implicated in viral replication. Depletion of polyamine pools in cells treated with FDA-approved drugs restricts replication of diverse RNA viruses. Viruses can exploit host polyamines to facilitate nucleic acid packaging, transcription, and translation, but other mechanisms remain largely unknown. Picornaviruses, including Coxsackievirus B3 (CVB3), are sensitive to the depletion of polyamines and remain a significant public health threat. We employed CVB3 as a model system to investigate a potential proviral role for polyamines using a forward screen. Passaging CVB3 in polyamine-depleted cells generated a mutation in capsid protein VP3 at residue 234. We show that this mutation confers resistance to polyamine depletion. Through attachment assays, we demonstrate that polyamine depletion limits CVB3 attachment to susceptible cells, which is rescued by incubating virus with polyamines. Furthermore, the capsid mutant rescues this inhibition in polyamine-depleted cells. More divergent viruses also exhibited reduced attachment to polyamine-depleted cells, suggesting that polyamines may facilitate attachment of diverse RNA viruses. These studies inform additional mechanisms of action for polyamine-depleting pharmaceuticals, with implications for potential antiviral therapies. IMPORTANCE Enteroviruses are significant human pathogens that can cause severe disease. These viruses rely on polyamines, small positively charged molecules, for robust replication, and polyamine depletion limits infection in vitro and in vivo. The mechanisms by which polyamines enhance enteroviral replication are unknown. Here, we describe how Coxsackievirus B3 (CVB3) utilizes polyamines to attach to susceptible cells and initiate infection. Using a forward genetic screen, we identified a mutation in a receptor-binding amino acid that promotes infection of polyamine-depleted cells. These data suggest that pharmacologically inhibiting polyamine biosynthesis may combat virus infection by preventing virus attachment to susceptible cells.

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Novel and potent inhibitors targeting DHODH are broad-spectrum antivirals against RNA viruses including newly-emerged coronavirus SARS-CoV-2

Protein & Cell ◽

10.1007/s13238-020-00768-w ◽

2020 ◽

Vol 11 (10) ◽

pp. 723-739 ◽

Cited By ~ 10

Author(s):

Rui Xiong ◽

Leike Zhang ◽

Shiliang Li ◽

Yuan Sun ◽

Minyi Ding ◽

...

Keyword(s):

Broad Spectrum ◽

Influenza A ◽

Ebola Virus ◽

Rna Viruses ◽

The Novel ◽

Knock Out ◽

Infected Cells ◽

Virus Zika ◽

Novel Coronavirus

Abstract Emerging and re-emerging RNA viruses occasionally cause epidemics and pandemics worldwide, such as the on-going outbreak of the novel coronavirus SARS-CoV-2. Herein, we identified two potent inhibitors of human DHODH, S312 and S416, with favorable drug-likeness and pharmacokinetic profiles, which all showed broad-spectrum antiviral effects against various RNA viruses, including influenza A virus, Zika virus, Ebola virus, and particularly against SARS-CoV-2. Notably, S416 is reported to be the most potent inhibitor so far with an EC50 of 17 nmol/L and an SI value of 10,505.88 in infected cells. Our results are the first to validate that DHODH is an attractive host target through high antiviral efficacy in vivo and low virus replication in DHODH knock-out cells. This work demonstrates that both S312/S416 and old drugs (Leflunomide/Teriflunomide) with dual actions of antiviral and immuno-regulation may have clinical potentials to cure SARS-CoV-2 or other RNA viruses circulating worldwide, no matter such viruses are mutated or not.

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Bioavailability Evaluation of Perchlorate in Different Foods In Vivo: Comparison with In Vitro Assays and Implications for Human Health Risk Assessment

Journal of Agricultural and Food Chemistry ◽

10.1021/acs.jafc.1c00539 ◽

2021 ◽

Author(s):

Xin Liu ◽

Hu Zhang ◽

Yimei Tian ◽

Min Fang ◽

Lin Xu ◽

...

Keyword(s):

Risk Assessment ◽

Health Risk ◽

Human Health ◽

Health Risk Assessment ◽

Human Health Risk ◽

Human Health Risk Assessment ◽

In Vitro Assays

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Plant-Derived Extracellular Vesicles: Current Findings,Challenges, and Future Applications

Membranes ◽

10.3390/membranes11060411 ◽

2021 ◽

Vol 11 (6) ◽

pp. 411

Author(s):

Nader Kameli ◽

Anya Dragojlovic-Kerkache ◽

Paul Savelkoul ◽

Frank R. Stassen

Keyword(s):

Human Health ◽

Extracellular Vesicles ◽

Preliminary Results ◽

In Vivo Experiments ◽

Health And Disease ◽

Conducting Research ◽

Protocol Standardization ◽

Insight Into

In recent years, plant-derived extracellular vesicles (PDEVs) have gained the interest of many experts in fields such as microbiology and immunology, and research in this field has exponentially increased. These nano-sized particles have provided researchers with a number of interesting findings, making their application in human health and disease very promising. Both in vitro and in vivo experiments have shown that PDEVs can exhibit a multitude of effects, suggesting that these vesicles may have many potential future applications, including therapeutics and nano-delivery of compounds. While the preliminary results are promising, there are still some challenges to face, such as a lack of protocol standardization, as well as knowledge gaps that need to be filled. This review aims to discuss various aspects of PDEV knowledge, including their preliminary findings, challenges, and future uses, giving insight into the complexity of conducting research in this field.

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Effects of Size and Surface Properties of Nanodiamonds on the Immunogenicity of Plant-Based H5 Protein of A/H5N1 Virus in Mice

Nanomaterials ◽

10.3390/nano11061597 ◽

2021 ◽

Vol 11 (6) ◽

pp. 1597

Author(s):

Thuong Thi Ho ◽

Van Thi Pham ◽

Tra Thi Nguyen ◽

Vy Thai Trinh ◽

Tram Vi ◽

...

Keyword(s):

High Pressure ◽

Neutralizing Antibodies ◽

H5n1 Virus ◽

Vaccine Development ◽

Particle Characterization ◽

Innovative Strategy ◽

Specific Igg ◽

Positively Charged

Nanodiamond (ND) has recently emerged as a potential nanomaterial for nanovaccine development. Here, a plant-based haemagglutinin protein (H5.c2) of A/H5N1 virus was conjugated with detonation NDs (DND) of 3.7 nm in diameter (ND4), and high-pressure and high-temperature (HPHT) oxidative NDs of ~40–70 nm (ND40) and ~100–250 nm (ND100) in diameter. Our results revealed that the surface charge, but not the size of NDs, is crucial to the protein conjugation, as well as the in vitro and in vivo behaviors of H5.c2:ND conjugates. Positively charged ND4 does not effectively form stable conjugates with H5.c2, and has no impact on the immunogenicity of the protein both in vitro and in vivo. In contrast, the negatively oxidized NDs (ND40 and ND100) are excellent protein antigen carriers. When compared to free H5.c2, H5.c2:ND40, and H5.c2:ND100 conjugates are highly immunogenic with hemagglutination titers that are both 16 times higher than that of the free H5.c2 protein. Notably, H5.c2:ND40 and H5.c2:ND100 conjugates induce over 3-folds stronger production of both H5.c2-specific-IgG and neutralizing antibodies against A/H5N1 than free H5.c2 in mice. These findings support the innovative strategy of using negatively oxidized ND particles as novel antigen carriers for vaccine development, while also highlighting the importance of particle characterization before use.

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The Multifunctional Sactipeptide Ruminococcin C1 Displays Potent Antibacterial Activity In Vivo as Well as Other Beneficial Properties for Human Health

International Journal of Molecular Sciences ◽

10.3390/ijms22063253 ◽

2021 ◽

Vol 22 (6) ◽

pp. 3253

Author(s):

Clarisse Roblin ◽

Steve Chiumento ◽

Cédric Jacqueline ◽

Eric Pinloche ◽

Cendrine Nicoletti ◽

...

Keyword(s):

Antibacterial Activity ◽

Human Health ◽

Biological Activities ◽

Resistant Bacteria ◽

Modified Peptides ◽

The 1960S ◽

Conventional Antibiotics ◽

Clinical Potential

The world is on the verge of a major antibiotic crisis as the emergence of resistant bacteria is increasing, and very few novel molecules have been discovered since the 1960s. In this context, scientists have been exploring alternatives to conventional antibiotics, such as ribosomally synthesized and post-translationally modified peptides (RiPPs). Interestingly, the highly potent in vitro antibacterial activity and safety of ruminococcin C1, a recently discovered RiPP belonging to the sactipeptide subclass, has been demonstrated. The present results show that ruminococcin C1 is efficient at curing infection and at protecting challenged mice from Clostridium perfringens with a lower dose than the conventional antibiotic vancomycin. Moreover, antimicrobial peptide (AMP) is also effective against this pathogen in the complex microbial community of the gut environment, with a selective impact on a few bacterial genera, while maintaining a global homeostasis of the microbiome. In addition, ruminococcin C1 exhibits other biological activities that could be beneficial for human health, as well as other fields of applications. Overall, this study, by using an in vivo infection approach, confirms the antimicrobial clinical potential and highlights the multiple functional properties of ruminococcin C1, thus extending its therapeutic interest.

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Effect of the cholesterol content of small unilamellar liposomes on their stability in vivo and in vitro

Biochemical Journal ◽

10.1042/bj1860591 ◽

1980 ◽

Vol 186 (2) ◽

pp. 591-598 ◽

Cited By ~ 398

Author(s):

Christopher Kirby ◽

Jacqui Clarke ◽

Gregory Gregoriadis

Keyword(s):

Blood Plasma ◽

Intravenous Injection ◽

Whole Blood ◽

Cholesterol Content ◽

Molar Ratio ◽

Phosphatidylcholine Liposomes ◽

Effective Use ◽

Positively Charged

Small unilamellar neutral, negatively and positively charged liposomes composed of egg phosphatidylcholine, various amounts of cholesterol and, when appropriate, phosphatidic acid or stearylamine and containing 6-carboxyfluorescein were injected into mice, incubated with mouse whole blood, plasma or serum or stored at 4°C. Liposomal stability, i.e. the extent to which 6-carboxyfluorescein is retained by liposomes, was dependent on their cholesterol content. (1) Cholesterol-rich (egg phosphatidylcholine/cholesterol, 7:7 molar ratio) liposomes, regardless of surface charge, remained stable in the blood of intravenously injected animals for up to at least 400min. In addition, stability of cholesterol-rich liposomes was largely maintained in vitro in the presence of whole blood, plasma or serum for at least 90min. (2) Cholesterol-poor (egg phosphatidylcholine/cholesterol, 7:2 molar ratio) or cholesterol-free (egg phosphatidylcholine) liposomes lost very rapidly (at most within 2min) much of their stability after intravenous injection or upon contact with whole blood, plasma or serum. Whole blood and to some extent plasma were less detrimental to stability than was serum. (3) After intraperitoneal injection, neutral cholesterol-rich liposomes survived in the peritoneal cavity to enter the blood circulation in their intact form. Liposomes injected intramuscularly also entered the circulation, although with somewhat diminished stability. (4) Stability of neutral and negatively charged cholesterol-rich liposomes stored at 4°C was maintained for several days, and by 53 days it had declined only moderately. Stored liposomes retained their unilamellar structure and their ability to remain stable in the blood after intravenous injection. (5) Control of liposomal stability by adjusting their cholesterol content may help in the design of liposomes for effective use in biological systems in vivo and in vitro.

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Synergistic In Vitro Antiretroviral Activity of a Humanized Monoclonal Anti-CD4 Antibody (TNX-355) and Enfuvirtide (T-20)

Antimicrobial Agents and Chemotherapy ◽

10.1128/aac.00761-05 ◽

2006 ◽

Vol 50 (6) ◽

pp. 2231-2233 ◽

Cited By ~ 39

Author(s):

Xing-Quan Zhang ◽

Meredith Sorensen ◽

Michael Fung ◽

Robert T. Schooley

Keyword(s):

Viral Replication ◽

Viral Entry ◽

Antiretroviral Agents ◽

Entry Inhibitors ◽

High Level ◽

Antiretroviral Activity

ABSTRACT Recently, antiretroviral agents directed at several steps involved in viral entry have been shown to reduce viral replication in vitro and in vivo. We have demonstrated a high level of in vitro synergistic antiretroviral activity for two entry inhibitors that are directed at sequential steps in the entry process.

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MERS-CoV Accessory ORFs Play Key Role for Infection and Pathogenesis

mBio ◽

10.1128/mbio.00665-17 ◽

2017 ◽

Vol 8 (4) ◽

Cited By ~ 55

Author(s):

Vineet D. Menachery ◽

Hugh D. Mitchell ◽

Adam S. Cockrell ◽

Lisa E. Gralinski ◽

Boyd L. Yount ◽

...

Keyword(s):

Public Health ◽

Viral Replication ◽

Rapid Response ◽

Mutant Virus ◽

Global Public Health ◽

Vaccine Platform ◽

Zoonotic Pathogens ◽

Related Group

ABSTRACT While dispensable for viral replication, coronavirus (CoV) accessory open reading frame (ORF) proteins often play critical roles during infection and pathogenesis. Utilizing a previously generated mutant, we demonstrate that the absence of all four Middle East respiratory syndrome CoV (MERS-CoV) accessory ORFs (deletion of ORF3, -4a, -4b, and -5 [dORF3-5]) has major implications for viral replication and pathogenesis. Importantly, attenuation of the dORF3-5 mutant is primarily driven by dysregulated host responses, including disrupted cell processes, augmented interferon (IFN) pathway activation, and robust inflammation. In vitro replication attenuation also extends to in vivo models, allowing use of dORF3-5 as a live attenuated vaccine platform. Finally, examination of ORF5 implicates a partial role in modulation of NF-κB-mediated inflammation. Together, the results demonstrate the importance of MERS-CoV accessory ORFs for pathogenesis and highlight them as potential targets for surveillance and therapeutic treatments moving forward. IMPORTANCE The initial emergence and periodic outbreaks of MERS-CoV highlight a continuing threat posed by zoonotic pathogens to global public health. In these studies, mutant virus generation demonstrates the necessity of accessory ORFs in regard to MERS-CoV infection and pathogenesis. With this in mind, accessory ORF functions can be targeted for both therapeutic and vaccine treatments in response to MERS-CoV and related group 2C coronaviruses. In addition, disruption of accessory ORFs in parallel may offer a rapid response platform to attenuation of future emergent strains based on both SARS- and MERS-CoV accessory ORF mutants. IMPORTANCE The initial emergence and periodic outbreaks of MERS-CoV highlight a continuing threat posed by zoonotic pathogens to global public health. In these studies, mutant virus generation demonstrates the necessity of accessory ORFs in regard to MERS-CoV infection and pathogenesis. With this in mind, accessory ORF functions can be targeted for both therapeutic and vaccine treatments in response to MERS-CoV and related group 2C coronaviruses. In addition, disruption of accessory ORFs in parallel may offer a rapid response platform to attenuation of future emergent strains based on both SARS- and MERS-CoV accessory ORF mutants.

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