scholarly journals An all-out assault on SARS-CoV-2 replication

2021 ◽  
Vol 478 (13) ◽  
pp. 2399-2403
Author(s):  
Ronald T. Hay
Keyword(s):  
Public Health ◽  
Viral Replication ◽  
Deleterious Effect ◽  
Unmet Need ◽  
Biochemical Assays ◽  
Biochemical Journal ◽  
Starting Point ◽  
Huge Impact ◽  
Serious Disease

The coronavirus pandemic has had a huge impact on public health with over 165 million people infected, 3.4 million deaths and a hugely deleterious effect on most economies. While vaccination effectively protects against the disease it is likely that viruses will evolve that can replicate in hosts immunised with the present vaccines. Thus, there is a great unmet need for effective antivirals that can block the development of serious disease in infected patients. The seven papers published in this issue of the Biochemical Journal address this need by expressing and purifying components required for viral replication, developing biochemical assays for these components and using the assays to screen a library of pre-existing pharmaceuticals for drugs that inhibited the target in vitro and inhibited viral replication in cell culture. The candidate drugs obtained are potential antivirals that may protect against SARS-CoV-2 infection. While not all the antiviral candidates will make it through to the clinic, they will be useful tool compounds and can act as the starting point for further drug discovery programmes.

scholarly journals Akt Interacts with Usutu Virus Polymerase, and Its Activity Modulates Viral Replication

Pathogens ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 244
Author(s):  
Laura Albentosa-González ◽  
Rosario Sabariegos ◽  
Armando Arias ◽  
Pilar Clemente-Casares ◽  
Antonio Mas
Keyword(s):  
Public Health ◽  
Confocal Microscopy ◽  
Viral Replication ◽  
Insufficient Data ◽  
Health Concerns ◽  
Usutu Virus ◽  
A Cell ◽  
Infected Cells ◽  
Specific Inhibitors

Usutu virus (USUV) is a flavivirus that mainly infects wild birds through the bite of Culex mosquitoes. Recent outbreaks have been associated with an increased number of cases in humans. Despite being a growing source of public health concerns, there is yet insufficient data on the virus or host cell targets for infection control. In this work we have investigated whether the cellular kinase Akt and USUV polymerase NS5 interact and co-localize in a cell. To this aim, we performed co-immunoprecipitation (Co-IP) assays, followed by confocal microscopy analyses. We further tested whether NS5 is a phosphorylation substrate of Akt in vitro. Finally, to examine its role in viral replication, we chemically silenced Akt with three inhibitors (MK-2206, honokiol and ipatasertib). We found that both proteins are localized (confocal) and pulled down (Co-IP) together when expressed in different cell lines, supporting the fact that they are interacting partners. This possibility was further sustained by data showing that NS5 is phosphorylated by Akt. Treatment of USUV-infected cells with Akt-specific inhibitors led to decreases in virus titers (>10-fold). Our results suggest an important role for Akt in virus replication and stimulate further investigations to examine the PI3K/Akt/mTOR pathway as an antiviral target.

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

mBio ◽  
2017 ◽  
Vol 8 (4) ◽  
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.

Inhibition by Phenol and Phenolic Acids of Platelet Release Reaction

1973 ◽  
Vol 30 (02) ◽  
pp. 334-338 ◽  
Author(s):  
Felisa C. Molinas
Keyword(s):  
Renal Failure ◽  
Phenolic Compounds ◽  
Phenolic Acids ◽  
Platelet Function ◽  
Deleterious Effect ◽  
Release Reaction ◽  
Contributory Factors ◽  
Adp Release ◽  
Platelet Release

SummaryIt has been postulated that the high phenol and phenolic acids plasmatic levels found in patients with chronic renal failure are contributory factors in the abnormal platelet function described in these patients. This hypothesis was corroborated by “in vitro” studies showing the deleterious effect of these compounds on certain platelet function after pre-incubation of PRP with phenol and phenolic compounds. The present studies were conducted to determine the influence of phenolic compounds on platelet release reaction. It was found that phenol inhibited from 62.5 to 100% the effect of the aggregating agents thrombin, adrenaline and ADP on platelet 5-HT-14C release. The phenolic acids p-, m-, and o-HPAA inhibited from 36.35 to 94.8% adrenaline and ADP-induced platelet 5-HT-14C release. Adrenaline-induced platelet ADP release was inhibited from 27.45 to 38.10% by the phenolic compounds. These findings confirm the hypothesis that phenolic compounds interfere with platelet function through the inhibition of the release reaction.

IMPACT OF SORBITOL- INDUCED OSMOTIC STRESS ON SOME BIOCHEMICAL TRAITS OF POTATO IN VITRO

2020 ◽  
Vol 51 (4) ◽  
pp. 1038-1047
Author(s):  
Mawia & et al.
Keyword(s):  
Ascorbic Acid ◽  
Osmotic Stress ◽  
Cytoplasmic Membrane ◽  
Genotypic Variation ◽  
Membrane Damage ◽  
Membrane Integrity ◽  
Culture Collection ◽  
Nutritive Medium ◽  
Starting Point

This study had as principal objective identification of osmotic-tolerant potato genotypes by using "in vitro" tissue culture and sorbitol as a stimulating agent, to induce water stress, which was added to the  culture nutritive medium in different concentration (0,50, 110, 220, 330 and 440 mM).  The starting point was represented by plantlets culture collection, belonging to eleven potato genotypes: Barcelona, Nectar, Alison, Jelly, Malice, Nazca, Toronto, Farida, Fabulla, Colomba and Spunta. Plantlets were multiplied between two internodes to obtain microcuttings (in sterile condition), which were inoculated on medium. Sorbitol-induced osmotic stress caused a significant reduction in the ascorbic acid, while the concentration of proline, H2O2 and solutes leakage increased compared with the control. Increased the proline content prevented lipid peroxidation, which played a pivotal role in the maintenance of membrane integrity under osmotic stress conditions. The extent of the cytoplasmic membrane damage depends on osmotic stress severity and the genotypic variation in the maintenance of membranes stability was highly associated with the ability of producing more amounts of osmoprotectants (proline) and the non-enzymic antioxidant ascorbic acid in response to osmotic stress level. The results showed that the genotypes Jelly, Nectar, Allison, Toronto, and Colomba are classified as highly osmotic stress tolerant genotypes, while the genotypes Nazca and Farida are classified as osmotic stress susceptible ones.

Enzyme Promiscuous Activity: How to Define it and its Evolutionary Aspects

2020 ◽  
Vol 27 (5) ◽  
pp. 400-410
Author(s):  
Valentina De Luca ◽  
Luigi Mandrich
Keyword(s):  
Gene Evolution ◽  
Sequence Divergence ◽  
High Specificity ◽  
Industrial Applications ◽  
Point Of View ◽  
Enzyme Promiscuity ◽  
Primary Activity ◽  
Starting Point ◽  
Main Activity

: Enzymes are among the most studied biological molecules because better understanding enzymes structure and activity will shed more light on their biological processes and regulation; from a biotechnological point of view there are many examples of enzymes used with the aim to obtain new products and/or to make industrial processes less invasive towards the environment. Enzymes are known for their high specificity in the recognition of a substrate but considering the particular features of an increasing number of enzymes this is not completely true, in fact, many enzymes are active on different substrates: this ability is called enzyme promiscuity. Usually, promiscuous activities have significantly lower kinetic parameters than to that of primary activity, but they have a crucial role in gene evolution. It is accepted that gene duplication followed by sequence divergence is considered a key evolutionary mechanism to generate new enzyme functions. In this way, promiscuous activities are the starting point to increase a secondary activity in the main activity and then get a new enzyme. The primary activity can be lost or reduced to a promiscuous activity. In this review we describe the differences between substrate and enzyme promiscuity, and its rule in gene evolution. From a practical point of view the knowledge of promiscuity can facilitate the in vitro progress of proteins engineering, both for biomedical and industrial applications. In particular, we report cases regarding esterases, phosphotriesterases and cytochrome P450.

Current Challenges in the Development of Vaccines and Drugs Against Emerging Vector-borne Diseases

2019 ◽  
Vol 26 (16) ◽  
pp. 2974-2986 ◽  
Author(s):  
Kwang-sun Kim
Keyword(s):  
New Host ◽  
In Vivo Models ◽  
Vector Borne Diseases ◽  
Novel Drugs ◽  
Huge Impact ◽  
Tick Borne Disease ◽  
Vector Borne ◽  
Living Organisms

Vectors are living organisms that transmit infectious diseases from an infected animal to humans or another animal. Biological vectors such as mosquitoes, ticks, and sand flies carry pathogens that multiply within their bodies prior to delivery to a new host. The increased prevalence of Vector-Borne Diseases (VBDs) such as Aedes-borne dengue, Chikungunya (CHIKV), Zika (ZIKV), malaria, Tick-Borne Disease (TBD), and scrub typhus has a huge impact on the health of both humans and livestock worldwide. In particular, zoonotic diseases transmitted by mosquitoes and ticks place a considerable burden on public health. Vaccines, drugs, and vector control methods have been developed to prevent and treat VBDs and have prevented millions of deaths. However, development of such strategies is falling behind the rapid emergence of VBDs. Therefore, a comprehensive approach to fighting VBDs must be considered immediately. In this review, I focus on the challenges posed by emerging outbreaks of VBDs and discuss available drugs and vaccines designed to overcome this burden. Research into promising drugs needs to be upgraded and fast-tracked, and novel drugs or vaccines being tested in in vitro and in vivo models need to be moved into human clinical trials. Active preventive tactics, as well as new and upgraded diagnostics, surveillance, treatments, and vaccination strategies, need to be monitored constantly if we are to manage VBDs of medical importance.

Biological and In silico Studies on Synthetic Analogues of Tyrosine Betaine as Inhibitors of Neprilysin - A Drug Target for the Treatment of Heart Failure

2018 ◽  
Vol 24 (17) ◽  
pp. 1899-1904
Author(s):  
Daniel Fabio Kawano ◽  
Marcelo Rodrigues de Carvalho ◽  
Mauricio Ferreira Marcondes Machado ◽  
Adriana Karaoglanovic Carmona ◽  
Gilberto Ubida Leite Braga ◽  
...  
Keyword(s):  
Heart Failure ◽  
Secondary Metabolites ◽  
Structural Similarity ◽  
Structural Features ◽  
Major Constituent ◽  
Binding Modes ◽  
Starting Point ◽  
In Silico Studies ◽  
Nep Inhibition

Background: Fungal secondary metabolites are important sources for the discovery of new pharmaceuticals, as exemplified by penicillin, lovastatin and cyclosporine. Searching for secondary metabolites of the fungi Metarhizium spp., we previously identified tyrosine betaine as a major constituent. Methods: Because of the structural similarity with other inhibitors of neprilysin (NEP), an enzyme explored for the treatment of heart failure, we devised the synthesis of tyrosine betaine and three analogues to be subjected to in vitro NEP inhibition assays and to molecular modeling studies. Results: In spite of the similar binding modes with other NEP inhibitors, these compounds only displayed moderate inhibitory activities (IC50 ranging from 170.0 to 52.9 µM). However, they enclose structural features required to hinder passive blood brain barrier permeation (BBB). Conclusions: Tyrosine betaine remains as a starting point for the development of NEP inhibitors because of the low probability of BBB permeation and, consequently, of NEP inhibition at the Central Nervous System, which is associated to an increment in the Aβ levels and, accordingly, with a higher risk for the onset of Alzheimer's disease.

Hybrid Design of Isonicotinic Acid Hydrazide Derivatives: Machine Learning Studies, Synthesis and Biological Evaluation of their Antituberculosis Activity

2020 ◽  
Vol 17 (3) ◽  
pp. 365-375
Author(s):  
Vasyl Kovalishyn ◽  
Diana Hodyna ◽  
Vitaliy O. Sinenko ◽  
Volodymyr Blagodatny ◽  
Ivan Semenyuta ◽  
...  
Keyword(s):  
Machine Learning ◽  
Isonicotinic Acid ◽  
Acid Hydrazide ◽  
Predictive Ability ◽  
Antitubercular Activity ◽  
Biological Evaluation ◽  
Starting Point ◽  
Binary Classifiers ◽  
Synthesis And Biological Evaluation

Background: Tuberculosis (TB) is an infection disease caused by Mycobacterium tuberculosis (Mtb) bacteria. One of the main causes of mortality from TB is the problem of Mtb resistance to known drugs. Objective: The goal of this work is to identify potent small molecule anti-TB agents by machine learning, synthesis and biological evaluation. Methods: The On-line Chemical Database and Modeling Environment (OCHEM) was used to build predictive machine learning models. Seven compounds were synthesized and tested in vitro for their antitubercular activity against H37Rv and resistant Mtb strains. Results: A set of predictive models was built with OCHEM based on a set of previously synthesized isoniazid (INH) derivatives containing a thiazole core and tested against Mtb. The predictive ability of the models was tested by a 5-fold cross-validation, and resulted in balanced accuracies (BA) of 61–78% for the binary classifiers. Test set validation showed that the models could be instrumental in predicting anti- TB activity with a reasonable accuracy (with BA = 67–79 %) within the applicability domain. Seven designed compounds were synthesized and demonstrated activity against both the H37Rv and multidrugresistant (MDR) Mtb strains resistant to rifampicin and isoniazid. According to the acute toxicity evaluation in Daphnia magna neonates, six compounds were classified as moderately toxic (LD50 in the range of 10−100 mg/L) and one as practically harmless (LD50 in the range of 100−1000 mg/L). Conclusion: The newly identified compounds may represent a starting point for further development of therapies against Mtb. The developed models are available online at OCHEM http://ochem.eu/article/11 1066 and can be used to virtually screen for potential compounds with anti-TB activity.

ACIS, A Novel KepTide™, Binds to ACE-2 Receptor and Inhibits the Infection of SARS-CoV2 Virus in vitro in Primate Kidney Cells: Therapeutic Implications for COVID-19 (Preprint)

2020 ◽  
Author(s):  
Avik Sotira Scientific
Keyword(s):  
Social Life ◽  
Plaque Assay ◽  
Host Cells ◽  
Surface Glycoprotein ◽  
Crystallographic Structure ◽  
Therapeutic Implications ◽  
Biochemical Assays ◽  
Targeted Medicine

UNSTRUCTURED Coronavirus disease 2019 (COVID-19) is a severe acute respiratory syndrome (SARS) caused by a virus known as SARS-Coronavirus 2 (SARS-CoV2). Without a targeted-medicine, this disease has been causing a massive humanitarian crisis not only in terms of mortality, but also imposing a lasting damage to social life and economic progress of humankind. Therefore, an immediate therapeutic strategy needs to be intervened to mitigate this global crisis. Here, we report a novel KepTide™ (Knock-End Peptide) therapy that nullifies SARS-CoV2 infection. SARS-CoV2 employs its surface glycoprotein “spike” (S-glycoprotein) to interact with angiotensin converting enzyme-2 (ACE-2) receptor for its infection in host cells. Based on our in-silico-based homology modeling study validated with a recent X-ray crystallographic structure (PDB ID:6M0J), we have identified that a conserved motif of S-glycoprotein that intimately engages multiple hydrogen-bond (H-bond) interactions with ACE-2 enzyme. Accordingly, we designed a peptide, termed as ACIS (ACE-2 Inhibitory motif of Spike), that displayed significant affinity towards ACE-2 enzyme as confirmed by biochemical assays such as BLItz and fluorescence polarization assays. Interestingly, more than one biochemical modifications were adopted in ACIS in order to enhance the inhibitory action of ACIS and hence called as KEpTide™. Consequently, a monolayer invasion assay, plaque assay and dual immunofluorescence analysis further revealed that KEpTide™ efficiently mitigated the infection of SARS-CoV2 in vitro in VERO E6 cells. Finally, evaluating the relative abundance of ACIS in lungs and the potential side-effects in vivo in mice, our current study discovers a novel KepTide™ therapy that is safe, stable, and robust to attenuate the infection of SARS-CoV2 virus if administered intranasally. INTERNATIONAL REGISTERED REPORT RR2-https://doi.org/10.1101/2020.10.13.337584

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