Therapeutic Repurposing Approach: New Opportunity for Developing Drugs Against COVID-19

The coronavirus disease 2019 (COVID-19) pandemic initiated by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) has encouraged the repurposing of various drugs to treat the morbidity, mortality, and extent of the disease. Nowadays, the COVID-19 pandemic is a major health concern as it has already affected the whole world in all aspects. Drug repurposing is considered a new potential strategy as it is a cost-effective and less time-consuming process to establish a new indication for existing drugs. The present chapter has focused on the pathophysiology of COVID-19 and the reuse of the drugs based on pharmacological mechanisms. In the literature, various drugs like favipiravir, lopinavir, ritonavir, arbidol, chloroquine, hydroxychloroquine, interferons, etc. have been reported for repurposing purposes against COVID-19. Most of them are effective in in vitro and clinical studies. Drugs act mainly on viral entry, viral replication, angiotensin-converting enzyme-2 (ACE2), inflammatory mechanisms, etc. Based on viral pathogenesis and the mechanism of drugs using in silico, in vitro, and clinical studies, repurposing medicines might be considered an excellent opportunity to cure COVID-19. © The Editor(s) (if applicable) and The Author(s), under exclusive license to Springer Nature Singapore Pte Ltd. 2023.

Traditional herbal medicine in the treatment of patients infected with new coronavirus

The purposes of this review was in the direction of epidemiology, causative agents, symptoms, vaccine research probabilities and COVID-19 infection novel Corona viruses that was investigated in China. The COVID-19 has surrounded viruses along with a practical sensation one stranded RNA genome and a nucleocapsid of helical uniformity. The COVID-19 is an enormous family of viruses that are prevalent in a public and large number of species of animals including hens, camels, bats, cat, and cattle. Human corona viruses can cause gentle disorder identical to a common cough, cold, while others reason more acute disease MERS (Middle East Respiratory Syndrome) and SARS (Severe Acute Respiratory Syndrome). Thus spreading the COVID-19 should be closely investigated to recognize the growth of particularly virulent strains in society at an early stage and to simplify the evolution of enough preventive and therapeutic measurements.Copyright © 2021, Health Biotechnology and Biopharma. All rights reserved.

Hybridization Chain Reaction Lateral Flow Assays for Amplified Instrument-Free At-Home SARS-CoV-2 Testing.

The lateral flow assay format enables rapid, instrument-free, at-home testing for SARS-CoV-2. Due to the absence of signal amplification, this simplicity comes at a cost in sensitivity. Here, we enhance sensitivity by developing an amplified lateral flow assay that incorporates isothermal, enzyme-free signal amplification based on the mechanism of hybridization chain reaction (HCR). The simplicity of the user experience is maintained using a disposable 3-channel lateral flow device to automatically deliver reagents to the test region in three successive stages without user interaction. To perform a test, the user loads the sample, closes the device, and reads the result by eye after 60 min. Detecting gamma-irradiated SARS-CoV-2 virions in a mixture of saliva and extraction buffer, the current amplified HCR lateral flow assay achieves a limit of detection of 200 copies/µL using available antibodies to target the SARS-CoV-2 nucleocapsid protein. By comparison, five commercial unamplified lateral flow assays that use proprietary antibodies exhibit limits of detection of 500 copies/µL, 1000 copies/µL, 2000 copies/µL, 2000 copies/µL, and 20,000 copies/µL. By swapping out antibody probes to target different pathogens, amplified HCR lateral flow assays offer a platform for simple, rapid, and sensitive at-home testing for infectious diseases. As an alternative to viral protein detection, we further introduce an HCR lateral flow assay for viral RNA detection.

Dynamic Inferences of Coronavirus Epidemiology Spread in Iraq Region

Covid illness (COVID-19) happened in December 2019 first in Wuhan city of Hubei region of China. World Health Organization (WHO) proclaimed the spread or transmission of this infection as a pandemic. The infection named as severe intense respiratory disorder Covid 2 (SARS-CoV-2) by the International Committee on Taxonomy of Viruses on February 11, 2020. Disease due to this novel-coronavirus is infectious. Therefore, modeling such disease is required to understand methods of transmission, spread, epidemic. Several researchers have found that the transfer of the virus occurs through human contact via their pathogens, such as coughing, sneezing, and breathing. With all sorts of preventive measures (social distancing, wearing mask and lockdown), there is a need to develop a dynamic model of epidemiology for infectious disease. In this article, we have developed a new epidemiological dynamical model-design towards simulating spread and awareness towards this genomic-virus. This model studies the complexity analysis including time series and phase dynamics for the development of the virus in Iraq. Examination helps the comprehension of episode of this infection towards different pieces of the mainland and the world. Accuracy in addition to, validity for the assessment would prove to be superior if models fit less of the data on basis of the features: population-mobility with natural-history, epidemiological-characteristics, & transmission-contrivances for virus-gene. It is concluded that for Iraq the spread is following the log normal behavior with long tail. © 2022 American Institute of Physics Inc.. All rights reserved.

RNA structure-altering mutations underlying positive selection on Spike protein reveal novel putative signatures to trace crossing host-species barriers in Betacoronavirus.

Similar to other RNA viruses, the emergence of Betacoronavirus relies on cross-species viral transmission, which requires careful health surveillance monitoring of protein-coding information as well as genome-wide analysis. Although the evolutionary jump from natural reservoirs to humans may be mainly traced-back by studying the effect that hotspot mutations have on viral proteins, it is largely unexplored if other impacts might emerge on the structured RNA genome of Betacoronavirus. In this survey, the protein-coding and viral genome architecture were simultaneously studied to uncover novel insights into cross-species horizontal transmission events. We analysed 1,252,952 viral genomes of SARS-CoV, MERS-CoV, and SARS-CoV-2 distributed across the world in bats, intermediate animals, and humans to build a new landscape of changes in the RNA viral genome. Phylogenetic analyses suggest that bat viruses are the most closely related to the time of most recent common ancestor of Betacoronavirus, and missense mutations in viral proteins, mainly in the S protein S1 subunit: SARS-CoV (G > T; A577S); MERS-CoV (C > T; S746R and C > T; N762A); and SARS-CoV-2 (A > G; D614G) appear to have driven viral diversification. We also found that codon sites under positive selection on S protein overlap with non-compensatory mutations that disrupt secondary RNA structures in the RNA genome complement. These findings provide pivotal factors that might be underlying the eventual jumping the species barrier from bats to intermediate hosts. Lastly, we discovered that nearly half of the Betacoronavirus genomes carry highly conserved RNA structures, and more than 90% of these RNA structures show negative selection signals, suggesting essential functions in the biology of Betacoronavirus that have not been investigated to date. Further research is needed on negatively selected RNA structures to scan for emerging functions like the potential of coding virus-derived small RNAs and to develop new candidate antiviral therapeutic strategies.

Deep Neural Network for Virus Mutation Prediction: A Comprehensive Review

Artificial intelligence (AI) and Deep Learning Algorithms are potential methods for preventing the alarmingly widespread RNA viruses and ensuring pandemic safety, they have become an integrative part of the modern scientific methodology, offering automated procedures for the prediction of a phenomenon based on past observations, unraveling underlying patterns in data and providing insights about the problem. With the continuous growth in the number of RNA Virus COVID-19 patients, likely, doctors and healthcare personnel won’t be helpful in treating every case. Thus, data scientists can help in the battle against RNA Viruses Mutations by implementing more innovative solutions in order to accomplish controlling severe acute respiratory syndrome quickly RNA Viruses are viruses that are made up of strands of RNA. This work studies the induction of machine learning models and motivating their design and purpose whenever possible. In the second part of this work, we analyze and discuss the biological data in the eyes of deep learning models. The core of our contributions rests in the role of machine learning in viruses pandemics. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

CORSID Enables de novo Identification of Transcription Regulatory Sequences and Genes in Coronaviruses

Coronaviruses are comprised of a single-stranded RNA genome that is ready to be translated by the host ribosome. © 2022, The Author(s), under exclusive license to Springer Nature Switzerland AG.

Simplified Point-of-Care Full SARS-CoV-2 Genome Sequencing Using Nanopore Technology.

The scale of the ongoing SARS-CoV-2 pandemic warrants the urgent establishment of a global decentralized surveillance system to recognize local outbreaks and the emergence of novel variants of concern. Among available deep-sequencing technologies, nanopore-sequencing could be an important cornerstone, as it is mobile, scalable, and cost-effective. Therefore, streamlined nanopore-sequencing protocols need to be developed and optimized for SARS-CoV-2 variants identification. We adapted and simplified existing workflows using the 'midnight' 1200 bp amplicon split primer sets for PCR, which produce tiled overlapping amplicons covering almost the entire SARS-CoV-2 genome. Subsequently, we applied Oxford Nanopore Rapid Barcoding and the portable MinION Mk1C sequencer combined with the interARTIC bioinformatics pipeline. We tested a simplified and less time-consuming workflow using SARS-CoV-2-positive specimens from clinical routine and identified the CT value as a useful pre-analytical parameter, which may help to decrease sequencing failures rates. Complete pipeline duration was approx. 7 h for one specimen and approx. 11 h for 12 multiplexed barcoded specimens. The adapted protocol contains fewer processing steps and can be completely conducted within one working day. Diagnostic CT values deduced from qPCR standardization experiments can act as principal criteria for specimen selection. As a guideline, SARS-CoV-2 genome copy numbers lower than 4 × 106 were associated with a coverage threshold below 20-fold and incompletely assembled SARS-CoV-2 genomes. Thus, based on the described thermocycler/chemistry combination, we recommend CT values of ~26 or lower to achieve full and high-quality SARS-CoV-2 (+)RNA genome coverage.

1H, 13C, 15N and 31P chemical shift assignment for stem-loop 4 from the 5'-UTR of SARS-CoV-2.

The SARS-CoV-2 virus is the cause of the respiratory disease COVID-19. As of today, therapeutic interventions in severe COVID-19 cases are still not available as no effective therapeutics have been developed so far. Despite the ongoing development of a number of effective vaccines, therapeutics to fight the disease once it has been contracted will still be required. Promising targets for the development of antiviral agents against SARS-CoV-2 can be found in the viral RNA genome. The 5'- and 3'-genomic ends of the 30 kb SCoV-2 genome are highly conserved among Betacoronaviruses and contain structured RNA elements involved in the translation and replication of the viral genome. The 40 nucleotides (nt) long highly conserved stem-loop 4 (5_SL4) is located within the 5'-untranslated region (5'-UTR) important for viral replication. 5_SL4 features an extended stem structure disrupted by several pyrimidine mismatches and is capped by a pentaloop. Here, we report extensive 1H, 13C, 15N and 31P resonance assignments of 5_SL4 as the basis for in-depth structural and ligand screening studies by solution NMR spectroscopy.

Nonlinear dynamics for the spread of pathogenesis of COVID-19 pandemic.

Coronaviruses did not invite attention at a global level and responsiveness until the series of 2003-SARS contagion followed by year-2012 MERS plus, most recently, 2019-nCoV eruptions. SARS-CoV &MERS-CoV are painstaking, extremely pathogenic. Also, very evidently, both have been communicated from bats to palm-civets & dromedary camels and further transferred ultimately to humans. No country has been deprived of this viral genomic contamination wherever populaces reside and are interconnected. This study aimed to develop a mathematical model for calculating the transmissibility of this viral genome. The analysis aids the study of the outbreak of this Virus towards the other parts of the continent and the world. The parameters such as population mobility, natural history, epidemiological characteristics, and the transmission mechanism towards viral spread when considered into crowd dynamism result in improved estimation. This article studies the impact of time on the amount of susceptible, exposed, the infected person taking into account asymptomatic and symptomatic ones; recovered i.e., removed from this model and the virus particles existing in the open surfaces. The transition from stable phase to attractor phase happens after 13 days i.e.; it takes nearly a fortnight for the spread to randomize among people. Further, the pandemic transmission remains in the attractor phase for a very long time if no control measures are taken up. The attractor-source phase continues up to 385 days i.e., more than a year, and perhaps stabilizes on 386th day as per the Lyapunov exponent's analysis. The time series helps to know the period of the Virus's survival in the open sources i.e. markets, open spaces and various other carriers of the Virus if not quarantined or sanitized. The Virus cease to exist in around 60 days if it does not find any carrier or infect more places, people etc. The changes in LCEs of all variables as time progresses for around 400 days have been forecasted. It can be observed that phase trajectories indicate how the two variables interact with each other and affect the overall system's dynamics. It has been observed that for exposed and asymptomatically infected (y-z), as exposed ones (y) change from 0 to 100 the value of asymptomatically infected (z) increased upto around 58, at exposed ones (y)=100, asymptomatically infected (z) has two values as 58 and 10 i.e. follows bifurcation and as exposed ones (y) changes values upto 180, the value of asymptomatically infected (z) decreases to 25 so for exposed ones (y) from 100 to 180, asymptomatically infected (z) varies from 58 to 25 to 10 follows bifurcation. Also, phase structures of exposed-symptomatically infected (y-u), exposed-removed (y-v), exposed-virus in the reservoir (y-w), asymptomatically infected-removed (z-v), symptomatically infected-removed (u-v) specifically depict bifurcations in various forms at different points. In case of asymptomatically infected-virus in the reservoir (z-w), at asymptomatically infected (z)=10, the value of viruses in the reservoir (w)=50, then as asymptomatically infected (z) increases to upto around 60. At this point, removed ones (v) increase from 50 to 70 and asymptomatically infected (z) decrease to 20 i.e., crosses the same value twice, which shows its limiting is known as limit cycle behavior and both the values tend to decrease towards zero. It shows a closed-loop limit cycle. Today, there has been no scientific revolution in the development of vaccination, nor has any antiviral treatment been successful, resulting in lack of its medication. Based on the phases, time series, and complexity analysis of the model's various parameters, it is studied to understand the variation in this pandemic's scenario.

Systematizing the genomic order and relatedness in the open reading frames (ORFs) of the coronaviruses.

The coronaviruses (CoVs), including SARS-CoV-2, the agent of the ongoing deadly CoVID-19 pandemic (Coronavirus disease-2019), represent a highly complex and diverse class of RNA viruses with large genomes, complex gene repertoire, and intricate transcriptional and translational mechanisms. The 3'-terminal one-third of the genome encodes four structural proteins, namely spike, envelope, membrane, and nucleocapsid, interspersed with genes for accessory proteins that are largely nonstructural and called 'open reading frame' (ORF) proteins with alphanumerical designations, but not in a consistent or sequential order. Here, I report a comparative study of these ORF proteins, mainly encoded in two gene clusters, i.e. between the Spike and the Envelope genes, and between the Membrane and the Nucleocapsid genes. For brevity and focus, a greater emphasis was placed on the first cluster, collectively designated as the 'orf3 region' for ease of referral. Overall, an apparently diverse set of ORFs, such as ORF3a, ORF3b, ORF3c, ORF3d, ORF4 and ORF5, but not necessarily numbered in that order on all CoV genomes, were analyzed along with other ORFs. Unexpectedly, the gene order or naming of the ORFs were never fully conserved even within the members of one Genus. These studies also unraveled hitherto unrecognized orf genes in alternative translational frames, encoding potentially novel polypeptides as well as some that are highly similar to known ORFs. Finally, several options of an inclusive and systematic numbering are proposed not only for the orf3 region but also for the other orf genes in the viral genome in an effort to regularize the apparently confusing names and orders. Regardless of the ultimate acceptability of one system over the others, this treatise is hoped to initiate an informed discourse in this area.

European context of the diversity and phylogenetic position of SARS-CoV-2 sequences from Polish COVID-19 patients.

To provide a comprehensive analysis of the SARS-CoV-2 sequence diversity in Poland in the European context. All publicly available (n = 115; GISAID database) whole-genome SARS-Cov-2 sequences from Polish samples, including those obtained during coronavirus testing performed in our COVID-19 Lab, were examined. Multiple sequence alignment of Polish isolates, phylogenetic analysis (ML tree), and multidimensional scaling (based on the pairwise DNA distances) were complemented by the comparison of the coronavirus clades frequency and diversity in the subset of over 5000 European GISAID sequences. Approximately seventy-seven percent of isolates in the European dataset carried frequent and ubiquitously found haplotypes; the remaining haplotype diversity was population-specific and resulted from population-specific mutations, homoplasies, and recombinations. Coronavirus strains circulating in Poland represented the variability found in other European countries. The prevalence of clades circulating in Poland was shifted in favor of GR, both in terms of the diversity (number of distinct haplotypes) and the frequency (number of isolates) of the clade. Polish-specific haplotypes were rare and could be explained by changes affecting common European strains. The analysis of the whole viral genomes allowed detection of several tight clusters of isolates, presumably reflecting local outbreaks. New mutations, homoplasies, and, to a smaller extent, recombinations increase SARS-CoV-2 haplotype diversity, but the majority of these variants do not increase in frequency and remains rare and population-specific. The spectrum of SARS-CoV-2 haplotypes in the Polish dataset reflects many independent transfers from a variety of sources, followed by many local outbreaks. The prevalence of the sequences belonging to the GR clade among Polish isolates is consistent with the European trend of the GR clade frequency increase.

Comprehensive in vivo secondary structure of the SARS-CoV-2 genome reveals novel regulatory motifs and mechanisms.

Severe-acute-respiratory-syndrome-related coronavirus 2 (SARS-CoV-2) is the positive-sense RNA virus that causes coronavirus disease 2019 (COVID-19). The genome of SARS-CoV-2 is unique among viral RNAs in its vast potential to form RNA structures, yet as much as 97% of its 30 kilobases have not been structurally explored. Here, we apply a novel long amplicon strategy to determine the secondary structure of the SARS-CoV-2 RNA genome at single-nucleotide resolution in infected cells. Our in-depth structural analysis reveals networks of well-folded RNA structures throughout Orf1ab and reveals aspects of SARS-CoV-2 genome architecture that distinguish it from other RNA viruses. Evolutionary analysis shows that several features of the SARS-CoV-2 genomic structure are conserved across ß-coronaviruses, and we pinpoint regions of well-folded RNA structure that merit downstream functional analysis. The native, secondary structure of SARS-CoV-2 presented here is a roadmap that will facilitate focused studies on the viral life cycle, facilitate primer design, and guide the identification of RNA drug targets against COVID-19.

Two Examples of RNA Aptamers with Antiviral Activity. Are Aptamers the Wished Antiviral Drugs?

The current Covid-19 pandemic has pointed out some major deficiencies of the even most advanced societies to fight against viral RNA infections. Once more, it has been demonstrated that there is a lack of efficient drugs to control RNA viruses. Aptamers are efficient ligands of a great variety of molecules including proteins and nucleic acids. Their specificity and mechanism of action make them very promising molecules for interfering with the function encoded in viral RNA genomes. RNA viruses store essential information in conserved structural genomic RNA elements that promote important steps for the consecution of the infective cycle. This work describes two well documented examples of RNA aptamers with antiviral activity against highly conserved structural domains of the HIV-1 and HCV RNA genome, respectively, performed in our laboratory. They are two good examples that illustrate the potential of the aptamers to fill the therapeutic gaps in the fight against RNA viruses.

Oral Methioninase for Covid-19 Methionine-restriction Therapy.

The Covid-19 pandemic is a world-wide crisis without an effective therapy. While most approaches to therapy are using repurposed drugs that were developed for other diseases, it is thought that targeting the biology of the SARS-CoV-2 virus, which causes Covid-19, can result in an effective therapeutic treatment. The coronavirus RNA cap structure is methylated by two viral methyltransferases that transfer methyl groups from S-adenosylmethionine (SAM). The proper methylation of the virus depends on the level of methionine in the host to form SAM. Herein, we propose to restrict methionine availability by treating the patient with oral recombinant methioninase, aiming to treat Covid-19. By restricting methionine we not only interdict viral replication, which depends on the viral RNA cap methyaltion, but also inhibit the proliferation of the infected cells, which have an increased requirement for methionine. Most importantly, the virally-induced T-cell- and macrophage-mediated cytokine storm, which seems to be a significant cause for Covid-19 deaths, can also be inhibited by restricting methionine, since T-cell and macrophrage activation greatly increases the methionine requirement for these cells. The evidence reviewed here suggests that oral recombinant methioninase could be a promising treatment for coronavirus patients.