scholarly journals Toward a Taxonomy of Virus-ncRNAs Interactions in an RNA World for Disentangling Some Tiny Secrets of Dengue Virus

2021 ◽  
Author(s):  
Clara Isabel Bermudez-Santana ◽  
Juan Carlos Gallego-Gómez
Keyword(s):  
Viral Infections ◽  
Rna World ◽  
Rna Virus ◽  
Denv Infection ◽  
Cell Physiology ◽  
Cellular Functions ◽  
Viral Packaging ◽  
Viral Genomes ◽  
Cellular Factors ◽  
Regulation Functions

In recent years, the role of non-coding RNAs (ncRNAs) in regulating cell physiology has begun to be better understood. Recent discoveries in viral molecular biology have revealed that such cellular functions are disturbed during viral infections mainly due to host cell ncRNAs, cellular factors, and virus-derived ncRNAs. Apart from the interplay between those molecules, other interactions derive from the specific folding of RNA virus genomes. These fulfill canonical regulation functions such as replication, translation, and viral packaging. In some cases, folds serve as precursors of small viral RNAs whose biogenesis is not yet clearly understood. Since ncRNAs and RNA viral genomes modulate complex molecular and cellular processes in viral infections, a new taxonomy is being proposed here overarching three main categories, considering the current information about ncRNA interactions in some well-known viral infections. The first category shows examples of host ncRNAs associated with the trigger of the immune response under viral infections. The second category describes interactions between the virus and host ncRNAs. The last category shows how the shape of the RNA viral genome is essential in processing RNAs derived from viruses. Finally, we introduce evidence of how these three categories can also work as a framework in order to organize known interactions of ncRNAs and cellular factors under DENV infection. This new taxonomy of interactions provides a comprehensive framework for organizing the ncRNA regulatory roles in the context of viral interactions and an RNA world.

The Role of microRNAs in the Viral Infections

2019 ◽  
Vol 24 (39) ◽  
pp. 4659-4667 ◽  
Author(s):  
Mona Fani ◽  
Milad Zandi ◽  
Majid Rezayi ◽  
Nastaran Khodadad ◽  
Hadis Langari ◽  
...  
Keyword(s):  
Viral Infections ◽  
Rna Viruses ◽  
Regulation Of Gene Expression ◽  
Molecular Structures ◽  
Main Function ◽  
Cellular Functions ◽  
Viral Genes ◽  
Non Coding Rnas ◽  
Post Transcriptional Regulation

MicroRNAs (miRNAs) are non-coding RNAs with 19 to 24 nucleotides which are evolutionally conserved. MicroRNAs play a regulatory role in many cellular functions such as immune mechanisms, apoptosis, and tumorigenesis. The main function of miRNAs is the post-transcriptional regulation of gene expression via mRNA degradation or inhibition of translation. In fact, many of them act as an oncogene or tumor suppressor. These molecular structures participate in many physiological and pathological processes of the cell. The virus can also produce them for developing its pathogenic processes. It was initially thought that viruses without nuclear replication cycle such as Poxviridae and RNA viruses can not code miRNA, but recently, it has been proven that RNA viruses can also produce miRNA. The aim of this articles is to describe viral miRNAs biogenesis and their effects on cellular and viral genes.

scholarly journals The Pleiotropic Function of Human Sirtuins as Modulators of Metabolic Pathways and Viral Infections

Cells ◽  
2021 ◽  
Vol 10 (2) ◽  
pp. 460
Author(s):  
Mohammed Hamed Alqarni ◽  
Ahmed Ibrahim Foudah ◽  
Magdy Mohamed Muharram ◽  
Nikolaos E. Labrou
Keyword(s):  
Metabolic Pathways ◽  
Histone Deacetylases ◽  
Viral Infections ◽  
Cell Physiology ◽  
Functional Roles ◽  
Regulatory Processes ◽  
Complex Functions ◽  
Natural Polyphenol ◽  
Antiviral Targets

Sirtuins (SIRTs) are nicotinamide adenine dinucleotide-dependent histone deacetylases that incorporate complex functions in the mechanisms of cell physiology. Mammals have seven distinct members of the SIRT family (SIRT1-7), which play an important role in a well-maintained network of metabolic pathways that control and adapt the cell to the environment, energy availability and cellular stress. Until recently, very few studies investigated the role of SIRTs in modulating viral infection and progeny. Recent studies have demonstrated that SIRT1 and SIRT2 are promising antiviral targets because of their specific connection to numerous metabolic and regulatory processes affected during infection. In the present review, we summarize some of the recent progress in SIRTs biochemistry and their emerging function as antiviral targets. We also discuss the potential of natural polyphenol-based SIRT modulators to control their functional roles in several diseases including viral infections.

scholarly journals Fludarabine Inhibits Infection of Zika Virus, SFTS Phlebovirus, and Enterovirus A71

Viruses ◽  
2021 ◽  
Vol 13 (5) ◽  
pp. 774
Author(s):  
Chengfeng Gao ◽  
Chunxia Wen ◽  
Zhifeng Li ◽  
Shuhan Lin ◽  
Shu Gao ◽  
...  
Keyword(s):  
Broad Spectrum ◽  
Zika Virus ◽  
Therapeutic Agent ◽  
Viral Infections ◽  
Rna Virus ◽  
Emerging Viruses ◽  
Enterovirus A71 ◽  
Ic50 Values ◽  
High Doses ◽  
Severe Fever

Viral infections are one of the leading causes in human mortality and disease. Broad-spectrum antiviral drugs are a powerful weapon against new and re-emerging viruses. However, viral resistance to existing broad-spectrum antivirals remains a challenge, which demands development of new broad-spectrum therapeutics. In this report, we showed that fludarabine, a fluorinated purine analogue, effectively inhibited infection of RNA viruses, including Zika virus, Severe fever with thrombocytopenia syndrome virus, and Enterovirus A71, with all IC50 values below 1 μM in Vero, BHK21, U251 MG, and HMC3 cells. We observed that fludarabine has shown cytotoxicity to these cells only at high doses indicating it could be safe for future clinical use if approved. In conclusion, this study suggests that fludarabine could be developed as a potential broad-spectrum anti-RNA virus therapeutic agent.

scholarly journals Redox-Modulating Agents in the Treatment of Viral Infections

2020 ◽  
Vol 21 (11) ◽  
pp. 4084 ◽  
Author(s):  
Paola Checconi ◽  
Marta De Angelis ◽  
Maria Elena Marcocci ◽  
Alessandra Fraternale ◽  
Mauro Magnani ◽  
...  
Keyword(s):  
Inflammatory Response ◽  
Redox State ◽  
Viral Infections ◽  
Rna Virus ◽  
Influenza Virus Infection ◽  
Redox Balance ◽  
Physiological Conditions ◽  
Cell Functions ◽  
Enzymatic Systems ◽  
Strong Inflammatory Response

Viruses use cell machinery to replicate their genome and produce viral proteins. For this reason, several intracellular factors, including the redox state, might directly or indirectly affect the progression and outcome of viral infection. In physiological conditions, the redox balance between oxidant and antioxidant species is maintained by enzymatic and non-enzymatic systems, and it finely regulates several cell functions. Different viruses break this equilibrium and induce an oxidative stress that in turn facilitates specific steps of the virus lifecycle and activates an inflammatory response. In this context, many studies highlighted the importance of redox-sensitive pathways as novel cell-based targets for therapies aimed at blocking both viral replication and virus-induced inflammation. In the review, we discuss the most recent findings in this field. In particular, we describe the effects of natural or synthetic redox-modulating molecules in inhibiting DNA or RNA virus replication as well as inflammatory pathways. The importance of the antioxidant transcription factor Nrf2 is also discussed. Most of the data reported here are on influenza virus infection. We believe that this approach could be usefully applied to fight other acute respiratory viral infections characterized by a strong inflammatory response, like COVID-19.

scholarly journals Current and Emerging Themes in the Structural Analysis of Viral RNA Genomes: Applications for the Development of Novel Therapeutic Drugs

2015 ◽  
Vol 1 (1) ◽  
pp. 15 ◽  
Author(s):  
Cristina Romero-López ◽  
Alfredo Berzal-Herranz
Keyword(s):  
Rna Folding ◽  
Viral Infections ◽  
Genome Structure ◽  
Rna Molecules ◽  
Molecular Virology ◽  
Viral Genomes ◽  
Viral Propagation ◽  
Bioinformatic Tools ◽  
Rna Domains ◽  
Functional Rna

RNA molecules assume different roles in many different biological processes. This functional diversity is intimately related to RNA folding. In recent years, advances in the field of structure analysis by high-throughput methodologies and the development of novel potent bioinformatic tools have enabled the first structural maps of the eukaryotic transcriptome and the further establishment of novel function-structure relationships. This important progress has been of special relevance in the field of molecular virology. Viral genomes are compact entities that require overlapping coding levels to bear all the genetic information required for viral propagation. This is achieved by the acquisition of functional RNA domains, structurally conserved encoding units that perform essential roles for the consecution of the viral cycle. Interfering with the activity of these structural elements offers a potential means of treating viral infections, such as that caused by the hepatitis C virus, HCV. This review summarizes major achievements in the development of emerging methodologies for the analysis of RNA folding and their application to the study of the HCV genome structure. It will also examine the progress toward the design of novel antiviral compounds based in nucleic acids able to interfere with the folding of functional RNA domains.

scholarly journals Analysis of Porcine RIG-I Like Receptors Revealed the Positive Regulation of RIG-I and MDA5 by LGP2

2021 ◽  
Vol 12 ◽  
Author(s):  
Shuangjie Li ◽  
Jie Yang ◽  
Yuanyuan Zhu ◽  
Hui Wang ◽  
Xingyu Ji ◽  
...  
Keyword(s):  
Cell Activation ◽  
Viral Infections ◽  
Rna Virus ◽  
Gene Knockout ◽  
Constitutive Activity ◽  
Virus Infections ◽  
Positive Regulation ◽  
Dsrna Binding ◽  
Livestock Animal ◽  
Signaling Activity

The RLRs play critical roles in sensing and fighting viral infections especially RNA virus infections. Despite the extensive studies on RLRs in humans and mice, there is a lack of systemic investigation of livestock animal RLRs. In this study, we characterized the porcine RLR members RIG-I, MDA5 and LGP2. Compared with their human counterparts, porcine RIG-I and MDA5 exhibited similar signaling activity to distinct dsRNA and viruses, via similar and cooperative recognitions. Porcine LGP2, without signaling activity, was found to positively regulate porcine RIG-I and MDA5 in transfected porcine alveolar macrophages (PAMs), gene knockout PAMs and PK-15 cells. Mechanistically, LGP2 interacts with RIG-I and MDA5 upon cell activation, and promotes the binding of dsRNA ligand by MDA5 as well as RIG-I. Accordingly, porcine LGP2 exerted broad antiviral functions. Intriguingly, we found that porcine LGP2 mutants with defects in ATPase and/or dsRNA binding present constitutive activity which are likely through RIG-I and MDA5. Our work provided significant insights into porcine innate immunity, species specificity and immune biology.

Mechanisms of Action of Ribavirin in Antiviral Therapies

2001 ◽  
Vol 12 (5) ◽  
pp. 261-272 ◽  
Author(s):  
Robert C Tam ◽  
Johnson YN Lau ◽  
Zhi Hong
Keyword(s):  
Hepatitis C ◽  
Viral Infections ◽  
Rna Virus ◽  
Lassa Fever ◽  
Biological Properties ◽  
Interferon Α ◽  
Hepatitis C Infection ◽  
Antiviral Activities ◽  
Syncytial Virus

Although ribavirin was originally synthesized over 30 years ago and has been used to treat viral infections as monotherapy (respiratory syncytial virus and Lassa fever virus) or with interferon-α (IFN-α) as combination therapy (hepatitis C virus), the precise mechanism of its therapeutic activities remains controversial. In this review we focus on two main biological properties of ribavirin: its indirect and direct antiviral activities (with particular emphasis on its efficacy against chronic hepatitis C infection). Each property could individually or collectively account for its clinical efficacy against viral infections. First, with emphasis on the evidence for indirect activities of ribavirin, we will review the clinical observations that suggest that the immunomodulatory properties of ribavirin can in part account for its antiviral activities in vivo. We will then describe the mode of ribavirin's direct antiviral activities. These direct activities can be ascribed to several possible mechanisms, including the recently described activity as an RNA mutagen, a property that may be important in driving a rapidly mutating RNA virus over the threshold to ‘error catastrophe′.

Transcriptional response of Wolbachia-transinfected Aedes aegypti mosquito cells to dengue virus at early stages of infection

2022 ◽  
Vol 103 (1) ◽  
Author(s):  
Michael Leitner ◽  
Kayvan Etebari ◽  
Sassan Asgari
Keyword(s):  
Aedes Aegypti ◽  
Dengue Virus ◽  
Viral Infections ◽  
Transcriptional Response ◽  
Denv Infection ◽  
Content Type ◽  
Public Health Burden ◽  
Immune Genes ◽  
Link Type ◽  
Early Stages

Mosquito-borne flaviviruses are responsible for viral infections and represent a considerable public health burden. Aedes aegypti is the principal vector of dengue virus (DENV), therefore understanding the intrinsic virus–host interactions is vital, particularly in the presence of the endosymbiont Wolbachia, which blocks virus replication in mosquitoes. Here, we examined the transcriptional response of Wolbachia -transinfected Ae. aegypti Aag2 cells to DENV infection. We identified differentially expressed immune genes that play a key role in the activation of anti-viral defence such as the Toll and immune deficiency pathways. Further, genes encoding cytosine and N6-adenosine methyltransferases and SUMOylation, involved in post-transcriptional modifications, an antioxidant enzyme, and heat-shock response were up-regulated at the early stages of DENV infection and are reported here for the first time. Additionally, several long non-coding RNAs were among the differentially regulated genes. Our results provide insight into Wolbachia -transinfected Ae. aegypti’s initial virus recognition and transcriptional response to DENV infection.

scholarly journals DNA-induced 2′3′-cGAMP enhances haplotype-specific human STING cleavage by dengue protease

2020 ◽  
Vol 117 (27) ◽  
pp. 15947-15954 ◽  
Author(s):  
Chan-I Su ◽  
Yu-Ting Kao ◽  
Chao-Chen Chang ◽  
Yao Chang ◽  
Tzong-Shiann Ho ◽  
...  
Keyword(s):  
Innate Immunity ◽  
Rna Virus ◽  
Adaptor Protein ◽  
Denv Infection ◽  
Host Immunity ◽  
Virus Reactivation ◽  
Dna Virus ◽  
Exogenous Dna ◽  
Taiwanese People ◽  
Cyclic Dinucleotide

The cytosolic DNA sensor cGMP-AMP synthase (cGAS) synthesizes the noncanonical cyclic dinucleotide 2′3′-cGAMP to activate the adaptor protein stimulator of IFN genes (STING), thus awakening host immunity in response to DNA pathogen infection. However, dengue virus (DENV), an RNA virus without a DNA stage in its life cycle, also manipulates cGAS-STING–mediated innate immunity by proteolytic degradation of STING. Here, we found that the sensitivity of STING to DENV protease varied with different human STING haplotypes. Exogenous DNA further enhanced DENV protease’s ability to interact and cleave protease-sensitive STING. DNA-enhanced STING cleavage was reduced in cGAS-knockdown cells and triggered by the cGAS product 2′3′-cGAMP. The source of DNA may not be endogenous mitochondrial DNA but rather exogenous reactivated viral DNA. Cells producing 2′3′-cGAMP by overexpressing cGAS or with DNA virus reactivation enhanced STING cleavage in neighboring cells harboring DENV protease. DENV infection reduced host innate immunity in cells with the protease-sensitive STING haplotype, whose homozygote genotype frequency was found significantly reduced in Taiwanese people with dengue fever. Therefore, the human STING genetic background and DNA pathogen coinfection may be the missing links contributing to DENV pathogenesis.

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