scholarly journals miRCOVID-19: Potential Targets of Human miRNAs in SARS-CoV-2 for RNA-Based Drug Discovery

2021 ◽  
Vol 7 (1) ◽  
pp. 18
Author(s):  
Tanvir Alam ◽  
Leonard Lipovich

Sense-antisense interactions of long and short RNAs in human cells are integral to post-transcriptional gene regulation, in particular that of mRNAs by microRNAs. Many viruses, including severe acute respiratory syndrome coronavirus 2 SARS-CoV-2 (the causative agent of coronavirus disease 2019, COVID-19), have RNA genomes, and interactions between host and viral RNAs, while known to be functional in other viral diseases, have not yet been investigated in COVID-19. To remedy this gap in knowledge, we present miRCOVID-19, a computational meta-analysis framework identifying the predicted binding sites of human microRNAs along the SARS-CoV-2 RNA genome. To highlight the potential relevance of SARS-CoV-2-genome-complementary miRNAs to COVID-19 pathogenesis, we assessed their expression in COVID-19-relevant tissues using public transcriptome data. miRCOVID-19 identified 14 high-confidence mature miRNAs that are highly likely to interact with the SARS-CoV-2 genome and are expressed in diverse respiratory epithelial and immune cell types that are relevant to COVID-19 pathogenesis. As a proof of principle, we have shown that human miR-122, a previously known co-factor of another RNA virus, the hepatitis C virus (HCV) whose genome it binds as a prerequisite for pathogenesis, was predicted to also bind the SARS-CoV-2 RNA genome with high affinity, suggesting the perspective of repurposing anti-HCV RNA-based drugs, such as Miravirsen, to treat COVID-19. Our study is the first to identify all high-confidence binding sites of human miRNAs in the SARS-CoV-2 genome using multiple tools. Our work directly facilitates experimental validation of the reported targets, which would accelerate RNA-based drug discovery for COVID-19 and has the potential to provide new avenues for treating symptomatic COVID-19, and block SARS-CoV-2 replication, in humans.

2019 ◽  
Author(s):  
Yiyang Zhou ◽  
Andrew Routh

AbstractTo characterize RNA-capsid binding sites genome-wide within mature RNA virus particles, we have developed a Next-Generation Sequencing (NGS) platform: Photo-Activatable Ribonucleoside Cross-Linking (PAR-CL). In PAR-CL, 4-thiouracil is incorporated into the encapsidated genomes of authentic virus particles and subsequently UV-crosslinked to adjacent capsid proteins. We demonstrate that PAR-CL can readily and reliably identify capsid binding sites in genomic viral RNA by detecting crosslink-specific uridine to cytidine transitions in NGS data. Using Flock House virus (FHV) as a model system, we identified highly consistent and significant PAR-CL signals across virus RNA genome indicating a clear tropism of the encapsidated RNA genome. Certain interaction sites correlate to previously identified FHV RNA motifs. We additionally performed dimethyl sulfate mutational profiling with sequencing (DMS-MaPseq) to generate a high-resolution profile of single-stranded genomic RNA inside viral particles. Combining PAR-CL and DMS-MaPseq reveals that the predominant RNA-capsid sites favor double-stranded RNA regions. We disrupted secondary structures associated with PAR-CL sites using synonymous mutations, resulting in varied effects to virus replication, propagation, and packaging. Certain mutations showed substantial deficiency in virus replication, suggesting these RNA-capsid sites are multifunctional. These provide further evidence to support that FHV packaging and replication are highly coordinated and inter-dependent events.ImportanceIcosahedral RNA viruses must package their genetic cargo into the restrictive and tight confines of the protected virions. High resolution structures of RNA viruses have been solved by Cryo-EM and crystallography, but the encapsidated RNA often eluded visualization due to the icosahedral averaging imposed during image reconstruction. Asymmetrical reconstructions of some icosahedral RNA virus particles have revealed that the encapsidated RNAs conform to specific structures, which may be related to programmed assembly pathway or an energy-minima for RNA folding during or after encapsidation. Despite these advances, determining whether encapsidated RNA genomes conform to a single structure and determining what regions of the viral RNA genome interact with the inner surface of the capsid shell remains challenging. Furthermore, it remains to be determined whether there exists a single RNA structure with conserved topology in RNA virus particles or an ensemble of genomic RNA structures. This is important as resolving these features will inform the elusive structures of the asymmetrically encapsidated genomic material and how virus particles are assembled.


2015 ◽  
Vol 112 (12) ◽  
pp. 3692-3697 ◽  
Author(s):  
David M. Mauger ◽  
Michael Golden ◽  
Daisuke Yamane ◽  
Sara Williford ◽  
Stanley M. Lemon ◽  
...  

Hepatitis C virus (HCV) infects over 170 million people worldwide and is a leading cause of liver disease and cancer. The virus has a 9,650-nt, single-stranded, messenger-sense RNA genome that is infectious as an independent entity. The RNA genome has evolved in response to complex selection pressures, including the need to maintain structures that facilitate replication and to avoid clearance by cell-intrinsic immune processes. Here we used high-throughput, single-nucleotide resolution information to generate and functionally test data-driven structural models for three diverse HCV RNA genomes. We identified, de novo, multiple regions of conserved RNA structure, including all previously characterized cis-acting regulatory elements and also multiple novel structures required for optimal viral fitness. Well-defined RNA structures in the central regions of HCV genomes appear to facilitate persistent infection by masking the genome from RNase L and double-stranded RNA-induced innate immune sensors. This work shows how structure-first comparative analysis of entire genomes of a pathogenic RNA virus enables comprehensive and concise identification of regulatory elements and emphasizes the extensive interrelationships among RNA genome structure, viral biology, and innate immune responses.


Molecules ◽  
2021 ◽  
Vol 26 (3) ◽  
pp. 651
Author(s):  
Koji Umezawa ◽  
Isao Kii

Drug discovery using small molecule inhibitors is reaching a stalemate due to low selectivity, adverse off-target effects and inevitable failures in clinical trials. Conventional chemical screening methods may miss potent small molecules because of their use of simple but outdated kits composed of recombinant enzyme proteins. Non-canonical inhibitors targeting a hidden pocket in a protein have received considerable research attention. Kii and colleagues identified an inhibitor targeting a transient pocket in the kinase DYRK1A during its folding process and termed it FINDY. FINDY exhibits a unique inhibitory profile; that is, FINDY does not inhibit the fully folded form of DYRK1A, indicating that the FINDY-binding pocket is hidden in the folded form. This intriguing pocket opens during the folding process and then closes upon completion of folding. In this review, we discuss previously established kinase inhibitors and their inhibitory mechanisms in comparison with FINDY. We also compare the inhibitory mechanisms with the growing concept of “cryptic inhibitor-binding sites.” These sites are buried on the inhibitor-unbound surface but become apparent when the inhibitor is bound. In addition, an alternative method based on cell-free protein synthesis of protein kinases may allow the discovery of small molecules that occupy these mysterious binding sites. Transitional folding intermediates would become alternative targets in drug discovery, enabling the efficient development of potent kinase inhibitors.


2020 ◽  
Vol 8 (Suppl 3) ◽  
pp. A520-A520
Author(s):  
Son Pham ◽  
Tri Le ◽  
Tan Phan ◽  
Minh Pham ◽  
Huy Nguyen ◽  
...  

BackgroundSingle-cell sequencing technology has opened an unprecedented ability to interrogate cancer. It reveals significant insights into the intratumoral heterogeneity, metastasis, therapeutic resistance, which facilitates target discovery and validation in cancer treatment. With rapid advancements in throughput and strategies, a particular immuno-oncology study can produce multi-omics profiles for several thousands of individual cells. This overflow of single-cell data poses formidable challenges, including standardizing data formats across studies, performing reanalysis for individual datasets and meta-analysis.MethodsN/AResultsWe present BioTuring Browser, an interactive platform for accessing and reanalyzing published single-cell omics data. The platform is currently hosting a curated database of more than 10 million cells from 247 projects, covering more than 120 immune cell types and subtypes, and 15 different cancer types. All data are processed and annotated with standardized labels of cell types, diseases, therapeutic responses, etc. to be instantly accessed and explored in a uniform visualization and analytics interface. Based on this massive curated database, BioTuring Browser supports searching similar expression profiles, querying a target across datasets and automatic cell type annotation. The platform supports single-cell RNA-seq, CITE-seq and TCR-seq data. BioTuring Browser is now available for download at www.bioturing.com.ConclusionsN/A


2021 ◽  
Vol 22 (7) ◽  
pp. 3406
Author(s):  
Robert L. Medcalf ◽  
Charithani B. Keragala

The fibrinolytic system provides an essential means to remove fibrin deposits and blood clots. The actual protease responsible for this is plasmin, formed from its precursor, plasminogen. Fibrin is heralded as it most renowned substrate but for many years plasmin has been known to cleave many other substrates, and to also activate other proteolytic systems. Recent clinical studies have shown that the promotion of plasmin can lead to an immunosuppressed phenotype, in part via its ability to modulate cytokine expression. Almost all immune cells harbor at least one of a dozen plasminogen receptors that allows plasmin formation on the cell surface that in turn modulates immune cell behavior. Similarly, a multitude of pathogens can also express their own plasminogen activators, or contain surface proteins that provide binding sites host plasminogen. Plasmin formed under these circumstances also empowers these pathogens to modulate host immune defense mechanisms. Phylogenetic studies have revealed that the plasminogen activating system predates the appearance of fibrin, indicating that plasmin did not evolve as a fibrinolytic protease but perhaps has its roots as an immune modifying protease. While its fibrin removing capacity became apparent in lower vertebrates these primitive under-appreciated immune modifying functions still remain and are now becoming more recognised.


2021 ◽  
Author(s):  
Edward Kennedy ◽  
Agnieszka Denslow ◽  
Jacqueline Hewett ◽  
Lingxin Kong ◽  
Ana De Almeida ◽  
...  

Abstract Oncolytic viruses (OVs) are an emerging therapeutic approach for the treatment of cancer. Clinical benefit has been demonstrated for intratumoral administration, but the therapeutic effectiveness of intravenous delivery has been limited by neutralizing antibody responses against the virus. To circumvent this limitation, we developed Synthetic RNA viruses, a novel approach for intravenous and repeated administration of OVs, consisting of a viral RNA genome (vRNA) formulated within lipid nanoparticles. For two Synthetic RNA virus drug candidates, Seneca Valley virus (SVV) and Coxsackievirus A21 (CVA21), we demonstrate vRNA delivery, viral replication, spread, and lysis of tumor cells leading to potent anti-tumor efficacy, even in the presence of OV neutralizing antibodies in the bloodstream. Synthetic-SVV replication in tumors promoted immune cell infiltration and enhanced anti-tumor activity in combination with anti-PD-1 checkpoint inhibitor. Altogether, the Synthetic RNA virus platform provides an innovative approach that enables repeat intravenous administration of viral immunotherapy.


2021 ◽  
Vol 39 (15_suppl) ◽  
pp. 3076-3076
Author(s):  
Shengli Ding ◽  
Zhaohui Wang ◽  
Marcos Negrete Obando ◽  
Grecia rivera Palomino ◽  
Tomer Rotstein ◽  
...  

3076 Background: Preclinical models that can recapitulate patients’ intra-tumoral heterogeneity and microenvironment are crucial for tumor biology research and drug discovery. In particular, the ability to retain immune and other stromal cells in the microenvironment is vital for the development of immuno-oncology assays. However, current patient-derived organoid (PDO) models are largely devoid of immune components. Methods: We first developed an automated microfluidic and membrane platform that can generate tens of thousands of micro-organospheres from resected or biopsied clinical tumor specimens within an hour. We next characterized growth rate and drug response of micro-organospheres. Finally, extensive single-cell RNA-seq profiling were performed on both micro-organospheres and original tumor samples from lung, ovarian, kidney, and breast cancer patients. Results: Micro-organospheres derived from clinical tumor samples preserved all original tumor and stromal cells, including fibroblasts and all immune cell types. Single-cell analysis revealed that unsupervised clustering of tumor and non-tumor cells were identical between original tumors and the derived micro-organospheres. Quantification showed similar cell composition and percentages for all cell types and also preserved functional intra-tumoral heterogeneity.. An automated, end-to-end, high-throughput drug screening pipeline demonstrated that matched peripheral blood mononuclear cells (PBMCs) from the same patient added to micro-organospheres can be used to assess the efficacy of immunotherapy moieties. Conclusions: Micro-organospheres are a rapid and scalable platform to preserve patient tumor microenvironment and heterogeneity. This platform will be useful for precision oncology, drug discovery, and immunotherapy development. Funding sources: NIH U01 CA217514, U01 CA214300, Duke Woo Center for Big Data and Precision Health


Author(s):  
Jason Grebely ◽  
Lucy Tran ◽  
Louisa Degenhardt ◽  
Alexander Dowell-Day ◽  
Thomas Santo ◽  
...  

Abstract Background People who inject drugs (PWID) experience barriers to accessing testing and treatment for hepatitis C virus (HCV) infection. Opioid agonist therapy (OAT) may provide an opportunity to improve access to HCV care. This systematic review assessed the association of OAT and HCV testing, treatment, and treatment outcomes among PWID. Methods Bibliographic databases and conference presentations were searched for studies assessing the association between OAT and HCV testing, treatment, and treatment outcomes [direct-acting antiviral (DAA) therapy only] among people who inject drugs (in the past year). Meta-analysis was used to pool estimates. Results Among 9,877 articles identified, 22 studies conducted in Australia, Europe, North America, and Thailand were eligible and included. Risk of bias was serious in 21 studies and moderate in one study. Current/recent OAT was associated with an increased odds of recent HCV antibody testing [4 studies; odds ratio (OR), 1.80; 95% CI:1.36, 2.39), HCV RNA testing among those who were HCV antibody positive (2 studies; OR, 1.83; 95% CI:1.27, 2.62), and DAA treatment uptake among those who were HCV RNA positive (7 studies; OR 1.53; 95% CI: 1.07, 2.20). There was insufficient evidence of an association between OAT and treatment completion (9 studies) or sustained virologic response following DAA therapy (9 studies). Conclusions Opioid agonist therapy can increase linkage to HCV care, including uptake of HCV testing and treatment among PWID. This supports the scale-up of OAT as part of strategies to enhance HCV treatment to further HCV elimination efforts.


2019 ◽  
Vol 20 (24) ◽  
pp. 6218 ◽  
Author(s):  
Joseph T. Ortega ◽  
Beata Jastrzebska

G protein-coupled receptors (GPCRs) play a predominant role in the drug discovery effort. These cell surface receptors are activated by a variety of specific ligands that bind to the orthosteric binding pocket located in the extracellular part of the receptor. In addition, the potential binding sites located on the surface of the receptor enable their allosteric modulation with critical consequences for their function and pharmacology. For decades, drug discovery focused on targeting the GPCR orthosteric binding sites. However, finding that GPCRs can be modulated allosterically opened a new venue for developing novel pharmacological modulators with higher specificity. Alternatively, focus on discovering of non-retinoid small molecules beneficial in retinopathies associated with mutations in rhodopsin is currently a fast-growing pharmacological field. In this review, we summarize the accumulated knowledge on retinoid ligands and non-retinoid modulators of the light-sensing GPCR, rhodopsin and their potential in combating the specific vision-related pathologies. Also, recent findings reporting the potential of biologically active compounds derived from natural products as potent rod opsin modulators with beneficial effects against degenerative diseases related to this receptor are highlighted here.


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