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108 Publications visible to you, out of a total of 108

Abstract (Expand)

In the proposed study three major issues have been addressed: Firstly, the diversity of grapevine accessions worldwide and particularly in Armenia, a small country located in the largely volcanic … Armenian Highlands, is incredibly rich in cultivated and especially wild grapes; secondly, the information hidden in their (whole) genomes, e.g., about the domestication history of grapevine over the last 11,000 years and phenotypic traits such as cultivar utilization and a putative resistance against powdery mildew, and, thirdly machine learning methods to extract and to visualize this information in an easy to percept way. We shortly describe the Self Origanizing Maps (SOM) portrayal method called “SOMmelier” (as the vine-genome “waiter”) and illustrate its power by applying it to whole genome data of hundreds of grapevine accessions. We also give a short outlook on possible future directions of machine learning in grapevine transcriptomics and ampelogaphy.

Authors: Kristina Magaryan, Maria Nikogհosyan, Anush Baloyan, Hripsime Gasoyan, Emma Hovhannisyan, Levon Galstyan, Tomas Konecny, Arsen Arakelyan, Hans Binder

Date Published: 6th Dec 2023

Publication Type: Journal

Abstract (Expand)

Naturally abundant antimicrobial lipids, such as fatty acids and monoglycerides, that disrupt membrane-enveloped viruses are promising mitigants to inhibit African swine fever virus (ASFV). Among … mitigant candidates in this class, glycerol monolaurate (GML) has demonstrated particularly high antiviral activity against laboratory-adapted ASFV strains. However, there is an outstanding need to further determine the effects of GML on wild-type ASFV strains, which can have different virulence levels and sensitivities to membrane-disrupting compounds as compared to laboratory-adapted strains. Herein, we investigated the antiviral effects of GML on a highly virulent strain of a wild-type ASFV isolate (Armenia/07) in an in vitro porcine macrophage model. GML treatment caused a concentration-dependent reduction in viral infectivity, and there was a sharp transition between inactive and active GML concentrations. Low GML concentrations had negligible effect on viral infectivity, whereas sufficiently high GML concentrations caused a >99% decrease in viral infectivity. The concentration onset of antiviral activity matched the critical micelle concentration (CMC) value of GML, reinforcing that GML micelles play a critical role in enabling anti-ASFV activity. These findings validate that GML can potently inhibit wild-type ASFV infection of porcine macrophages and support a biophysical explanation to guide antimicrobial lipid performance optimization for pathogen mitigation applications.

Authors: Joshua A Jackman, Erik Arabyan, Hovakim Zakaryan, Charles C Elrod

Date Published: 25th Sep 2023

Publication Type: Journal

Abstract (Expand)

Most high throughput genomic data analysis pipelines currently rely on over-representation or gene set enrichment analysis (ORA/GSEA) approaches for functional analysis. In contrast, topology-based … pathway analysis methods, which offer a more biologically informed perspective by incorporating interaction and topology information, have remained underutilized and inaccessible due to various limiting factors. These methods heavily rely on the quality of pathway topologies and often utilize predefined topologies from databases without assessing their correctness. To address these issues and make topology-aware pathway analysis more accessible and flexible, we introduce the PSF (Pathway Signal Flow) toolkit R package. Our toolkit integrates pathway curation and topology-based analysis, providing interactive and command-line tools that facilitate pathway importation, correction, and modification from diverse sources. This enables users to perform topology-based pathway signal flow analysis in both interactive and command-line modes. To showcase the toolkit’s usability, we curated 36 KEGG signaling pathways and conducted several use-case studies, comparing our method with ORA and the topology-based signaling pathway impact analysis (SPIA) method. The results demonstrate that the algorithm can effectively identify ORA enriched pathways while providing more detailed branch-level information. Moreover, in contrast to the SPIA method, it offers the advantage of being cut-off free and less susceptible to the variability caused by selection thresholds. By combining pathway curation and topology-based analysis, the PSF toolkit enhances the quality, flexibility, and accessibility of topology-aware pathway analysis. Researchers can now easily import pathways from various sources, correct and modify them as needed, and perform detailed topology-based pathway signal flow analysis. In summary, our PSF toolkit offers an integrated solution that addresses the limitations of current topology-based pathway analysis methods. By providing interactive and command-line tools for pathway curation and topology-based analysis, we empower researchers to conduct comprehensive pathway analyses across a wide range of applications.

Authors: Siras Hakobyan, Ani Stepanyan, Lilit Nersisyan, Hans Binder, Arsen Arakelyan

Date Published: 23rd Aug 2023

Publication Type: Journal

Abstract (Expand)

The study of pathological processes in cells carrying mutations should be carried out in comparison with a healthy control group. Familial Mediterranean fever (FMF), which is caused by a mutation in … the MEFV gene, is predominantly found in people of Armenian nationality with the prevalence of 14–100 per 10000. We have obtained induced pluripotent stem cells (iPSCs) from Armenian healthy patient, which will be included as a control group in the study of this disease. iPSCs rapidly proliferate in colonies of cells with a typical pluripotent-like morphology, have a normal karyotype (46,XX). iPSCs express pluripotency markers (OCT4, SOX2, TRA-1–60, NANOG) and are able to give derivatives of three germ layers.

Authors: Elena V. Grigor’eva, Anastasia A. Malakhova, Lilit Ghukasyan, Varduhi Hayrapetyan, Sofi Atshemyan, Valentina Vardanyan, Suren M. Zakian, Roksana Zakharyan, Arsen Arakelyan

Date Published: 17th Jun 2023

Publication Type: Journal

Abstract (Expand)

Anti-CD19 CAR-T cell immunotherapy is a hopeful treatment option for patients with B cell lymphomas, however it copes with partly severe adverse effects like neurotoxicity. Single-cell resolved molecular … data sets in combination with clinical parametrization allow for comprehensive characterization of cellular subpopulations, their transcriptomic states, and their relation to the adverse effects. We here present a re-analysis of single-cell RNA sequencing data of 24 patients comprising more than 130,000 cells with focus on cellular states and their association to immune cell related neurotoxicity. For this, we developed a single-cell data portraying workflow to disentangle the transcriptional state space with single-cell resolution and its analysis in terms of modularly-composed cellular programs. We demonstrated capabilities of single-cell data portraying to disentangle transcriptional states using intuitive visualization, functional mining, molecular cell stratification, and variability analyses. Our analysis revealed that the T cell composition of the patient's infusion product as well as the spectrum of their transcriptional states of cells derived from patients with low ICANS grade do not markedly differ from those of cells from high ICANS patients, while the relative abundancies, particularly that of cycling cells, of LAG3-mediated exhaustion and of CAR positive cells, vary. Our study provides molecular details of the transcriptomic landscape with possible impact to overcome neurotoxicity. Keywords: CAR-T cell immunotherapy; bioinformatics workflow; data portraying; single-cell transcriptomics; transcriptional states. Copyright © 2022 Loeffler-Wirth, Rade, Arakelyan, Kreuz, Loeffler, Koehl, Reiche and Binder.

Authors: Henry Loeffler-Wirth, Michael Rade, Arsen Arakelyan, Markus Kreuz, Markus Loeffler, Ulrike Koehl, Kristin Reiche, Hans Binder

Date Published: 28th Sep 2022

Publication Type: Journal

Abstract (Expand)

In this work, we analysed human isolates of nontyphoidal Salmonella enterica subsp. enterica (NTS), which were collected from salmonellosis cases in Armenia from 1996 to 2019. This disease became a … leading food-borne bacterial infection in the region, with the younger age groups especially affected. The isolates were characterised by serotyping, Enterobacterial Repetitive Intergenic Consensus (ERIC-PCR) typing, and whole genome sequencing (WGS). The main serotypes were S. Typhimurium, S. Enteritidis, and S. Arizonae. ERIC-PCR indicated a high degree of clonality among S. Typhimurium strains, which were also multidrug-resistant and produced extended spectrum beta-lactamases. During the study period, the frequency of S. Typhimurium and S. Arizonae isolations decreased, but with the increase in S. Enteritidis and other NTS. A total of 42 NTS isolates were subjected to WGS and explored for virulence-related traits and the corresponding genetic elements. Some virulence and genetic factors were shared by all NTS serotypes, while the main differences were attributed to the serotype-specific diversity of virulence genes, SPIs, virulence plasmids, and phages. The results indicated the variability and dynamics in the epidemiology of salmonellosis and a high virulence potential of human NTS isolates circulating in the region.

Authors: Anahit Sedrakyan, Zhanna Ktsoyan, Karine Arakelova, Zaruhi Gevorgyan, Magdalina Zakharyan, Shoghik Hakobyan, Alvard Hovhannisyan, Arsen Arakelyan, Rustam Aminov

Date Published: 18th Aug 2022

Publication Type: Journal

Abstract (Expand)

During spaceflight, astronauts are exposed to various physiological and psychological stressors that have been associated with adverse health effects. Therefore, there is an unmet need to develop novel … diagnostic tools to predict early alterations in astronauts' health. Small nucleolar RNA (snoRNA) is a type of short non-coding RNA (60-300 nucleotides) known to guide 2'-O-methylation (Nm) or pseudouridine (ψ) of ribosomal RNA (rRNA), small nuclear RNA (snRNA), or messenger RNA (mRNA). Emerging evidence suggests that dysregulated snoRNAs may be key players in regulating fundamental cellular mechanisms and in the pathogenesis of cancer, heart, and neurological disease. Therefore, we sought to determine whether the spaceflight-induced snoRNA changes in astronaut's peripheral blood (PB) plasma extracellular vesicles (PB-EV) and peripheral blood mononuclear cells (PBMCs). Using unbiased small RNA sequencing (sRNAseq), we evaluated changes in PB-EV snoRNA content isolated from astronauts (n = 5/group) who underwent median 12-day long Shuttle missions between 1998 and 2001. Using stringent cutoff (fold change > 2 or log2-fold change >1, FDR < 0.05), we detected 21 down-and 9-up-regulated snoRNAs in PB-EVs 3 days after return (R + 3) compared to 10 days before launch (L-10). qPCR validation revealed that SNORA74A was significantly down-regulated at R + 3 compared to L-10. We next determined snoRNA expression levels in astronauts' PBMCs at R + 3 and L-10 (n = 6/group). qPCR analysis further confirmed a significant increase in SNORA19 and SNORA47 in astronauts' PBMCs at R + 3 compared to L-10. Notably, many downregulated snoRNA-guided rRNA modifications, including four Nms and five ψs. Our findings revealed that spaceflight induced changes in PB-EV and PBMCs snoRNA expression, thus suggesting snoRNAs may serve as potential novel biomarkers for monitoring astronauts' health. Keywords: astronaut; biomarker; extracellular vesicles; peripheral blood—mononuclear cells; snoRNA. Copyright © 2022 Rai, Rajan, Bisserier, Brojakowska, Sebastian, Evans, Coleman, Mills, Arakelyan, Uchida, Hadri, Goukassian and Garikipati.

Authors: Amit Kumar Rai, K. Shanmugha Rajan, Malik Bisserier, Agnieszka Brojakowska, Aimy Sebastian, Angela C. Evans, Matthew A. Coleman, Paul J. Mills, Arsen Arakelyan, Shizuka Uchida, Lahouaria Hadri, David A. Goukassian, Venkata Naga Srikanth Garikipati

Date Published: 24th Jun 2022

Publication Type: Journal

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