12 research outputs found
A new set of 16S rRNA universal primers for identification 1 of animal species
In this study, bioinformatics were used to specifically design universal primers within 16S rRNA gene according to the following criteria: the priming sites needed to be sufficiently conserved to permit a reliable amplification (pooled samples) and the genetic marker needed to (a) be sufficiently variable to discriminate among most species and sufficiently conserved within than between species, (b) be short enough to allow also accurate amplification from processed samples (food) and non-invasive approaches (fur, feathers, faeces, etc.) (c) convey sufficient information to assign samples to species and (d) be amplified under variable lab conditions and protocols. Furthermore, short sequences allow the accurate massive inter- and intra-species identification of point mutations by the SSCP technique. The size of the amplified segment ranged from 222 to 252 bp. Amplification and identification success were 100% with all kinds of tissue tested in both raw and processed samples in a wind range of species, mammals (n = 27), fishes (n = 32) birds (n = 19), coleoptera (n = 23), reptiles (n = 5), crustaceans (n = 5) and cephalopods (n = 2), including almost all European mammal and avian game species. In addition, no intra-specific polymorphism was detected. Finally, gene fragments, homologous to those amplified by the primers used herein and retrieved from the GenBank for three animal sets [mammals (n = 248), birds (n = 231) and fishes (n = 644)] showed a particular precise percentage of correct identifications. Therefore, this short segment of the 16S rRNA mitochondrial gene could be a good candidate for a rapid, accurate, low-cost and easy-to-apply and interpret method to identify mammal and avian game species by PCR amplification and sequencing that can be easily incorporated in integrated conservation and forensic programmes
PlasmiR: A Manual Collection of Circulating microRNAs of Prognostic and Diagnostic Value
Only recently, microRNAs (miRNAs) were found to exist in traceable and distinctive amounts in the human circulatory system, bringing forth the intriguing possibility of using them as minimally invasive biomarkers. miRNAs are short non-coding RNAs that act as potent post-transcriptional regulators of gene expression. Extensive studies in cancer and other disease landscapes investigate the protective/pathogenic functions of dysregulated miRNAs, as well as their biomarker potential. A specialized resource amassing experimentally verified, circulating miRNA biomarkers does not exist. We queried the existing literature to identify articles assessing diagnostic/prognostic roles of miRNAs in blood, serum, or plasma samples. Articles were scrutinized in order to exclude instances lacking sufficient experimental documentation or employing no biomarker assessment methods. We incorporated information from more than 200 biomedical articles, annotating crucial meta-information including cohort sizes, inclusion-exclusion criteria, disease/healthy confirmation methods and quantification details. miRNAs and diseases were systematically characterized using reference resources. Our circulating miRNA biomarker collection is provided as an online database, plasmiR. It consists of 1021 entries regarding 251 miRNAs and 112 diseases. More than half of plasmiRās entries refer to cancerous and neoplastic conditions, 183 of them (32%) describing prognostic associations. plasmiR facilitates smart queries, emphasizing visualization and exploratory modes for all researchers
A Poly(Lactic-co-Glycolic) Acid Nanovaccine Based on Chimeric Peptides from Different Leishmania infantum Proteins Induces Dendritic Cells Maturation and Promotes Peptide-Specific IFNĪ³-Producing CD8+ T Cells Essential for the Protection against Experimental Visceral Leishmaniasis
Visceral leishmaniasis, caused by Leishmania (L.) donovani and L. infantum protozoan parasites, can provoke overwhelming and protracted epidemics, with high case-fatality rates. An effective vaccine against the disease must rely on the generation of a strong and long-lasting T cell immunity, mediated by CD4+ TH1 and CD8+ T cells. Multi-epitope peptide-based vaccine development is manifesting as the new era of vaccination strategies against Leishmania infection. In this study, we designed chimeric peptides containing HLA-restricted epitopes from three immunogenic L. infantum proteins (cysteine peptidase A, histone H1, and kinetoplastid membrane protein 11), in order to be encapsulated in poly(lactic-co-glycolic) acid nanoparticles with or without the adjuvant monophosphoryl lipid A (MPLA) or surface modification with an octapeptide targeting the tumor necrosis factor receptor II. We aimed to construct differentially functionalized peptide-based nanovaccine candidates and investigate their capacity to stimulate the immunomodulatory properties of dendritic cells (DCs), which are critical regulators of adaptive immunity generated upon vaccination. According to our results, DCs stimulation with the peptide-based nanovaccine candidates with MPLA incorporation or surface modification induced an enhanced maturation profile with prominent IL-12 production, promoting allogeneic T cell proliferation and intracellular production of IFNĪ³ by CD4+ and CD8+ T cell subsets. In addition, DCs stimulated with the peptide-based nanovaccine candidate with MPLA incorporation exhibited a robust transcriptional activation, characterized by upregulated genes indicative of vaccine-driven DCs differentiation toward type 1 phenotype. Immunization of HLA A2.1 transgenic mice with this peptide-based nanovaccine candidate induced peptide-specific IFNĪ³-producing CD8+ T cells and conferred significant protection against L. infantum infection. Concluding, our findings supported that encapsulation of more than one chimeric multi-epitope peptides from different immunogenic L. infantum proteins in a proper biocompatible delivery system with the right adjuvant is considered as an improved promising approach for the development of a vaccine against VL
Impact of Helicobacter pylori Infection and Its Major Virulence Factor CagA on DNA Damage Repair
Helicobacter pylori infection induces a plethora of DNA damages. Gastric epithelial cells, in order to maintain genomic integrity, require an integrous DNA damage repair (DDR) machinery, which, however, is reported to be modulated by the infection. CagA is a major H. pylori virulence factor, associated with increased risk for gastric carcinogenesis. Its pathogenic activity is partly regulated by phosphorylation on EPIYA motifs. Our aim was to identify effects of H. pylori infection and CagA on DDR, investigating the transcriptome of AGS cells, infected with wild-type, ΔCagA and EPIYA-phosphorylation-defective strains. Upon RNA-Seq-based transcriptomic analysis, we observed that a notable number of DDR genes were found deregulated during the infection, potentially resulting to base excision repair and mismatch repair compromise and an intricate deregulation of nucleotide excision repair, homologous recombination and non-homologous end-joining. Transcriptome observations were further investigated on the protein expression level, utilizing infections of AGS and GES-1 cells. We observed that CagA contributed to the downregulation of Nth Like DNA Glycosylase 1 (NTHL1), MutY DNA Glycosylase (MUTYH), Flap Structure-Specific Endonuclease 1 (FEN1), RAD51 Recombinase, DNA Polymerase Delta Catalytic Subunit (POLD1), and DNA Ligase 1 (LIG1) and, contrary to transcriptome results, Apurinic/Apyrimidinic Endodeoxyribonuclease 1 (APE1) upregulation. Our study accentuates the role of CagA as a significant contributor of H. pylori infection-mediated DDR modulation, potentially disrupting the balance between DNA damage and repair, thus favoring genomic instability and carcinogenesis
Long non-coding RNAs regulate Aedes aegypti vector competence for Zika virus and reproduction.
Long non-coding RNAs (lncRNAs) play critical regulatory roles in various cellular and metabolic processes in mosquitoes and all other organisms studied thus far. In particular, their involvement in essential processes such as reproduction makes them potential targets for the development of novel pest control approaches. However, their function in mosquito biology remains largely unexplored. To elucidate the role of lncRNAs in mosquitoes' reproduction and vector competence for arboviruses, we have implemented a computational and experimental pipeline to mine, screen, and characterize lncRNAs related to these two biological processes. Through analysis of publicly available Zika virus (ZIKV) infection-regulated Aedes aegypti transcriptomes, at least six lncRNAs were identified as being significantly upregulated in response to infection in various mosquito tissues. The roles of these ZIKV-regulated lncRNAs (designated Zinc1, Zinc2, Zinc3, Zinc9, Zinc10 and Zinc22), were further investigated by dsRNA-mediated silencing studies. Our results show that silencing of Zinc1, Zinc2, and Zinc22 renders mosquitoes significantly less permissive to ZIKV infection, while silencing of Zinc22 also reduces fecundity, indicating a potential role for Zinc22 in trade-offs between vector competence and reproduction. We also found that silencing of Zinc9 significantly increases fecundity but has no effect on ZIKV infection, suggesting that Zinc9 may be a negative regulator of oviposition. Our work demonstrates that some lncRNAs play host factor roles by facilitating viral infection in mosquitoes. We also show that lncRNAs can influence both mosquito reproduction and permissiveness to virus infection, two biological systems with important roles in mosquito vectorial capacity
Agnodice: indexing experimentally supported bacterial sRNA-RNA interactions
ABSTRACTIn the last decade, the immense growth in the field of bacterial small RNAs (sRNAs), along with the biotechnological breakthroughs in Deep Sequencing permitted the deeper understanding of sRNA-RNA interactions. However, microbiology is currently lacking a thoroughly curated collection of this rapidly expanding universe. We present Agnodice (https://dianalab.e-ce.uth.gr/agnodice), our effort to systematically catalog and annotate experimentally supported bacterial sRNA-RNA interactions. Agnodice, for the first time, incorporates thousands of bacterial sRNA-RNA interactions derived from a diverse set of experimental methodologies including state-of-the-art Deep Sequencing interactome identification techniques. It comprises 39,600 entries which are annotated at strain-level resolution and pertain to 399 sRNAs and 12,137 target RNAs identified in 71 bacterial strains. The database content is exclusively experimentally supported, incorporating interactions derived via low yield as well as state-of-the-art high-throughput methods. The entire content of the database is freely accessible and can be directly downloaded for further analysis. Agnodice will serve as a valuable source, enabling microbiologists to form novel hypotheses, design/identify novel sRNA-based drug targets, and explore the therapeutic potential of microbiomes from the perspective of small regulatory RNAs.IMPORTANCEAgnodice (https://dianalab.e-ce.uth.gr/agnodice) is an effort to systematically catalog and annotate experimentally supported bacterial small RNA (sRNA)-RNA interactions. Agnodice, for the first time, incorporates thousands of bacterial sRNA-RNA interactions derived from a diverse set of experimental methodologies including state-of-the-art Next Generation Sequencing interactome identification techniques
PlasmiR: A Manual Collection of Circulating microRNAs of Prognostic and Diagnostic Value
Simple Summary Only recently have the important biomarker capacities of
microRNAs (miRNAs) in blood samples during disease been revealed. miRNAs
are abundantly detected in circulation, and are less prone to
degradation than longer RNA. Details regarding potential discriminatory
miRNAs against numerous pathologic conditions are dispersed across
articles, while existing resources that catalogue miRNA abundance in
blood samples are not tailored to biomarker research. This study
presents the meticulous manual curation of more than 200 articles that
specifically interrogate the biomarker potential of miRNAs in whole
blood, serum, or plasma. This annotation effort resulted in the creation
of plasmiR, a database that systematically provides experimental
evidence for the diagnostic and prognostic potential of circulating
miRNAs against human diseases. plasmiR features 1021 entries,
accompanied by rich study-specific meta-information, and an intuitive
interface that enables the formation of complex queries and
visualizations. Only recently, microRNAs (miRNAs) were found to exist in
traceable and distinctive amounts in the human circulatory system,
bringing forth the intriguing possibility of using them as minimally
invasive biomarkers. miRNAs are short non-coding RNAs that act as potent
post-transcriptional regulators of gene expression. Extensive studies in
cancer and other disease landscapes investigate the
protective/pathogenic functions of dysregulated miRNAs, as well as their
biomarker potential. A specialized resource amassing experimentally
verified, circulating miRNA biomarkers does not exist. We queried the
existing literature to identify articles assessing diagnostic/prognostic
roles of miRNAs in blood, serum, or plasma samples. Articles were
scrutinized in order to exclude instances lacking sufficient
experimental documentation or employing no biomarker assessment methods.
We incorporated information from more than 200 biomedical articles,
annotating crucial meta-information including cohort sizes,
inclusion-exclusion criteria, disease/healthy confirmation methods and
quantification details. miRNAs and diseases were systematically
characterized using reference resources. Our circulating miRNA biomarker
collection is provided as an online database, plasmiR. It consists of
1021 entries regarding 251 miRNAs and 112 diseases. More than half of
plasmiRās entries refer to cancerous and neoplastic conditions, 183 of
them (32%) describing prognostic associations. plasmiR facilitates
smart queries, emphasizing visualization and exploratory modes for all
researchers
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DIANA-TarBase v8: a decade-long collection of experimentally supported miRNAāgene interactions
Abstract DIANA-TarBase v8 (http://www.microrna.gr/tarbase) is a reference database devoted to the indexing of experimentally supported microRNA (miRNA) targets. Its eighth version is the first database indexing >1 million entries, corresponding to ā¼670 000 unique miRNA-target pairs. The interactions are supported by >33 experimental methodologies, applied to ā¼600 cell types/tissues under ā¼451 experimental conditions. It integrates information on cell-type specific miRNAāgene regulation, while hundreds of thousands of miRNA-binding locations are reported. TarBase is coming of age, with more than a decade of continuous support in the non-coding RNA field. A new module has been implemented that enables the browsing of interactions through different filtering combinations. It permits easy retrieval of positive and negative miRNA targets per species, methodology, cell type and tissue. An incorporated ranking system is utilized for the display of interactions based on the robustness of their supporting methodologies. Statistics, pie-charts and interactive bar-plots depicting the database content are available through a dedicated result page. An intuitive interface is introduced, providing a user-friendly application with flexible options to different queries
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Radiomic tumor phenotypes augment molecular profiling in predicting recurrence free survival after breast neoadjuvant chemotherapy.
BackgroundEarly changes in breast intratumor heterogeneity during neoadjuvant chemotherapy may reflect the tumor's ability to adapt and evade treatment. We investigated the combination of precision medicine predictors of genomic and MRI data towards improved prediction of recurrence free survival (RFS).MethodsA total of 100 women from the ACRIN 6657/I-SPY 1 trial were retrospectively analyzed. We estimated MammaPrint, PAM50 ROR-S, and p53 mutation scores from publicly available gene expression data and generated four, voxel-wise 3-D radiomic kinetic maps from DCE-MR images at both pre- and early-treatment time points. Within the primary lesion from each kinetic map, features of change in radiomic heterogeneity were summarized into 6 principal components.ResultsWe identify two imaging phenotypes of change in intratumor heterogeneity (pā<ā0.01) demonstrating significant Kaplan-Meier curve separation (pā<ā0.001). Adding phenotypes to established prognostic factors, functional tumor volume (FTV), MammaPrint, PAM50, and p53 scores in a Cox regression model improves the concordance statistic for predicting RFS from 0.73 to 0.79 (pā=ā0.002).ConclusionsThese results demonstrate an important step in combining personalized molecular signatures and longitudinal imaging data towards improved prognosis