97 research outputs found

    Shuffling of cis-regulatory elements is a pervasive feature of the vertebrate lineage

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    BACKGROUND: All vertebrates share a remarkable degree of similarity in their development as well as in the basic functions of their cells. Despite this, attempts at unearthing genome-wide regulatory elements conserved throughout the vertebrate lineage using BLAST-like approaches have thus far detected noncoding conservation in only a few hundred genes, mostly associated with regulation of transcription and development. RESULTS: We used a unique combination of tools to obtain regional global-local alignments of orthologous loci. This approach takes into account shuffling of regulatory regions that are likely to occur over evolutionary distances greater than those separating mammalian genomes. This approach revealed one order of magnitude more vertebrate conserved elements than was previously reported in over 2,000 genes, including a high number of genes found in the membrane and extracellular regions. Our analysis revealed that 72% of the elements identified have undergone shuffling. We tested the ability of the elements identified to enhance transcription in zebrafish embryos and compared their activity with a set of control fragments. We found that more than 80% of the elements tested were able to enhance transcription significantly, prevalently in a tissue-restricted manner corresponding to the expression domain of the neighboring gene. CONCLUSION: Our work elucidates the importance of shuffling in the detection of cis-regulatory elements. It also elucidates how similarities across the vertebrate lineage, which go well beyond development, can be explained not only within the realm of coding genes but also in that of the sequences that ultimately govern their expression

    Identification of downstream effectors of retinoic acid specifying the zebrafish pancreas by integrative genomics.

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    Retinoic acid (RA) is a key signal for the specification of the pancreas. Still, the gene regulatory cascade triggered by RA in the endoderm remains poorly characterized. In this study, we investigated this regulatory network in zebrafish by combining RNA-seq, RAR ChIP-seq and ATAC-seq assays. By analysing the effect of RA and of the RA receptor (RAR) inverse-agonist BMS493 on the transcriptome and on the chromatin accessibility of endodermal cells, we identified a large set of genes and regulatory regions regulated by RA signalling. RAR ChIP-seq further defined the direct RAR target genes in zebrafish, including hox genes as well as several pancreatic regulators like mnx1, insm1b, hnf1ba and gata6. Comparison of zebrafish and murine RAR ChIP-seq data highlighted the conserved direct target genes and revealed that some RAR sites are under strong evolutionary constraints. Among them, a novel highly conserved RAR-induced enhancer was identified downstream of the HoxB locus and driving expression in the nervous system and in the gut in a RA-dependent manner. Finally, ATAC-seq data unveiled the role of the RAR-direct targets Hnf1ba and Gata6 in opening chromatin at many regulatory loci upon RA treatment

    The TATA-binding protein regulates maternal mRNA degradation and differential zygotic transcription in zebrafish

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    Early steps of embryo development are directed by maternal gene products and trace levels of zygotic gene activity in vertebrates. A major activation of zygotic transcription occurs together with degradation of maternal mRNAs during the midblastula transition in several vertebrate systems. How these processes are regulated in preparation for the onset of differentiation in the vertebrate embryo is mostly unknown. Here, we studied the function of TATA-binding protein (TBP) by knock down and DNA microarray analysis of gene expression in early embryo development. We show that a subset of polymerase II-transcribed genes with ontogenic stage-dependent regulation requires TBP for their zygotic activation. TBP is also required for limiting the activation of genes during development. We reveal that TBP plays an important role in the degradation of a specific subset of maternal mRNAs during late blastulation/early gastrulation, which involves targets of the miR-430 pathway. Hence, TBP acts as a specific regulator of the key processes underlying the transition from maternal to zygotic regulation of embryogenesis. These results implicate core promoter recognition as an additional level of differential gene regulation during development

    A Multicassette Gateway Vector Set for High Throughput and Comparative Analyses in Ciona and Vertebrate Embryos

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    BACKGROUND: The past few years have seen a vast increase in the amount of genomic data available for a growing number of taxa, including sets of full length cDNA clones and cis-regulatory sequences. Large scale cross-species comparisons of protein function and cis-regulatory sequences may help to understand the emergence of specific traits during evolution. PRINCIPAL FINDINGS: To facilitate such comparisons, we developed a Gateway compatible vector set, which can be used to systematically dissect cis-regulatory sequences, and overexpress wild type or tagged proteins in a variety of chordate systems. It was developed and first characterised in the embryos of the ascidian Ciona intestinalis, in which large scale analyses are easier to perform than in vertebrates, owing to the very efficient embryo electroporation protocol available in this organism. Its use was then extended to fish embryos and cultured mammalian cells. CONCLUSION: This versatile vector set opens the way to the mid- to large-scale comparative analyses of protein function and cis-regulatory sequences across chordate evolution. A complete user manual is provided as supplemental material

    Bocepreviralapú hármas kezelés hatékonyságának és biztonságosságának retrospektív elemzése előrehaladott fibrosisstádiumú, hepatitis C-vírus 1-es genotípussal fertőzött, korábban sikertelenül kezelt magyar betegeknél

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    INTRODUCTION: During 2011 and 2013, 155 Hungarian hepatitis C genotype 1 infected patients, mostly with advanced liver fibrosis, who did not respond to prior peginterferon + ribavirin dual therapy, started boceprevir based triple therapy in an early access program. AIM AND METHOD: Efficacy and safety of the therapy was retrospectively assessed based on sustained virologic responses, as well as on frequency and type of serious adverse events and of those leading to therapy discontinuation. RESULTS: In an intent-to-treat analysis 39.4% patients (61/155) reached sustained virologic response. Amongst pervious relapsers, partial responders and null-responders 59.5%, 41.4 % and 22.9% (p<0.05 compared to the other two categories) reached sustained virologic response, respectively, while amongst non-cirrhotics and cirrhotics 52.5% and 31.3% (p<0.05 compared to the non-cirrhotics) achieved sutained virologic response, respectively. Six out of the 33 most difficult to cure patients (previous null responder and cirrhotic) have reached sustained virologic response (18.2%). Frequency of early discontinuations due to insufficient virologic response was 31.1%, while due to adverse event 10.3%. Reported frequency of serious adverse event was 9.8%. These events represented anemia, diarrhoea, depression, agranulocytosis, elevated aminotransferases, generalized dermatitis and severe gingivitis with loss of teeth, prolonged QT interval on ECG, generalized oedema and severe dyspnoea, uroinfection, exacerbation of Crohn's disease, Campylobacter pylori infection and unacceptable weakness and fatigue. Eight patients received transfusion, 4 patients erythropoietin and 1 granulocyte colony stimulating factor during therapy. No death has been reported. CONCLUSIONS: With boceprevir based triple therapy, one of the bests available in 2011-2013 in Hungary, a relevant proportion of hepatitis C infected patients with advanced liver fibrosis achieved sustained viral response. In this cohort, side-effects resembled those reported in registration studies, and resulted in therapy discontinuation with consequent treatment failure in a relevant number of patients. Efficacy and tolerability of boceprevir-based triple therapy are suboptimal, particularly in the most difficult to cure patient population. Orv. Hetil., 2016, 157(34), 1366-1374

    CDK2 and PKA Mediated-Sequential Phosphorylation Is Critical for p19INK4d Function in the DNA Damage Response

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    DNA damage triggers a phosphorylation-based signaling cascade known as the DNA damage response. p19INK4d, a member of the INK4 family of CDK4/6 inhibitors, has been reported to participate in the DNA damage response promoting DNA repair and cell survival. Here, we provide mechanistic insight into the activation mechanism of p19INK4d linked to the response to DNA damage. Results showed that p19INK4d becomes phosphorylated following UV radiation, β-amyloid peptide and cisplatin treatments. ATM-Chk2/ATR-Chk1 signaling pathways were found to be differentially involved in p19INK4d phosphorylation depending on the type of DNA damage. Two sequential phosphorylation events at serine 76 and threonine 141 were identified using p19INK4d single-point mutants in metabolic labeling assays with 32P-orthophosphate. CDK2 and PKA were found to participate in p19INK4d phosphorylation process and that they would mediate serine 76 and threonine 141 modifications respectively. Nuclear translocation of p19INK4d induced by DNA damage was shown to be dependent on serine 76 phosphorylation. Most importantly, both phosphorylation sites were found to be crucial for p19INK4d function in DNA repair and cell survival. In contrast, serine 76 and threonine 141 were dispensable for CDK4/6 inhibition highlighting the independence of p19INK4d functions, in agreement with our previous findings. These results constitute the first description of the activation mechanism of p19INK4d in response to genotoxic stress and demonstrate the functional relevance of this activation following DNA damage

    Prospective, Multicentre, Nationwide Clinical Data from 600 Cases of Acute Pancreatitis

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    OBJECTIVE: The aim of this study was to analyse the clinical characteristics of acute pancreatitis (AP) in a prospectively collected, large, multicentre cohort and to validate the major recommendations in the IAP/APA evidence-based guidelines for the management of AP. DESIGN: Eighty-six different clinical parameters were collected using an electronic clinical research form designed by the Hungarian Pancreatic Study Group. PATIENTS: 600 adult patients diagnosed with AP were prospectively enrolled from 17 Hungarian centres over a two-year period from 1 January 2013. MAIN RESULTS: With respect to aetiology, biliary and alcoholic pancreatitis represented the two most common forms of AP. The prevalence of biliary AP was higher in women, whereas alcoholic AP was more common in men. Hyperlipidaemia was a risk factor for severity, lack of serum enzyme elevation posed a risk for severe AP, and lack of abdominal pain at admission demonstrated a risk for mortality. Abdominal tenderness developed in all the patients with severe AP, while lack of abdominal tenderness was a favourable sign for mortality. Importantly, lung injury at admission was associated with mortality. With regard to laboratory parameters, white blood cell count and CRP were the two most sensitive indicators for severe AP. The most common local complication was peripancreatic fluid, whereas the most common distant organ failure in severe AP was lung injury. Deviation from the recommendations in the IAP/APA evidence-based guidelines on fluid replacement, enteral nutrition and timing of interventions increased severity and mortality. CONCLUSIONS: Analysis of a large, nationwide, prospective cohort of AP cases allowed for the identification of important determinants of severity and mortality. Evidence-based guidelines should be observed rigorously to improve outcomes in AP

    The European and Hungarian results of cage culture of fish

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    After a brief history of the cage culture of fish in Europe, the results of cage culture experiments in Hungary are presented with particular reference to the cage cultures of wels, Silurus glanis , bester (hybrid of Huso huso and Acinpenser ruthenus) and the common carp Cyprinus carpio
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