Project description:The species Campylobacter jejuni is naturally competent for DNA uptake; nevertheless, nonnaturally transformable strains do exist. For a subset of strains we previously showed that a periplasmic DNase, encoded by dns, inhibits natural transformation in C. jejuni. In the present study, genetic factors coding for DNase activity in absence of dns were identified. DNA arrays indicated that nonnaturally transformable dns-negative strains contain putative DNA/RNA non-specific endonucleases encoded by CJE0566 and CJE1441 of strain RM1221. These genes are located on C. jejuni integrated element 2 and 4. Expression of CJE0566 and CJE1441 from strain RM1221 and a homologous gene from strain 07479 in DNase-negative Escherichia coli and C. jejuni strains indicated that these genes code for DNases. Genetic transfer of the genes to a naturally transformable C. jejuni strain resulted in a decreased efficiency of natural transformation. Modelling suggests that the C. jejuni DNases belong to the Serratia nuclease family. Overall, the data indicate that the acquisition of prophage encoded DNA/RNA non-specific endonucleases inhibits the natural transformability of C. jejuni through hydrolysis of DNA. The genomic diversity of 15 naturally competent or nonnaturally transformable Campylobacter jejuni strains were examined by microarray-based comparative genomic indexing (CGI) analysis. The CGI analysis allowed the assessment of CDS content for each C. jejuni strain relative to the C. jejuni DNA microarray, which comprises ORFs from strains NCTC 11168, RM1221. ORFs were spotted in duplicate. Genomic DNA from strains NCTC 11168/RM1221 were used as a reference DNA and competitively hybridized with genomic DNA from each of the other C. jejuni strains. Two replicates for each strain were performed. Data normalization was performed as in Parker et al. J Clin Microbiol 2006, 44(11):4125-4135.
Project description:The impact of dietary Chlorella vulgaris and carbohydrate-active enzymes (CAZymes) on the gut of weaned piglets was investigated using an integrated NMR-metabolomics and LC-MS/MS proteomics approach.
Project description:We classified samples and deciphered a key genes signature of intratumor heterogeneity by Principal Component Analysis and Weighted Gene Co-expression Network Analysis. At the genome level, we identified common GB copy number alterations and but a strong inter-individual molecular heterogeneity.
Project description:A Cartes d'Identite des Tumeurs (CIT) project from the french Ligue Nationale Contre le Cancer (http://cit.ligue-cancer.net: Oligodendroglial tumours (OT) are a heterogeneous group of gliomas. Three molecular subgroups are currently distinguished based on the IDH mutation and the 1p/19q co-deletion. Here we performed an integrated analysis of the transcriptome, genome and methylome of 156 OT. Beyond the 3 well-known molecular classes, our multi-omics classification revealed 3 subgroups within 1p/19q co-deleted tumours, associated with different expression patterns of oligodendroglial progenitor cell (OPC), astrocytic, oligodendrocytic and neuronal lineage genes. The validity of these 3 subgroups was confirmed on public datasets. The OPC-like group was associated with a more aggressive histological and genomic profile and with MYC activation that occurred through various alterations including MYC locus genomic gain, MYC exon 3 hypo-methylation and down-regulation of microRNA-34b/c. In the lower grade glioma TCGA dataset, the OPC-like group was associated with a poorer outcome independently from histological grade. Our study unravels previously unrecognized heterogeneity among 1p/19q co-deleted tumours.
Project description:Here we examine key regulatory pathways underlying the transition from compensated hypertrophy (HYP) to decompensated heart failure (HF) and sudden cardiac death (SCD) in a guinea pig model by integrated multi-ome analysis. Relative protein abundances from sham-operated, HYP and HF hearts were assessed by iTRAQ shotgun LC-MS/MS. Metabolites were quantified by LC-MS/MS or GC-MS. Transcriptome profiles were obtained using DNA microarrays. The guinea pig HF proteome exhibited classic biosignatures of cardiac HYP, left ventricular dysfunction, fibrosis, inflammation and extravasation. Fatty acid metabolism, mitochondrial transcription/translation factors, antioxidant enzymes, and other mitochondrial processes, were downregulated in HF, but not HYP. Proteins upregulated in HF implicate extracellular matrix remodeling, cytoskeletal remodeling, and acute phase inflammation markers. Among metabolites, downregulation of acyl-carnitines was observed in HYP, while fatty acids accumulated in HF. Correlation of transcript and protein changes in HF is weak (R2=0.23), suggesting transcript/proteome divergence may reveal post-transcriptional gene regulation in HF. Proteome/Metabolome integration suggests metabolic bottlenecks in fatty acyl-CoA processing by carnitine palmitoyl transferase (CPT1B) as well as TCA cycle inhibition. We present a model by which acute signaling in HF, including Ca2+ dysregulation and low cAMP levels, is coupled to mitochondrial metabolic and antioxidant defects, through a CREB/PGC1 transcriptional axis. Animal Model The guinea pig model of heart failure and sudden cardiac death has been described previously. Briefly, the HF and SCD guinea pig model was produced by combining ascending aortic constriction (AC) and daily isoproterenol challenge (ACi model). Specifically, Hartley guinea pigs (~250 g; Hilltop Lab Animals) were anesthetized with 4% isoflurane in a closed box for 4min, and then intubated and ventilated with oxygen and 2% isoflurane. Ascending aortic constriction (AC) was produced by tying a suture around the ascending aorta using an 18‐gauge needle as a spacer, which was then removed. For sham operations the procedure was identical though the suture was not tied. After the procedure, bupronex (0.05 mg/kg) was administered via intramuscular injection for analgesia and animals were observed until full recovery. Isoproterenol was administered daily by intra peritoneal injection at 1 mg/kg for the first week after surgery and at 2 mg/kg for a subsequent 3 weeks. As characterized previously (1), cardiac function of ACi animal is well compensated in the first 2 weeks (HYP) but declined rapidly thereafter (HF). Hypertrophic heart was collected between 1-2 weeks post-surgery (ACi-2w), whereas failing heart was collected at 4 weeks after surgery (ACi-4w). Following retrograde perfusion with 20ml Tyrode’s solution, excised hearts were Snap-frozen in liquid N2 and stored at -80°C Experimental Design The experiment consisted of 3 treatment groups: 1) HYP (ACi-2wk), 2) HF (ACi-4wk) 3) sham-operated animals with daily administration for 4 weeks (Shami-4w). 1 heart from each group was included in an iTRAQ 4-plex experiment wherein peptides from each heart are subjected to reaction with an isobaric label. The experiment was repeated twice, yielding a total of 3 independent experiments quantifying the peptides from 9 hearts. ITRAQ reagents were shuffled among treatment groups for each experiment to minimize labeling bias.
Project description:Several studies have shown that negative and positive miRNA-mRNA correlations are symmetrically distributed. While negative correlations are consistent with a faster degradation of miRNA targets, the presence of positive correlations suggests bidirectional interactions between the two classes of molecules. However, a comprehensive study of miRNA and mRNA correlations is lacking. A homogeneous map of miRNA and mRNA relationships was obtained by multidimensional scaling (MDS) applied to a single matrix including both heterologous (miRNA-mRNA) and homologous (miRNA-miRNA and mRNA-mRNA) correlations. Liver samples were obtained from 4 patients with HBV-associated acute liver failure (ALF), 10 liver donors and 7 subjects who underwent hepatic resection for liver angioma. This dataset is part of the TransQST collection.
Project description:To identify substrates of the ubiquitinating E3 enzyme Rsp5 we applied purified Rsp5 to duplicate protein arrays. The Rsp proteins were expressed as fusion proteins to GST. We used as a control Ubr1, a RING domain containing E3 ligase We analyzed Rsp5 from S.cerevisiae on duplicate arrays, with four control chips, two without Rsp5 and two with Ubr1.
Project description:This is a dataset of integrated high quality mouse expression data generated on affymetrix Mouse430_2 platform. The original data were selected from ArrayExpress. Please refer to the original ArrayExpress experiments to find additional details.
Project description:The combination of multi-omic techniques, e.g. genomics, transcriptomics, proteomics, metabolomics and epigenomics has revolutionised studies in medical research. These are employed to support biomarker discovery, better understand molecular pathways and identify novel drug targets. Despite concerted efforts in integrating omic datasets, there is an absence for the integration of all four biomolecules in a single extraction protocol. Here, we demonstrate for the first time a novel, minimally destructive integrated protocol for the simultaneous extraction of artificially degraded DNA, proteins, lipids and metabolites from pig brain samples. We used an MTBE-based approach to separate lipids and metabolites, followed by subsequent isolation of DNA and proteins. We have validated this protocol against standalone extraction protocols and show comparable or higher yield of all four biomolecules. This integrated protocol is key towards facilitating preservation of irreplaceable samples while promoting downstream analyses and successful data integration by removing bias from univariate dataset noise and varied distribution characteristics. Keywords: deg