Tissue-specific comparison of gene expression levels in T65H translocation mice, either with or without uniparental duplications of Chrs 7 & 11. Identification of highly differentially expressed transcripts.
Chromosome-wide identification of novel imprinted genes using microarrays and uniparental disomies.
Specimen part
View SamplesComparison of gene expression levels between MatDp(dist2) and PatDp(dist2) mice (newborn whole head). Identification of highly differentially expressed transcripts.
Transcript- and tissue-specific imprinting of a tumour suppressor gene.
Specimen part
View SamplesThe transcriptional responses of human hosts towards influenza viral pathogens are important for understanding virus-mediated immunopathology. Despite great advances gained through studies using model organisms, the complete temporal host transcriptional responses in a natural human system are poorly understood. In a human challenge study using live influenza (H3N2/Wisconsin) viruses, we conducted a clinically uninformed (unsupervised) factor analysis on gene expression profiles and established an ab initio molecular signature that strongly correlates to symptomatic clinical disease. This is followed by the identification of 42 biomarkers whose expression patterns best differentiate early from late phases of infection. In parallel, a clinically informed (supervised) analysis revealed over-stimulation of multiple viral sensing pathways in symptomatic hosts and linked their temporal trajectory with development of diverse clinical signs and symptoms. The resultant inflammatory cytokine profiles were shown to contribute to the pathogenesis because their significant increase preceded disease manifestation by 36 hours. In subclinical asymptomatic hosts, we discovered strong transcriptional regulation of genes involved in inflammasome activation, genes encoding virus interacting proteins, and evidence of active anti-oxidant and cell-mediated innate immune response. Taken together, our findings offer insights into influenza virus-induced pathogenesis and provide a valuable tool for disease monitoring and management in natural environments.
Temporal dynamics of host molecular responses differentiate symptomatic and asymptomatic influenza a infection.
Specimen part
View SamplesPurpose: Human papilloma virus (HPV) associated head and neck squamous cell carcinoma (HNSCC) has a better prognosis than HPV(-) negative cancer. This may be due, in part, to the higher number of tumour infiltrating lymphocytes (TIL) in HPV(+) tumours. We used RNAseq to evaluate whether these differences in clinical behaviour could be explained simply by a numerical difference in TILs or whether there was a fundamental difference between TILs in these two settings. Patients and methods: Twenty-three consecutive HNSCC cases with high and moderate TIL density were subjected to RNAseq analysis. Differentially expressed genes (DEG) between 10 HPV(+) and 13 HPV(-) tumours were identified with EdgeR. Immune subset analysis was performed using, FAIME (Functional Analysis of Individual Microarray Expression) and Immune gene transcript count analysis. Results: 1634 genes were differentially expressed. There was a dominant immune signature in HPV(+) tumours. After normalizing expression profiles for numerical differences in T cells and B cells, 437 significantly DEGs still remained. A B-cell associated signature emerged, which segregated HPV(+) from HPV(-) cancers and included CD200, STAG3, GGA2, SPIB and ADAM28. Differential expression of these genes was confirmed by real-time quantitative PCR and immunohistochemistry. Conclusion: In our dataset, the difference associated with T-cells between patients with HPV(+) and (-) HNSCC was predominantly numerical. However, when TIL numbers are corrected, a distinct differential B-cell signature was revealed. Overall design: mRNA profiles of 10 HPV driven (HPV+) and 13 HPV independant (HPV-) head and neck squamous cell carcinoma (HNSCC) tumours were generated by RNA-Seq, using Illumina HiSeq 2000.
HPV, tumour metabolism and novel target identification in head and neck squamous cell carcinoma.
No sample metadata fields
View SamplesGlycerol is an attractive feedstock for biofuels since it accumulates as a byproduct during biodiesel operations; hence, it is interesting to consider converting glycerol to hydrogen using the formate hydrogen lyase system of Escherichia coli which converts pyruvate to hydrogen. Starting with Escherichia coli BW25113 frdC that lacks fumarate reductase to eliminate the negative effect of accumulated hydrogen on glycerol fermentation and by using both adaptive evolution and chemical mutagenesis combined with a selection method based on increased growth on glycerol, we obtained an improved strain, HW2, that produces 20-fold more hydrogen in glycerol medium (0.68 mmol/L/h) compared to that of frdC mutant. HW2 also grows 5-fold faster (0.25 1/h) than BW25113 frdC on glycerol, so it achieves a reasonable growth rate. Corroborating the increase in hydrogen production, glycerol dehydrogenase activity in HW2 increased 4-fold compared to BW25113 frdC. In addition, a whole-transcriptome study revealed that several pathways that would decrease hydrogen yields were repressed in HW2 (fbp, focA, and gatYZ) while a beneficial pathway, eno which encodes enolase was induced.
An evolved Escherichia coli strain for producing hydrogen and ethanol from glycerol.
No sample metadata fields
View SamplesAcetylation of lysine residues is conserved in all three kingdoms; however, its role in prokaryotes is unknown. Here we demonstrate that acetylation enables the reference bacterium Escherichia coli to withstand environmental stress. Specifically, the bacterium reaches higher cell densities and becomes more resistant to heat and oxidative stress when its proteins are acetylated, as shown by deletion of the gene encoding acetyltransferase YfiQ and the gene encoding deacetylase CobB, as well as by overproducing YfiQ and CobB. Furthermore, we show that the increase in oxidative stress resistance with acetylation is due to the induction of catalase activity through enhanced katG expression. We also found that two-component system proteins CpxA, PhoP, UvrY, and BasR are associated with cell catalase activity and may be responsible as the connection between bacterial acetylation and the stress response. This is the first demonstration of a specific environmental role of acetylation in prokaryotes.
Protein acetylation in prokaryotes increases stress resistance.
Treatment
View SamplesMicroarray analysis for the biofilm cells of Pseudomonas aeruginosa PA14 wild-type vs the tpbA (PA14_13660) mutant in LB medium at 4 and 7 h at 37C
Connecting quorum sensing, c-di-GMP, pel polysaccharide, and biofilm formation in Pseudomonas aeruginosa through tyrosine phosphatase TpbA (PA3885).
No sample metadata fields
View SamplesTo identify the difference of gene expression in barley upon P. aeruginosa PAO1 and less pathogenic PA5021 mutant
Potassium and sodium transporters of Pseudomonas aeruginosa regulate virulence to barley.
No sample metadata fields
View SamplesPersisters are cells which evade stresses like antibiotics and which are characterized by reduced metabolism and a lack of genetic alterations required to achieve this state. We showed previously that MqsR and MqsA of Escherichia coli are a toxin-antitoxin pair that influence cell physiology (e.g., biofilm formation and motility) via RNase activity as well as through regulation of toxin CspD. Here, we show that deletion of the mqsRA locus decreases persister cell formation and, consistent with this result, overexpression of MqsR increases persister cell formation. Furthermore, toxins Hha, CspD, and HokA increase persister cell formation. In addition, by overproducing MqsR in a series of isogenic mutants, we show that Hha and CspD are necessary for persister cell formation via MqsR overexpression. Surprisingly, Hfq, a small RNA chaperone, decreases persistence. A whole-transcriptome study shows that Hfq induces transport-related genes (oppA, oppB, oppC, oppD, oppF, and dppA), outer membrane protein-related genes (ybfM and ybfN), toxins (hha), and proteases (clpX, clpP, and lon). Taken together, these results indicate that toxins CspD and Hha influence persister cell formation via MqsR and that Hfq plays an important role in the regulation of persister cell formation via regulation of transport or outer membrane proteins.
Toxins Hha and CspD and small RNA regulator Hfq are involved in persister cell formation through MqsR in Escherichia coli.
No sample metadata fields
View SamplesAntitoxins are becoming recognized as proteins that regulate more than their own synthesis; for example, we found previously that antitoxin MqsA represses the gene encoding the stationary phase sigma factor RpoS. Here, we investigated the physiological role of antitoxin DinJ of the DinJ/YafQ toxin/antitoxin system and found DinJ also affects the general stress response by decreasing RpoS levels. Corroborating the reduced RpoS levels upon producing DinJ, catalase activity, cell adhesins, and cyclic diguanylate decreased while swimming increased. Using a transcriptome search and DNA-binding assays, we determined that the mechanism by which DinJ reduces RpoS is by repressing cspE which encodes cold-shock protein CspE that inhibits translation of rpoS mRNA. Hence, DinJ influences the general stress response indirectly by regulating cspE.
Antitoxin DinJ influences the general stress response through transcript stabilizer CspE.
Time
View Samples