Project description:Background: Microorganisms are the major cause of food spoilage during storage, processing and distribution. Pseudomonas fluorescens is a typical spoilage bacterium that contributes to a large extent to the spoilage process of proteinaceous food. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Our previous work revealed that RpoS contributed to the spoilage activities of P. fluorescens by regulating resistance to different stress conditions, extracellular acylated homoserine lactone (AHL) levels, extracellular protease and total volatile basic nitrogen (TVB-N) production. However, RpoS-dependent genes in P. fluorescens remained undefined. Results: RNA-seq transcriptomics analysis combined with quantitative proteomics analysis basing on multiplexed isobaric tandem mass tag (TMT) labeling was performed for the P. fluorescens wild-type strain UK4 and its derivative carrying a rpoS mutation. A total of 375 differentially expressed genes (DEGs) and 212 differentially expressed proteins (DEPs) were identified in these two backgrounds. The DGEs were further verified by qRT-PCR tests, and the genes directly regulated by RpoS were confirmed by 5’-RACE-PCR sequencing. The combining transcriptome and proteome analysis revealed a role of this regulator in several cellular processes, including polysaccharide metabolism, intracellular secretion and extracellular structures, cell well biogenesis, stress responses, ammonia and biogenic amine production, which may contribute to biofilm formation, stress resistance and spoilage activities of P. fluorescens. Moreover, in this work we indeed observed that RpoS contributed to the production of the macrocolony biofilm’s matrix.
Project description:In a previous study, we found that H2S alleviates salinity stress in cucumber by maintaining the Na+/K+ balance and by regulating H2S metabolism and the oxidative stress response. However, little is known about the molecular mechanisms behind H2S-regulated salt-stress tolerance in cucumber. Here, an integrated transcriptomic and proteomic analysis based on RNA-seq and 2-DE was used to investigate the global mechanism underlying H2S-regulated salt-stress tolerance. In total, 11 761 differentially expressed genes (DEGs) and 61 differentially expressed proteins (DEPs) were identified. Analysis of the pathways associated with the DEGs showed that salt stress enriched expression of genes in primary and energy metabolism, such as photosynthesis, carbon metabolism and biosynthesis of amino acids. Application of H2S significantly decreased these DEGs but enriched DEGs related to plant-pathogen interaction, sulfur-containing metabolism, cell defense and signal transduction pathways. Notably, changes related to sulfur-containing metabolism and cell defense were also observed through proteome analysis, such as Cysteine synthase 1, Glutathione S-transferase U25-like, Protein disulfide-isomerase and Peroxidase 2. We present the first global analysis of the mechanism underlying H2S regulation of salt-stress tolerance in cucumber through tracking changes in the expression of specific proteins and genes.
Project description:Over 20% of Earth’s terrestrial surface is underlain by permafrost that represents one of the largest terrestrial carbon pools, with an estimated ~1700 Pg of carbon (C) contained in the upper 3 m of permafrost. Models estimate that C release from thawing permafrost might represent the largest new transfer of C from the biosphere to the atmosphere as the climate warms. Here we investigated microbial community phylogeny, genetic functional potential gene expression, and protein production patterns along a natural thaw gradient, including permafrost, the seasonally thawed active layer and nearby thawed thermokarst bog, using a combination of molecular “omics” approaches: metagenomics (MG), metatranscriptomics (MT) and metaproteomics (MP). Highlights from these analyses reveal energy yielding microbial processes and potential strategies for microbial survival in permafrost soils, and linkages between biogeochemical process rates and –omics measurements. The results provide new knowledge about microbial life and activity potential in permafrost, the potential importance of iron reduction as a survival strategy under frozen conditions in mineral soils, and the importance of methanogenesis following thaw. The multi-omics strategy demonstrated here enables better mechanistic understanding of the ecological strategies utilized by soil microbial communities in response to climate change. Associated metagenomics data available at the EBI Metagenomics portal under the accession number <a href="https://www.ebi.ac.uk/metagenomics/projects/SRP052575">SRP052575</a>.
Project description:Objective To establish whether whole-blood MicroRNA (miRNA) profiles differ between postural tachycardia syndrome (POTS) sufferers and control subjects, and to identify the miRNA that regulate plasma H2S. Study design: High-throughput sequencing was used to obtain whole-blood miRNA expression profiles for five POTS sufferers and five normal children. miRNAs with an adjusted P-value of <0.05 (by DESeq) and with a log2 fold change ≥3 were considered to be differentially expressed (DEmiRNAs). The target genes of the DEmiRNAs were identified using RNAhybrid and miRanda, and only those identified by both were considered. The combined effects of the DEmiRNAs were determined using KEGG pathway analysis. Another 40 POTS and 20 normal patients were used as validation subjects. Plasma H2S was determined with a sulfide electrode, and flow-mediated vasodilation (FMD) was performed with a color Doppler ultrasound system. miRNAs were analyzed using QRT-PCR. Results: Thirteen DEmiRNAs were identified. When P values of 0.01 and 0.05 were used, 198 and 481 genes, respectively, were shown to be targeted by the 13 DEmiRNAs. DEmiRNAs were significantly enriched in 36 pathways (P <.05), in which PI3K/Akt signaling was closely related to vascular function. In the validation subjects, the plasma H2S and FMD was higher in the POTS sufferers, as was the expression level of whole-blood miR-21 (P <.05), which identified POTS patients with a sensitivity of 92.5% and a specificity of 100%. Conclusion: Elevated whole-blood miR-21 levels serve as an indicator for POTS and may explain the increased plasma H2S observed in POTS sufferers.
Project description:Full-Length cDNA transcriptome (Iso-Seq) data sequenced on the PacBio Sequel system using 2.1 chemistry. Multiplexed cDNA library of 12 samples (3 tissues x 4 strains). Tissues: root, embryo, endosperm. Strains: B73, Ki11, B73xKi11, Ki11xB73.
Project description:Background. Chronic fatiguing illness remains a poorly understood syndrome of unknown pathogenesis. We attempted to identify biomarkers for chronic fatiguing illness using microarrays to query the transcriptome in peripheral blood leukocytes. Methods. Cases were 44 individuals who were clinically evaluated and found to meet standard international criteria for chronic fatigue syndrome or idiopathic chronic fatigue, and controls were their monozygotic co-twins who were clinically evaluated and never had even one month of impairing fatigue. Biological sampling conditions were standardized and RNA stabilizing media were used. These methodological features provide rigorous control for bias resulting from case-control mismatched ancestry and experimental error. Individual gene expression profiles were assessed using Affymetrix Human Genome U133 Plus 2.0 arrays. Findings. There were no significant differences in gene expression for any transcript. Conclusions. Contrary to our expectations, we were unable to identify a biomarker for chronic fatiguing illness in the transcriptome of peripheral blood leukocytes suggesting that positive findings in prior studies may have resulted from experimental bias. Cases were 44 individuals who were clinically evaluated and found to meet standard international criteria for chronic fatigue syndrome or idiopathic chronic fatigue, and controls were their monozygotic co-twins who were clinically evaluated and never had even one month of impairing fatigue.
Project description:Understanding human regulatory T cells (Tregs) heterogeneity may identify markers of disease pathogenesis and facilitate the development of optimized cellular therapeutics. To better elucidate human Treg subsets, we conducted direct transcriptional profiling of CD4+FOXP3+Helios+ thymic-derived Treg (tTreg) and CD4+FOXP3+Helios- peripherally-induced Treg (pTreg), followed by comparison to CD4+FOXP3-Helios- T conventional (Tconv) cells. This analysis revealed that the coinhibitory receptor T-cell immunoglobulin and immunoreceptor tyrosine-based inhibitory motif domain (TIGIT) was highly expressed on tTreg. In this study CD4 T cells were stained for the Treg-associated transcription factors FOXP3 and Helios, and subsequently FACS sorted to yield three populations: tTreg (CD4+FOXP3+Helios+), pTreg (CD4+FOXP3+Helios–) and the reference population Tconv (CD4+FOXP3–Helios–). A direct transcriptional profile was obtained from the recovered RNA from the populations defined as tTreg, pTreg, and Tconv.
Project description:Using DNA microarray as a global approach to understanding the molecular basis of autism, we examined gene expression profiling in peripheral blood from 21 young adults with autism spectrum disorder (ASD) and healthy mothers having children with ASD, between whom there was no blood relationship. Several genes which were significantly changed in the ASD group comparing with their age- and gender-matched healthy subjects were mainly involved in cell morphology, cellular assembly and organization, and nerve system development and function. In addition, mothers having children with ASD possessed a unique gene expression signature shown as significant alterations of protein synthesis despite of their nonautistic diagnostic status. Moreover, an ASD-associated gene expression signature was commonly observed in both individuals with ASD and healthy mothers having children with ASD. Total RNA was prepared from venous blood which was taken from each subject. Gene expression profiling of venous blood from subjects with ASD (21), the healthy women who had children with ASD (21) and their age- and gender-matched healthy subjects (42) were obtained using a whole human genome oligonucleotide microarray (Agilent 44K Human whole genome array G4112F, GPL6480) to measure gene expression in these samples according to the manufacture’s protocol. The one GSM sample of microarray analysis was made by individual subject. Differentially expressed genes were determined across all rationed expression values for age- and gender-matched pairs (ASD vs. control, asdMO vs. ctrlMO) using Genespling analysis.