Project description:Escherichia coli O157:H7 is an important food-borne pathogen that can cause hemorrhagic colitis (HC) and hemolytic-uremic syndrome (HUS) in humans. pO157_Sal, a novel conjugative plasmid is present in a Chinese O157:H7 outbreak strain Xuzhou21. Here we investigated the phenotypic and transcriptional differences between the wild type strain Xuzhou21 and the pO157_Sal cured mutant strain Xuzhou21m. RNA-seq analysis found that all 52 ORFs encoded on pO157_Sal were transcribed. 168 chromosomal and pO157 genes were differentially expressed (≥2 fold difference) between Xuzhou21 and Xuzhou21m. Sixty-seven and 101 genes were up-regulated and down-regulated respectively by pO157_Sal including genes related to stress response, adaption and virulence. The plasmid-cured mutant grew slower than wild type in M9 medium under the condition of high NaCl or presence of sodium deoxycholate (NaDC), corroborating with the RNA-seq data. Seven differentially expressed genes are associated with NaDC resistance, including the adenine-specific DNA-methyltransferase gene (dam), multidrug efflux system subunit gene mdtA, hyperosmotically inducible periplasmic protein gene osmY and oxidation-reduction related genes while two differentially expressed genes (osmY and pspD) are likely to be related to resistance to osmotic pressure. A number of differentially expressed genes were virulence associated including four genes encoding T3SS effectors from the chromosome and ehxD from pO157. These findings demonstrated that the plasmid pO157_Sal affects the chromosome and pO157 genes transcription and contributes to the enhanced ability to resist stress. We conclude that pO157_Sal plays an important role in regulating global gene expression and affects virulence and adaptation of E.coli O157:H7.
Project description:We report the application of next-generation sequencing (NGS) to analysis the gene expression profile among three different cells:SF-MSCs, iPSCs and iPSC-MSCs. Our results shown that iPSC-MSCs were more similar to SF-MSCs than iPSCs.
Project description:Background: Enterohemorrhagic Escherichia coli (EHEC) O157 causes severe food-bone illness in humans. The chromosome of O157 consists of 4.1-Mb backbone sequences shared by benign E. coli K-12, and 1.4-Mb O157-specific sequences encoding many virulence determinants such as Shiga toxin genes (stxs) and the locus of enterocyte effacement (LEE). Non-O157 EHECs belonging to clonal lineages distinct from O157 also cause similar illness in humans. According to the parallel evolution model, they have independently acquired the major virulence determinants, stxs and LEE. However, the genomic differences between O157 and non-O157 EHECs have not yet systematically been analyzed. Results: By using the microarray and Whole Genome PCR scanning analyses, we performed a whole genome comparison of 20 EHEC strains of O26, O111, and O103 serotypes with O157. In non-O157 EHEC strains, although genome sizes were similar with or rather larger than O157 and the backbone regions were well conserved, O157-specific regions were very poorly conserved. Only around 20% of the O157-specific genes were fully conserved in each non-O157 serotype. However, the non-O157 EHECs contained a significant number of virulence genes found on prophages and plasmids in O157, and also multiple prophages similar but significantly divergent from those in O157. Conclusion: Although O157 and non-O157 EHECs have independently acquired a huge amount of serotype- or strain-specific genes by lateral gene transfer, they share an unexpectedly large number of virulence genes. Independent infections of similar but distinct bacteriophages carrying these virulence determinants appear to be involved in the parallel evolution of EHEC. Keywords: comparative genomic hybridization, CGH
Project description:SF-1, a transcription factor belonging to the nuclear receptor superfamily, has a pivotal role for adrenogonadal development in humans and mice. A constant feature of childhood adrenocortical tumors (ACT) is SF-1 amplification and overexpression. Using an inducible cellular system, here we show that SF-1 overexpression increases human adrenocortical cell proliferation through opposing effects on cell cycle and apoptosis. SF-1 overexpression also selectively modulates steroidogenesis, reducing cortisol and aldosterone secretion. We identified a novel pro-apoptotic factor for adrenocortical cells, NOV/CCN3, whose levels are significantly reduced by SF-1 overexpression in human adrenocortical cells and are also reduced in primary adrenal tumors. Moreover, Sf-1 overexpression triggers adrenocortical hyperplasia and tumor formation in mice. These tumors express gonadal markers and activated Stat3. Our studies reveal the critical role of SF-1 gene dosage for adrenocortical tumorigenesis and constitute a rationale for the development of drugs targeting SF-1 transcriptional activity for ACT therapy. Keywords: differential expression, transcription factor
Project description:SF-1 (NR5A1) was overexpressed (Over) or knocked down with shRNA (shRNA) in NCI-H295R human adrenocortical tumor cells and differential global gene expression analysed 48 hours later using Affymetrix GeneChip Human Gene 1.0ST arrays. Over: 5 million cells were transfected (Amaxa Nucleofection) with 10 ug of a pIRES2-AcGPF1-Nuc construct co-expressing SF-1 cDNA and GFP. For experimental control, a mutagenized pIRES2 construct, bearing the G35E mutation in SF-1 that impairs its transactivation function in vivo and in vitro was used. shRNA: 5 million cells were transfected (Amaxa Nucleofection) with 10 ug of the SureSilencing shRNA Plasmid for Human NR5A1 with GFP marker kit (SABioscience). For experimental control, mismatch constructs provided in the kit were used. In both experiments (Over and shRNA), cells were harvested, prepared, and submitted to fluorescence-activated cell sorting (FACS) in a MoFlo XDP sorter 48 hours after transfection. Viable GFP-expressing cells were pooled and resuspended in TRIzol reagent for RNA extraction. Total RNA was extracted, and RNA quality control performed using a 2100 Bioanalyzer. RNA samples were processed using the Affymetrix GeneChip WT Sense Target Labeling kit, starting with 200 ng total RNA. Four independent Over experiments and five independent shRNA experiments were performed and samples of labeled fragmented cDNA were hybridized to Affymetrix GeneChip Human Gene 1.0 ST Arrays. Based on quality control of array data (R/Bioconductor and Partek Genomics Suite), two Over arrays (one SF-1 wild type and one mutant control) and one shRNA array (mismatch control) were excluded and are not deposited here. Differential gene expression analysis was performed using the limma package in R/Bioconductor. A Benjamini-Hochberg-corrected P value cut-off of 0.05 was used to select significant differentially expressed genes in each setting (Over and shRNA). Finally, results from both analyses were combined to identify a subset of positively-regulated SF-1 target genes in these cells, ie transcripts up-regulated by SF-1 overexpression (Over) and down-regulated by SF-1 knockdown (shRNA).
Project description:Escherichia coli O157:H7 is an important food-borne pathogen that can cause hemorrhagic colitis (HC) and hemolytic-uremic syndrome (HUS) in humans. pO157_Sal, a novel conjugative plasmid is present in a Chinese O157:H7 outbreak strain Xuzhou21. Here we investigated the phenotypic and transcriptional differences between the wild type strain Xuzhou21 and the pO157_Sal cured mutant strain Xuzhou21m. RNA-seq analysis found that all 52 ORFs encoded on pO157_Sal were transcribed. 168 chromosomal and pO157 genes were differentially expressed (M-bM-^IM-%2 fold difference) between Xuzhou21 and Xuzhou21m. Sixty-seven and 101 genes were up-regulated and down-regulated respectively by pO157_Sal including genes related to stress response, adaption and virulence. The plasmid-cured mutant grew slower than wild type in M9 medium under the condition of high NaCl or presence of sodium deoxycholate (NaDC), corroborating with the RNA-seq data. Seven differentially expressed genes are associated with NaDC resistance, including the adenine-specific DNA-methyltransferase gene (dam), multidrug efflux system subunit gene mdtA, hyperosmotically inducible periplasmic protein gene osmY and oxidation-reduction related genes while two differentially expressed genes (osmY and pspD) are likely to be related to resistance to osmotic pressure. A number of differentially expressed genes were virulence associated including four genes encoding T3SS effectors from the chromosome and ehxD from pO157. These findings demonstrated that the plasmid pO157_Sal affects the chromosome and pO157 genes transcription and contributes to the enhanced ability to resist stress. We conclude that pO157_Sal plays an important role in regulating global gene expression and affects virulence and adaptation of E.coli O157:H7. The total mRNA extracted from Escherichia coli O157:H7 Xuzhou21 and its plasmid cured strain Xuzhou21m were sequenced using Illumina.
Project description:SF-1 (NR5A1) was overexpressed (Over) or knocked down with shRNA (shRNA) in NCI-H295R human adrenocortical tumor cells and differential global gene expression analysed 48 hours later using Affymetrix GeneChip Human Gene 1.0ST arrays. Over: 5 million cells were transfected (Amaxa Nucleofection) with 10 ug of a pIRES2-AcGPF1-Nuc construct co-expressing SF-1 cDNA and GFP. For experimental control, a mutagenized pIRES2 construct, bearing the G35E mutation in SF-1 that impairs its transactivation function in vivo and in vitro was used. shRNA: 5 million cells were transfected (Amaxa Nucleofection) with 10 ug of the SureSilencing shRNA Plasmid for Human NR5A1 with GFP marker kit (SABioscience). For experimental control, mismatch constructs provided in the kit were used. In both experiments (Over and shRNA), cells were harvested, prepared, and submitted to fluorescence-activated cell sorting (FACS) in a MoFlo XDP sorter 48 hours after transfection. Viable GFP-expressing cells were pooled and resuspended in TRIzol reagent for RNA extraction. Total RNA was extracted, and RNA quality control performed using a 2100 Bioanalyzer. RNA samples were processed using the Affymetrix GeneChip WT Sense Target Labeling kit, starting with 200 ng total RNA. Four independent Over experiments and five independent shRNA experiments were performed and samples of labeled fragmented cDNA were hybridized to Affymetrix GeneChip Human Gene 1.0 ST Arrays. Based on quality control of array data (R/Bioconductor and Partek Genomics Suite), two Over arrays (one SF-1 wild type and one mutant control) and one shRNA array (mismatch control) were excluded and are not deposited here. Differential gene expression analysis was performed using the limma package in R/Bioconductor. A Benjamini-Hochberg-corrected P value cut-off of 0.05 was used to select significant differentially expressed genes in each setting (Over and shRNA). Finally, results from both analyses were combined to identify a subset of positively-regulated SF-1 target genes in these cells, ie transcripts up-regulated by SF-1 overexpression (Over) and down-regulated by SF-1 knockdown (shRNA). Four SF-1 overexpression experiments (Over; intervention = overexpression of wild type SF-1; control = overexpression of functionally-impaired mutant G35E SF-1) and five SF-1 knockdown experiments (shRNA; intervention = SF-1-specific small hairpin RNA; control = shRNA mismatch control) were performed in NCI-H295R cells. Differential gene expression in each setting was analysed using GeneChip Human Gene 1.0ST arrays. Data for arrays that met quality control are presented here: Over, 3 intervention and 3 control arrays; shRNA, 5 intervention and 4 control arrays. Total of 15 arrays.