Genetic diversity of a single Helicobacter pylori strain over a ten year period in a primate model: effect of long term colonization and of a dietary carcinogen
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ABSTRACT:
ORGANISM(S): Helicobacter pylori
SUBMITTER: Nina Salama
PROVIDER: E-GEOD-60474 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
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Project description:The monkey infecting Helicobacter pylori strain USU101 used in a long term infection of macaques with and without the dietary carcinogen ENNG was analyzed for gene content compared to the sequenced strains 26695 and J99 We performed array CGH using two microarrays to analyze the gene content of the starting strain (USU101) used for the monkey infection experiment (GSE60405). The ENNG information is not relevant.
2014-08-18 | E-GEOD-60404 | biostudies-arrayexpress
Project description:Helicobacter pylori strains USU101 was infected into macaques, some of which were treated with the dietary carcinogen ENNG. After 5 years, H. pylori isolates were obtained by endoscopy followed by culture. The resulting strains were analyzed for differences in gene content by array CGH. Array CGH was performed by two color microarray. The monkey output strains were labeled with Cy5 (channel 2) and the input strain USU101 was labeled with Cy3 (channel 1). Each output strain was analyzed by 2-3 separate array experiments.
2014-08-18 | E-GEOD-60405 | biostudies-arrayexpress
Project description:Resistance to agricultural fungicides in the field has created a need for discovering fungicides with new modes of action. DNA microarrays, because they provide information on expression of many genes simultaneously, could help to identify the modes of action. To begin an expression pattern database for agricultural fungicides, transcriptional patterns of Saccharomyces cerevisiae strain S288C genes were analysed following 2-h treatments with I50 concentrations of ergosterol biosynthesis inhibitors commonly used against plant pathogenic fungi. Eight fungicides, representing three classes of ergosterol biosynthesis inhibitors, were tested. To compare gene expression in response to a fungicide with a completely different mode of action, a putative methionine biosynthesis inhibitor (MBI) was also tested. Expression patterns of ergosterol biosynthetic genes supported the roles of Class I and Class II inhibitors in affecting ergosterol biosynthesis, confirmed that the putative MBI did not affect ergosterol biosynthesis, and strongly suggested that in yeast, the Class III inhibitor did not affect ergosterol biosynthesis. The MBI affected transcription of three genes involved in methionine metabolism, whereas there were essentially no effects of ergosterol synthesis inhibitors on methionine metabolism genes. There were no consistent patterns in other up- or downregulated genes between fungicides. These results suggest that inspection of gene response patterns within a given pathway may serve as a useful first step in identifying possible modes of action of fungicides. agricultural sterol biosynthesis inhibitor fungicides. Keywords = agriculture Keywords = ergosterol Keywords = methionine Keywords = fungicide Keywords = Saccharomyces cerevisiae S288C Keywords = biosynthesis
2010-06-10 | E-GEOD-2412 | biostudies-arrayexpress
Project description:Perfluorooctanoic acid (PFOA) is a potent hepatocarcinogen and peroxisome proliferator (PP) in rodents. Humans are not susceptible to peroxisome proliferation and are thought to be refractory to carcinogenesis by PFOA and other PPs. However, previous studies with rainbow trout have shown that they are also insensitive to peroxisome proliferation by the PP, dehydroepiandrosterone (DHEA), but are still susceptible to enhanced hepatocarcinogenesis after chronic exposure. In this study, we determined whether PFOA is also a tumor promotor in trout and then examined hepatic gene expression profiles to further investigate possible mechanisms of action. Trout were initiated as fry to the hepatocarcinogen, aflatoxin B1, and then fed 200-1800 ppm PFOA in the diet for 30 weeks. Two structurally diverse PPs, clofibrate (CLOF) and DHEA, were included for comparison. Hepatic gene expression profiles were subsequently examined in animals exposed to similar doses of PFOA, DHEA and CLOF along with 5 ppm 17β-estradiol (E2; a known tumor promotor) in the diet. PFOA (1800 ppm) and DHEA treatments resulted in enhanced liver tumor incidence and multiplicity while CLOF showed no effect. Carcinogenesis seemed independent of peroxisome proliferation as no induction of peroxisomal β-oxidation and catalase activity were observed. Alternately, plasma VTG was elevated in fish fed PFOA and DHEA suggesting that estrogenic mechanisms may play a role. Both tumor promotors, PFOA and DHEA, resulted in strong correlation of transcriptional profiles with E2 by Pearson correlation (R=0.81 and 0.78, respectively). In comparison, CLOF regulated no genes in common with E2. Overall, these data suggest that the tumor promoting activities of DHEA and PFOA in trout are independent of peroxisome proliferation and may involve estrogenic mechanisms. Juvenile trout, 12-18 months old, were fed experimental diets containing 500 or 1800 ppm PFOA, 1800 ppm CLOF, 750 ppm DHEA, 5 ppm E2 or 0.15 % dimethyl sulfoxide vehicle control for 14 days. Liver samples were collected for microarray analysis. Hybridizations were performed using standard reference design with dye-swapping. For each sample, equal amounts of RNA (µg) were pooled from five fish per tank for every treatment (n=3 biological replicates per treatment). cDNA from two of the three biological replicates was dye-swapped and hybridized to two slides as technical replicates (5 arrays per treatment).
2007-08-31 | E-GEOD-7837 | biostudies-arrayexpress
Project description:Although immune mechanisms have been described for Peyer’s patch function, in discriminating food nutrients and commensal microflora from pathogenic challenge, an understanding of gene expression patterns associated with normal intestinal homeostasis is lacking. The effects of commensal bacterial colonization on global gene expression in the small intestine of germ-free mice have been described (1, 2). However, no studies have compared expression patterns of various healthy lymphoid tissues in conventionally-raised pigs or other species. The objective of this study was to investigate the pattern of normal gene expression in jejunal Peyer’s patches (JPP) of healthy pigs. We hypothesized that gene expression of intact jejunal Peyer's patch is characterized by genes associated with absorption and secretory functions as well as genes associated with GALT-specific immune functions. Eight hybridizations were performed, with dye swaps of JPP mRNA from four juvenile pigs. Each hybridization compared JPP from an individual pig to the jejunal mesenteric lymph node reference sample, which was pooled from all juvenile pigs in the study. However, two of the hybridizations resulted in poor quality data, and were excluded from further analysis. Normalization, hierarchical clustering, data visualization, and statistical analysis were performed by GeneSpring version 6.2 (Silicon Genetics, Redwood, CA). GeneSpring standardized the intensities for each spot by subtracting the local background, and then normalized globally by locally weighted linear regression (Lowess). A Lowess curve was fit to the log-intensity versus log-ratio plot. 20.0% of the data was used to calculate the Lowess fit at each point. This curve was used to adjust the control value for each measurement. If the control channel was lower than 10 then 10 was used instead. Spots with a flag value of “0” were excluded. The intensity of negative control DNA-containing spots was used to additionally exclude low intensity data. Negative controls include the gene for Arabidopsis thaliana homeodomain-like protein (AY054571); 200 ng/microl Poly(dA) (Amersham, Piscataway, NJ); a 461 bp fragment of the kanamycin-resistant gene, amplified from the pET24b+ plasmid (Novagen, Madison, WI); PRRS virus strain VR-2332 (PRU87392) ORFs 2, 3, 4, 5, 6 and 7; pCMVSport 6 plasmid (Invitrogen, Carlsbad, CA); and pGEM-T plasmid (Promega, Madison WI). The mean intensity of the negative controls for both Cy3 and Cy5 was calculated for each slide, and spots with a mean intensity less than the mean intensity + 2SD were excluded from further analysis. After normalization, GeneSpring averaged replicate spots for each clone across hybridizations. GeneSpring used the Cross Gene Error Model, which was based on replicate values. A Student’s t-test with the Benjamini and Hochberg false discovery rate multiple testing correction (MTC) verified the difference between the natural log of the normalized gene expression ratio (JPP:j-MLN) and a ratio of 1.0. p-values less than 0.05 were considered significant. Series_references: 1.Fukushima K, Ogawa H, Takahashi K, Naito H, Funayama Y, Kitayama T, Yonezawa H, and Sasaki I. Non-pathogenic bacteria modulate colonic epithelial gene expression in germ-free mice. Scand J Gastroenterol 38: 626-634, 2003. 2. Hooper LV, Wong MH, Thelin A, Hansson L, Falk PG, and Gordon JI. Molecular analysis of commensal host-microbial relationships in the intestine. Science 291: 881-884, 2001.
2004-11-04 | E-GEOD-1913 | biostudies-arrayexpress
Project description:RNA from all normal tissues were pooled in equal amounts and used to create the normal tissue library. RNA from all immune stimulated tissues (Salmonella infection, CT+LPS, and PBC, with and without cycloheximide) were pooled in equal amounts and used to create the immune stimulated tissue library. The subtracted library was created by combining the normal and immune stimulated libraries and by subtracting porcine fibroblast RNA.
2010-06-05 | E-GEOD-1970 | biostudies-arrayexpress
Project description:Comparison of plants that overexpress PK12 and non-transformed plants. Plants were grown for 10 days under long day conditions (GSM3816-GSM3819) or plants were grown for 21 days under long day conditions (GSM3820-GSM3823) . Hybridization was performed on arrays from Arabidopsis Keck Resource Lab Array (Yale University) containing 12K (GSM3816-GSM3819) or 9K (GSM3820-GSM3823)Arabidopsis ESTs. The 4 samples corresponding to each array represent 2 repetitions of 2 independent biological experiments. Keywords = Alternative splicing Keywords = phosphorylation
2003-02-04 | E-GEOD-274 | biostudies-arrayexpress
Project description:Profiles of gene expression in hepatopancreas isolated from shrimp experimentally infected with White Spot Syndrome Virus were compared to those of un-infected controls Keywords: response to viral disease Two groups of eight shrimp were compared in terms of hepatopancreas gene expression, 40 hours after challenge with White Spot Syndrome Virus
2010-07-01 | E-GEOD-4955 | biostudies-arrayexpress
Project description:Experiment designed to identify differences in gene expression profile in white adipose tissue upon stimulation by beta 3 adrenergic receptor agonist. This series compares 2 groups of C57BL/6J acutely treated with CL-316,243 or Saline for 3 hours.
2010-06-11 | E-GEOD-2674 | biostudies-arrayexpress
Project description:Effect of human macrophages phagocytosis on the global transcriptome of EDL933 at different time. Infection of THP-1 with EDL933. Application of SCOTS technique to have cDNA. Hybridation on microarray. Reference: EDL933 in RPMI medium Keywords: stres response, host-bacteria response, time-course For each time point, 2 microarray are analysed and on each microarray there is 2 replicate Total of 4 replicate for each time point (including reference medium)
2010-06-24 | E-GEOD-9671 | biostudies-arrayexpress