The Identification of Genetic Factors Influencing Susceptibility to Staphylococcus aureus Infection in mice susceptible and resistant to S. aureus infection
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ABSTRACT:
ORGANISM(S): Mus musculus
SUBMITTER: Nicole Johnson
PROVIDER: E-GEOD-23584 | biostudies-arrayexpress |
REPOSITORIES: biostudies-arrayexpress
Similar Datasets
Project description:Although it has recently been shown that A/J mice are highly susceptible to Staphylococcus aureus sepsis as compared to C57BL/6J, the specific genes responsible for this differential phenotype are unknown. Using chromosome substitution strains (CSS), we found that factors on chromosomes (chr) 8, 11, and 18 are responsible for susceptibility to S. aureus sepsis in A/J mice. F1 mice from C57BL/6J X CSS8 cross (C8A) and C57BL/6J X CSS18 (C18A) were also susceptible to S. aureus (median survival < 48 h), whereas F1 mice from C57BL/6J X CSS11 cross (C11A) were resistant (median survival > 120 h) to S. aureus. Bacterial loads in the kidney were consistent with F1 median survivals, with higher bacterial counts in susceptible mice. No sexlinked associations with susceptibility were noted in F1 intercrosses. Using whole genome transcription profiling, we identified a total of 192 genes on chromosomes 8, 11, and 18 which are differentially expressed between A/J and C57BL/6J in the setting of S. aureus infection. Of these, 28 genes had Gene Ontology annotations indicating a potential immune response function. These 28 genes are associated with susceptibility to S. aureus in A/J mice, and are potential determinants of susceptibility to S. aureus infection in humans. To identify genes for which differential expression between A/J and C57BL/6J mice could contribute to host susceptibility to S. aureus infection, we compared the gene expression profiles between uninfected A/J and C57BL/6J mice and between infected A/J and C57BL/6J mice at 2, 4, 6, and 12 hours after infection.
2010-08-01 | E-GEOD-19668 | biostudies-arrayexpress
Project description:Defects in homocysteine and folate metabolism are associated with increased risks for neural tube and congenital heart defects, cardiovascular disease and stroke, cancers, and neurodegeneration. In many but not all cases, dietary supplementation with folate significantly reduces the severity and incidence of these conditions. Common polymorphisms modulate these metabolic pathways and disease risks, but do not fully account for the particular birth defects and adult diseases that occur in at-risk individuals. To test whether other pathways contribute to disease pathogenesis, we analyzed global and pathway-specific changes in gene expression and levels of selected metabolites after depletion and repletion of dietary folate in two genetically distinct inbred strains of mice. Compared to the C57BL/6J strain, A/J showed greater homeostatic response to folate perturbation by retaining a higher serum folate level and minimizing global gene expression changes. Remarkably, folate perturbation led to systematic strain-specific differences only in the expression profile of the cholesterol biosynthesis pathway and translated to changes in levels of serum and liver total cholesterol. By genetically increasing serum and liver total cholesterol levels in APOE deficient mice, we modestly but significantly improved folate retention during folate depletion, suggesting an interplay between homocysteine and folate metabolism and cholesterol metabolism. Absence of measurable changes in global methylation patterns or amelioration of effects with supplementation with an alternative methyl donor suggest that dietary folate perturbations do not act through large-scale or general changes in methylation. These results suggest that homeostatic responses in cholesterol metabolism contribute to the beneficial effects of dietary folate supplementation. Keywords: time course, stress response, diet, genetic, homeostasis Six-week old female C57BL/6J and B6.129P2-Apoetm1Unc/J (Piedrahita et al. 1992) mice were purchased from the Jackson Laboratory. All mice were raised on a control diet containing four ppm folic acid (Basal Diet 5755, TestDiet) for one week before the start of studies. Mice were then placed on folic acid deficient diet (58C3, TestDiet) containing 1% succinylsulfathiazole, a non-absorbable antibiotic commonly used to suppress folate production by bacteria in the intestine, for 14 days. A subset of these mice were placed back on control diet for 7 days after 14 day depletion. There were three groups of mice that underwent folic acid depletion and repletion. ApoE knockout mice on C57BL/6J background, C57BL/6J mice supplemented with 25mM choline and 50mM saccharine in drinking water, and C57BL/6J mice supplemented with 50mM saccharine. Saccharine was used to reduce the bitter taste of choline in the drinking water. We also had C57BL/6J mice on the control diet for 14 days and 21 days. These mice served as controls for treated mice from each time point during hybridization. The folate level in the control diet for this study was significantly lower than the previous study (GSE9242) due to greater loss of folic acid by irradiation of the diet. There were eight replicate mice per treatment group per folic acid perturbation protocol. An equal amount (by weight) of liver tissue from eight replicate mice was separated into two pools of four replicate tissues each. Pooled RNA from treated mice and pooled RNA from control mice for each time point were aminoallyl labeled with Cy3 and Cy5 in duplicate with reversing of dyes.
2008-08-27 | E-GEOD-9243 | biostudies-arrayexpress
Project description:This SuperSeries is composed of the following subset Series: GSE9242: Dietary folate depletion and repletion in A/J and C57BL/6J mice GSE9243: Dietary folate depletion and repletion in C57BL/6J mice, ApoE knockout mice, and choline supplemented C57BL/6J mice Keywords: SuperSeries Refer to individual Series
2010-06-20 | E-GEOD-9245 | biostudies-arrayexpress
Project description:Staphylococcus aureus causes a spectrum of human infection. Diagnostic delays and uncertainty lead to treatment delays and inappropriate antibiotic use. A growing literature suggests the hostM-bM-^@M-^Ys inflammatory response to the pathogen represents a potential tool to improve upon current diagnostics. The hypothesis of this study is that the host responds differently to S. aureus than to E. coli infection in a quantifiable way, providing a new diagnostic avenue. This study uses Bayesian sparse factor modeling and penalized binary regression to define peripheral blood gene-expression classifiers of murine and human S. aureus infection. The murine-derived classifier distinguished S. aureus infection from healthy controls and Escherichia coli-infected mice across a range of conditions (mouse and bacterial strain, time post infection) and was validated in outbred mice (AUC>0.97). A S. aureus classifier derived from a cohort of 95 human subjects distinguished S. aureus blood stream infection (BSI) from healthy subjects (AUC 0.99) and E. coli BSI (AUC 0.82). Murine and human responses to S. aureus infection share common biological pathways, allowing the murine model to classify S. aureus BSI in humans (AUC 0.84). Both murine and human S. aureus classifiers were validated in an independent human cohort (AUC 0.95 and 0.94, respectively). The approach described here lends insight into the conserved and disparate pathways utilized by mice and humans in response to these infections. Furthermore, this study advances our understanding of S. aureus infection; the host response to it; and identifies new diagnostic and therapeutic avenues. To create a host gene expression-based classifier for S. aureus infection, mice from a variety of experimental conditions were utilized. Seven different strains of inbred mice (n=187 total) were challenged with four different S. aureus strains via intraperitoneal inoculation and sacrificed at various time points as described in Methods. The comparator group for model derivation included 50 A/J or C57BL/6J mice inoculated with E. coli (O18:K1:H7) as well as 54 uninfected mice. Next, the murine S. aureus classifier was externally validated in outbred CD-1 mice with S. aureus infection (Sanger 476 or USA300), E. coli infection (O18:K1:H7), or uninfected controls (10 animals per condition). Method: All experiments were performed on mice 6-8 weeks old. For the murine S. aureus predictor, seven inbred mouse strains (3 mice/strain: 129S1/SvImJ, A/J, AKR/J, BALB/cByJ, C57BL/6J, C3H/HeJ, and NOD/LtJ) were IP inoculated with 107 CFU/g of S. aureus Sanger476, euthanized at 2h after injection, and bled. This was repeated using four different S. aureus strains (USA100, USA300, MW2, and Sanger476) in A/J mice (n=3 per S. aureus strain). For time series experiments, both A/J and C57BL/6J mouse strains were IP inoculated with S. aureus Sanger476 as above, and sacrificed at 2, 4, 6, and 12h after injection (n=5 per time point).
2013-01-11 | E-GEOD-33341 | biostudies-arrayexpress
Project description:Defects in homocysteine and folate metabolism are associated with increased risks for neural tube and congenital heart defects, cardiovascular disease and stroke, cancers, and neurodegeneration. In many but not all cases, dietary supplementation with folate significantly reduces the severity and incidence of these conditions. Common polymorphisms modulate these metabolic pathways and disease risks, but do not fully account for the particular birth defects and adult diseases that occur in at-risk individuals. To test whether other pathways contribute to disease pathogenesis, we analyzed global and pathway-specific changes in gene expression and levels of selected metabolites after depletion and repletion of dietary folate in two genetically distinct inbred strains of mice. Compared to the C57BL/6J strain, A/J showed greater homeostatic response to folate perturbation by retaining a higher serum folate level and minimizing global gene expression changes. Remarkably, folate perturbation led to systematic strain-specific differences only in the expression profile of the cholesterol biosynthesis pathway and translated to changes in levels of serum and liver total cholesterol. By genetically increasing serum and liver total cholesterol levels in APOE deficient mice, we modestly but significantly improved folate retention during folate depletion, suggesting an interplay between homocysteine and folate metabolism and cholesterol metabolism. Absence of measurable changes in global methylation patterns or amelioration of effects with supplementation with an alternative methyl donor suggest that dietary folate perturbations do not act through large-scale or general changes in methylation. These results suggest that homeostatic responses in cholesterol metabolism contribute to the beneficial effects of dietary folate supplementation. Keywords: time course, stress response, diet, genetic, homeostasis Six-week old female A/J and C57BL/6J mice were purchased from the Jackson Laboratory. All mice were raised on a control diet containing four ppm folic acid (Basal Diet 5755, TestDiet) for one week before the start of studies. Selected mice were then placed on folic acid deficient diet (58C3, TestDiet) containing 1% succinylsulfathiazole, a non-absorbable antibiotic commonly used to suppress folate production by bacteria in the intestine. We had nine different treatment plans per strain with eight replicate mice per treatment. There were four folic acid depletion treatment in which mice were placed on folic acid deficient diet for 1, 2, 7, or 14 days. There were two folic acid repletion treatment in which mice were placed on folic acid deficient diet for 14 days followed by 1 day on control diet and another set of mice on 14 days of folic acid deficient diet followed by 7 days of control diet. There were three control time points in which mice were placed on the control diet for 0, 9, or 22 days. Eight biological replicate liver tissue from each treatment was pooled and total RNA from each pool and total RNA from Universal Mouse Reference RNA (Stratagene) were aminoallyl labeled with Cy3 and Cy5 in duplicate, with reversing of dyes.
2008-08-27 | E-GEOD-9242 | biostudies-arrayexpress
Project description:The precise mechanism and effects of antibiotics in host gene expression and immunomodulation in MRSA infection is unknown. Using a well characterized Methicillin Resistant Staphylococcus aureus (MRSA) isolate USA300 in a murine model of infection, we determined that linezolid and vancomycin induced differential production of bacterial toxins and host cytokines, differences in host gene expression, and differences in immunomodulators during MRSA bloodstream infection. A total of 35 A/J mice, categorized into seven groups (no infection; no infection with linezolid; no infection with vancomycin; 2 hour post-infection (hpi) S. aureus; 24 hpi S. aureus; 24 hpi S. aureus with linezolid; and 24 hpi S. aureus with vancomycin), were used in this study. Mice were injected with USA300 (6 x 106 CFU/g via i.p. route), then intravenously treated with linezolid (25 mg/kg) or vancomycin (25 mg/kg) at 2 hpi. Control and S. aureus infected mice were euthanized at each time point (2 h or 24h) following injection. Whole blood RNA was used for microarray; three cytokines and two S. aureus toxins [PantonValentine Leukocidin (PVL) and alpha hemolysin] were quantified in mouse serum by ELISA. S. aureus CFUs were significantly reduced in blood and kidney after linezolid or vancomycin treatment in S. aureus-infected mice. In vivo IL-1M-NM-2 in mouse serum was significantly reduced in both linezolid (p=0.001) and vancomycin (p=0.006) treated mice compared to untreated ones. IL-6 was significantly reduced only in linezolid treated (p<0.001) but not in vancomycin treated mice. However, another proinflammatory cytokine, TNF-M-NM-1, did not exhibit altered levels in either linezolid or vancomycin treated mice (p=0.3 and p=0.51 respectively). In vivo level of bacterial toxin, Panton-Valentine leukocidin, in mouse serum was significantly reduced only in linezolid treated mice (p=0.02) but not in vancomycin treated mice. There was no significant effect of either treatment in in vivo level of alpha hemolysin production. Unsupervised hierarchical clustering using the gene expression data from 35 microarrays revealed distinct clustering based on infection status and treatment group. Study of the antibiotic-specific difference in gene expression identified the number of genes uniquely expressed in response to S. aureus infection, infection with linezolid treatment, and infection with vancomycin treatment. Pathway associations study for the differentially expressed genes in each comparison group (Control vs. 24 h S. aureus infection, 24 h S. aureus infection vs. 24 h S. aureus linezolid, and 24 h S. aureus infection vs. 24 h S. aureus vancomycin) in mice using Kyoto Encyclopedia of Genes and Genomes (KEGG) identified toll-like receptor signaling pathway to be common to every comparison groups studied. Glycerolipid metabolism pathway was uniquely associated only with linezolid treatment comparison group. The findings of this study provide the evidence that protein synthesis inhibitor like linezolid does a better job in treating MRSA sepsis compared to cell wall acting antibiotics like vancomycin. To identify differences in host gene expression in a murine sepsis model treated with a) linezolid and b) vancomycin, we used whole blood gene expression (RNA) signatures from A/J inbred mice infected with USA 300 MRSA to evaluate differences in host gene expression among mice treated with linezolid and vancomycin. We used 5 RNA samples from MRSA-infected, linezolid- or vancomycin-treated mice. A total of 7 experimental groups have been employed: 1) Uninfected control group: (negative controls). 2) Uninfected, linezolid-treated group: Uninfected, linezolid-treated mice. 3) Uninfected vancomycin-treated group: Uninfected, vancomycin-treated mice. 4) Infected control group (positive control 2 h) MRSA-infected, untreated mice. 5) Infected control group (positive control 24 h): MRSA-infected, untreated mice. 6) Infected linezolid group: MRSA-infected, linezolid-treated mice. 7) Infected vancomycin group: MRSA-infected, vancomycin-treated mice.
2014-06-05 | E-GEOD-38531 | biostudies-arrayexpress
Project description:Two inbred mouse strains, C57BL/6J and CAST/EiJ, were crossed to generate both initial and reciprocal F1 crosses. For each genetically distinct class of mice (F0 C57BL/6J, F0 CAST/EiJ, F1i - C57BL/6J x CAST/EiJ, F1r - CAST/EiJ x C57BL/6J, where the male parent is listed first), samples were collected from a single lobe of the liver from 6 male mice between the ages of 4 and 6 months. The 24 samples were then processed to generate strand-specific RNA-seq libraries, which were sequenced on the Illumina GAII platform using 72bp paired-end reads.
2012-09-07 | E-MTAB-1091 | biostudies-arrayexpress
Project description:Genetic variation is known to influence the amount of mRNA produced by a gene. Because molecular machines control mRNA levels of multiple genes, we expect genetic variation in components of these machines would influence multiple genes in a similar fashion. We show that this assumption is correct by using correlation of mRNA levels measured from multiple tissues in mouse strain panels to detect shared genetic influences. These correlating groups of genes (CGGs) have collective properties that on average account for 52â79% of the variability of their constituent genes and can contain genes that encode functionally related proteins. We show that the genetic influences are essentially tissue-specific and, consequently, the same genetic variations in one animal may upregulate a CGG in one tissue but downregulate the CGG in a second tissue. We further show similarly paradoxical behaviour of CGGs within the same tissues of different individuals. Thus, this class of genetic variation can result in complex inter- and intra-individual differences. This will create substantial challenges in humans, where multiple tissues are not readily available. Each sample is a single hybridisation from a given BxD strain to a C57BL/6J reference sample. Two-colour glass arrays were used. No dye swaps were employed. Data from whole brain.
2010-06-25 | E-GEOD-8355 | biostudies-arrayexpress
Project description:Genetic variation is known to influence the amount of mRNA produced by a gene. Because molecular machines control mRNA levels of multiple genes, we expect genetic variation in components of these machines would influence multiple genes in a similar fashion. We show that this assumption is correct by using correlation of mRNA levels measured from multiple tissues in mouse strain panels to detect shared genetic influences. These correlating groups of genes (CGGs) have collective properties that on average account for 52â79% of the variability of their constituent genes and can contain genes that encode functionally related proteins. We show that the genetic influences are essentially tissue-specific and, consequently, the same genetic variations in one animal may upregulate a CGG in one tissue but downregulate the CGG in a second tissue. We further show similarly paradoxical behaviour of CGGs within the same tissues of different individuals. Thus, this class of genetic variation can result in complex inter- and intra-individual differences. This will create substantial challenges in humans, where multiple tissues are not readily available. Common reference design where each hybridisation compares a single BxD strain to a common reference of C57BL/6J in the green channel. Two-colour, spotted glass arrays were used. No dye swaps were employed.
2010-06-25 | E-GEOD-8356 | biostudies-arrayexpress
Project description:DNA demethylation of paternal genome in zygotes takes place in various mammals including mice and human. Recent studies have revealed that this is achieved through Tet3-mediated iterative oxidation of 5-methylcytosine (5mC) coupled with replication-dependent dilution. Tet3-mediated paternal DNA demethylation is believed to be required for mouse development given that Tet3 heterozygous embryos, derived by fertilizing Tet3 knockout (KO) oocytes with wild-type (WT) sperms, exhibit 5mC oxidation defects and embryonic sublethality, Here we demonstrate that the sublethality phenotype of the maternal KO mice is caused by haploinsufficiency of Tet3, but not by defective paternal 5mC oxidation. We found that Tet3 heterozygous mice derived from crosses of heterozygous father or mother with WT mice also exhibit sublethality phenotype similarly to Tet3 maternal KO mice. Importantly, embryos reconstituted with WT paternal nuclei that bypassed 5mC oxidation develop to term and grow to adulthood normally. Genome-scale DNA methylation analysis of the maternal KO zygotes and blastocysts demonstrated that hypermethylation caused by the depletion of maternal Tet3 is largely diminished by the blastocyst stage. Our study thus not only demonstrates that Tet3-mediated paternal 5mC oxidation is dispensable for mouse development but also suggests the existence of a compensation mechanism in preimplantation embryos that can compensate for the defective 5mC oxidation in zygotes. This data set includes RRBS data of wild-type and maternal Tet3 KO zygotes and blastocysts (C57BL/6J x CAST/EiJ)
2015-02-28 | E-GEOD-62719 | biostudies-arrayexpress