Project description:In the present study, genomic binding sites of glucocorticoid receptors (GR) were identified in vivo in the rat hippocampus applying chromatin immunoprecipitation followed by next-generation sequencing. We identified 2470 significant GR-binding sites (GBS) and were able to confirm GR binding to a random selection of these GBS covering a wide range of P values. Analysis of the genomic distribution of the significant GBS revealed a high prevalence of intragenic GBS. Gene ontology clusters involved in neuronal plasticity and other essential neuronal processes were overrepresented among the genes harboring a GBS or located in the vicinity of a GBS. Male adrenalectomized rats were challenged with increasing doses of the GR agonist corticosterone (CORT) ranging from 3 to 3000 μg/kg, resulting in clear differences in the GR-binding profile to individual GBS. Two groups of GBS could be distinguished: a low-CORT group that displayed GR binding across the full range of CORT concentrations, and a second high-CORT group that displayed significant GR binding only after administering the highest concentration of CORT. All validated GBS, in both the low-CORT and high-CORT groups, displayed mineralocorticoid receptor binding, which remained relatively constant from 30 μg/kg CORT upward. Motif analysis revealed that almost all GBS contained a glucocorticoid response element resembling the consensus motif in literature. In addition, motifs corresponding with new potential GR-interacting proteins were identified, such as zinc finger and BTB domain containing 3 (Zbtb3) and CUP (CG11181 gene product from transcript CG11181-RB), which may be involved in GR-dependent transactivation and transrepression, respectively. In conclusion, our results highlight the existence of 2 populations of GBS in the rat hippocampal genome. - See more at: http://press.endocrine.org/doi/10.1210/en.2012-2187?url_ver=Z39.88-2003&rfr_id=ori:rid:crossref.org&rfr_dat=cr_pub%3dpubmed#sthash.LqK088DP.dpuf
2016-07-09 | GSE84202 | GEO
Project description:Resequencing data of 120 rice RILs
Project description:The CiaRH and LiaFSR two-component regulatory systems in Streptococcus agalactiae (Group B Streptococcus, GBS) are essential mediators of the organism s response to biologically important sources of environmental stress, and positive regulators of GBS virulence. Transcriptional profiling of CiaR mutant GBS and LiaR mutant GBS reveals that LiaR is positively-regulated by CiaR, and the individual mutant transcriptomes share a number of commonly-regulated genes. To determine the GBS response to loss of both of these key regulatory systems, we constructed a GBS mutant strain with non-polar deletions in both ciaR and liaR, and performed transcriptional profiling using DNA microarray analysis, comparing wild-type GBS to CiaR/LiaR double mutant GBS under non-stressed conditions.
Project description:Group B Streptococcus (GBS) is a pervasive perinatal pathogen, yet factors driving GBS dissemination in utero are poorly defined. Gestational diabetes mellitus (GDM), a complication marked by dysregulated immunity and maternal microbial dysbiosis, increases risk for GBS perinatal disease. We interrogated host-pathogen dynamics in a novel murine GDM model of GBS colonization and perinatal transmission. GDM mice had greater GBS in utero dissemination and subsequently worse neonatal outcomes. Dual-RNA sequencing revealed differential GBS adaptation to the GDM reproductive tract, including a putative glycosyltransferase (yfhO), and altered host responses. GDM disruption of immunity included reduced uterine natural killer cell activation, impaired recruitment to placentae, and altered vaginal cytokines. Lastly, we observed distinct vaginal microbial taxa associated with GDM status and GBS invasive disease status. Our translational model of GBS perinatal transmission in GDM hosts recapitulates several clinical aspects and enables discovery of host and bacterial drivers of GBS perinatal disease.
Project description:CsrRS is a two-component regulatory system that controls expression of multiple genes and affects virulence in group B Streptococcus (GBS), a major cause of neonatal sepsis and of invasive infection in chronically ill adults. To better understand the CsrRS regulon and its importance in GBS pathogenicity, we used GBS genomic microarrays to compare global gene expression in GBS strains 2603V/R and 515 with that in CsrR or CsrS isogenic mutants. These results and comparison with data reported previously for GBS strain NEM316 demonstrated a conserved CsrRS regulon of approximately 30 genes including those encoding beta-hemolysin, CAMP factor, and C5a-peptidase, as well as a variable repertoire of genes regulated in one or two of the three strains. Inactivation of CsrS had a similar but weaker effect at most regulated loci, but, in some cases, resulted in more pronounced or divergent regulation compared to CsrR. We conclude that CsrRS regulates a core group of genes including important virulence factors in diverse strains of GBS, but also displays marked variability in the repertoire of regulated genes and in the relative effects of CsrS signaling on CsrR-mediated gene regulation. Such variation is likely to play an important role in strain-specific adaptation of GBS to particular host environments and pathogenic potential in susceptible hosts.