664 research outputs found
Daptomycin versus Friulimicin B: In-Depth Profiling of Bacillus subtilis Cell Envelope Stress Responses
No full textThe related lipo(depsi)peptide antibiotics daptomycin and friulimicin B show great potential in the treatment of multiply resistant gram-positive pathogens. Applying genome-wide in-depth expression profiling, we compared the respective stress responses of Bacillus subtilis. Both antibiotics target envelope integrity, based on the strong induction of extracytoplasmic function sigma factor-dependent gene expression. The cell envelope stress-sensing two-component system LiaRS is exclusively and strongly induced by daptomycin, indicative of different mechanisms of action in the two compounds
Extensive alterations of the whole-blood transcriptome are associated with body mass index: results of an mRNA profiling study involving two large population-based cohorts
No full textB cells acquire a unique and differential transcriptomic profile during pregnancy
No full textPregnancy alters B cell development and function. B cell activation is initiated by antigens binding to the BCR leading to B cell survival, proliferation, antigen presentation and antibody production. We performed a genome-wide transcriptome profiling of splenic B cells from pregnant (P) and non-pregnant (NP) mice and identified 1136 genes exhibiting differential expression in B cells from P mice (625 up- and 511 down-regulated) compared to NP animals. In silico analysis showed that B cell activation through BCR seems to be lowered during pregnancy. RT-qPCR analysis confirmed these data. Additionally, B cells from pregnant women stimulated in vitro through BCR produced lower levels of inflammatory cytokines compared to non-pregnant women. Our results suggest that B cells acquire a state of hypo-responsiveness during gestation, probably as part of the maternal immune strategy for fetal tolerance but also open new avenues to understand why pregnant women are at highest risk for infections.Fil: Valeff, Natalin Jimena. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Muzzio, Damián Oscar. Greifswald University; AlemaniaFil: Matzner, Franziska. Greifswald University; AlemaniaFil: Dibo, Marcos Javier. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; ArgentinaFil: Golchert, Janine. University Medicine Greifswald; AlemaniaFil: Homuth, Georg. University Medicine Greifswald; AlemaniaFil: Abba, Martín Carlos. Consejo Nacional de Investigaciones Científicas y Técnicas; Argentina. Universidad Nacional de La Plata. Facultad de Ciencias Médicas. Centro de Investigaciones Inmunológicas Básicas y Aplicadas; ArgentinaFil: Zygmunt, Marek. Greifswald University; AlemaniaFil: Jensen, Cristian Federico. Consejo Nacional de Investigaciones Científicas y Técnicas. Oficina de Coordinación Administrativa Houssay. Centro de Estudios Farmacológicos y Botánicos. Universidad de Buenos Aires. Facultad de Medicina. Centro de Estudios Farmacológicos y Botánicos; Argentina. Universidad Bernardo O'Higgins; Chil
Angiotensin II induces soluble fms-Like tyrosine kinase-1 release via calcineurin signaling pathway in pregnancy
No full textMaternal endothelial dysfunction in preeclampsia is associated with increased soluble fms-like tyrosine kinase-1 (sFlt-1), a circulating antagonist of vascular endothelial growth factor and placental growth factor. Angiotensin II (Ang II) is a potent vasoconstrictor that increases concomitant with sFlt-1 during pregnancy. Therefore, we speculated that Ang II may promote the expression of sFlt-1 in pregnancy. Here we report that infusion of Ang II significantly increases circulating levels of sFlt-1 in pregnant mice, thereby demonstrating that Ang II is a regulator of sFlt-1 secretion in vivo. Furthermore, Ang II stimulated sFlt-1 production in a dose- and time-dependent manner from human villous explants and cultured trophoblasts but not from endothelial cells, suggesting that trophoblasts are the primary source of sFlt-1 during pregnancy. As expected, Ang II-induced sFlt-1 secretion resulted in the inhibition of endothelial cell migration and in vitro tube formation. In vitro and in vivo studies with losartan, small interfering RNA specific for calcineurin and FK506 demonstrated that Ang II-mediated sFlt-1 release was via Ang II type 1 receptor activation and calcineurin signaling, respectively. These findings reveal a previously unrecognized regulatory role for Ang II on sFlt-1 expression in murine and human pregnancy and suggest that elevated sFlt-1 levels in preeclampsia may be caused by a dysregulation of the local renin/angiotensin system
In-Depth Profiling of the LiaR Response of Bacillus subtilis†
No full textThe Lia system, a cell envelope stress response module of Bacillus subtilis, is comprised of the LiaRS two-component system and a membrane-anchored inhibitor protein, LiaF. It is highly conserved in the Firmicutes bacteria, and all orthologs investigated so far are activated by cell wall antibiotics. In response to envelope stress, the systems in Firmicutes cocci induce the expression of a number of genes that are involved in conferring resistance against its inducers. In contrast, a complete picture of the LiaR regulon of B. subtilis is still missing and no phenotypes could be associated with mutants lacking LiaRS. Here, we performed genome-wide transcriptomic, proteomic, and in-depth phenotypic profiling of constitutive “Lia ON ” and “Lia OFF ” mutants to obtain a comprehensive picture of the Lia response of Bacillus subtilis. In addition to the known targets liaIH and yhcYZ-yhdA, we identified ydhE as a novel gene affected by LiaR-dependent regulation. The results of detailed follow-up gene expression studies, together with proteomic analysis, demonstrate that the liaIH operon represents the only relevant LiaR target locus in vivo. It encodes a small membrane protein (LiaI) and a phage shock protein homolog (LiaH). LiaH forms large oligomeric rings reminiscent of those described for Escherichia coli PspA or Arabidopsis thaliana Vipp1. The results of comprehensive phenotype studies demonstrated that the gene products of the liaI
The inverse link between genetic risk for schizophrenia and migraine through NMDA (N-methyl-D-aspartate) receptor activation via D-serine
No full textSchizophrenia has a considerable genetic background. Epidemiological studies suggest an inverse clinical association between schizophrenia and migraine. However, it is unclear to what extent this inverse comorbidity can be explained by genetic mechanisms or by schizophrenia-related behavioral factors. For both disorders hypotheses of glutamate N-methyl-D-aspartate (NMDA) receptor dysfunction have been developed in the past. We hypothesized that both conditions share common genetic factors with inverse effects, primary in the glutamatergic system and genes involved in NMDA activation. Data from the population based Study of Health in Pomerania (N=3973) were used. Based on the results from the recent genome-wide association study for schizophrenia, we calculated polygenic scores (PRS) for subsets of SNPs with different p-value cutoffs and for biological sub entities. These scores were tested for an association of distinct biological pathways with migraine. The PRS for schizophrenia was inversely associated with migraine in our sample. This association was exclusively based on the genome-wide hits and on single nucleotide polymorphisms near or within genes encoding proteins involved in glutamatergic neurotransmission. This association could be attributed to a single intronic variant rs4523957 in SRR encoding serine-racemase. Additional expression quantitative trait loci analyses of functional variants in SRR and gene-by gene interaction analyses further supported the validity of this finding. SRR represents the rate limiting enzyme for the synthesis of D-serine, an important co-agonist of the NMDA receptor. According to our results, a decreased versus increased activation of NMDA receptors may play a role in the etiology of schizophrenia, as well as in migraine. (C) 2016 Elsevier B.V. and ECNP. All rights reserved
Genome-wide gene-environment interaction in depression: a systematic evaluation of candidate genes: the childhood trauma working-group of PGC-MDD
No full textGene by environment (GxE) interaction studies have investigated the influence of a number of candidate genes and variants for major depressive disorder (MDD) on the association between childhood trauma and MDD. Most of these studies are hypothesis driven and investigate only a limited number of SNPs in relevant pathways using differing methodological approaches. Here (1) we identified 27 genes and 268 SNPs previously associated with MDD or with GxE interaction in MDD and (2) analyzed their impact on GxE in MDD using a common approach in 3944 subjects of European ancestry from the Psychiatric Genomics Consortium who had completed the Childhood Trauma Questionnaire. (3) We subsequently used the genome-wide SNP data for a genome-wide case-control GxE model and GxE case-only analyses testing for an enrichment of associated SNPs. No genome-wide significant hits and no consistency among the signals of the different analytic approaches could be observed. This is the largest study for systematic GxE interaction analysis in MDD in subjects of European ancestry to date. Most of the known candidate genes/variants could not be supported. Thus, their impact on GxE interaction in MDD may be questionable. Our results underscore the need for larger samples, more extensive assessment of environmental exposures, and greater efforts to investigate new methodological approaches in GxE models for MDD.Sandra Van der Auwera, Wouter J. Peyrot, Yuri Milaneschi, Johannes Hertel, Bernhard Baune, Gerome Breen, Enda Byrne, Erin C. Dunn, Helen Fisher, Georg Homuth, Douglas Levinson, Cathryn Lewis, Natalie Mills, Niamh Mullins, Matthias Nauck, Giorgio Pistis, Martin Preisig, Marcella Rietschel, Stephan Ripke, Patrick Sullivan, Alexander Teumer, Henry Völzke, Major Depressive Disorder Working Group of the Psychiatric Genomics Consortium, Dorret I. Boomsma, Naomi R. Wray, Brenda Penninx, Hans Grab
Transcriptional Analysis of Major Heat Shock Genes of <i>Helicobacter pylori</i>
No full textABSTRACT
The transcriptional organization and heat inducibility of the major heat shock genes
hrcA
,
dnaK
,
dnaJ
,
groEL
, and
htpG
were analyzed on the transcriptional level in
Helicobacter pylori
strain 69A. The strongly heat-induced
dnaK
operon was found to be tricistronic, consisting of the genes
hrcA
,
grpE
, and
dnaK
. The
dnaJ
gene specified one monocistronic mRNA which was also heat inducible. The genes
groES
and
groEL
were transcribed as one strongly heat-inducible bicistronic mRNA which exhibited exactly the same induction kinetic as the
dnaK
operon. Surprisingly, transcription of the monocistronic
htpG
gene was switched off after heat shock. The data presented are discussed with regard to the different mechanisms regulating expression of heat shock genes in
H. pylori
</jats:p
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