Analysis of hematopoietic stem cells (HSC, LSK Flt3-) and myeloid progenitors (MP, LK CD34+) sorted from wildtype and Dnmt1 hypomorph mice
DNA methylation protects hematopoietic stem cell multipotency from myeloerythroid restriction.
Specimen part
View SamplesBackground. Infections caused by Staphylococcus aureus are associated with significant morbidity and mortality and are an increasing threat not only in hospital settings. The expression of the staphylococcal virulence factor repertoire is known to be affected by the alternative sigma factor B (SigB). However, its impact during infection still is a matter of debate. Methods. Kidney tissue of controls or mice infected with S. aureus HG001 or its isogenic sigB mutant was analyzed by transcriptome profiling to monitor the host response, and additionally expression of selected S. aureus genes was monitored by RT-qPCR. Results. Direct transcript analysis by RT-qPCR revealed significant SigB activity in all mice infected with the wild type strain (WT), but not in its isogenic sigB mutant (p<0.0001). Despite a clear cut difference in the SigB-dependent transcription pattern of virulence genes (clfA, aur, and hla), the host reaction to infection (either WT or sigB mutant) was almost identical. Conclusions. Despite its significant activity in vivo, loss of SigB did not have an effect on the outcome of infection as well as on murine kidney gene expression pattern. Thus, these data support the role of SigB as virulence modulator rather than being a virulence determinant by itself.
The alternative sigma factor B modulates virulence gene expression in a murine Staphylococcus aureus infection model but does not influence kidney gene expression pattern of the host.
Sex, Specimen part
View SamplesThe species Staphylococcus (S.) aureus harbors 19 superantigen gene loci, six of which are located in the enterotoxin gene cluster (egc). While these egc superantigens are far more prevalent in clinical S. aureus isolates than non-egc superantigens, they are not a prominent cause of toxic shock. Moreover, neutralizing antibodies against egc superantigens are very rare, even among carriers of egc-positive S. aureus strains. In search of an explanation we have tested two non-exclusive hypotheses: 1) egc and non-egc superantigens have unique intrinsic properties and drive the immune system into different directions; 2) egc and non-egc-superantigens are released by S. aureus under different conditions, which shape the immune response.
Immune cell activation by enterotoxin gene cluster (egc)-encoded and non-egc superantigens from Staphylococcus aureus.
No sample metadata fields
View SamplesThe contribution of altered posttranscriptional gene silencing (PTGS) to the development of insulin resistance and type 2 diabetes mellitus so far remains elusive. We have described that expression of microRNAs (miR)-143 and -145 is dysregulated in genetic and dietary mouse models of obesity. Induced transgenic overexpression of miR-143, but not miR-145, causes insulin resistance and impaired insulin-stimulated AKT activation. We used microarrays to analyze the underlying molecular mechanisms of miR-143-mediated development of insulin resistance.
Obesity-induced overexpression of miRNA-143 inhibits insulin-stimulated AKT activation and impairs glucose metabolism.
Specimen part, Treatment
View SamplesIL-6 induces IL4ralpha expression in macrophages. This mechanism is necessary to promote macrophage polarization towards an M2-phenotype and is crucial to limit the inflammatory response both upon obesity and LPS-endotoxemia.
Signaling by IL-6 promotes alternative activation of macrophages to limit endotoxemia and obesity-associated resistance to insulin.
Specimen part
View SamplesOlfaction is fundamental for survival but there is little known about the connection between smell perception and metabolism. In this study we implemented IGF1R knockout mice in the olfactory sensory neurons, by olfactory marker protetin (OMP) Cre specific recombination, and investigated metabolic parameters, smell perception and transcriptome sequencing. We could demonstrate that IGF1R knockout in the olfactory sensory neurons results in enhanced smell perception, insulin resistance under normal chow diet conditions and increased adiposity in mice fed control diet. Transcriptome analysis of the olfactory epithelium revealed differential expression of markers for mature and immature olfactory sensory neurons, being down-regulated and up- regulated respectively, pointing to differentiation-dependent changes that result in increased olfactory perception. Collectively, this study provides evidence that enhanced smell perception can result in insulin resistance and increased adiposity. Overall design: mRNA profiles of olfactory sensory neurons (OSN) extracted from homozygous tissue-specific IGF1R knockout (OMPIGF1R) and respective cotnrol mice (OMPflfl) were generated by deep sequencing, in four replicates using Illumina sequencing
The Sense of Smell Impacts Metabolic Health and Obesity.
Age, Cell line, Subject
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