Background. 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 SamplesStress is a powerful modulator of neuroendocrine, behavioral and immunological functions. After 4.5 days of repeated combined acoustic and restraint stress as a murine model of chronic psychological stress severe metabolic dysregulations became detectable in female BALB/c mice. Stress-induced alterations of metabolic processes that were found in a hepatic mRNA expression profiling were verified by in vivo analyses. Repeatedly stressed mice developed a hypermetabolic syndrome with severe loss of lean body mass, hyperglycemia, dyslipidemia, increased amino acid turn-over, and acidosis. This was associated with hypercortisolism, hyperleptinemia, insulin resistance, and hypothyroidism. In contrast, after a single acute stress exposure changes in expression of metabolic genes were much less pronounced and predominantly confined to gluconeogenesis, probably indicating that metabolic disturbances might be initiated already early but will only manifest in repeatedly stressed mice .Thus, in our murine model, repeated stress caused severe metabolic dysregulations leading to a drastic reduction of the individual's energy reserves. Under such circumstances stress may further reduce the ability to cope with new stressors such as infection or cancer.
Hypermetabolic syndrome as a consequence of repeated psychological stress in mice.
Sex, Age
View SamplesStress is a powerful modulator of neuroendocrine, behavioral and immunological functions. After 4.5 days of repeated combined acoustic and restraint stress as a murine model of chronic psychological stress severe metabolic dysregulations became detectable in female BALB/c mice. Stress-induced alterations of metabolic processes that were found in a hepatic mRNA expression profiling were verified by in vivo analyses. Repeatedly stressed mice developed a hypermetabolic syndrome with severe loss of lean body mass, hyperglycemia, dyslipidemia, increased amino acid turn-over, and acidosis. This was associated with hypercortisolism, hyperleptinemia, insulin resistance, and hypothyroidism. In contrast, after a single acute stress exposure changes in expression of metabolic genes were much less pronounced and predominantly confined to gluconeogenesis, probably indicating that metabolic disturbances might be initiated already early but will only manifest in repeatedly stressed mice .Thus, in our murine model, repeated stress caused severe metabolic dysregulations leading to a drastic reduction of the individual's energy reserves. Under such circumstances stress may further reduce the ability to cope with new stressors such as infection or cancer.
Hypermetabolic syndrome as a consequence of repeated psychological stress in mice.
Sex, Age
View SamplesStress is a powerful modulator of neuroendocrine, behavioral and immunological functions. After 4.5 days of repeated combined acoustic and restraint stress as a murine model of chronic psychological stress severe metabolic dysregulations became detectable in female BALB/c mice. Stress-induced alterations of metabolic processes that were found in a hepatic mRNA expression profiling were verified by in vivo analyses. Repeatedly stressed mice developed a hypermetabolic syndrome with severe loss of lean body mass, hyperglycemia, dyslipidemia, increased amino acid turn-over, and acidosis. This was associated with hypercortisolism, hyperleptinemia, insulin resistance, and hypothyroidism. In contrast, after a single acute stress exposure changes in expression of metabolic genes were much less pronounced and predominantly confined to gluconeogenesis, probably indicating that metabolic disturbances might be initiated already early but will only manifest in repeatedly stressed mice .Thus, in our murine model, repeated stress caused severe metabolic dysregulations leading to a drastic reduction of the individual's energy reserves. Under such circumstances stress may further reduce the ability to cope with new stressors such as infection or cancer.
Hypermetabolic syndrome as a consequence of repeated psychological stress in mice.
Sex, Age
View SamplesABSTRACT
Increased expression of bcl11b leads to chemoresistance accompanied by G1 accumulation.
No sample metadata fields
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 SamplesAims: Resident cardiac progenitor cells show homing properties when injected into the injured but not into the healthy myocardium. The molecular background behind this difference in behavior needs to be studied to elucidate how adult progenitor cells can restore cardiac function of the damaged myocardium. Since the brain-derived neurotrophic factor (BDNF) moderates cardioprotection in injured hearts, we focused on delineating its regulatory role in the damaged myocardium.
Brain derived neurotrophic factor contributes to the cardiogenic potential of adult resident progenitor cells in failing murine heart.
Age, Specimen part, Disease, Disease stage
View SamplesBackground: Immunoadsorption with subsequent IgG substitution (IA/IgG) represents a novel therapeutic approach in treatment of dilated cardiomyopathy (DCM) which leads to improvement of left ventricular ejection fraction (LVEF). However, response to this therapeutic intervention shows wide inter-individual variability. In this pilot study, we tested the value of clinical, biochemical and molecular parameters for prediction of the response of patients with DCM to IA/IgG.
Myocardial gene expression profiles and cardiodepressant autoantibodies predict response of patients with dilated cardiomyopathy to immunoadsorption therapy.
Sex, Age, Disease
View SamplesActivation of the immune system is a way for host tissue to defend itself against tumor growth. Hence, treatment strategies that are based on immunomodulation are on the rise. Conventional cytostatic drugs such as the anthracycline doxorubicin can also activate immune cell functions of macrophages and natural killer cells. In addition, cytotoxicity of doxorubicin can be enhanced by combining this drug with the cytokine IFN-alpha. Although doxorubicin is one of the most applied cytostatics, the molecular mechanisms of its immunomodulation ability are not investigated thoroughly. In microarray analyses of HeLa cells, a set of 19 genes related to interferon signaling was significantly overrepresented among genes regulated by doxorubicin exposure including STAT-1, -2, IRF9, NMI, and caspase 1. Regulation of these genes by doxorubicin was verified with Real-Time PCR and immunoblotting. An enhanced secretion of IFN-alpha was observed when HeLa cells were exposed to doxorubicin as compared to untreated cells. IFN-alpha neutralizing antibodies and inhibitors of JAK-STAT signaling (ATA and AG490) significantly abolished doxorubicin-stimulated expression of interferon signaling-related genes. Furthermore, inhibition of JAK-STAT signaling significantly reduced doxorubicin induced caspase 3 activation and desensitized HeLa cells to doxorubicin cytotoxicity. In conclusion, we demonstrate that doxorubicin induces interferon-responsive genes via IFN-alpha-JAK-STAT1 signaling and that this pathway is relevant for doxorubicins cytotoxicity in HeLa cells. As immunomodulation is a promising strategy in anticancer treatment, this novel mode of action of doxorubicin may help to further improve the use of this drug among different types of anticancer treatment strategies.
Regulation of interferon-inducible proteins by doxorubicin via interferon γ-Janus tyrosine kinase-signal transducer and activator of transcription signaling in tumor cells.
Cell line, Treatment
View SamplesABSTRACT
Bone marrow-derived macrophages from BALB/c and C57BL/6 mice fundamentally differ in their respiratory chain complex proteins, lysosomal enzymes and components of antioxidant stress systems.
Treatment
View Samples