Tcl1 tg mice develop a chronic lymphocytic leukemia (CLL) -like disease. To investigate the contribution of the adhesion molecule CD44 to CLL pathophysiology, we developed a CD19Cre CD44flox/flox Tcl1 tg mouse with a B cell specific CD44 deficiency (CD44B Tcl1 tg).
Microenvironment-induced CD44v6 promotes early disease progression in chronic lymphocytic leukemia.
Specimen part
View SamplesBiliary atresia (BA) is a rare cholestatic disease of unknown etiology that affects infants and shows an incidence of 1 out of 18,000 live births in Europe (1). The first therapeutic option is a timely performed portoenterostomy. However, the majority of patients suffer from a progressive inflammatory process, which leads to complete destruction of the extra- and intrahepatic biliary system followed by end-stage liver cirrhosis. Hence, BA is the leading indication for pediatric liver transplantation worldwide (2, 3). To understand the pathogenesis of the disease and improve theoutcome of BA patients, research has focused on the inflammatory process in liver and bile ducts, in which several factors are remarkably elevated, such as activated CD4 and CD8 T-cells, TNF alpha,IFN alpha and other proinflammatory TH1 cytokines (3-8). By the time of diagnosis, however, the disease has already reached an advanced state, characterized by the complete obstruction of the extrahepatic bile ducts with impaired bile flow and fibrosis or cirrhosis of the liver. Therefore, studies in humans focusing on the trigger mechanism of BA are limited due to the paucity of liver and availability of bile duct tissue for research. One infectious animal model has been developed, in which newborn Balb/c mice exclusively show the experimental BA phenotype after infection with rhesus rotavirus (RRV) (9, 10). This model allows the analysis of the inflammatory reactions in liver and bile ducts at early steps in the development of bile duct atresia (11-20). Furthermore, inbred mouse strains have been shown to have a different susceptibility for the development of experimental BA, suggesting that Balb/c mice have an immunological gap responsible for disease progression (10, 12). The aim of this study was to identify key genes responsible for the BA phenotype by comparing the transcriptomes at an early time point after virus infection, i.e. before bile duct atresia, between two mouse strains with different susceptibilities to BA. Differences in the virus titration and the clinical course of infected mice were analyzed, and variations in the hepatic gene response assessed by comparative microarray assays were correlated to variances in the hepatic inflammatory reaction.
Susceptibility to experimental biliary atresia linked to different hepatic gene expression profiles in two mouse strains.
Specimen part
View SamplesRole for naturally occurring CD4+CD25+Foxp3+ regulatory T cells (nTregs) in counterbalancing this process. Using a transgenic murine model for autoimmune-mediated lung disease, we demonstrated that, despite pulmonary inflammation, lung-specific CD8+ T cells can reside quiescently in close proximity to self-antigen. Whereas self-reactive CD8+ T cells in the inflamed lung and lung-draining lymph nodes down-regulated the expression of effector molecules, those located in the spleen appeared to be partly antigen-experienced and displayed a memory-like phenotype. Since ex vivo-reisolated self-reactive CD8+ T cells were very well capable to respond to the antigen in vitro, we investigated a possible contribution of nTregs to the immune control over autoaggressive CD8+ T cells in the lung.
CD4+CD25+Foxp3+ regulatory T cells are dispensable for controlling CD8+ T cell-mediated lung inflammation.
Specimen part
View SamplesIRAK-4 is an essential component of the signal transduction complex downstream of the IL-1- and Toll-like receptors. Though regarded as the first kinase in the signaling cascade, the role of IRAK-4 kinase activity versus its scaffold function is still controversial. In order to investigate the role of IRAK-4 kinase function in vivo, knock-in mice were generated by replacing the wild type IRAK-4 gene with a mutant gene encoding kinase deficient IRAK-4 protein (IRAK-4 KD). Analysis of bone marrow macrophages obtained from WT and IRAK-4 KD mice with a number of experimental techniques demonstrated that the IRAK-4 KD cells greatly lack responsiveness to stimulation with the Toll-like receptor 4 (TLR4) agonist LPS. One of the techniques used, microarray analysis, identified IRAK-4 kinase-dependent LPS response genes and revealed that the induction of LPS-responsive mRNAs was largely ablated in IRAK-4 KD cells. In summary, our results suggest that IRAK-4 kinase activity plays a critical role in TLR4-mediated induction of inflammatory responses.
IRAK-4 kinase activity-dependent and -independent regulation of lipopolysaccharide-inducible genes.
No sample metadata fields
View SamplesNormal human bronchial epithelial cells were studied under four different conditions: control, pressure 30 cmH2O, AG1478 (1 microM), and pressure plus AG1478 at 1, 3, and 8 hours, all in the absence of exogenous EGF.
An EGFR autocrine loop encodes a slow-reacting but dominant mode of mechanotransduction in a polarized epithelium.
Specimen part
View SamplesWe tested the hypothesis that increasing matrix stiffness on which normal human lung fibroblasts are grown promotes the expression of a fibrogenic cellular transcriptomic program.
Feedback amplification of fibrosis through matrix stiffening and COX-2 suppression.
Sex, Specimen part, Race
View SamplesThe -amyloid precursor protein APP and the related APLPs, undergo complex proteolytic processing giving rise to several fragments. Whereas it is well established that A accumulation is a central trigger for Alzheimer disease (AD), the physiological role of APP family members and their diverse proteolytic products is still largely unknown. The secreted APPs ectodomain has been shown to be involved in neuroprotection and synaptic plasticity. The -secretase generated APP intracellular domain AICD, functions as a transciptional regulator in heterologous reporter assays, although its role for endogenous gene regulation has remained controversial. To gain further insight into the molecular changes associated with knockout phenotypes and to elucidate the physiological functions of APP family members including their proposed role as transcriptional regulators we performed a DNA microarray transcriptome profiling of the frontal cortex of adult wild type, APP-/-, APLP2-/- and APPs knockin (KI) mice, APP/, expressing solely the secreted APPs ectodomain. Biological pathways affected by the lack of APP family members included regulation of neurogenesis, regulation of transcription and regulation of neuron projection development. Comparative analysis of transcriptome changes and qPCR validation identified co-regulated gene sets. Interestingly, these included heat shock proteins and plasticity related genes that were down-regulated in knock-out cortices. In contrast, we failed to detect significant differences in expression of previously proposed AICD target genes including Bace1, Kai1, Gsk3b, p53, Tip60 and Vglut2. Only Egfr was slightly up-regulated in APLP2-/- mice. Comparison of APP-/- and APP/ with wild-type mice revealed a high proportion of co-regulated genes indicating an important role of the C-terminus for cellular signaling. Finally, comparison of APLP2-/- on different genetic backgrounds revealed that background related transcriptome changes may dominate over changes due to the knockout of a single gene. Shared transcriptome profiles corroborated closely related physiological functions of APP family members in the adult central nervous system. As expression of proposed AICD target genes was not altered in adult cortex, this may indicate that these genes are not affected by lack of APP under resting conditions or only in a small subset of cells.
Comparative transcriptome profiling of amyloid precursor protein family members in the adult cortex.
Sex, Specimen part
View SamplesAutophagy is a mechanism that regulates cellular metabolism and clearance of damaged macromolecules and organelles. Impaired degradation of modified macromolecules contributes to cellular dysfunction and is observed in aged tissue and senescent cells. We have inactivated Atg7, an essential autophagy gene, in murine keratinocytes and have found in an earlier study that this resulted in increased baseline oxidative stress and reduced capacity to degrade crosslinked proteins after oxidative ultraviolet stress. To investigate whether autophagy deficiency would promote cellular aging, we studied, how Atg7 deficient (KO) and Atg7 bearing cells (WT) would respond to stress induced by Paraquat (PQ), an oxidant drug commonly used to induce cellular senescence.
Autophagy deficient keratinocytes display increased DNA damage, senescence and aberrant lipid composition after oxidative stress in vitro and in vivo.
No sample metadata fields
View SamplesEvaluation of differential expression between CLL patients in a chemoimmunotherapy trial with age-matched controls
LEF-1 is a prosurvival factor in chronic lymphocytic leukemia and is expressed in the preleukemic state of monoclonal B-cell lymphocytosis.
Specimen part, Disease, Disease stage
View SamplesIRAK-4 is an essential component of the signal transduction complex downstream of the IL-1- and Toll-like receptors. Though regarded as the first kinase in the signaling cascade, the role of IRAK-4 kinase activity versus its scaffold function is still controversial. In order to investigate the role of IRAK-4 kinase function in vivo, knock-in mice were generated by replacing the wild type IRAK-4 gene with a mutant gene encoding kinase deficient IRAK-4 protein (IRAK-4 KD). Analysis of embryonic fibroblasts and macrophages obtained from IRAK-4 KD mice with a number of experimental techniques demonstrated that they greatly lack responsiveness to stimulation with IL-1b or a Toll-like receptor 7 (TLR7) agonist. One of the techniques used, microarray analysis, identified IRAK-4 kinase-dependent IL-1b response genes in mouse embryonic fibroblasts and revealed that the induction of IL-1b-responsive mRNAs was largely ablated in IRAK-4 KD cells. In summary, our results suggest that IRAK-4 kinase activity plays a critical role in IL-1R/TLR7-mediated induction of inflammatory responses.
IRAK-4 kinase activity is required for interleukin-1 (IL-1) receptor- and toll-like receptor 7-mediated signaling and gene expression.
No sample metadata fields
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