Filters
Technology
Platform
Mus musculus
2 Downloadable Samples
Description
The cytosolic protein Sharpin is as a component of the linear ubiquitin chain assembly complex (LUBAC), which regulates NF-B signaling in response to specific ligands. Its inactivating mutation in Cpdm (chronic proliferative dermatitis mutation) mice causes multi-organ inflammation, yet this phenotype is not transferable into wildtype mice by hematopoietic stem cell transfer. Recent evidence demonstrated that Cpdm mice additionally display low bone mass, but the cellular and molecular causes of this phenotype remained to be established. Here we have applied non-decalcified histology together with cellular and dynamic histomorphometry to perform a thorough skeletal phenotyping of Cpdm mice. We show that Cpdm mice display trabecular and cortical osteopenia, solely explained by impaired bone formation, whereas osteoclastogenesis is unaffected. We additionally found that Cpdm mice display a severe disturbance of articular cartilage integrity in the absence of joint inflammation, supporting the concept that Sharpin-deficiency affects mesenchymal cell differentiation. Consistently, Cpdm mesenchymal cells displayed reduced osteogenic capacitiy ex vivo, yet this defect was not associated with impaired NF-B signaling. A molecular comparison of wildtype and Cpdm bone marrow cell populations further revealed that Cpdm mesenchymal cells produce higher levels of Cxcl5 and lower levels of IL1ra. Collectively, our data demonstrate that skeletal defects of Cpdm mice are not caused by chronic inflammation, but that Sharpin is as a critical regulator of mesenchymal cell differentiation and gene expression. They additionally provide an alternative molecular explanation for the inflammatory phenotype of Cpdm mice and the absence of disease transfer by hematopoetic stem cell transplantation.
Publication Title
Sharpin Controls Osteogenic Differentiation of Mesenchymal Bone Marrow Cells.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 16 Downloadable Samples
Description
Lactobacilli are probiotics that, among other health promoting effects, have been ascribed immunostimulating and virus preventive properties. Certain lactobacilli species have been shown to possess strong IL-12 inducing properties. As IL-12 production depends on the up-regulation of type I interferons, we hypothesized that the strong IL-12 inducing capacity of L. acidophilus NCFM in murine bone marrow derived DC is caused by an up-regulation of IFN-, which subsequently stimulates the induction of IL-12 and the dsRNA binding toll like receptor (TLR)-3. The expression of the genes encoding IFN-, IL-12, IL-10 and TLR-3 in DC upon stimulation with L. acidophilus NCFM was measured. L. acidophilus NCFM induced a much stronger expression of ifn-, il-12 and il-10 compared to the synthetic dsRNA ligand Poly I:C, whereas the levels of expressed tlr-3 were similar. By the use of whole genome microarray gene expression, we investigated whether other genes related to the viral defence were up-regulated in DC upon stimulation with L. acidophilus NCFM and found that various virus defence related genes, both early and late, were among the strongest up-regulated genes. The IFN- stimulating capability was also detected in another L. acidophilus strain, but was not a property of other probiotic bacteria tested (B. bifidum and E. coli nissle).The IFN- inducing capacity was markedly reduced in TLR-2 -/- DCs, dependent on endocytosis and the major cause of the induction of il-12 and tlr-3 in L. acidophilus NCFM stimulated cells. Collectively, our results reveal that certain lactobacilli trigger the expression of viral defence genes in DC in a TLR-2 manner through induction of IFN- .
Publication Title
Lactobacillus acidophilus induces virus immune defence genes in murine dendritic cells by a Toll-like receptor-2-dependent mechanism.
Sample Metadata Fields
Treatment, Time
View Samples
GSE2843- Mus musculus
- 3 Downloadable Samples
Description
Glucocorticoids (GC) are in most chemotherapy protocols for lymphoid malignancies, particularly childhood acute lymphoblastic leukaemia (ALL) for their ability to induce apoptosis in malignant blast. The underlying mechanism, however, has so far only been investigated in model systems. This study comprises Affymetrix hgu133 plus 2.0 analyses of
Publication Title
Identification of glucocorticoid-response genes in children with acute lymphoblastic leukemia.
Sample Metadata Fields
No sample metadata fields
View Samples- Mus musculus, Homo sapiens
- 66 Downloadable Samples
Description
Neurofibromatosis Type 1 (NF1) patients develop benign neurofibromas and malignant peripheral nerve sheath tumors (MPNST). These incurable peripheral nerve tumors result from loss of NF1 tumor suppressor gene function, causing hyperactive Ras signaling. Activated Ras controls numerous downstream effectors, but specific pathways mediating effects of hyperactive Ras in NF1 tumors are unknown. Cross-species transcriptome analyses of mouse and human neurofibromas and MPNSTs identified global negative feedback of genes that regulate Ras-Raf- MEK- extracellular signal-regulated protein kinase (ERK) signaling in both species. Nonetheless, activation of ERK was sustained in mouse and human neurofibromas and MPNST. PD0325901, a highly selective pharmacological inhibitor of MEK, was used to test whether sustained Ras-Raf-MEK-ERK signaling contributes to neurofibroma growth in the Nf1fl/fl;Dhh-cre mouse model or in NF1 patient MPNST cell xenografts. PD0325901 treatment reduced aberrantly proliferating cells in neurofibroma and MPNST, prolonged survival of mice implanted with human MPNST cells, and shrank neurofibromas in >80% of mice tested. PD0325901 also caused effects on tumor vasculature. Our data demonstrate that deregulated Ras/ERK signaling is critical for the growth of NF1 peripheral nerve tumors and provide strong rationale for testing MEK inhibitors in NF1 clinical trials.
Publication Title
MEK inhibition exhibits efficacy in human and mouse neurofibromatosis tumors.
Sample Metadata Fields
Specimen part
View Samples