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GSE14361
Mus musculus
5 Downloadable Samples
Description
Maintenance of the blood system is dependent on dormant haematopoietic stem cells (HSCs) with long-term self-renewal capacity. Upon injury these cells are induced to proliferate in order to quickly re-establish homeostasis. The signalling molecules promoting the exit of HSCs out of the dormant stage remain largely unknown. Here we show that in response to treatment of mice with interferon-alpha (IFN), HSCs efficiently exit G0 and enter an active cell cycle. HSCs respond to IFN treatment by increased phosphorylation of STAT1 and PKB/Akt, expression of IFN target genes and up-regulation of stem cell antigen-1 (Sca-1). HSCs lacking either the interferon-/ receptor (IFNAR), STAT1 or Sca-1 are insensitive to IFN stimulation, demonstrating that STAT1 and Sca-1 mediate IFN induced HSC proliferation. Although dormant HSCs are resistant to the anti-proliferative chemotherapeutic agent 5-FU1, HSCs pre-treated (primed) with IFN and thus induced to proliferate are efficiently eliminated by 5-FU exposure in vivo. Conversely, HSCs chronically activated by IFN are functionally compromised and are rapidly out competed by non-activatable IFNAR-/- cells in competitive repopulation assays. In summary, while chronic activation of the IFN pathway in HSCs impairs their function, acute IFN treatment promotes the proliferation of dormant HSCs in vivo. These data may help to clarify the so far unexplained clinical effects of IFN on leukemic cells and raise the possibility for novel applications of type I interferons to target cancer stem cells.
Publication Title
IFNalpha activates dormant haematopoietic stem cells in vivo.
Sample Metadata Fields
Specimen part, Time
View Samples- 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, Homo sapiens
- 22 Downloadable Samples
Description
All highly and poorly permeable metastases from the same mouse brain were collected by laser capture microdissection. Total RNA from both metastatic lesions and immediate microenvironment was isolated from 5 mice bearing 231-BR metastases. As control 4 healthy mouse brains were included.
Publication Title
Reactive astrocytic S1P3 signaling modulates the blood-tumor barrier in brain metastases.
Sample Metadata Fields
Subject
View Samples- Mus musculus
- 69 Downloadable Samples
Description
The polytrauma (PT) murine model has unique transcriptomic responses 2 hrs, 1 day and 3 days after injury. We determined with this clinically relevant model that the increased morbidity in the elderly is secondary to a failure of bone marrow progenitors, blood neutrophils, and bronchoalveolar lavage cells to initiate and complete an 'emergency myelopoietic' response, engendering myeloid cells that fail to clear secondary infection. In addition, the elderly appear unable to effectively resolve their inflammatory response to severe injury.
Publication Title
A Detailed Characterization of the Dysfunctional Immunity and Abnormal Myelopoiesis Induced by Severe Shock and Trauma in the Aged.
Sample Metadata Fields
Sex, Specimen part, Treatment
View Samples