This SuperSeries is composed of the SubSeries listed below.
The thrombopoietin/MPL axis is activated in the Gata1<sup>low</sup> mouse model of myelofibrosis and is associated with a defective RPS14 signature.
Sex
View SamplesMyelofibrosis (MF) is caused by genetic abnormalities involving the thrombopoietin (TPO)/MPL/JAK2 axis. Furthermore MF patients have elevated serum TPO levels. MF is also associated with reduced GATA1 content in MK suggesting that this abnormality represents a phenotypic modifier. In 2014, Dr. Crispino suggested that in MF abnormal TPO signaling induces a ribosomal deficiency hampering GATA1 mRNA translation in MK. Support for MK GATA1 deficiency as phenotypic modifier in MF was provided by the observation that mice carrying the Gata1low mutation reducing Gata1 transcription in MK develop myelofibrosis. Since reduced RBC half-life subject these mice to continuous erythroid stress, we investigated the TPO/Mpl axis in this model. In Gata1low and wild-type mice, TPO mRNA was expressed by bone marrow (BM), spleen and liver. The greatest expression (by 300-fold) was detected in liver. Gata1low livers expressed TPO mRNA levels 6-fold greater than wild-type livers. TPO protein was detected in BM, spleen, liver and peritoneum washes and plasma. The greatest levels where detected in plasma. Gata1low plasma contained TPO levels 2-fold lower than wild-type plasma, but 2-times greater than plasma from bleed wild-type mice and Mplnull mice with similar thrombocytopenia, suggesting that TPO is overproduced in Gata1low mice. JAK2 and STAT5 were easily detected in Gata1low BM bur barely detectable in wild-type BM, suggesting that in the former MPL is prompt to signaling activation. Furthermore, Gata1low LSK expressed levels of Mpl mRNA 3-times greater than wild-type cells but expressed cell-surface levels of MPL 2-times lower than wild-type cells and similar to those on LSK from TPO-treated wild-type mice, suggesting that MPL is down-modulated in Gata1low LSK. The Crispinos hypothesis that in MF activation of TPO/MPL/JAK2 induces a ribosomal deficiency hampering GATA1 mRNA translation and the realization that this axis is activated in Gata1low mice made us question the original hypothesis that reduced content of GATA1 in Gata1low MK results from deletion of lineage-specific enhancers. Microarray analyses indeed identified that Gata1low BM express a discordant ribosome signature including reduced expression of RPS24 and RPS36A, two genes mutated in Diamond Blackfan Anemia, a disease characterized by inefficient GATA1 mRNA translation. Electron microscopy identified that the cytoplasm of Gata1low MK contained poorly developed endoplasmic reticulum with rare polysomes. In conclusion, these results validate the Gata1low model as a MF model by indicating that these mice express an activated TPO/MPL axis and an abnormal ribosomal signature which may reduce efficiency of Gata1 mRNA translation.
The thrombopoietin/MPL axis is activated in the Gata1<sup>low</sup> mouse model of myelofibrosis and is associated with a defective RPS14 signature.
Sex
View SamplesMyelofibrosis (MF) is caused by genetic abnormalities involving the thrombopoietin (TPO)/MPL/JAK2 axis. Furthermore MF patients have elevated serum TPO levels. MF is also associated with reduced GATA1 content in MK suggesting that this abnormality represents a phenotypic modifier. In 2014, Dr. Crispino suggested that in MF abnormal TPO signaling induces a ribosomal deficiency hampering GATA1 mRNA translation in MK. Support for MK GATA1 deficiency as phenotypic modifier in MF was provided by the observation that mice carrying the Gata1low mutation reducing Gata1 transcription in MK develop myelofibrosis. Since reduced RBC half-life subject these mice to continuous erythroid stress, we investigated the TPO/Mpl axis in this model. In Gata1low and wild-type mice, TPO mRNA was expressed by bone marrow (BM), spleen and liver. The greatest expression (by 300-fold) was detected in liver. Gata1low livers expressed TPO mRNA levels 6-fold greater than wild-type livers. TPO protein was detected in BM, spleen, liver and peritoneum washes and plasma. The greatest levels where detected in plasma. Gata1low plasma contained TPO levels 2-fold lower than wild-type plasma, but 2-times greater than plasma from bleed wild-type mice and Mplnull mice with similar thrombocytopenia, suggesting that TPO is overproduced in Gata1low mice. JAK2 and STAT5 were easily detected in Gata1low BM bur barely detectable in wild-type BM, suggesting that in the former MPL is prompt to signaling activation. Furthermore, Gata1low LSK expressed levels of Mpl mRNA 3-times greater than wild-type cells but expressed cell-surface levels of MPL 2-times lower than wild-type cells and similar to those on LSK from TPO-treated wild-type mice, suggesting that MPL is down-modulated in Gata1low LSK. The Crispinos hypothesis that in MF activation of TPO/MPL/JAK2 induces a ribosomal deficiency hampering GATA1 mRNA translation and the realization that this axis is activated in Gata1low mice made us question the original hypothesis that reduced content of GATA1 in Gata1low MK results from deletion of lineage-specific enhancers. Microarray analyses indeed identified that Gata1low BM express a discordant ribosome signature including reduced expression of RPS24 and RPS36A, two genes mutated in Diamond Blackfan Anemia, a disease characterized by inefficient GATA1 mRNA translation. Electron microscopy identified that the cytoplasm of Gata1low MK contained poorly developed endoplasmic reticulum with rare polysomes. In conclusion, these results validate the Gata1low model as a MF model by indicating that these mice express an activated TPO/MPL axis and an abnormal ribosomal signature which may reduce efficiency of Gata1 mRNA translation.
The thrombopoietin/MPL axis is activated in the Gata1<sup>low</sup> mouse model of myelofibrosis and is associated with a defective RPS14 signature.
Sex
View SamplesIn homeostasis of adult vertebrate tissues, stem cells are thought to self-renew by infrequent and asymmetric divisions that generate another stem cell daughter and a progenitor daughter cell committed to differentiate. This model is based largely on in vivo invertebrate or in vitro mammal studies. Here we examine the dynamic behaviour of adult hair follicle stem cells in their normal setting by employing mice with repressible H2B-GFP expression to track cell divisions and Cre inducible mice to perform long-term single cell lineage tracing. We provide direct evidence for the infrequent stem cell division model in intact tissue. Moreover, we find that differentiation of progenitor cells occurs at different times and tissue locations than self-renewal of stem cells. Distinct fates of differentiation or self-renewal are assigned to individual cells in a temporal-spatial manner. We propose that large clusters of tissue stem cells behave as populations, whose maintenance involves unidirectional daughter-cell fate decisions.
Distinct self-renewal and differentiation phases in the niche of infrequently dividing hair follicle stem cells.
Specimen part
View SamplesPurpose: Next-generation sequencing (NGS) has revolutionized systems-based analysis of cellular pathways. The goals of this study was to obtain the trasncriptome of DGCR8_KO mESCs to compare it with the transcriptome of WT mESCs (deposit separately). Overall design: mRNA profiles of DGCR8_KO mouse embryonic stem cells were generated by deep sequencing, in duplicate, using Illumina HiSeq2000.
Noncanonical function of DGCR8 controls mESC exit from pluripotency.
Specimen part, Cell line, Subject
View SamplesOvarian cancer patients are generally diagnosed at stage III/IV, when ascites is common. The volume of ascites positively correlates with the extent of metastasis and negatively with prognosis. Membrane GRP78, a stress-inducible endoplasmic reticulum chaperone which also appears on the plasma membrane (memGRP78) of aggressive cancers, plays a crucial role in the maintenance of embryonic stem cells. Our present study demonstrates that tumor cells isolated from ascites generated by epithelial ovarian cancer (ID8 cells) bearing mice have increased memGRP78 expression compared to ID8 cells in normal culture. We hypothesize that these ascites associated memGRP78+ cells are cancer stem-like cells (CSC) and memGRP78 is functionally important in CSCs. Supporting this hypothesis, we show that memGRP78+ cells isolated from ascites have increased sphere forming and tumor initiating abilities compared to memGRP78- cells. When the tumor microenvironment is recapitulated by adding ascites fluid to cell culture, ID8 cells express more memGRP78 and increased self-renewing ability compared to those cultured in medium alone. Moreover, compared to their counterparts cultured in normal medium, ID8 cells cultured in ascites, or isolated from ascites, show an increased expression of stem cell markers Sca-1, Snail and SOX9. Importantly, antibodies directed against the carboxy (COOH)-terminal domain of GRP78 significantly reduce the self-renewing ability of murine and human ovarian cancer cells pre-incubated with ascites, associated with a decreased phosphorylation of Akt and GSK3, and reduced level of the transcriptional factor Snail. Based on this data, we suggest that memGRP78 is a logical therapeutic target for late stage ovarian cancer.
Syngeneic Murine Ovarian Cancer Model Reveals That Ascites Enriches for Ovarian Cancer Stem-Like Cells Expressing Membrane GRP78.
Disease
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gene expression patterns related to osteogenic differentiation of bone marrow-derived mesenchymal stem cells during ex vivo expansion.
No sample metadata fields
View SamplesThe aim of this study was to describe the gene expression patterns related to the differentiation and mineralization of bone-forming cells, including activation and/or repression of osteogenic or non-osteogenic pathways, remodeling of cell architecture, cell adhesion, cell communication, and assembly of extracellular matrix. The study implied patient selection, tissue collection, isolation and culture of human marrow stromal cells (hMSC) and osteoblasts (hOB), and characterization of bone-forming cells. RNA samples were collected at defined time points, in order to understand the regulation of gene expression during the processes of cell differentiation/mineralization that occur during bone repair. Transcriptome analysis was performed by using the Affymetrix GeneChip microarray technology platform and GeneChip Human Genome U133 Plus 2.0 Array. Our results help to design a gene expression profile of bone-forming cells during specific steps of osteogenic differentiation. These findings offer an useful tool to monitor the behaviour of osteogenic precursors cultured in presence of exogenous stimuli, i.e. growth factors, or onto 3D scaffolds for bone engineering. Moreover, they can contribute to identify and clarify the role of new genes for a better understanding of the molecular mechanisms regulating osteogenesis.
Gene expression patterns related to osteogenic differentiation of bone marrow-derived mesenchymal stem cells during ex vivo expansion.
No sample metadata fields
View SamplesThe aim of this study was to describe the gene expression patterns related to the differentiation and mineralization of bone-forming cells, including activation and/or repression of osteogenic or non-osteogenic pathways, remodeling of cell architecture, cell adhesion, cell communication, and assembly of extracellular matrix. The study implied patient selection, tissue collection, isolation and culture of human marrow stromal cells (hMSC) and osteoblasts (hOB), and characterization of bone-forming cells. RNA samples were collected at defined time points, in order to understand the regulation of gene expression during the processes of cell differentiation/mineralization that occur during bone repair. Transcriptome analysis was performed by using the Affymetrix GeneChip microarray technology platform and GeneChip Human Genome U133 Plus 2.0 Array. Our results help to design a gene expression profile of bone-forming cells during specific steps of osteogenic differentiation. These findings offer an useful tool to monitor the behaviour of osteogenic precursors cultured in presence of exogenous stimuli, i.e. growth factors, or onto 3D scaffolds for bone engineering. Moreover, they can contribute to identify and clarify the role of new genes for a better understanding of the molecular mechanisms regulating osteogenesis.
Gene expression patterns related to osteogenic differentiation of bone marrow-derived mesenchymal stem cells during ex vivo expansion.
No sample metadata fields
View SamplesThe aim of this study was to describe the gene expression patterns related to the differentiation and mineralization of bone-forming cells, including activation and/or repression of osteogenic or non-osteogenic pathways, remodeling of cell architecture, cell adhesion, cell communication, and assembly of extracellular matrix. The study implied patient selection, tissue collection, isolation and culture of human marrow stromal cells (hMSC) and osteoblasts (hOB), and characterization of bone-forming cells. RNA samples were collected at defined time points, in order to understand the regulation of gene expression during the processes of cell differentiation/mineralization that occur during bone repair. Transcriptome analysis was performed by using the Affymetrix GeneChip microarray technology platform and GeneChip Human Genome U133 Plus 2.0 Array. Our results help to design a gene expression profile of bone-forming cells during specific steps of osteogenic differentiation. These findings offer an useful tool to monitor the behaviour of osteogenic precursors cultured in presence of exogenous stimuli, i.e. growth factors, or onto 3D scaffolds for bone engineering. Moreover, they can contribute to identify and clarify the role of new genes for a better understanding of the molecular mechanisms regulating osteogenesis.
Gene expression patterns related to osteogenic differentiation of bone marrow-derived mesenchymal stem cells during ex vivo expansion.
No sample metadata fields
View Samples