In 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
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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 SamplesSevere malnutrition in young children is associated with signs of hepatic dysfunction such as steatosis and hypoalbuminemia, but its etiology is unknown. To investigate the underlying mechanisms of hepatic dysfunction we used a rat model of malnutrition by placing weanling rats on a low protein or control diet (5% or 20% of calories from protein, respectively) for four weeks. Low protein diet-fed rats developed hypoalbuminemia and severe hepatic steatosis, consistent with the human phenotype. Hepatic peroxisome content was decreased and metabolomic analysis indicated impaired peroxisomal function. Loss of peroxisomes was followed by accumulation of dysfunctional mitochondria and decreased hepatic ATP levels. Fenofibrate supplementation restored hepatic peroxisome abundance and increased mitochondrial fatty acid -oxidation capacity, resulting in reduced steatosis and normalization of ATP and plasma albumin levels. These findings provide important insight into the metabolic
Malnutrition-associated liver steatosis and ATP depletion is caused by peroxisomal and mitochondrial dysfunction.
Sex, Specimen part, Treatment
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 SamplesRNA seq was performed comparing SC-specific Dicer mutants with SC-specific Lin28B transgenics to obtain an unbiased list of potentially de-regulated miRNA target candidates. Overall design: total RNA from sciatic nerves of P1 Dicer mutants, P1 Lin28 transgenics and their respective controls was used to perform RNA sequencing analysis.
The Lin28/let-7 axis is critical for myelination in the peripheral nervous system.
No sample metadata fields
View SamplesLong interspersed elements 1 (LINE-1 or L1) are retrotransposons that dominate the mouse genomic landscape, and are expressed in Embryonic Stem Cells (ESCs), germ cells, and during early development. Based on clear precedents in plants and fission yeast, we investigated in this study a role for RNAi and other RNA degradation pathways in the regulation of L1 expression and mobilization. We uncovered the existence of novel small (s)RNAs that map to active L1 elements. Some of these sRNAs have characteristics of cognate short-interfering RNA populations, while others display length heterogeneity that evokes a biogenesis through a RNA surveillance pathway, in a Dicer-independent manner. We additionally found that genetic ablation of Dicer and the sRNA effector protein AGO2 has complex and profound consequences on L1 transcription and mobilization in ESCs, indicating that endogenous RNA interference (RNAi) pathway indeed maintain genomic integrity against L1 proliferation. Finally, we investigated the implication of L1 retrotransposition during ESC differentiation and propose that the mobilization of L1 elements in Dicer mutant ESCs could partially explain the inability of these cells to differentiate. Overall design: 2 samples examined: WT E14 and Dicer mutant mouse ESCs
RNAi-dependent and independent control of LINE1 accumulation and mobility in mouse embryonic stem cells.
Specimen part, Subject
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