Human aging is associated with loss of function and regenerative capacity. Human bone marrow derived mesenchymal stromal cells (hMSCs) are involved in tissue regeneration, evidenced by their capacity to differentiate into several lineages and therefore are considered the gold standard for cell-based regeneration therapy. Tissue maintenance and regeneration is dependent on stem cells and declines with age and aging is thought to influence therapeutic efficacy, therefore, more insight in the process of aging of hMSCs is of high interest. We, therefore, hypothesized that hMSCs might reflect signs of aging. In order to find markers for donor age, early passage hMSCs were isolated from bone marrow of 61 donors, with ages varying from 17-84, and clinical parameters, in vitro characteristics and microarray analysis were assessed. Although clinical parameters and in vitro performance did not yield reliable markers for aging since large donor variations were present, genome-wide microarray analysis resulted in a considerable list of genes correlating with human age. By comparing the transcriptional profile of aging in human with the one from rat, we discovered follistatin as a common marker for aging in both species. The gene signature presented here could be a useful tool for drug testing to rejuvenate hMSCs or for the selection of more potent, hMSCs for cell-based therapy.
A mesenchymal stromal cell gene signature for donor age.
Sex, Age
View SamplesTo provide further insight about the effects of prolonged Ezh2 inhibition in glioblastoma using preclinical mouse models and doxycycline-inducible shRNAs that mimic the effects of a selective EZH2 inhibitor. We demonstrate that prolonged Ezh2-depletion causes a robust switch in cell fate, including significantly enhanced proliferation and DNA damage repair and activation of part of the pluripotency network, resulting in altered tumor cell identity and tumor progression. Overall design: SVZ derived neural stem cells (NSCs) were isolated from 7 days old p53;Ink4a/Arf;Krasv12;LucR compound conditional mice and cultured in NSC specific serum-free medium supplemented with 20ng/ml of both EGF and bFGF (R&D systems). NSCs were grown adhesion-free for the first passages to eliminate non-sphere-forming cells. Next, cells were grown adherent on poly-L-Ornithine and Laminin plates and three times infected with lentiviral CMV-Cre. These floxed, tumorigenic cells are further referred as glioma initiating cells (GICs). Next, GICs were infected with a tet-inducible, doxycycline-responsive short hairpin construct (FH1-tUTG-shEzh2). After FACS sorting for GFP, GICs were injected intracranial in NOD-SCID mice and treated with or without doxycycline in the drinking water
Prolonged Ezh2 Depletion in Glioblastoma Causes a Robust Switch in Cell Fate Resulting in Tumor Progression.
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View SamplesPreviously, it has been demonstrated that formate can be utilized by Saccharomyces cerevisiae as additional energy source using cells grown in a glucose-limited chemostat. Here, we investigated utilization of formaldehyde as co-substrate. Since endogenous formaldehyde dehydrogenase activities were insufficient to allow co-feeding of formaldehyde, the Hansenula polymorpha FLD1, encoding formaldehyde dehydrogenase, was introduced in S. cerevisiae. Chemostat cultivations revealed that formaldehyde was co-utilized with glucose, but the yield was lower than predicted. Moreover, formate was secreted by the cells. Upon co-expression of the H. polymorpha gene encoding formate dehydrogenase, FMD, the levels of secreted formate decreased, but the biomass yield was still lower than anticipated.
Engineering and analysis of a Saccharomyces cerevisiae strain that uses formaldehyde as an auxiliary substrate.
No sample metadata fields
View SamplesExtremely low specific growth rates (below 0.01 h-1) represent a largely unexplored area of microbial physiology. Retentostats enable controlled, energy-limited cultivation at near-zero specific growth rates while avoiding starvation. In this study, anaerobic, glucose-limited retentostats were used to analyze physiological and genome-wide transcriptional responses of Saccharomyces cerevisiae to cultivation at near-zero specific growth rates. Cultures at near-zero specific growth rates exhibited several characteristics previously associated with quiescence, including accumulation of storage polymers and an increased expression of genes involved in storage metabolism, autophagy and exit from the replicative cell cycle into G0. Analysis of transcriptome data from glucose-limited retentostat and chemostat cultures showed, as specific growth rate was decreased, quiescence-related transcriptional responses already set in at specific growth rates above 0.025 h-1. Many genes involved in mitochondrial processes were specifically upregulated at near-zero specific growth rates, possibly reflecting an increased turn-over of organelles under these conditions. Prolonged (> 2 weeks) cultivation in retentostat cultures led to induction of several genes that were previously implicated in chronological ageing. These observations stress the need for systematic dissection of physiological responses to slow growth, quiescence, ageing and starvation and indicate that controlled cultivation systems such as retentostats can contribute to this goal.
Cellular responses of Saccharomyces cerevisiae at near-zero growth rates: transcriptome analysis of anaerobic retentostat cultures.
No sample metadata fields
View SamplesIn parallel with the inconsistency in observational studies and chemoprevention trials, the molecular mechanisms by which selenium may affect prostate cancer risk have not been elucidated. We conducted a randomized, placebo-controlled intervention trial to examine the effects of a short-term intervention with selenized yeast on whole-genome expression profiles in non-malignant prostate tissue. Twenty-three men receiving prostate biopsies were randomly assigned to take 300 g selenized yeast per day (n=12) or placebo (non-selenized yeast, n=11) during a median intervention period of 35 (interquartile range: 31-35) days. Prostate specimens, collected from the transition zone before and after intervention, of 15 participants (n=8 selenium, n=7 placebo) were available for analysis using Affymetrix GeneChip Human 1.0 ST Arrays. Pathway and gene set enrichment analyses revealed that the intervention with selenium resulted in a down-regulated expression of genes involved in signaling pathways related to cellular adhesion, migration, invasion, remodeling and immune responses. Specifically, expression of the well-established epithelial marker E-cadherin was up-regulated, while mesenchymal markers, such as vimentin and fibronectin, were down-regulated after the intervention with selenium. This implies an effect of selenium on the epithelial-to-mesenchymal transition (EMT). Moreover, selenium affected expression of genes involved in wound healing and inflammation, processes which are both related to EMT. In conclusion, our data showed that selenium affected expression of genes implicated in EMT, mainly represented by a change in the direction of the epithelial rather than the mesenchymal phenotype.
A short-term intervention with selenium affects expression of genes implicated in the epithelial-to-mesenchymal transition in the prostate.
Sex, Specimen part, Time
View SamplesRat small intestine precision cut slices were exposed for 6 hours to in vitro digested yellow (YOd) and white onion extracts (WOd) that was followed by transcriptomics analysis. The digestion was performed to mimic the digestion that in vivo takes place in the stomach and small intestine. The transcriptomics response of the rat small intestine precision cut slices was compared to that of human Caco-2 cells and the pig in-situ small intestinal segment perfusion. The microarray data for the human Caco-2 cells (GSE83893) and the pig in-situ small intestinal segment perfusion (GSE83908) have been submitted separately from the current data on rat intestine. The goal was to obtain more insight into to which extent mode of actions depend on the experimental model. A main outcome was that each of the three models pointed to the same mode of action: induction of oxidative stress and particularly the Keap1-Nrf2 pathway.
Effects of Digested Onion Extracts on Intestinal Gene Expression: An Interspecies Comparison Using Different Intestine Models.
Sex, Age, Specimen part
View SamplesBackground: Human intestinal tissue samples are barely accessible to study potential health benefits of nutritional compounds. Numbers of animals used in animal trials, however, need to be minimalized. Therefore, in this study we explored the applicability of an in vitro model, namely human intestinal Caco-2 cells, to study the effect of food compounds on (intestinal) health. In vitro digested yellow (YOd) and white onion extracts (WOd) were used as model food compounds and transcriptomics was applied to obtain more insight into their mode of actions in the intestinal cells. Methods: Caco-2 cells were incubated with in vitro digested onion extracts for 6 hours, total RNA was extracted and Affymterix Human Gene 1.1 ST arrays were used to analyze the gene expression profiles. To identify onion-induced gene expression profiles in Caco-2 cells, digested yellow onion and white onion samples were compared to a digest control samples. Results: We found that yellow onion (n=5586, p<0.05) had a more pronounced effect on gene expression than white onion (n=3688, p<0.05). However, a substantial number of genes (n=3281, p<0.05) were affected by both onion variants in the same direction. Pathway analyses revealed that mainly processes related to oxidative stress, and especially the Keap1-Nrf2 pathway, were affected by onions. Our data fit with previous in vivo studies showing that the beneficial effects of onions are mostly linked to their antioxidant properties. Conclusion: our data indicate that the in vitro Caco-2 intestinal model can be used to determine modes of action of nutritional compounds and can thereby reduce the number of animals used in conventional nutritional intervention studies.
Effects of Digested Onion Extracts on Intestinal Gene Expression: An Interspecies Comparison Using Different Intestine Models.
Cell line
View SamplesSince the discovery of induced pluripotent stem cells there has been intense interest in understanding the mechanisms that allow a somatic cell to be reprogrammed back to a pluripotent state. Several groups have studied the alterations in gene expression that occur as somatic cells modify their genome to that of an embryonic stem cell. Underpinning many of the gene expression changes are modifications to the epigenetic profile of the associated chromatin. We have used a large-scale shRNA screen to identify epigenetic modifiers that act as barriers to reprogramming. We have uncovered an important role for TRIM28 in cells resisting transition between somatic and pluripotent states. TRIM28 achieves this by maintaining the H3K9me3 repressed state and keeping endogenous retroviruses silenced. We propose that knockdown of TRIM28 during reprogramming results in more plastic H3K9me3 domains, dysregulation of genes nearby H3K9me3 marks, and up regulation of endogenous retroviruses, thus facilitating the transition through reprogramming. Overall design: Gene expression profiling using high through put sequencing at day 7 of Oct4, Sox2, Klf4 and cMyc (OSKM) expression in mouse embryonic fibroblasts with or without Trim28 / Setdb1 knockdown
TRIM28 is an Epigenetic Barrier to Induced Pluripotent Stem Cell Reprogramming.
Specimen part, Cell line, Treatment, Subject
View SamplesWe wanted to understand the consequences of GSK126-mediated Ezh2 inhibition in an orthotopic model of Kras-driven non-small cell lung cancer (NSCLC). We injected the NSCLC cells with above-mentioned genotype into Nude mice and treated them with GSK126 50mg/kg (daily) or vehicle. As additional control for Ezh2 specificity we treated one tumor with doxycycline that induces shRNA-mediated Ezh2 protein downregulation in those cells. Purified tumour cells were obtained by dissection and FACS sorting based of GFP expression. This experiment contributes the genome-wide response of NSCLC cells to Ezh2 inhibition in vivo. Overall design: We generated mRNA profiles of tumor cells tail vein injected into the lungs of Nude mice by deep sequencing. After FACS purification, RNA extraction and Bioanalyzer analysis, we processed only samples with high quality cellular and RNA profiles. Overall, we compared 10-day GSK126 treated cells (n=4) and up to 30 days GSK126 treated cells (n=3) to Captisol-treated samples (vehicle, n=2), using Illumina Hiseq2000. FACS sorted cells from individual animals were obtained by GFP expression. For H3K27ac and H2AK5ac profiling, we used KP primary tumors generated by injection of NSCLC into the tail vein of nude mice. Mice were sacrificed on the onset of shortness of breath and tissues were resuspended in ChIP lysis buffer.
Ezh2 inhibition in Kras-driven lung cancer amplifies inflammation and associated vulnerabilities.
No sample metadata fields
View SamplesRNA-seq and ChIP-seq on MCF-7 breast cancer cell line upon activation of p53 by the non-genotoxic small molecule Nutlin-3a Overall design: RNA-seq on MCF7 without (NS) or with Nutlin-3a stimulation (S), in duplicate, using illumina HiSeq 2000
iRegulon: from a gene list to a gene regulatory network using large motif and track collections.
Specimen part, Cell line, Subject
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