Pericytes derived from skin dermis can substantially enhance the short-term tissue-regenerative capacity of human epidermal cells already committed to differentiation; they also display both phenotypic and functional properties of mesenchymal stem cells. In this microarray analysis, we compared the gene expression profile of dermal pericytes to that of the remaining dermal cells of neonatal human foreskin.
A role for pericytes as microenvironmental regulators of human skin tissue regeneration.
Specimen part
View SamplesTranscriptome of murine testis from wild type mice and mice lacking telomerase for three generations (G3-Terc), Ku86 or both telomerase and Ku86.
Effectors of mammalian telomere dysfunction: a comparative transcriptome analysis using mouse models.
No sample metadata fields
View SamplesWe profiled total mRNA of pancreas and kidney tissues of 3 different strains (p53-null; In4a/Arf-null and WT) of reprogrammable mouse lines (they all express OCT4, SOX2, KLF4, C-MYC under the control of a tetracycline promoter, activated by doxycycline) Overall design: 5 mice of each genotype were treated with doxycycline to induce the expression of the reprogramming factors, they were sacrificed and total mRNA was extracted from pancreas and kidney tissues (we mapped >24M reads per sample)
Tissue damage and senescence provide critical signals for cellular reprogramming in vivo.
Specimen part, Cell line, Subject
View SamplesWhe embryonic stem cells are in vitro expanded threir telomereres lengthen, in the absence of genetic manipulations, concomitant with the loss of heterochromatic marks. In order to analyze whether there would be changes in gene expression during in vitro expansion we performed RNA-seq and found no substantial differences in gene expression at passage 6 or 16. Overall design: Embryonic stem (ES) cells were derived from blastocysts expressing GFP in the Rosa26 locus. Four independent lines of ES were in vitro expanded to passage 16. Total RNA was extracted from each independent clones, RNA was extracted and prepared for RNA-seq.
Generation of mice with longer and better preserved telomeres in the absence of genetic manipulations.
Specimen part, Cell line, Treatment, Subject
View SamplesRecent studies suggest that telomerase promotes cell growth by mechanisms that extend beyond the rescue of critically short telomeres. The in vitro model of mTert overexpressing MEFs recapitulates fundamental aspects of the growth-promoting effects of mTert in vivo. First, in Terc-proficient cells, mTert overexpression favors escape from replicative senescence and enhances anchorage-independent growth in response to oncogenic stress, which fits well with previous data showing that mTert overexpression promotes tumor formation. Second, in Terc-deficient cells, retroviral transduction with mTert results in a delayed onset of immortalization and impairs colony formation in response to oncogenic stress, which is in agreement with the inhibitory effect of mTert overexpression on tumorigenesis in a Terc null mouse background. To unravel the molecular targets of telomerase that impact on cell growth, we compared the transcriptome of MEFs, before and after mTert introduction. We found that ectopic expression of mTert was associated with detectable gene expression changes (greater than 1.5-fold; validated by qRT-PCR) of 26 transcripts. Analysis of the observed transcriptional changes indicates that ectopic expression of mTert suppresses in a coordinated manner functionally related genes with overlapping roles in growth arrest, resistance to transformation, and apoptosis. We show that the majority of the telomerase target genes are growth-inhibitory, transforming growth factor-beta (TGF-beta) -inducible genes and provide functional evidence for the potential of telomerase to abrogate TGF-beta -mediated growth inhibition. Thus, in line with the current view that the diversity of TGF-beta responses is not so much a consequence of the use of different signaling pathways but caused by different ways of reading the output from the same basic pathway, we propose that the telomerase status of a cell creates a gene expression pattern that determines how cells read growth inhibitory signals, among them signals propagated through the TGF-beta pathway.
Expression of mTert in primary murine cells links the growth-promoting effects of telomerase to transforming growth factor-beta signaling.
No sample metadata fields
View SamplesThe basic defect of IgA nephropathy (IgAN) lies within peripheral blood mononuclear cells rather than local kidney abnormalities. Previously we showed an altered gene expression in monocytes compared to B and T cells isolated from IgAN patients (Kidney Int, 2010), thus our aim here was to study this subset more closely at genome-wide level.
Altered monocyte expression and expansion of non-classical monocyte subset in IgA nephropathy patients.
Specimen part, Disease
View SamplesGene expression from bone-marrow drived macrophages of WT and SREBP-1a deficient mice
Linking lipid metabolism to the innate immune response in macrophages through sterol regulatory element binding protein-1a.
No sample metadata fields
View SamplesAlthough glucocorticoids (GCs) are known to exert numerous effects in the hippocampus, their chronic regulatory functions remain poorly understood. Moreover, evidence is inconsistent regarding the longstanding hypothesis that chronic GC exposure promotes brain aging/Alzheimer's disease. Here, we adrenalectomized male F344 rats at 15-months-of-age, maintained them for 3 months with implanted corticosterone (CORT) pellets producing low or intermediate (glucocorticoid-receptor (GR)-activating) blood levels of CORT, and performed microarray/pathway analyses in hippocampal CA1. We defined the chronic GC-dependent transcriptome as 393 genes that exhibited differential expression between Intermediate- and Low-CORT groups. Short-term CORT (4 days) did not recapitulate this transcriptome. Functional processes/pathways overrepresented by chronic CORT-upregulated genes included learning/plasticity, differentiation, glucose metabolism and cholesterol biosynthesis, whereas processes overrepresented by CORT-downregulated genes included inflammatory/immune/glial responses and extracellular structure. These profiles indicate that GCs chronically activate neuronal/metabolic processes while coordinately repressing a glial axis of reactivity/inflammation. We then compared the GC-transcriptome with a previously-defined hippocampal aging transcriptome, revealing a high proportion of common genes. Although CORT and aging moved expression of some common genes in the same-direction, the majority were shifted in opposite directions by CORT and aging (e.g., glial inflammatory genes downregulated by CORT are upregulated with aging). These results contradict the hypothesis that GCs simply promote brain aging, and also suggest that the opposite-direction shifts during aging reflect resistance to CORT regulation. Therefore, we propose a new model in which aging-related GC resistance develops in some target pathways while GC overstimulation develops in others, together generating much of the brain aging phenotype.
Glucocorticoid-dependent hippocampal transcriptome in male rats: pathway-specific alterations with aging.
Sex, Age, Specimen part
View SamplesPluripotent stem cells are derived from culture of early embryos or the germline, and can be induced by reprogramming of somatic cells. Barriers to reprogramming are expected to exist that stabilize the differentiated state and have tumor suppression functions. However, we have a limited understanding of what such barriers might be. To find novel barriers to reprogramming to pluripotency, we compared the transcriptional profiles of the mouse germline to pluripotent and somatic cells, in vivo and in vitro. There is a remarkable global expression of the transcriptional program for pluripotency in Primordial Germ Cells (PGCs). We identify parallels between PGCs reprogramming to pluripotency and human germ cell tumorigenesis, including the loss of LATS2, a tumor suppressor kinase of the Hippo pathway. We show that knockdown of LATS2 increases the efficiency of induction of pluripotency in human cells. LATS2 RNAi, unlike p53 RNAi, specifically enhances the generation of fully reprogrammed iPS cells without accelerating cell proliferation. We further show that LATS2 represses reprogramming in human cells by post-transcriptionally antagonizing TAZ but not YAP, two downstream effectors of the Hippo pathway. These results reveal transcriptional parallels between germ cell transformation and the generation of iPS cells, and indicate that the Hippo pathway constitutes a barrier to cellular reprogramming.
Transcriptional analysis of pluripotency reveals the Hippo pathway as a barrier to reprogramming.
Sex, Specimen part
View SamplesThis study characterizes the response of primary human endothelial cells (human umbilical vein endothelial cells, HUVECs) to the relative shear stress changes that occur during the initiation of arteriogenesis at the entrance regions to a collateral artery network. HUVECs were preconditioned to a baseline level of unidirectional shear of 15 dynes/cm2 for 24 hours. After 24 hours preconditioning, HUVECs were subjected to an arteriogenic stimulus that mimics the shear stress changes observed in the opposing entrance regions into a collateral artery network. The arteriogenic stimulus consisted of a 100% step wise increase in shear stress magnitude to a unidirectional 30 dynes/cm2 in either the same or opposite direction of the preconditioned shear stress. This simulates either the feeding entrance to the collateral artery circuit or the region that drains into the vasculature downstream of an obstruction in a major artery, respectively. In vivo analysis of collateral growth in the mouse hindlimb showed enhanced outward remodeling in the re-entrant (direction reversing) region that reconnects to the downstream arterial tree, suggesting reversal of shear stress direction as a key enhancer of arteriogenesis. Transcriptional profiling using microarray techniques identified that the reversal of shear stress direction, but not an increase in shear stress alone, yielded a broad-based enhancement of the mechanotransduction pathways necessary for the induction of arteriogenesis.
Mechanisms of Amplified Arteriogenesis in Collateral Artery Segments Exposed to Reversed Flow Direction.
Specimen part
View Samples