The skin interfollicular epidermis (IFE) is the first barrier against the external environment and its maintenance is critical for survival. Two seemingly opposite theories have been proposed to explain IFE homeostasis. One posits that IFE is maintained by a long-lived slow-cycling stem cell (SC) population that give rise to short-lived transit-amplifying (TA) cell progeny, while the other suggests that homeostasis is achieved by a single committed progenitor (CP) that balances stochastic fate. Here, we probed the cellular heterogeneity within the IFE using two different inducible CREER targeting IFE progenitors. Quantitative analysis of clonal fate data and proliferation dynamics demonstrate the existence of two distinct proliferative cell compartments composed of slow-cycling SC and CP, both of which undergo population asymmetric self-renewal. However, following wounding, only SCs contribute substantially to the repair and long-term regeneration of the tissue, while CP cells make a minimal and transient contribution.
Distinct contribution of stem and progenitor cells to epidermal maintenance.
Specimen part
View SamplesThis study was designed to investigate the transcripts that are regulated by Twist1 in skin tymor epithelial cells in a p53-dependent and independent manner. To this aim, Tumor epithelial cells from primary mouse skin tumors of different genotypes were FACS sorted and analyzed by microarray.
Different levels of Twist1 regulate skin tumor initiation, stemness, and progression.
Specimen part, Treatment
View SamplesTranscriptional profile of control and VEGF overexpressing FACS-isolated CD34+ Cancer stem cells from DMBA/TPA induced skin tumours
A vascular niche and a VEGF-Nrp1 loop regulate the initiation and stemness of skin tumours.
No sample metadata fields
View SamplesReproducibility in research can be compromised by both biological and technical variation, but most of the focus is on removing the latter. Here we investigate the effects of biological variation in HeLa cell lines using a systems-wide approach. We determine the degree of molecular and phenotypic variability across 14 stock HeLa samples from 13 international laboratories. We cultured cells in uniform conditions and profiled genome-wide copy numbers, mRNAs, proteins and protein turnover rates in each cell line. We discovered substantial heterogeneity between HeLa variants, especially between lines of the CCL2 and Kyoto varieties, and observed progressive divergence within a specific cell line over 50 successive passages. Genomic variability has a complex, nonlinear effect on transcriptome, proteome and protein turnover profiles, and proteotype patterns explain the varying phenotypic response of different cell lines to Salmonella infection. These findings have implications for the interpretation and reproducibility of research results obtained from human cultured cells. Overall design: Multi-omic (genome, transcriptome, proteome, protein turnover) analysis of 14 HeLa cell lines obtained from different laboratories but grown under the same conditions.
Multi-omic measurements of heterogeneity in HeLa cells across laboratories.
Specimen part, Subject
View SamplesWhile the hypothalamo-pituitary-adrenal axis (HPA) activates a general stress response by increasing glucocorticoid (Gc) synthesis, biological stress resulting from infections triggers the inflammatory response through production of cytokines. The pituitary gland integrates some of these signals by responding to the pro-inflammatory cytokines IL6 and LIF and to a negative Gc feedback loop. The present work used whole-genome approaches to define the LIF/STAT3 regulatory network and to delineate cross-talk between this pathway and Gc action. Genome-wide ChIP-chip identified 3 449 STAT3 binding sites, whereas 2 396 genes regulated by LIF and/or Gc were found by expression profiling. Surprisingly, LIF on its own changed expression of only 85 genes but the joint action of LIF and Gc potentiated the expression of more than a thousand genes. Accordingly, activation of both LIF and Gc pathways also potentiated STAT3 and GR recruitment to many STAT3 targets. Our analyses revealed an unexpected gene cluster that requires both stimuli for delayed activation: 83% of the genes in this cluster are involved in different cell defense mechanisms. Thus, stressors that trigger both general stress and inflammatory responses lead to activation of a stereotypic innate cellular defense response.
Regulatory network analyses reveal genome-wide potentiation of LIF signaling by glucocorticoids and define an innate cell defense response.
Specimen part, Time
View SamplesPitx3 is a transcription factor that is expressed in all midbrain dopaminergic (mDA) neurons during early development, but later becomes restricted in dopaminergic subsets of substantia nigra compacta (SNc) and of the ventral tegmental are (VTA) that are vulnerable to neurodegenerative stress (MPTP, 6-OHDA, rotenone, Parkinson's disease). Overall, in mice, Pitx3 is required for developmental survival of ventral SNc neurons and for postnatal survival of VTA neurons (after postnatal day 40). With the aim of determining the gene networks that distinguish Pitx3-vulnerable (Pitx3-positive) from Pitx3-resistant (Pitx3-negative) subsets of SNc and VTA, we performed a comparison at the transcriptome level between FAC-sorted mDA neurons of SNc and VTA that were obtained from wild-type and Pitx3-/- newborn mice. The latter mice have already lost the majority of their TH+Calb1- mDA neurons of ventral SNc (Pitx3-dependent), but their TH+Calb1+ neurons of dorsal SNc (Pitx3-independent), including all of VTA neurons (50% are Pitx3-dependent and 50% Pitx3-independent), are unaffected by Pitx3 deletion. At postnatal day 40, Pitx3-/- mice display a marked loss of dopaminergic subsets of VTA that normally co-express Pitx3 and Calb1 (Pitx3-dependent neurons of VTA).
Rgs6 is required for adult maintenance of dopaminergic neurons in the ventral substantia nigra.
Specimen part
View SamplesAnalysis of the transcriptional profiles of mRNA and microRNA in Rasless fibroblasts. 4-Hydroxy-tamoxifen (4-OHT) treatment triggers removal of K-Ras expression in [H-Ras-/-;N-Ras-/-;K-Raslox/lox;RERTert/ert ] mouse fibroblasts (named K-Raslox) generating Rasless MEFs which are unable to proliferate, but recover proliferative ability after ectopic expression of constitutively active downstream kinases such as BRAF and MEK1.
Reversible, interrelated mRNA and miRNA expression patterns in the transcriptome of Rasless fibroblasts: functional and mechanistic implications.
Specimen part, Cell line, Treatment
View SamplesTo analyse and understand the differentially expressed genes following treatment with synthetic androgen (R1881) Overall design: LNCaP or LAPC4 cells were plated in RPMI 1640 media with no phenol red and with 5% charcoal stripped serum, sodium pyruvate, penicillin and streptomycin. After 48h (to allow adnrogen deprivation), fresh media was added, with 96% ethanol or the synthetic androgen R1881 (10nM concentration). 24h later, cells were harvested for RNA purification using the QIAGEN RNeasy plus purification kit. RNA was then enriched for mRNA and then sequenced.
RNA sequencing data of human prostate cancer cells treated with androgens.
Treatment, Subject
View SamplescJun is a transcription factor activated by phosphorylation by SAPK/JNK MAP kinase pathway that has been linked to atherosclerosis. Adenovirus mediated gene transfer of a dominant negative form of cJun in C57BL/6 mice increased greatly the apolipoprotein E (ApoE) mRNA and plasma apoE levels and induced dyslipidmia, characterized by increased plasma cholesterol, triglyceride and VLDL levels and accumulation of discoidal HDL particles. Unexpectedly, infection of ApoE-/- mice with adenovirus expressing dn-cJun reduced by 50% plasma cholesterol, suggesting that the dn-cJun affected other genes that control plamsa cholesterol. To determine the molecular pathways implicated in this process we performed whole genome expression profiling using total RNA from the liver of infected ApoE-/- mice.
A dominant negative form of the transcription factor c-Jun affects genes that have opposing effects on lipid homeostasis in mice.
No sample metadata fields
View SamplesAortic valve regurgitation (AR) imposes a severe volume overload to the left ventricle (LV) which results in dilation, eccentric hypertrophy and eventually loss of function. Little is known about the impact of AR on LV gene expression. We therefore conducted a gene expression profiling study in the LV of male Wistar rats with chronic (9 months) and severe AR.
Multiple short-chain dehydrogenases/reductases are regulated in pathological cardiac hypertrophy.
Sex
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