The skin is a protective barrier against external insults and any lesion must be rapidly and efficiently repaired. Dermal fibroblasts are the major source of extracellular connective tissue matrix and play an important role in wound healing. Vitamin C is an important water-soluble free radical scavenger and an essential cofactor for collagen synthesis by dermal fibroblasts and, consequently, may contribute to the maintenance of healthy skin. Using microarray analysis, we investigated the effects of long-term exposure to a stable vitamin C derivative, ascorbic acid 2-phosphate (AA2P), in contact-inhibited populations of primary human dermal fibroblasts. Compared with "scorbutic" cells, cells exposed to AA2P increased the expression of genes associated with DNA replication and repair and with the G(2)/M phase of the cell cycle. Consistent with the gene expression changes, AA2P increased the mitogenic stimulation of quiescent fibroblasts by serum factors and cell motility in the context of wound healing. Furthermore, AA2P-treated fibroblasts showed faster repair of oxidatively damaged DNA bases. We propose that vitamin C may protect the skin by promoting fibroblast proliferation, migration, and replication-associated base excision repair of potentially mutagenic DNA lesions, and we discuss the putative involvement of hypoxia-inducible transcription factor-1 and collagen receptor-related signaling pathways.
Gene expression profiling reveals new protective roles for vitamin C in human skin cells.
No sample metadata fields
View SamplesMature messenger RNAs (mRNAs) consist of coding sequence (CDS) and 5’ and 3’ untranslated regions, typically expected to show similar abundance within a given neuron. Examining mRNA from defined neurons we unexpectedly show extremely common unbalanced expression of cognate 3’ UTR and CDS sequences, observing many genes with high UTR relative to CDS, and others with high CDS to UTR. By in situ hybridization 19 of 19 genes examined show a broad range of UTR to CDS expression ratios in different neurons and other tissues. These ratios may be spatially graded or change with developmental age, but are consistent across animals. Further, for two genes examined, a UTR to CDS ratio above a particular threshold in any given neuron correlated with reduced or undetectable protein expression. Our findings raise questions about the role of isolated UTR sequences in regulation of protein expression, and highlight the importance of separately examining UTR and CDS sequences in gene expression analyses. Overall design: dopamine or serotonin neuronal mRNA was purified selectively by using dopamine transporter (DAT) and SLC6A4 (serotonin transporter) BacTrap mice. RNA sequencing was carried out using Illumina HiSeq 2500.
Widespread Differential Expression of Coding Region and 3' UTR Sequences in Neurons and Other Tissues.
Specimen part, Subject
View SamplesGene Expression analysis of a differentiation timeseries of human Mesenchymal Stem Cells (hMSCs) in the presence of adipogenic/osteogenic factors. hMSCs differentiate into fat cells when treated with dexamethasone (10^-6 M), insulin (10 ug/ml), rosiglitazone (10^-7 M) and IBMX (250 uM). TGFbeta (5 ng/ml) inhibits this process and redirects these cells to differentiate into bone cells.
TGFβ-induced switch from adipogenic to osteogenic differentiation of human mesenchymal stem cells: identification of drug targets for prevention of fat cell differentiation.
Specimen part, Treatment, Time
View SamplesPolybrominated diphenyl ethers (PBDEs) are commonly used as flame retardants in a variety of commercial and household products. They have been detected in the environment and accumulate in mammalian tissues and fluids. PBDE toxicity is thought to be associated with endocrine disruption, developmental neurotoxicity and changes in fetal development. Although humans are exposed to PBDEs, our knowledge of the effects of PBDE metabolites on human cells with respect to health risk is insufficient. Two hydroxylated PBDEs (OH-PBDEs), 2-OH-BDE47 and 2-OH-BDE85, were investigated for their effects on cell viability/proliferation, DNA damage, cell cycle distribution and gene expression profiling in H295R adrenocortical carcinoma cells. We show that the two agents are cytotoxic in a dose-dependent manner only at micromolar concentrations, with 2-OH-BDE85 being more toxic than 2-OH-BDE47. However, no DNA damage was observed for either chemical, suggesting that the biological effects of OH-PBDEs occur primarily via non-genotoxic routes. Furthermore, no evidence of aryl hydrocarbon receptor (AHR)-mediated, dioxin-like toxicity was observed. Instead, we report that a micromolar concentration of OH-PBDEs induces transcriptional changes associated with endoplasmic reticulum stress and the unfolded protein response. We discuss whether OH-PBDE bioaccumulation could result in impairment of the adrenocortical secretory function.
Cytotoxicity and gene expression profiling of two hydroxylated polybrominated diphenyl ethers in human H295R adrenocortical carcinoma cells.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Activation of the aryl hydrocarbon receptor dampens the severity of inflammatory skin conditions.
Sex, Age, Specimen part, Treatment, Subject
View SamplesEnvironmental stimuli are known to contribute to psoriasis pathogenesis and that of other autoimmune diseases, but the mechanism is unknown. Here we show that the aryl hydrocarbon receptor (AhR), a transcription factor that senses environmental stimuli, modulates pathology in psoriasis. AhR-activating ligands reduced inflammation in the lesional skin of psoriasis patients, whereas AhR antagonists upregulated inflammation. Similarly, AhR signaling via the endogenous FICZ ligand reduced the inflammatory response in the imiquimod-induced model of psoriasis and AhR deficient mice exhibited a substantial exacerbation of the disease, compared to AhR sufficient controls. Non-haematopoietic cells, in particular keratinocytes, were responsible for this hyper-inflammatory response, which involved increased reactivity to IL-1beta and upregulation of AP-1 family members of transcription factors. Thus, our data suggest a critical role for AhR in the regulation of inflammatory responses and open the possibility for novel therapeutic strategies in chronic inflammatory disorders. Overall design: Total RNA obtained from skin explants taken from psoriatic patients or healthy donors cultured in the presence of AhR agonist or antagonist
Activation of the aryl hydrocarbon receptor dampens the severity of inflammatory skin conditions.
No sample metadata fields
View SamplesEnvironmental stimuli are known to contribute to psoriasis pathogenesis and that of other autoimmune diseases, but the mechanism is unknown. Here we show that the aryl hydrocarbon receptor (AhR), a transcription factor that senses environmental stimuli, modulates pathology in psoriasis. AhR-activating ligands reduced inflammation in the lesional skin of psoriasis patients, whereas AhR antagonists upregulated inflammation. Similarly, AhR signaling via the endogenous FICZ ligand reduced the inflammatory response in the imiquimod-induced model of psoriasis and AhR deficient mice exhibited a substantial exacerbation of the disease, compared to AhR sufficient controls. Non-haematopoietic cells, in particular keratinocytes, were responsible for this hyper-inflammatory response, which involved increased reactivity to IL-1beta and upregulation of AP-1 family members of transcription factors. Thus, our data suggest a critical role for AhR in the regulation of inflammatory responses and open the possibility for novel therapeutic strategies in chronic inflammatory disorders.
Activation of the aryl hydrocarbon receptor dampens the severity of inflammatory skin conditions.
Specimen part
View SamplesIn this study, we have uncovered novel proteolytic processing of the histone H3 tail in senescence models in primary fibroblasts and melanocytes. Cleavage of H3 tail occurs at two distinct residues and is mediated by Cathepsin L. We show that variant H3.3 is preferentially cleaved, and that cleaved histones are associated with chromatin and incorporated into nucleosomes. We also found that the histone chaperone ASF1a is required for chromatin incorporation of the cleaved histone species. Further, we show that overexpression of cleaved H3.3 induces a senescence program in fibroblasts in the absensence of oncogenic signaling. Overall design: For the RNA-seq studies, growing IMR90 fibroblasts were compared to cells induced to senesce via oncogene activation or cleaved H3.3 overexpression. Growing controls consist of IMR90 cells infected with empty retroviral construct pBabe and grown under normal conditions for 13 days prior to RNA isolation. For oncogene-induced senescence samples, IMR90s carrying a tamoxifen-inducible H-RasV12 retroviral construct were induced to senesce by addition of 10nM tamoxifen to the media for 8 days. Finally, IMR90s were infected with a retroviral construct expressing the cleaved form of H3.3 with a C-terminal Flag tag. RNA samples form this group were isolated at days 3 (early) and 13 (late) post-infection. In all cases, total RNA samples were isolated using RNeasy kit (Qiagen) and prepared at the Icahn School of Medicine at Mount Sinai Genomics Core Facility for poly A library construction and sequencing on IlluminaHiSeq 2500.
Histone H3.3 and its proteolytically processed form drive a cellular senescence programme.
No sample metadata fields
View SamplesLRAT knockout mice on vitamin A sufficient or deficient diets were compared to age-matched wildtype mice on a vitamin A sufficient diet
Effects of vitamin A deficiency in the postnatal mouse heart: role of hepatic retinoid stores.
Sex, Specimen part
View SamplesLRAT knockout mice on vitamin A sufficient or deficient diets were compared to age and gender matched wildtype mice on a vitamin A sufficient diet
Effects of vitamin A deficiency in the postnatal mouse heart: role of hepatic retinoid stores.
Sex, Specimen part
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