BACKGROUND: We have previously reported gene expression changes in the bronchial airway epithelium of active chronic smokers. In this study, we investigate the effects of Acute Smoke Exposure (ASE) from cigarettes on airway epithelial gene expression. METHODS: Bronchial airway epithelial cell brushings were collected via fiberoptic bronchoscopy from 63 individuals without recent exposure to cigarette smoke (> 2 days), at baseline and at 24 hours after smoking three cigarettes. RNA from these samples was profiled on Affymetrix Human Gene 1.0 ST microarrays. Differential gene expression was assessed using linear modeling and compared to previous smoking-related gene-expression signatures using Gene Set Enrichment Analysis (GSEA). RESULTS: We identified 91 genes differentially expressed 24-hours after exposure to three cigarettes (FDR < 0.25). ASE induces genes involved in xenobiotic metabolism, oxidative stress, and inflammation; and represses genes involved in cilium morphogenesis, and cell cycle. Genes induced by in vivo ASE are concordantly altered by ASE in vitro. While many genes altered by ASE are altered similarly in the airway of chronic smokers, metallothionein genes were induced by ASE and suppressed among chronic smokers. Metallothioneins were also suppressed in the bronchial airway of current and former chronic smokers with lung cancer relative to those with benign disease. CONCLUSIONS: Acute exposure to as little as three cigarettes alters gene-expression in bronchial airway epithelium in a manner that largely resembles the changes seen in chronic active smokers. The difference in the short-term and long-term effects of smoking on metallothionein expression and its relationship to lung cancer requires further study given these enzymes role in responding to oxidative stress.
Impact of acute exposure to cigarette smoke on airway gene expression.
Sex
View SamplesDuring development of the central nervous system (CNS), cycling uncommitted progenitor cells give rise to a variety of distinct neuronal and glial cell types. As these different cell types are born, they progress from newly specified cells to fully differentiated neurons and glia. In order to define the developmental processes of individual cell types, single cell expression profiling was carried out on developing ganglion and amacrine cells of the murine retina. Individual cells from multiple developmental stages were isolated and profiled on Affymetrix oligonucleotide arrays. These experiments have yielded an expanded view of the processes underway in developing retinal ganglion and amacrine cells, as well as several hundred new marker genes for these cell types. In addition, this study has allowed for the definition of some of the molecular heterogeneity both between developing ganglion and amacrine cells and among subclasses of each cell type.
Molecular heterogeneity of developing retinal ganglion and amacrine cells revealed through single cell gene expression profiling.
Specimen part
View SamplesLymphangioleiomyomatosis (LAM) is characterized by cystic lung destruction caused by smooth, muscle-like LAM cells which have mutations in the tumor suppressor genes Tuberous Sclerosis Complex (TSC) 1 or 2, and the capacity to metastasize. Since chemokines and their receptors function in chemotaxis of metastatic cells, we hypothesized that LAM cells may be recruited by chemokine(s) in the lung. Quantification of 25 chemokines in bronchoalveolar lavage fluid from LAM patients and healthy volunteers revealed that concentrations of MCP-1/CCL2, GROa/CXCL1 and ENA-78/CXCL5 were significantly higher in samples from LAM patients than healthy volunteers. In this transcript analysis, expression of chemokine and chemokine receptor mRNA in LAM cells differed from those in melanoma and smooth muscle cells. Subsequent immunohistochemistry of lung sections from 30 LAM patients confirmed protein expression of chemokines and these receptors varied among LAM patient and differed from that seen in breast cancer and melanoma cells. . In vitro, MCP-1/CCL2 induced selective migration of cells showing loss of heterozygosity of TSC2 from a heterogeneous populations of cells grown from explanted LAM lungs. In addition, the frequencies of single-nucleotide polymorphisms in the MCP-1 gene promoter region differed significantly in LAM patients and healthy volunteers (p=0.018), and one polymorphism was associated significantly more frequently with the decline of lung function. These observations are consistent with the notion that chemokines such as MCP-1 may serve to specify site of LAM cell metastasis.
Chemokine-enhanced chemotaxis of lymphangioleiomyomatosis cells with mutations in the tumor suppressor TSC2 gene.
Sex, Specimen part
View SamplesPatients with tuberous sclerosis complex (TSC) develop hamartomas containing biallelic inactivating mutations in either TSC1 or TSC2, resulting in mammalian target of rapamycin (mTOR) activation. Hamartomas overgrow epithelial and mesenchymal cells in TSC skin. The pathogenetic mechanisms for these changes had not been investigated, and the existence or location of cells with biallelic mutations (two-hit cells) that resulted in mTOR activation was unclear. We compared TSC skin hamartomas (facial angiofibromas and periungual fibromas) to normal-appearing skin of the same patient, and observed more proliferation and mTOR activation in hamartoma epidermis. Two-hit cells were not detected in the epidermis. Fibroblast-like cells in the dermis, however, exhibited allelic deletion of TSC2, in both touch preparations of fresh tumor samples and cells grown from TSC skin tumors, suggesting that increased epidermal proliferation and mTOR activation were not caused by second-hit mutations in the keratinocytes but by mesenchymal-epithelial interactions. Gene expression arrays, used to identify potential paracrine factors released by mesenchymal cells, revealed more epiregulin mRNA in fibroblast-like angiofibroma and periungual fibroma cells than in fibroblasts from normal-appearing skin of the same patient. Elevation of epiregulin mRNA was confirmed using real-time PCR, and increased amounts of epiregulin protein were demonstrated using immunoprecipitation and ELISA. Epiregulin stimulated keratinocyte proliferation and phosphorylation of ribosomal protein S6 in vitro. These results suggest that hamartomatous TSC skin tumors are induced by paracrine factors released by two-hit cells in the dermis, and that proliferation with mTOR activation of the overlying epidermis is an effect of epiregulin.
Mesenchymal-epithelial interactions involving epiregulin in tuberous sclerosis complex hamartomas.
Sex, Specimen part
View SamplesDetermination of differential expression of genes in the thyroid of pendrin (Slc26a4) heterozygous and knockout mice at a time point corresponding to maximal thyroid gland activity, postnatal day 15 (P15).
Developmental delays consistent with cochlear hypothyroidism contribute to failure to develop hearing in mice lacking Slc26a4/pendrin expression.
No sample metadata fields
View SamplesMesenchyme-derived cells in the human airway wall including airway smooth muscle cells, fibroblasts and myofibroblasts are known to play important roles in airway remodeling. The lack of specific phenotypic markers makes it difficult to define these cell populations in primary cultures. The objectives of this study were to evaluate reported markers and to identify novel markers to define these cell types.
Can lineage-specific markers be identified to characterize mesenchyme-derived cell populations in the human airways?
Specimen part
View SamplesDetermination of the genes regulated by ERRalpha nuclear receptor in MDA-MB231 cells Overall design: MDA-MB231 cells were inactivated for ERRalpha using siRNA. Three different siRNAs were used (siE1, siE2, siE3). Cells treated with a control siRNA (siC samples) were used for comparison. Duplicate samples were analyzed. Transcriptomic analysis was performed by RNA-Seq
ERRα induces H3K9 demethylation by LSD1 to promote cell invasion.
Cell line, Subject
View SamplesDetermination of the genes regulated by LSD1 in MDA-MB231 cells Overall design: MDA-MB231 cells were inactivated for LSD1 using siRNA. Two different siRNAs were used (siL1, siL2). Cells treated with a control siRNA (siC samples) were used for comparison. Duplicate samples were analyzed. Transcriptomic analysis was performed by RNA-Seq
ERRα induces H3K9 demethylation by LSD1 to promote cell invasion.
No sample metadata fields
View SamplesWe report a novel technique, Affinity-seq, that for the first time identifies both the genome-wide binding sites of DNA-binding proteins and quantitates their relative affinities. We have applied this in vitro technique to PRDM9, the zinc-finger protein that activates genetic recombination, obtaining new information on the regulation of hotspots, whose locations and activities determine the recombination landscape. We identified 31,770 binding sites in the mouse genome for the PRDM9Dom2 variant. Comparing these results with hotspot usage in vivo, we find that less than half of potential PRDM9 binding sites are utilized in vivo. We show that hotspot usage is increased in actively transcribed genes and decreased in genomic regions containing H3K9me2/3 histone marks or bound to the nuclear lamina. These results show that a major factor determining whether a binding site will become an active hotspot and what its activity will be are constraints imposed by prior chromatin modifications on the ability of PRDM9 to bind to DNA in vivo. These constraints lead to the presence of long genomic regions depleted of recombination. Overall design: The terminal zinc finger domain of PRDM9Dom2 (PRDM9?ZnF1Dom2, 412–847 aa), the allele present in C57BL/6J (B6) mice was cloned and tagged with 6His-HALO and then expressed in E. coli. DNA sheared to 180–200 bp is provided in considerable excess to provide competition between DNA binding sites. Following binding, DNA–protein complexes are then isolated on streptavidin beads and the DNA extracted for deep sequencing. Two replicate Affinity-seq samples were sequenced at 100-bp reads using the Illumina HiSeq 2500. Alignments to the mm9 mouse genome were obtained utilizing BWA v1.2.3 with default parameters and reads which failed to align to unique positions in the genome were discarded. Peaks were called individually for the two replicates with MACS2 at a p value threshold of 0.01 utilizing a control dataset obtained by sequencing the input DNA and subsequently compared, leading ultimately to combining the two replicates for definitive analysis.
Affinity-seq detects genome-wide PRDM9 binding sites and reveals the impact of prior chromatin modifications on mammalian recombination hotspot usage.
No sample metadata fields
View SamplesCurcumin is a potent anti-inflammatory compound capable of preventing chemically induced colitis in mice.
Protective effects of dietary curcumin in mouse model of chemically induced colitis are strain dependent.
Treatment
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