Our studies identify a mechanism of signaling crosstalk during valve morphogenesis that sheds light on the origin of congenital heart defects associated with reduced Notch function. Overall design: Aortic and pulmonary cardiac valves were isolated by laser microdissection from WT and Jag1flox;Nkx2.5-Cre mouse embryos at stage E14.5, and their expression profile characterized by RNA-Seq.
Sequential Ligand-Dependent Notch Signaling Activation Regulates Valve Primordium Formation and Morphogenesis.
Specimen part, Subject
View SamplesAlthough mechanisms of acquired resistance of EGFR mutant non-small cell lung cancers to EGFR inhibitors have been identified, little is known about how resistant clones evolve during drug therapy. Here, we observe that acquired resistance caused by the T790M gatekeeper mutation can occur either by selection of pre-existing T790M clones or via genetic evolution of initially T790M-negative drug tolerant cells. The path to resistance impacts the biology of the resistant clone, as those that evolved from drug tolerant cells had a diminished apoptotic response to third generation EGFR inhibitors that target T790M EGFR; treatment with navitoclax, an inhibitor of BCL-XL and BCL-2 restored sensitivity. We corroborated these findings using cultures derived directly from EGFR inhibitor-resistant patient tumors. These findings provide evidence that clinically relevant drug resistant cancer cells can both pre-exist and evolve from drug tolerant cells, and point to therapeutic opportunities to prevent or overcome resistance in the clinic. Overall design: Examination of mRNA levels of PC9 parental, drug-tolerant, PC9-GR2 and PC9-GR3 cells after treatment with vehicle, gefitinib or WZ4002 for 24 hours.
Tumor cells can follow distinct evolutionary paths to become resistant to epidermal growth factor receptor inhibition.
No sample metadata fields
View SamplesThe tumoral clone of Waldenstrms macroglobulinemia (WM) shows a wide morphological heterogeneity which ranges from B-lymphocytes (BL) to plasma cells (PC). By means of genome-wide expression profiling we have been able to identify genes exclusively deregulated in BL and PC from WM, but with a similar expression pattern in their corresponding cell-counterparts from CLL and MM, as well as normal individuals. The differentially expressed genes have important functions in B-cell differentiation and oncogenesis. Thus, two of the genes down-regulated in WM-BL were IL4R, which plays a relevant role in CLL B cell survival, and BACH2 that participates in the development of class-switched PC. Interestingly, one of the up-regulated genes in WM-BL was IL6. A set of 4 genes was able to discriminate clonal B-lymphocytes from WM and CLL: LEF1 (WNT/catenin pathway), MARCKS, ATXN1 and FMOD. We also found deregulation of genes involved in plasma cell differentiation such as PAX5 which was overexpressed in WM-PC, and IRF4 and BLIMP1 which were underexpressed. In addition, three of the target genes activated by PAX5 -CD79, BLNK and SYK- were up-regulated in WM-PC. In summary, these results indicate that both PC and BL from WM are genetically different from the MM and CLL cell-counterpart.
Gene expression profiling of B lymphocytes and plasma cells from Waldenström's macroglobulinemia: comparison with expression patterns of the same cell counterparts from chronic lymphocytic leukemia, multiple myeloma and normal individuals.
No sample metadata fields
View SamplesTo understand which genes acts downstream AtHB1 affecting hypocotyl growth in Arabidopsis thaliana, we performed transcriptional profiles of 4-day-old seedlings grown in a short-day regime comparing wild-type with athb1-1 mutant plants. These results show that some of the AtHB1-regulated genes modulate cell elongation, particularly cell wall composition and elongation, or encode proteins that serve as a source of carbon, nitrogen, and sulfur for early seedling growth. Overall design: RNA-Seq data for 4-day-old wild-type (Col-0) and athb1-1 mutant seedlings grown under short-day conditions. Biological triplicates were performed for each genotype analyzed.
Arabidopsis thaliana HomeoBox 1 (AtHB1), a Homedomain-Leucine Zipper I (HD-Zip I) transcription factor, is regulated by PHYTOCHROME-INTERACTING FACTOR 1 to promote hypocotyl elongation.
Subject
View SamplesTo understand the fruit changes and mechanisms involved in the compatible grapevine-virus interaction, we analyzed the berry transcriptome in two stages of development (veraison and ripening) in the red wine cultivar Cabernet Sauvignon infected with Grapevine leaf-roll-associated virus-3 (GLRaV-3). Analysis of global gene expression patterns indicate incomplete berry maturation in infected berries as compared to uninfected fruit suggesting viral infection interrupts the normal berry maturation process.
Compatible GLRaV-3 viral infections affect berry ripening decreasing sugar accumulation and anthocyanin biosynthesis in Vitis vinifera.
Age, Specimen part
View SamplesBoron is an essential micronutrient for plants and is taken up in the form of boric acid (BA). Despite this, a high BA concentration is toxic for the plants, inhibiting root growth and is thus a significant problem in semi-arid areas in the world. In this work, we report the molecular basis for the inhibition of root growth caused by boron. We used microarrays to detail the global gene expression underlying boron toxicity in roots.
A molecular framework for the inhibition of Arabidopsis root growth in response to boron toxicity.
Specimen part, Treatment
View SamplesWe demonstrate that the versatile environmental bacterium Pseudomonas aeruginosa adapts a virulence phenotype after serial passage in Galleria mellonella as an invertebrate model host. The virulence phenotype was not linked to the acquisition of genetic variations and was sustained for several generations, despite cultivation of the ex vivo virulence-adapted P. aeruginosa cells under non-inducing rich medium conditions. Transcriptional reprogramming seemed to be induced by a host-specific food source as reprogramming was also observed upon cultivation of P. aeruginosa in medium supplemented with polyunsaturated long-chain fatty acids. Methods : mRNA profiles were generated for Pseudomonas aerugionsa samples derived from LB-cultures grown to an OD600 =2. The removal of ribosomal RNA was performed using the Ribo-Zero Bacteria Kit (Illumina) and cDNA libraries were generated with the ScriptSeq v2 Kit (Illumina) . The samples were sequenced in single end mode on an Illumina HiSeq 2500 device and mRNA reads were trimmed and mapped to the NC_008463.1 (PA14) reference genome from NCBI using Stampy pipeline with defaut settings. Overall design: Isolate CH2658 was subjected to in vivo and in vitro evolution experiments in this study. This isolate was obtained from the lab of G. Gastmeier, Charite Berlin, Germany. The in vivo passages (using G. mellonella) are named CH2658 I-IV corresponding to passages 1 4. The last passage CH2658 IV corresponds to the “evolved strain” and was passaged in LB (four days, two passages a day) to generate revertants which are referred to as CH2658 Rev1-4 corresponding to samples from day1-4. The last passage CH2658 Rev4 is called “revertant”. Additionally, the clinical isolate was passaged under in vitro conditions in the presence of linolenic acid (Roth) with (CH2658 Lil+P) and without paraffin (CH2658 Lil). As controls, CH2658 was passaged in LB (CH2658 LB) and in LB supplemented with paraffin (CH2658 LB+P). The in vitro passage experiment was conducted for four days and two passages a day.
Establishment of an induced memory response in Pseudomonas aeruginosa during infection of a eukaryotic host.
Subject
View SamplesBackground: Global DNA methylation contributes to genomic integrity by supressing repeat associated transposition events. Several chromatin factors are required in addition to DNA methyltransferases to maintain DNA methylation at intergenic and satellite repeats. Embryos lacking Lsh, a member of the SNF2 superfamily of chromatin helicases, are hypomethylated. The interaction of Lsh with the de novo methyltransferase, Dnmt3b, facilitates the deposition of DNA methylation at stem cell genes. We wished to determine if a similar targeting mechanism operates to maintain DNA methylation at repetitive sequences. Results: We used HELP-seq to map genome wide DNA methylation patterns in Lsh-/- and Dnmt3b-/- somatic cells. DNA methylation is predominantly lost from specific genomic repeats in Lsh-/- cells: LTR-retrotransposons, LINE-1 repeats and mouse satellites. RNA-seq experiments demonstrate that specific IAP (Intracisternal A-type particle) LTRs and satellites, but not LINE-1 elements, are aberrantly transcribed inLsh-/- cells. LTR hypomethylation in Dnmt3b-/- cells is moderate and hypomethylated repetitive elements (IAP, LINE-1 and satellite) are silent. Chromatin immunoprecipitation (ChIP) indicates that repressed LINE-1 elements gain H3K4me3, but H3K9me3 levels are unaltered in Lsh-/- cells, indicating that DNA hypomethylation alone is not permissive for their transcriptional activation. Mis-expressed IAPs and satellites lose H3K9me3 and gain H3K4me3 in Lsh-/- cells. Conclusions: Our study emphasizes that regulation of repetitive elements by DNA methylation is selective and context dependent. We propose a model where Lsh is specifically required at a precise developmental window to target de novo methylation to repeat sequences, which is subsequently maintained by Dnmt1 in somatic cells to enforce repeat silencing thus contributing to genomic integrity. Overall design: Two pairs of RNA samples compared: WT and Lsh-/- RNA isolations from tail-tip fibroblasts; WT and Lsh-/- RNA isolations from E13.5 mouse embryos.
Lsh regulates LTR retrotransposon repression independently of Dnmt3b function.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Gene expression effects of glucocorticoid and mineralocorticoid receptor agonists and antagonists on normal human skeletal muscle.
Sex, Specimen part
View SamplesTo define the direct gene expression changes in normal human skeletal muscle with mineralocorticoid and glucocorticoid receptor agonist and antagonist treatment.
Gene expression effects of glucocorticoid and mineralocorticoid receptor agonists and antagonists on normal human skeletal muscle.
Sex, Specimen part
View Samples