Objective: the objective of this work was to determine different gene expression patterns in small bowel grafts biopsies with “minimal changes” histology that could identify patients with high rejection risk Methods: 24 samples (17 stable and 7 non stable grafts) from 8 adult patients with small bowel transplantation were included for RNA-Sequencing.Total RNA extracted from intestinal biopsies was used with the TruSeq RNA Sample Preparation v2 Kit to construct index-tagged cDNA libraries. Libraries were sequenced on the Genome Analyzer IIx following the standard RNA sequencing protocol with the TruSeq SBS Kit v5. Fastq files containing reads for each library were extracted and demultiplexed using Casava v1.8.2 pipeline. Sequencing adapter contaminations were removed from reads using Cutadapt software v1.6 and the resulting reads were aligned to the reference human genome (Ensembl gene-build GRCh37.75) using TopHat2 v2.0.13. Gene expression values were calculated as counts using HTSeq v0.6.1. Only genes with at least 1 count per million in all samples were considered for statistical analysis. Data were then normalized and differential expression tested using the R Bioconductor package edgeR. We selected all biopsies from 4 of the patients (18 biopsies, 11 stable and 7 non stable) as the discovery set. The other 6 biopsies from 4 patients (all stable) were used as the test set. Differences in the discovery set were tested by generalized linear model analysis,and results were considered significant when the Benjamini-Hochberg adjusted p-value was < 0,05. Results: We obtained 816 differentially expressed genes (DEGs) between stable and non stable biopsies in the discovery set: 369 upregulated and 447 downregulated in the non stable group. The classification and prediction with the Nearest Shrunken Centroids method identified 5 genes (ADH1C, CYP4F2, PDZK1, SLC39A4 and OPTN) from the 816 DEGs that could classify both groups with an error rate of 11% and classified correctly all samples from the test set. These results were confirmed by Supoprted Vector Machine (SVM), bagSVM and Random Forest methods, showing high accuracy, sensitivity and specificity. Conclusions: We identified 5 genes from the DEGs as possible biomarkers to classify patients with normal histology that could be however in a higher risk of rejection. In this way, gene expression assays are powerful tools with high sensitivity that allow more accurate diagnosis. Overall design: The study included 24 samples from 8 adult patients with small bowel transplantation. Samples correspond to RNA extracted from intestinal biopsies obtained at different post-transplantation time. All biopsies have an histological diagnosis of "minimal changes" and they were classified in two groups according their immunological stability (stable and non stable). Stable group comprised biopsies of patients that never rejected and biopsies obtained at least 15 days after rejection if no other rejection episode occurred in at least the next six months. Non stable group included biopsies obtained between rejection episodes (separated less than six months) and also those biopsies collected within the 15 days before the first rejection episode.
5-gene differential expression predicts stability of human intestinal allografts.
No sample metadata fields
View SamplesWe performed a transcriptomic analysis of Pi starvation responses in Arabidopsis thaliana (Columbia-0) wild type plants under phosphate starvation stress and in plants with altered PHR1(-like) activity, comparing mutants of phr1 and phr1-phl1 grown in phosphate-lacking medium. Results show the central role of PHR1 and functionally redundant members of its family in the control of transcriptional responses to Pi starvation.
A central regulatory system largely controls transcriptional activation and repression responses to phosphate starvation in Arabidopsis.
Specimen part
View SamplesWe performed a transcriptomic analysis of Pi starvation responses in Arabidopsis thaliana (Columbia-0) phr1 mutant plants expressing PHR1 in presence of cicloheximide, that inhibit protein translation, thus preventing any effect of PHR1 on the expression of indirect targets. Results show the primary target genes of PHR1 in the responses to Pi starvation.
A central regulatory system largely controls transcriptional activation and repression responses to phosphate starvation in Arabidopsis.
No sample metadata fields
View SamplesThe objective is to generate a robust and validated predictor profile for chemotherapy response in patients with mCRC using microarray gene expression profiles of primary colorectal cancer tissue.
Gene expression profile predictive of response to chemotherapy in metastatic colorectal cancer.
Disease, Disease stage
View SamplesWe performed a transcriptomic analysis of Pi-starvation and recovery after resupplying Pi in Arabidopsis thaliana (Columbia-0) wild type plants and double mutant spx1,spx2. Results show that SPX1 is a Pi-dependent inhibitor of the transcription factor PHR1, a central regulatory protein in the control of transcriptional responses to Pi starvation.
SPX1 is a phosphate-dependent inhibitor of Phosphate Starvation Response 1 in Arabidopsis.
Age, Specimen part
View SamplesWe describe a new mutant allele of the ACTIN2 gene with enhanced actin dynamics, displaying a broad array of twisting and bending phenotypes that resemble BR-treated plants. Moreover, auxin transcriptional regulation is enhanced on the mutant background, supporting the idea that shaping actin filaments is sufficient to modulate BR-mediated auxin responsiveness. The actin cytoskeleton thus functions as a scaffold for integration of auxin and BR signaling pathways.
Role of actin cytoskeleton in brassinosteroid signaling and in its integration with the auxin response in plants.
No sample metadata fields
View SamplesStress constantly challenges plant adaptation to the environment. Of all stress types, arsenic was a major threat during the early evolution of plants. The most prevalent chemical form of arsenic is arsenate, whose similarity to phosphate renders it easily incorporated into cells via the phosphate transporters. Here we found that arsenate stress provokes a notable transposon burst in plants, in coordination with arsenate/phosphate transporter repression, which immediately restricts arsenate uptake. This repression was accompanied by delocalization of the phosphate transporter from the plasma membrane. When arsenate was removed, the system rapidly restored transcriptional expression and membrane localization of the transporter. We identify WRKY6 as an arsenate-responsive transcription factor that mediates arsenate/phosphate transporter gene expression and restricts arsenate-induced transposon activation. Plants therefore have a dual WRKY-dependent signaling mechanism that modulates arsenate uptake and transposon expression, providing a coordinated strategy for arsenate tolerance and transposon gene silencing.
WRKY6 transcription factor restricts arsenate uptake and transposon activation in Arabidopsis.
Time
View SamplesThis SuperSeries is composed of the SubSeries listed below.
A novel chordoma xenograft allows in vivo drug testing and reveals the importance of NF-κB signaling in chordoma biology.
Specimen part
View SamplesChordoma is a rare primary bone malignancy that arises in the skull base, spine and sacrum and originates from remnants of the notochord. These tumors are typically resistant to conventional chemotherapy, and to date there are no FDA-approved agents to treat chordoma. The lack of in vivo models of chordoma has impeded the development of new therapies for this tumor. Primary tumor from a sacral chordoma was xenografted into NOD/SCID/IL-2R -null mice. The xenograft is serially transplantable and was characterized by both gene expression analysis and whole genome SNP genotyping. The NIH Chemical Genomics Center performed high-throughput screening of 2,816 compounds using two established chordoma cell lines, U-CH1 and U-CH2B. The screen yielded several compounds that showed activity and two, sunitinib and bortezomib, were tested in the xenograft. Both agents slowed the growth of the xenograft tumor. Sensitivity to an inhibitor of IB, as well as inhibition of an NF-B gene expression signature demonstrated the importance of NF-B signaling for chordoma growth. This serially transplantable chordoma xenograft is thus a practical model to study chordomas and perform in vivo preclinical drug testing.
A novel chordoma xenograft allows in vivo drug testing and reveals the importance of NF-κB signaling in chordoma biology.
Specimen part
View SampleshCLE/C14orf166/RTRAF, DDX1 and HSPC117 are components of cytoplasmic mRNA-transporting granules kinesin-associated in dendrites. They have also been found in cytoplasmic ribosome-containing RNA granules that transport specific mRNAs halted for translation until specific neuronal signals renders them accessible to the translation machinery. hCLE associates to DDX1, HSPC117 and FAM98B in HEK293T cells and all four proteins bind to cap analog-containing resins. Competition and elution experiments indicate that binding of hCLE complex to cap resins is independent of eIF4E; the cap-binding factor needed for translation. Purified hCLE free of its associated proteins binds cap with low affinity suggesting that its interacting proteins modulate its cap association. hCLE silencing reduces hCLE accumulation and that of its interacting proteins and decreases mRNA translation. hCLE-associated RNAs have been isolated and sequenced; RNAs involved in mRNA translation are specifically associated. The data suggest a positive role of hCLE complex modulating mRNA translation. Overall design: Standard RNA-seq protocol was applied for comparing two sample types (HEK293T cells transfected with hCLE-TAP plasmid or empty TAP) with two biological replicates each. More than 20 million single-end, strand-specific 50 nt reads were generated for each sample.
hCLE/RTRAF-HSPC117-DDX1-FAM98B: A New Cap-Binding Complex That Activates mRNA Translation.
Cell line, Subject
View Samples