A key question in developmental biology is how cells exchange positional information for proper patterning during organ development. In plant roots the radial tissue organization is highly conserved with a central vascular cylinder in which two water conducting cell types, protoxylem and metaxylem, are patterned centripetally. We show that this patterning occurs through crosstalk between the vascular cylinder and the surrounding endodermis mediated by cell-to-cell movement of a transcription factor in one direction and microRNAs in the other. SHORT ROOT, produced in the vascular cylinder, moves into the endodermis to activate SCARECROW. Together these transcription factors activate MIR165a and 166b. Endodermally produced miR165/6 then acts to degrade its target mRNAs encoding class III homeodomain-leucine zipper transcription factors in the endodermis and stele periphery. The resulting differential distribution of target mRNA in the vascular cylinder determines xylem cell types in a dosage dependent manner.
Cell signalling by microRNA165/6 directs gene dose-dependent root cell fate.
Age, Specimen part
View SamplesTriple-negative (TN) breast cancers need to be refined in order to identify therapeutic subgroups of patients.
Gene-expression molecular subtyping of triple-negative breast cancer tumours: importance of immune response.
Disease
View SamplesMutations in PROP1 are the most common cause of hypopituitarism in humans; therefore, unraveling its mechanism of action is highly relevant from a therapeutic perspective. Our current understanding of the role of PROP1 in the pituitary gland is limited to the regulation of pituitary transcription factors Hesx1 and Pit1. To elucidate the comprehensive PROP1-dependent gene regulatory network, we conducted genome wide analysis of PROP1 DNA binding and effects on gene expression in mutant tissues, isolated stem cells and engineered cell lines. We determined that PROP1 is essential for maintaining proliferation of stem cells and stimulating them to undergo an epithelial to mesenchymal transition-like process necessary for cell migration and differentiation. Genomic profiling reveals that PROP1 binds to and represses claudin 23, characteristic of epithelial cells, and it activates EMT inducer genes: Zeb2, Notch2 and Gli2. Our findings identify PROP1 as a central transcriptional component of pituitary stem cell differentiation. Overall design: Pituitary Colony forming cells mRNA of 13-day old wild type (Prop1 +/+), Prop1 mutants (Prop1df/df), wild type (Pit1+/+) and Pit1 mutants (Pit1 dw/dw) mice were generated by deep sequencing, in triplicates.
PROP1 triggers epithelial-mesenchymal transition-like process in pituitary stem cells.
Specimen part, Cell line, Subject
View SamplesDue to its low level of nephrotoxicity and capacity to harness tolerogenic pathways, sirolimus (SRL) has been proposed as an alternative to calcineurin inhibitors in transplantation. The exact mechanisms underlying its unique immunosuppressive profile in humans, however, are still not well understood. In the current study we aimed to depict the in vivo effects of SRL in comparison with cyclosporin A (CSA) by employing gene expression profiling and multiparameter flow cytometry on blood cells collected from stable kidney recipients under immunosuppressant monotherapy. SRL recipients displayed an increased frequency of CD4+CD25highFoxp3+ T cells. However, this was accompanied by an increased number of effector memory T cells and by enrichment in NFkB-related pro-inflammatory expression pathways and monocyte and NK cell lineage-specific transcripts. Furthermore, measurement of a transcriptional signature characteristic of operationally tolerant kidney recipients failed to detect differences between SRL and CSA treated recipients. In conclusion, we show here that the blood transcriptional profile induced by SRL monotherapy in vivo does not resemble that of operationally tolerant recipients and is dominated by innate immune cells and NFkB-related pro-inflammatory events. These data provide novel insights on the complex effects of SLR on the immune system in clinical transplantation.
Comparative transcriptional and phenotypic peripheral blood analysis of kidney recipients under cyclosporin A or sirolimus monotherapy.
Specimen part, Disease
View SamplesIn this study, we employed massively parallel sequencing technology to identify miRNAs expressed in B-cells from Ashkenazi Jewish centenarians, i.e., those living to a hundred and a human model of exceptional longevity, and younger controls without a family history of longevity. With data from 26.7 million reads comprising 9.4x108 bp from 3 centenarian and 3 control individuals, we discovered a total of 276 known miRNAs and 8 unknown miRNAs ranging several orders of magnitude in expression levels. A total of 22 miRNAs were found to be significantly upregulated, with only 2 miRNAs downregulated, in centenarians as compared to controls. Overall design: Examination of miRNA profile of two different ages
Comprehensive microRNA profiling in B-cells of human centenarians by massively parallel sequencing.
Specimen part, Race, Subject
View SamplesThe Long Evans/orl (LE/orl) rat is an animal model of inherited undescended testis (UDT). To explore genetic mechanisms of UDT, we studied differential gene expression in LE/orl and LE wild type (LE/wt) fetal gubernaculum and testis.
Altered expression of muscle- and cytoskeleton-related genes in a rat strain with inherited cryptorchidism.
Sex, Specimen part
View SamplesFetal spleens were collected at days 82 and 97 of gestation following maternal infection with BVDV on day 75 of gestation.
Attenuated lymphocyte activation leads to the development of immunotolerance in bovine fetuses persistently infected with bovine viral diarrhea virus†.
Sex, Specimen part
View SamplesNuclear lamin B1 constitutes one of the major structural proteins in the lamina mesh. We silenced the expression of lamin B1 by RNA interference in the colon cancer cell line DLD-1 and showed a dramatic redistribution of H3K27me3 from the periphery to a more homogeneous nuclear dispersion; in addition we observed an increased frequency of micronuclei and nuclear blebs. By 3D-FISH analyses, we demonstrate that the volume and surface of chromosome territories were significantly larger in LMNB1-depleted cells, suggesting that lamin B1 is required to maintain chromatin condensation in interphase nuclei. These changes led to a prolonged S-phase due to activation of Chk1 and telomere attrition. Finally, silencing of LMNB1 resulted in extensive changes in alternative splicing of multiple genes and in a higher number of enlarged nuclear speckles. Taken together, our results suggest a mechanistic role of the nuclear lamina in the organization of chromosome territories, maintenance of genome integrity and proper gene splicing.
Loss of lamin B1 results in prolongation of S phase and decondensation of chromosome territories.
Cell line
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Identification of novel long noncoding RNAs underlying vertebrate cardiovascular development.
Specimen part
View SamplesLong non-coding RNAs (lncRNAs) have emerged as critical regulators of gene expression and chromatin modifications, with important functions in development and disease. Here we sought to identify and functionally characterize lncRNAs critical for vascular vertebrate development with significant conservation across species. Genome-wide transcriptomic analyses during human vascular lineage specification enabled the identification of three conserved novel lncRNAs: TERMINATOR, ALIEN and PUNISHER that are specifically expressed in pluripotent stem cells, mesoderm and endothelial cells, respectively. Gene expression profiling, alongside RNA immunoprecipitation coupled to mass spectrometry, revealed a wide range of new molecular networks and protein interactors related to post-transcriptional modifications for all three lncRNAs. Functional experiments in zebrafish and murine embryos, as well as differentiating human cells, confirmed a developmental-stage specific role for each lncRNA during vertebrate development. The identification and functional characterization of these three novel non-coding provide a comprehensive transcriptomic roadmap and shed new light on the molecular mechanisms underlying human vascular development. Overall design: Time course RNA-Seq analysis H1 ESCs differentiated into endothelial cells
Identification of novel long noncoding RNAs underlying vertebrate cardiovascular development.
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