Progressive failure of insulin-producing beta cells is the central event leading to diabetes, yet the signalling networks controlling beta cell fate remain poorly understood. Here we show that SRp55, a splicing factor regulated by the diabetes susceptibility gene GLIS3, has a major role in maintaining function and survival of human beta cells. RNA-seq analysis revealed that SRp55 regulates the splicing of genes involved in cell survival and death, insulin secretion and JNK signalling. Specifically, SRp55-mediated splicing changes modulate the function of the pro-apoptotic proteins BIM and BAX, JNK signalling and endoplasmic reticulum stress, explaining why SRp55 depletion triggers beta cell apoptosis. Furthermore, SRp55 depletion inhibits beta cell mitochondrial function, explaining the observed decrease in insulin release. These data unveil a novel layer of regulation of human beta cell function and survival, namely alternative splicing modulated by key splicing regulators such as SRp55 that may crosstalk with candidate genes for diabetes. Overall design: Five independent preparations of EndoC-ßH1 cells exposed to control (siCTL) or SRp55 (siSR#2) siRNAs
SRp55 Regulates a Splicing Network That Controls Human Pancreatic β-Cell Function and Survival.
Treatment, Subject
View SamplesTranscription profiling by array of mouse male retinas to investigate IGF-I-induced chronic gliosis and retinal stress
Insulin-like growth factor I (IGF-I)-induced chronic gliosis and retinal stress lead to neurodegeneration in a mouse model of retinopathy.
Sex, Specimen part
View SamplesPancreatic beta-cell dysfunction and death are central in the pathogenesis of type 2 diabetes. Saturated fatty acids cause beta-cell failure and contribute to diabetes development in genetically predisposed individuals. Here we used RNA-sequencing to map transcripts expressed in five palmitate-treated human islet preparations, observing 1,325 modified genes. Palmitate induced fatty acid metabolism and endoplasmic reticulum (ER) stress. Functional studies identified novel mediators of adaptive ER stress signaling. Palmitate modified genes regulating ubiquitin and proteasome function, autophagy and apoptosis. Inhibition of autophagic flux and lysosome function contributed to lipotoxicity. Palmitate inhibited transcription factors controlling beta-cell phenotype including PAX4 and GATA6. 59 type 2 diabetes candidate genes were expressed in human islets, and 11 were modified by palmitate. Palmitate modified expression of 17 splicing factors and shifted alternative splicing of 3,525 transcripts. Ingenuity Pathway Analysis of modified transcripts and genes confirmed that top changed functions related to cell death. DAVID analysis of transcription binding sites in palmitate-modified transcripts revealed a role for PAX4, GATA and the ER stress response regulators XBP1 and ATF6. This human islet transcriptome study identified novel mechanisms of palmitate-induced beta-cell dysfunction and death. The data point to crosstalk between metabolic stress and candidate genes at the beta-cell level. Overall design: 5 human islet of Langerhans preparations examined under 2 conditions (control and palmitate treatment)
RNA sequencing identifies dysregulation of the human pancreatic islet transcriptome by the saturated fatty acid palmitate.
No sample metadata fields
View SamplesDouble-stranded RNA-binding proteins are key elements in the intracellular localization of mRNA and its local translation. Staufen is a double-stranded RNA binding protein involved in the localised translation of specific mRNAs during Drosophila early development and neuronal cell fate. The human homologue Staufen1 forms RNA-containing complexes that include proteins involved in translation and motor proteins to allow their movement within the cell, but the mechanism underlying translation repression in these complexes is poorly understood. Here we show that human Staufen1-containing complexes contain essential elements of the gene silencing apparatus, like Ago1-3 proteins, and we describe a set of miRNAs specifically associated to complexes containing human Staufen1. Among these, miR124 stands out as particularly relevant because it appears enriched in human Staufen1 complexes and is over-expressed upon differentiation of human neuroblastoma cells in vitro. In agreement with these findings, we show that expression of human Staufen1 is essential for proper dendritic arborisation during neuroblastoma cell differentiation, yet it is not necessary for maintenance of the differentiated state, and suggest potential human Staufen1 mRNA targets involved in this process.
Human Staufen1 associates to miRNAs involved in neuronal cell differentiation and is required for correct dendritic formation.
Cell line
View SamplesThe transcriptional data from an integrative analysis of transcriptional and metabolic stress responses that provides a more complete understanding of the mechanisms by which genetic regulatory circuits mediate metabolic phenotype.
Linking high-resolution metabolic flux phenotypes and transcriptional regulation in yeast modulated by the global regulator Gcn4p.
No sample metadata fields
View SamplesTo ask whether MANF contributes to the rejuvenating effects of heterochronic parabiosis, we generated heterochronic pairs in which 20 month old WT mice were combined with either 4 month old MANFHet (O-YgHet) or WT (O-YgWT) littermates, and maintained for 5 weeks before analysis. Control pairs in which old WT mice were combined together (O-O) were used. Livers were collected from each animal in the pair and RNA was sequenced for 5 independent animals/condition. Overall design: RNA was extracted and sequenced for 5 animals/condition
MANF regulates metabolic and immune homeostasis in ageing and protects against liver damage.
Age, Subject
View SamplesIn the nervous system, neural stem cells (NSC) are necessary for the generation of new neurons and for cognitive function. Here we show that FoxO3, a member of a transcription factor family known to extend lifespan in invertebrates, regulates the NSC pool. We find that adult FoxO3-/- mice have fewer NSC in vivo than wild type counterparts. NSC isolated from adult FoxO3-/- mice have decreased self-renewal and an impaired ability to generate different neural lineages. Identification of the FoxO3-dependent gene expression profile in NSC suggests that FoxO3 regulates the NSC pool by inducing a program of genes that preserves quiescence, prevents premature differentiation, and controls oxygen metabolism. The ability of FoxO3 to prevent the premature depletion of NSC might have important implications for counteracting brain aging in long-lived species.
FoxO3 regulates neural stem cell homeostasis.
Specimen part
View SamplesThe biotrophic fungus Ustilago maydis causes smut disease on maize (Zea mays L.), which is characterized by immense plant tumours. To establish disease and reprogram organ primordia to tumours, U. maydis deploys effector proteins in an organ-specific manner. However, the cellular contribution to leaf tumours remains unknown. We investigated leaf tumour formation on the tissue- and cell type-specific level. Cytology and metabolite analysis were deployed to understand the cellular basis for tumourigenesis. Laser-capture microdissection was performed to gain a cell-type specific transcriptome of U. maydis during tumour formation. In-vivo visualization of plant DNA synthesis identified bundle sheath cells as the origin of hyperplasic tumour cells, while mesophyll cells become hypertrophic tumour cells. Cell type specific transcriptome profiling of U. maydis revealed tailored expression of fungal effector genes. Moreover, U. maydis See1 was identified the first cell type specific fungal effector, being required for induction of cell cycle reactivation in bundle sheath cells. Identification of distinct cellular mechanisms in two different leave cell types, and See1 as an effector for induction of proliferation of bundle-sheath cells, are major steps in understanding U. maydis-induced tumor formation. Moreover, the cell-type specific U. maydis transcriptome data is a valuable resource to the scientific community. Overall design: To analyze the cell type specific transcriptome of U. maydis during the indcution of plant tumors, transcriptomic profiling of U. maydis from LCM-dissected tumour cells was done. At 4 dpi, SG200 infected HTT cells, bundle sheath-derived HPT cells, and SG200?see1 infected HTT cells (?see1 HTT) were isolated. As controls, mesophyll and bundle sheath cells from mock treated leaf tissue of the same age were isolated.
Cell type specific transcriptional reprogramming of maize leaves during Ustilago maydis induced tumor formation.
Specimen part, Subject
View SamplesTissue resident memory (Trm) represent a newly described memory T cell population. We have previously characterized a population of Trm that persists within the brain following acute virus infection. Although capable of providing marked protection against a subsequent local challenge, brain Trm do not undergo recall expansion following dissociation from the tissue. Furthermore, these Trm do not depend on the same survival factors as the circulating memory T cell pool as assessed either in vivo or in vitro. To gain greater insight into this population of cells we compared the gene-expression profiles of Trm isolated from the brain to circulating memory T cells isolated from the spleen following an acute virus infection. Trm displayed altered expression of genes involved in chemotaxis, expressed a distinct set of transcription factors and overexpressed several inhibitory receptors. Cumulatively, these data indicates that Trm are a distinct memory T cell population disconnected from the circulating memory T cell pool and displaying a unique molecular signature which likely results in optimal survival and function within their local environment.
The molecular signature of tissue resident memory CD8 T cells isolated from the brain.
Specimen part
View SamplesWild type, pkl, pkr2 and pkl pkr2 plants were grown, and gene expression in roots was compared at the age of 5 days. <br></br>
CHD3 proteins and polycomb group proteins antagonistically determine cell identity in Arabidopsis.
Age, Specimen part, Time
View Samples