The eukaryotic genome is organized in a three-dimensional structure called chromatin, constituted by DNA and associated proteins, the majority of which are histones. Post-translational modifications of histone proteins greatly influence chromatin structure and regulate many DNA-based biological processes. Methylation of lysine 36 of histone 3 (H3K36) is a post-translational modification functionally relevant during early steps of DNA damage repair. Here, we show that the JMJD-5 regulates H3K36 di-methylation and it is required at late stages of double strand break repair mediated by homologous recombination. Loss of jmjd-5 results in hypersensitivity to ionizing radiation and in meiotic defects, and it is associated with aberrant retention of RAD-51 at sites of double strand breaks. Analyses of jmjd-5 genetic interactions with genes required for resolving recombination intermediates (rtel-1) or promoting the resolution of RAD-51 double stranded DNA filaments (rfs-1 and helq-1) suggest that jmjd-5 prevents the formation of stalled postsynaptic recombination intermediates and favors RAD-51 removal. As these phenotypes are all recapitulated by a catalytically inactive jmjd-5 mutant, we propose a novel role for H3K36me2 regulation during late steps of homologous recombination critical to preserve genome integrity. Overall design: RNA sequencing of N2 and jmjd-5(tm3735) at 20C and 25C at generation 1 (G1) and generation 6 (G6)
JMJD-5/KDM8 regulates H3K36me2 and is required for late steps of homologous recombination and genome integrity.
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 SamplesThe PLZF transcription factor is essential for osteogenic differentiation of hMSCs, however, its regulation and molecular function during this process is not fully understood. Here we revealed that the ZBTB16 locus encoding PLZF, is repressed by Polycomb (PcG) and H3K27me3 in naïve hMSCs. At the pre-osteoblast stage of differentiation, the locus lost PcG binding and H3K27me3, gained JMJD3 recruitment, and H3K27ac resulting in high expression of PLZF. Subsequently, PLZF was recruited to osteogenic enhancers, influencing H3K27 acetylation and expression of nearby genes important for osteogenic function. Furthermore, we identified a latent enhancer within the ZBTB16/PLZF locus itself that became active, gained PLZF, p300 and Mediator binding and looped to the promoter of the nicotinamide N-methyltransferase (NNMT) gene. The increased expression of NNMT correlated with a decline in SAM levels, which is dependent on PLZF and is required for osteogenic differentiation. Overall design: Effect of PLZF knockdown on osteogenic differentiation of hMSC (RNAseq)
PLZF targets developmental enhancers for activation during osteogenic differentiation of human mesenchymal stem cells.
Specimen part, Subject
View SamplesGuillain-Barré syndrome (GBS) is an immune-mediated peripheral neuropathy that debilitates the voluntary and autonomous response of the patient. In this study the transcriptome of peripheral blood mononuclear cells from a GBS patient and her healthy twin were compared to discover possible correlates of disease progression and recovery. Overall design: Blood samples were collected simultaneously from the Guillain-Barré patient (A) and from her control healthy twin (B) at three different time points during disease progression from hospitalization in the intensive care unit (T1), passing to intermediate care (T2), and at conclusion of locomotion rehabilitation program when the patient was close to abandon the hospital (T3).
Expression of Early Growth Response Gene-2 and Regulated Cytokines Correlates with Recovery from Guillain-Barré Syndrome.
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View SamplesIGF-I exert multiple effects in different retinal cell populations in both physiological and pathological conditions. Transgenic mice overexpressing IGF-I in the retina showed impaired electroretinographic responses at 6-7 months of age that worsen with age. This retinal neuronal dysfunction was correlated with the loss of rod photoreceptors, bipolar, ganglion and amacrines cells. Neuronal alterations were preceded by the overexpression of retinal stress markers, acute phase proteins and gliosis-related genes. IGF-I overexpression leads to chronic gliosis and microgliosis in TgIGF-I retinas, with mild oxidative stress, impaired recycling of glutamate and defective potassium buffering. These impaired supportive functions can contribute to neurodegeneration in TgIGF-I retinas, together with the increased production of pro-inflammatory cytokines, potential mediators of neuronal death.
Insulin-like Growth Factor 2 Overexpression Induces β-Cell Dysfunction and Increases Beta-cell Susceptibility to Damage.
Sex, Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Aberrant epigenome in iPSC-derived dopaminergic neurons from Parkinson's disease patients.
Sex, Specimen part, Disease, Disease stage, Subject
View SamplesWe analysed the RNA profile of IPSC-derived dopaminergic neurons from idiophatic and genetic form (LRRK2) of Parkinsons disease (PD). Both, idiopathic and genetic form of the disease show similar expression alterations and were merged in one whole PD group. We found 437 differentially expressed genes (DEGs) in the PD group as a whole. Up-regulated DEGs (n=254) encompassed genes involved in neural functions and transcription factor functions whereas down-regulated DEGs (n=183) affected basic homeostasis. These data point towards the presence of gene - and also protein - expression changes in DAn from PD patients which co-occur simultaneously along with DNA methylation changes.
Aberrant epigenome in iPSC-derived dopaminergic neurons from Parkinson's disease patients.
Sex, Specimen part, Disease, Disease stage
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 SamplesOxidative stress can arise when in vitro propagated plants developed under low light conditions are exposed to high light during transfer to ex vitro conditions. In such a situation, among the many potential stresses to which the transferred plant can be exposed, oxidative stress is commonly experienced, most likely brought about by absorption of light energy in excess of that required for very low levels of photosynthetic metabolism. In vitro propagated grapevine when transferred to ex vitro conditions with a 4 fold increase in PPFD shows an initial inhibition of PET accompanied by an accumulation of H2O2, suggesting a signal for the upregulation in gene expression and antioxidant enzyme activity, which peaked at 48h after transfer of in vitro grapevine to ex vitro growing conditions.
Comparative transcriptomic profiling of Vitis vinifera under high light using a custom-made array and the Affymetrix GeneChip.
Specimen part, Treatment
View SamplesChromosomal instability (CIN) is defined by the propensity to acquire structural and/or numerical aberration in the normal cellular karyotype and is often associated with cancer. Autophagy is a catabolic process that leads to the recycling of cellular components that may positively or negatively impact on cancer development and progression, depending on the context. Recent work postulated that the depletion of the pro-autophagic and tumor suppressive protein Beclin 1 triggers CIN by interfering with mitotic chromosome segregation, providing a possible mechanism for how Beclin 1 can act as a tumor suppressor (Fremont et al., PMID: 23478334). Here, we present data supporting the notion that the phenotypes described in Fremont et al., depend on a siRNA off-target effect. The transcriptomic analysis shown here was designed to identify the factor(s) that are responsible for such phenotype.
Beclin 1 is dispensable for chromosome congression and proper outer kinetochore assembly.
Cell line
View Samples