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 SamplesTherapeutic hypothermia is a clinically effective treatment for various hypoxic and ischemic conditions, but the associated molecular mechanisms remain unclear. To gain insight into hypothermia-induced transcriptional response, mouse embryonic fibroblasts were exposed to mild hypothermia (32C) or normothermia (37C) for increasing time periods. We aimed to identify genes with temporally near-monotonic response as the most obvious candidates for mediating the therapeutic effects of hypothermia.
Estimating differential expression from multiple indicators.
Specimen part, Time
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 SamplesPeriostin participates in different processes involved in connective tissue homeostasis. It is also involved in repairment of damaged tissues. We used the osteoblast murine cell line MC3T3-E1 cell line to show how overexpresion of periostin is able to increase their adhesion properties while diminishing their migration capacity. By differential gene expression we evaluated putative targets involved in those cellular properties.
Role of Periostin in Adhesion and Migration of Bone Remodeling Cells.
Specimen part, Cell line
View SamplesDJ-1 is an atypical peroxiredoxin-like peroxidase that may act as a redox-dependent chaperone and a regulator of transcription. To explore DJ-1-mediated transcriptional control in Parkinsons disease (PD), we generated human neuroblastoma cells with inducible knock-down of DJ-1 expression. We then used functional genomic techniques to identify novel pathways dysregulated by loss of DJ-1 function. Using microarray gene expression profiling, we found that DJ-1 silencing alters the expression of 26 genes, with 10 down-regulated and 16 up-regulated transcripts. Among the down-regulated genes we found Ret, tyrosine kinase receptor for the neurotrophic factor GDNF. Taking advantage of Ingenuity Pathways Analysis, we identified hypoxia inducible factor 1 alpha (Hif1a) as a possible mediator of the interplay between DJ-1 and Ret. We show that Hif1a is stabilized in the absence of DJ-1, and that loss of DJ-1 generates hypoxia and accumulation of free radical species (ROS). Overexpression of wt DJ-1, but not of C106A and L166P mutants deficient in ROS scavenger activity, rescues Ret expression in neuroblastoma cells. These findings reveal novel players in PD pathogenesis and provide evidence for additional pathways involved in DJ-1-mediated neurodegeneration.
Parkinson disease-associated DJ-1 is required for the expression of the glial cell line-derived neurotrophic factor receptor RET in human neuroblastoma cells.
Specimen part, Cell line
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 SamplesThis SuperSeries is composed of the SubSeries listed below.
A Preclinical Model for ERα-Positive Breast Cancer Points to the Epithelial Microenvironment as Determinant of Luminal Phenotype and Hormone Response.
Specimen part
View SamplesA high percentage of potential oncology drugs fail in clinical trials, partly because preclinical models used to test them are inadequate. Breast cancer is the leading cause of cancer-related death among women worldwide but we lack appropriate in vivo models for the ER+ subtypes, which represent more than 75% of all cases. We address these issues by xenografting tumor cells to their site of origin, the milk ducts. All ER+ cell lines and patient-derived xenografts grow mimicking their clinical counterparts. Disease progresses with invasion and metastasis, which become amenable to study. The action of hormones, important in breast carcinogenesis, can now be studied in a relevant context. Importantly, these open opportunities for development and evaluation of therapies.
A Preclinical Model for ERα-Positive Breast Cancer Points to the Epithelial Microenvironment as Determinant of Luminal Phenotype and Hormone Response.
Specimen part
View SamplesA high percentage of potential oncology drugs fail in clinical trials, partly because preclinical models used to test them are inadequate. Breast cancer is the leading cause of cancer-related death among women worldwide but we lack appropriate in vivo models for the ER+ subtypes, which represent more than 75% of all cases. We address these issues by xenografting tumor cells to their site of origin, the milk ducts. All ER+ cell lines and patient-derived xenografts grow mimicking their clinical counterparts. Disease progresses with invasion and metastasis, which become amenable to study. The action of hormones, important in breast carcinogenesis, can now be studied in a relevant context. Importantly, these open opportunities for development and evaluation of therapies.
A Preclinical Model for ERα-Positive Breast Cancer Points to the Epithelial Microenvironment as Determinant of Luminal Phenotype and Hormone Response.
Specimen part
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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