PURPOSE: Hyperoxia is toxic to photoreceptors, and this toxicity may be important in the progress of retinal dystrophies. This microarray study examines gene expression induced in the C57BL/6J mouse retina by hyperoxia over the 14-day period during which photoreceptors first resist, then succumb to, hyperoxia. METHODS: Young adult C57BL/6J mice were exposed to hyperoxia (75% oxygen) for up to 14 days. On day 0 (control), day 3, day 7, and day 14, retinal RNA was extracted and processed on Affymetrix GeneChip Mouse Genome 430 2.0 arrays. Microarray data were analyzed using GCOS Version 1.4 and GeneSpring Version 7.3.1. RESULTS: The overall numbers of hyperoxia-regulated genes increased monotonically with exposure. Within that increase, however, a distinctive temporal pattern was apparent. At 3 days exposure, there was prominent upregulation of genes associated with neuroprotection. By day 14, these early-responsive genes were downregulated, and genes related to cell death were strongly expressed. At day 7, the regulation of these genes was mixed, indicating a possible transition period from stability at day 3 to degeneration at day 14. CONCLUSIONS: Microarray analysis of the response of the retina to prolonged hyperoxia demonstrated a temporal pattern involving early neuroprotection and later cell death, and provided insight into the mechanisms involved in the two phases of response. As hyperoxia is a consistent feature of the late stages of photoreceptor degenerations, understanding the mechanisms of oxygen toxicity may be important therapeutically.
Gene regulation induced in the C57BL/6J mouse retina by hyperoxia: a temporal microarray study.
Specimen part
View SamplesTemporal genome profiling of DSS colitis
Temporal genomewide expression profiling of DSS colitis reveals novel inflammatory and angiogenesis genes similar to ulcerative colitis.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
FMRP stalls ribosomal translocation on mRNAs linked to synaptic function and autism.
Sex, Specimen part
View SamplesThe Fragile X Mental Retardation Protein, FMRP, is thought to regulate the translation of a specific set of neuronal mRNAs on polyribosomes. Therefore, we prepared polyribosomes on sucrose gradients and purified mRNA specifically from these fractions, as well as the total mRNA levels, to determine whether a set of mRNAs might be changed in its % association with polyribosomes in the absence of FMRP in the KO mouse model.
FMRP stalls ribosomal translocation on mRNAs linked to synaptic function and autism.
Sex, Specimen part
View SamplesRNAseq analysis of cloche m39 mutant zebrafish embryos and wild type siblings at 90% epiboly - tailbud stage Overall design: In order to isolate the cloche gene, RNAseq was performed on a deletion allele of the zebrafish cloche mutant. RNA was extracted from individual embryos at a stage the cloche gene was predicted to be expressed based on previous literature. RNA from the respective genoptypes was then pooled and subjected to RNAseq analysis.
Cloche is a bHLH-PAS transcription factor that drives haemato-vascular specification.
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View SamplesThis SuperSeries is composed of the SubSeries listed below.
Specific microRNAs are preferentially expressed by skin stem cells to balance self-renewal and early lineage commitment.
Sex, Specimen part, Treatment
View SamplesIncreasing evidence suggests that microRNAs may play important roles in regulating self-renewal and differentiation in mammalian stem cells (SCs). Here, we explore this issue in skin. We first characterize microRNA expression profiles of skin SCs versus their committed proliferative progenies and identify a microRNA subset associating with stemness. Of these, miR-125b is dramatically downregulated in early SC-progeny. We engineer an inducible mice system and show that when miR-125b is sustained in SC-progenies, tissue balance is reversibly skewed towards stemness at the expense of epidermal, oil-gland and HF differentiation. Using gain-and-loss of function in vitro, we further implicate miR-125b as a repressor of SC differentiation. In vivo, transcripts repressed upon miR-125b induction are enriched >700% for predicted miR-125b targets normally downregulated upon SC-lineage commitment. We verify some of these miR-125b targets, and show that Blimp1 and VDR in particular can account for many tissue imbalances we see when miR-125b is deregulated.
Specific microRNAs are preferentially expressed by skin stem cells to balance self-renewal and early lineage commitment.
Sex, Specimen part, Treatment
View SamplesIncreasing evidence suggests that microRNAs may play important roles in regulating self-renewal and differentiation in mammalian stem cells (SCs). Here, we explore this issue in skin. We first characterize microRNA expression profiles of skin SCs versus their committed proliferative progenies and identify a microRNA subset associating with stemness. Of these, miR-125b is dramatically downregulated in early SC-progeny. We engineer an inducible mice system and show that when miR-125b is sustained in SC-progenies, tissue balance is reversibly skewed towards stemness at the expense of epidermal, oil-gland and HF differentiation. Using gain-and-loss of function in vitro, we further implicate miR-125b as a repressor of SC differentiation. In vivo, transcripts repressed upon miR-125b induction are enriched >700% for predicted miR-125b targets normally downregulated upon SC-lineage commitment. We verify some of these miR-125b targets, and show that Blimp1 and VDR in particular can account for many tissue imbalances we see when miR-125b is deregulated.
Specific microRNAs are preferentially expressed by skin stem cells to balance self-renewal and early lineage commitment.
Specimen part
View SamplesPolycomb protein group (PcG)-dependent trimethylation on H3-K27(H3K27me3) regulates identity of embryonic stem cells (SCs). How H3K27me3 governs adult SCs and tissue development is unclear. Here, we conditionally target H3-K27-methyltransferases Ezh2 and Ezh1 to address their roles in mouse skin homeostasis. Postnatal phenotypes appear only in doubly-targeted skin, where H3K27me3 is abolished, revealing functional redundancy in EZH1/2 proteins. Surprisingly, while Ezh1/2-null hair follicles (HFs) arrest morphogenesis and degenerate due to defective proliferation and increased apoptosis, epidermis hyperproliferates and survives engraftment. mRNA-microarray studies reveal that despite these striking phenotypic differences, similar genes are upregulated in HF and epidermal Ezh1/2-null progenitors. Featured prominently are a) PcG-controlled non-skin lineage genes, whose expression is still significantly lower than in native tissues, and b) the PcG-regulated Ink4a/Inkb/Arf locus. Interestingly, even though Ink4a/Arf/Ink4b genes are fully activated in HF cells, they only partially so in epidermal-progenitors. Importantly, transduction of Ink4b/Ink4a/Arf shRNAs restores proliferation/survival of Ezh1/2-null HF progenitors in vitro, pointing towards the relevance of this locus to the observed HF phenotypes. Our findings reveal new insights into Polycomb-dependent tissue control and provide a new twist to how different progenitors within one tissue respond to loss of H3K27me3.
EZH1 and EZH2 cogovern histone H3K27 trimethylation and are essential for hair follicle homeostasis and wound repair.
Sex, Age, Specimen part
View SamplesTranscriptional profiling of the zebrafish embryonic host response to a systemic bacterial infection with Salmonella typhimurium (strain SL1027); comparison between traf6 knock-down and control morpholino treated embryos. Overall design: All infection experiments were performed using mixed egg clutches of ABxTL strain zebrafish. Embryos injected with traf6 morpholino or a 5bp mismatch control morpholino were staged at 27 hours post fertilization (hpf) by morphological criteria and approximately 250 cfu of DsRed expressing Salmonella bacteria were injected into the caudal vein close to the urogenital opening. As a control an equal volume of PBS was likewise injected. Pools of 20-40 infected and control embryos were collected 8 hours post infection (hpi). The whole procedure was preformed in triplicate on separate days. Total RNA of the biological triplicates was pooled using equal amounts of RNA prior to RNAseq library preparation.
Transcriptome analysis of Traf6 function in the innate immune response of zebrafish embryos.
No sample metadata fields
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