Ischemia/reperfusion injuries is a known complication to hepatic surgery. Ischemic pre- (IPC) and postconditioning (IPO) protects the liver against ischemia/reperfusion-injuries. Expression profiling were performed on liver biopsies seeking to identify molecular mediators of the protective properties.
Ischemic pre- and postconditioning has pronounced effects on gene expression profiles in the rat liver after ischemia/reperfusion.
Sex
View SamplesAstrocyte dysfunction impacts their normal function, including neuronal support, thereby contributing to neurodegenerative pathologies including Alzheimer's disease (AD). Therefore to understand the role of astrocytes in the pathogenesis of age-related disorders we analysed the gene expression profile of astrocytes with respect to Alzheimer-type pathology.
Microarray analysis of the astrocyte transcriptome in the aging brain: relationship to Alzheimer's pathology and APOE genotype.
Specimen part
View SamplesHigh levels of oxidative stress and an associated neuronal DDR occur at the earliest stages of Alzheimer pathology (low Braak stage), and is associated with cognitive impairment.
Neuronal DNA damage response-associated dysregulation of signalling pathways and cholesterol metabolism at the earliest stages of Alzheimer-type pathology.
Specimen part
View SamplesHuman diffuse intrinsic pontine gliomas (DIPG) are an aggressive form of pediatric brain tumors that arise in the pons in young children thus resulting in significant morbidity and very poor survival. Recent data suggest that mutations in the histone H3.3 variant are often found in these tumors, though the mechanism of their contribution to oncogenesis remains to be elucidated. Here we report that the combination of constitutive PDGFRA activation and p53 suppression as well as expression of the K27M mutant form of the histone H3.3 variant leads to neoplastic transformation of hPSC-derived neural precursors. Our study demonstrates that human ES cells represent an excellent platform for the modeling of human tumors in vitro and in vivo, which could potentially lead to the elucidation of the molecular mechanisms underlying neoplastic transformation and the identification of novel therapeutic targets.
Use of human embryonic stem cells to model pediatric gliomas with H3.3K27M histone mutation.
Specimen part
View SamplesSamples in this study probe the gene expression kinetics in human CCR6+ Th17 memory T cells activated under Th17 condition. Human CCR6+ Th17 memory T cells were purified from PBMC and gene expression was studied over a time course of 3 days after activation under Th17 condition. RNA from these samples was also profiled using RNA-Seq to compare different transcriptome profiling technologies.
Comparison of RNA-Seq and microarray in transcriptome profiling of activated T cells.
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View SamplesSeveral lipocalin genes from higher plants were shown to be responsive to both high and low temperature stresses and have been named as temperature-induced lipocalin (Til). In this study, a reverse genetic approach was taken to elucidate the role of Arabidopsis Til1 (At5g58070) in thermotolerance. We showed that Til1 proteins was constitutively expressed and increased significantly after heat shock treatment. A T-DNA knockout line of Til1, designated as til1-1, could not produce Til1 and showed severe defects in basal and acquired thermotolerance. Introducing a wild type copy of Til1 gene into til1-1 complemented the mutant phenotype. Over-expression of Til1 in the wild type plant did not enhance thermotolerance. Til1 is peripherally associated with plasma membrane, suggesting a regulatory or protective role of this protein in membrane function. Transcriptomic analysis showed that the heat shock response in til1-1 was not altered as compared to the wild type plants. The temperature threshold for heat shock protein induction was not affected by the level of Til1. Ion leakage analysis revealed no significant difference in membrane stability between the wild type and til1-1 seedlings. These results suggested that Til1 is not involved in regulating membrane fluidity or stability. Nevertheless, the level of malondialdehyde was significantly higher in til1-1 than in the wild type after severe heat treatment. The mutant plants were also more sensitive than the wild type to tert-butyl hydroperoxide, a reagent that induces lipid peroxidation. Taken together, our data indicate that Til1 is an essential component for thermotolerance probably by acting against lipid peroxidation induced by severe heat stress.
Temperature-induced lipocalin is required for basal and acquired thermotolerance in Arabidopsis.
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View SamplesAcquisition of the lower jaw (mandible) was evolutionarily important for jawed vertebrates. In humans, syndromic craniofacial malformations often accompany jaw anomalies. Hand2 is involved in coordinating the developmental network of mandibles and the oral apparatus through Hand2-downstream genes and is therefore a major determinant of jaw identity.
Specification of jaw identity by the Hand2 transcription factor.
Specimen part
View SamplesVitamin D receptors (VDR) are abundantly expressed in developing zebrafish as early as 48 hours post-fertilization, and prior to the development of a mineralized skeleton, and mature intestine and kidney. We probed the role of VDR in zebrafish biology by examining changes in expression of RNA by whole transcriptome shotgun sequencing (RNA-seq) in fish treated with picomolar concentrations of the VDR ligand and hormonal form of vitamin D3, 1a,25-dihydroxyvitamin D3 (1a,25(OH)2D3). We observed significant changes in RNAs encoding proteins of fatty acid, amino acid, and xenobiotic metabolism pathways, and RNAs of transcription factors, leptin, peptide hormones, receptor-activator of NFkB ligand (RANKL), and calcitonin-like ligand receptor pathways. Early small, and subsequent massive changes in >10% of expressed cellular RNAs were observed. At day 2 (24h 1a,25(OH)2D3-treatment), only 5 RNAs were differentially expressed (hormone vs. vehicle). On day 4 (72h-treatment), 78 RNAs; on day 6 (120h-treatment) 1040 RNAs; and on day 7 (144h-treatment), 1755 RNAs were differentially expressed in response to 1a,25(OH)2D3. Fewer RNAs (n = 482) were altered in day 7 embryos treated for 24h with 1a,25(OH)2D3 vs. those treated with hormone for 144h. At 7 days, in 1a,25(OH)2D3-treated embryos, pharyngeal cartilage was larger and mineralization was greater. Changes in expression of RNAs for transcription factors, peptide hormones, and RNAs encoding proteins integral to fatty acid, amino acid, leptin, calcitonin-like ligand receptor, RANKL and xenobiotic metabolism pathways, demonstrate heretofore unrecognized mechanisms by which 1a,25(OH)2D3 functions in vivo in developing eukaryotes. Overall design: Zebrafish embryos were obtained from mating of Segrest wild-type (SWT) parents under controlled barrier conditions, in the Mayo Clinic Zebrafish Core Facility, in Instant Ocean media . Zebrafish embryos (25-30) were placed in 20 mL embryo medium (pH 7.2) containing 1-phenyl-2-thiourea (PTU) (0.003% (w/v) and were maintained at 28-30 oC. At 24 hpf (1 day post fertilization, dpf), 10 microliters of 1a,25(OH)2D3 in ethanol was added to embryos maintained in 20 mL fresh embryo medium with PTU. The final concentration of 1a,25(OH)2D3 was 300 pM. Control zebrafish were treated with 10 microliters ethanol alone (vehicle controls). The medium containing either 300 pM 1a,25(OH)2D3 or vehicle was changed every 24 h . In experiment 1, at 2, 4, 6 and 7 dpf embryos/larvae were removed and immediately frozen at -80 0C for later RNA preparations. 25-30 embryos per set were used for preparation on RNA. At the same times, 7-12 embryos were fixed in 4% paraformaldehyde in 0.75 X Dulbecco's phosphate buffered saline (DPBS). In experiment 2, 6 dpf larvae were treated with 1a,25(OH)2D3 (300 pM) or vehicle for 24 h. RNA was prepared from three sets of larvae.
Detection of 1α,25-dihydroxyvitamin D-regulated miRNAs in zebrafish by whole transcriptome sequencing.
No sample metadata fields
View SamplesTen-eleven translocation (Tet) family of DNA dioxygenases converts 5-methylcytosine (5mC) into 5-hydroxymethylcytosine (5hmC), 5-formylcytosine (5fC), and 5- carboxylcytosine (5caC) through iterative oxidation reactions. While 5mC and 5hmC are relatively abundant, 5fC and 5caC are at very low levels in the mammalian genome. Thymine DNA glycosylase (TDG) and base excision repair (BER) pathways can actively remove 5fC/5caC to regenerate unmethylated cytosine, but it is unclear to what extent and at which part of the genome such active demethylation processes take place. Here, we have performed high-throughput sequencing analysis of 5mC/5hmC/5fC/5caC- enriched DNA using modification-specific antibodies and generated genome-wide distribution maps of these cytosine modifications in wild-type and Tdg-deficient mouse embryonic stem cells (ESCs). We observe that the steady state 5fC and 5caC are preferentially detected at repetitive sequences in wild-type mouse ESCs. Depletion of TDG causes marked accumulation of 5fC and 5caC at a large number of distal gene regulatory elements and transcriptionally repressed/poised gene promoters, suggesting that Tet/TDG-dependent dynamic cycling of 5mC oxidation states may be involved in regulating the function of these regions. Thus, comprehensive mapping of 5mC oxidation and BER pathway activity in the mammalian genome provides a promising approach for better understanding of biological roles of DNA methylation and demethylation dynamics in development and diseases.
Genome-wide analysis reveals TET- and TDG-dependent 5-methylcytosine oxidation dynamics.
Specimen part
View SamplesMyosteatosis is the pathological accumulation of lipid that occurs in conjunction with atrophy and fibrosis following skeletal muscle injury or disease. Little is known about the mechanisms by which lipid accumulates in myosteatosis, but many studies have demonstrated the degree of lipid infiltration negatively correlates with muscle function and regeneration. Our goal was to identify biochemical pathways that lead to muscle dysfunction and lipid accumulation in injured rotator cuff muscles, a model that demonstrates severe myosteatosis. Adult rats were subjected to a massive tear to the rotator cuff musculature. After a period of either 0 (healthy control), 10, 30, or 60 days, muscles were prepared for RNA sequencing, shotgun lipidomics, metabolomics, biochemical measures, electron microscopy, and muscle fiber contractility. Following rotator cuff injury, there was a decrease in muscle fiber specific force production that was lowest at 30d. There was a dramatic time dependent increase in triacylglyceride content. Interestingly, genes related to not only triacylglyceride synthesis, but also lipid oxidation were largely downregulated over time. Using bioinformatics techniques, we identified that biochemical pathways related to mitochondrial dysfunction and reactive oxygen species were considerably increased in muscles with myosteatosis. Long chain acyl-carnitines and L-carnitine, precursors to beta-oxidation, were depleted following rotator cuff tear. Electron micrographs showed injured muscles displayed large lipid droplets within mitochondria at early time points, and an accumulation of peripheral segment mitochondria at all time points. Several markers of oxidative stress were elevated following rotator cuff tear. The results from this study suggest that the accumulation of lipid in myosteatosis is not a result of canonical lipid synthesis, but occurs due to decreased lipid oxidation in mitochondria. A failure in lipid utilization by mitochondria would ultimately cause an accumulation of lipid even in the absence of increased synthesis. Further study will identify whether this process is required for the onset of myosteatosis. Overall design: Rats were subjected to a bilateral full-thickness supraspinatus tear and suprascapular neurectomy. Samples (N=4 per group) were taken at 0 days (unoperated controls), 10 days, 30 days, and 60 days post-injury
Reduced mitochondrial lipid oxidation leads to fat accumulation in myosteatosis.
No sample metadata fields
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