Experiments in rodents have shown that kidney ischemia/reperfusion injury (IRI) facilitates lung injury and inflammation. To identify potential ischemia-specific lung molecular pathways involved, we conducted global gene expression profiling of lung 6 or 36 hours following 1) bilateral kidney IRI, 2) bilateral nephrectomy (BNx), and 3) sham laparotomy in C57BL/6J mice. Total RNA from whole lung was isolated and hybridized to 430MOEA (22,626 genes) GeneChips (n=3/group).
Ischemic acute kidney injury induces a distant organ functional and genomic response distinguishable from bilateral nephrectomy.
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View SamplesWe sought to confirm the genetic influence in the development of Ventilation-Associated Lung Injury (VALI) and, in the process, identify potential candidate genes involved in the disease by integrating differential gene expression profiling on rat lungs to a traditional strain survey analysis of the parental rat strains, VALI-sensitive Brown Norway rats versus VALI-resistant Dahl Salt Sensitive rats, comparing control (under room air ventilation) versus under high tidal volume (HTV) ventilation.
Use of consomic rats for genomic insights into ventilator-associated lung injury.
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View SamplesRATIONALE: Mechanical ventilation (MV) is an indispensable therapy for critically ill patients with acute lung injury and the adult respiratory distress syndrome. However, the mechanisms by which conventional MV induces lung injury remain unclear. OBJECTIVES: We hypothesized that disruption of the gene encoding Nrf2, a transcription factor which regulates the induction of several antioxidant enzymes, enhances susceptibility to ventilator-induced lung injury (VILI), while antioxidant supplementation attenuates such effect. METHODS: To test our hypothesis and to examine the relevance of oxidative stress in VILI, here we have assessed lung injury and inflammatory responses in Nrf2-deficient (Nrf2(-/-)) mice and wildtype (Nrf2(+/+)) animals following acute (2 h) injurious model of MV with or without administration of antioxidant. MEASUREMENTS AND MAIN RESULTS: Nrf2(-/-) mice displayed greater levels of lung alveolar and vascular permeability and inflammatory responses to MV as compared to Nrf2(+/+) mice. Nrf2-deficieny enhances the levels of several pro-inflammatory cytokines implicated in the pathogenesis of VILI. We found diminished levels of critical antioxidant enzymes and redox imbalance by MV in the lungs of Nrf2(-/-) mice; however antioxidant supplementation to Nrf2(-/-) mice remarkably attenuated VILI. When subjected to clinically relevant prolong period of MV, Nrf2(-/-) mice displayed greater levels of VILI than Nrf2(+/+) mice. Expression profiling revealed lack of induction of several VILI genes, stress response and solute carrier proteins and phosphatases in Nrf2(-/-) mice. CONCLUSIONS: Collectively, our data demonstrate for the first time a critical role for Nrf2 in VILI, which confers protection against cellular responses induced by MV by modulating oxidative stress.
Genetic and pharmacologic evidence links oxidative stress to ventilator-induced lung injury in mice.
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View SamplesType I interferons were discovered as the primary antiviral cytokines and are now known to serve critical functions in host defense against bacterial pathogens. Accordingly, established mediators of interferon antiviral activity may mediate previously unrecognized antibacterial functions. RNase-L is the terminal component of an RNA decay pathway that is an important mediator of interferon-induced antiviral activity. Here we identify a novel role for RNase-L in the host antibacterial response. RNase-L-/- mice exhibited a dramatic increase in mortality following
An essential role for the antiviral endoribonuclease, RNase-L, in antibacterial immunity.
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View SamplesEpilepsy is a major neurological disorder that affects approximately 1% of the population. The processes that lead to the development of epilepsy (epileptogenesis) are largely unknown. Levetiracetam is a novel antiepileptic drug (AED) that in the kindling model inhibits epileptogenesis in addition to being effective in controlling established epilepsy. The mechanisms of action of levetiracetam as an AED and an antiepileptogenic drug are unknown. By identifying the effect of chronic levetiracetam therapy on gene expression in the brain we hope to be able to identify genes that are involved in epileptogenesis. By comparing the gene expression profiles of levetiracetam and phenytoin treatments, we hope to be able to distinguish between genes that are important for the antiepileptic (anti-seizure) effect and genes that are important for the antiepileptogenic effect of levetiracetam. Phenytoin is a well-established AED; its mechanism of action involves inhibition of sodium channels. In contrast to levetiracetam, available data suggest that phenytoin in certain situations may enhance rather than inhibit the development of epilepsy.
Region-specific changes in gene expression in rat brain after chronic treatment with levetiracetam or phenytoin.
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View SamplesWe investigate the biological effects of radiation using Drosophila Melanogaster as a model organism, focusing on gene expression and lifespan analysis to determine the effect of different radiation doses. Our results support a threshold effect in response to radiation: no effect on lifespan and no permanent effect on gene expression is seen at doses below 10,000 Roentgens. Overall design: Adult male Drosophila were irradiated 2 days after eclosion, with one of 6 radiation doses: 10; 1,000; 5,000; 10,000; 20,000 Roentgens. Samples were taken at 3 time points (2, 10 and 20 days post-irradiation).
Drosophila melanogaster show a threshold effect in response to radiation.
Specimen part, Subject
View SamplesThis study describes a temporal profile of gene expression from normal human fetal testes and ovaries. Gonads from 34 fetuses between 9 weeks and 20 weeks of gestation were obtained from the Department of Pathology and the Birth Defects Research Laboratory at the University of Washington. Relative transcript levels were determined using the Affymetrix Human Genome U133A Plus 2.0 arrays.
Global gene expression in the human fetal testis and ovary.
Specimen part
View SamplesThe transcription factor OTX2 has been implicated as an oncogene in medulloblastoma, which is the most common malignant brain tumor in children. It is highly expressed in most medulloblastomas and amplified in a subset of them. The role of OTX2 in medulloblastoma and its downstream targets are unclear. Therefore, we generated D425 medulloblastoma cells in which we can silence endogenous OTX2 by inducible shRNA. Silencing of OTX2 strongly inhibited cell proliferation and resulted in a neuronal-like differentiation. Expression profiling of time courses after silencing showed a progressive change in gene expression for many cellular processes. Down regulated genes were highly enriched for cell cycle and visual perception genes, while up regulated genes were enriched for genes involved in development and differentiation. This shift in expression profiles is reminiscent to changes described to occur during normal cerebellum development. OTX2 is expressed in proliferating granular progenitor cells, but the expression diminishes when these cells exit the cell cycle and start differentiating. ChIP-on-chip analyses of OTX2 in D425 cells showed that cell cycle and perception genes were direct OTX2 targets, while regulation of most differentiation genes appears to be indirect. These analyses provide the first insight in the molecular network of OTX2, demonstrating that OTX2 is essential in medulloblastoma and directly drives proliferation by regulating the expression of cell cycle genes. Since many of these genes also correlate in expression with OTX2 in primary tumors, they might be potential targets for therapy in medulloblastoma patients.
OTX2 directly activates cell cycle genes and inhibits differentiation in medulloblastoma cells.
Cell line, Time
View SamplesWe used microarrays to assess gene expression in patients with ET, PV, and PMF compared to control subjects
Whole-blood transcriptional profiling of interferon-inducible genes identifies highly upregulated IFI27 in primary myelofibrosis.
Specimen part, Disease
View SamplesMillions of patients suffer from lymphedema worldwide. Supporting the contractility of lymphatic collectors is an attractive target for pharmacological therapy of lymphedema. However, lymphatics have mostly been studied in animals, while the cellular and molecular characteristics of human lymphatic collectors are largely unknown. We studied epifascial lymphatic collectors of the thigh, which were isolated for autologous transplantations. Our immunohistological studies identify additional markers for LECs (vimentin, CCBE-1). We show and confirm differences between initial and collecting lymphatics concerning the markers ESAM1, D2-40 and LYVE-1. Our transmission electron microscopic studies reveal two types of smooth muscle cells (SMCs) in the media of the collectors with dark and light cytoplasm. We observed vasa vasorum in the media of the largest collectors, as well as interstitial Cajal-like cells, which are highly ramified cells with long processes, caveolae, and lacking a basal lamina. They are in close contact with SMCs, which possess multiple caveolae at the contact sites. Immunohistologically we identified such cells with antibodies against vimentin and PDGFRa, but not CD34 and cKIT. With Next Generation Sequencing we searched for highly expressed genes in the media of lymphatic collectors, and found therapeutic targets, suitable for acceleration of lymphatic contractility, such as neuropeptide Y receptors 1, and 5; tachykinin receptors 1, and 2; purinergic receptors P2RX1, and 6, P2RY12, 13, and 14; 5-hydroxytryptamine receptors HTR2B, and 3C; and adrenoceptors a2A,B,C. Our studies represent the first comprehensive characterization of human epifascial lymphatic collectors, as a prerequisite for diagnosis and therapy. Overall design: The transcriptome of 6 different normal human lymphatic collectors (Lyko1, Lyko 4-12, Lyko 5, Lyko12, Lyko13, Lyko26) from the dermis of the thigh of women between 44 and 61 years of age was compared to cultures of human dermal lymphatic endothelial cells (LEC1, LEC2, HD-LEC9A) and a mixture of 3 different human dermal blood endothelial cells (HD-BEC-CA) to identify potential drug targets in the media of the collectors.
Morphological and Molecular Characterization of Human Dermal Lymphatic Collectors.
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