Domoic acid (DA) is a neuroexcitatory amino acid that is naturally produced by some marine diatom species of the genus Pseudo-nitzschia. Ingestion of DA-contaminated seafood by humans results in a severe neurotoxic disease known as amnesic shellfish poisoning (ASP). Clinical signs of ASP include seizures and neuronal damage from activation of AMPA and kainate receptors. However, the impacts of DA exposure at levels below those known to induce outward signs of neurobehavioral exicitotoxicity have not been well characterized. To further understand the mechanisms of neurotoxic injury associated with DA exposure, we examined the transcriptome of whole brains from zebrafish (Danio rerio) receiving intracoelomic (IC) DA at both symptomatic and asymptomatic doses. A majority of zebrafish exposed to high-dose DA (1.2 g DA/g) exhibited clinical signs of neuroexcitotoxicity (EC50 of 0.86 g DA/g) within 5 to 20 minutes of IC injection. All zebrafish receiving low-dose DA (0.47 g DA/g) or vehicle only maintained normal behavior. Microarray analysis of symptomatic and asymptomatic exposures collectively yielded 306 differentially expressed genes (1.5-fold, p = 0.05) predominately represented by signal transduction, ion transport, and transcription factor functional categories. Transcriptional profiles were suggestive of neuronal apoptosis following an overwhelming of protective adaptive pathways. Further, potential molecular biomarkers of neuropathic injury, including Nrdg4, were identified and may be relevant to DA exposure levels below that causing neurobehavioral injury. Our results validate zebrafish as a vertebrate model to study mechanisms of DA neurotoxicity and provide a basis for identifying pathways of DA-induced injury as well as biomarkers of asymptomatic and symptomatic DA exposure levels.
Gene expression profiles in zebrafish brain after acute exposure to domoic acid at symptomatic and asymptomatic doses.
No sample metadata fields
View SamplesBackground: Diesel exhaust (DE) is the primary source of urban fine particulate matter, which has been associated with cardiovascular disease in epidemiological studies. These effects may be related to oxidative stress and systemic inflammation with resulting perturbation of vascular homeostasis. Peripheral leukocytes are involved in both inflammation and control of vascular homeostasis. Objectives: We conducted an exploratory study using microarray techniques to analyze whether global gene expression in peripheral blood mononuclear cells (PBMCs) can inform on potential mechanisms of effect of DE inhalation. Methods: In a double-blind, crossover, controlled exposure study, healthy adult volunteers were exposed in randomized order to filtered air (FA) and diluted DE in two-hour sessions. We isolated RNA (Trizol/Qiagen method) form PBMCs before, and two times after each exposure. RNA samples were arrayed using the Affymetrix platform (GeneChip Human Genome U133 Plus 2.0 Array). Results: Microarray analyses were conducted on five subjects with available RNA sample form exposures to FA and to the highest DE inhalation (200 g/m of fine particulate matter). Following data normalization and statistical analysis, a total of 1290 out of 54,675 probe sets with significant evidence for differential expression (more than 1.5-fold up or down regulated with p < 0.05) were identified. These include genes involved in inflammatory response (e.g., IL8RA, TNFAIP6, FOS), oxidative stress (e.g., HMOX1, BAX, PRDX1,), and in biochemical pathways like mitogen-activated protein kinases (MAPK) and tight junction pathways. Conclusions: These data suggest that DE may exert time-dependent changes in gene expression in PBMCs in healthy individuals. Genes that may be affected by DE inhalation are involved in inflammatory and oxidative stress processes.
Diesel exhaust inhalation and assessment of peripheral blood mononuclear cell gene transcription effects: an exploratory study of healthy human volunteers.
No sample metadata fields
View SamplesTo understand the global view of dysregulated genes and pathwyas in CRYAAN101D lenses, RNA sequencing of 2 & 4 months old CRYAAWT and CRYAAN101D lenses was carried out. Overall design: Determination of differential gene expression between CRYAAWT and CRYAAN101D in 2 & 4 months old lenses
Molecular mechanism of formation of cortical opacity in CRYAAN101D transgenic mice.
No sample metadata fields
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Blocking promiscuous activation at cryptic promoters directs cell type-specific gene expression.
Specimen part
View SamplesThe effect of different loss of functions; kumgang (kmg or CG5204), dMi-2, and kmg and always early (aly) double on the gene expression in spermatocyte differentation was assessed by microarray.
Blocking promiscuous activation at cryptic promoters directs cell type-specific gene expression.
Specimen part
View SamplesThe innate immune system is vital to rapidly responding to pathogens and Toll-like receptors (TLRs) are a critical component of this response. Nanovesicular exosomes play a role in immunity, but to date their exact contribution to the dissemination of the TLR response is unknown. To understand the effect of exosomal cargo released from locally stimulated cells on distal cell expression, we collected exosomes from local ovarian adenocarcinoma (HEY) cells that were either unstimulated (control-exosomes), stimulated with pIC (pIC-exosomes), or lipopolysaccharide (LPS-exosomes) for 48 hours. The three groups of exosomes were added to nave (distal) cells and the gene expression profiles were compared between local TLR stimulation (for 6 hours) and distal stimulation mediated by exosomes at the 48-hour time point
TLR-exosomes exhibit distinct kinetics and effector function.
Specimen part, Cell line, Treatment
View SamplesTo detect sex-specific differences in gene expression in a model of hyperoxic lung injury in adult C56BL/6J mice.
Analysis of the transcriptome in hyperoxic lung injury and sex-specific alterations in gene expression.
Sex, Specimen part, Treatment
View SamplesThe Melanoma-associated Antigen gene family (MAGE) generally encodes for tumour antigens. We recently have identified one of the MAGE gene members, Mageb16 to be highly expressed in undifferentiated murine embryonic stem cells (mESCs). The role of Mageb16 for the differentiation of the pluripotent stem cells is completely unknown. Here we demonstrate that Mageb16 (41 kDa) is distributed in cytosol and/or in surface membrane in undifferentiated mESCs. A transcriptome study was performed with differentiated short hairpin RNA (shRNA)-mediated Mageb16 knockdown (KD ESCs) and scrambled control (SCR) ESCs until a period of 22 days. Mageb16 KD ESCs mainly differentiated towards mesodermal derivatives such as cardiovascular lineages. Mesoderm-oriented differentiation initiated biological processes such as adipogenesis, osteogenesis, limb morphogenesis and spermatogenesis were significantly enriched in the differentiated Mageb16 KD ESCs. Cardiomyogenesis in differentiated KD mESCs was stronger when compared to differentiated SCR and wild mESCs. The expression of non-coding RNA (ncRNA) Lin28a and other epigenetic regulatory genes, nucleocytoplasmic trafficking and genes participating in spermatogenesis have also declined faster in the differentiating Mageb16 KD ESCs. We conclude that Mageb16 plays a crucial role for differentiation of ESCs, specifically to the mesodermal lineages. Regulative epigenetic networks and nucleocytoplasmic modifications induced by Mageb16 may play a role for the critical role of Mageb16 for the ESCs differentiation.
Depletion of Mageb16 induces differentiation of pluripotent stem cells predominantly into mesodermal derivatives.
Sex, Specimen part
View SamplesOur work demonstrated that miR-183 cluster regulates IFN production and signaling
A conserved miRNA-183 cluster regulates the innate antiviral response.
Cell line
View SamplesThe nuclear receptor peroxisome proliferator-activated receptor alpha (PPAR) regulates responses to chemical or physical stress in part by altering expression of genes involved in proteome maintenance. Many of these genes are also transcriptionally regulated by heat shock (HS) through activation by HS factor-1 (HSF1). We hypothesized that there are interactions on a genetic level between PPAR and the HS response mediated by HSF1. Wild-type and PPAR-null mice were exposed to HS, the PPAR agonist WY-14,643 (WY), or both; gene and protein expression was examined in the livers of the mice 4 or 24 hrs after HS. Gene expression profiling identified a number of Hsp family members that were altered similarly in both mouse strains. However, most of the targets of HS did not overlap between strains. A subset of genes was shown by microarray and RT-PCR to be regulated by HS in a PPAR-dependent manner. HS also down-regulated a large set of mitochondrial genes specifically in PPAR-null mice that are known targets of PPARg co-activator 1 (PGC-1) family members. Pretreatment of PPAR-null mice with WY increased expression of PGC-1b and target genes and prevented the down-regulation of the mitochondrial genes by HS. A comparison of HS genes regulated in our dataset with those identified in wild-type and HSF1-null mouse embryonic fibroblasts indicated that although many HS genes are regulated independently of both PPAR and HSF1, a number require both factors for HS responsiveness. These findings demonstrate that the PPAR genotype has a dramatic effect on the transcriptional targets of HS and support an expanded role for PPAR in the regulation of proteome maintenance genes after exposure to diverse forms of environmental stress including HS.
Analysis of the heat shock response in mouse liver reveals transcriptional dependence on the nuclear receptor peroxisome proliferator-activated receptor alpha (PPARalpha).
Sex, Age, Specimen part
View Samples