Filters
Technology
Platform
GSE12160
Drosophila melanogaster
24 Downloadable Samples
Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
One of the critical substances that mammals highly regulate via the respiratory, cardiovascular and neurologic systems is O2. Both low and high O2 levels can induce major morbidities as well as mortality. Indeed, O2 has been often considered as both an elixir and a poison in humans. In current study, we have used an experimental selection approach to generate Drosophila strains that are tolerant to severe hyperoxic environment. Gene expression profiling is then applied to investigate the mechanisms underlying hyperoxia tolerance in the newly generated strains.
Publication Title
Experimental selection for Drosophila survival in extremely high O2 environments.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 9 Downloadable Samples
- Illumina MouseWG-6 v2.0 expression beadchip
Description
Stem cells are a potential key strategy for treating neurodegenerative diseases in which the generation of new neurons is critical. A better understanding of the characteristics and molecular properties of neural stem cells (NSC) and differentiated neurons can help in assessing neuronal maturity and possibly in devising better therapeutic strategies. We have therefore performed an in-depth gene expression profiling study of the C17.2 NSC line and primary neurons (PN) derived from embryonic mouse brains. Microarray analysis revealed a neuron-specific gene expression signature that distinguishes PN from NSCs, with elevated levels of transcripts involved in neuronal functions such as neurite development, axon guidance, in PN. The same comparison revealed decreased levels of multiple cytokine transcripts such as IFN, TNF, TGF, and IL. Among the differentially expressed genes, we found a statistically significant enrichment of genes in the ephrin, neurotrophin, CDK5 and actin pathways which control multiple neuronal-specific functions. Furthermore, genes involved in cell cycle were among the most significantly changed in PN. In order to better understand the role of cell cycle arrest in mediating NSCs differentiation, we blocked the cell cycle of NSCs with Mitomycin C (MMC) and examined cellular morphology and gene expression signatures. Although these MMC-treated NSCs displayed a neuronal morphology and expressed some neuronal differentiation marker genes, their gene expression patterns was very different from primary neurons. We conclude that: 1) Fully differentiated primary neurons display a specific neuronal gene expression signature; 2) cell-cycle block in NSC does not induce the formation of fully differentiated neurons; 3) Cytokines such as IFN, TNF, TGF and IL are part of normal NSC function and/or physiology; 4) Signaling pathways of ephrin, neurotrophin, CDK5 and actin, related to major neuronal features, are dynamically enriched in genes showing changes in expression level.
Publication Title
Identification of a neuronal gene expression signature: role of cell cycle arrest in murine neuronal differentiation in vitro.
Sample Metadata Fields
Sex, Specimen part, Cell line
View Samples- Mus musculus
- 9 Downloadable Samples
- Illumina MouseWG-6 v2.0 expression beadchip
Description
Multiple diseases are associated with a pathological hypoxia in the brain, resulting in various neurological sequalae. Understanding the response to hypoxia of neurons and neural stem cells (NSCs) will help devise better therapeutic strategies. We have exposed primary neurons (PN) and neural stem cells to 1% O2. Both cell types survived well, and neurons showed no obvious morphological changes. The NSCs, however, became fusiform, and displayed a population of cells with accelerated transition in cell cycle. Gene expression profile through microarray analysis revealed major differences in response to hypoxia between NSC and PN. Not only the number of genes significantly changes was ~five-fold higher in NSC, but the types of genes involved and the direction of change was quite different. In particular, NSCs up-regulated multiple growth factors and down-regulated most other cytokines and metalloproteases , while PN down-regulated most neuronal-specific genes, up-regulated growth factors, with no major effect on cytokines. We conclude that hypoxia 1- accelerates cell cycle transition of NSC in a post-transcriptional fashion ; 2-affects cytokines in NSC but not in neurons; 3-result in up-regulation of multiple growth factors in NSC and PN; and 4-suppresses neuronal specific functions.
Publication Title
No associated publication
Sample Metadata Fields
Sex, Specimen part, Cell line
View Samples- Drosophila melanogaster
- 9 Downloadable Samples
- Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
Background: Constant hypoxia (CH) and intermittent hypoxia (IH) occur during several pathological conditions such as asthma and obstructive sleep apnea. Our research is focused on understanding the molecular mechanisms that lead to injury or adaptation to hypoxic stress using Drosophila as a model system. Our current genome-wide study is designed to investigate gene expression changes and identify protective mechanism(s) in D. melanogaster after exposure to severe (1% O2) intermittent or constant hypoxia.
Publication Title
Distinct mechanisms underlying tolerance to intermittent and constant hypoxia in Drosophila melanogaster.
Sample Metadata Fields
Specimen part
View Samples- Drosophila melanogaster
- 6 Downloadable Samples
- Affymetrix Drosophila Genome 2.0 Array (drosophila2)
Description
It is well appreciated that reactive oxygen species (ROS) are deleterious to mammals, including humans, especially when generated in abnormally large quantities from cellular metabolism. Whereas the mechanisms leading to the production of ROS are rather well delineated, the mechanisms underlying tissue susceptibility or tolerance to oxidant stress remain elusive. Through an experimental selection over many generations, we have previously generated Drosophila melanogaster flies that tolerate tremendous oxidant stress and have shown that the family of antimicrobial peptides (AMP) is over-represented in these tolerant flies. Furthermore, we have also demonstrated that overexpression of even one AMP at a time (e.g. Diptericin) allows wild type flies to survive much better in hyperoxia. In the current study, we used a number of experimental approaches to investigate the potential mechanisms underlying hyperoxia tolerance in flies with antimicrobial peptide overexpression. We demonstrate that flies with Diptericin overexpression resist oxidative stress by increasing antioxidant enzyme activities and preventing an increase in ROS level after hyperoxia. Depleting the GSH pool using buthionine sulfoximine limits fly survival, thus confirming that enhanced survival observed in these flies is related to improved redox homeostasis. We conclude that a) AMPs play an important role in tolerance to oxidant stress; b) overexpression of Diptericin changes the cellular redox balance between oxidant and antioxidant, and c) this change in redox balance plays an important role in survival in hyperoxia.
Publication Title
Antimicrobial peptides increase tolerance to oxidant stress in Drosophila melanogaster.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus, Homo sapiens
- 71 Downloadable Samples
Illumina HumanHT-12 V4.0 expression beadchip, Illumina MouseRef-8 v2.0 expression beadchip
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Comparative analysis of mouse and human placentae across gestation reveals species-specific regulators of placental development.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 54 Downloadable Samples
- Illumina MouseRef-8 v2.0 expression beadchip
Description
In this study, we compared the genome-wide transcriptome of mouse and human placentas across gestation to identify species-specific signatures of early development. We also compared human placental signatures to purified primary cytotrophoblasts (CTB) isolated from placentae at different gestational age.
Publication Title
Comparative analysis of mouse and human placentae across gestation reveals species-specific regulators of placental development.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 17 Downloadable Samples
- Illumina HumanHT-12 V4.0 expression beadchip, Illumina MouseRef-8 v2.0 expression beadchip
Description
In this study, we compared the genome-wide transcriptome of mouse and human placentas across gestation to identify species-specific signatures of early development. We also compared human placental signatures to purified primary cytotrophoblasts (CTB) isolated from placentae at different gestational age.
Publication Title
Comparative analysis of mouse and human placentae across gestation reveals species-specific regulators of placental development.
Sample Metadata Fields
No sample metadata fields
View Samples- Homo sapiens
- 39 Downloadable Samples
- Affymetrix Human Genome U133A 2.0 Array (hgu133a2)
Description
Cerebral palsy is primarily an upper motor neuron disease that results in a spectrum of progressive movement disorders. Secondary to the neurological lesion, muscles from patients with cerebral palsy are often spastic and form debilitating contractures that limit range of motion and joint function. With no genetic component, the pathology of skeletal muscle in cerebral palsy is a response to aberrant neurological input in ways that are not fully understood. This study was designed to gain further understanding of the skeletal muscle response to cerebral palsy using microarrays and correlating the transcriptional data with functional measures. Hamstring biopsies from gracilis and semitendinosus muscles were obtained from a cohort of patients with cerebral palsy (n=10) and typically developing patients (n=10) undergoing surgery. Affymetrix HG-U133A 2.0 chips (n=40) were used and expression data was verified for 6 transcripts using quantitative real-time PCR, as well as for two genes not on the microarray. Chips were clustered based on their expression and those from patients with cerebral palsy clustered separately. Significant genes were determined conservatively based on the overlap of three summarization algorithms (n=1,398). Significantly altered genes were analyzed for over-representation among gene ontologies, transcription factors, pathways, microRNA and muscle specific networks. These results centered on an increase in extracellular matrix expression in cerebral palsy as well as a decrease in metabolism and ubiquitin ligase activity. The increase in extracellular matrix products was correlated with mechanical measures demonstrating the importance in disability. These data lay a framework for further studies and novel therapies.
Publication Title
Transcriptional abnormalities of hamstring muscle contractures in children with cerebral palsy.
Sample Metadata Fields
Sex, Age, Disease, Subject
View Samples- Homo sapiens
- 35 Downloadable Samples
- Affymetrix Human Gene 1.0 ST Array (hugene10st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Modeling non-syndromic autism and the impact of TRPC6 disruption in human neurons.
Sample Metadata Fields
Specimen part
View Samples