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GSE6045
Mus musculus
6 Downloadable Samples
Affymetrix Mouse Expression 430A Array (moe430a)
Description
Age-related hearing loss (AHL) is the progressive loss of auditory function with aging. The DBA/2J (DBA) mice have been used as a model of AHL and undergoes progressive, age-related hearing loss by 12 weeks of age. Here we analyzed cochlear gene expression of 7-week-old and 36-week-old DBA mice using microarrays. Auditory brainstem response (ABR) analysis confrimed that severe age-related hearing loss occured in 36-week-old mice, whereas moderate hearing loss occured in 7-week-old mice. Comprehensive gene expression analysis identified genes correlated with AHL and revealeed that 15 mitochondrial process categories, including mitochondrial electron transport chain, oxidative phosphorylation, respiratory chain complex I, respiratory chain complex IV, and respiratory chain complex V, were statistically associated with AHL-correlated genes in the cochlea of 36-week-old DBA mice, and that 25 genes encoding components of the mitochondrial respiratory chain (respiratory chain complex I, IV, and V) were significantly down-regulated in the cochlea. These observations provide evidence that AHL is associated with down-regulation of genes involved in the mitochondrial respiratory chain in the cochlea of DBA mice, and suggest that mitochondrial respiratory chain dysfunction may be a key feature of AHL in mammalian cochlea.
Publication Title
Genes encoding mitochondrial respiratory chain components are profoundly down-regulated with aging in the cochlea of DBA/2J mice.
Sample Metadata Fields
Sex, Specimen part
View Samples- Mus musculus
- 9 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Presbycusis is characterized by an age-related progressive decline of auditory function, and arises mainly from the degeneration of hair cells or spiral ganglion (SG) cells in the cochlea. Here we show that caloric restriction suppresses apoptotic cell death in the mouse cochlea and prevents late onset of presbycusis. Caloric restricted mice, which maintained body weight at the same level as that of young control (YC) mice, retained normal hearing and showed no cochlear degeneration. CR mice also showed significantly fewer TUNEL-positive staining cells and fewer cleaved caspase-3-positive staining cells relative to middle-age control (MC) mice. Microarray analysis revealed that CR down-regulated the expression of 28 proapoptotic genes, including Bak and Bim. Taken together, our findings suggest that loss of critical cells through apoptosis is an important mechanism of presbycusis in mammals, and that CR or staying lean can retard this process by suppressing apoptosis in the inner ear tissue.
Publication Title
Caloric restriction suppresses apoptotic cell death in the mammalian cochlea and leads to prevention of presbycusis.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Mus musculus
- 10 Downloadable Samples
- Affymetrix Mouse Genome 430 2.0 Array (mouse4302)
Description
Mitochondrial DNA (mtDNA) mutations may contribute to aging and age-related disorders. Previously, we created mice expressing a proofreading-deficient version of the mtDNA polymerase gamma (Polg) which accumulate age-related mtDNA mutations and display premature aging. Here we performed microarray gene expression profiling to identify mtDNA mutation-responsive genes in the cochlea of aged mitochondrial mutator mice. Age-related accumulation of mtDNA mutations was associated with transcriptional alternations consistent with reduced inner ear function, mitochondrial dysfunction, neurodegeneration, and reduced cell structural modulation. Hearing assessment and histopathological results confirmed that aged PolgD257A/D257A (D257A) mice exhibited moderate hearing loss and severe cochlear degenerations. Age-related accumulation of mtDNA mutations also resulted in alternations in gene expression consistent with induction of apoptosis, proteolysis, stress response, and reduced DNA repair. TUNEL (Terminal deoxynucleotidyl transferase-mediated dUTP nick-end labeling) assay confirmed that the cochleae from aged D257A mice showed significantly more TUNEL positive cells compared to wild-type (WT) mice. The levels of cleaved caspase-3 were also found to increase in the cochleae of aged D257A mice. These observations provide evidence that age-related accumulation of mtDNA mutations is associated with apoptotic cell death in aged cochlea. Our results provide the first global view of molecular events associated with mtDNA mutations in postmitotic tissue, and suggest that apoptosis is the major mechanism of mtDNA mediated cell death in the development of age-related hearing disorder.
Publication Title
The role of mtDNA mutations in the pathogenesis of age-related hearing loss in mice carrying a mutator DNA polymerase gamma.
Sample Metadata Fields
Sex, Age, Specimen part
View Samples- Mus musculus, Homo sapiens
- 8 Downloadable Samples
- Affymetrix Human Exon 1.0 ST Array [probe set (exon) version (huex10st)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Frequent Derepression of the Mesenchymal Transcription Factor Gene FOXC1 in Acute Myeloid Leukemia.
Sample Metadata Fields
Specimen part
View Samples- Homo sapiens
- 8 Downloadable Samples
Affymetrix Human Exon 1.0 ST Array [probe set (exon) version (huex10st)
Description
Bone marrow samples from normal adult male donors were collected into EDTA. Red cells were removed by ammonium chloride lysis. Leukocytes were washed in SM buffer and CD34+ cells were separated from CD34- cells using an AutoMACS device and anti-CD34 immunomagnetic beads (Miltenyi Biotec), according to manufacturers instructions. For mature cell populations, CD34- cells were FACS purified according to the following immunophenotypes, with 7-AAD used to exclude dead cells: Neutrophils: side scatter high CD15+ CD16+. Monocytes: side scatter low-intermediate CD14+ CD16- CD15-. See also Huang et al., 2014.
Publication Title
Frequent Derepression of the Mesenchymal Transcription Factor Gene FOXC1 in Acute Myeloid Leukemia.
Sample Metadata Fields
Specimen part
View Samples- Mus musculus
- 6 Downloadable Samples
- Affymetrix Mouse Gene 1.0 ST Array (mogene10st)
Description
Given the importance of deregulated phosphoinositide (PI) signaling in leukemic hematopoiesis, genes coding for proteins that regulate PI metabolism may have significant and as yet unappreciated roles in leukemia. We performed a targeted knockdown screen of PI modulator genes in human AML cells and identified candidates required to sustain proliferation or prevent apoptosis. One of these, the lipid kinase phosphatidylinositol-5-phosphate 4-kinase, type II, alpha (PIP4K2A) regulates cellular levels of phosphatidylinositol-5-phosphate (PtsIns5P) and phosphatidylinositol 4,5-bisphosphate (PtdIns(4,5)P2). We found PIP4K2A to be essential for the clonogenic and leukemia-initiating potential of human AML cells, and for the clonogenic potential of murine MLL-AF9 AML cells. Importantly, PIP4K2A is also required for the clonogenic potential of primary human AML cells. Its knockdown results in accumulation of the cyclin-dependent kinase inhibitors CDKN1A and CDKN1B, G1 cell cycle arrest and apoptosis. Both CDKN1A accumulation and apoptosis were partially dependent upon activation of the mTOR pathway. Critically, however, PIP4K2A knockdown in normal hematopoietic stem and progenitor cells, both murine and human, did not adversely impact either clonogenic or multilineage differentiation potential, indicating a selective dependency which we suggest may be the consequence of the regulation of different transcriptional programmes in normal versus malignant cells. Thus, PIP4K2A is a novel candidate therapeutic target in myeloid malignancy.
Publication Title
A targeted knockdown screen of genes coding for phosphoinositide modulators identifies PIP4K2A as required for acute myeloid leukemia cell proliferation and survival.
Sample Metadata Fields
Specimen part, Time
View Samples- Mus musculus
- 24 Downloadable Samples
NextSeq 500
Description
The Iroquois homeodomain transcription factor gene IRX3 is highly expressed in the developing nervous system, limb buds and heart. In adults, expression levels specify risk of obesity. We now report a significant functional role for IRX3 in human acute leukemia. While transcript levels are very low in normal human bone marrow cell populations, high level IRX3 expression is observed in ~30% of patients with acute myeloid leukemia (AML), ~50% of patients with T-acute lymphoblastic leukemia and ~20% of patients with B-acute lymphoblastic leukemia, typically in association with high levels of HOXA9. Expression of IRX3 alone was sufficient to immortalise murine bone marrow stem and progenitor cells, and induce T- and B-lineage leukemias in vivo with incomplete penetrance. IRX3 knockdown induced terminal differentiation of AML cells. Combined IRX3 and Hoxa9 expression in murine bone marrow stem and progenitor cells substantially enhanced the morphologic and phenotypic differentiation block of the resulting AMLs by comparison with Hoxa9-only leukemias, through suppression of a myelomonocytic program. Likewise, in cases of primary human AML, high IRX3 expression is associated with reduced myelomonocytic differentiation. Thus, tissue-inappropriate derepression of IRX3 modulates the cellular consequences of HOX gene expression to enhance differentiation block in human AML. Overall design: Murine acute myeloid leukemias - 3 samples from separate mice with AML initiated by HOXA9 and 3 samples from separate mice with AML initiated by HOXA9 and IRX3 coexpression
Publication Title
Derepression of the Iroquois Homeodomain Transcription Factor Gene IRX3 Confers Differentiation Block in Acute Leukemia.
Sample Metadata Fields
Specimen part, Cell line, Subject
View Samples- Triticum aestivum
- 77 Downloadable Samples
- Affymetrix Wheat Genome Array (wheat)
Description
The use of statistical tools established for the genetic analysis of quantitative traits can be applied to gene expression data. Quantitative trait loci (QTL) analysis can associate expression of genes or groups of genes with particular genomic regions and thereby identify regions that play a role in the regulation of gene expression. A segregating population of 41 doubled haploid (DH) lines from the hard red spring wheat cross RL4452 x AC Domain was used. This population had previously been mapped with microsatellites and includes a full QTL analysis for agronomic and seed quality traits. Expression analysis from 5 day post anthesis developing seed was conducted on 39 of the 41 DH lines using the Affymetrix wheat array. Expression analysis of developing seeds from field grown material identified 1,327 sequences represented by Affymetrix probe sets whose expression varied significantly between genotypes of the population. A sub-set of 378 transcripts were identified that each mapped to a single chromosome interval illustrating that major expression QTLs can be found in wheat. Genomic regions corresponding to multiple expression QTLs were identified that were coincident with previous identified seed quality trait QTL. These regions may be important regulatory regions governing economically important traits. Comparison of expression mapping data with physical mapping for a sub-set of sequences showed that both cis and trans acting expression QTLs were present.
Publication Title
Identifying regions of the wheat genome controlling seed development by mapping expression quantitative trait loci.
Sample Metadata Fields
No sample metadata fields
View Samples- Triticum aestivum
- 76 Downloadable Samples
- Affymetrix Wheat Genome Array (wheat)
Description
This SuperSeries is composed of the SubSeries listed below.
Publication Title
Identifying regions of the wheat genome controlling seed development by mapping expression quantitative trait loci.
Sample Metadata Fields
No sample metadata fields
View Samples- Triticum aestivum
- 72 Downloadable Samples
- Affymetrix Wheat Genome Array (wheat)
Description
The use of statistical tools established for the genetic analysis of quantitative traits can be applied to gene expression data. Quantitative trait loci (QTL) analysis can associate expression of genes or groups of genes with particular genomic regions and thereby identify regions that play a role in the regulation of gene expression. A segregating population of 41 doubled haploid (DH) lines from the hard red spring wheat cross RL4452 x AC Domain was used. This population had previously been mapped with microsatellites and includes a full QTL analysis for agronomic and seed quality traits. Expression analysis from 5 day post anthesis developing seed was conducted on 36 of the 41 DH lines using the Affymetrix wheat array. Expression analysis of developing seeds from field grown material in location 2 identified 10,280 sequences represented by Affymetrix probe sets whose expression varied significantly between genotypes of the population. Of these 1,455 were identified in the point location as well. A sub-set of 542 transcripts were identified that each mapped to a single chromosome interval illustrating that major expression QTLs can be found in wheat. Genomic regions corresponding to multiple expression QTLs were identified that were coincident with previous identified seed quality trait QTL. These regions may be important regulatory regions governing economically important traits. Comparison of expression mapping data with physical mapping for a sub-set of sequences showed that both cis and trans acting expression QTLs were present.
Publication Title
Identifying regions of the wheat genome controlling seed development by mapping expression quantitative trait loci.
Sample Metadata Fields
No sample metadata fields
View Samples