Limited access to large samples and independent replication cohorts precludes genome-wide association (GWA) studies of rare but complex traits. To localize candidate genes in an on-going study utilizing family-based GWA, a novel exploratory analysis was first tested on 1,774 major histocompatibility complex single nucleotide polymorphisms (SNPs) in 240 DNA samples from 80 children with primary liver transplantation (LTx), and their biological parents. Genotyping was performed using the Illumina HumHap550k SNP BeadArray; the genotype calls for the 1813 SNPs in the MHC region are provided in the genotype_data.zip supplementary file linked to this series (see README file in the zip archive for more information).
Genetic variants in major histocompatibility complex-linked genes associate with pediatric liver transplant rejection.
No sample metadata fields
View SamplesThe Affymetrix Human Exon 1.0 ST array was used to measure differential splicing patterns in archived RNA isolated from 26 of 80 children (11 Rejectors and 15 Non-Rejectors). The exon-level probe summaries reported in this series were computed using the Affymetrix Power Tools (APT) software and 'rma-sketch' normalization method.
Genetic variants in major histocompatibility complex-linked genes associate with pediatric liver transplant rejection.
No sample metadata fields
View SamplesThe Affymetrix Human Exon 1.0 ST array was used to measure differential splicing patterns in archived RNA isolated from 26 of 80 children (11 Rejectors and 15 Non-Rejectors). The gene-level probe summaries reported in this series were computed using the Affymetrix Power Tools (APT) software and 'rma-sketch' normalization method.
Genetic variants in major histocompatibility complex-linked genes associate with pediatric liver transplant rejection.
No sample metadata fields
View SamplesColon gene expression in human IBD. The three major clinical subsets of Inflammatory Bowel Disease (IBD) include colon-only Crohn's Disease (CD), ileo-colonic CD, and Ulcerative Colitis (UC). These experiments tested differential colon gene expression in these three types of IBD, relative to healthy control samples, and the local degree of mucosal inflammation as measured by the CD Histological Index of Severity (CDHIS). Colon biopsy samples were obtained from IBD patients at diagnosis and during therapy, and healthy controls. The global pattern of gene expression was determined using GeneSpring software, with a focus upon candidate genes identified in a recent genome wide association study in pediatric onset IBD. Data suggested that two of these candidate genes are up regulated in pediatric IBD, partially influenced by local mucosal inflammation.
Loci on 20q13 and 21q22 are associated with pediatric-onset inflammatory bowel disease.
No sample metadata fields
View SamplesThe response of cells to hypoxia is characterised by co-ordinated regulation of many genes. Studies of the regulation of the expression of many of these genes by oxygen has implicated a role for the heterodimeric transcription factor hypoxia inducible factor (HIF). The mechanism of oxygen sensing which controls this heterodimeric factor is via oxygen dependent prolyl and asparaginyl hydroxylation by specific 2-oxoglutarate dependent dioxygenases (PHD1, PHD2, PHD3 and FIH-1). Whilst HIF appears to have a major role in hypoxic regulation of gene expression, it is unclear to what extent other transcriptional mechanisms are also involved in the response to hypoxia. The extent to which 2-oxoglutarate dependent dioxygenases are responsible for the oxygen sensing mechanism in HIF-independent hypoxic gene regulation is also unclear. Both the prolyl and asparaginyl hydroxylases can be inhibited by dimethyloxalylglycine (DMOG). Such inhibition can produce activation of the HIF system with enhanced transcription of target genes and might have a role in the therapy of ischaemic disease. We have examined the extent to which the HIF system contributes to the regulation of gene expression by hypoxia, to what extent 2-oxoglutarate dependent dioxygenase inhibitor can mimic the hypoxic response and the nature of the global transcriptional response to hypoxia. We have utilised microarray assays of mRNA abundance to examine the gene expression changes in response to hypoxia and to DMOG. We demonstrate a large number of hypoxically regulated genes, both known and novel, and find a surprisingly high level of mimicry of the hypoxic response by use of the 2-oxoglutarate dependent dioxygenase inhibitor, dimethyloxalylglycine. We have also used microarray analysis of cells treated with small interfering RNA (siRNA) targeting HIF-1alpha and HIF-2alpha to demonstrate the differing contributions of each transcription factor to the transcriptional response to hypoxia. Candidate transcripts were confirmed using an independent microarray platform and real-time PCR. The results emphasise the critical role of the HIF system in the hypoxic response, whilst indicating the dominance of HIF-1alpha and defining genes that only respond to HIF-2alpha.
Concordant regulation of gene expression by hypoxia and 2-oxoglutarate-dependent dioxygenase inhibition: the role of HIF-1alpha, HIF-2alpha, and other pathways.
No sample metadata fields
View SamplesThe aim of the study is to evaluate oxygen regulated gene expression in human peripheral blood lymphocytes using microarray analysis.
Variations within oxygen-regulated gene expression in humans.
No sample metadata fields
View SamplesPRC, a member of the PGC-1 coactivator family, is responsive to serum growth factors and up regulated in proliferating cells. Here, we investigated its in vivo role by stably silencing PRC expression with two different short hairpin RNAs (shRNA#1 and shRNA#4) that were lentivirally introduced into U2OS cells. ShRNA#1 transductants exhibited nearly complete knockdown of PRC protein whereas shRNA#4 transductants expressed PRC protein at approximately 15 percent of the control level. Complete PRC silencing by shRNA#1 resulted in a severe inhibition of respiratory growth, reduced expression of respiratory protein subunits from complexes I, II, III and IV, markedly lower complex I and IV respiratory enzyme levels and diminished mitochondrial ATP production. Surprisingly, shRNA#1 transductants exhibited a striking proliferation of abnormal mitochondria that were devoid of organized cristae and displayed severe membrane abnormalities. Although shRNA#4 transductants had normal respiratory subunit expression and a moderately diminished respiratory growth rate, both transductants showed markedly reduced growth on glucose accompanied by inhibition of G1/S cell cycle progression. Microarray analysis revealed striking overlaps in the genes affected by PRC silencing in the two transductants and the functional identities of these overlapping genes were consistent with the observed mitochondrial and cell growth phenotypes. The consistency between phenotype and PRC expression levels in the two independent transductant lines argues that the defects result from PRC silencing and not from off target effects. These results support a role for PRC in the integration of pathways directing mitochondrial respiratory function and cell growth.
Short hairpin RNA-mediated silencing of PRC (PGC-1-related coactivator) results in a severe respiratory chain deficiency associated with the proliferation of aberrant mitochondria.
No sample metadata fields
View SamplesDicamba is an auxin-like herbicide that can stimulate the production of ethylene and ABA biosynthesis. The subsequent stomatal closure and build-up of reactive oxygen species is hypothesized to contribute to plant death.
Mutant analysis in Arabidopsis provides insight into the molecular mode of action of the auxinic herbicide dicamba.
Specimen part
View SamplesHuman blood monocytes were differentiated over six days with either 100 ng/ml M-CSF or 1 umol/l CXCL4
CXC chemokine ligand 4 induces a unique transcriptome in monocyte-derived macrophages.
Specimen part
View SamplesNatural killer (NKT) T cells exhibit tissue distribution, surface phenotype, and functional responses that are strikingly different from those of conventional T cells. The transcription factor PLZF is responsible for most of these properties, as its ectopic expression in conventional T cells is sufficient to confer to them an NKT-like phenotype. The molecular program downstream of PLZF, however, is largely unexplored.
PLZF Controls the Expression of a Limited Number of Genes Essential for NKT Cell Function.
Sex, Specimen part
View Samples