This SuperSeries is composed of the SubSeries listed below.
Variants of <i>DNMT3A</i> cause transcript-specific DNA methylation patterns and affect hematopoiesis.
Specimen part
View SamplesThe de novo DNA methyltransferase 3A (DNMT3A) plays a pivotal role in hematopoietic differentiation. In this study, we followed the hypothesis that alternative splicing of DNMT3A has characteristic epigenetic and functional sequels. Various transcripts of DNMT3A were either knocked down or overexpressed in human hematopoietic stem and progenitor cells resulting in complementary and transcript-specific DNA methylation (DNAm) and gene expression changes. Our results demonstrate that different splice variants of DNMT3A have distinct epigenetic and functional sequels.
Variants of <i>DNMT3A</i> cause transcript-specific DNA methylation patterns and affect hematopoiesis.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Integrated ordination of miRNA and mRNA expression profiles.
Specimen part
View SamplesSeveral studies have shown that negative and positive miRNA-mRNA correlations are symmetrically distributed. While negative correlations are consistent with a faster degradation of miRNA targets, the presence of positive correlations suggests bidirectional interactions between the two classes of molecules. However, a comprehensive study of miRNA and mRNA correlations is lacking. A homogeneous map of miRNA and mRNA relationships was obtained by multidimensional scaling (MDS) applied to a single matrix including both heterologous (miRNA-mRNA) and homologous (miRNA-miRNA and mRNA-mRNA) correlations.
Integrated ordination of miRNA and mRNA expression profiles.
Specimen part
View SamplesThe liver has inherent regenerative capacity via mitotic division of mature hepatocytes. However, if the hepatic loss is massive or mature hepatocyte proliferation is impaired by chronic liver injury, HSPC are activated to support liver regeneration. Access to liver tissue from 4 patients who underwent liver transplantation for hepatitis B virus (HBV)- associated acute liver failure (ALF) provided us with the opportunity to investigate the molecular mechanisms of liver regeneration in humans by means of gene expression profiling and immunohistochemistry (IHC). Gene expression profiling of 17 liver specimens from the 4 ALF cases and individual liver specimens from 10 liver donors documented a distinct gene signature for ALF. However, unsupervised multidimensional scaling and hierarchical clustering identified two-well defined clusters that segregated according to the histopathological severity, i.e. massive hepatic necrosis (MHN; 2 patients) and submassive hepatic necrosis (SHN; 2 patients). We found that ALF is characterized by a strong hepatic stem/progenitor cell (HSPC) gene signature, as also confirmed by IHC, along with ductular reaction, both of which are more prominent in MHN. Interestingly, no evidence of further lineage differentiation was seen in MHN, whereas in SHN we detected cells with hepatocyte-like morphology. Strikingly, ALF was associated with a strong tumorigenesis gene signature. MHN had the greatest upregulation of cancer stem cell genes (EpCAM, CK19 and CK7), whereas the most upregulated genes in SHN were related to cellular growth and proliferation (AKR1B10, NQO1, RRM2, SFN, TOP2A, CCNB1, CDC20, ANLN and KI67). The extent of liver necrosis correlated with an overriding fibrogenesis gene signature, reflecting the wound healing process. Conclusion: Our data provide evidence of marked HSPC cell activation and fibrogenesis in HBV-associated ALF, which positively correlate with the extent of liver necrosis. Moreover, we detected a strong tumorigenesis gene signature in ALF, which underlines the relationship between liver regeneration and liver cancer.
Liver regeneration signature in hepatitis B virus (HBV)-associated acute liver failure identified by gene expression profiling.
Specimen part, Disease, Disease stage, Subject
View SamplesRelative levels of RNA transcripts were compared between anterior and posterior wing bud thirds from stage HH24 normal and talpid3 mutant chicken embryos using chicken Affymetrix chips. Data collected with Affymetrix scanner was normalized using the Plier algorithm within the expression console package from Affymetrix and log2 transformed. 5 replicates of anterior third normal wing buds, 4 replicates of posterior third of normal wing buds and 4 replicates each of anterior and posterior thirds of talpid3 wing buds at stage HH24 were examined.
Identification of genes downstream of the Shh signalling in the developing chick wing and syn-expressed with Hoxd13 using microarray and 3D computational analysis.
Age, Specimen part
View SamplesPouchitis is a common complication for ulcerative colitis (UC) patients with ileal pouch-anal anastomosis (IPAA) surgery. Similarly to IBD, both innate host factors such as genetics, and environmental stimuli including the tissue-associated microbiome have been implicated in the pathogenesis. In this study, we make use of the IPAA model of inflammatory bowel disease (IBD) to carry out a study associating mucosal host gene expression with the microbiome and corresponding clinical outcomes.
Associations between host gene expression, the mucosal microbiome, and clinical outcome in the pelvic pouch of patients with inflammatory bowel disease.
Sex, Disease, Subject
View SamplesThe genetic mechanism governing the spatial patterning of teeth still remains to be elucidated. Sonic hedgehog (Shh) is one of key signaling molecules involved in the spatial patterning of teeth. By utilizing maternal transfer of 5E1 (an IgG1 monoclonal antibody against Shh protein) through the placenta to block Shh signaling, we investigated the changes in tooth patterning and in gene expression.
Interactions between Shh, Sostdc1 and Wnt signaling and a new feedback loop for spatial patterning of the teeth.
Specimen part, Time
View SamplesHepatitis B virus (HBV)-associated acute liver failure (ALF) is a dramatic clinical syndrome due to a sudden loss of hepatic cells leading to multiorgan failure. The mechanisms whereby HBV induces ALF are unknown. We used gene expression profiling to establish a molecular definition of hepatitis B virus (HBV)-associated ALF. Two patients who underwent liver transplantation for HBV-associated ALF were studied. Gene expression profiling was performed on 8 liver specimens obtained from the two patients with ALF (4 samples per liver) and individual liver specimens from 8 liver donors and normal livers from 11 patients who underwent resection for angioma. Statistical analyses were used to identify the signature genes of HBV-associated ALF. Multivariate permutation analysis identified 1,368 transcripts that were differentially expressed in ALF; 709 were up-regulated and 659 down-regulated. The most represented up-regulated transcripts were those involved in the immune response, whereas the most abundant down-regulated transcripts were those involved in metabolism and hepatic synthesis. ALF was characterized by overriding B-cell signature comprising genes related to mature B cells and plasma cells with abundant polyclonal expression of immunoglobulin genes. By contrast, there was a limited T-cell signature and up-regulation of several inhibitors of T-cell activation. Immunohistochemical analysis confirmed the prominent B-cell signature showing diffuse liver infiltration by plasma blasts and plasma cells with strong cytoplasmic staining for IgM and IgG, associated with a significant deposition of complement factors. Using phage display technology, we demonstrated that the molecular target of the massive intrahepatic antibody response is the hepatitis B core antigen (HBcAg). These data suggest that the humoral immunity may exert a primary role in the pathogenesis of HBV-associated ALF.
B cell gene signature with massive intrahepatic production of antibodies to hepatitis B core antigen in hepatitis B virus-associated acute liver failure.
Specimen part
View SamplesMicroRNAs have been demonstrated to be deregulated in multiple myeloma (MM). We have previously reported the downregulation of miR-214 in MM compared to normal plasma cells. In the present study, we have explored the functional role of miR-214 in myeloma pathogenesis. Ectopic expression of miR-214 reduced cell growth and induced apoptosis of myeloma cells. In order to identify the potential direct target genes of miR-214 which could be involved in the biological pathways regulated by this miRNA, gene expression profiling of H929 myeloma cell line transfected with precursor miR-214 was carried out. Functional analysis revealed significant enrichment for DNA replication, cell cycle phase and DNA binding. We show that miR-214 directly down-regulates the expression of PSMD10, which encodes the oncoprotein gankyrin, and ASF1B, a histone chaperone required for DNA replication, by binding to their 3'-UTR. In addition, gankyrin inhibition induced an increase of P53 mRNA levels and subsequent up-regulation in CDKN1A (p21Waf1/Cip1) and BAX transcripts, which are direct transcriptional targets of p53. In conclusion, we demonstrate that miR-214 function as a tumor suppressor in myeloma by a positive regulation of p53 and inhibition of DNA replication.
Restoration of microRNA-214 expression reduces growth of myeloma cells through positive regulation of P53 and inhibition of DNA replication.
Cell line
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