We used a whole genome approach to identify major functional gene categories (including xenobiotic transporters and metabolizing enzymes) whose expression depends on gestational age. STUDY DESIGN: We compared gene expression profiles of 1st (45-59 days) and 2nd trimester (109-115 days), and C-section term placentae. RESULTS: In 1st trimester placentae, genes related to cell cycle, DNA, aminoacids and carbohydrate metabolism were significantly overrepresented, while genes related to signal transduction were downregulated. In the organism defense category, we identified genes involved in chemical response, metabolism, and transport. Analysis of signal transduction pathways suggested, and subsequently confirmed independently, that the Wnt pathway was regulated by gestational age. CONCLUSIONS: Our study will serve as a reference database to gain insight into the regulation of gene expression in the developing placentae and, thus, allow comparisons with placentae from complicated pregnancies such as those in women experiencing gestational diabetes, pre-eclampsia and teratogenic sequelae.
Profiling gene expression in human placentae of different gestational ages: an OPRU Network and UW SCOR Study.
No sample metadata fields
View SamplesWomen are born with millions of primordial follicles which gradually decrease with increasing age and this irreversible supply of follicles completely exhausts at menopause. The fertility capacity of women diminishes in parallel with aging. The mechanisms for reproductive aging are not fully understood. In our recent work we observed a decline in BRCA1 mediated DNA repair in aging rat primordial follicles. To further understand the age-related molecular changes, we performed microarray gene expression analysis using total RNA extracted from immature (1820 days) and aged (400450 days) rat primordial follicles. The results of current microarray study revealed that there were 1011 (>1.5 fold, p<0.05) genes differentially expressed between two groups in which 422 genes were up-regulated and 589 genes were down-regulated in aged rat primordial follicles compared to immature. The gene ontology and pathway analysis of differentially expressed genes revealed a critical biological function such as cell cycle, oocyte meiosis, chromosomal stability, transcriptional activity, DNA replication and DNA repair were affected by age and this considerable difference in gene expression profiles may have adverse influence on oocyte quality. Our data provide information on the processes that may contribute to aging and age-related decline in fertility.
Age-related changes in gene expression patterns of immature and aged rat primordial follicles.
Specimen part
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 SamplesTo investigate the role of viral and host factors in HDV-associated HCC we carried out an integrated clinicopathological and gene expression study of tissue specimens and laser microdissected hepatocytes obtained at the time of liver transplantation from livers with HDV-HCC, HDV-cirrhosis without HCC, HCV-HCC and HBV-HCC. References to GSM series of HDV and HBV livers, already deposited in GEO, are included in this series. Part of data of HCV livers are a re-analysis of GSE series GSE69715 and GSE78737, the re-analyzed GSM is indicated in the 'description' column and with a link at the bottom of the page.
Molecular Signature and Mechanisms of Hepatitis D Virus-Associated Hepatocellular Carcinoma.
Sex, Specimen part, Disease, Disease stage, Subject
View SamplesTo investigate the role of viral and host factors in HDV-related HCC we analyzed the serum, tissue specimens and laser microdissected hepatocytes obtained at the time of liver transplantation from five patients with HDV-HCC. Livers of seven patients with HDV-cirrhosis without HCC were also analyzed. We carried out an integrated clinicopathological analysis and gene expression profiling,
Molecular Signature and Mechanisms of Hepatitis D Virus-Associated Hepatocellular Carcinoma.
Specimen part, Disease, Disease stage
View SamplesThe molecular mechanisms whereby hepatitis B virus (HBV) induces hepatocellular carcinoma (HCC) remain elusive. We used genomic and molecular techniques to investigate host-virus interactions by mapping the entire liver of patients with HCC. We compared the gene signature of whole liver tissue (WLT) versus laser capture-microdissected (LCM) hepatocytes with intrahepatic expression of HBV. Gene expression profiling was performed on up to 17 WLT specimens obtained at various distances from the tumor center in individual livers of 11 patients with HCC and on selected LCM samples. HBV biomarkers were determined by real-time PCR and confocal immunofluorescence. Analysis of 5 areas of the liver showed a sharp change in gene expression between the immediate perilesional area and tumor periphery that correlated with a significant decrease in the intrahepatic expression of HBsAg. The tumor was characterized by a large preponderance of down-regulated genes, mostly involved in the metabolism of lipid and fatty acid, glucose, amino acids and drugs, with down-regulation of pathways involved in the activation of PXR/RXR and PPARa/RXRa nuclear receptors, comprising PGC1 and FOXO1, two key regulators of the hepatic metabolic functions and HBV transcription. These findings were confirmed by gene expression of microdissected hepatocytes. However, LCM of malignant hepatocytes also revealed up-regulation of unique genes associated with cancer and signaling pathways, including two novel HCC-associated cancer testis antigen (CTA) genes, NUF2 and TTK. HCC-associated with HBV is characterized by a metabolism switch-off and by a significant reduction in HBsAg. LCM proved to be a critical tool to validate gene signatures associated with HCC and to identify genes that may play a role in hepatocarcinogenesis opening new perspectives for the discovery of novel diagnostic markers and therapeutic targets.
Viral expression and molecular profiling in liver tissue versus microdissected hepatocytes in hepatitis B virus-associated hepatocellular carcinoma.
Specimen part, Disease, Subject
View SamplesWe used phytochemical profiling techniques to generate a list of compounds present in each of 13 Equisetum arvense samples sourced globally. We used microarrays to detail the global programme of gene expression underlying the treatment of the model system Saccharomyces cerevisiae to a chosen number of these extracts. A thorough bioinformatic analysis was performed to identify the relationship between phytochemical and gene expression response profiles.
The Saccharomyces cerevisiae transcriptome as a mirror of phytochemical variation in complex extracts of Equisetum arvense from America, China, Europe and India.
No sample metadata fields
View SamplesTo investigate the role of viral and host factors in acute liver failure, we analyzed serum and multiple liver specimens obtained at the time of liver transplantation from four well-characterized patients. We carried out an integrated clinicopathological analysis, gene and microRNA expression profiling, next-generation sequencing, antibody-displaying phage libraries, and in vitro functional analysis of HBV variants.
Role of humoral immunity against hepatitis B virus core antigen in the pathogenesis of acute liver failure.
Specimen part, Disease, Disease stage
View SamplesAlthough host-parasitoid interactions are becoming well characterized at the organismal and cellular levels, much remains to be understood of the molecular bases for the host immune response and the parasitoids ability to defeat this immune response. Leptopilina boulardi and L. heterotoma, two closely related, highly infectious natural parasitoids of Drosophila melanogaster, appear to use very different infection strategies at the cellular level. Here, we further characterize cellular level differences in the infection characteristics of these two wasp species using newly derived, virulent inbred strains, and then use whole genome microarrays to compare the transcriptional response of Drosophila to each. While flies attacked by the melanogaster group specialist Leptopilina boulardi (strain Lb17) up-regulate numerous genes encoding proteolytic enzymes, components of the Toll and JAK/STAT pathways, and the melanization cascade as part of a combined cellular and humoral innate immune response, flies attacked by the generalist L. heterotoma (strain Lh14) do not appear to initiate an immune transcriptional response at the time points post-infection we assayed, perhaps due to the rapid venom-mediated lysis of host hemocytes (blood cells). Thus, the specialist parasitoid appears to invoke a full-blown immune response in the host, but suppresses and/or evades downstream components of this response. Given that activation of the host immune response likely depletes the energetic resources of the host, the specialists infection strategy seems relatively disadvantageous. However, we uncover the mechanism for one potentially important fitness tradeoff of the generalists highly immune suppressive infection strategy.
Contrasting infection strategies in generalist and specialist wasp parasitoids of Drosophila melanogaster.
No sample metadata fields
View SamplesWe applied a meta-analysis of datasets from seven different microarray studies on lung cancer for differentially expressed genes related to survival time (under 2 y and over 5 y). Systematic bias adjustment in the datasets was performed by distance-weighted discrimination (DWD). We identified a gene expression signature consisting of 64 genes that is highly predictive of which stage I lung cancer patients may benefit from more aggressive therapy.
A gene expression signature predicts survival of patients with stage I non-small cell lung cancer.
Sex
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