Menisci play a vital role in load transmission, shock absorption and joint stability. The current dogma is that the menisci simply protects the cartilage and play no role in osteoarthritis (OA) unless they are injured. However, there is increasing evidence suggesting that OA menisci may not merely be bystanders in the disease process of OA. This study sought: 1) to determine the prevalence of meniscal degeneration in OA patients, 2) to examine gene expression in OA meniscal cells compared to normal control meniscal cells, and 3) to test the hypothesis that OA meniscal cells are different from normal meniscal cells.
Analysis of meniscal degeneration and meniscal gene expression.
Specimen part
View SamplesMiR-221 overexpression leads to activation of apoptosis, growth arrest and reduced invasivness in PCa cells. Interaction of miR-221 with potential target genes was analyzed by a genome wide expression profiling.. Regulation of selected genes and proteins identified in the gene array analysis was confirmed by Real Time RT-PCR assay (IRF1, IRF2 SOCS3, STAT1), and Western Blotting. In total, 282 genes were upregulated and 64 downregulated based on a more than 2-fold difference to untransfected PC-3 cells. Regulated genes are involved in apoptosis, hemostasis, oxidative stress response, tumorigenesis and inflammation. We confirmed dysregulation of IRF-2 SOCS3, STAT1,IRF9. These results indicate that miR-221 overexpression might lead to activation of the JAK/STAT pathway and downregulation of miR-221 might contribute to tumorigenesis in PCa cells.
Survival in patients with high-risk prostate cancer is predicted by miR-221, which regulates proliferation, apoptosis, and invasion of prostate cancer cells by inhibiting IRF2 and SOCS3.
Cell line
View SamplesHuman adenovirus 5 encodes a small set of miRNAs, which are generated by DICER-mediated processing of 2 larger precursors, the so-called virus-associated RNAs I and II. To identify targets of one of the major miRNA isoforms derived from virus-associated RNAI (mivaRNAI-137), we isolated Argonaute complexes of mivaRNAI-137-transfected cells and analyzed co-purifying RNAs by microarray analysis. RNAs enriched in Argonaute complexes of mivaRNAI-137-transfected cells compared to cells transfected with a control siRNA were identified and subjected to further validation. RNAs specifically associated with Argonaute-containining complexes of adenovirus 5-infected cells were identified as well.
Identification of RISC-associated adenoviral microRNAs, a subset of their direct targets, and global changes in the targetome upon lytic adenovirus 5 infection.
Cell line
View SamplesNeuronal function critically depends on coordinated subcellular distribution of mRNAs. Disturbed mRNA processing and axonal transport has been found in spinal muscular atrophy and could be causative for dysfunction and degeneration of motoneurons. Despite the advances made in characterizing the transport mechanisms of several axonal mRNAs, an unbiased approach to identify the axonal repertoire of mRNAs in healthy and degenerating motoneurons has been lacking. Here we used compartmentalized microfluidic chambers to investigate the somatodendritic and axonal mRNA content of cultured motoneurons by microarray analysis. In axons, transcripts related to protein synthesis and energy production were enriched relative to the somatodendritic compartment. Knockdown of Smn, the protein deficient in spinal muscular atrophy, produced a large number of transcript alterations in both compartments. Transcripts related to immune functions, including MHC class I genes, and with roles in RNA splicing were upregulated in the somatodendritic compartment. On the axonal side, transcripts associated with axon growth and synaptic activity were downregulated. These alterations provide evidence that subcellular localization of transcripts with axonal functions as well as regulation of specific transcripts with nonautonomous functions is disturbed in Smn-deficient motoneurons, most likely contributing to the pathophysiology of spinal muscular atrophy.
Subcellular transcriptome alterations in a cell culture model of spinal muscular atrophy point to widespread defects in axonal growth and presynaptic differentiation.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
BCAT1 restricts αKG levels in AML stem cells leading to IDHmut-like DNA hypermethylation.
Cell line, Treatment
View SamplesThe branched chain amino acid (BCAA) pathway and high levels of BCAA transaminase 1 (BCAT1) have recently been associated with aggressiveness in several cancer entities. However, the mechanistic role of BCAT1 in this process remains largely uncertain. By performing high-resolution proteomic analysis of human acute myeloid leukaemia (AML) stem cell (LSC) and non-LSC populations, we found the BCAA pathway enriched and BCAT1 overexpressed in LSCs. We show that BCAT1, which transfers -amino groups from BCAAs to -ketoglutarate (KG), is a critical regulator of intracellular KG homeostasis. Next to its role in the tricarboxylic acid (TCA) cycle KG is an essential co-factor for KG-dependent dioxygenases such as EGLN1 and the TET family of DNA demethylases. Knockdown of BCAT1 in leukaemia cells caused accumulation of KG leading to HIF1a protein degradation mediated by EGLN1. This resulted in a growth and survival defect and abrogated leukaemia-initiating potential. In contrast, overexpression (OE) of BCAT1 in leukaemia cells decreased intracellular KG levels and caused DNA hypermethylation via altered TET activity. BCAT1high AMLs displayed a DNA hypermethylation phenotype similar to cases carrying mutant isocitrate dehydrogenase (IDHmut), in which TET2 is inhibited by the oncometabolite 2-hydroxyglutarate. High levels of BCAT1 strongly correlate with shorter overall survival in IDHwtTET2wt, but not IDHmut or TET2mut AMLs. Gene sets characteristic for IDHmut AMLs were enriched in IDHwtTETwtBCAT1high patient samples. BCAT1high AMLs showed robust enrichment for LSC signatures and paired sample analysis revealed a significant increase of BCAT1 levels upon disease relapse. In summary, by limiting intracellular KG, BCAT1 links BCAA catabolism to HIF1a stability and regulation of the epigenomic landscape. Our results suggest the BCAA-BCAT1-KG pathway as a therapeutic target to compromise LSC function in IDHwtTET2wt AML patients.
BCAT1 restricts αKG levels in AML stem cells leading to IDHmut-like DNA hypermethylation.
Treatment
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Mechanisms of epigenetic and cell-type specific regulation of Hey target genes in ES cells and cardiomyocytes.
Specimen part
View SamplesWe used an in vitro cardiomyocyte differentiation system with inducible Hey1 or Hey2 expression to study target gene regulation in cardiomyocytes (CM) generated from murine embryonic stem cells (ESC). The effects of Hey1 and Hey2 are largely redundant, but cell type specific. The number of regulated genes is comparable between ESC and CM, but the total number of binding sites is much higher, especially in ESC, targeting mainly genes involved in transcriptional regulation and developmental processes. Repression by Hey generally correlates with the extent of Hey-binding to target promoters, subsequent Hdac recruitment and lower histone acetylation. Functionally, treatment with the Hdac inhibitor TSA abolished Hey target gene regulation. However, in CM the repressive effect of Hey-binding is lost for a subset of genes. These lack Hey-dependent histone deacetylation in CM and are enriched for binding sites of cardiac specific activators like Srf, Nkx2-5, and Gata4.
Mechanisms of epigenetic and cell-type specific regulation of Hey target genes in ES cells and cardiomyocytes.
No sample metadata fields
View SamplesWe used an in vitro cardiomyocyte differentiation system with inducible Hey1 or Hey2 expression to study target gene regulation in cardiomyocytes (CM) generated from murine embryonic stem cells (ESC). The effects of Hey1 and Hey2 are largely redundant, but cell type specific. The number of regulated genes is comparable between ESC and CM, but the total number of binding sites is much higher, especially in ESC, targeting mainly genes involved in transcriptional regulation and developmental processes. Repression by Hey generally correlates with the extent of Hey-binding to target promoters, subsequent Hdac recruitment and lower histone acetylation. Functionally, treatment with the Hdac inhibitor TSA abolished Hey target gene regulation. However, in CM the repressive effect of Hey-binding is lost for a subset of genes. These lack Hey-dependent histone deacetylation in CM and are enriched for binding sites of cardiac specific activators like Srf, Nkx2-5, and Gata4. Overall design: ES cells and cardiomyocytes with Hey1 or Hey2 overexpression were compared to control cells
Mechanisms of epigenetic and cell-type specific regulation of Hey target genes in ES cells and cardiomyocytes.
No sample metadata fields
View SamplesEarly onset sepsis due to Group B streptococcus (GBS) leads to neonatal morbidity, increased mortality and long term neurological deficencies. Interaction between septicemic GBS and confluent monlayers of human coronary artery endothelial cells (HCAEC) was analyzed by a genome wide expression profiling. Regulation of selected genes and proteins identified in the gene array analysis was confirmed by Real Time RT-PCR assay (Granulocyte chemotactic protein 2 (CXCL6)), ELISA (Urokinase, Cyclooxygenase 2 (COX2), Granulocyte chemotactic protein 1 (IL8)) and Western Blotting (Heme oxygenase1, BCL2 interacting protein (BIM)) at various time points between 4 and 24 hours. In total, 124 genes were differentially regulated (89 upregulated, 35 downregulated) based on a more than 3-fold difference to unstimulated HCAEC. Regulated genes are involved in apoptosis, hemostasis, oxidative stress response, infection and inflammation. We confirmed upregulation of urokinase (UPA), COX2, HMOX1 and BCL2 interacting protein and downregulation of CXCL6 and IL8. These results indicate that GBS infection might lead to impaired function of the innate immune system and might contribute to hemorrhagic and inflammatory complications during GBS sepsis.
Infection of human coronary artery endothelial cells by group B streptococcus contributes to dysregulation of apoptosis, hemostasis, and innate immune responses.
No sample metadata fields
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