Protein synthesis belongs to the most energy consuming processes in the cell. Lowering oxygen tension below normal (hypoxia) causes a rapid inhibition of global mRNA translation due to the decreased availability of energy. Interestingly, subsets of mRNAs pursue active translation under such circumstances. In human fibrosarcoma cells (HT1080) exposed to prolonged hypoxia (36 h, 1% oxygen) we observed that transcripts are either increasingly or decreasingly associated with ribosomes localized at the endoplasmic reticulum (ER). In a global setting it turned out that only 31% of transcripts showing elevated total-RNA levels were also increasingly present at the ER in hypoxia. These genes, regulated by its expression as well as its ER-localization, belong to the gene ontologys hypoxia response, glycolysis and HIF-1 transcription factor network supporting the view of active mRNA translation at the ER during hypoxia. Interestingly, a large group of RNAs was found to be unchanged at the expression level, but translocate to the ER in hypoxia. Among these are transcripts encoding translation factors and >180 ncRNAs. In summary, we provide evidence that protein synthesis is favoured at the ER and, thus, partitioning of the transcriptome between cytoplasmic and ER associated ribosomes mediates adaptation of gene expression in hypoxia.
Hypoxia-induced gene expression results from selective mRNA partitioning to the endoplasmic reticulum.
Specimen part, Cell line
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YY1 is indispensable for Lgr5+ intestinal stem cell renewal.
Specimen part
View SamplesCrypts were isolated from either control or YY1f/f; Vil-Cre-ERT2 mice treated with tamoxifen for 4 days to induce knockout
YY1 is indispensable for Lgr5+ intestinal stem cell renewal.
Specimen part
View SamplesDuring late gestation, structures called villi extend into the intestinal lumen to dramatically increase the surface area of the intestinal epithelium, preparing the gut for the neonatal diet. Incomplete development of the intestine is the most common gastrointestinal complication in neonates, but the causes are unclear. We provide evidence that Yin-Yang1 (Yy1) is critical for intestinal villus development. YY1 loss in the developing endoderm had no apparent consequences until late gestation, after which the intestine differentiated poorly and exhibited severely stunted villi. Transcriptome analysis revealed that YY1 is required for mitochondrial gene expression, and ultrastructural analysis confirmed compromised mitochondrial integrity in the mutant intestine. We found increased oxidative phosphorylation gene expression at the onset of villus elongation, suggesting that aerobic respiration may function as a regulator of villus growth. Mitochondrial inhibitors blocked villus growth in a fashion similar to Yy1 loss, thus further linking oxidative phosphorylation with late-gestation intestinal development. Interestingly, we find necrotizing enterocolitis patients also exhibit decreased expression of oxidative phosphorylation genes. Our study highlights the still unappreciated role of metabolic regulation during organogenesis, and suggests it may contribute to neonatal gastrointestinal disorders.
A YY1-dependent increase in aerobic metabolism is indispensable for intestinal organogenesis.
Specimen part
View SamplesCell adhesion in plants is mediated predominantly by pectins, a group of complex cell wall associated polysaccharides. An Arabidopsis mutant, friable1 (frb1), was identified through a screen of T-DNA insertion lines that exhibited defective cell adhesion. Interestingly, the frb1 plants displayed both cell and organ dissociations and also ectopic organ fusions. The FRB1 gene encodes a Golgi-localized, plant specific protein with only weak sequence similarities to known proteins (DUF246). Unlike other cell adhesion deficient mutants, frb1 mutants do not have reduced levels of adhesion related cell wall polymers, such as pectins. Instead, FRB1 affects the abundance of galactose- and arabinose-containing oligosaccharides in the Golgi. Furthermore, frb1 mutants displayed alteration in pectin methylesterification, cell wall associated extensins and xyloglucan microstructure. We propose that abnormal FRB1 action has pleiotropic consequences on wall architecture, affecting both the extensin and pectin matrices, with consequent changes to the biomechanical properties of the wall and middle lamella, thereby influencing cell-cell adhesion.
The FRIABLE1 gene product affects cell adhesion in Arabidopsis.
Specimen part
View SamplesThe anticarcinogenic activity of hydroxytyrosyl ethyl ether (HTy-Et) compared to its precursor hydroxytyrosol (HTy) has been studied in human Caco-2 colon adenocarcinoma cells.
Hydroxytyrosyl ethyl ether exhibits stronger intestinal anticarcinogenic potency and effects on transcript profiles compared to hydroxytyrosol.
Specimen part, Disease, Disease stage, Cell line
View SamplesZNF521 is a multiple zinc finger transcription factor previously identified because abundantly and selectively expressed in normal CD34+ hematopoietic stem and progenitor cells. From microarray datasets, aberrant expression of ZNF521 has been reported in both pediatric and adult acute myeloid leukemia (AML) patients with MLL gene rearrangements. However, a proper validation of microarray data is lacking, likewise ZNF521 contribution in MLL-rearranged AML is still uncertain. In this study, we show that ZNF521 is significantly upregulated in MLL translocated AML patients from a large pediatric cohort, regardless of the type of MLL translocations such as MLL-AF9, MLL-ENL, MLL-AF10 and MLL-AF6 fusion genes. Our in vitro functional studies demonstrate that ZNF521 play a critical role in the maintenance of the undifferentiated state of MLL-rearranged cells. Furthermore, analysis of the ZNF521 gene promoter region shows that ZNF521 is a direct downstream target of both MLL-AF9 and MLL-ENL fusion proteins. Gene expression profiling of MLL-AF9-rearranged THP-1 cells after depletion of ZNF521 reveals correlation with several expression signatures including stem cell-like and MLL fusion dependent programs. These data suggest that MLL fusion proteins activate ZNF521 expression to maintain the undifferentiated state and contribute to leukemogenesis.
ZNF521 sustains the differentiation block in MLL-rearranged acute myeloid leukemia.
Specimen part, Cell line
View SamplesCD3-positive T cells were negatively isolated from 10 SLE patients and 9 healthy controls without SLE. All of the SLE samples and control samples were compared with one another to identify baseline differences in expression due to the disease. Next, T cell preparations from 4 of the control subjects were stimulated with either Nitric Oxide (NOC-18) 600 uM for 24hr or stimulated through CD3/CD28 for 24hr to determine which genes were responsive to these signaling mechanisms. Here, we show that activity of the mammalian target of rapamycin (mTOR), which is a sensor of the mitochondrial transmembrane potential, is increased in SLE T cells. Activation of mTOR was inducible by NO, a key trigger of MHP which in turn enhanced the expression of HRES-1/Rab4, a small GTPase that regulates recycling of surface receptors through early endosomes. Expression of HRES-1/Rab4 was increased in SLE T cells and, in accordance with its dominant impact on the endocytic recycling of CD4, it was inversely correlated with diminished CD4 expression. HRES-1/Rab4 over-expression was also inversely correlated with diminished TCR protein levels. Combined with follow up studies, these results suggest that activation of mTOR causes the loss of TCR in lupus T cells through HRES-1/Rab4-dependent lysosomal degradation.
Activation of mammalian target of rapamycin controls the loss of TCRzeta in lupus T cells through HRES-1/Rab4-regulated lysosomal degradation.
No sample metadata fields
View SamplesTo determine the effects of depleting TIP60, CDK8, or HIF1A on the transcriptional response to hypoxia, we performed RNAseq analysis of four HCT116 colorectal carcinoma cell lines (shNT, HIF1A-/-, shTIP60 and shCDK8) in normoxic and hypoxic (24hrs, 1% O2) conditions. Overall design: PolyA RNA for two independent biological replicates was purified from HCT116 cells stably expressing an shRNA against a non-targeting control (shNT), TIP60 (shTIP60) or CDK8 (shCDK8), or genetically deleted HIF1A (HIF1A-/-) subjected to 24hrs 1% O2 (hypoxia) or maintained under ambient oxygen (21%; normoxia) was sequenced on the Ion Torrent platform. Reads were aligned to the human genome and gene-level counts were used for differential expression analysis.
The TIP60 Complex Is a Conserved Coactivator of HIF1A.
No sample metadata fields
View SamplesWe have develop a proteogenomics-based approach for identification of human MHC class I-associated peptides, including those deriving from polymorphisms, mutations and non-canonical reading frames Overall design: RNA-seq of human EBV-infected B lymphoblasts derived from peripheral blood mononuclear cells from volunteers Please note that GSM1641204 and GSM1641205 are reanalyzed and duplicated sample records of GSM1186811 and GSM1186812, respectively, for the convenient retrieval of the complete raw data from SRA
Global proteogenomic analysis of human MHC class I-associated peptides derived from non-canonical reading frames.
No sample metadata fields
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