CD24, or heat stable antigen, is a cell surface sialoglycoprotein expressed on immature cells that disappears after the cells have reached their final differentiation stage. CD24 may be important in human embryonic kidney epithelial cell differentiation. In mice, CD24 expression is up-regulated in the early metanephros and localized to developing epithelial structures but the role and expression of CD24 in the developing human kidney has not been well described. In normal human fetal kidneys from 8 to 38 weeks gestation, CD24 expression was up-regulated and restricted to the early epithelial aggregates of the metanephric blastema and to the committed proliferating tubular epithelia of the S-shape nephron; however individual CD24+ cells were identified in the interstitium of later gestation and postnatal kidneys. In freshly isolated cells, FACS analysis demonstrated distinct CD24+ and CD24+133+ cell populations, constituting up to 16% and 14% respectively of the total cells analyzed. Isolated and expanded CD24+ clones displayed features of an epithelial progenitor cell line. Early fetal urinary tract obstruction resulted in an upregulation of CD24 expression, both in developing epithelial structures of early gestation kidneys and in the cells of the injured tubular epithelium of the later gestation kidneys. These results highlight the cell specific expression of CD24 in the developing human kidney and dysregulation in fetal urinary tract obstruction.
Ontogeny of CD24 in the human kidney.
Age, Specimen part
View SamplesTo address the functional role of MOF in mammalian X upregulation, male and female mouse ES cells were transfected with a mixture of three small interfering RNA duplexes, each of which targets a different region of Mof mRNA. We found that MOF knockdown in mouse ES cells caused a greater drop in expression of X-linked genes compared to autosomal genes, as measured by expression array analyses. The strongest effect was observed on medium-expressed X-linked genes.
Mammalian X upregulation is associated with enhanced transcription initiation, RNA half-life, and MOF-mediated H4K16 acetylation.
Specimen part, Treatment
View SamplesAffymetrix 430 2.0 mouse arrays were used for expression analyses in undifferentiated and differentiated PGK12.1 ES cells. We found that the X:autosome expression ratios calculated from the mean expression values of X-linked and autosomal genes from microarrays was ~1.4 in undifferentiated female ES cells and then decreased to 1.2 in PGK12.1 cells after 15-day embryoid body differentiation. Thus, a substantial level of X upregulation is already evident in these ES cells prior to differentiation.
Mammalian X upregulation is associated with enhanced transcription initiation, RNA half-life, and MOF-mediated H4K16 acetylation.
Specimen part
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Transcriptome-wide miR-155 binding map reveals widespread noncanonical microRNA targeting.
Specimen part
View SamplesmicroRNAs (miRNAs) are essential components of gene regulation, but identification of miRNA targets remains a major challenge. Most target prediction and discovery relies on perfect complementarity of the miRNA seed to the 3 untranslated region (UTR). However, it is unclear to what extent miRNAs target sites without seed matches. Here, we performed a transcriptome-wide identification of the endogenous targets of a single miRNAmiR-155in a genetically controlled manner. We found that approximately forty percent of miR-155-dependent Argonaute binding occurs at sites without perfect seed matches. The majority of these non-canonical sites feature extensive complementarity to the miRNA seed with one mismatch. These non-canonical sites confer regulation of gene expression albeit less potently than canonical sites. Thus, non-canonical miRNA binding sites are widespread, often contain seed-like motifs, and can regulate gene expression, generating a continuum of targeting and regulation.
Transcriptome-wide miR-155 binding map reveals widespread noncanonical microRNA targeting.
Specimen part
View SamplesThis SuperSeries is composed of the SubSeries listed below.
Evidence for compensatory upregulation of expressed X-linked genes in mammals, Caenorhabditis elegans and Drosophila melanogaster.
Sex, Specimen part, Cell line, Treatment
View SamplesExpression levels of human genes vary extensive among individuals. Gene expression determines cell function and characteristics thus this variation likely contributes to phenotypic variation. Genetic studies have shown that there is a heritable component to gene expression variation, and have identified genomic regions that contain polymorphic regulators. However, most of these regions are quite large, and few regulators have been identified. In this genetic of gene expression study, we used a large sample to search the genome for polymorphic regulators that influence gene expression, and followed up the results with deep sequencing of transcriptomes and molecular analyses. Key word(s): Transcriptome Analysis Overall design: genetics of gene expression study, 41 Coriell cell line samples examined.
Evidence for compensatory upregulation of expressed X-linked genes in mammals, Caenorhabditis elegans and Drosophila melanogaster.
No sample metadata fields
View SamplesBoth transcription and post-transcriptional processes, such as alternative splicing, play crucial roles in controlling developmental programs in metazoans. Recently emerged RNA-seq method has brought our understanding of eukaryotic transcriptomes to a new level, because it can resolve both gene expression level and alternative splicing events simultaneously. To gain a better understanding of cellular differentiation in gonads, we analyzed mRNA profiles from Drosophila testes and ovaries using RNA-seq. We identified a set of genes that have sex-specific isoforms in wild-type (WT) gonads, including several transcription factors. We found that differentiation of sperms from undifferentiated germ cells induced a dramatic downregulation of RNA splicing factors. Our data confirmed that RNA splicing events are significantly more frequent in the undifferentiated cell-enriched bag of marbles (bam) mutant testis, but downregulated upon differentiation in WT testis. Consistent with this, we showed that genes required for meiosis and terminal differentiation in WT testis were mainly regulated at the transcriptional level, but not by alternative splicing. Unexpectedly, we observed an increase in expression of all families of chromatin remodeling factors and histone modifying enzymes in the undifferentiated cell-enriched bam testis. More interestingly, chromatin regulators and histone modifying enzymes with opposite enzymatic activities are coenriched in undifferentiated cells in testis, suggesting that these cells may possess dynamic chromatin architecture. Finally, our data revealed many new features of the Drosophila gonadal transcriptomes, and will lead to a more comprehensive understanding of how differential gene expression and splicing regulate gametogenesis in Drosophila. Our data provided a foundation for the systematic study of gene expression and alternative splicing in many interesting areas of germ cell biology in Drosophila, such as the molecular basis for sexual dimorphism and the regulation of the proliferation vs terminal differentiation programs in germline stem cell lineages. Overall design: RNA-Seq experiments for four Drosophila melanogaster samples: (1) bam mutant testes, (2) wild-type testes, (3) bam mutant ovaries, (4) wild-type ovaries
Evidence for compensatory upregulation of expressed X-linked genes in mammals, Caenorhabditis elegans and Drosophila melanogaster.
Specimen part, Subject
View SamplesThe aim of this research is to uncover the molecular mechanisms of how Regnase-1 degrades cytokine mRNAs. Inflammation is mediated by proinflammatory cytokines and cytokine expression is tightly regulated in innate immune cells such as macrophages and dendritic cells controlling their activation and maturation. Cytokine mRNA expression is controlled at both transcriptional and post-transcriptional levels, and post-transcriptional damping of cytokine expression is a critical step for resolution of inflammation and prevention of unintended tissue damage. However, the mechanisms of RNA metabolism in immune system is not clear. Thus, the aim of this research project is to investigate the molecular mechanisms of RNA metabolism by Regnase-1 in immune system.
Translation-dependent unwinding of stem-loops by UPF1 licenses Regnase-1 to degrade inflammatory mRNAs.
Cell line
View SamplesThe anti-HIV humoral immune response following acute infection is delayed and ineffective. HIV envelope protein gp120 binds to and signals through 47 on T cells. We show that gp120 also binds and signals through 47 on B cells, resulting in an abortive proliferative response. In primary B cells, gp120 signaling through 47 resulted in increased expression of TGF-1 and the B cell inhibitory receptor FcRL4. Co-culture of B cells with HIV-infected autologous CD4+ T cells also resulted in increased B cell FcRL4 expression. These findings indicate that, in addition to inducing chronic immune activation, viral proteins can contribute directly to HIV-associated B cell dysfunction, thus providing a mechanism whereby the virus subverts the early HIV-specific humoral immune response.
The HIV-1 envelope protein gp120 impairs B cell proliferation by inducing TGF-β1 production and FcRL4 expression.
Specimen part, Disease, Time
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