Gene microarray of human embryonic stem cells, differentiated at three development stages, to investigate changes in the genomic transcripts associated with their glycome.
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ABSTRACT: We are interested in investigating changes in both the glycome and transcriptome of human embryonic stem cells upon differentiation. We have chosen as a model system to differentiate human ES cells into neural spheres using a published protocol by Zhang, S.C. et al. (2001; Nat Biotech. 19: 1129-33). Based on the information provided by microarray analysis, proteins of interest can be further investigated to associate a particular glycosyltransferase, for example, with production of a specific glycan structure at a particular stage. Techniques such as the use of RNAi for the knock-down or transfection of hESCs to effect the overexpression of the transcript, followed by subsequent analysis of the glycan structures can be employed. Three developmental stages will be investigated: Stage 1: undifferentiated stem cells; Stage 2: differentiation into embryoid bodies; Stage 3: differentiation into neural spheres. In addition to characterizing the cell surface for glycomic “fingerprints” we want to characterize the genomic transcripts associated with the glycome.
Project description:We are interested in investigating changes in both the glycome and transcriptome of human embryonic stem cells upon differentiation. We have chosen as a model system to differentiate human ES cells into neural spheres using a published protocol by Zhang, S.C. et al. (2001; Nat Biotech. 19: 1129-33). Based on the information provided by microarray analysis, proteins of interest can be further investigated to associate a particular glycosyltransferase, for example, with production of a specific glycan structure at a particular stage. Techniques such as the use of RNAi for the knock-down or transfection of hESCs to effect the overexpression of the transcript, followed by subsequent analysis of the glycan structures can be employed.
Project description:The reprogramming of human fibroblasts to generate induced pluripotent stem cells (hiPSCs) has been achieved through the expression of only a few exotic factors1-8, which is morphologically and molecularly verified in outer cellular states by characteristic markers, due to the remodeling of the somatic cell transcription programs in inner cellular states to the ES-like condition. Transcription factor-induced reprogramming to self-renewal and pluripotency raises the question as to how the exotic factors act to bring about these changes in the two cellular states9-11. Here, we applied RNA profiling to uncover gene expression changes and glycan profiling12 to survey structural changes in glycans, to compare hiPSCs and parental somatic cells, in total 51 cells, which were originally cultured and established, and the changes were analyzed by the combination of standard statistical techniques and a network approach13. We fist found a gene expression signature of 2502 genes with significant difference between iPSCs and SCs, and by the following network analysis by considering the expression signature, we found a network signature of 28 regulatory networks of 76 genes, which were related to the glycan biosynthetic pathways including 3 glycosyltransferase, in addition to well known signal pathways and cell-cell interaction pathways. Concomitantly, we found a glycan signature of six glycan structures characterized 16 lectins on lectin microarray by the correspondence with 12 glycosyltransferases in expression signature. In particular, the correspondence detected between the three expression signatures revealed 14 candidate glycosyltransferase, which are responsible for glycan transfer related to known epitopes for the differentiation such as SSEA epitope family in glycan biosynthesis pathway, based on characteristic changes in the cellular surface states of the hiPSCs. This sheds new light on a possible linkage between the inner and outer cellular states for reprogramming to self-renewal and pluripotency in hiPSC. Gene expressions in human induced pluripotent stem (iPS) cells and the provenance somatic cells . iPS cells were induced from four different somatic cells by infection of the retroviral vectors pMXs encoding OCT3/4, SOX2, KLF4 and c-MYC, simultaneously.
Project description:The reprogramming of human fibroblasts to generate induced pluripotent stem cells (hiPSCs) has been achieved through the expression of only a few exotic factors1-8, which is morphologically and molecularly verified in outer cellular states by characteristic markers, due to the remodeling of the somatic cell transcription programs in inner cellular states to the ES-like condition. Transcription factor-induced reprogramming to self-renewal and pluripotency raises the question as to how the exotic factors act to bring about these changes in the two cellular states9-11. Here, we applied RNA profiling to uncover gene expression changes and glycan profiling12 to survey structural changes in glycans, to compare hiPSCs and parental somatic cells, in total 51 cells, which were originally cultured and established, and the changes were analyzed by the combination of standard statistical techniques and a network approach13. We fist found a gene expression signature of 2502 genes with significant difference between iPSCs and SCs, and by the following network analysis by considering the expression signature, we found a network signature of 28 regulatory networks of 76 genes, which were related to the glycan biosynthetic pathways including 3 glycosyltransferase, in addition to well known signal pathways and cell-cell interaction pathways. Concomitantly, we found a glycan signature of six glycan structures characterized 16 lectins on lectin microarray by the correspondence with 12 glycosyltransferases in expression signature. In particular, the correspondence detected between the three expression signatures revealed 14 candidate glycosyltransferase, which are responsible for glycan transfer related to known epitopes for the differentiation such as SSEA epitope family in glycan biosynthesis pathway, based on characteristic changes in the cellular surface states of the hiPSCs. This sheds new light on a possible linkage between the inner and outer cellular states for reprogramming to self-renewal and pluripotency in hiPSC.
Project description:To explore the events during the differentiation process and timelines of various cells developed in cardiac organoid differentiation,we collected cell spheres for bulk RNA sequencing at each stage of differentiation (days 0, 1, 2, 3, 4, 6, and 30)
Project description:The UT-A1 urea transporter is crucial to the kidney’s ability to generate concentrated urine. Native UT-A1 from kidney inner medulla (IM) is a heavily glycosylated protein with two glycosylation forms of 97 and 117 kDa. In diabetes, UT-A1 protein abundance, particularly the 117 kD isoform, is significantly increased corresponding to an increased urea permeability in perfused IM collecting ducts, which plays an important role in preventing the osmotic diuresis caused by glucosuria. In this study, using sugar-specific binding lectins, we found that the carbohydrate structure of UT-A1 is also changed under diabetic conditions with increased amounts of sialic acid, fucose, and increased glycan branching. These changes were accompanied by altered UT-A1 association with the galectin proteins, α-galactoside glycan binding proteins. To explore the molecular basis of the alterations of glycan structures, the highly sensitive next generation sequencing (NGS) technology, Illumina RNA-seq, was employed to analyze genes involved in the process of UT-A1 glycosylation using streptozotocin (STZ) - induced diabetic rat kidney as the tissue source. Differential expression analysis combining quantitative PCR revealed that a number of important glycosylation related genes were changed under diabetic conditions. These genes include the glycosyltransferase genes Mgat4a, the sialylation enzymes St3gal1 and St3gal4and glycan binding protein galectin-3, -5, -8 and -9. In contrast, although highly expressed in kidney IM, the glycosyltransferase genes Mgat1, Mgat2, and fucosyltransferase Fut8, did not show any changes. We conclude that the alteration of these glycosylation related genes may contribute to changing the UT-A1 glycan structure, and therefore modulate kidney urea transport activity under diabetic conditions.
Project description:Dr. Stanley's laboratory is interested in 1) understanding the biological roles of specific classes of N-glycan in development and immunity through studies of glycosyltransferase mutant mice, 2) identifying complex binding specificities of galectins using a panel of CHO glycosylation mutants, and 3) determining how O-fucose glycans function in Notch receptor signaling and in modulating the interaction of Notch receptors with their ligands.
Project description:A genomic expression comparison was done among neural progenitor cells cultured on 2D substrates, 3D porous polystyrene scaffolds, and as 3D neural spheres (in vivo surrogate), with the goal of assessing the feasibility of establishing the meaning of 3D and associated physiological relevance at the molecular level Neural progenitor cells were cultured on 2D surfaces, in 3D scaffolds and as 3D neural spheres. Chemical cues are controlled by coating. Only spacial properties of the culture systems were compared.
Project description:We cultured adherent primary cell lines from NB tumor samples. Adherent primary cell lines from NB tumor samples have a subpopulation of neural crest progenitors that grow as spheres when cultured in low-binding conditions. We tested the changes in gene expression induced by endothelin-1 (ET1), a cytokine that regulates proliferation, migration, differentiation and survival of NC cells .
Project description:alpha-dystroglycan is a component of the dystrophin associated glycoprotein complex that binds components of the extracellular matrix (including laminin, perlecan and neurexin) via its carbohydrate groups. Recently, a group of muscular dystrophies have been identified due to the aberrant glycosylation of this molecule (dystroglycanopathies). The overexpression of the glycosyltransferase LARGE in several cell lines results in alpha-dystroglycan hyperglycosylation and enhanced ligand binding. The glycan structures induced by LARGE overexpression are unknown.
Project description:There is increasing evidence for tissue stem cells as potential source for cancers. However, the cellular and molecular mechanisms at the origin of this transformation remain elusive. Here we show that Delta-like1 (Dll1) mutation induces the oncogenic transformation of neural stem cell–derived neurospheres into oncogenic spheres capable of generating histological and molecular human glioblastoma (GBM)-like tumors upon subcutaneous and intracranial transplantations into nude mice. Serial transplantation assays suggest that Dll1 spheres tumorigenicity results from the oncogenic transformation of normal neural stem cell into GBM-producing stem cell. Compared differentiation of Dll1 vs. WT spheres shows the presence in Dll1 spheres of a subpopulation of cells which although fated to a glial lineage fail to differentiate terminally, in keeping with the astrocytic promoting function of Delta-Notch. This population of astrocyte progenitors proliferates actively and fails to down-regulate EGFR phosphorylation. These studies suggest that Dll1-induced tumorigenesis is restricted to the astrocytic lineage thereby providing a model for human GBM as well as an explanation for the duality of Notch signaling acting either as an oncogene or a tumor suppressor in stem/progenitor cells derived tumors, depending on the lineage commitment. Comparison between control (WT) and mutants (Dll1-3 and Dll1-5) cells was performed. Two biological replicates (n=3 each replicate) were used, and each replicate (n=3, total RNA pooled) was dye-swaped.