Project description:Forming tight interaction with both Purkinje and granule cells (GCs), Bergmann glia (BG) are essential for cerebellar morphogenesis and neuronal homeostasis. However, how BG act in this process is unclear without comprehensively transcriptomic landscape of BG. Here, high temporal-resolution investigation of transcriptomes with FACS-sorted BG revealed the dynamic of genes within given functions and pathways enabled BG to assist neural migration and construct neuron-glia network. We found the peak time of GCs migration (P7-10) was strikingly coincided with the downregulation of extracellular matrix (ECM) related genes by prevailing transcriptional repression, and the disrupting of which by Setdb1 ablation at P7-10 in BG led to the significant migration defect of GCs by abnormal ECM expression emphasizing the criticality of Nfix-Setdb1 mediated H3K9me3 repressive complex for the precise regulation of GCs migration in vivo. Thus, BG’s transcriptomic landscapes offer an insight into the mechanism by which BG are in-depth integrated in cerebellar neural network.
Project description:We have evidence to believe that the BG-1 cells (named as BG-1 NIEHS here) we had obtained some years ago and provided to some laboratories are actually a clonal variation of MCF-7 cells. This only became evident from a recent Short Tandem Repeats (STR) analysis. We also have obtained another source of BG-1 cells from an investigator in France which we have named BG-1 FR. In this study, we compared gene expression profile in the two BG-1 lines (BG-1 FR or BG-1 NIEHS) and MCF-7 cells to identify differential genes set. We then will compare within each cell line and determine gene expression changes in response to E2 treatment that are specific for mechanism of ER’s actions in each cell type.
Project description:We have recently discovered that deletion of Ptpn11, which codes for protein tyrosine phosphatase Shp2, blocks Bergmann glia (BG) formation and cerebellar foliation, whereas expressing a constitutively active Mek1 (Map2k1), Mek1DD, reverses the Ptpn11-deficient phenotypes, uncovering a previously unappreciated role of BG in folding of the cerebellar cortex. Relatively little is known regarding to the BG induction. The goal of the study was to determine molecular features of newly generated BG. To identify transcripts enriched in nascent BG, we performed RNA-seq of microdissected cerebellar tissues from wild type (WT), En1cre/+;Ptpn11F/F (Ptpn11-cKO), and En1cre/+;Ptpn11F/F;R26Mek1DD/+ (Ptpn11-cKO;MEK) embryos at E12.5, E13.5, and E14.5. As BG are initially formed at E13.5, we reasoned that BG-enriched transcripts should be increased from E12.5 to E14.5, decreased in Ptpn11-cKO cerebella, and restored in Ptpn11-cKO;MEK cerebella. By intersecting differentially expressed (DE) genes based on the above-mentioned assumptions, we wanted to identify genes that are specifically expressed in BG and affected by Ptpn11 deletion. Conclusions: though RNA-seq and subsequent validation, we have successfully identified genes that enriched in nascent BG in the developing mouse cerebellum.
Project description:In vertebrates, non-lens bg-crystallins are widely expressed in various tissues, but their functions are unknown. The molecular mechanisms of trefoil factors, initiators of mucosal healing and being greatly involved in tumorigenesis, have remained elusive.A naturally existing 72-kDa complex of non-lens bg-crystallin (a-subunit) and trefoil factor (b-subunit), named bg-CAT, was identified from frog Bombina maxima skin secretions. Its a-subunit and b-subunit (containing three trefoil factor domains), with a non-covalently linked form of ab2, show significant sequence homology to ep37 proteins, a group of non-lens bg-crystallins identified in newt Cynops pyrrhogaster and mammalian trefoil factors, respectively. The bg-CAT showed multiple cellular effects on human umbilical vein endothelial cells. Low dosages of bg-CAT (25-50 pM) were able to stimulate cell migration and wound healing. At high concentrations, it induced cell detachment (EC50 10 nM) and apoptosis. The bg-CAT was rapidly endocytosed via intracellular vacuole formation. Under confocal microscope, some of the vacuoles were translocated to nucleus and partially fused with nuclear membrane. However, what exactly target of bg-CAT act on HUVECs nuclear is still unknown. Primary cultured HUVECs treated with bg-CAT (25 nM, 2 h) were selected for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain the genome wide level of significant differential gene expression induced by bg-CAT on HUVECs in order to get clues about bg-CAT action mechanisms. These findings illustrate novel cellular functions of non-lens bg-cyrstallins and action mechanism via association with trefoil factors, serving as clues for investigating the possible occurrence of similar molecules and action mechanisms in mammals.
Project description:Forming tight interaction with both Purkinje and granule cells (GCs), Bergmann glia (BG) are essential for cerebellar morphogenesis and neuronal homeostasis. However, how BG act in this process is unclear without comprehensively transcriptomic landscape of BG. Here, high temporal-resolution investigation of transcriptomes with FACS-sorted BG revealed the dynamic of genes within given functions and pathways enabled BG to assist neural migration and construct neuron-glia network. We found the peak time of GCs migration (P7-10) was strikingly coincided with the downregulation of extracellular matrix (ECM) related genes by prevailing transcriptional repression, and the disrupting of which by Setdb1 ablation at P7-10 in BG led to the significant migration defect of GCs by abnormal ECM expression emphasizing the criticality of Nfix-Setdb1 mediated H3K9me3 repressive complex for the precise regulation of GCs migration in vivo. Thus, BG’s transcriptomic landscapes offer an insight into the mechanism by which BG are in-depth integrated in cerebellar neural network.
Project description:Molecular mechanisms of anti-cancer activities of BG-P1600-TAT were explored employing genome-wide expression profiling experiments. Human neuroblastoma cell line SK-N-FI and primary cells SKNAS were treated with 30µM of the BG-P1600-TAT for 48 hours, harvested, and total RNA was immediately isolated from three biological replicates of control (vehicle-treated) and BG-P1600-TAT-treated cells. Gene expression profiling experiments identified 14-gene BG-P1600-TAT molecular interference signature captured most biologically important significantly enriched records reflecting the putative molecular mechanisms of anti-cancer activities of the BG-P1600-TAT. In BG-P1600-TAT treated SK-N-FI cells, 753 differentially expressed genes (DEGs) were identified compared to control vehicle-treated cells. Among 753 DEGs, 427 genes were down-regulated and 326 genes were up-regulated. In SKNAS cells, BG-P1600-TAT showed a significant effects on signal transduction pathways activated during cellular responses to IL-1alpha, TNF-alpha, EGF, TGF, PDGF, and AR. Further BG-P1600-TAT also showed a significant effect on multiprotein complexes of potential biological and therapeutic significance, including several complexes engaged during apoptosis (BCL-2 family protein complex; Survivin complex; BAX complex; Caspase complex), angiogenesis (VEGF-A complex; Thrombospondin complex), and cell adhesion (Galectin complex; Integrin alpha/beta complexes).
Project description:Since few years, yeast cell wall components and especially beta-glucans (BG) have been identified as potential stimulators of the innate immune system in murine and human species. A large screening of crude and BG-enriched components from Saccharomyces cerevisiae has been performed on murine macrophages. A priming effect with bacterial ligands was revealed in terms of pro-inflammatory cytokines release. To further characterize the responsiveness of bone marrow derived-macrophages which express high levels of dectin-1, the major receptor of BG, transcriptional analysis would provide more hypotheses about the genes and signaling pathways triggered by yeast cell wall compounds in macrophages. Gene expression profiling was performed in murine BMDM pretreated with a set of three BG-containing cell wall compounds and then stimulated with LPS. Conditions with BG-enriched pretreatment clustered together in contrast to the crude compound and mock pretreatment conditions that remained separated whatever the time point analyzed, with a greater number of differentially-expressed genes following the crude compound treatment compared to BG-enriched pretreatment. BG-enriched pretreatment induced a specific set of genes in mouse macrophages, involving the PI3K/AKT signaling pathway. Among them, the two main upregulated genes by BG-enriched priming condition were considered for further analysis and their associated-protein production were consistently increased in BMDM pretreated with BG-enriched compound. Microarray results were confirmed using RT-qPCR on a different set of samples.
Project description:In vertebrates, non-lens bg-crystallins are widely expressed in various tissues, but their functions are unknown. The molecular mechanisms of trefoil factors, initiators of mucosal healing and being greatly involved in tumorigenesis, have remained elusive.A naturally existing 72-kDa complex of non-lens bg-crystallin (a-subunit) and trefoil factor (b-subunit), named bg-CAT, was identified from frog Bombina maxima skin secretions. Its a-subunit and b-subunit (containing three trefoil factor domains), with a non-covalently linked form of ab2, show significant sequence homology to ep37 proteins, a group of non-lens bg-crystallins identified in newt Cynops pyrrhogaster and mammalian trefoil factors, respectively. The bg-CAT showed multiple cellular effects on human umbilical vein endothelial cells. Low dosages of bg-CAT (25-50 pM) were able to stimulate cell migration and wound healing. At high concentrations, it induced cell detachment (EC50 10 nM) and apoptosis. The bg-CAT was rapidly endocytosed via intracellular vacuole formation. Under confocal microscope, some of the vacuoles were translocated to nucleus and partially fused with nuclear membraneï®. However, what exactly target of bg-CAT act on HUVECs nuclear is still unknown. Primary cultured HUVECs treated with bg-CAT (25 nM, 2 h) were selected for RNA extraction and hybridization on Affymetrix microarrays. We sought to obtain the genome wide level of significant differential gene expression induced by bg-CAT on HUVECs in order to get clues about bg-CAT action mechanisms. These findings illustrate novel cellular functions of non-lens bg-cyrstallins and action mechanism via association with trefoil factors, serving as clues for investigating the possible occurrence of similar molecules and action mechanisms in mammals. Experiment Overall Design: We used microarrays to analysis genome wide level of significant differential gene expression induced by bg-CAT on HUVECs.Four independent biological replicates of HUVECs treated with bg-CAT (25 nM, 2 h) were compared with normal control by SAM. The significant differential expression of 123 genes (fold changeâ¥3, q value =0, FDR (false discovery rate)=0). 121 genes were up-regulated, among which members of nuclear receptor subfamily 4 (NR4A) were the most prominent. Only 2 genes were down-regulated (including collagen type I) (Supporting information Fig. S1 and Table S1 in accompanying publication). Members of NR4A exhibit differential roles in determining cell growth or cell death depending on its location in the nucleus or mitochondria. NR4A1 (also called Nur77, TR3) mediates cell apoptosis through translocation from nucleus to mitochondria and induction of cytochrome c releasing . Significant activation of NR4A members suggests these orphan nuclear receptors may be involved in the mediation of bg-CAT biological functions, like proapoptotic action of the protein at high concentrations. Up-regulated expression of a number of matrix metalloproteinases by bg-CAT could facilitate cell migration and detachment. The bg-CAT also induced the expression of a number of cytokines, including interleukin 1, interleukin 8 and interleukin 6, as well as various chemokines in HUVECs. These data provide clues for study in detail of molecular pathways through which bg-CAT exerts its biological functions.
Project description:To explore molecular mechanisms of anti-cancer activities of BG-P400-TAT, genome-wide expression profiling experiments were carried out . Human neuroblastoma SKNAS cells were treated with 30µM of the BG-P400-TAT for 48 hours, harvested, and immediately processed for RNA isolation from three biological replicates of control and drug-treated cells. BG-P400-TAT targets among intracellular multiprotein complexes NF-kB complex, Survivin complex, Bcl-2 complex, and VEGF-A complex and integrated with signal transduction pathways of EGF, FGF1, AR, estradiol, TNF, and IL-1