The chromatin of individual chromosomes is organized into chromosome territories (CTs) in the interphase nucleus. The spatial arrangement of CTs is non-random and evolutionarily conserved. The gene-dense and gene-poor CTs are positioned in the nuclear center and periphery, respectively. As candidates for key molecules involved in nuclear organization, we have investigated the nuclear actin-related proteins (Arps), which include the evolutionarily conserved actin-family together with conventional actin. We used a conditional knockout system with chicken DT40 cells to analyze the functions of the actin-related protein Arp6. Consistent with a previous identification of Arp6 in the SRCAP chromatin remodeling complex, the histone variant H2AZ was significantly decreased in the chromatin of Arp6-deficient cells. Most importantly, Arp6-deficient cells had impaired radial positioning of both gene-poor macrochromosome and gene-rich microchromosome CTs. A transcription microarray analysis of the cells suggests that the radial positioning of CTs impacts only a limited number of genes and plays an active role in repression, rather than in induction. As far as we know, this report is the first observation that an inner nuclear protein is required for the radial distribution of CTs, and will provide new insight into the mechanisms and physical significance of the positioning of CTs in the nucleus.
The actin family member Arp6 and the histone variant H2A.Z are required for spatial positioning of chromatin in chicken cell nuclei.
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View SamplesThe histone variant H2A.Z is evolutionarily conserved from yeast to vertebrates. H2A.Z regulates gene expression when localized to promoter region. Recently, we identified two genes encoding H2A.Z, H2A.Z-1 and H2A.Z-2 in vertebrate genome. However, it is not clear that both H2A.Z-1 and H2A.Z-2 were required for the function of H2A.Z in gene regulation. To address this issue, we generated the H2A.Z-1 and H2A.Z-2 double knock out (KO) cells in chicken DT40 cells. The expression pattern of H2A.Z-1 and H2A.Z-2 double KO cells was compared with WT cells to characterize the genes regulated by H2A.Z-1 and H2A.Z-2.
The actin family member Arp6 and the histone variant H2A.Z are required for spatial positioning of chromatin in chicken cell nuclei.
Specimen part, Cell line
View SamplesA specific set of genes involved in regulating cellular immune response, antigen presentation, and T cell activation and survival were down-regulated 7 days after LVAD placement. 6 months following LVAD placement, the expression levels of these genes were significantly increased; yet importantly, remained significantly lower than age and sex-matched samples from healthy controls. Overall design: Examination of the effect of LVAD implant on peripheral blood transcriptome. Blood was drawn before LVAD placement, 7 days post implant, and 180 days post implant. RNA sequencing was performaed on all samples.
Identification of differentially expressed transcripts and pathways in blood one week and six months following implant of left ventricular assist devices.
Specimen part, Subject, Time
View SamplesWe analyzed a role of histone deacetylases in alternative splicing regulation. Using human exon arrays we identified a list of 683 genes whose splicing changes after HDAC inhibition with sodium butyrate.
Histone deacetylase activity modulates alternative splicing.
Cell line
View SamplesWe analyzed a role of Brd2 protein in transcription and alternative splicing. 289 genes change alternative splicing after Brd2 knockdown and 1459 genes alter gene expression compared to cells treated with negative control siRNA.
The C-terminal domain of Brd2 is important for chromatin interaction and regulation of transcription and alternative splicing.
Cell line
View SamplesHuman Peptidoglycan Recognition Proteins (PGRPs) kill bacteria, likely by over-activating stress responses in bacteria. To gain insight into the mechanism of PGRP killing of Escherichia coli and bacterial defense against PGRP killing, gene expression in E. coli treated with a control protein (bovine serum albumin, BSA), human recombinant PGRP (PGLYRP4), gentamicin (aminoglycoside antibiotic), and CCCP (membrane potential decoupler) were compared. Each treatment induced unique and somewhat overlapping pattern of gene expression. PGRP highly increased expression of genes for oxidative and disulfide stress, detoxification and efflux of Cu, As, and Zn, repair of damaged proteins and DNA, methionine and histidine synthesis, energy generation, and Fe-S clusters repair. PGRP also caused marked decrease in the expression of genes for Fe uptake and motility.
Peptidoglycan recognition proteins kill bacteria by inducing oxidative, thiol, and metal stress.
Specimen part
View SamplesGroup 2 innate lymphoid cells (ILC2) are tissue-resident innate lymphocytes that are derived from common lymphoid progenitor (CLP). While specific progenitors and transcription factors essential for ILC2 differentiation have been well studied, external factors that regulate the commitment from CLP to ILC lineage, site that promote ILC2 terminal differentiation, and stromal cells that provide optimal microenvironment for ILC2 specific development are not fully understood. we demonstrated that the three key external factors such as concentration of IL-7 and the strength and duration of Notch signaling conditionally determined the fate of CLP toward T cell, B cell, or ILC lineages, which seems to be an important process from CLP to CHILP differentiation in the fetal liver. Furthermore, we identified ILC progenitors lacking the developmental potential to become T or B cells, and KLRG1- immature ILC2 that require STAT5 for functional maturation in the mesentery. We also identified PDGFRa+gp38+ mesenchymal cells in the mesentery that support ILC2 differentiation from ILC progenitors but not from CLP. Finally, single-cell RNA-sequencing (scRNA-seq) analysis of mesenteric cells demonstrated that PDGFRa+gp38+ cells are heterogeneous populations. Collectively, our result suggested that early differentiation of ILC2 occurs in the primary lymphoid organ with regulation of environmental factors, and final differentiation occurs in the peripheral tissues once after CHILP migrate into the periphery. Overall design: Duplicate samples (mouse 1 and mouse 2) were processed for single cell-based RNA sequencing with Illumina HiSeq 2500 with 50 paired-end reads, using barcorded RNA library.
Peripheral PDGFRα<sup>+</sup>gp38<sup>+</sup> mesenchymal cells support the differentiation of fetal liver-derived ILC2.
Sex, Cell line, Subject
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