Circadian liver_wt and Clock mutants
One hundred ninety wildtype male C57BL/6J mice age 7-10 weeks were purchased from Jackson Laboratory and entrained to a 12:12 light:dark cycle for 2 weeks. Mice were placed in light-tight boxes on a 12:12 LD cycle for 4 weeks, then released into constant darkness. Starting 30 hours after entry into DD (CT18), tissues from 5 (skeletal muscle) or 10 (liver or SCN) wildtype mice were collected every 4 hours for 48 hours, for a total of 12 timepoints. At timepoints 34 through 58 hours in DD, tissues from age-matched male C57BL/6J Clock/Clock homozygous mutant mice that had been treated with the same light entrainment protocol as the wildtype were collected. Tissues were collected from 5 Clock/Clock mutants at each timepoint except for 34 and 46 hours after the onset of DD, when tissues from 10 Clock/Clock mice were collected and run as independent replicates. Mice were sacrificed by cervical dislocation, and the optic nerves were severed in complete darkness; brain dissection was performed using illumination from an infrared viewer (FJW Industries, Palatine, IL). SCNs were dissected out, pooled at a density of 5 per tube in 100 ?l RNAlater (Ambion, Austin, TX), frozen on dry ice, and stored at –80?C until use. Keywords: time course
Activation of the LMO2 oncogene through a somatically acquired neomorphic promoter in T-Cell Acute Lymphoblastic Leukemia
Somatic mutations within non-coding genomic regions that aberrantly activate oncogenes have remained poorly characterized. Here we describe recurrent activating intronic mutations of LMO2, a prominent oncogene in T-cell acute lymphoblastic leukaemia (T-ALL). Heterozygous mutations were identified in PF-382 and DU.528 T-ALL cell lines, in addition to 3.7% (6/160) of paediatric and 5.5% (9/163) of adult T-ALL patient samples. The majority of indels harbor de novo MYB, ETS1 or RUNX1 consensus binding sites. Analysis of 5’-capped RNA transcripts in mutant cell lines identified the usage of an intermediate promoter site, with consequential monoallelic LMO2 overexpression. CRISPR/Cas9-mediated disruption of the mutant allele in PF-382 cells markedly downregulated LMO2 expression, establishing clear causality between the mutation and oncogene dysregulation. Furthermore, the spectrum of CRISPR/Cas9-derived mutations provide important insights into the interconnected contributions of functional transcription factor binding. Finally, these mutations occur in the same intron as retroviral integration sites in gene therapy induced T-ALL, suggesting that such events occur at preferential sites in the non-coding genome.
RNA-seq profiles of Arabidopsis thaliana wild-type and trm4b-4
Methylation of carbon 5 in cytosine (5-methylcytosine; m5C) is a well-characterized DNA modification, and is also predominantly reported in highly abundant noncoding RNAs, such as rRNA and tRNA, in both prokaryotes and eukaryotes. However, the distribution and biological functions of m5C in plant mRNAs remain largely unknown. Here we develop an m5C RNA immunoprecipitation followed by deep sequencing approach (m5C-RIP-seq) to achieve transcriptome-wide profiling of RNA m5C in Arabidopsis thaliana. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and dot blot analyses reveal a dynamic pattern of m5C mRNA modification in various tissues and at different developmental stages. m5C-RIP-seq analysis identifies 6,045 putative m5C peaks in 4,465 expressed genes in young seedlings. m5C is enriched in coding sequences with two peaks located immediately after start codons and before stop codons, and is associated with mRNAs with low translation activity. We further show that a RNA (cytosine-5)-methyltransferase, tRNA specific methyltransferase 4B (TRM4B), exhibits the m5C mRNA methyltransferase activity. Mutations in TRM4B display defects in root development and decreased m5C levels in root mRNA. Furthermore, TRM4B affects transcript levels of the genes involved in root development, which is positively correlated with their mRNA stability and m5C levels. Our results suggest that m5C in mRNA is a new epitranscriptome marker widely distributed in plant genes, and that regulation of this modification is an integral part of gene regulatory networks underlying plant development.
RNA-seq analysis of differential gene expression in jejunal epithelial from Holstein Friesian bulls undergoing diet restriction and compensatory growth
The objective of this study was to examine the effect of dietary restriction and subsequent re-alimentation induced compensatory growth on the global gene expression profile of jejunum epithelial Holstein Friesian bulls (n=40) were assigned to one of two groups: restricted feed allowance (RES; n=20) for 125 days (Period 1) followed by ad libitum access to feed for 55 days (Period 2) or (ii) ad libitum access to feed throughout (ADLIB; n=20). All bulls received the same diet of 70% concentrate 30% grass silage through out the experimental trial,with the amount of feed provided different dependent on each treatment group. At the end ofeach period, 10 animals from each treatment group (RES, ADLIB) were slaughtered, and jejunum epithelial collected from all animals. RNA was extracted and jejununal epithelium gene expression was examined using RNAseq technology on all samles collected (end of Period 1: 10 samples each from ADLIB and RES groups; end of Period 2: 10 samples each from ADLIB and RES groups). Dietary restriction and subsequent re-alimentation were associated with altered expression of genes involved in digestion and metabolism, aswell as cellular protection and detoxification in jejunal epithelia. This information may be exploited in genomic breeding programmes to assist selection of cattle with a greater ability to compensate following a period dietary restriction.
Circadian rhythm in clock mutants
One hundred ninety wildtype male C57BL/6J mice age 7-10 weeks were purchased from Jackson Laboratory and entrained to a 12:12 light:dark cycle for 2 weeks. Mice were placed in light-tight boxes on a 12:12 LD cycle for 4 weeks, then released into constant darkness. Starting 30 hours after entry into DD (CT18), tissues from 5 (skeletal muscle) or 10 (liver or SCN) wildtype mice were collected every 4 hours for 48 hours, for a total of 12 timepoints. At timepoints 34 through 58 hours in DD, tissues from age-matched male C57BL/6J Clock/Clock homozygous mutant mice that had been treated with the same light entrainment protocol as the wildtype were collected. Tissues were collected from 5 Clock/Clock mutants at each timepoint except for 34 and 46 hours after the onset of DD, when tissues from 10 Clock/Clock mice were collected and run as independent replicates. Mice were sacrificed by cervical dislocation, and the optic nerves were severed in complete darkness; brain dissection was performed using illumination from an infrared viewer (FJW Industries, Palatine, IL). SCNs were dissected out, pooled at a density of 5 per tube in 100 ul RNAlater (Ambion, Austin, TX), frozen on dry ice, and stored at –80 degrees C until use. This SuperSeries is composed of the SubSeries listed below.
TaqMan Human miRNA array profile of Mycobacterium tuberculosis H37Rv infected THP-1 differentiated macrophages cells.
Differentially regulated miRNA candidates in H37Rv infected THP-1 cells were analysed with respect to uninfected THP-1 reference samples. THP-1 cells are monocytes differentiated to macrophages after treatment with PMA for 48 hrs. Total RNA was isolated from infected THP-1 cells after 24 hrs of infection, cDNA was synthesized for TLDA real time PCR reaction using TaqMan MicroRNA Reverse Transcription kit and Megaplex Human Pool A and Pool B stem loop RT primers (version 3.0) as per manufacturer’s protocol. Further real time reaction was performed on QuantStudio 12K Flex Real-Time PCR System (Applied Biosystems) by using cDNA (without pre-amplification) on TLDA card A and card B (version 3.0).
NUPR1 a new target in liver cancer: implication in controlling cell growth, migration, invasion and sorafenib resistance
Sorafenib, an oral multikinase inhibitor, is the only approved agent for the treatment of advanced hepatocellular carcinoma (HCC). However, its benefits is modest, also because its mechanism of action remains elusive, therefore, a better understanding of its molecular action and molecular targets are needed. On the basis of our previous studies, here, we investigated the role of the nuclear protein 1 (NUPR1) in HCC and its role in the context of sorafenib treatment. NUPR1 is a stress-inducible protein over-expressed in different malignancies, however, its role in HCC is not yet fully understood. We found that NUPR1, is over-expressed in 53% of primary human HCC samples. Knockdown of NUPR1 significantly increased cell sensitivity to sorafenib and inhibits cell growth, migration and invasion of HCC cells in vitro and tumorigenicity in vivo. Moreover, NUPR1 silencing influenced expression of target genes RelB and IER3. Unsurprisingly, RelB and IER3 knockdown also inhibited HCC cells viability, growth and migration. By gene expression profiling of HCC cells following stable NUPR1 knockdown, we found that genes functionally involved in cell death and survival, cellular response to therapies, lipid metabolism, cell growth and proliferation, molecular transport and cellular movement were mostly suppressed. Network analysis of dynamic gene expression identified NF-κB and ERK as down-regulated gene nodes, and several genes known to be involved in hepatocarcinogenesis were also suppressed. In addition, we identified Runt-related transcription factor 2 (RUNX2) gene as a NUPR1 down-regulated gene. We also demonstrated that RUNX2 gene silencing inhibited HCC cells viability, growth, migration and increased cell sensitivity to sorafenib. Conclusion: We propose that NUPR1/RELB/IER3/RUNX2 pathway play pivotal role in hepatocarcinogenesis. The identification of NUPR1/RELB/IER3/RUNX2 pathway as a potential therapeutic target may contribute to the development of new treatment strategies for HCC management.
Heart Chamber Evolution Reveals Roles of Gene/Genome Duplications on Continuous Character Evolution in Vertebrates
We sequenced at mRNA level in adult hearts of zebrafish, pamprey and sea squirt. Combined with other 11 vertebrate heart RNA-Seq data online, we conducted comprehensive evolutionary genomic analyses to address the contribution of gene/genome duplications on heart structure evolution. We observed that number of duplicate genes expressed in heart increased gradually with the increase of heart chamber number along the vertebrate phylogeny, despite that most of them were duplicated at the time near to the origin of vertebrates or more ancient. Our research provides a clear-cut example to show the relationship among gene duplication, continuous character evolution like heart structure evolution and nature selection.
Genome-wide identification of glucocorticoid receptor binding sites in the whole hippocampus of adrenalectomised male rats given corticosterone infusion and stressed or non-stressed.
We have applied next-generation sequencing technology to obtain high through-put profiling of glucocorticoid receptor (GR) DNA binding in whole hippocampus from male rat brain. By obtaining sequence from immunoprecipitated, sonicated chromatin, we have generated genome-wide binding maps for GR in two contexts, testing whether chromatin is primed for GR binding according to the animal's acute experience. In one context (stressed) adrenalectomised rats are infused with corticosterone while undergoing restraint stress. In the second context (non-stressed control) rats are infused with the same corticosterone profile but restraint stress is omitted. We find that GR binding was highly similar suggesting factors other than GR binding may account for any context-dependent alterations in GR function associated with acute stress. We show that GR is positioned near to genes associated with structural and functional organisation of the hippocampus at largely intergenic and intronic sites. Glucocorticoid response element sequences support a majority of GR binding in this tissue but may be reinforced by NF-1 and/or basic-helix loop helix transcription factors binding their nearby recognition motifs. We found little evidence for tethering of GR to other factors, or for the usage of negative glucocorticoid response elements.
Identification of novel lung genes in bronchial epithelium by serial analysis of gene expression
A description of the transcriptome of human bronchial epithelium should provide a basis for studying lung diseases including cancer. We demonstrate here that minute epithelial specimens obtained by bronchial brushings afford reliable profiling by serial analysis of gene expression (SAGE) leading to lung gene discovery. We have deduced global gene expression profiles of bronchial epithelium and lung parenchyma, based upon a vast data set of nearly two million sequence tags from 21 SAGE libraries generated from individuals with a history of smoking. Cluster and linear regression analysis demonstrate the repeatability and reproducibility of bronchial SAGE libraries, and suggest that the transcriptome of the bronchial epithelium is distinct from that of lung parenchyma and other tissue types. This distinction is highlighted by the abundant expression of signature genes that reflect tissue-specific and region-specific functions. Through our analysis we have identified novel bronchial-enriched genes and a novel transcript variant for surfactant, pulmonary-associated protein B in lung parenchyma. Conspicuously, gene expression associated with ciliogenesis is evident in bronchial epithelium. Additionally, it is noted that a large number of unmapped tags awaits further investigation. This study represents a comprehensive delineation of the bronchial and parenchyma transcriptomes, identifying more than 20,000 known and hypothetical genes expressed in the human lung, constituting one of the largest human SAGE studies reported to date. This SuperSeries is composed of the SubSeries listed below.
Drosophila HNF4 promotes glucose-stimulated insulin secretion and increased mitochondrial function in adults [RNA-seq]
Although mutations in the nuclear receptor HNF4A were identified as the cause of Maturity Onset Diabetes of the Young 1 (MODY1) nearly two decades ago, the mechanisms by which HNF4A regulates glucose homeostasis remain unclear. Here we report that loss of Drosophila HNF4 recapitulates hallmark symptoms of MODY1, including adult-onset hyperglycemia, glucose intolerance and impaired glucose-stimulated insulin secretion (GSIS). These defects are linked to an unexpected role for dHNF4 within mitochondria to directly regulate mtDNA transcription, while also promoting the expression of nuclear genes involved in oxidative phosphorylation (OXPHOS) and Hex-C, a homolog of the MODY2 gene Glucokinase. dHNF4 is required in the fat body and insulin-producing cells to maintain glucose homeostasis by supporting a developmental switch toward OXPHOS and GSIS at the transition to adulthood. These findings establish an animal model for MODY1 and define a developmental reprogramming of metabolism to support the energetic needs of the mature animal.
E3 SUMO ligase PIAS3 fine-tunes dorsoventral patterning and visual response of cones in the mouse retina but is not essential for photoreceptor cell fate specification
Differentiation of distinct neurons in the developing retina is controlled by combinatorial action of a small subset of transcription factors and signalling molecules. Protein inhibitor of activated STAT3 (PIAS3) has been implicated in guiding the specification of both rod and cone photoreceptors through posttranslational modification of key retinal transcription factors. To investigate its role during retinal development, we deleted exon 2-5 of the mouse Pias3 gene, which resulted in complete loss of the PIAS3 protein. Pias3-/- mice did not exhibit any overt phenotype, and retinal lamination appeared normal by histology even at 18 months. We detected reduced photopic b-wave amplitude by electroretinography (ERG) analysis following green light stimulation of Pias3-/- retina at postnatal day (P) 21, suggesting a compromised visual response of medium wavelength (M) cones. No change was evident in response of short wavelength (S) cones or rod photoreceptors until 7 months. Immunohistochemistry demonstrated altered distribution of cone photoreceptors as revealed by increased S-opsin expression in the M-cone dominant dorsal retina. Transcriptome profiling of P21 and 18-month old Pias3-/- retina revealed aberrant expression of genes associated with photoreceptor function. Our studies suggest redundancy in SUMOylation-associated transcriptional control mechanisms and identify a specific though limited role of PIAS3 in modulating spatial patterning and optimal function of cone photoreceptor subtypes in the mouse retina.
Canonical and non-canonical regulatory roles of androgen receptor variant 7 in prostate cancer
The androgen receptor splice variant 7 (AR-V7) lacks the ligand-binding domain; is detected with increased frequency in advanced prostate cancer and is postulated to be one crucial mechanism for disease progression and therapeutic resistance to androgen deprivation in castration–resistant prostate cancer (CRPC). Targeting AR-V7 or unique downstream targets could provide novel therapeutic approaches for CRPC. Here, we report that, independent of ligand, AR-V7 binds not only to the androgen-responsive element (ARE) sites inducing canonical AR signaling but also to non-canonical target sites where ligand-stimulated full-length AR (AR-FL) does not bind. These AR-V7 “solo” binding sites are mainly found at gene promoters and are co-occupied by a zinc-finger transcription factor ZFX and the co-activator BRD4, both of which physically interact with AR-V7. Consequently, AR-V7 not only recapitulates AR-FL action without androgen but uniquely regulates transcripts correlating with AR-V7 expression in the TCGA prostate cancer cohort. Mechanistically, ZFX appears to function as a pioneer factor for AR-V7 at solo-binding sites and BRD4 inhibitors but not anti-androgens suppress AR-V7 action at solo-binding sites as well as AR-V7-dependent growth. Additionally, knockdown of ZFX, or two downstream targets uniquely co-activated by AR-V7 (ZNF32 and FZD6), also suppressed growth of AR-V7-dependent CRPC cells. AR-V7 directly activated genes differentiate tumor from normal prostate tissues and predict poor prognosis in patients. Thus AR-V7 has both canonical and non-canonical regulatory functions in CRPC, which may provide new therapeutic avenues.
Chromosome-wide mapping of interactions of yeast nucleoporin Nup2 on chromosome VI.
This series is a complementary data set for the manuscript entitled "Nup-PI: The Nucleopore-Promoter Interactions of Genes in Yeast." (Mol. Cell, 2006). Experimental Background: Genomic interaction sites of nuclear proteins were mapped by the in vivo ChEC technique described in Schmid et al. (2004) Mol. Cell 16, 147-157. Genome-wide probes that are suitable for hybridization of microarrays were prepared. In brief, MboI restriction fragments that were internally cleaved by the MN moiety of the fusion proteins were amplified and labelled. The procedure is explained in detail in the manuscript. "Nup-PI: The Nucleopore-Promoter Interactions of Genes in Yeast." (Schmid et al., Mol. Cell 2006). Experiments: Genome-wide probes were prepared from control, uncleaved chromatin, as well as chromatin cleaved by H2b-MN and Nup2-MN. All samples were from raffinose grown cells induced for 1 hour by galactose in logarithmic growth phase. Keywords: Genome-wide ChEC analysis, Mapping of Nuclear Pore Proteins
overexpression/knockdown MEG3 in C2C12 cell lines
MEG3 was known as a growth suppressor in tumor cells by activating p53. Besides, MEG3 could regulate transforming growth factor-β (TGF-β) signaling pathway, which is the key regulator of skeletal myogenesis and can enhance the proliferation of myogenic cells. Previous study also showed MEG3 was highly expressed in the paraxial mesoderm and probably regulated muscle development. To investigate the potential function of MEG3 in muscle development, we detected the expression levels of protein-coding genes after MEG3 over-expression or knockdown in C2C12 cell line using microarrays.
Gene Expression Profile Signatures Indicate a Role for Wnt Signaling in Endothelial Commtment From Embryonic Stem Cells
Embryonic stem (ES) cells have the potential to generate a variety of cell lineages including endothelial cells, blood cells and smooth muscle cells. flk1-expressing cells derived from ES cells serve as vascular progenitors. We have used global gene expression analysis in order to establish a comprehensive list of candidate genes in the developing vasculature during ES cell differentiation in vitro. A large set of genes, including growth factors, cell surface molecules, transcriptional factors, and members of several signal transduction pathways that are known to be involved in vasculogenesis or angiogenesis, were found to have expression patterns as expected. Some unknown or functionally uncharacterized genes were differentially regulated in flk1+ cells compared with flk1­ cells, suggesting possible roles for these genes in vascular commitment. Particularly, multiple components of the Wnt signaling pathway were differentially regulated in flk1+ cells, including Wnt proteins, their receptors, downstream transcriptional factors, and other components belonging to this pathway. Activation of the Wnt signal was able to expand vascular progenitor populations whereas suppression of Wnt activity reduced flk1+ populations. Suppression of Wnt signaling also inhibited the formation of matured vascular capillary-like structures during late stages of EB differentiation. These data indicate a requisite and ongoing role for Wnt activity during vascular development, and the gene expression profiles identify candidate components of this pathway that participate in vascular cell differentiation. Keywords: Time course, development, endothelial cell, angiogenesis, embryonic stem cells, mouse, vasculature, Wnt signaling
High-protein intake eliminates the weight loss-induced improvement in insulin sensitivity
The purpose of this study was to conduct a randomized-controlled trial to evaluate the effect of a high-protein (HP) diet weight loss (WL) on changes in body composition, insulin sensitivity and skeletal muscle gene expression profile in postmenopausal women who were obese and randomized to one of three dietary intervention groups: 1) a weight maitenance group, 2) a weight loss group (normal protein intake, 0.8 g protein/kg body weight per day) and 3) a weight loss group (high protein intake, 1.2 g protein/kg body weight per day) and studies before and after they lost 10% of their body weight (WL groups) or a time-matched weight maintenacne period.
Interactions between Saccharomyces cerevisiae WW domains and proteins discovered using protein microarrays
A total of 12 WW domains from Saccharomyces cerevisiae were expressed and purified as fusion proteins to either GST or MBP. The fusion proteins were chemically biotinylated and applied to duplicate protein microarrays. Data processing revealed a total of 587 interactions between the domains and 207 proteins. Most of these interactions have not been previously observed. Keywords: Protein microarray analysis of yeast WW domains
Trajectories of DNA hydroxymethylation across human brain development
Epigenetic processes play a key role in orchestrating transcriptional regulation during the development of the human central nervous system. We previously described dynamic changes in DNA methylation occurring during human fetal brain development, but other epigenetic processes operating during this period have not been extensively explored. Of particular interest is DNA hydroxymethylation (5hmC), a modification that is enriched in the human brain and hypothesized to play an important role in neuronal function, learning and memory. In this study, we quantify DNA hydroxymethylation across the genome of 71 human fetal brain samples spanning 23 to 184 days post-conception.
The Functional Genomic Landscape of Human Breast Cancer Drivers, Vulnerabilities, and Resistance (RNASeq)
Large-scale genomic studies have identified multiple somatic aberrations in breast cancer, including copy number alterations, translocations, and point mutations. Still, identifying causal variants and emergent vulnerabilities that arise as a consequence of genetic alterations remain major challenges. We performed whole genome shRNA “dropout screens” on 77 breast cancer cell lines. Using a new hierarchical linear regression algorithm to score our screen results and integrate them with accompanying detailed genetic and proteomic information, we identify novel vulnerabilities in breast cancer, including new candidate “drivers,” and reveal general functional genomic properties of cancer cells. Comparisons of gene essentiality with drug sensitivity data suggest potential resistance mechanisms, novel effects of existing anti-cancer drugs, and new opportunities for combination therapy. Finally, we demonstrate the utility of this large dataset by identifying BRD4 as a potential target in luminal breast cancer, and PIK3CA mutations as a resistance determinant for BET-inhibitors. Additional formatted data can be found at http://neellab.github.io/bfg/. Code and tutorials for the siMEM algorithm can be found at http://neellab.github.io/simem/.
Effects of Estrogen and Tamoxifen on Ishikawa cells after 24h and 48h
Treatment with the breast cancer drug tamoxifen confers a risk of developing uterine tumors or other endometrial pathologies. Tamoxifen is a selective estrogen receptor modulator, which demonstrates tissue-specific activity although the mechanisms remain poorly understood. Both estradiol and tamoxifen act as estrogen agonists on the human uterus, and therefore have the potential to promote carcinogenicity. Estradiol and tamoxifen elicit cellular responses via the estrogen receptors (ER), which are involved in multiple signalling pathways. The effects at the molecular level are further influenced by the differential recruitment of co-factors and the presence of specific promoter motifs in target genes. In this study, ER positive (+) Ishikawa cells are used as a model to investigate the overall effect of treatment with either 17b-estradiol or 4-hydroxytamoxifen on the gene expression profiles. Keywords: Comparison of estradiol and tamoxifen on Ishikawa human uterine cells after 24h or 48h
Expression Profiling of Spalax ehrenbergi: bioprospecting for hypoxia tolerance
This study compares response to hypoxia in muscle between 2 hypoxia tolerant species of Spalax ehrenbergi, blind subterranean mole rat . The blind subterranean mole rat (Spalax ehrenbergi superspecies) is an excellent model of hypoxic tolerance, living underground and exposed to fluctuating O2 and CO2 levels. Unique structural and functional adaptations of the cardiovascular and respiratory systems allow survival at severely reduced oxygen tension. In this study we have compared expression profiles of muscle tissue between two hypoxia tolerant species of Spalax ehrengergi at normoxic (21%) and hypoxic (3%) levels of oxygen concentration by cross species hybridization using a mouse cDNA array containing 15,000 gene elements. Results uncover numerous genes involved in angiogenesis, apoptosis, and oxidative stress and responding in a species specific manner to hypoxia. Among the most striking, cardiac ankyrin repeat protein (Carp) and activating transcription factor 3 (Atf3), LIM and cysteine-rich domains 1 (Lmcd1) and syndecan 2 (Sdc2). These results support the hypothesis that Spalax is variably adapted to fluctuating oxygen tension. Differences may involve very specific metabolic pathways and functional adaptations at the structural and molecular levels. Elucidation of the natural variation and evolutionary changes under hypoxia within this superspecies may have biomedical applications in ischemic syndromes and cancer. Keywords: hypoxia, Spalax, cDNA microarray
Modulation of Indoleamine 2, 3-dioxygenase 1 Expression by Activated Human T cells in Breast Cancer Cells is Controlled by DNA Promoter Methylation
Tumor infiltrating lymphocytes (TILs) play a critical role in modulating the immunoediting features in certain malignancies like triple negative breast cancer (TNBC). Nevertheless, much is still unknown concerning the specific responses of tumors when challenged by lymphocyte infiltration. Based on this void, we conducted a immuno-phenotype comparison using mRNA sequencing between the TNBC cell line MDA-MB-231 and the luminal breast cancer cell line MCF7 after both were co-cultured with activated human T-cells. We found that, though the cytokine-induced immune signature of the two cell lines was similar, MDA-MD-231 cells were able to transcribe IDO1 at a significantly higher level than MCF7 cells. Though no differences occurred in upstream JAK/STAT1 signaling or IDO1 mRNA stability between the two cell lines, stimulation with IFNγ was able to differentially induce IDO protein expression and enzymatic activity in ER- cell lines compared to ER+ cell lines. Further experiments show that 5-aza-deoxycytidine treatment was able to reverse suppression of IDO1 expression in MCF7 cells, suggesting DNA methylation as a potential determinant in IDO1 induction. By analyzing TCGA breast cancer datasets, we discovered subtype-specific mRNA and promoter methylation differences in IDO1, with TNBC/basal subtypes exhibiting lower methylation/higher expression and ER+/luminal subtypes exhibiting higher methylation/lower expression. We confirmed this trend of IDO1 methylation by bisulfite pyrosequencing breast cancer cell lines and an independent cohort of primary breast tumors. Taken together, these findings suggest that IDO1 methylation regulates anti-immune responses in breast cancer subtypes and could be used as a predictive biomarker for IDO inhibitor-based immunotherapy.
ASH1L links histone H3 lysine 36 di-methylation to leukemia
The histone methyltransferases MLL and ASH1L are trithorax-group proteins that interact genetically through undefined molecular mechanisms to regulate developmental and hematopoietic gene expression. Here we show that the lysine 36-dimethyl mark of histone H3 (H3K36me2) written by ASH1L is preferentially bound in vivo by LEDGF, an MLL-associated protein that co-localizes with MLL, ASH1L and H3K36me2 on chromatin genome wide. Furthermore, ASH1L facilitates recruitment of LEDGF and wild type MLL proteins to chromatin at key leukemia target genes, and is a crucial regulator of MLL-dependent transcription and leukemic transformation. Conversely KDM2A, an H3K36me2 demethylase and Polycomb-group silencing protein, antagonizes MLL-associated leukemogenesis. Our studies illuminate the molecular mechanisms underlying epigenetic interactions wherein placement, interpretation and removal of H3K36me2 contribute to the regulation of gene expression and MLL leukemia, and suggest ASH1L as a target for therapeutic intervention.
MicroRNA expression analysis of livers of F1 male offspring fathered from control mice or stressed mice
Psychological stress is highly prevalent in modern society. Both epidemiologic and experimental animal studies demonstrate that chronic psychological stress exerts adverse effects on the initiation and/or progression of many diseases. Here, using a mouse model of restraint stress, we report the discovery of a novel signaling pathway linking paternal stress exposure to the reprogram of hepatic gluconeogenesis in the offspring. Offspring fathered by stressed males (Stress-F1) exhibits hyperglycemia as a result of enhanced hepatic gluconeogenesis, conpared to offspring from control fathers (Control-F1). Mechanistically, protein levels of PEPCK, a key gluconeogenic enzyme, were significantly increased, while its mRNA levels were unaffected in the stress-F1 mice, pointing to a posttranscriptional regulatory mechanism. Because MicroRNAs often play an important role in regulating gene expression at the posttranscriptional level, we investigated the expression profile of MicroRNAs in livers from Control-F1 and Stress-F1 mice.
Tissue-Specific Transcriptomics Reveals Role of the Unfolded Protein Response in Maintaining Fertility upon Heat Stress in Arabidopsis
Elevated temperature occurring at reproductive stage has great impact on gametophyte development and therefore ultimate fruit or seed set in plants, the underlying molecular mechanisms are less understood. We investigated the effect of elevated temperature stress on reproductive development in Arabidopsis with tissue-specific transcriptome profiling and observed distinct response patterns between vegetative and reproductive tissues. Heat stress exposure affected reproductive developmental programs including early phases of anther/ovule development and meiosis process, and genes participating in the unfolded protein response (UPR) were enriched among the heat up-regulated reproductive tissue-specific genes. We found that the bzip28bzip60 double mutant defective in UPR were sensitive to elevated temperature stress in terms of reduced silique length and fertility comparing to the wild-type plants. Comparison of heat responsiveness between the wild-type and bzip28zip60 plants identified 521 genes that were regulated by bZIP28 and bZIP60 upon heat stress at reproductive stage, most of which were non-canonical UPR genes. Further ChIP-Seq data revealed 133 direct targets of bZIP28 in Arabidopsis seedlings subjected to heat stress, of which 39 target genes were up-regulated by heat stress at reproductive stage. Our results provide novel insights into heat responsiveness in reproductive tissues and demonstrate the protective roles of UPR for maintaining fertility upon heat stress in plants.
YY1 plays an essential role at all stages of B cell differentiation [ChIP-seq]
YY1 is a ubiquitously expressed transcription factor that has been demonstrated to be essential for pro-B cell development. However, the role of YY1 in other B cell populations has never been investigated. It has been proposed that YY1 is a key regulator for the germinal center B cell program since the YY1 motif was present in much higher frequency in germinal center B cell signature genes than signature genes of other B cell subsets. Indeed, in accord with this prediction, we demonstrated that deletion of YY1 by Cg1-Cre completely prevented differentiation of naïve B cells into germinal center B cells and plasma cells after antigen stimulation. To determine if YY1 was also required for the differentiation of other B cell populations, we deleted YY1 with CD19-Cre and found that all peripheral B cell subsets including B1 B cells require YY1 for their differentiation. By deleting YY1 acutely with ER-Cre, we demonstrated that all B cell subsets require YY1 for their maintenance. ChIP-seq shows that YY1 predominantly binds to promoters, and pathway analysis of the genes which bind YY1 show that they are enriched in ribosomal functions, mitochondrial functions such as bioenergetics, and functions related to transcription, such as mRNA splicing, metabolism of RNA. By RNA-seq analysis of differentially expressed genes, we demonstrated that YY1 normally activates genes involved in mitochondrial bioenergetics, while it normally downregulates genes involved in transcription, mRNA splicing, NF-kB signaling pathways, AP-1 transcription factor network, chromatin remodeling, cytokine signaling pathways, cell adhesion, cell proliferation and c-Myc targets.
Gene-expression profile in a series of non-Hodgkin lymphoma (NHL) patients
PIM serine/threonine kinases are overexpressed, translocated or amplified in multiple B-cell lymphoma types. We have explored the frequency and relevance of PIM expression in different B-cell lymphoma types, and investigated whether PIM inhibition could be a rational therapeutic approach. Increased expression of PIM2 was detected in subsets of mantle cell lymphoma (MCL), diffuse large B-cell lymphoma (DLBLC), follicular lymphoma (FL), marginal zone lymphoma-MALT type (MZL-MALT), chronic lymphocytic leukemia (CLL) and nodal marginal zone lymphoma (NMZL) cases. Increased PIM2 protein expression was associated with an aggressive clinical course in ABC-DLBCL patients. Pharmacological and genetic inhibition of PIM2 revealed p4E-BP1(Thr37/46) and p4E-BP1(Ser65) as molecular biomarkers characteristic of PIM2 activity, and indicated the involvement of PIM2 kinase in regulating mTORC1. The simultaneous genetic inhibition of all three PIM kinases induced changes in apoptosis and cell cycle. In conclusion, we show that PIM2 kinase inhibition is a rational approach in DLBCL treatment, identify appropriate biomarkers for pharmacodynamic studies, and provide a new marker for patient stratification.
Pulmonary metastasis in xenograft model after orthotopic implantation
Metastasis is a major factor for mortality in patients with hepatocellular carcinoma (HCC). Thus, there is a need for predictive biomarker(s) for detecting the tipping point before metastasis, so as to prevent further deterioration. To discover early warning signals of pulmonary metastasis in HCC, we analysed time-series gene expression data in the spontaneous pulmonary metastasis mouse HCCLM3-RFP model with our novel dynamic network biomarker (DNB) method. To simulate tumour growth and metastasis in patient livers, we used the spontaneous pulmonary metastasis mouse model, HCCLM3-RFP, which involves the orthotopic transplanted human HCCLM3 cell line labelled with a stable fluorescent protein.We observed that, hepatic tumours in orthotopic xenograft HCCLM3-RFP mice grew gradually from the second to the fifth week after orthotopic implantation in the primary liver tissue, whereas spontaneous pulmonary metastasis occurredonly at the last time point (the fifth week after orthotopic implantation).Thus, we chose the second, third, fourth, and fifth weeks after orthotopic implantation as observation points to collect liver tumours of five orthotopic xenograft mice at each time point and to assess the whole-genome expression.
Gene Expression Analysis of Neural Stem Cells
Tissue from the telencephalon was isolated from E13.5 BALB/C mouse and allowed to culture as neurospheres in the presence of FGF2. These cultures were assessed for undifferentiated neural stem cells by the expression of Nestin and were found to be ~98% Nestin positive. Comparisons of these nestin positive neural stem cells will be made to R1 ES cells to identify the genes that are important in totipotent, self-renewing ES cells vs. commitment to the multipotent, self-renewing neural stem cell phenotype. Keywords: other
YY1 plays an essential role at all stages of B cell differentiation [RNA-seq]
YY1 is a ubiquitously expressed transcription factor that has been demonstrated to be essential for pro-B cell development. However, the role of YY1 in other B cell populations has never been investigated. It has been proposed that YY1 is a key regulator for the germinal center B cell program since the YY1 motif was present in much higher frequency in germinal center B cell signature genes than signature genes of other B cell subsets. Indeed, in accord with this prediction, we demonstrated that deletion of YY1 by Cg1-Cre completely prevented differentiation of naïve B cells into germinal center B cells and plasma cells after antigen stimulation. To determine if YY1 was also required for the differentiation of other B cell populations, we deleted YY1 with CD19-Cre and found that all peripheral B cell subsets including B1 B cells require YY1 for their differentiation. By deleting YY1 acutely with ER-Cre, we demonstrated that all B cell subsets require YY1 for their maintenance. ChIP-seq shows that YY1 predominantly binds to promoters, and pathway analysis of the genes which bind YY1 show that they are enriched in ribosomal functions, mitochondrial functions such as bioenergetics, and functions related to transcription, such as mRNA splicing, metabolism of RNA. By RNA-seq analysis of differentially expressed genes, we demonstrated that YY1 normally activates genes involved in mitochondrial bioenergetics, while it normally downregulates genes involved in transcription, mRNA splicing, NF-kB signaling pathways, AP-1 transcription factor network, chromatin remodeling, cytokine signaling pathways, cell adhesion, cell proliferation and c-Myc targets.
Transcriptomic Analysis of Endothelial Cells from Fibrovascular Membranes in Proliferative Diabetic Retinopathy
Purpose: Identification of RUNX1 via next-generation sequencing (NGS) of fibrovascular membranes in patients with proliferative diabetic retinopathy. Methods: Transcriptomic analysis with Illumina HiSeq2000 of fibrovascular membrane and control retina CD31+ samples. The sequence reads were analyzed with ANOVA (ANOVA) and targets with significance (fold change > +/-1.5 and p-value < 0.05) were selected for with Cufflinks, DeSeq2, Partek E/M, and EdgeR. qRT–PCR validation was performed using SYBR Green assays along with Western blots, siRNA, and MUSE proliferation assays. Results: Using an optimized data analysis workflow, we mapped sequence reads per sample to the human genome (hg19) and identified genes that were statistically significant in all four statistical packages. P-values ranged from 8.78E-10 to 0.05. Using this gene list for ontology, highly significant annotation clusters included inflammatory, vascular development, and cell adhesion pathways. Conclusions: Our study represents the first detailed transcriptomic analysis of CD31+ cells from fibrovascular membrane and CD31+ cells from control retinas with biologic replicates, generated by RNA-seq technology. The preferential selection of inflammatory and angiogenic pathways using this gene list is highly consistent with DR pathogenesis, which involves leaky and aberrant vessel growth.
TERT  rearrangements are frequent in neuroblastoma and identify aggressive tumors
Whole genome sequencing detected structural rearrangements of TERT in 17/75 high stage neuroblastoma with 5 cases resulting from chromothripsis. Rearrangements were associated with increased TERT expression and targeted immediate up- and down-stream regions of TERT, placing in 7 cases a super-enhancer close to the breakpoints. TERT rearrangements (23%), ATRX deletions (11%) and MYCN amplifications (37%) identify three almost non-overlapping groups of high stage neuroblastoma, each associated with very poor prognosis
Profiling of 5-methylcytosine (m5C) methylation in Arabidopsis thaliana wild-type
Methylation of carbon 5 in cytosine (5-methylcytosine; m5C) is a well-characterized DNA modification, and is also predominantly reported in highly abundant noncoding RNAs, such as rRNA and tRNA, in both prokaryotes and eukaryotes. However, the distribution and biological functions of m5C in plant mRNAs remain largely unknown. Here we develop an m5C RNA immunoprecipitation followed by deep sequencing approach (m5C-RIP-seq) to achieve transcriptome-wide profiling of RNA m5C in Arabidopsis thaliana. Liquid chromatography coupled with tandem mass spectrometry (LC-MS/MS) and dot blot analyses reveal a dynamic pattern of m5C mRNA modification in various tissues and at different developmental stages. m5C-RIP-seq analysis identifies 6,045 putative m5C peaks in 4,465 expressed genes in young seedlings. m5C is enriched in coding sequences with two peaks located immediately after start codons and before stop codons, and is associated with mRNAs with low translation activity. We further show that a RNA (cytosine-5)-methyltransferase, tRNA specific methyltransferase 4B (TRM4B), exhibits the m5C mRNA methyltransferase activity. Mutations in TRM4B display defects in root development and decreased m5C levels in root mRNA. Furthermore, TRM4B affects transcript levels of the genes involved in root development, which is positively correlated with their mRNA stability and m5C levels. Our results suggest that m5C in mRNA is a new epitranscriptome marker widely distributed in plant genes, and that regulation of this modification is an integral part of gene regulatory networks underlying plant development.
Transcriptomics of human pleural mesothelial cell line Met-5A infected with Streptococcus pneumoniae
The objectives of the study were to examine the gene expression profile of human pleural mesothelial cells following infection with Streptococcus pneumoniae. The abstract is as follows: Streptococcus pneumoniae (Spn) is a major causative organism of empyema, an inflammatory condition occurring in the pleural sac. In this study, we used human and Spn cDNA microarrays to characterize the transcriptional responses occurring during initial contact between Spn and a human pleural mesothelial cell line (PMC) in vitro. Using stringent filtering criteria, 42 and 23 Spn genes were up-and down-regulated respectively. In particular, genes encoding factors potentially involved in metabolic processes and Spn adherence to eukaryotic cells were up-regulated e.g. glnQ, glnA, aliA, PsaB, LytB and nox. After Spn initial contact, 870 human genes were differentially regulated and the largest numbers of significant gene expression changes were found in canonical pathways for eukaryotic initiation factor 2 signaling (60 genes out of 171), oxidative phosphorylation (32/103), mitochondrial dysfunction (37/164), eIF4 and p70S6K signaling (28/142), mTOR signaling (27/182), NRF2-mediated oxidative stress response (20/177), epithelial adherens junction remodeling (11/66) and ubiquitination (22/254). The cellular response appeared to be directed towards host cell survival and defense. Spn did not activate NF-kB or phosphorylate p38 MAPK or induce cytokine production. Moreover, Spn infection of TNF-α pre-stimulated PMC inhibited production of IL-6 and IL-8 secretion by >50% (p<0.01). In summary, his descriptive study provides datasets and a platform for examining further the molecular mechanisms underlying the pathogenesis of empyema.
MCF7 breast cancer cell response to estradiol
The experiment was designed to uncover the response to estradiol (E2) in MCF7 breast cancer cells. The first step was to create a reference sample in a ligand free environment. For that, the cells were placed into estradiol free media for 3 days, which reduced the binding between ER-alpha and E2. The cells were then ready to be re-exposed to E2. Following the introduction of E2, the resultant changes were tracked by multiple ChIP-seq experiments. The experiments were performed at 0, 5, 10, 20, 40, 80, 160, 320, 640 and 1280 minutes after the stimulation. Each ChIP-seq experiment was carried out with a different antibody to measure genome-wide changes in genomic occupancy of their specific protein targets. Specifically, the studied protein factors and histone modifications were: ER-alpha, H3K4me3, and H2AZ. Other previously published data from the same set of experiments are available for Pol-II ChIP-Seq and RNA-Seq (GEO accession GSE62789 and GSE44800).
Global Gene Expression Profiles of Single-Cell Derived Fetal Rat Calvaria Cell Colonies with Adipocyte and Bone Markers
Single cell-derived colonies were obtained by sorting 21 days fetal Rat calvaria cells into microtitre wells using flow cytometry. Colonies were categorized according to a limited gene expression profiling for a specific bone (osteocalcin) and a specific adipocyte (adipsin) marker by real-time PCR. Colonies expressing neither, one or both bone and adipocyte markers are in the sample set. Microarray analysis will address the global gene expression profiles of CFU-O (bone marker only), CFU-F (neither bone nor adipocyte marker) and CFU-bipotential (both markers) derived from single cells. CFU-A (adipocyte marker only) samples are also available for analysis if warranted. Keywords: other
Autoantibody Epitope Spreading in the Pre-Clinical Phase Predicts Progression to Rheumatoid Arthritis [ANALYTE: Cytokine or chemokine]
Rheumatoid arthritis is a prototypical autoimmune arthritis affecting nearly 1% of the world population and is a significant cause of worldwide disability. Though prior studies have demonstrated the appearance of RA-related autoantibodies years before the onset of clinical RA, the pattern of immunologic events preceding the development of RA remains unclear. To characterize the evolution of the autoantibody response in the preclinical phase of RA, we used a novel multiplex autoantigen array to evaluate development of the anti-citrullinated protein antibodies (ACPA) and to determine if epitope spread correlates with rise in serum cytokines and imminent onset of clinical RA. To do so, we utilized a cohort of 81 patients with clinical RA for whom stored serum was available from 1-12 years prior to disease onset. We evaluated the accumulation of ACPA subtypes over time and correlated this accumulation with elevations in serum cytokines. We then used logistic regression to identify a profile of biomarkers which predicts the imminent onset of clinical RA (defined as within 2 years of testing). We observed a time-dependent expansion of ACPA specificity with the number of ACPA subtypes. At the earliest timepoints, we found autoantibodies targeting several innate immune ligands including citrullinated histones, fibrinogen, and biglycan, thus providing insights into the earliest autoantigen targets and potential mechanisms underlying the onset and development of autoimmunity in RA. Additionally, expansion of the ACPA response strongly predicted elevations in many inflammatory cytokines including TNF-α, IL-6, IL-12p70, and IFN-γ. Thus, we observe that the preclinical phase of RA is characterized by an accumulation of multiple autoantibody specificities reflecting the process of epitope spread. Epitope expansion is closely correlated with the appearance of preclinical inflammation, and we identify a biomarker profile including autoantibodies and cytokines which predicts the imminent onset of clinical arthritis.
Annotation and functional clustering of circRNA expression in rhesus macaque brain during aging
The abundance and function of circular RNAs (circRNAs) in mammalian brain have been reported, but their alterations in the biology of brain aging remain elusive. Here, using deep RNA profiling with linear RNA digestion by RNase R we explored a comprehensive map of changes in circRNA expression in rhesus macaque (macaca mulatta) brain in two age groups from adult (10 y) to aged (20 y) periods. Total 17,050 well expressed, stable circRNAs were identified. Cluster analysis reveals that dynamic changes in circRNA expression show the spatial-, sex- and age-biased specificities. On the basis of separate profiling of the RNAs, age-related circRNAs show differential correlation to host mRNA expression. Furthermore, two voltage-dependent L- and R-type calcium channel gene-derived circCACNA2D1 and circCACNA1E negatively regulate their host mRNA expression. Our results demonstrate the power of changes in circRNA expression to reveal insights into a potentially circRNA-mediated regulatory mechanism underlying the biology of brain aging.
The role of AR associated protein and lncRNA in androgen signaling
Prostate cancer is the most common cancer in men and AR downstream signalings promote prostate cancer cell proliferation. To investigate the AR signaling, we performed RNA sequence analysis in AR positive prostate cancer cell line, LNCaP. In addition, we used hormone-refractory prostate cancer model cells, Long term androgen deprivation (LTAD) to explore the differences of androgen signaling in prostate cancer progression. We analyzed the role of PSF, CTBP1-AS and COBLL1 which we identified as regulators of androgen signaling.
Circularized RNA sequencing of wild-type and Mrpp3 knock out mouse heart mitochondria
Here we find that circularization of RNA prior to deep sequencing enables the discovery and characterization of unprocessed mitochondrial RNAs. Using this approach we identify the most stable processing intermediates and the presence of intermediate processing products that are partially degraded and polyadenylated. Analysis of libraries constructed using RNA from mice lacking the nuclease subunit of the mitochondrial RNase P reveals the identities of stalled processing intermediates, their order of cleavage, and confirms the importance of RNase P (MRPP3) in generating mature mitochondrial RNAs. Using RNA circularization prior to library preparation should provide a generally useful approach to studying RNA processing in many different biological systems.
FM95-14 Fetal Myoblast Differentiation Time Series
Fetal myoblasts represent an important source of myogenic stem cells. Analysis of undifferentiated myoblasts and comparison to their cognate differentiated progeny will allow the ascertainment of genes that are important for maintaining myogenic stem cells. Fetal myoblasts (undifferentiated, time 0hr) will be compared to myoblasts cells allowed to differentiate by the removal of the SKBM-2 medium + growth factors and feeding with DMEM + 2.5% Horse serum. Time course : 0 hr, 6 hr, 12 hr, 18 hr, 24 hr, 36 hr, 48 hr, 3 days, 4 days, 7 days Keywords: other
Tamoxifen-associated endometrial tumors expose differential enhancer activity for Estrogen Receptor alpha [ChIP-Seq]
Tamoxifen, a small molecule inhibitor that binds the Estrogen Receptor alpha (ERα), blocks breast cancer progression while increasing the risk for endometrial cancer. In this study, we assessed genome-wide ERα-chromatin interactions in surgical specimens of endometrial tumors from patients who were previously treated for breast cancer with tamoxifen, and endometrial tumors from patients who were treated without tamoxifen. We compared ERα and signal at differential ERα sites in endometrial tumors of nine patients who received tamoxifen with endometrial tumors with six patients who never used tamoxifen. In addition, we performed H3K27ac (a marker for activity) ChIPs on the above mentioned endometrial tumors, and assed this signal at differential ERα sites. Compared to endometrial tumors of non-users, tamoxifen-associated endometrial tumors exposed higher H3K27ac intensities at ERα sites that are enriched in tamoxifen-associated endometrial tumors. Four tamoxifen-associated endometrial tumors that we used in our analysis have been previously published as Tumor A, B, D, and E in GSE81213.
SMYD5 regulates H4K20me3-marked heterochromatin to safeguard ES cell self-renewal and prevent spurious differentiation [ChIP-Seq]
Epigenetic regulation of chromatin states is thought to control the self-renewal and differentiation of embryonic stem (ES) cells. However, the roles of repressive histone modifications such as trimethylated histone lysine 20 (H4K20me3) in pluripotency and development are largely unknown. Here, we show that the histone lysine methyltransferase SMYD5 mediates H4K20me3 at heterochromatin regions. Depletion of SMYD5 leads to compromised self-renewal, including dysregulated expression of OCT4 targets, and perturbed differentiation. SMYD5 bound regions are enriched with repetitive DNA elements. Knockdown of SMYD5 results in a global decrease of H4K20me3 levels, a redistribution of heterochromatin constituents including H3K9me3/2, G9a, and HP1α, and de-repression of endogenous retroelements. A loss of SMYD5-dependent silencing of heterochromatin nearby genic regions leads to upregulated expression of lineage-specific genes, thus contributing to the decreased self-renewal and accelerated differentiation of SMYD5-depeleted ES cells. Altogether, these findings implicate a role for SMYD5 in regulating ES cell self-renewal and H4K20me3-marked heterochromatin.
Point mutations in exon 1B of APC reveal gastric adenocarcinoma and proximal polyposis of the stomach as a familial adenomatous polyposis variant
Gastric adenocarcinoma and proximal polyposis of the stomach is an autosomal dominant cancer predisposition syndrome of fundic gland polyposis with a significant risk of gastric adenocarcinoma. We mapped the gene to 5q22 and found loss of heterozygosity (LOH) only on 5q in fundic gland polyps from affected individuals. Sanger sequencing revealed novel point mutations in APC promoter 1B that co-segregated with disease. All three mutations reduced binding of YY1, and all three mutations showed abrogated activity of the APC promoter 1B luciferase assays. Whole genome sequencing of fundic gland polyps without 5q LOH identified somatic truncating mutations in APC.
H3.Y discriminates between HIRA and DAXX chaperone complexes and reveals unexpected insights into human DAXX-H3.3-H4 binding and deposition requirements
Histone chaperones prevent promiscuous histone interactions before chromatin assembly. They guarantee faithful deposition of canonical histones and functionally specialized histone variants into chromatin in a spatial- and temporally-restricted manner. Here, we identify the binding partners of the primate-specific and H3.3-related histone variant H3.Y using several quantitative mass spectrometry approaches, and biochemical and cell biological assays. We find the HIRA, but not the DAXX/ATRX, complex to specifically recognize H3.Y, explaining its presence in transcriptionally active euchromatic regions. Accordingly, H3.Y nucleosomes are enriched in the transcription-promoting FACT complex and depleted of repressive posttranslational histone modifications. H3.Y mutational gain-of-function analyses screens reveal an unexpected combinatorial amino acid sequence requirement for histone H3.3 interaction with DAXX but not HIRA, and for H3.3 recruitment to PML nuclear bodies. We demonstrate the importance and necessity of specific H3.3 core region and C-terminal amino acids in discriminating between distinct chaperone complexes. Further, ChIP-seq experiments reveal that in contrast to euchromatic HIRA-dependent deposition sites, human DAXX/ATRX-dependent regions of histone H3 variant incorporation are enriched in heterochromatic H3K9me3 and simple repeat sequences. These data demonstrate that H3.Y's unique amino acids allow a functional distinction between HIRA and DAXX binding and its consequent deposition into open chromatin.
Trichostatin A (TSA) inhibition of histone deacetylase in Arabiodopsis thaliana
Histone acetylation is involved in the regulation of gene expression in plants and eukaryotes. Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from histones, which is associated with the repression of gene expression. To study the role of histone acetylation in the regulation of gene expression during seed germination, trichostatin A (TSA), a specific inhibitor of histone deacetylase, was used to treat imbibing Arabidopsis thaliana seeds. GeneChip arrays were used to show that TSA induces up-regulation of 45 genes and down-regulation of 27 genes during seed germination. Eight TSA-up-regulated genes were selected for further analysis - RAB18, RD29B, ATEM1, HSP70 and four late embryogenesis abundant protein genes (LEA). A gene expression time course shows that these eight genes are expressed at high levels in the dry seed and repressed upon seed imbibition at an exponential rate. In the presence of TSA, the onset of repression of the eight genes is not affected but the final level of repressed expression is elevated. Chromatin immunoprecipitation and HDAC assays show that there is a transient histone deacetylation event during seed germination at one day after imbibition, which serves as a key developmental signal that affects the repression of the eight genes. Keywords: histone deacetylase inhibitor, developmental effects
Neuroblastoma cells undergo transcriptomic alterations during dissemination into the bone marrow and subsequent tumor progression
Background: Neuroblastoma is the most common extracranial solid tumor in childhood. The vast majority of stage M patients present with disseminated tumor cells (DTCs) in the bone marrow (BM). Although these cells represent a major obstacle in the treatment of neuroblastoma patients, their transcriptomic profile was not intensively analyzed so far. Results: RNA-Seq of stage M primary tumors, enriched BM-derived DTCs and the corresponding non-tumor mononuclear cells (MNCs) revealed that DTCs largely retained the gene expression signature of tumors. However, we identified 322 genes that were differentially expressed (q 2). Particularly genes encoded by mitochondrial DNA were highly up-regulated in DTCs, whereas e.g. genes involved in angiogenesis were down-regulated. Furthermore, 224 genes were highly expressed in DTCs and only slightly, if at all, in MNCs (q 6). Interestingly, we found that the gene expression profiles of diagnostic DTCs largely resembled those of relapse DTCs with only 113 differentially expressed genes under relaxed cut-offs (q 0.5). Notably, relapse DTCs showed a positional enrichment of 31 down-regulated genes encoded by chromosome 19, including five tumor suppressor genes (SIRT6, PUMA, STK11, CADM4 and GLTSCR2). Conclusion: This first RNA-Seq analysis of DTCs from neuroblastoma patients revealed their unique expression profile in comparison to the corresponding MNCs and tumor samples, and, interestingly, also expression differences between diagnostic and relapse DTCs preferentially affecting chromosome 19. As these alterations might be associated with treatment failure and disease relapse, they should be considered for further functional studies.
Seed germination in presence and absence of histone deaceatylase inhibitor, Trichostain A (TSA).
Histone acetylation is involved in the regulation of gene expression in plants and eukaryotes. Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from histones, which is associated with the repression of gene expression. To study the role of histone acetylation in the regulation of gene expression during seed germination, trichostatin A (TSA), a specific inhibitor of histone deacetylase, was used to treat imbibing Arabidopsis thaliana seeds. GeneChip arrays were used to show that TSA induces up-regulation of 45 genes and down-regulation of 27 genes during seed germination. Eight TSA-up-regulated genes were selected for further analysis - RAB18, RD29B, ATEM1, HSP70 and four late embryogenesis abundant protein genes (LEA). A gene expression time course shows that these eight genes are expressed at high levels in the dry seed and repressed upon seed imbibition at an exponential rate. In the presence of TSA, the onset of repression of the eight genes is not affected but the final level of repressed expression is elevated. Chromatin immunoprecipitation and HDAC assays show that there is a transient histone deacetylation event during seed germination at one day after imbibition, which serves as a key developmental signal that affects the repression of the eight genes. Keywords: histone deacetylase inbibition, developmental effects
Differential expression between mature zone of the olfactory organ and the dactyl of the walking legs, a taste organ
A cDNA microarray was constructed and used to assess mRNA abundance differences between two of the lobster’s major chemosensory structures, the mature zone of the olfactory organ and the dactyl of the walking legs, a taste organ. The 115 differences detected again emphasized the abundance of neurons in the olfactory organ, especially a cluster of mRNAs encoding cytoskeletal-associated proteins and cell adhesion molecules such as 14-3-3zeta, actins, tubulins, trophonin, Fax, Yel077cp, Suppressor of profilin 2, and gelsolin. Keywords: Differential expression
Adipose tissue from β-3 agonist-treated mice
We previously established the transcription factor Zfp423 is critical for maintaining white adipocyte identity through suppression of the thermogenic gene program. The loss of Zfp423 in mature adipocytes triggers the rapid conversion of energy-storing white adipocytes into thermogenic beige adipocytes in subcutaneous WAT. In contrast to subcutaneous WAT, visceral WAT is relatively resistant to browning. However, visceral adipocytes lacing Zfp423 are capable of inducing the thermogenic gene program upon β-3 adrenergic stimulus. Here, we generated mice lacking Zfp423 in visceral adipose by breeding transgenic mice expressing Cre recombinase under the control of the Wilms Tumor 1 locus (Wt1-Cre) to animals carrying the floxed Zfp423 alleles (Zfp423loxP/loxP) (“Vis-KO” mice). Inactivation of Zfp423 in visceral WAT gives rise to thermogenic adipocytes that share properties of subcutaneous beige adipocytes and classic brown adipocytes.
Determination of Lsd1 function in C2C12 myoblast cells by global transcriptome analysis
First, we aimed to identify genes whose transcript levels change at the onset of myogenic versus adipogenic differentiation of muscle precursors. We therefore compared RNA-seq results obtained from C2C12 cells differentiated for 1 day in myogenic and adipogenic medium. Out of these genes, we wanted to determine those whose expression was affected by altered Lsd1 levels. To this end, we performed RNA-seq in C2C12 cells upon LSD1 overexpression and Lsd1 knock-down in adipogenic medium and compared them to corresponding control cells.
TOP2 synergizes with BAF chromatin remodeling for resolution of facultative heterochromatin
Resolution and formation of facultative heterochromatin is essential to development, reprogramming, and oncogenesis. The mechanisms underlying these changes are poorly understood due to difficulty with interrogating heterochromatin dynamics and structure in vivo. BAF (mSWI/SNF) ATP-dependent chromatin remodeling complexes are known to promote chromatin accessibility. As the function of topoisomerase IIa (TOP2A) is largely dependent on BAF complexes in embryonic stem (ES) cells, we tested whether TOP2 was involved in BAF-mediated resolution of heterochromatin by performing ATAC-seq on ES cells treated with the TOP2 inhibitor ICRF-193, Brg1 (the primary ATPase subunit of esBAF complexes) conditional knockout cells, and Baf53a (a non-catalytic subunit dispensable for in vitro remodeling) conditional knockout cells. We found that TOP2 synergizes with BAF complexes genome-wide to resolve facultative heterochromatin to accessible chromatin at a large number of regulatory elements.
Circadian and feeding rhythms differentially affect rhythmic mRNA transcription and translation in mouse liver [RNASeq]
Diurnal oscillations of gene expression are a hallmark of rhythmic physiology across most living organisms. Such oscillations are controlled by the interplay between the circadian clock and feeding rhythms. While rhythmic mRNA accumulation has been extensively studied, comparatively less is known about their transcription and translation. Here, we quantified simultaneously temporal transcription, accumulation, and translation of mouse liver mRNAs under physiological light-dark conditions and ad libitum or night-restricted feeding in wild-type and Bmal1 deficient animals. We found that rhythmic transcription predominantly drives rhythmic mRNA accumulation and translation for a majority of genes. Comparison of wild-type and Bmal1 KO mice shows that circadian clock and feeding rhythms have broad impact on rhythmic genes expression, Bmal1 deletion having surprisingly more impact at the post-transcriptional level. Translation efficiency is differentially regulated during the diurnal cycle for genes with 5’-TOP sequences and for genes involved in mitochondrial activity and harboring a TISU motif. The increased translation efficiency of 5’-TOP and TISU genes is mainly driven by feeding rhythms but Bmal1 deletion impacts also amplitude and phase of translation, including TISU genes. Together this study emphasizes the complex interconnections between circadian and feeding rhythms at several steps ultimately determining rhythmic gene expression and translation.
esBAF chromatin remodeling complexes promote spacing of nucleosomes flanking pluripotency factor binding sites
We showed that topoisomerase II synergizes with BAF (mSWI/SNF) ATP-dependent chromatin remodeling complexes genome-wide to resolve facultative heterochromatin to accessible chromatin. To study the consequences of this on transcription factors, we performed MNase-seq on light digest of native chromatin in Brg1 conditional knockout embryonic stem (ES) cells. We found that spacing of nucleosomes flanking pluripotency factor binding sites specifically partially collapsed upon Brg1 deletion, indicating that pluripotency factor binding is likely lost.
Microglial repopulation rewires and rejuvenates the aged brain
Changes in microglial form and function contribute to age-related cognitive impairment. Developing methods to target microglia is critical to understand and prevent the adverse effects of aging. Using a specific colony-stimulating factor 1 receptor (CSF1R) inhibitor, our lab has shown that the majority of microglia can be eliminated from the CNS (Elmore et al., 2014). Withdrawal of the CSF1R inhibitor, stimulates brain-wide repopulation with new cells, that express microglial markers (Elmore et al., 2014; Elmore et al., 2015). The impact of these newly repopulated cells on the aged brain has not been explored, but will provide useful insight into the role of microglia in aging. In addition, the therapeutic potential of replacing “primed” or “senescent” microglia in the aged brain with new cells is of great interest. Therefore, our goal was to fully characterize the gene expression profiles of the aged control vs. aged repopulated brains in comparison to young controls.
Genome-wide Lsd1 chromatin occupancy in myoblast C2C12 cells by chromatin immunoprecipitation using an Lsd1 antibody followed by massive parallel sequencing
Purpose: The aim of this study is to identify the Lsd1 genome binding profile in myoblast C2C12 cells during myogenic and adipogenic differentiation. ChIP-seq libraries were prepared, sequenced using the standard Illumina protocol (HiSeq2000, single read, 50 bp v3), and mapped to the mouse mm10 reference genome by Bowtie. Data were further analyzed using the peak finding algorithm MACS 1.4.2. Homer software was used to annotate peaks, and all peaks with false discovery rate less than 1 % were included.
Small RNA sequencing of mock treated or Sindbis virus-infected wild type and RNaseIII knockout cells
To assess the impact of endogenous RNaseIII nucleases on the small RNA profile in the presence and absence of virus infection.
DNA damage signaling mediates the functional antagonism between replicative senescence and terminal muscle differentiation
The molecular determinants of muscle progenitor impairment to regenerate aged muscles are currently unclear. We show that in a mouse model of replicative senescence, decline in muscle satellite cell-mediated regeneration coincides with activation of DNA damage response (DDR) and impaired ability to differentiate into myotubes. Inhibition of DDR restored satellite cell differentiation ability. Moreover, in replicative human senescentfibroblasts DDR precluded MYOD-mediated activation of the myogenic program. A DDR-resistant MYOD mutant could overcome this barrier by resuming cell cycle progression. Likewise, DDR inhibition could also restore MYOD ability to activate the myogenic program in human senescent fibroblasts. Of note, we found that cell cycle progression is necessary for DDR-resistant MYOD mutant to reverse senescence-mediated inhibition of the myogenic program. These data provide the first evidence of DDR-mediated functional antagonism between senescence and MYOD-activated gene expression, and indicate a previously unrecognized requirement of cell cycle progression for the activation of the myogenic program.
Transcriptomics and methylomics of human monocytes [methylome]
The MESA Epigenomics and Transcriptomics Study has been launched to investigate potential gene expression regulatory methylation sites in humans by examining the association between CpG methylation and gene expression in purified human monocytes from a large study population (community-dwelling participants in the Multi-Ethnic Study of Atherosclerosis (MESA)). The MESA Epigenomics and Transcriptomics Study was funded by a National Heart, Lung and Blood Institute grant (R01HL101250) through the NIH Roadmap Epigenomics Program in 2009.
Differences of miRNA expression associated with ΔNp63β overexpressing OSCC cell line SQUU-B
Recent reports have revealed that EMT is involved in cancer invasion and progression including oral squamous cell carcinoma (OSCC). Previously, we have also studied on the association of p63 gene, a homolog of the p53 tumor suppressor gene, with EMT in OSCC cells. Furthermore, we also demonstrated that down-regulation of ΔNp63 accompanied with EMT and that re-expression of ΔNp63β by stable cDNA transfection in OSCC cell lines reverted the EMT phenotype. However, the detail mechanisms of ΔNp63β-mediated EMT remain to be unclear. Recent studies have shown that several microRNAs (miRNAs) are also involved in EMT process of human cancer by targeting EMT-related transcription factors. We thus sought to identify responsible miRNA associated with ΔNp63β-mediated EMT using miRNA microarray analyses.
Eomes related gene regulation in Definitive Endoderm (ChIP-seq)
Precisely co-ordinated activation of lineage specific transcription factors direct cell fate decisions during mouse early development. The T-box transcription factor Eomes is dynamically expressed during mouse gastrulation and is a key regulator of the anterior visceral endoderm (AVE), cardiac mesoderm and definitive endoderm (DE) lineages. The cis-acting regulatory elements that direct spatiotemporally restricted Eomes expression domains have yet to be elucidated. To understand transcriptional regulation of Eomes in Definitive Endoderm open chromatin data was generated by ATAC-seq and histone modifications identified by ChIP-seq. Interactions at the Eomes locus and the loci of two related transcription factors Foxa2 and Lhx1, was also determined by NG Capture-C.
Circadian and feeding rhythms differentially affect rhythmic mRNA transcription and translation in mouse liver [Ribosome Profiling]
Diurnal oscillations of gene expression are a hallmark of rhythmic physiology across most living organisms. Such oscillations are controlled by the interplay between the circadian clock and feeding rhythms. While rhythmic mRNA accumulation has been extensively studied, comparatively less is known about their transcription and translation. Here, we quantified simultaneously temporal transcription, accumulation, and translation of mouse liver mRNAs under physiological light-dark conditions and ad libitum or night-restricted feeding in wild-type and Bmal1 deficient animals. We found that rhythmic transcription predominantly drives rhythmic mRNA accumulation and translation for a majority of genes. Comparison of wild-type and Bmal1 KO mice shows that circadian clock and feeding rhythms have broad impact on rhythmic genes expression, Bmal1 deletion having surprisingly more impact at the post-transcriptional level. Translation efficiency is differentially regulated during the diurnal cycle for genes with 5’-TOP sequences and for genes involved in mitochondrial activity and harboring a TISU motif. The increased translation efficiency of 5’-TOP and TISU genes is mainly driven by feeding rhythms but Bmal1 deletion impacts also amplitude and phase of translation, including TISU genes. Together this study emphasizes the complex interconnections between circadian and feeding rhythms at several steps ultimately determining rhythmic gene expression and translation.
SET1A/COMPASS and shadow enhancers in the regulation of homeotic gene expression
The homeotic (Hox) genes are highly conserved in metazoans, where they are required for various processes in development and misregulation of their expression is associated with human cancer. In the developing embryo, Hox genes are sequentially activated in time and space according to their genomic position within Hox gene clusters. Accumulating evidence implicates both enhancer elements and non-coding RNAs in controlling this spatiotemporal expression of Hox genes, but disentangling their relative contributions is challenging. Here, we identify two cis-regulatory elements (E1 and E2) functioning as shadow enhancers to regulate the early expression of the HoxA genes. Simultaneous deletion of these shadow enhancers in embryonic stem cells leads to impaired activation of HoxA genes upon differentiation, while knockdown of a long non-coding RNA overlapping E1 has no detectable effect on their expression. Although MLL/COMPASS family of histone methyltransferases are known to activate transcription of Hox genes in other contexts, we find that individual inactivation of the MLL1-4/COMPASS family members has little effect on early Hox gene activation. Instead, we demonstrate that SET1A/COMPASS is required for full transcriptional activation of multiple Hox genes, but functions independently of the E1 and E2 cis-regulatory elements. Our results reveal multiple regulatory layers for Hox genes to fine-tune transcriptional programs essential for development.
Eomes related gene regulation in Definitive Endoderm (NG Capture-C)
Precisely co-ordinated activation of lineage specific transcription factors direct cell fate decisions during mouse early development. The T-box transcription factor Eomes is dynamically expressed during mouse gastrulation and is a key regulator of the anterior visceral endoderm (AVE), cardiac mesoderm and definitive endoderm (DE) lineages. The cis-acting regulatory elements that direct spatiotemporally restricted Eomes expression domains have yet to be elucidated. To understand transcriptional regulation of Eomes in Definitive Endoderm open chromatin data was generated by ATAC-seq and histone modifications identified by ChIP-seq. Interactions at the Eomes locus and the loci of two related transcription factors Foxa2 and Lhx1, was also determined by NG Capture-C.
A sister of NANOG regulates genes expressed in pre-implantation human development
We examined the ability of human NANOGNB to regulate gene expression by ectopically expressing the gene in human dermal fibroblasts.
cTag-PAPERCLIP Reveals Alternative Polyadenylation Promotes Cell-Type Specific Protein Diversity and Shifts Araf Isoforms with Microglia Activation
Alternative polyadenylation (APA) is increasingly recognized to regulate gene expression across different cell-types, but obtaining APA maps from individual cell-types typically requires prior purification, a stressful procedure that can itself alter cellular states. Here, we describe a new platform, cTag-PAPERCLIP, that generates APA profiles from single cell populations in intact tissues; cTag-PAPERCLIP requires no tissue dissociation and preserves transcripts in native states. Applying cTag-PAPERCLIP to profile four major cell-types in the mouse brain revealed common APA preferences between excitatory and inhibitory neurons distinct from astrocytes and microglia, regulated in part by neuron-specific RNA-binding proteins NOVA2 and PTBP2. We further identified a role of APA in switching Araf protein isoforms during microglia activation, impacting production of downstream inflammatory cytokines. Our results demonstrate the broad applicability of cTag-PAPERCLIP and a previously undiscovered role of APA in contributing to protein diversity between different cell-types and cellular states within the brain.
S-adenosylhomocysteine hydrolase participates in DNA methylation inheritance
DNA (cytosine-5) methyltransferase 1 (DNMT1) is essential for mammalian development and maintenance of DNA methylation following DNA replication in cells. The DNA methylation process generates S-adenosyl-L-homocysteine, a strong inhibitor of DNMT1. Here we report that S-adenosylhomocysteine hydrolase (SAHH), the only mammalian enzyme capable of hydrolyzing S-adenosyl-L-homocysteine binds to DNMT1 during DNA replication. SAHH activates DNMT1 in vitro and its overexpression in mammalian cells leads to hypermethylation of the genome, whereas its inhibition by adenosine periodate resulted in hypomethylation of the genome. Hypermethylation was consistent in both gene bodies and repetitive DNA elements leading to both down- and up-regulation of genes. Similarly, hypomethylation led to both up- and down-regulation of genes suggesting methylated regions influence gene expression either positively or negatively. Cells overexpressing SAHH specifically up-regulated metabolic pathway genes and down-regulated PPAR and MAPK signaling pathways genes. Therefore, we suggest that alteration of SAHH level in the cell leads to aberrant DNA methylation, altered metabolite levels and gene expression.
Expression data from mammary gland during pregnancy and lactation of CBA/CaH, QSi5 and Advanced Intercross Line (AIL; CBA/CaH X QSi5, the 14th generation)
Previously we have shown significant differences in lactation performance, mammary gland histology and expression profiles of mammary transcriptome during peak-lactation (lactation day 9; L9) between the ordinary CBA/CaH (CBA) and the superior QSi5 strains of mice. In the present study, we compared mammary gland histology between CBA and QSi5 at mid-pregnancy (pregnancy day 12; P12). We assessed lactation performance during the first 8 days of lactation of the 13th - 14th generation of the Advanced Intercross Line (AIL) (CBA X QSi5) mice. We utilized an integrative approach to analyzing mammary microarray expression profiles of CBA and QSi5 at P12 and CBA, AIL and QSi5 at L9.
Differentiating Staphylococcus aureus from Escherichia coli mastitis: S. aureus triggers unbalanced immune-dampening and host cell invasion immediately after udder infection
Outcome and resolution of an udder inflammation (mastitis) depends on the type of the invading pathogen. Gram-negative pathogens, such as Escherichia coli mostly trigger strong inflammation and full local activation of the immune defense eventually resulting in pathogen elimination. Staphylococcus aureus and other Gram-positive pathogens elicit only weak immune reactions possibly allowing for pathogen persistence. Little is known about the very early molecular determinants of this pathogen-species specific immune response of the udder. We therefore infected healthy mid-lactating heifers with a high dose of defined E. coli1303 or S. aureus1027 pathogens, sampled udder tissues at 1, 2, and 3 h post infection and globally profiled the transcriptome of samples from the gland cistern. We expectedly found that the E. coli infection elicited a fast and strong immune response. Bioinformatics analyses suggested that pathogen recognizing receptors triggered the activation of the IkB/NF-kB signaling cascade inducing the expression of a wealth of inflammation related genes, but also many immune dampeners. S. aureus infection failed to elicit inflammation and activate IkB/NF-kB signaling. Instead, it triggered immune suppressive mechanisms which were, however not outweighed by strong induction of inflammatory genes. Moreover, it activated the wnt/b-catenin signaling cascade resulting in active suppression of NF-kB signaling and rearrangement of the actin-cytoskeleton through modulating expression of the Rho GTPases. These alterations facilitate invasion of pathogens into host cells. We validated experimentally that pathogenic S. aureus, but not E. coli may invade mammary epithelial cells (MEC). Microscopy revealed an altered structure of the actin-cytoskeleton of primary MEC having internalized live GFP-tagged S. aureus pathogens. Our study reveals for the first time the earliest host responses in the udder differentiating E. coli from S. aureus mastitis. The latter is characterized by eliciting immune suppression rather than inflammation and invasion of S. aureus into the epithelial cells of the host.
BET-Bromodomain Inhibitors Engage The Host Immune System And Regulate Expression Of The Immune Checkpoint Ligand PD-L1 [3mRNA-seq]
BET inhibitors (BETi) target bromodomain-containing proteins and are currently being evaluated as anti-cancer agents. We discovered that the maximal therapeutic effects of BETi in a Myc-driven B cell lymphoma model required an intact host immune system. Genome-wide analysis of the BETi induced transcriptional response identified the immune checkpoint ligand Cd274 (Pd-l1) as a Myc-independent, BETi target-gene. BETi directly repressed constitutively expressed and IFN-γ induced CD274 expression across different human and mouse tumor cell lines and primary patient samples. Mechanistically, BETi decreased Brd4 occupancy at the Cd274 locus without any change in Myc occupancy, resulting in transcriptional pausing and rapid loss of Cd274 mRNA production. Finally, targeted inhibition of the PD1/PD-L1 axis by combining anti-PD1 antibodies and the BETi JQ1 caused synergistic responses in mice bearing Myc-driven lymphomas. Our data uncovers a novel interaction between BETi and the PD-1/PD-L1 immune-checkpoint and provides novel insight into the transcriptional regulation of CD274.
Expression data from Glioma-Initiating Cells (GICs) cultured under hypoxia and normoxia
Glioblastoma (GBM) is the most common and aggressive primary brain tumor in adults, with glioma initiating cells (GICs) implicated to be critical for tumor progression and resistance to therapy. The hypoxic tumor microenvironment has been shown to play an important role to maintain the GICs; however, the mechanisms regulating responses of GICs to hypoxia remain poorly understood. We used microarray to to detail the global change of gene expression in GICs cultured under hypoxia compared to normoxia and identified de-regulated genes during hypoxia.
SIRT6 is Essential for Adipocyte Differentiation through Regulating Mitotic Clonal Expansion
Preadipocytes initiate differentiation into adipocytes through a cascade of events. Mitotic clonal expansion, as one of the earliest event, is essential for adipogenesis. However, the underlying mechanisms that regulate mitotic clonal expansion remain elusive. SIRT6 is a member of the evolutionarily conserved sirtuin family of NAD+ dependent protein deacetylases and plays roles in genomic stability, aging, glucose metabolism and inflammatory response. Here, we show that SIRT6 deficiency in preadipocytes blocked their adipogenesis. Analysis of gene expression during adipogenesis reveals that KIF5C, which belongs to kinesin family, is negatively regulated by SIRT6. Furthermore, we show that KIF5C is a negative factor for adipogenesis through interacting with CK2α’, a catalytic subunit of CK2. This interaction blocks CK2α’ nuclear translocation and CK2 kinase activity, and inhibits mitotic clonal expansion during adipogenesis. Thus, SIRT6 acts as an important factor of adipogenesis through inhibiting KIF5C expression and enhancing CK2 kinase activity.
RhoA Determines Lineage Fate of MSCs by Modulating CTGF-VEGF Complex in Extracellular Matrix
Mesenchymal stem cells (MSCs) participate in the repair/remodeling of many tissues, where MSCs commit to different lineages dependent on the cues in the local microenvironment. Here we show that TGFβ-activated RhoA/ROCK functions as a molecular switch regarding the fate of MSCs in arterial repair/remodeling after injury. MSCs differentiate into myofibroblasts when RhoA/ROCK is turned on, endothelial cells when turned off. The former is pathophysiologic resulting in intimal hyperplasia, whereas the latter is physiological leading to endothelial repair. Further analysis revealed that MSC RhoA activation promotes formation of an extracellular matrix (ECM) complex consisting of connective tissue growth factor (CTGF) and vascular endothelial growth factor (VEGF). Inactivation of RhoA/ROCK in MSCs induces matrix metalloproteinase-3-mediated CTGF cleavage, resulting in VEGF release and MSC endothelial differentiation. Our findings uncover a novel mechanism by which cell-ECM interactions determine stem cell lineage specificity and offer additional molecular targets to manipulate MSC-involved tissue repair/regeneration.
Genome-wide identification and characterization of novel lncRNAs in Arabidopsis thaliana
To explore the overall long noncoding RNA (lncRNA) involved in growth and development of Arabidopsis thaliana across the lifespan, we deeply sequenced samples of whole plants from different developmental stages (4 rosette leaves>1mm, 14 rosette leaves>1mm, rosette growth complete, first flower buds visible, flourishing florescence, first silique shattered, senescence) using strand-specific RNA sequencing (ssRNA-seq) menthod. We obtained 28.8 Gb raw data and identified 156 novel lncRNAs (unreported in all public plant lncRNA databases) . We also categorized the novel lncRNAs as intergenic, intronic, antisense, overlapped with perhaps pseudogenes and mRNA based on their location on the Arabidopsis genome. Furthermore, lncRNAs targeted protein-coding genes were predicted and functional annotated. In addition, we constructed a network of interactions between ncRNAs (miRNAs, lncRNA) and mRNAs. Our results suggest that the identified novel lncRNAs are important in modulating development process of Arabidopsis, and provide a rich resource for further research on the function of these novel lncRNAs.
Differential impact of Dicer deficiency on microglia of the developing and adult brain (Bulk RNA-Seq)
Microglia seed the embryonic neuro-epithelium, expand and actively sculpt neuronal circuits in the developing CNS, but eventually adopt relative quiescence and ramified morphology in the adult. Here we probed the impact of post-transcriptional control by microRNAs (miRNAs) on microglial performance during development and adulthood by generating mice lacking microglial dicer expression at these distinct stages. RNA seq of conditional dicer ablation in adult microglia revealed that miRNAs were required to limit microglial responses to challenge but had only minor changes on non-challenged microglia. Specifically, following peripheral endotoxin exposure of the animals (LPS), Dicer-deficient microglia either from total brain or hippocampus overexpressed pro-inflammatory cytokines and as a result compromised hippocampal neuronal functions. In contrast, prenatal ablation resulted in spontaneous microglia activation and revealed Dicer involvement in DNA repair and preservation of genome integrity. Overall, our study shows miRNA and Dicer regulation of inflammatory response either following challenge in the adult or spontaneously in the newborn microglia. Moreover, Dicer is required for preservation of microglia DNA integrity required for their proliferation, longevity and radioresistance.
Intergenerational programming of hepatic xenobiotic response by paternal Nicotine exposure
Although it is increasingly accepted that some paternal environmental conditions can influence phenotypes in future generations, it generally remains unclear whether the phenotypes induced in offspring represent specific responses to particular aspects of the paternal exposure history, or whether they represent a more generic response to paternal “quality of life”. To establish a paternal effect model based on a known ligand-receptor interaction and thereby enable pharmacological interrogation of the specificity of the offspring response, we explored the effects of paternal nicotine administration on offspring phenotype in mouse. We show that chronic paternal exposure to nicotine prior to reproduction induced a broad protective response to multiple xenobiotics in the next generation. This effect manifested as increased survival following an injection of toxic levels of either nicotine or of cocaine, was specific to male offspring, and was only observed after offspring were first acclimated to sublethal doses of nicotine or cocaine. Mechanistically, the reprogrammed state was characterized by enhanced clearance of nicotine in drug-acclimated animals, accompanied by hepatic upregulation of genes involved in xenobiotic metabolism. Surprisingly, this protective effect could also be induced by paternal exposure to a nicotinic receptor antagonist as well as to nicotine, suggesting that paternal xenobiotic exposure, rather than nicotinic receptor signaling, is likely to be responsible for programming of offspring drug resistance. Taken together, our data show that paternal drug exposure can induce a protective phenotype in offspring by enhancing metabolic tolerance to xenobiotics in the environment.
Gene expression analysis to identify Klf2 target genes in B-cell progenitors [+Klf2]
The sequential activation of distinct developmental gene networks governs the ultimate identity of a cell, but the mechanisms by which downstream programs are activated are incompletely understood. The preB-cell receptor (preBCR) is an important checkpoint of B-cell development and essential for a preB-cell to traverse into an immature B-cell. Here, we show that activation of Mef2 transcription factors by preBCR is necessary for initiating the subsequent genetic network. We demonstrate that B-cell development is blocked at the preB-cell stage in mice deficient for Mef2c and Mef2d transcription factors and that preBCR signaling enhances the transcriptional activity of Mef2c/d through phosphorylation by the ERK5 mitogen activating kinase. This activation is instrumental in inducing Krüppel-like factor 2 and several immediate early genes of the AP1 and Egr family. Finally, we show that Mef2 proteins cooperate with the products of their target genes (Irf4 and Egr2) to induce secondary waves of transcriptional regulation. Our findings uncover a novel role for Mef2c/d in coordinating the transcriptional network that promotes early B-cell development.
Gene expression analysis to identify Klf2 target genes in B-cell progenitors [Klf2_KO]
The sequential activation of distinct developmental gene networks governs the ultimate identity of a cell, but the mechanisms by which downstream programs are activated are incompletely understood. The preB-cell receptor (preBCR) is an important checkpoint of B-cell development and essential for a preB-cell to traverse into an immature B-cell. Here, we show that activation of Mef2 transcription factors by preBCR is necessary for initiating the subsequent genetic network. We demonstrate that B-cell development is blocked at the preB-cell stage in mice deficient for Mef2c and Mef2d transcription factors and that preBCR signaling enhances the transcriptional activity of Mef2c/d through phosphorylation by the ERK5 mitogen activating kinase. This activation is instrumental in inducing Krüppel-like factor 2 and several immediate early genes of the AP1 and Egr family. Finally, we show that Mef2 proteins cooperate with the products of their target genes (Irf4 and Egr2) to induce secondary waves of transcriptional regulation. Our findings uncover a novel role for Mef2c/d in coordinating the transcriptional network that promotes early B-cell development.
Gene expression analysis to identify Mef2c/d target genes in B-cell progenitors
The sequential activation of distinct developmental gene networks governs the ultimate identity of a cell, but the mechanisms by which downstream programs are activated are incompletely understood. The preB-cell receptor (preBCR) is an important checkpoint of B-cell development and essential for a preB-cell to traverse into an immature B-cell. Here, we show that activation of Mef2 transcription factors by preBCR is necessary for initiating the subsequent genetic network. We demonstrate that B-cell development is blocked at the preB-cell stage in mice deficient for Mef2c and Mef2d transcription factors and that preBCR signaling enhances the transcriptional activity of Mef2c/d through phosphorylation by the ERK5 mitogen activating kinase. This activation is instrumental in inducing Krüppel-like factor 2 and several immediate early genes of the AP1 and Egr family. Finally, we show that Mef2 proteins cooperate with the products of their target genes (Irf4 and Egr2) to induce secondary waves of transcriptional regulation. Our findings uncover a novel role for Mef2c/d in coordinating the transcriptional network that promotes early B-cell development.
Gene Expression Comparison of First Passage vs. Primary Human and Mouse Retinal Sphere Cells
The pigmented portion of ciliary epithelium in the adult mammalian eye harbors mitotically quiescent retinal sphere cells, which are capable of self-renewal and differentiating into retinal neurons when assayed in vitro; however, very little is known about the molecular mechanism controlling the proliferation and differentiation of these adult retinal stem cells or their molecular resemblance to mutipotent stem/progenitor cells during early eye development. This experiment studies the gene expression of first passage and primary human and mouse retinal sphere cells. Keywords: other
Gene expression analysis to identify target genes activated after preBCR signaling
The sequential activation of distinct developmental gene networks governs the ultimate identity of a cell, but the mechanisms by which downstream programs are activated are incompletely understood. The preB-cell receptor (preBCR) is an important checkpoint of B-cell development and essential for a preB-cell to traverse into an immature B-cell. Here, we show that activation of Mef2 transcription factors by preBCR is necessary for initiating the subsequent genetic network. We demonstrate that B-cell development is blocked at the preB-cell stage in mice deficient for Mef2c and Mef2d transcription factors and that preBCR signaling enhances the transcriptional activity of Mef2c/d through phosphorylation by the ERK5 mitogen activating kinase. This activation is instrumental in inducing Krüppel-like factor 2 and several immediate early genes of the AP1 and Egr family. Finally, we show that Mef2 proteins cooperate with the products of their target genes (Irf4 and Egr2) to induce secondary waves of transcriptional regulation. Our findings uncover a novel role for Mef2c/d in coordinating the transcriptional network that promotes early B-cell development.
Differential impact of Dicer deficiency on microglia of the developing and adult brain (Agilent miRNA microarrays)
Microglia seed the embryonic neuro-epithelium, expand and actively sculpt neuronal circuits in the developing CNS, but eventually adopt relative quiescence and ramified morphology in the adult. Here we probed the impact of post-transcriptional control by microRNAs (miRNAs) on microglial performance during development and adulthood by generating mice lacking microglial dicer expression at these distinct stages. RNA seq of conditional dicer ablation in adult microglia revealed that miRNAs were required to limit microglial responses to challenge but had only minor changes on non-challenged microglia. Specifically, following peripheral endotoxin exposure of the animals (LPS), Dicer-deficient microglia either from total brain or hippocampus overexpressed pro-inflammatory cytokines and as a result compromised hippocampal neuronal functions. In contrast, prenatal ablation resulted in spontaneous microglia activation and revealed Dicer involvement in DNA repair and preservation of genome integrity. Overall, our study shows miRNA and Dicer regulation of inflammatory response either following challenge in the adult or spontaneously in the newborn microglia. Moreover, Dicer is required for preservation of microglia DNA integrity required for their proliferation, longevity and radioresistance.
Human lung MPC
A comparison of gene expression between control versus IPF human lung MPC using human Affy 1.0st chips. This work was funded by grants to S.M. Majka from the NIH R01HL091105 and NIH R01HL11659701. Additional funding was also provided by PPG-5P01HL108800-04 (PI:J. Loyd). Experiments were performed using the University of Colorado Cancer Center Microarray core (NCI P30 CA 46934-14). The project was supported in part by the National Center for Research Resources, Grant UL1 RR024975-01, and is now at the National Center for Advancing Translational Sciences, Grant 2 UL1 TR000445-06.
Epigenetic mechanisms underlie the crosstalk between growth factors and a steroid hormone [RNA polymerase ChIP-Seq]
Growth factors (GFs) suppression by steroid hormones recurs in embryology and is co-opted in pathology. While studying mammary cell migration, which is stimulated by GFs and antagonized by glucocorticoids (GCs), we found that GCs inhibit positive feedback loops activated by GFs and stimulate the reciprocal negative loops. Although no alterations in DNA methylation accompany the transcriptional events instigated by either stimulus, forced demethylation of distal regions broadened the repertoire of inducible genes. Our data indicate that the crosstalk involve transcription factors like p53 and NF-kB, along with reduced pausing (and traveling) of RNA polymerase II (RNAPII) at the promoters (and bodies) of GF-inducible genes. In addition, while GFs hyper-acetylated chromatin at unmethylated promoters and enhancers of genes involved in motility, GCs hypo-acetylated the corresponding regions. In conclusion, stably unmethylated genomic regions that encode feedback regulatory modules and differentially recruit RNAPII and acetylases/deacetylases underlie suppression of growth factor signaling by glucocorticoids.
Comparison of Yersinia pestis from rat buboes and laboratory cultures
Yersinia pestis causes bubonic plague in humans and rats. The disease is characterized by an enlarged, painful lymph node, termed a bubo, that develops following bacterial dissemination from an intradermal flea bite injection site. In susceptible animals, the bacteria quickly overcome host innate immune defenses in the lymph node, spread systemically through the blood, and produce fatal sepsis 1,2. At the terminal stage of disease, the bubo contains massive numbers of extracellular bacteria, necrotic lymphoid tissue, hemorrhage, and fibrin 2. The extreme virulence of Y. pestis has been largely ascribed to its ability to avoid innate immunity by preventing phagocytosis, selectively killing immune cells, and down regulating the proinflammatory response 3. Here we report that two innate immune effector mechanisms are generated during bubonic plague in the rat: iron limitation and nitrosative stress. The expression of nitric oxide synthase (iNOS) by rat polymorphonuclear neutrophils (PMNs) was induced in the bubo, and mutation of the Y. pestis hmp gene, which encodes a flavohemoglobin important for resistance to nitric oxide (NO), attenuated virulence. Thus, although Y. pestis avoids uptake and intracellular killing by phagocytes, it still encounters innate immune effector molecules, particularly phagocyte-derived reactive nitrogen species, in the extracellular environment of the bubo. Keywords: repeat
Complementary Post Transcriptional Regulatory Information is Detected by PUNCH-P and Ribosome Profiling
Two novel approaches were recently suggested for genome-wide identification of protein aspects synthesized at a given time. Ribo-Seq is based on sequencing all the ribosome protected mRNA fragments in a cell, while PUNCH-P is based on mass-spectrometric analysis of only newly synthesized proteins. Here we describe the first Ribo-Seq/PUNCH-P comparison via the analysis of mammalian cells during the cell-cycle for detecting relevant differentially expressed genes between G1 and M phase. Our analyses suggest that the two approaches significantly overlap with each other. However, we demonstrate that there are biologically meaningful proteins/genes that can be detected to be post-transcriptionally regulated during the mammalian cell cycle only by each of the approaches, or their consolidation. Such gene sets are enriched with proteins known to be related to intra-cellular signalling pathways such as central cell cycle processes, central gene expression regulation processes, processes related to chromosome segregation, DNA damage, and replication, that are post-transcriptionally regulated during the mammalian cell cycle. Moreover, we show that combining the approaches better predicts steady state changes in protein abundance. The results reported here support the conjecture that for gaining a full post-transcriptional regulation picture one should integrate the two approaches.
Biceps femoris muscle transcriptome in pure and crossbred Iberian pigs at birth
Iberian ham production includes both purebred (IB) and Duroc-crossbred (IBxDU) Iberian pigs, which show important differences in meat quality and production traits, such as muscle growth and fatness. This experiment was conducted to investigate gene expression differences, transcriptional regulation and genetic polymorphisms that could be associated with the observed phenotypic differences between IB and IBxDU pigs. Nine IB and 10 IBxDU pigs were slaughtered at birth. Morphometric measures and blood samples were obtained and samples from Biceps femoris muscle were employed for compositional and transcriptome analysis by RNA-Seq technology. Phenotypic differences were evident at this early age, including greater body size and weight in IBxDU and greater Biceps femoris intramuscular fat and plasma cholesterol content in IB newborns. We detected 150 differentially expressed genes between IB and IBxDU neonates (p 1. 5). Several were related to adipose and muscle tissues development (DLK1, FGF21 or UBC). The functional interpretation of the transcriptomic differences revealed enrichment of functions and pathways related to lipid metabolism in IB and to cellular and muscle growth in IBxDU. Protein catabolism, cholesterol biosynthesis and immune system were functions enriched in both genotypes. We identified transcription factors potentially affecting the observed gene expression differences. Some of them have known functions on adipogenesis (CEBPA, EGRs), lipid metabolism (PPARGC1B) and myogenesis (FOXOs, MEF2D, MYOD1), which suggest a key role in the meat quality differences existing between IB and IBxDU hams. We also identified several polymorphisms showing differential segregation between IB and IBxDU pigs. Among them, non-synonymous variants were detected in several transcription factors as PPARGC1B gene, which could be associated to altered gene function. Taken together, these results provide information about candidate genes, metabolic pathways and genetic polymorphisms potentially involved in phenotypic differences between IB and IBxDU associated to meat quality and production traits.
VP963/DK1622
Phosphate regulation is complex in the developmental prokaryote Myxococcus xanthus, and requires at least three previously characterized two-component systems (TCS), designated PhoR1-PhoP1, PhoR2-PhoP2, and PhoR3-PhoP3. We report here the identification and characterization of a member of a fourth TCS, designated PhoP4, which shows high sequence similarity to the other three M. xanthus PhoP response regulators. PhoP4 is an orphan response regulator that was identified by yeast 2-hybrid screen as a possible interacting partner of PhoR2. phoP4 insertion mutation and in-frame deletion strains were constructed and assessed for developmental and phosphatase phenotypes, and then compared with the phenotypes previously reported for a _phoR2-phoP2 strain. The data indicate that the phoP4 mutations caused spore viability to be decreased by nearly two orders of magnitude, and reduced all three development-specific phosphatase activities by 80-90% under phosphate-limiting conditions. These phenotypes are stronger than those observed for mutations in the PhoR2-PhoP2 system, thereby suggesting a high degree of complexity vis-à-vis the interactions amongst the Pho signal transduction pathways in M. xanthus. Keywords: developmental analysis
A network including TGFβ/Smad4, Gata2 and p57 regulates proliferation of mouse hematopoietic stem/progenitor cells [expression]
Transforming growth factor-β (TGFβ) is a potent inhibitor of hematopoietic stem cell (HSC) proliferation. However, the precise mechanism for this effect is unknown. Here, we have identified the transcription factor Gata2, previously described as an important regulator of HSC function, as an early and direct target gene for TGFβ-induced Smad signaling in hematopoietic stem and progenitor cells (HSPCs). Interestingly, TGFβ-induced Gata2 upregulation is critical for subsequent transcriptional activation of the TGFβ signaling effector molecule p57 and resulting growth arrest of HSPCs. Importantly, both Gata2 and p57 are abundantly expressed in freshly isolated highly purified HSCs, demonstrating the relevance of this circuit in HSC regulation within the HSC niche. Our results connect key molecules involved in HSC self-renewal and reveal a functionally relevant network regulating proliferation of primitive hematopoietic cells. To identify early gene targets of TGFβ signaling in hematopoietic progenitor cells, we performed high-throughput gene expression profiling of a primitive murine hematopoietic cell line. One of the revealed target genes was the transcription factor Gata2, which became the base for the rest of the study.
Histone acetylation during seed germination
Histone acetylation is involved in the regulation of gene expression in plants and eukaryotes. Histone deacetylases (HDACs) are enzymes that catalyze the removal of acetyl groups from histones, which is associated with the repression of gene expression. To study the role of histone acetylation in the regulation of gene expression during seed germination, trichostatin A (TSA), a specific inhibitor of histone deacetylase, was used to treat imbibing Arabidopsis thaliana seeds. GeneChip arrays were used to show that TSA induces up-regulation of 45 genes and down-regulation of 27 genes during seed germination. Eight TSA-up-regulated genes were selected for further analysis - RAB18, RD29B, ATEM1, HSP70 and four late embryogenesis abundant protein genes (LEA). A gene expression time course shows that these eight genes are expressed at high levels in the dry seed and repressed upon seed imbibition at an exponential rate. In the presence of TSA, the onset of repression of the eight genes is not affected but the final level of repressed expression is elevated. Chromatin immunoprecipitation and HDAC assays show that there is a transient histone deacetylation event during seed germination at one day after imbibition, which serves as a key developmental signal that affects the repression of the eight genes. This SuperSeries is composed of the SubSeries listed below.
CD36 deficiency causes intestinal extracellular matrix disruption and chronic neutrophil
BACKGROUND & AIMS: The scavenger receptor CD36 has versatile immuno-metabolic actions. CD36 is abundantly expressed in the small intestinal epithelium but its impact on gut homeostasis is unknown. METHODS: Wild type (WT) and CD36-null (CD36KO) mice were fed a chow diet and small intestinal morphology assessed by immunohistochemistry and electron microscopy (EM). Inflammation was evaluated from neutrophil infiltration, expression of cytokines and toll-like receptors. Barrier integrity was determined using FITC-dextran and circulating lipopolysaccharide (LPS). Enterocyte (Ent-CD36KO) and endothelial (EC-CD36KO) CD36 null mice were generated to test contribution of epithelial versus endothelial CD36 to the intestinal phenotype. RESULTS: The small intestine of CD36KO mice fed a chow diet showed abnormal remodeling of the extracellular matrix (ECM) with altered expression of ECM and junction proteins. Hypertrophy of cell junctions and basement membranes was observed by EM. The CD36KO intestines displayed neutrophil infiltration, inflammation and compromised barrier function. Systemic leukocytosis and neutrophilia were present in CD36KO mice and there was 80% reduction of anti-inflammatory Ly6Clow monocytes important for ECM regulation and tissue repair. Bone marrow transplants supported primary contribution of tissue injury in initiation of inflammation. Studies with Ent-CD36KO mice did not support a major contribution of enterocyte CD36 while endothelial CD36 deficiency associated with neutrophil infiltration, aberrant expression of tight junctions and inflammation in the small intestine. CONCLUSION: CD36 is important for maintenance of barrier function in the small intestine. CD36 deletion causes ECM remodeling with collagen accumulation, depletion of the Ly6Clow monocyte subset and chronic inflammation. Endothelial but not enterocyte CD36 loss is a significant contributor to the spontaneous inflammation.
Identification and characterization of circular RNAs as a new class of putative biomarkers in human blood
Covalently closed circular RNA molecules (circRNAs) have recently emerged as a class of RNA isoforms with widespread and tissue specific expression across animals, oftentimes independent of the corresponding linear mRNAs. circRNAs are remarkably stable and sometimes highly expressed molecules. Here, we sequenced RNA in human peripheral whole blood to determine the potential of circRNAs as biomarkers in an easily accessible body fluid. We report the reproducible detection of thousands of circRNAs. Importantly, we observed that hundreds of circRNAs are much higher expressed than corresponding linear mRNAs. Thus, circRNA expression in human blood reveals and quantifies the activity of hundreds of coding genes not accessible by classical mRNA specific assays. Our findings suggest that circRNAs could be used as biomarker molecules in standard clinical blood samples.
Comparison between naïve, tolerant and memory CD8+ T cells
To elucidate transcriptional differences between naïve, tolerant and memory CD8+ T cells, genome-wide gene expression profiling was performed. The indicated cell populations were purified from immunized or naïve Rag-/- TCR mice by cell sorting and RNA was extracted labeled and hybridized to an Affymetrix custom mouse array GNF1M GeneChip. RNA from sorted samples was prepared, split into two aliquots prior to making labeled cDNA, so that two arrays were used for each cell population.Alterations in transcript levels were determined through pair wise comparisons of naïve cells to either memory or tolerant CD8+ T cells. Keywords: cell type
Differential gene expression of endosphere and soil Bacillus mycoides isolate in response to root exudates using RNA sequencing
In general, the endosphere isolate EC18 showed more numbers of genes significantly altered in the presence of root exudates than the soil isolate SB8 . Some of the altered genes in the two strains showed overlap. Some of these genes were previously reported to be involved in microbe-plant interactions, such as organic substance metabolism, oxidation reduction, transmembrane transportation and a subset with putative or unknown function. It was also found some genes showed opposite trend among the two strains.
Expression and Splicing of ABC and SLC Transporters in the Blood-Brain Barrier
The low permeability and high selectivity of the blood vessels of the brain and central nervous system (CNS) characterize the blood-brain barrier (BBB). Tight junctions, a lack of fenestrations, and low rates of transcytosis in the endothelial cells of the vasculature prevent passive diffusion of most molecules other than water, gases and some lipid soluble molecules (Obermeier, Daneman, & Ransohoff, 2013). Any additional nutrients must be transported across the barrier with the help of transporter proteins. Two protein families account for most transporters. ABC transporters use ATP to power primary-active transport to move molecules across the BBB against an electrochemical gradient, frequently excluding drugs from entering the brain. Some SLC transporters facilitate transport of solutes along an electrochemical gradient, while others permit secondary-active transport by coupling the flow of a solute traveling down the electrochemical gradient to power another solute against its electrochemical gradient. Brain microvessel endothelial cells (BMEC) from human cerebral cortex were enriched through a homogenization and centrifugation procedure. Two BMEC and two tissue were sequenced with paired-end reads on a SOLiD 5500 Wildfire. Raw data was aligned using LifeScope Genomic Analysis, gene expression determined through Cufflinks, and splice junctions identified by aligning to a custom database of known to known and known to novel junctions. We found numerous examples of transporters with enriched expression in the isolated BMECs compared to whole brain tissue. In total, 131 transporter genes or pseudogenes (109 SLC, 22 ABC) are enriched at least 1.25 fold in BMEC enriched samples, and 57 of these are enriched over 2-fold (50 SLC, 7 ABC). Thirteen genes were found to have at least twice as many counts in BMEC enriched samples than in whole tissue for at least one alternative splice junction. Inversely, 23 genes were found to have at least one alternative splice junction with half as many counts in BMEC enriched samples than in whole tissue.
TUMOR INITIATING CELLS AND IGF/FGF SIGNALING CONTRIBUTE TO SORAFENIB RESISTANCE IN HEPATOCELLULAR CARCINOMA
OBJECTIVE: Sorafenib is effective in hepatocellular carcinoma (HCC), but patients ultimately present disease progression. Molecular mechanisms underlying acquired resistance are still unknown. Herein, we characterize the role of tumor-initiating cells (T-ICs) and signaling pathways involved in sorafenib resistance. DESIGN: HCC xenograft mice treated with sorafenib (n=22) were explored for responsiveness (n=5) and acquired resistance (n=17). Mechanism of acquired resistance were assessed by: 1) Role of T-ICs by in vitro sphere formation and in vivo tumorigenesis assays using NOD/SCID mice, 2) Activation of alternative signaling pathways and 3) Efficacy of anti-FGF and anti-IGF drugs in experimental models. Gene expression (microarray, qRT-PCR) and protein analyses (immunohistochemistry, western blot) were conducted. A novel gene signature of sorafenib resistance was generated and tested in 2 independent cohorts. RESULTS: Sorafenib-acquired resistance tumors showed significant enrichment of T-ICs (164 cells needed to create a tumor) vs. sorafenib-sensitive tumors (13400 cells) and non-treated tumors (1292 cells), p<0.001. Tumors with sorafenib-acquired resistance were enriched with IGF and FGF signaling cascades (FDR<0.05). In vitro, cells derived from sorafenib-acquired resistant tumors and two sorafenib-resistant HCC cell lines were responsive to IGF or FGF inhibition. In vivo, FGF blockade delayed tumor growth and improved survival in sorafenib-resistant tumors. A sorafenib-resistance 175-gene signature was characterized by enrichment of progenitor-cell features, aggressive tumoral traits and predicted poor survival in 2 cohorts (n=442 HCC patients). CONCLUSION: Acquired resistance to sorafenib is driven by tumor initiating cells with enrichment of progenitor markers and activation of IGF and FGF signaling. Inhibition of these pathways would benefit a subset of patients after sorafenib progression.
Reprogramming of H3K9me3-dependent heterochromatin during mammalian early embryo development [ChIP-seq]
H3K9me3-dependent heterochromatin is considered as one of the major barriers for cell fate changes, and must be reprogrammed during fertilization to reactivate highly specialized paternal and maternal genome to establish totipotency. However, the molecular details are lacked for early embryos due to the limited materials. Here we map the genome-wide distribution of H3K9me3 modification in the early embryo as well as in the cell fate determined embryonic tissues after implantation. We find that H3K9me3 exhibits distinct dynamic features in promoters and retro-transposons. Both maternal and paternal genome undergo large scale of H3K9me3 reestablishment after fertilization, and the imbalance of maternal H3K9me3 signal over paternal last until the blastocyst stage. The rebuilding of H3K9me3 on LTR retro-transposons maintains its repression state after the global DNA demethylation, and we further discover that Chaf1a is essential for the establishment of H3K9me3 on LTRs and the loss function of Chaf1a leads to embryo development failure. Finally, we find that lineage specific H3K9me3 is established after lineage commitment in post-implantation embryos. Thus, our data demonstrate that H3K9me3-dependent heterochromatin undergoes dramatic reprogramming during early embryo development and the establishment of H3K9me3 on LTRs is essential for proper embryo development.
Classification of pediatric acute myeloid leukemia based on miRNA expression profiles
Pediatric acute myeloid leukemia (AML) is a heterogeneous disease with respect to biology as well as outcome. In this study, we investigated whether known biological subgroups of pediatric AML are reflected by a common microRNA (miRNA) expression pattern. We assayed 665 miRNAs in 165 pediatric AML samples. First, unsupervised clustering was performed to identify patient clusters with common miRNA expression profiles. Our analysis unraveled 14 clusters, seven of which had a known (cyto-)genetic denominator. Finally, a robust classifier was constructed to discriminate six known molecular aberration groups: 11q23-rearrangements, t(8;21)(q22;q22), inv(16)(p13q22), t(15;17)(q21;q22), NPM1 and CEBPA mutations. The classifier achieved accuracies of 89%, 95%, 95%, 98%, 91% and 96%, respectively. Although lower sensitivities were obtained for the NPM1 and CEBPA (32% and 66%), relatively high sensitivities (84%-94%) were attained for the rest. Specificity was high in all groups (87%-100%). Due to a robust double-loop cross validation procedure we employed, the classifier only used expression of 47 miRNAs to generate the aforementioned accuracies. To validate the 47 miRNA signatures, we applied them to a publicly available adult AML dataset. Despite partial overlap of miRNA platforms and known molecular differences between pediatric and adult AML, the signatures performed reasonably well. This corroborates our claim that the reported miRNA signatures are not dominated by sample size bias in the pediatric AML dataset. We conclude that cytogenetic subtypes of pediatric AML have distinct miRNA expression patterns. Note that, reproducibility of the miRNA signatures in adult dataset suggests that the respective aberrations have a similar biology both in pediatric and adult AML
Hypothalamic reprogramming by sperm microRNA
Nine microRNAs (miRs) previously identified as increased in the sperm of stressed sires were microinjected into C57/Bl6:129S6/SvEvTac mouse single cell zygotes to examine the hypothesis that specific sperm miRs function postfertilization to alter offspring stress responsivity. Derived mice were exmined for hypothalamic-pituitary-adrenal axis stress response in adulthood, and the paraventricular nucleus of the hypothalamus was subsequently collected for gene expression analysis by next gen sequencing. Similar to what we reported previously in our paternal stress model, the majority of diffferenitally expressed genes in the PVN exhibited decreased expression, supporting that an increase of specific sperm miRs in the zygote can elicit long-term genetic reprogramming. Futher, marked changes in the expression of extracellular matrix and collagen gene sets suggested altered blood-brain barrier permeability with potential consequences for neuroendocrine function.