Project description:Pitx2 is the homeobox gene located in proximity to the human 4q25 familial atrial fibrillation locus. Pitx2 haploinsufficient mice are prone to pacing induced atrial fibrillation indicating that reduced Pitx2 promotes an arrhythmogenic substrate within the atrium. Here, we inactivated Pitx2 in postnatal heart and discovered that unstressed adult Pitx2 mutant mice had sinus node dysfunction with impaired atrial conduction, an arrhythmia closely associated with atrial fibrillation. A genome-wide search for Pitx2 transcriptional targets using ChIP-sequencing and RNA expression profiling shows that Pitx2 represses target genes encoding cell junction proteins, ion channels, and critical transcriptional regulators many of which have been implicated in human atrial fibrillation by genome wide association studies. Our findings unveil a Pitx2 postnatal arrhythmogenic function, novel Pitx2 target genes relevant to atrial fibrillation, and reveal that Pitx2 stabilizes the intercalated disc in postnatal atrium. Genomic occupancy profiling of transcriptional factor Pitx2 in postnatal heart.
Project description:ChIP-seq analysis of HepG2 cells revealed that many of the target genes of LSD2 were related to lipid metabolism. We found that LSD2 is an important epigenetic regulator of hepatic lipid metabolism. Examination of LSD2/DNA interaction in HepG2 cells in normal condition.
Project description:ChIP-seq analysis of LSD2-depleted HepG2 cells revealed that many of the target genes were related to lipid metabolism. We found that LSD2 is an important epigenetic regulator of hepatic lipid metabolism. Examination of LSD2/H3K4me1 interaction in control and LSD2-knockdowned HepG2 cells.
Project description:Methylated DNA immunoprecipitation sequencing (MeDIP-Seq) is a widely used approach to study DNA methylation genome-wide. Here, we present a novel MeDIP-Seq protocol compatible with the Ion Torrent semiconductor-based sequencing platform that is scalable and accurately identifies sites of differential DNA methylation. Additionally, we demonstrate that the high-throughput data derived from MeDIP-Seq on the Ion Torrent platform provides adequate coverage of CpG cytosines, the methylation states of which we validated at single-base resolution on the Infinium HumanMethylation450K Beadchip array. We applied this integrative approach to further investigate the role of DNA methylation in alternative splicing and to profile 5-mC and 5-hmC variants of DNA methylation in normal human brain tissue that we observed localize over distinct genomic regions. These applications of MeDIP-Seq on the Ion Torrent platform have broad utility and add to the current methodologies for profiling genome-wide DNA methylation states in normal and disease conditions. MeDIP-Seq on Ion Torrent Platform in HCT116 and Human Brain
Project description:Pitx2 is the homeobox gene located in proximity to the human 4q25 familial atrial fibrillation locus. Pitx2 haploinsufficient mice are prone to pacing induced atrial fibrillation indicating that reduced Pitx2 promotes an arrhythmogenic substrate within the atrium. Here, we inactivated Pitx2 in postnatal heart and discovered that unstressed adult Pitx2 mutant mice had sinus node dysfunction with impaired atrial conduction, an arrhythmia closely associated with atrial fibrillation. A genome-wide search for Pitx2 transcriptional targets using ChIP-sequencing and RNA expression profiling shows that Pitx2 represses target genes encoding cell junction proteins, ion channels, and critical transcriptional regulators many of which have been implicated in human atrial fibrillation by genome wide association studies. Pitx2 control and mutant hearts were collected from 3-, 6- and 12-week-old mice. At each time point, three cotrols and three mutants were collected as biological replicates. cDNA microarray analysis was performed using Affymetrix GeneChip Mouse Genome 430 2.0 Array (Affymetrix, Santa Clara, CA).
Project description:LHY and CCA1 encode single MYB transcription factors, involved in circadian clock. However, direct target genes of LHY and CCA1 in a genomic scale were largely unknown. To reveal bound genes by CCA1, chimeric protein CCA1-FLAG was expressed under CCA1 promoter in cca1 lhy (CCA1pro:CCA1-FLAG/ cca1 lhy). ChIP was performed using anti-FLAG antibody (F3165; SIGMA), which was bound to Dynabeads Protein G (100-03D; Life Technologies), and ChIP DNA were analyzed by IonPGM or Illumina GAII. Chromatin immunoprecipitation was performed for CCA1-FLAG-expressing Arabidopsis. ChIP DNA was analyzed 2 types of deep sequencers (Illumina GAII and IonPGM).
Project description:Background: Microorganisms are the major cause of food spoilage during storage, processing and distribution. Pseudomonas fluorescens is a typical spoilage bacterium that contributes to a large extent to the spoilage process of proteinaceous food. RpoS is considered an important global regulator involved in stress survival and virulence in many pathogens. Our previous work revealed that RpoS contributed to the spoilage activities of P. fluorescens by regulating resistance to different stress conditions, extracellular acylated homoserine lactone (AHL) levels, extracellular protease and total volatile basic nitrogen (TVB-N) production. However, RpoS-dependent genes in P. fluorescens remained undefined. Results: RNA-seq transcriptomics analysis combined with quantitative proteomics analysis basing on multiplexed isobaric tandem mass tag (TMT) labeling was performed for the P. fluorescens wild-type strain UK4 and its derivative carrying a rpoS mutation. A total of 375 differentially expressed genes (DEGs) and 212 differentially expressed proteins (DEPs) were identified in these two backgrounds. The DGEs were further verified by qRT-PCR tests, and the genes directly regulated by RpoS were confirmed by 5’-RACE-PCR sequencing. The combining transcriptome and proteome analysis revealed a role of this regulator in several cellular processes, including polysaccharide metabolism, intracellular secretion and extracellular structures, cell well biogenesis, stress responses, ammonia and biogenic amine production, which may contribute to biofilm formation, stress resistance and spoilage activities of P. fluorescens. Moreover, in this work we indeed observed that RpoS contributed to the production of the macrocolony biofilm’s matrix.
Project description:Through the analysis of mouse liver tumours promoted by distinct routes (DEN exposure alone, DEN exposure plus non-genotoxic insult with phenobarbital and non-alcoholic fatty liver disease); we report that the cancer associated hyper-methylated CGI events in mice are also predicated by silent promoters that are enriched for both the DNA modification 5-hydroxymethylcytosine (5hmC) and the histone modification H3K27me3 in normal liver. During cancer progression these CGIs undergo hypo-hydroxymethylation, prior to subsequent hyper-methylation; whilst retaining H3K27me3. A similar loss of promoter-core 5hmC is observed in Tet1 deficient mouse livers indicating that reduced Tet1 binding at CGIs may be responsible for the epigenetic dysregulation observed during hepatocarcinogenesis. Consistent with this reduced Tet1 protein levels are observed in mouse liver tumour lesions. As in human, DNA methylation changes at CGIs do not appear to be direct drivers of hepatocellular carcinoma progression in mice. Instead dynamic changes in H3K27me3 promoter deposition are strongly associated with tumour-specific activation and repression of transcription. Our data suggests that loss of promoter associated 5hmC in diverse liver tumours licences DNA methylation reprogramming at silent CGIs during cancer progression. We carry out 5-hydroxymethylation DNA immunoprecipitation (hmeDIP) prior to sequencing Ion Proton P1 to report on the genome-wide 5hmC patterns. Heterozygote pairs of Tet1 B6;129S4-Tet1tm1.1Jae/J mice were bought from The Jackson Laboratory (Maine USA). Heterozygotes were interbred to produce homozygous knock out males with colony mate wild type controls. Genome-wide 5hmC patterns were generated by hydroxymethyl-DNA immuoprecipitation (hmeDIP) followed by genome wide sequencing on the Ion Proton P1 sequencer.
Project description:Loss of Lsd1 in Drosophila in specific cells of the Drosophila ovary results in increased BMP signaling outside the cap cell niche and an expanded germline stem cell (GSC) phenotype. To better characterize the function of Lsd1 in different cell populations within the ovary, we performed Chromatin immunoprecipitation coupled with massive parallel sequencing (ChIP-seq). This analysis shows that Lsd1 associates with a surprisingly limited number of sites in escort cells and fewer, and often, different sites in cap cells. These findings indicate that Lsd1 displays highly selective binding in specific cellular contexts. Examination of epitope tagged Lsd1 transgenes in specific cell populations within the Drosophila ovary