ABSTRACT: We examine the role of Klf6 in oligodendrocyte progenitor cells and determine that Klf6 acts in part through direct regulation of gp130 signaling and nuclear import via importin-α5 (Impα5), a key controller of nuclear trafficking. Examination of Klf6 DNA binding in two different stages of differentiation
Project description:We examine the role of Klf6 in oligodendrocyte progenitor cells and determine that Klf6 acts as a gp130-sensitive transactivator of the nuclear import factor importin-α5 (Impα5), a key controller of nuclear trafficking in oligodendrocytes. Examination of expression profiles of 2 different cell stages exposed to siRNA vs. control
Project description:We sequenced DNA isolated from performing ChIP of full-length KLF6 and an Input sample in an HCC cell line. The goal is to determine KLF6 binding sites in a mouse-derived HCC cell line. Determination of KLF6 binding sites in an HCC cell line using 2 control input libraries and 2 KLF6-ChIP libraries
Project description:Gene-expression profiles of liver and hepatocellular carcinoma induced by diethylnitrosamine (DEN) in KLF6 +/- and wild type KLF6 mice. Inactivation of the KLF6 tumor suppressor is common in HCC due to hepatitis C virus (HCV), consistent with its anti-proliferative activity in HCC-derived cell lines and in hepatocytes of transgenic mice. We have evaluated the impact of KLF6 depletion on human HCC and experimental hepatocarcinogenesis. In patients with surgically resected HCC, those with significantly reduced tumor expression of KLF6 had a significantly decreased survival. We modeled this event in KLF6 +/- mice, which displayed significantly more tumorigenicity than KLF6 +/+ animals in response to the hepatic carcinogen DEN, associated with recapitulation of gene signatures in both surrounding tissue and tumors that are associated with aggressive human HCCs. In DNA microarrays, mdm2 mRNA expression was increased in tumors from KLF6 +/- compared to KLF6 +/+ mice, which was validated by realtime qPCR and Western blot in both human HCC and DEN-induced murine tumors. Moreover, chromosomal immunoprecipitation and co-transfection assays established the P2 intronic promoter of mdm2 as a bona fide transcriptional target repressed by KLF6. Whereas KLF6 over-expression in HCC cell lines led to reduced MDM2 levels and increased p53 protein and transcriptional activity, reduction in KLF6 by siRNA led to increased MDM2 and reduced p53. Our findings indicate that KLF6 deficiency contributes significantly to the carcinogenic milieu in human and murine HCC, and uncover a novel tumor suppressor activity of KLF6 in HCC, by linking its transcriptional repression of MDM2 to stabilization of p53. Keywords: Liver, Hepatocellular carcinoma, Expression array, Exon array, Affymetrix KLF6 +/- mice were previously generated by homologous recombination in which exon 2 was targeted using an 11-kb targeting construct, and replaced with neomycin/lacZ cassette. After selection with neomycin, the ES clones were injected into C57BL/6 mouse blastocysts and implanted into pseudo pregnant females; two lines of KLF6 +/- mice were generated from the resulting chimeric animals (Blood 107;1357, Oncogene 26;4428). Whereas KLF6 -/- mice are embryonic lethal, KLF6 +/- animals had no demonstrable abnormalities in the absence of any stressor. Male KLF6 +/- mice were bred with wild type C57BL/6 to generate mixed litters of KLF6 +/- and KLF6 +/+ animals. Progeny were genotyped using PCR-amplified tail DNA, using primers as previously described (Oncogene 26;4428). Amplified fragments were separated on a 2.5% agarose gel, revealing bands of ~200 bp (wild type KLF6) and ~100 bp (Neo), as expected. At 2 weeks of age, KLF6 +/+ and KLF6 +/- mice were injected intraperitoneally with either a single dose of diethyl nitrosamine (DEN), 5 µg/g body weight in 100 µl of saline, or vehicle alone. Vehicle and DEN-treated mice were maintained on standard chow, and then sacrificed 3, 6 or 9 months later. At the time of sacrifice the animals were weighed, and blood and liver samples were harvested for analysis and tumor quantification.
Project description:Dysregulated glucose homeostasis and lipid accumulation characterize non-alcoholic fatty liver disease (NAFLD), but underlying mechanisms are obscure. We report here that Krüppel-like factor 6 (KLF6), a ubiquitous transcription factor that promotes adipocyte differentiation, also provokes the metabolic abnormalities of NAFLD. Mice with either hepatocyte-specific knockdown of KLF6 (DeltaHepKlf6) or global KLF6 heterozygosity (Klf6 +/-) have reduced body fat content and improved glucose and insulin tolerance. Mice with KLF6 depletion, compared to wild type mice, are protected from high fat diet-induced steatosis. Three mice with a hepatocyte-specific knockdown of KLF6 (DeltaHepKlf6) on high fat diet and 3 littermate controls on the same diet were sacrificed after 8 weeks of diet. Liver tissue was preserved in RNAlater® (Ambion, Austin, TX). RNA was isolated from liver tissue and homogenized in TRIzol® reagent (Invitrogen, Carlsbad, CA). In order to identify potential KLF6 targets that contributed to changes in glucose- and lipid-metabolism, we performed an Affymetrix Exon1 S.T. Genearray® (Affymetrix, Santa Clara, CA).
Project description:KLF6 was overexpressed using an adenoviral delivery system. Overexpression was confirmed at 12, 24, 48 and 72 hours post infection by RT-PCR and Western Blot analysis. Codelink Whole genome microarrays were used to analyse changes in expression resulting from KLF6 overexpression. RNA Samples were taken at 48 and 72 hours from samples oeverexpressing KLF6 and the empty vector control pBabe
Project description:Polycomb repressive complex 2 (PRC2) controls maintenance and lineage determination of stem cells by suppressing genes that regulate cellular differentiation and tissue development. However, the role of PRC2 in lineage-committed somatic cells is largely unknown. In this study, we ablated Eed, an essential component of PRC2, in growth plate chondrocytes to study the role of PRC2 in skeletal development. In this study, we profiled genes assocaited with H3K27me3 histone 3 modification in primary rib chondrocytes. Mouse primary chodnrocytes were subjected to ChIP analysis using H3K27me3 antibody. ChIP'ed DNA and Input DNA were sequenced by Otogenetics (Necros, GA)
Project description:To investigate the heart development, the data were generated to examine the genome-wide Gli3 binding in SHF disected from Mouse Embryos. Gli3 ChIP-Seq was compared to the input in SHF from mouse embryonic cells at E9.5.
Project description:We demonstrate using conditional mutagenesis that Pbx1, with and without Pbx2+/ sensitization, regulates regional identity and laminar patterning of the developing mouse neocortex in cortical progenitors (Emx1-Cre) and in newly generated neurons (Nex1-Cre). Pbx1/2 mutants have three salient molecular phenotypes of cortical regional and laminar organization: hypoplasia of the frontal cortex, ventral expansion of the dorsomedial cortex, and ventral expansion of Reelin expression in the cortical plate of the frontal cortex, concomitant with an inversion of cortical layering in the rostral cortex. Molecular analyses, including PBX ChIP-seq, provide evidence that PBX promotes frontal cortex identity by repressing genes that promote dorsocaudal fate. Chromatin immunoprecipitation was performed using antibody against Pbx1/2/3/ (sc-888, Santa Cruz). Wild type E12.5 mouse whole cortex was used for the analysis.
Project description:We demonstrate using conditional mutagenesis that Pbx1, with and without Pbx2+/ sensitization, regulates regional identity and laminar patterning of the developing mouse neocortex in cortical progenitors (Emx1-Cre) and in newly generated neurons (Nex1-Cre). Pbx1/2 mutants have three salient molecular phenotypes of cortical regional and laminar organization: hypoplasia of the frontal cortex, ventral expansion of the dorsomedial cortex, and ventral expansion of Reelin expression in the cortical plate of the frontal cortex, concomitant with an inversion of cortical layering in the rostral cortex. Molecular analyses, including PBX ChIP-seq, provide evidence that PBX promotes frontal cortex identity by repressing genes that promote dorsocaudal fate. Chromatin immunoprecipitation was performed using antibody against Pbx1/2/3 (sc-888, Santa Cruz). Wild type E15.5 mouse whole cortex was used for the analysis.
Project description:To test whether nuclear importin alpha2 can regulate transcription, we sought to examine gene expression changes in cells with nuclear accumulation of importin alpha2 by performing microarray analysis. We designed an experiment in which EGFP-fused full-length importin alpha2 was transfected into HeLa cells. To exclude the possibility that exogenous, full-length importin alpha2 protein enhances nuclear transport of karyophilic proteins such as transcription factors and thereby directly influences gene expression, a mutant of importin alpha2 which is mutated in the C-terminal CAS-binding domain was also transfected, so that it is never recycled to the cytoplasm and shows complete nuclear localization. We undertook to investigate whether there were changes in gene expression common to cells expressing the full-length importin alpha2 and the C-terminal mutant (C-mutant) isoform. EGFP vs. EGFP-importin alpha2 full length, or EGFP vs EGFP-importin alpha2 CAS-binding mutant. One replicate each. EGFP-expressing cells are used as a control.