scholarly journals DUX4 expressing immortalized FSHD lymphoblastoid cells express genes elevated in FSHD muscle biopsies, correlating with the early stages of inflammation

2020 ◽  
Vol 29 (14) ◽  
pp. 2285-2299 ◽  
Author(s):  
Christopher R S Banerji ◽  
Maryna Panamarova ◽  
Peter S Zammit
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Target Gene ◽  
Target Genes ◽  
Ectopic Expression ◽  
Lymphoblastoid Cell Lines ◽  
Immune Gene ◽  
Target Gene Expression ◽  
Early Stages ◽  
Muscle Biopsies

Abstract Facioscapulohumeral muscular dystrophy (FSHD) is an incurable disorder linked to ectopic expression of DUX4. However, DUX4 is notoriously difficult to detect in FSHD muscle cells, while DUX4 target gene expression is an inconsistent biomarker for FSHD skeletal muscle biopsies, displaying efficacy only on pathologically inflamed samples. Immune gene misregulation occurs in FSHD muscle, with DUX4 target genes enriched for those associated with inflammatory processes. However, there lacks an assessment of the FSHD immune cell transcriptome, and its contribution to gene expression in FSHD muscle biopsies. Here, we show that EBV-immortalized FSHD lymphoblastoid cell lines express DUX4 and both early and late DUX4 target genes. Moreover, a biomarker of 237 up-regulated genes derived from FSHD lymphoblastoid cell lines is elevated in FSHD muscle biopsies compared to controls. The FSHD Lymphoblast score is unaltered between FSHD myoblasts/myotubes and their controls however, implying a non-myogenic cell source in muscle biopsies. Indeed, the FSHD Lymphoblast score correlates with the early stages of muscle inflammation identified by histological analysis on muscle biopsies, while our two late DUX4 target gene expression biomarkers associate with macroscopic inflammation detectable via MRI. Thus, FSHD lymphoblastoid cell lines express DUX4 and early and late DUX4 target genes, therefore, muscle-infiltrated immune cells may contribute the molecular landscape of FSHD muscle biopsies.

scholarly journals Lymphocytes contribute to DUX4 target genes in FSHD muscle biopsies

2019 ◽  
Author(s):  
Christopher R. S. Banerji ◽  
Maryna Panamarova ◽  
Peter S. Zammit
Keyword(s):  
Gene Expression ◽  
Target Gene ◽  
Target Genes ◽  
Immune Cell ◽  
Facioscapulohumeral Muscular Dystrophy ◽  
Immune Gene ◽  
Target Gene Expression ◽  
Inflammatory Processes ◽  
Cell Transcriptome ◽  
Muscle Biopsies

SummaryFacioscapulohumeral muscular dystrophy (FSHD) is an incurable myopathy linked to overexpression of DUX4. However, DUX4 is difficult to detect in FSHD myoblasts and target gene expression is not a consistent FSHD muscle biopsy biomarker, displaying efficacy only on pathologically inflamed samples. Immune gene misregulation occurs in FSHD muscle biopsies with DUX4 targets enriched for inflammatory processes. However, assessment of the FSHD immune cell transcriptome, and the evaluation of DUX4 and target gene expression has not yet been performed. We show that FSHD lymphoblastoid cell lines (LCLs) display robust DUX4 expression, and express early and late DUX4 targets. Moreover, genes elevated on FSHD LCLs are elevated in FSHD muscle biopsies, correlating with DUX4 target activation and histological inflammation. These genes are importantly unaltered in FSHD myoblasts/myotubes, implying a non-muscle source in biopsies. Our results indicate an immune cell source of DUX4 and target gene expression in FSHD muscle biopsies.

scholarly journals On the way toward regulatable expression systems in acetic acid bacteria: target gene expression and use cases

2021 ◽  
Author(s):  
Philipp Moritz Fricke ◽  
Angelika Klemm ◽  
Michael Bott ◽  
Tino Polen
Keyword(s):  
Gene Expression ◽  
Acetic Acid ◽  
Literature Search ◽  
Target Gene ◽  
Target Genes ◽  
Recombinant Dna ◽  
Acetic Acid Bacteria ◽  
Homoserine Lactone ◽  
Expression Systems ◽  
Target Gene Expression

Abstract Acetic acid bacteria (AAB) are valuable biocatalysts for which there is growing interest in understanding their basics including physiology and biochemistry. This is accompanied by growing demands for metabolic engineering of AAB to take advantage of their properties and to improve their biomanufacturing efficiencies. Controlled expression of target genes is key to fundamental and applied microbiological research. In order to get an overview of expression systems and their applications in AAB, we carried out a comprehensive literature search using the Web of Science Core Collection database. The Acetobacteraceae family currently comprises 49 genera. We found overall 6097 publications related to one or more AAB genera since 1973, when the first successful recombinant DNA experiments in Escherichia coli have been published. The use of plasmids in AAB began in 1985 and till today was reported for only nine out of the 49 AAB genera currently described. We found at least five major expression plasmid lineages and a multitude of further expression plasmids, almost all enabling only constitutive target gene expression. Only recently, two regulatable expression systems became available for AAB, an N-acyl homoserine lactone (AHL)-inducible system for Komagataeibacter rhaeticus and an l-arabinose-inducible system for Gluconobacter oxydans. Thus, after 35 years of constitutive target gene expression in AAB, we now have the first regulatable expression systems for AAB in hand and further regulatable expression systems for AAB can be expected. Key points • Literature search revealed developments and usage of expression systems in AAB. • Only recently 2 regulatable plasmid systems became available for only 2 AAB genera. • Further regulatable expression systems for AAB are in sight.

Mutants of cubitus interruptus that are independent of PKA regulation are independent of hedgehog signaling

Development ◽  
1999 ◽  
Vol 126 (16) ◽  
pp. 3607-3616 ◽  
Author(s):  
Y. Chen ◽  
J.R. Cardinaux ◽  
R.H. Goodman ◽  
S.M. Smolik
Keyword(s):  
Gene Expression ◽  
Target Gene ◽  
Ectopic Expression ◽  
Proteolytic Processing ◽  
Dominant Negative ◽  
Cubitus Interruptus ◽  
Target Gene Expression ◽  
Exogenous Expression

Hedgehog (HH) is an important morphogen involved in pattern formation during Drosophila embryogenesis and disc development. cubitus interruptus (ci) encodes a transcription factor responsible for transducing the hh signal in the nucleus and activating hh target gene expression. Previous studies have shown that CI exists in two forms: a 75 kDa proteolytic repressor form and a 155 kDa activator form. The ratio of these forms, which is regulated positively by hh signaling and negatively by PKA activity, determines the on/off status of hh target gene expression. In this paper, we demonstrate that the exogenous expression of CI that is mutant for four consensus PKA sites [CI(m1-4)], causes ectopic expression of wingless (wg) in vivo and a phenotype consistent with wg overexpression. Expression of CI(m1-4), but not CI(wt), can rescue the hh mutant phenotype and restore wg expression in hh mutant embryos. When PKA activity is suppressed by expressing a dominant negative PKA mutant, the exogenous expression of CI(wt) results in overexpression of wg and lethality in embryogenesis, defects that are similar to those caused by the exogenous expression of CI(m1-4). In addition, we demonstrate that, in cell culture, the mutation of any one of the three serine-containing PKA sites abolishes the proteolytic processing of CI. We also show that PKA directly phosphorylates the four consensus phosphorylation sites in vitro. Taken together, our results suggest that positive hh and negative PKA regulation of wg gene expression converge on the regulation of CI phosphorylation.

The Interaction Between DOT1L and AF10 Is Required for H3K79 Dimethylation and MLL-AF9 Leukemia

Blood ◽  
2012 ◽  
Vol 120 (21) ◽  
pp. 401-401
Author(s):  
Aniruddha J Deshpande ◽  
Liying Chen ◽  
Kathrin M Bernt ◽  
Stuart Dias ◽  
Deepti Banka ◽  
...  
Keyword(s):  
Gene Expression ◽  
Mass Spectrometry ◽  
Target Gene ◽  
Leucine Zipper ◽  
Target Genes ◽  
Fusion Gene ◽  
Transformed Cells ◽  
Target Gene Expression ◽  
Transforming Activity ◽  
H3k79 Methylation

Abstract Abstract 401 MLL-fusion proteins induce changes in histone modifications that result in the abnormal and sustained expression of downstream oncogenic target genes. A number of recent studies have identified aberrant histone 3 lysine 79 (H3K79) methylation by the chromatin modifying enzyme DOT1L as an important epigenetic modification that sustains MLL-target gene expression. Aberrant H3K79 methylation has been shown to be necessary for oncogenic transformation mediated by a number of MLL-fusions. These recent findings have generated tremendous interest in H3K79 methylation as a therapeutic target in the MLL rearranged leukemias. The plant-homeodomain (PHD) and leucine zipper-containing protein AF10 biochemically interacts with DOT1L and is believed to influence H3K79 methylation. We generated conditional knockout mice in which the Dot1l-interacting octapeptide-motif leucine zipper (OM-LZ) domain of Af10 was flanked by LoxP sites. Deletion of the Af10OM-LZ domain with the Cre recombinase is predicted to abrogate the Af10-Dot1l interaction. Deletion of the Af10OM-LZ domain greatly reduced global H3K79 dimethylation as assessed by immunoblotting as well as mass spectrometry in Af10OM-LZ deleted HoxA9/Meis1a transformed cells. Given the importance of H3K79 methylation in MLL-rearranged leukemias, we sought to assess whether the transforming activity of the MLL-AF9 fusion gene was dependent on the Af10-Dot1l interaction. Using an MLL-AF9-IRES-GFP encoding retrovirus, we established immortalized blast-colony forming cultures from mouse lineage negative Sca-1 positive/Kit positive (LSK) bone marrow cells bearing floxed Af10OM-LZ alleles. Deletion of the Af10OM-LZ domain with Cre-recombinase dramatically reduced H3K79me2 on the MLL-target genes Hoxa5-10 and Meis1, leading to downregulation of these transcripts. We performed colony-forming cell (CFC) assays from MLL-AF9 transformed cells in the presence or absence of the Af10OM-LZ allele. In the first week, Af10OM-LZ deletion profoundly impaired the blast-colony forming potential of MLL-AF9 transformed LSKs and the only clones that could serially replate in subsequent passages had escaped Af10OM-LZ excision. Af10OM-LZ deleted colonies were very small and spread-out and showed morphological features of terminal myeloid differentiation. In contrast, HoxA9/Meis1 transformed LSK cells expanded normally in the absence of the Af10OM-LZ domain. These results demonstrate that the Af10OM-LZ, much like Dot1l, is critical for the in vitro transforming activity of the MLL-AF9 fusion gene, but does not non-specifically inhibit cellular proliferation. We then sought to investigate the potential role of the Af10OM-LZ domain in the in vivo leukemogenic activity of MLL-AF9. We generated primary MLL-AF9 leukemias from LSKs harboring floxed Af10OM-LZ alleles. Deletion of the Af10OM-LZ domain in cells explanted from the MLL-AF9 primary leukemias led to a significant increase in the disease latency in secondary recipient mice. Moreover, limiting dilution analysis of MLL-AF9 leukemias with or without the Af10OM-LZ domain demonstrated a >100 fold decrease in the frequency of leukemia initiating cells in the absence of the Af10OM-LZ domain. Microarray analysis showed that a vast majority of MLL-AF9 target genes were significantly downregulated in Af10OM-LZ deleted as compared to Af10OM-LZ wildtype MLL-AF9 leukemias. However, the Af10OM-LZ deleted cells could still eventually cause leukemia. This is intriguing given that Af10OM-LZ deletion, similar to Dot1l deletion, leads to a significant reduction in H3K79 dimethylation as well as MLL-target gene expression. A more detailed analysis of H3K79 methylation using mass spectrometry revealed that in contrast to H3K79 dimethylation, global levels of H3K79 mono-methylation were largely unchanged in Af10OM-LZ deleted cells. This suggests the residual MLL-AF9 target gene expression seen in Af10OM-LZ deleted cells is maintained by H3K79 monomethylation. Our results demonstrate a surprising role for Af10 in the conversion of H3K79 monomethylation to dimethylation and reveal the AF10-DOT1L interaction as an attractive therapeutic target in MLL-rearranged leukemias. Disclosures: Armstrong: Epizyme: Consultancy.

scholarly journals E2f1, E2f2, and E2f3 Control E2F Target Expression and Cellular Proliferation via a p53-Dependent Negative Feedback Loop

2007 ◽  
Vol 27 (1) ◽  
pp. 65-78 ◽  
Author(s):  
Cynthia Timmers ◽  
Nidhi Sharma ◽  
Rene Opavsky ◽  
Baidehi Maiti ◽  
Lizhao Wu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Target Gene ◽  
Target Genes ◽  
Cellular Proliferation ◽  
Kinase Activity ◽  
Cyclin Dependent Kinase ◽  
Control Of Gene Expression ◽  
Target Gene Expression ◽  
Rb Phosphorylation ◽  
P53 Target Genes

ABSTRACT E2F-mediated control of gene expression is believed to have an essential role in the control of cellular proliferation. Using a conditional gene-targeting approach, we show that the targeted disruption of the entire E2F activator subclass composed of E2f1, E2f2, and E2f3 in mouse embryonic fibroblasts leads to the activation of p53 and the induction of p53 target genes, including p21 CIP1 . Consequently, cyclin-dependent kinase activity and retinoblastoma (Rb) phosphorylation are dramatically inhibited, leading to Rb/E2F-mediated repression of E2F target gene expression and a severe block in cellular proliferation. Inactivation of p53 in E2f1-, E2f2-, and E2f3-deficient cells, either by spontaneous mutation or by conditional gene ablation, prevented the induction of p21 CIP1 and many other p53 target genes. As a result, cyclin-dependent kinase activity, Rb phosphorylation, and E2F target gene expression were restored to nearly normal levels, rendering cells responsive to normal growth signals. These findings suggest that a critical function of the E2F1, E2F2, and E2F3 activators is in the control of a p53-dependent axis that indirectly regulates E2F-mediated transcriptional repression and cellular proliferation.

scholarly journals Notch Activation Is an Early and Critical Event during T-Cell Leukemogenesis in Ikaros-Deficient Mice

2006 ◽  
Vol 26 (1) ◽  
pp. 209-220 ◽  
Author(s):  
Alexis Dumortier ◽  
Robin Jeannet ◽  
Peggy Kirstetter ◽  
Eva Kleinmann ◽  
MacLean Sellars ◽  
...  
Keyword(s):  
Gene Expression ◽  
Tumor Suppressor ◽  
Target Gene ◽  
Critical Role ◽  
Ectopic Expression ◽  
Notch Pathway ◽  
Notch Target Gene ◽  
Target Gene Expression ◽  
T Cell Leukemogenesis ◽  
Notch Activation

ABSTRACT The Ikaros transcription factor is both a key regulator of lymphocyte differentiation and a tumor suppressor in T lymphocytes. Mice carrying a hypomorphic mutation (IkL/L) in the Ikaros gene all develop thymic lymphomas. IkL/L tumors always exhibit strong activation of the Notch pathway, which is required for tumor cell proliferation in vitro. Notch activation occurs early in tumorigenesis and may precede transformation, as ectopic expression of the Notch targets Hes-1 and Deltex-1 is detected in thymocytes from young IkL/L mice with no overt signs of transformation. Notch activation is further amplified by secondary mutations that lead to C-terminal truncations of Notch 1. Strikingly, restoration of Ikaros activity in tumor cells leads to a rapid and specific downregulation of Notch target gene expression and proliferation arrest. Furthermore, Ikaros binds to the Notch-responsive element in the Hes-1 promoter and represses Notch-dependent transcription from this promoter. Thus, Ikaros-mediated repression of Notch target gene expression may play a critical role in defining the tumor suppressor function of this factor.

scholarly journals SAT-726 Estrogen Receptor Alpha as a Potential Target for Bisphenol A-Mediated Epigenetic Reprogramming: An in Vitro Analysis

2020 ◽  
Vol 4 (Supplement_1) ◽  
Author(s):  
Morgan Gallo ◽  
Lindsey S Treviño ◽  
Tiffany A Katz
Keyword(s):  
Gene Expression ◽  
Target Gene ◽  
Target Genes ◽  
Hepatic Cell ◽  
Time Points ◽  
Target Gene Expression ◽  
Er Alpha ◽  
Hepatic Cell Lines ◽  
Gene Expression Levels

Abstract Perinatal exposure to bisphenol A (BPA) has been shown to reprogram the hepatic epigenome of rodents and may promote the development of various metabolic diseases later in life, such as nonalcoholic fatty liver disease (NAFLD). This developmental reprogramming is characterized by the creation of “super promoters” at target genes implicated in metabolic pathways. While it is unclear how these “super promoters” are created, their creation is potentially mediated through BPA and estrogen receptor (ER) interaction. In order to test this potential mechanism, in vitro methods were used to examine ER target gene expression via RT-qPCR in 2 human hepatic cell lines transiently transfected with the ER isoform, ER alpha, prior to BPA exposure for various lengths of time. Within individual time points, there were no significant differences in target gene expression levels between cells that had been transfected with ER alpha and the vector control. Gene expression levels in the target genes were visibly increased at the 24-hour exposure mark in both transfection groups in comparison to the 0- and 6-hour time points, however only a fraction of these increases were found to be statistically significant. These gene expression patterns are not only consistent with previous studies examining target gene expression in BPA-treated hepatic cell lines, but more importantly, suggest BPA does not act via ER alpha to orchestrate the epigenetic changes seen in vitro. BPA may interact with a different ER isoform or an unknown target to create the observed “super promoters” at target genes, reinforcing the promiscuity of BPA and other xenoestrogens in facilitating epigenetic modifications, and ultimately, disease phenotypes.

FLT3ITD Target Enhancers Are Primed but Inaccessible in Fetal Hematopoietic Progenitors

Blood ◽  
2019 ◽  
Vol 134 (Supplement_1) ◽  
pp. 1228-1228
Author(s):  
Yanan Li ◽  
Riddhi M Patel ◽  
Emily Casey ◽  
Jeffrey A. Magee
Keyword(s):  
Gene Expression ◽  
Transcription Factors ◽  
Target Gene ◽  
Target Genes ◽  
Conflicts Of Interest ◽  
Gene Activation ◽  
Chromatin Accessibility ◽  
Luciferase Reporter ◽  
Enhancer Activity ◽  
Target Gene Expression

The FLT3 Internal Tandem Duplication (FLT3ITD) is common somatic mutation in acute myeloid leukemia (AML). We have previously shown that FLT3ITD fails to induce changes in HSC self-renewal, myelopoiesis and leukemogenesis during fetal stages of life. FLT3ITD signal transduction pathways are hyperactivated in fetal progenitors, but FLT3ITD target genes are not. This suggests that postnatal-specific transcription factors may be required to help induce FLT3ITD target gene expression. Alternatively, repressive histone modifications may impose a barrier to FLT3ITD target gene activation in fetal HPCs that is relaxed during postnatal development. To resolve these possibilities, we used ATAC-seq, as well as H3K4me1, H3K27ac and H3K27me3 ChIP-seq, to identify cis-elements that putatively control FLT3ITD target gene expression in fetal and adult hematopoietic progenitor cells (HPCs). We identified many enhancer elements (ATAC-seq peaks with H3K4me1 and H3K27ac) that exhibited increased chromatin accessibility and activity in FLT3ITD adult HPCs relative to wild type adult HPCs. These elements were enriched near FLT3ITD target genes. HOMER analysis showed enrichment for STAT5, ETS, RUNX1 and IRF binding motifs within the FLT3ITD target enhancers, but motifs for temporally dynamic transcription factors were not identified. We cloned a subset of the enhancers and confirmed that they could synergize with their promoter to activate a luciferase reporter. For representative enhancers, STAT5 binding sites were required to activate the enhancer - as anticipated - and RUNX1 repressed enhancer activity. We tested whether accessibility or priming changed between fetal and adult stages of HPC development. FLT3ITD-dependent changes in chromatin accessibility were not observed in fetal HPCs, though the enhancers were primed early in development as evidenced by the presence of H3K4me1. Repressive H3K27me3 were not present at FLT3ITD target enhancers in either or adult HPCs. The data show that FLT3ITD target enhancers are demarcated early in hematopoietic development, long before they become responsive to FLT3ITD signaling. Repressive marks do not appear to create an epigenetic barrier to enhancer activation in the fetal stage. Instead, age-specific transcription factors are likely required to pioneer enhancer elements so that they can respond to STAT5 and other FLT3ITD effectors. Disclosures No relevant conflicts of interest to declare.

scholarly journals Identification and Evaluation of Reference Genes for Normalization of Gene Expression in Developmental Stages, Sexes, and Tissues of Diaphania caesalis (Lepidoptera, Pyralidae)

2020 ◽  
Vol 20 (1) ◽  
Author(s):  
Zheng Wang ◽  
Qianqian Meng ◽  
Xi Zhu ◽  
Shiwei Sun ◽  
Aiqin Liu ◽  
...  
Keyword(s):  
Gene Expression ◽  
Reference Genes ◽  
Target Gene ◽  
Target Genes ◽  
Developmental Stages ◽  
Expression Profiles ◽  
Transcriptional Level ◽  
Internal Reference ◽  
Target Gene Expression ◽  
Qrt Pcr

Abstract Diaphania caesalis (Walker) is an important boring insect mainly distributed in subtropical and tropical areas and attacked tropical woody grain crops, such as starchy plants of Artocarpus. Quantitative real-time polymerase chain reaction (qRT-PCR) is a powerful approach for investigating target genes expression profiles at the transcriptional level. However, the identification and selection of internal reference genes, which is often overlooked, is the most vital step before the analysis of target gene expression by qRT-PCR. So far, the reliable internal reference genes under a certain condition of D. caesalis have not been investigated. Therefore, this study evaluated the expression stability of eight candidate reference genes including ACT, β-TUB, GAPDH, G6PDH, RPS3a, RPL13a, EF1α, and EIF4A in different developmental stages, tissues and sexes using geNorm, NormFinder and BestKeeper algorithms. To verify the stability of the recommended internal reference genes, the expression levels of DcaeOBP5 were analyzed under different treatment conditions. The results indicated that ACT, RPL13a, β-TUB, RPS3a, and EF1α were identified as the most stable reference genes for further studies on target gene expression involving different developmental stages of D. caesalis. And ACT and EIF4A were recommended as stable reference genes for different tissues. Furthermore, ACT, EF1α, and RPS3a were ranked as the best reference genes in different sexes based on three algorithms. Our research represents the critical first step to normalize qRT-PCR data and ensure the accuracy of expression of target genes involved in phylogenetic and physiological mechanism at the transcriptional level in D. caesalia.

scholarly journals Analysis of WT1 target gene expression in stably transfected cell lines

Oncogene ◽  
1998 ◽  
Vol 17 (10) ◽  
pp. 1287-1294 ◽  
Author(s):  
Claudia Thäte ◽  
Christoph Englert ◽  
Manfred Gessler
Keyword(s):  
Gene Expression ◽  
Cell Lines ◽  
Target Gene ◽  
Target Gene Expression
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