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Cabezas-Cruz A, Alberdi P, Ayllón N, Valdés JJ, Pierce R, Villar M, de la Fuente J. Anaplasma phagocytophilum increases the levels of histone modifying enzymes to inhibit cell apoptosis and facilitate pathogen infection in the tick vector Ixodes scapularis. Epigenetics 2016; 11:303-19. [PMID: 27019326 DOI: 10.1080/15592294.2016.1163460] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
Epigenetic mechanisms have not been characterized in ticks despite their importance as vectors of human and animal diseases worldwide. The objective of this study was to characterize the histones and histone modifying enzymes (HMEs) of the tick vector Ixodes scapularis and their role during Anaplasma phagocytophilum infection. We first identified 5 histones and 34 HMEs in I. scapularis in comparison with similar proteins in model organisms. Then, we used transcriptomic and proteomic data to analyze the mRNA and protein levels of I. scapularis histones and HMEs in response to A. phagocytophilum infection of tick tissues and cultured cells. Finally, selected HMEs were functionally characterized by pharmacological studies in cultured tick cells. The results suggest that A. phagocytophilum manipulates tick cell epigenetics to increase I. scapularis p300/CBP, histone deacetylase, and Sirtuin levels, resulting in an inhibition of cell apoptosis that in turn facilitates pathogen infection and multiplication. These results also suggest that a compensatory mechanism might exist by which A. phagocytophilum manipulates tick HMEs to regulate transcription and apoptosis in a tissue-specific manner to facilitate infection, but preserving tick fitness to guarantee survival of both pathogens and ticks. Our study also indicates that the pathogen manipulates arthropod and vertebrate cell epigenetics in similar ways to inhibit the host response to infection. Epigenetic regulation of tick biological processes is an essential element of the infection by A. phagocytophilum and the study of the mechanisms and principal actors involved is likely to provide clues for the development of anti-tick drugs and vaccines.
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Affiliation(s)
- Alejandro Cabezas-Cruz
- a University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center d'Infection et d'Immunité de Lille , Lille , France
| | - Pilar Alberdi
- b SaBio. Instituto de Investigación de Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM , Ciudad Real , Spain
| | - Nieves Ayllón
- b SaBio. Instituto de Investigación de Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM , Ciudad Real , Spain
| | - James J Valdés
- c Institute of Parasitology, Biology Center of the Academy of Sciences of the Czech Republic , Branisovska 31, Budweis, České Budějovice , Czech Republic.,d Department of Virology , Veterinary Research Institute , Hudcova 70, Brno , Czech Republic
| | - Raymond Pierce
- a University Lille, CNRS, Inserm, CHU Lille, Institut Pasteur de Lille, U1019 - UMR 8204 - CIIL - Center d'Infection et d'Immunité de Lille , Lille , France
| | - Margarita Villar
- b SaBio. Instituto de Investigación de Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM , Ciudad Real , Spain
| | - José de la Fuente
- b SaBio. Instituto de Investigación de Recursos Cinegéticos, IREC-CSIC-UCLM-JCCM , Ciudad Real , Spain.,e Department of Veterinary Pathobiology , Center for Veterinary Health Sciences, Oklahoma State University , Stillwater , OK , USA
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202
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HBx-upregulated lncRNA UCA1 promotes cell growth and tumorigenesis by recruiting EZH2 and repressing p27Kip1/CDK2 signaling. Sci Rep 2016; 6:23521. [PMID: 27009634 PMCID: PMC4806364 DOI: 10.1038/srep23521] [Citation(s) in RCA: 115] [Impact Index Per Article: 14.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 03/09/2016] [Indexed: 12/11/2022] Open
Abstract
It is well accepted that HBx plays the major role in hepatocarcinogenesis associated with hepatitis B virus (HBV) infections. However, little was known about its role in regulating long noncoding RNAs (lncRNAs), a large group of transcripts regulating a variety of biological processes including carcinogenesis in mammalian cells. Here we report that HBx upregulates UCA1 genes and downregulates p27 genes in hepatic LO2 cells. Further studies show that the upregulated UCA1 promotes cell growth by facilitating G1/S transition through CDK2 in both hepatic and hepatoma cells. Knock down of UCA1 in HBx-expressing hepatic and hepatoma cells resulted in markedly increased apoptotic cells by elevating the cleaved caspase-3 and caspase-8. More importantly, UCA1 is found to be physically associated with enhancer of zeste homolog 2 (EZH2), which suppresses p27Kip1 through histone methylation (H3K27me3) on p27Kip1 promoter. We also show that knockdown of UCA1 in hepatoma cells inhibits tumorigenesis in nude mice. In a clinic study, UCA1 is found to be frequently up-regulated in HBx positive group tissues in comparison with the HBx negative group, and exhibits an inverse correlation between UCA1 and p27Kip1 levels. Our findings demonstrate an important mechanism of hepatocarcinogenesis through the signaling of HBx-UCA1/EZH2-p27Kip1 axis, and a potential target of HCC.
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203
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Bao L, Alexander JB, Zhang H, Shen K, Chan LS. Interleukin-4 Downregulation of Involucrin Expression in Human Epidermal Keratinocytes Involves Stat6 Sequestration of the Coactivator CREB-Binding Protein. J Interferon Cytokine Res 2016; 36:374-81. [PMID: 26918372 DOI: 10.1089/jir.2015.0056] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Skin barrier defects play an important role in atopic dermatitis (AD). Involucrin, an important barrier protein suppressed in human AD, is downregulated by interleukin-4 (IL-4). However, the molecular mechanism for IL-4 downregulation of involucrin has not been delineated, and especially how Stat6, a transcriptional activator, represses involucrin expression is unknown. Since Stats usually recruit p300/CBP in the general transcription machinery of their target genes and involucrin expression also involves p300/CBP, we hypothesize that Stat6 activated by IL-4 may sequestrate p300/CBP from the involucrin transcription complex, thus suppressing involucrin expression in keratinocytes. Using IL-4 transgenic mice, an AD mouse model, we find that involucrin expression is similarly downregulated as in human AD. In HaCat cells, the Jak inhibitor and dominant negative studies indicate that the Jaks-Stat6 pathway is involved in IL-4 downregulation of involucrin. Next, we transfected HaCat cells with an involucrin promoter-luciferase construct and then treated them with IL-4. IL-4 greatly suppresses the promoter activity, which is totally abolished by cotransfecting the CREB-binding protein (CBP) expression vector, indicating that IL-4 cannot downregulate involucrin in the presence of excess CBP. Finally, chromatin immunoprecipitation assay demonstrates that IL-4 decreases CBP binding to the involucrin transcription complex. For the first time, we defined a molecular mechanism for IL-4 downregulation of involucrin in keratinocytes, which may play an important role in the pathogenesis of AD.
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Affiliation(s)
- Lei Bao
- 1 Department of Dermatology, University of Illinois at Chicago , Chicago, Illinois
| | - Jaime B Alexander
- 1 Department of Dermatology, University of Illinois at Chicago , Chicago, Illinois
| | - Huayi Zhang
- 1 Department of Dermatology, University of Illinois at Chicago , Chicago, Illinois
| | - Kui Shen
- 1 Department of Dermatology, University of Illinois at Chicago , Chicago, Illinois
| | - Lawrence S Chan
- 1 Department of Dermatology, University of Illinois at Chicago , Chicago, Illinois.,2 Department of Microbiology & Immunology, University of Illinois at Chicago , Chicago, Illinois.,3 Medical Service, Jesse Brown VA Med Center , Chicago, Illinois
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204
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Becker M, Guadalupe T, Franke B, Hibar DP, Renteria ME, Stein JL, Thompson PM, Francks C, Vernes SC, Fisher SE. Early developmental gene enhancers affect subcortical volumes in the adult human brain. Hum Brain Mapp 2016; 37:1788-800. [PMID: 26890892 DOI: 10.1002/hbm.23136] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2015] [Revised: 12/30/2015] [Accepted: 01/26/2016] [Indexed: 11/08/2022] Open
Abstract
Genome-wide association screens aim to identify common genetic variants contributing to the phenotypic variability of complex traits, such as human height or brain morphology. The identified genetic variants are mostly within noncoding genomic regions and the biology of the genotype-phenotype association typically remains unclear. In this article, we propose a complementary targeted strategy to reveal the genetic underpinnings of variability in subcortical brain volumes, by specifically selecting genomic loci that are experimentally validated forebrain enhancers, active in early embryonic development. We hypothesized that genetic variation within these enhancers may affect the development and ultimately the structure of subcortical brain regions in adults. We tested whether variants in forebrain enhancer regions showed an overall enrichment of association with volumetric variation in subcortical structures of >13,000 healthy adults. We observed significant enrichment of genomic loci that affect the volume of the hippocampus within forebrain enhancers (empirical P = 0.0015), a finding which robustly passed the adjusted threshold for testing of multiple brain phenotypes (cutoff of P < 0.0083 at an alpha of 0.05). In analyses of individual single nucleotide polymorphisms (SNPs), we identified an association upstream of the ID2 gene with rs7588305 and variation in hippocampal volume. This SNP-based association survived multiple-testing correction for the number of SNPs analyzed but not for the number of subcortical structures. Targeting known regulatory regions offers a way to understand the underlying biology that connects genotypes to phenotypes, particularly in the context of neuroimaging genetics. This biology-driven approach generates testable hypotheses regarding the functional biology of identified associations. Hum Brain Mapp 37:1788-1800, 2016. © 2016 Wiley Periodicals, Inc.
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Affiliation(s)
- Martin Becker
- Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands
| | - Tulio Guadalupe
- Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands
| | - Barbara Franke
- Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands.,Department of Human Genetics, Radboud University Medical Center, Nijmegen, the Netherlands.,Department of Psychiatry, Radboud University Medical Center, Nijmegen, the Netherlands
| | - Derrek P Hibar
- Imaging Genetics Center, Keck School of Medicine, University of Southern California, Marina Del Rey, California
| | - Miguel E Renteria
- Genetic Epidemiology, QIMR Berghofer Medical Research Institute, Brisbane, Queensland, Australia
| | - Jason L Stein
- Imaging Genetics Center, Keck School of Medicine, University of Southern California, Marina Del Rey, California.,Department of Neurology, Neurogenetics Program, UCLA School of Medicine, Los Angeles, California
| | - Paul M Thompson
- Imaging Genetics Center, Keck School of Medicine, University of Southern California, Marina Del Rey, California
| | - Clyde Francks
- Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - Sonja C Vernes
- Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - Simon E Fisher
- Max Planck Institute for Psycholinguistics, Nijmegen, the Netherlands.,Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
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205
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Constitutive NF-κB activation in AML: Causes and treatment strategies. Crit Rev Oncol Hematol 2016; 98:35-44. [DOI: 10.1016/j.critrevonc.2015.10.001] [Citation(s) in RCA: 44] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2015] [Revised: 08/12/2015] [Accepted: 10/01/2015] [Indexed: 01/01/2023] Open
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206
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Polycomb inhibits histone acetylation by CBP by binding directly to its catalytic domain. Proc Natl Acad Sci U S A 2016; 113:E744-53. [PMID: 26802126 DOI: 10.1073/pnas.1515465113] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022] Open
Abstract
Drosophila Polycomb (PC), a subunit of Polycomb repressive complex 1 (PRC1), is well known for its role in maintaining repression of the homeotic genes and many others and for its binding to trimethylated histone H3 on Lys 27 (H3K27me3) via its chromodomain. Here, we identify a novel activity of PC: inhibition of the histone acetylation activity of CREB-binding protein (CBP). We show that PC and its mammalian CBX orthologs interact directly with the histone acetyltransferase (HAT) domain of CBP, binding to the previously identified autoregulatory loop, whose autoacetylation greatly enhances HAT activity. We identify a conserved PC motif adjacent to the chromodomain required for CBP binding and show that PC binding inhibits acetylation of histone H3. CBP autoacetylation impairs PC binding in vitro, and PC is preferentially associated with unacetylated CBP in vivo. PC knockdown elevates the acetylated H3K27 (H3K27ac) level globally and at promoter regions of some genes that are bound by both PC and CBP. Conversely, PC overexpression decreases the H3K27ac level in vivo and also suppresses CBP-dependent Polycomb phenotypes caused by overexpression of Trithorax, an antagonist of Polycomb silencing. We find that PC is physically associated with the initiating form of RNA polymerase II (Pol II) and that many promoters co-occupied by PC and CBP are associated with paused Pol II, suggesting that PC may play a role in Pol II pausing. These results suggest that PC/PRC1 inhibition of CBP HAT activity plays a role in regulating transcription of both repressed and active PC-regulated genes.
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207
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Kaypee S, Sudarshan D, Shanmugam MK, Mukherjee D, Sethi G, Kundu TK. Aberrant lysine acetylation in tumorigenesis: Implications in the development of therapeutics. Pharmacol Ther 2016; 162:98-119. [PMID: 26808162 DOI: 10.1016/j.pharmthera.2016.01.011] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
Abstract
The 'language' of covalent histone modifications translates environmental and cellular cues into gene expression. This vast array of post-translational modifications on histones are more than just covalent moieties added onto a protein, as they also form a platform on which crucial cellular signals are relayed. The reversible lysine acetylation has emerged as an important post-translational modification of both histone and non-histone proteins, dictating numerous epigenetic programs within a cell. Thus, understanding the complex biology of lysine acetylation and its regulators is essential for the development of epigenetic therapeutics. In this review, we will attempt to address the complexities of lysine acetylation in the context of tumorigenesis, their role in cancer progression and emphasize on the modalities developed to target lysine acetyltransferases towards cancer treatment.
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Affiliation(s)
- Stephanie Kaypee
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, Karnataka, India
| | - Deepthi Sudarshan
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, Karnataka, India
| | - Muthu K Shanmugam
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 117600, Singapore
| | - Debanjan Mukherjee
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, Karnataka, India
| | - Gautam Sethi
- Department of Pharmacology, Yong Loo Lin School of Medicine, National University of Singapore, 117600, Singapore
| | - Tapas K Kundu
- Transcription and Disease Laboratory, Molecular Biology and Genetics Unit, Jawaharlal Nehru Centre for Advanced Scientific Research, Bangalore, Karnataka, India.
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208
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Up-Regulation of Human Inducible Nitric Oxide Synthase by p300 Transcriptional Complex. PLoS One 2016; 11:e0146640. [PMID: 26751080 PMCID: PMC4713468 DOI: 10.1371/journal.pone.0146640] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/04/2015] [Accepted: 12/21/2015] [Indexed: 11/19/2022] Open
Abstract
p300, a ubiquitous transcription coactivator, plays an important role in gene activation. Our previous work demonstrated that human inducible nitric oxide synthase (hiNOS) expression can be highly induced with the cytokine mixture (CM) of TNF-α + IL-1β + IFN-γ. In this study, we investigated the functional role of p300 in the regulation of hiNOS gene expression. Our initial data showed that overexpression of p300 significantly increased the basal and cytokine-induced hiNOS promoter activities in A549 cells. Interestingly, p300 activated cytokine-induced hiNOS transcriptional activity was completely abrogated by deleting the upstream hiNOS enhancer at -5 kb to -6 kb in the promoter. Furthermore, p300 over-expression increased cytokine-induced transcriptional activity on a heterologous minimal TK promoter with the same hiNOS enhancer. Site-directed mutagenesis of the hiNOS AP-1 motifs revealed that an intact upstream (-5.3kb) AP-1 binding site was critical for p300 mediated cytokine-induced hiNOS transcription. Furthermore, our ChIP analysis demonstrated that p300 was binding to Jun D and Fra-2 proteins at -5.3 kb AP-1 binding site in vivo. Lastly, our 3C assay was able to detect a long DNA loop between the hiNOS enhancer and core promoter site, and ChIP loop assay confirmed that p300 binds to AP-1 and RNA pol II proteins. Overall, our results suggest that coactivator p300 mediates cytokine-induced hiNOS transactivation by forming a distant DNA loop between its enhancer and core promoter region.
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209
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LaBarge SA, Migdal CW, Buckner EH, Okuno H, Gertsman I, Stocks B, Barshop BA, Nalbandian SR, Philp A, McCurdy CE, Schenk S. p300 is not required for metabolic adaptation to endurance exercise training. FASEB J 2015; 30:1623-33. [PMID: 26712218 DOI: 10.1096/fj.15-281741] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2015] [Accepted: 12/11/2015] [Indexed: 11/11/2022]
Abstract
The acetyltransferase, E1a-binding protein (p300), is proposed to regulate various aspects of skeletal muscle development, metabolism, and mitochondrial function,viaits interaction with numerous transcriptional regulators and other proteins. Remarkably, however, the contribution of p300 to skeletal muscle function and metabolism,in vivo, is poorly understood. To address this, we used Cre-LoxP methodology to generate mice with skeletal muscle-specific knockout of E1a-binding protein (mKO). mKO mice were indistinguishable from their wild-type/floxed littermates, with no differences in lean mass, skeletal muscle structure, fiber type, respirometry flux, or metabolites of fatty acid and amino acid metabolism.Ex vivomuscle function in extensor digitorum longus and soleus muscles, including peak stress and time to fatigue, as well asin vivorunning capacity were also comparable. Moreover, expected adaptations to a 20 d voluntary wheel running regime were not compromised in mKO mice. Taken together, these findings demonstrate that p300 is not required for the normal development or functioning of adult skeletal muscle, nor is it required for endurance exercise-mediated mitochondrial adaptations.-LaBarge, S. A., Migdal, C. W., Buckner, E. H., Okuno, H., Gertsman, I., Stocks, B., Barshop, B. A., Nalbandian, S. R., Philp, A., McCurdy, C. E., Schenk, S. p300 is not required for metabolic adaptation to endurance exercise training.
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Affiliation(s)
- Samuel A LaBarge
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Christopher W Migdal
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Elisa H Buckner
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Hiroshi Okuno
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Ilya Gertsman
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Ben Stocks
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Bruce A Barshop
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Sarah R Nalbandian
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Andrew Philp
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Carrie E McCurdy
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
| | - Simon Schenk
- *Department of Orthopaedic Surgery and Department of Pediatrics, School of Medicine, University of California, San Diego, La Jolla, California, USA; School of Sport, Exercise, and Rehabilitation Sciences, University of Birmingham, Edgbaston, United Kingdom; and Department of Human Physiology, University of Oregon, Eugene, Oregon, USA
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210
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Huseby NE, Ravuri C, Moens U. The proteasome inhibitor lactacystin enhances GSH synthesis capacity by increased expression of antioxidant components in an Nrf2-independent, but p38 MAPK-dependent manner in rat colorectal carcinoma cells. Free Radic Res 2015; 50:1-13. [PMID: 26530909 DOI: 10.3109/10715762.2015.1100730] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022]
Abstract
Proteasome inhibitors may induce ER stress and oxidative stress, disrupt signaling pathways, and trigger apoptosis in several cancer cells. However, they are also reported to increase glutathione (GSH) synthesis and protect cells from oxidative stress. In the present study, we showed that the proteasome inhibitor lactacystin increased reactive oxygen species (ROS) and GSH levels after the treatment of HT-29 colorectal cancer cells. The increased GSH depended upon the activity of glutamate cysteine ligase (GCL), uptake of cystine/cysteine via the cystine/glutamate transporter [Formula: see text], and the activity of γ-glutamyltransferase (GGT). Increased transcription levels of the catalytic subunit of glutamate cysteine ligase (GCLC), the catalytic subunit xCT of [Formula: see text], and GGT were induced by lactacystin, although with different kinetics and stoichiometry. Lactacystin treatment also augmented protein levels of GCLC, xCT, and GGT, but significant levels were not detected until 48 h after initiation of lactacystin treatment. These increases in protein levels were dependent on the p38 MAPK pathway. Studies in cells transfected with siRNA against the transcription factor Nrf2 demonstrated that the promoter activities of xCT and GCLC, but not of GGT, depended on Nrf2. However, depletion of Nrf2 had no effect on lactacystin-induced upregulation of the GGT, GCLC, and xCT mRNA levels. Taken together, our results suggest that oxidative stress provoked by proteasomal inhibition results in the elevation of cellular GSH levels due to increased synthesis of GSH and uptake of cystine/cysteine. Following treatment with lactacystin, enhanced expression of antioxidant components involved in GSH homeostasis is p38 MAPK-dependent, but Nrf2-independent, resulting in increased GSH synthesis capacity.
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Affiliation(s)
- Nils-Erik Huseby
- a Tumor Biology Research Group, Department of Medical Biology, Faculty of Health Sciences , University of Tromsø , Tromsø , Norway
| | - Chandra Ravuri
- a Tumor Biology Research Group, Department of Medical Biology, Faculty of Health Sciences , University of Tromsø , Tromsø , Norway
| | - Ugo Moens
- b Molecular Inflammation Research Group, Department of Medical Biology, Faculty of Health Sciences , University of Tromsø , Tromsø , Norway
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211
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Negri G, Magini P, Milani D, Colapietro P, Rusconi D, Scarano E, Bonati MT, Priolo M, Crippa M, Mazzanti L, Wischmeijer A, Tamburrino F, Pippucci T, Finelli P, Larizza L, Gervasini C. From Whole Gene Deletion to Point Mutations of EP300-Positive Rubinstein-Taybi Patients: New Insights into the Mutational Spectrum and Peculiar Clinical Hallmarks. Hum Mutat 2015; 37:175-83. [PMID: 26486927 DOI: 10.1002/humu.22922] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2015] [Accepted: 10/12/2015] [Indexed: 12/16/2022]
Abstract
Rubinstein-Taybi syndrome (RSTS) is a rare congenital neurodevelopmental disorder characterized by growth deficiency, skeletal abnormalities, dysmorphic features, and intellectual disability. Causative mutations in CREBBP and EP300 genes have been identified in ∼55% and ∼8% of affected individuals. To date, only 28 EP300 alterations in 29 RSTS clinically described patients have been reported. EP300 analysis of 22 CREBBP-negative RSTS patients from our cohort led us to identify six novel mutations: a 376-kb deletion depleting EP300 gene; an exons 17-19 deletion (c.(3141+1_3142-1)_(3590+1_3591-1)del/p.(Ile1047Serfs*30)); two stop mutations, (c.3829A>T/p.(Lys1277*) and c.4585C>T/p.(Arg1529*)); a splicing mutation (c.1878-12A>G/p.(Ala627Glnfs*11)), and a duplication (c.4640dupA/p.(Asn1547Lysfs*3)). All EP300-mutated individuals show a mild RSTS phenotype and peculiar findings including maternal gestosis, skin manifestation, especially nevi or keloids, back malformations, and a behavior predisposing to anxiety. Furthermore, the patient carrying the complete EP300 deletion does not show a markedly severe clinical picture, even if a more composite phenotype was noticed. By characterizing six novel EP300-mutated patients, this study provides further insights into the EP300-specific clinical presentation and expands the mutational repertoire including the first case of a whole gene deletion. These new data will enhance EP300-mutated cases identification highlighting distinctive features and will improve the clinical practice allowing a better genotype-phenotype correlation.
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Affiliation(s)
- Gloria Negri
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia
| | - Pamela Magini
- Laboratorio di Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche, Policlinico Ospedaliero Universitario S. Orsola-Malpighi, Bologna, Italia
| | - Donatella Milani
- Unità di Pediatria ad alta Intensità di Cura, Fondazione IRCCS Ca' Granda, Milano, Italia
| | - Patrizia Colapietro
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia
| | - Daniela Rusconi
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia
| | - Emanuela Scarano
- UO di Endocrinologia Pediatrica e Malattie Rare, Dipartimento di Pediatria, Ospedale Universitario S. Orsola Malpighi, Università degli Studi di Bologna, Bologna, Italia
| | - Maria Teresa Bonati
- Clinica di Genetica Medica, IRCCS Istituto Auxologico Italiano, Milano, Italia
| | - Manuela Priolo
- UOC Genetica Medica, Azienda Ospedaliera Bianchi-Melacrino-Morelli, Reggio Calabria, Italia
| | - Milena Crippa
- Laboratorio di Citogenetica e Genetica Molecolare, Centro di Ricerche e Tecnologie Biomediche, IRCCS Istituto Auxologico Italiano, Milano, Italia
| | - Laura Mazzanti
- UO di Endocrinologia Pediatrica e Malattie Rare, Dipartimento di Pediatria, Ospedale Universitario S. Orsola Malpighi, Università degli Studi di Bologna, Bologna, Italia
| | - Anita Wischmeijer
- Laboratorio di Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche, Policlinico Ospedaliero Universitario S. Orsola-Malpighi, Bologna, Italia
| | - Federica Tamburrino
- UO di Endocrinologia Pediatrica e Malattie Rare, Dipartimento di Pediatria, Ospedale Universitario S. Orsola Malpighi, Università degli Studi di Bologna, Bologna, Italia
| | - Tommaso Pippucci
- Laboratorio di Genetica Medica, Dipartimento di Scienze Mediche e Chirurgiche, Policlinico Ospedaliero Universitario S. Orsola-Malpighi, Bologna, Italia
| | - Palma Finelli
- Laboratorio di Citogenetica e Genetica Molecolare, Centro di Ricerche e Tecnologie Biomediche, IRCCS Istituto Auxologico Italiano, Milano, Italia.,Dipartimento di Biotecnologie Mediche e Medicina Traslazionale, Università degli Studi di Milano, Milano, Italia
| | - Lidia Larizza
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia.,Laboratorio di Citogenetica e Genetica Molecolare, Centro di Ricerche e Tecnologie Biomediche, IRCCS Istituto Auxologico Italiano, Milano, Italia
| | - Cristina Gervasini
- Genetica Medica, Dipartimento di Scienze della Salute, Università degli Studi di Milano, Milano, Italia
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212
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Chen X, Du Z, Li X, Wang L, Wang F, Shi W, Hao A. Protein Palmitoylation Regulates Neural Stem Cell Differentiation by Modulation of EID1 Activity. Mol Neurobiol 2015; 53:5722-36. [PMID: 26497028 DOI: 10.1007/s12035-015-9481-y] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/22/2015] [Accepted: 10/08/2015] [Indexed: 01/13/2023]
Abstract
The functional significance of palmitoylation in the switch between self-renewal and differentiation of neural stem cells (NSCs) is not well defined, and the underlying mechanisms of protein palmitoylation are not well understood. Here, mouse NSCs were used as a model system and cell behavior was monitored in the presence of the protein palmitoylation inhibitor 2-bromopalmitate (2BRO). Our data show that 2BRO impaired the differentiation of NSCs into both neurons and glia and impaired NSC cell cycle exit. Moreover, the results show that palmitoylation modified E1A-like inhibitor of differentiation one (EID1) and this modification regulated EID1 degradation and CREB-binding protein (CBP)/p300 histone acetyltransferase activity at the switch between self-renewal and differentiation of NSCs. Our results extended the cellular role of palmitoylation, suggesting that it acts as a regulator in the acetylation-dependent gene expression network, and established the epigenetic regulatory function of palmitoylation in the switch between maintenance of multipotency and differentiation in NSCs.
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Affiliation(s)
- Xueran Chen
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China.,Center of Medical Physics and Technology, Hefei Institutes of Physical Science, Chinese Academy of Sciences, No. 350, Shushan Hu Road, Hefei, Anhui, 230031, People's Republic of China
| | - Zhaoxia Du
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Xian Li
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Liyan Wang
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Fuwu Wang
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Wei Shi
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China
| | - Aijun Hao
- Key Laboratory of the Ministry of Education for Experimental Teratology, Shandong Provincial Key Laboratory of Mental Disorders, Department of Histology and Embryology, Shandong University School of Medicine, No. 44, Wenhua Xi Road, Jinan, Shandong, 250012, People's Republic of China.
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213
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Affiliation(s)
- Guangtao Zhang
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai , 1425 Madison Avenue, New York, New York 10029, United States
| | - Steven G Smith
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai , 1425 Madison Avenue, New York, New York 10029, United States
| | - Ming-Ming Zhou
- Department of Structural and Chemical Biology, Icahn School of Medicine at Mount Sinai , 1425 Madison Avenue, New York, New York 10029, United States
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214
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Nakadai T, Fukuda A, Shimada M, Nishimura K, Hisatake K. The RNA binding complexes NF45-NF90 and NF45-NF110 associate dynamically with the c-fos gene and function as transcriptional coactivators. J Biol Chem 2015; 290:26832-45. [PMID: 26381409 DOI: 10.1074/jbc.m115.688317] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2015] [Indexed: 12/13/2022] Open
Abstract
The c-fos gene is rapidly induced to high levels by various extracellular stimuli. We used a defined in vitro transcription system that utilizes the c-fos promoter to purify a coactivator activity in an unbiased manner. We report here that NF45-NF90 and NF45-NF110, which possess archetypical double-stranded RNA binding motifs, have a direct function as transcriptional coactivators. The transcriptional activities of the nuclear factor (NF) complexes (NF45-NF90 and NF45-NF110) are mediated by both the upstream enhancer and core promoter regions of the c-fos gene and do not require their double-stranded RNA binding activities. The NF complexes cooperate with general coactivators, PC4 and Mediator, to elicit a high level of transcription and display multiple interactions with activators and the components of the general transcriptional machinery. Knockdown of the endogenous NF90/NF110 in mouse cells shows an important role for the NF complexes in inducing c-fos transcription. Chromatin immunoprecipitation assays demonstrate that the NF complexes occupy the c-fos enhancer/promoter region before and after serum induction and that their occupancies within the coding region of the c-fos gene increase in parallel to that of RNAPII upon serum induction. In light of their dynamic occupancy on the c-fos gene as well as direct functions in both transcription and posttranscriptional processes, the NF complexes appear to serve as multifunctional coactivators that coordinate different steps of gene expression to facilitate rapid response of inducible genes.
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Affiliation(s)
- Tomoyoshi Nakadai
- From the Department of Molecular Biology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Iruma-gun, Saitama 350-0495, Japan and
| | - Aya Fukuda
- Department of Biochemistry, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Miho Shimada
- From the Department of Molecular Biology, Faculty of Medicine, Saitama Medical University, 38 Morohongo, Moroyama, Iruma-gun, Saitama 350-0495, Japan and
| | - Ken Nishimura
- Department of Biochemistry, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
| | - Koji Hisatake
- Department of Biochemistry, Faculty of Medicine, University of Tsukuba, 1-1-1 Tennodai, Tsukuba, Ibaraki 305-8575, Japan
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215
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Liu YC, Chang PY, Chao CCK. CITED2 silencing sensitizes cancer cells to cisplatin by inhibiting p53 trans-activation and chromatin relaxation on the ERCC1 DNA repair gene. Nucleic Acids Res 2015; 43:10760-81. [PMID: 26384430 PMCID: PMC4678856 DOI: 10.1093/nar/gkv934] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2015] [Accepted: 09/08/2015] [Indexed: 02/07/2023] Open
Abstract
In this study, we show that silencing of CITED2 using small-hairpin RNA (shCITED2) induced DNA damage and reduction of ERCC1 gene expression in HEK293, HeLa and H1299 cells, even in the absence of cisplatin. In contrast, ectopic expression of ERCC1 significantly reduced intrinsic and induced DNA damage levels, and rescued the effects of CITED2 silencing on cell viability. The effects of CITED2 silencing on DNA repair and cell death were associated with p53 activity. Furthermore, CITED2 silencing caused severe elimination of the p300 protein and markers of relaxed chromatin (acetylated H3 and H4, i.e. H3K9Ac and H3K14Ac) in HEK293 cells. Chromatin immunoprecipitation assays further revealed that DNA damage induced binding of p53 along with H3K9Ac or H3K14Ac at the ERCC1 promoter, an effect which was almost entirely abrogated by silencing of CITED2 or p300. Moreover, lentivirus-based CITED2 silencing sensitized HeLa cell line-derived tumor xenografts to cisplatin in immune-deficient mice. These results demonstrate that CITED2/p300 can be recruited by p53 at the promoter of the repair gene ERCC1 in response to cisplatin-induced DNA damage. The CITED2/p300/p53/ERCC1 pathway is thus involved in the cell response to cisplatin and represents a potential target for cancer therapy.
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Affiliation(s)
- Yu-Chin Liu
- Tumor Biology Laboratory, Department of Biochemistry and Molecular Biology, Chang Gung University, 259 Wen-Hua first Road, Gueishan, Taoyuan 333, Taiwan, Republic of China Graduate Institute of Biomedical Sciences, Chang Gung University, 259 Wen-Hua first Road, Gueishan,Taoyuan 333, Taiwan, Republic of China
| | - Pu-Yuan Chang
- Tumor Biology Laboratory, Department of Biochemistry and Molecular Biology, Chang Gung University, 259 Wen-Hua first Road, Gueishan, Taoyuan 333, Taiwan, Republic of China
| | - Chuck C-K Chao
- Tumor Biology Laboratory, Department of Biochemistry and Molecular Biology, Chang Gung University, 259 Wen-Hua first Road, Gueishan, Taoyuan 333, Taiwan, Republic of China Graduate Institute of Biomedical Sciences, Chang Gung University, 259 Wen-Hua first Road, Gueishan,Taoyuan 333, Taiwan, Republic of China
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216
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Cutler T, Sarkar A, Moran M, Steffensmeier A, Puli OR, Mancini G, Tare M, Gogia N, Singh A. Drosophila Eye Model to Study Neuroprotective Role of CREB Binding Protein (CBP) in Alzheimer's Disease. PLoS One 2015; 10:e0137691. [PMID: 26367392 PMCID: PMC4569556 DOI: 10.1371/journal.pone.0137691] [Citation(s) in RCA: 41] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2015] [Accepted: 08/19/2015] [Indexed: 01/09/2023] Open
Abstract
BACKGROUND The progressive neurodegenerative disorder Alzheimer's disease (AD) manifests as loss of cognitive functions, and finally leads to death of the affected individual. AD may result from accumulation of amyloid plaques. These amyloid plaques comprising of amyloid-beta 42 (Aβ42) polypeptides results from the improper cleavage of amyloid precursor protein (APP) in the brain. The Aβ42 plaques have been shown to disrupt the normal cellular processes and thereby trigger abnormal signaling which results in the death of neurons. However, the molecular-genetic mechanism(s) responsible for Aβ42 mediated neurodegeneration is yet to be fully understood. METHODOLOGY/PRINCIPAL FINDINGS We have utilized Gal4/UAS system to develop a transgenic fruit fly model for Aβ42 mediated neurodegeneration. Targeted misexpression of human Aβ42 in the differentiating photoreceptor neurons of the developing eye of transgenic fly triggers neurodegeneration. This progressive neurodegenerative phenotype resembles Alzheimer's like neuropathology. We identified a histone acetylase, CREB Binding Protein (CBP), as a genetic modifier of Aβ42 mediated neurodegeneration. Targeted misexpression of CBP along with Aβ42 in the differentiating retina can significantly rescue neurodegeneration. We found that gain-of-function of CBP rescues Aβ42 mediated neurodegeneration by blocking cell death. Misexpression of Aβ42 affects the targeting of axons from retina to the brain but misexpression of full length CBP along with Aβ42 can restore this defect. The CBP protein has multiple domains and is known to interact with many different proteins. Our structure function analysis using truncated constructs lacking one or more domains of CBP protein, in transgenic flies revealed that Bromo, HAT and polyglutamine (BHQ) domains together are required for the neuroprotective function of CBP. This BHQ domain of CBP has not been attributed to promote survival in any other neurodegenerative disorders. CONCLUSIONS/SIGNIFICANCE We have identified CBP as a genetic modifier of Aβ42 mediated neurodegeneration. Furthermore, we have identified BHQ domain of CBP is responsible for its neuroprotective function. These studies may have significant bearing on our understanding of genetic basis of AD.
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Affiliation(s)
- Timothy Cutler
- Premedical Program, University of Dayton, Dayton, Ohio, 45469, United States of America
| | - Ankita Sarkar
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, United States of America
| | - Michael Moran
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, United States of America
| | - Andrew Steffensmeier
- Premedical Program, University of Dayton, Dayton, Ohio, 45469, United States of America
| | - Oorvashi Roy Puli
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, United States of America
| | - Greg Mancini
- Premedical Program, University of Dayton, Dayton, Ohio, 45469, United States of America
| | - Meghana Tare
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, United States of America
| | - Neha Gogia
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, United States of America
| | - Amit Singh
- Premedical Program, University of Dayton, Dayton, Ohio, 45469, United States of America
- Department of Biology, University of Dayton, Dayton, Ohio, 45469, United States of America
- Center for Tissue Regeneration and Engineering at Dayton (TREND), University of Dayton, Dayton, Ohio, 45469, United States of America
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217
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Romanoski CE, Link VM, Heinz S, Glass CK. Exploiting genomics and natural genetic variation to decode macrophage enhancers. Trends Immunol 2015; 36:507-18. [PMID: 26298065 PMCID: PMC4548828 DOI: 10.1016/j.it.2015.07.006] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2015] [Revised: 07/15/2015] [Accepted: 07/17/2015] [Indexed: 12/18/2022]
Abstract
The mammalian genome contains on the order of a million enhancer-like regions that are required to establish the identities and functions of specific cell types. Here, we review recent studies in immune cells that have provided insight into the mechanisms that selectively activate certain enhancers in response to cell lineage and environmental signals. We describe a working model wherein distinct classes of transcription factors define the repertoire of active enhancers in macrophages through collaborative and hierarchical interactions, and discuss important challenges to this model, specifically providing examples from T cells. We conclude by discussing the use of natural genetic variation as a powerful approach for decoding transcription factor combinations that play dominant roles in establishing the enhancer landscapes, and the potential that these insights have for advancing our understanding of the molecular causes of human disease.
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Affiliation(s)
- Casey E Romanoski
- Department of Cellular and Molecular Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0651, USA
| | - Verena M Link
- Department of Cellular and Molecular Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0651, USA; Faculty of Biology, Department II, Ludwig-Maximilians Universität München, Planegg-Martinsried 85152, Germany
| | - Sven Heinz
- Salk Institute for Biological Studies, 10010 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Christopher K Glass
- Department of Cellular and Molecular Medicine, University of California, San Diego, 9500 Gilman Drive, La Jolla, CA 92093-0651, USA.
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218
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MAPK/ERK signaling pathway-induced hyper-O-GlcNAcylation enhances cancer malignancy. Mol Cell Biochem 2015; 410:101-10. [PMID: 26318312 DOI: 10.1007/s11010-015-2542-8] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2015] [Accepted: 08/18/2015] [Indexed: 12/29/2022]
Abstract
Dysregulated MAPK/ERK signaling is implicated in one-third of human tumors and represents an attractive target for the development of anticancer drugs. Similarly, elevated protein O-GlcNAcylation and O-GlcNAc transferase (OGT) are detected in various cancers and serve as attractive novel cancer-specific therapeutic targets. However, the potential connection between them remains unexplored. Here, a positive correlation was found between the activated MAPK/ERK signaling and hyper-O-GlcNAcylation in various cancer types and inhibition of the MAPK/ERK signaling by 10 µM U0126 significantly decreased the expression of OGT and O-GlcNAcylation in H1299, BPH-1 and DU145 cells; then, the pathway analysis of the potential regulators of OGT obtained from the UCSC Genome Browser was done, and ten downstream targets of ERK pathway were uncovered; the following results showed that ELK1, one of the ten targets of ERK pathway, mediated ERK signaling-induced OGT upregulation; finally, the MTT assay and the soft agar assay showed that the inhibition of MAPK/ERK signaling reduced the promotion effect of hyper-O-GlcNAcylation on cancer cell proliferation and anchorage-independent growth. Taken together, our data originally provided evidence for the regulatory mechanism of hyper-O-GlcNAcylation in tumors, which will be helpful for the development of anticancer drugs targeting to hyper-O-GlcNAcylation. This study also provided a new mechanism by which MAPK/ERK signaling-enhanced cancer malignancy. Altogether, the recently discovered oncogenic factor O-GlcNAc was linked to the classical MAPK/ERK signaling which is essential for the maintenance of malignant phenotype of cancers.
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219
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Molecular and Functional Characterization of Bacopa monniera: A Retrospective Review. EVIDENCE-BASED COMPLEMENTARY AND ALTERNATIVE MEDICINE 2015; 2015:945217. [PMID: 26413131 PMCID: PMC4564644 DOI: 10.1155/2015/945217] [Citation(s) in RCA: 25] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2014] [Revised: 03/24/2015] [Accepted: 04/09/2015] [Indexed: 12/21/2022]
Abstract
Over the last 50 years, laboratories around the world analyzed the pharmacological effect of Bacopa monniera extract in different dimensions, especially as a nerve tonic and memory enhancer. Studies in animal model evidenced that Bacopa treatment can attenuate dementia and enhances memory. Further, they demonstrate that Bacopa primarily either acts via antioxidant mechanism (i.e., neuroprotection) or alters different neurotransmitters (serotonin (5-hydroxytryptamine, 5-HT), dopamine (DA), acetylcholine (ACh), γ-aminobutyric acid (GABA)) to execute the pharmacological effect. Among them, 5-HT has been shown to fine tune the neural plasticity, which is a substrate for memory formation. This review focuses on the studies which trace the effect of Bacopa treatment on serotonergic system and 5-HT mediated key molecular changes that are associated with memory formation.
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220
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Ortega-Martínez S. A new perspective on the role of the CREB family of transcription factors in memory consolidation via adult hippocampal neurogenesis. Front Mol Neurosci 2015; 8:46. [PMID: 26379491 PMCID: PMC4549561 DOI: 10.3389/fnmol.2015.00046] [Citation(s) in RCA: 164] [Impact Index Per Article: 18.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2015] [Accepted: 08/11/2015] [Indexed: 12/21/2022] Open
Abstract
Adult neurogenesis is the process by which new neurons are generated in the brains of adults. Since its discovery 50 years ago, adult neurogenesis has been widely studied in the mammalian brain and has provided a new perspective on the pathophysiology of many psychiatric and neurodegenerative disorders, some of which affect memory. In this regard, adult hippocampal neurogenesis (AHN), which occurs in the subgranular zone (SGZ) of the dentate gyrus (DG), has been suggested to play a role in the formation and consolidation of new memories. This process involves many transcription factors, of which cyclic AMP (cAMP)-responsive element-binding protein (CREB) is a well-documented one. In the developing brain, CREB regulates crucial cell stages (e.g., proliferation, differentiation, and survival), and in the adult brain, it participates in neuronal plasticity, learning, and memory. In addition, new evidence supports the hypothesis that CREB may also participate in learning and memory through its involvement in AHN. This review examines the CREB family of transcription factors, including the different members and known signaling pathways. It highlights the role of CREB as a modulator of AHN, which could underlie its function in memory consolidation mechanisms.
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Affiliation(s)
- Sylvia Ortega-Martínez
- Turku Centre for Biotechnology, Åbo Akademi University and University of Turku Turku, Finland
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221
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Lopez-Atalaya JP, Valor LM, Barco A. Epigenetic factors in intellectual disability: the Rubinstein-Taybi syndrome as a paradigm of neurodevelopmental disorder with epigenetic origin. PROGRESS IN MOLECULAR BIOLOGY AND TRANSLATIONAL SCIENCE 2015; 128:139-76. [PMID: 25410544 DOI: 10.1016/b978-0-12-800977-2.00006-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
The number of genetic syndromes associated with intellectual disability that are caused by mutations in genes encoding chromatin-modifying enzymes has sharply risen in the last decade. We discuss here a neurodevelopmental disorder, the Rubinstein-Taybi syndrome (RSTS), originated by mutations in the genes encoding the lysine acetyltransferases CBP and p300. We first describe clinical and genetic aspects of the syndrome to later focus on the insight provided by the research in animal models of this disease. These studies have not only clarified the molecular etiology of RSTS and helped to dissect the developmental and adult components of the syndrome but also contributed to outline some important connections between epigenetics and cognition. We finally discuss how this body of research has opened new venues for the therapeutic intervention of this currently untreatable disease and present some of the outstanding questions in the field. We believe that the progress in the understanding of this rare disorder also has important implications for other intellectual disability disorders that share an epigenetic origin.
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Affiliation(s)
- Jose P Lopez-Atalaya
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Alicante, Spain
| | - Luis M Valor
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Alicante, Spain
| | - Angel Barco
- Instituto de Neurociencias, Universidad Miguel Hernández-Consejo Superior de Investigaciones Científicas, Alicante, Spain
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222
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A large-scale in vivo RNAi screen to identify genes involved in Notch-mediated follicle cell differentiation and cell cycle switches. Sci Rep 2015. [PMID: 26205122 PMCID: PMC4513280 DOI: 10.1038/srep12328] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023] Open
Abstract
During Drosophila oogenesis, follicle cells sequentially undergo three distinct cell-cycle programs: the mitotic cycle, endocycle, and gene amplification. Notch signaling plays a central role in regulating follicle-cell differentiation and cell-cycle switches; its activation is essential for the mitotic cycle/endocycle (M/E) switch. Cut, a linker between Notch signaling and cell-cycle regulators, is specifically downregulated by Notch during the endocycle stage. To determine how signaling pathways coordinate during the M/E switch and to identify novel genes involved in follicle cell differentiation, we performed an in vivo RNAi screen through induced knockdown of gene expression and examination of Cut expression in follicle cells. We screened 2205 RNAi lines and found 33 genes regulating Cut expression during the M/E switch. These genes were confirmed with the staining of two other Notch signaling downstream factors, Hindsight and Broad, and validated with multiple independent RNAi lines. We applied gene ontology software to find enriched biological meaning and compared our results with other publications to find conserved genes across tissues. Specifically, we found earlier endocycle entry in anterior follicle cells than those in the posterior, identified that the insulin-PI3K pathway participates in the precise M/E switch, and suggested Nejire as a cofactor of Notch signaling during oogenesis.
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223
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Han L, Pandian GN, Chandran A, Sato S, Taniguchi J, Kashiwazaki G, Sawatani Y, Hashiya K, Bando T, Xu Y, Qian X, Sugiyama H. A Synthetic DNA-Binding Domain Guides Distinct Chromatin-Modifying Small Molecules to Activate an Identical Gene Network. Angew Chem Int Ed Engl 2015; 54:8700-3. [PMID: 26094767 DOI: 10.1002/anie.201503607] [Citation(s) in RCA: 33] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/20/2015] [Indexed: 12/20/2022]
Abstract
Synthetic dual-function ligands targeting specific DNA sequences and histone-modifying enzymes were applied to achieve regulatory control over multi-gene networks in living cells. Unlike the broad array of targeting small molecules for histone deacetylases (HDACs), few modulators are known for histone acetyltransferases (HATs), which play a central role in transcriptional control. As a novel chemical approach to induce selective HAT-regulated genes, we conjugated a DNA-binding domain (DBD) "I" to N-(4-chloro-3-trifluoromethyl-phenyl)-2-ethoxy-benzamide (CTB), an artificial HAT activator. In vitro enzyme activity assays and microarray studies were used to demonstrate that distinct functional small molecules could be transformed to have identical bioactivity when conjugated with a targeting DBD. This proof-of-concept synthetic strategy validates the switchable functions of HDACs and HATs in gene regulation and provides a molecular basis for developing versatile bioactive ligands.
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Affiliation(s)
- Le Han
- Department of Chemistry, Graduate School of Science, Kyoto University Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan).,Shanghai Key Laboratory of Chemical Biology, State Key Laboratory of Bioreactor Engineering, School of Pharmacy, East China University of Science and Technology, Meilong Road 130, Shanghai, 200237 (China)
| | - Ganesh N Pandian
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University Yoshida-Ushinomiyacho, Sakyo-ku, Kyoto 606-8501 (Japan)
| | - Anandhakumar Chandran
- Department of Chemistry, Graduate School of Science, Kyoto University Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)
| | - Shinsuke Sato
- Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University Yoshida-Ushinomiyacho, Sakyo-ku, Kyoto 606-8501 (Japan)
| | - Junichi Taniguchi
- Department of Chemistry, Graduate School of Science, Kyoto University Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)
| | - Gengo Kashiwazaki
- Department of Chemistry, Graduate School of Science, Kyoto University Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)
| | - Yoshito Sawatani
- Department of Chemistry, Graduate School of Science, Kyoto University Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)
| | - Kaori Hashiya
- Department of Chemistry, Graduate School of Science, Kyoto University Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)
| | - Toshikazu Bando
- Department of Chemistry, Graduate School of Science, Kyoto University Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan)
| | - Yufang Xu
- Shanghai Key Laboratory of Chemical Biology, State Key Laboratory of Bioreactor Engineering, School of Pharmacy, East China University of Science and Technology, Meilong Road 130, Shanghai, 200237 (China)
| | - Xuhong Qian
- Shanghai Key Laboratory of Chemical Biology, State Key Laboratory of Bioreactor Engineering, School of Pharmacy, East China University of Science and Technology, Meilong Road 130, Shanghai, 200237 (China)
| | - Hiroshi Sugiyama
- Department of Chemistry, Graduate School of Science, Kyoto University Kitashirakawa-Oiwakecho, Sakyo-ku, Kyoto 606-8502 (Japan). .,Institute for Integrated Cell-Material Sciences (WPI-iCeMS), Kyoto University Yoshida-Ushinomiyacho, Sakyo-ku, Kyoto 606-8501 (Japan).
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Han L, Pandian GN, Chandran A, Sato S, Taniguchi J, Kashiwazaki G, Sawatani Y, Hashiya K, Bando T, Xu Y, Qian X, Sugiyama H. A Synthetic DNA-Binding Domain Guides Distinct Chromatin-Modifying Small Molecules to Activate an Identical Gene Network. Angew Chem Int Ed Engl 2015. [DOI: 10.1002/ange.201503607] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
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225
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Yang XJ. MOZ and MORF acetyltransferases: Molecular interaction, animal development and human disease. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2015; 1853:1818-26. [PMID: 25920810 DOI: 10.1016/j.bbamcr.2015.04.014] [Citation(s) in RCA: 77] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/19/2015] [Revised: 04/17/2015] [Accepted: 04/22/2015] [Indexed: 01/16/2023]
Abstract
Lysine residues are subject to many forms of covalent modification and one such modification is acetylation of the ε-amino group. Initially identified on histone proteins in the 1960s, lysine acetylation is now considered as an important form of post-translational modification that rivals phosphorylation. However, only about a dozen of human lysine acetyltransferases have been identified. Among them are MOZ (monocytic leukemia zinc finger protein; a.k.a. MYST3 and KAT6A) and its paralog MORF (a.k.a. MYST4 and KAT6B). Although there is a distantly related protein in Drosophila and sea urchin, these two enzymes are vertebrate-specific. They form tetrameric complexes with BRPF1 (bromodomain- and PHD finger-containing protein 1) and two small non-catalytic subunits. These two acetyltransferases and BRPF1 play key roles in various developmental processes; for example, they are important for development of hematopoietic and neural stem cells. The human KAT6A and KAT6B genes are recurrently mutated in leukemia, non-hematologic malignancies, and multiple developmental disorders displaying intellectual disability and various other abnormalities. In addition, the BRPF1 gene is mutated in childhood leukemia and adult medulloblastoma. Therefore, these two acetyltransferases and their partner BRPF1 are important in animal development and human disease.
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Affiliation(s)
- Xiang-Jiao Yang
- The Rosalind & Morris Goodman Cancer Research Center, McGill University, Montreal, Quebec H3A 1A3, Canada; Department of Medicine, McGill University, Montreal, Quebec H3A 1A3, Canada; Department of Biochemistry, McGill University, Montreal, Quebec H3A 1A3, Canada; McGill University Health Center, Montreal, Quebec H3A 1A3, Canada.
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226
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Jang SW, Lim SG, Suk K, Lee WH. Activation of lymphotoxin-beta receptor enhances the LPS-induced expression of IL-8 through NF-κB and IRF-1. Immunol Lett 2015; 165:63-9. [PMID: 25887375 DOI: 10.1016/j.imlet.2015.04.001] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/19/2015] [Accepted: 04/06/2015] [Indexed: 10/23/2022]
Abstract
Lymphotoxin-beta receptor (LTβR), a receptor for LIGHT and LTα1β2, is expressed on the epithelial, stromal, and myeloid cells. LTβR is known to affect the lymphoid organ development and immune homeostasis. However, its role in macrophage function has not been sufficiently elucidated. The effect of LTβR stimulation in the inflammatory activation of macrophages was investigated by treating the human macrophage-like cell line THP-1 with LTβR-specific monoclonal antibody. Interestingly, combined treatment with anti-LTβR antibody and LPS caused the synergistic induction of IL-8 expression at the transcriptional level. Analysis indicated that nuclear factor (NF)-κB activity was enhanced via the mitogen-activated protein kinase (MAPK) and glycogen synthase kinase (GSK)-3β/cAMP response element binding protein (CREB) pathways. In addition, LTβR stimulation induced the expression of interferon regulatory factor (IRF)-1, one of the major transcription factors of IL-8 gene. Down-regulation of IRF-1 expression reduced the enhancing effect caused by LTβR stimulation. This indicates that the LTβR stimulation enhances the LPS-induced expression of IL-8 via the combined action of NF-κB and IRF-1.
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Affiliation(s)
- Seok-Won Jang
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Su-Geun Lim
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea
| | - Kyoungho Suk
- Department of Pharmacology, Brain Science & Engineering Institute, BK21 Plus KNU Biomedical Convergence Program, Kyungpook National University School of Medicine, Daegu 700-422, Republic of Korea
| | - Won-Ha Lee
- School of Life Sciences, BK21 Plus KNU Creative BioResearch Group, Kyungpook National University, Daegu 702-701, Republic of Korea.
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227
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Patel S, Pongkulapa T, Yin PT, Pandian GN, Rathnam C, Bando T, Vaijayanthi T, Sugiyama H, Lee KB. Integrating epigenetic modulators into NanoScript for enhanced chondrogenesis of stem cells. J Am Chem Soc 2015; 137:4598-601. [PMID: 25789886 PMCID: PMC5702886 DOI: 10.1021/ja511298n] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
N-(4-Chloro-3-(trifluoromethyl)phenyl)-2-ethoxybenzamide (CTB) is a small molecule that functions by altering the chromatin architecture to modulate gene expression. We report a new CTB derivative with increased solubility and demonstrate CTB's functionality by conjugating it on the recently established NanoScript platform to enhance gene expression and induce stem cell differentiation. NanoScript is a nanoparticle-based artificial transcription factor that emulates the structure and function of transcription factor proteins (TFs) to effectively regulate endogenous gene expression. Modifying NanoScript with CTB will more closely replicate the TF structure and enhance CTB functionality and gene expression. To this end, we first conjugated CTB onto NanoScript and initiated a time-dependent increase in histone acetyltransferase activity. Next, because CTB is known to trigger the pathway involved in regulating Sox9, a master regulator of chondrogenic differentiation, we modifed a Sox9-specific NanoScript with CTB to enhance chondrogenic gene activity and differentiation. Because NanoScript is a tunable and robust platform, it has potential for various gene-regulating applications, such as stem cell differentiation.
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Affiliation(s)
- Sahishnu Patel
- Department of Chemistry and Chemical Biology, The State University of New Jersey, Piscataway, New Jersey 08854-8087, United States
| | - Thanapat Pongkulapa
- Department of Chemistry and Chemical Biology, The State University of New Jersey, Piscataway, New Jersey 08854-8087, United States
| | - Perry T. Yin
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8087, United States
| | - Ganesh N. Pandian
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501, Japan
| | - Christopher Rathnam
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8087, United States
| | - Toshikazu Bando
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8501, Japan
| | - Thangavel Vaijayanthi
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8501, Japan
| | - Hiroshi Sugiyama
- Institute for Integrated Cell-Material Sciences (iCeMS), Kyoto University, Kyoto 606-8501, Japan
- Department of Chemistry, Graduate School of Science, Kyoto University, Kyoto 606-8501, Japan
| | - Ki-Bum Lee
- Department of Chemistry and Chemical Biology, The State University of New Jersey, Piscataway, New Jersey 08854-8087, United States
- Department of Biomedical Engineering, Rutgers, The State University of New Jersey, Piscataway, New Jersey 08854-8087, United States
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228
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Lee JS, Byun CK, Kim H, Lim BC, Hwang H, Choi JE, Hwang YS, Seong MW, Park SS, Kim KJ, Chae JH. Clinical and mutational spectrum in Korean patients with Rubinstein-Taybi syndrome: the spectrum of brain MRI abnormalities. Brain Dev 2015; 37:402-8. [PMID: 25108505 DOI: 10.1016/j.braindev.2014.07.007] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2014] [Revised: 06/23/2014] [Accepted: 07/14/2014] [Indexed: 01/27/2023]
Abstract
OBJECTIVE Rubinstein-Taybi syndrome (RSTS) is one of the neurodevelopmental disorders caused by mutations of epigenetic genes. The CREBBP gene is the most common causative gene, encoding the CREB-binding protein with histone acetyltransferase (HAT) activity, an epigenetic modulator. To date, there have been few reports on the structural abnormalities of the brain in RSTS patients. In addition, there are no reports on the analysis of CREBBP mutations in Korean RSTS patients. PATIENTS AND METHODS We performed mutational analyses on 16 unrelated patients with RSTS, with diagnosis based on the typical clinical features. Their medical records and brain MRI images were reviewed retrospectively. RESULTS Ten of 16 patients (62.5%) had mutations in the CREBBP gene. The mutations included five frameshift mutations (31.2%), two nonsense mutations (12.5%), and three multiexon deletions (18.8%). There were no remarkable significant differences in the clinical features between those with and without a CREBBP mutation, although brain MRI abnormalities were more frequently observed in those with a CREBBP mutation. Seven of 10 patients in whom brain imaging was performed had structural abnormalities, including Chiari malformation type 1, thinning of the corpus callosum, and delayed myelination. There were no differences in delayed development or cognitive impairment between those with and without abnormal brain images, while epilepsy was involved in two patients who had abnormalities on brain MRI images. CONCLUSIONS We investigated the spectrum of CREBBP mutations in Korean patients with RSTS for the first time. Eight novel mutations extended the genetic spectrum of CREBBP mutations in RSTS patients. This is also the first study showing the prevalence and spectrum of abnormalities on brain MRI in RSTS patients.
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Affiliation(s)
- Jin Sook Lee
- Department of Pediatrics, Pediatric Clinical Neuroscience Center, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Christine K Byun
- Department of Pediatrics, Pediatric Clinical Neuroscience Center, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hunmin Kim
- Department of Pediatrics, Seoul National University Bundang Hospital, Seoul, Republic of Korea
| | - Byung Chan Lim
- Department of Pediatrics, Pediatric Clinical Neuroscience Center, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Hee Hwang
- Department of Pediatrics, Seoul National University Bundang Hospital, Seoul, Republic of Korea
| | - Ji Eun Choi
- Department of Pediatrics, SMG-SNU Boramae Hospital, Seoul, Republic of Korea
| | - Yong Seung Hwang
- Department of Pediatrics, Pediatric Clinical Neuroscience Center, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Moon-Woo Seong
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Sung Sup Park
- Department of Laboratory Medicine, Seoul National University Hospital, Seoul, Republic of Korea
| | - Ki Joong Kim
- Department of Pediatrics, Pediatric Clinical Neuroscience Center, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
| | - Jong-Hee Chae
- Department of Pediatrics, Pediatric Clinical Neuroscience Center, Seoul National University Children's Hospital, Seoul National University College of Medicine, Seoul, Republic of Korea.
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229
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Zhao LJ, Loewenstein PM, Green M. The adenovirus E1A oncoprotein N-terminal transcriptional repression domain enhances p300 autoacetylation and inhibits histone H3 Lys18 acetylation. Genes Cancer 2015; 6:30-7. [PMID: 25821559 PMCID: PMC4362482 DOI: 10.18632/genesandcancer.47] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2014] [Accepted: 01/07/2015] [Indexed: 11/25/2022] Open
Abstract
Expression of the adenovirus E1A N-terminal transcription repression domain alone (E1A 1-80) represses transcription from specific promoters such as HER2 [1] and from reconstituted chromatin [2]. Significantly, E1A 1-80 can induce the death of human breast cancer cells over-expressing the HER2 oncogene [1] as well as other cancer cells. Here, we report that E1A 1-80 alone is sufficient to inhibit H3K18 acetylation in vivo and p300-mediated H3K18 acetylation in reconstituted chromatin. Of interest, hypoacetylation of H3K18 has been correlated with the survival of tumor cells and the poor prognosis of many cancers [3, 4]. E1A 1-80 enhances p300 autoacetylation and concurrently inhibits H3K18 acetylation in chromatin in a dose-dependent manner. Pre-acetylation of p300 by incubation with acetyl-CoA alone reduces p300's ability to acetylate H3K18 in chromatin. Additional acetylation of p300 in the presence of E1A 1-80 produces stronger inhibition of H3K18 acetylation. These findings indicate that autoacetylation of p300 greatly reduces its ability to acetylate H3K18. The results reported here combined with our previous findings suggest that E1A can repress transcription by multiple strategies, including altering the chromatin modifying activity of p300 and dissociating TFIID from the TATA box thus disrupting formation of the transcription pre-initiation complex [5, 6]
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Affiliation(s)
- Ling-Jun Zhao
- Institute for Molecular Virology, Saint Louis University School of Medicine, Doisy research Center, St. Louis, Missouri
| | - Paul M Loewenstein
- Institute for Molecular Virology, Saint Louis University School of Medicine, Doisy research Center, St. Louis, Missouri
| | - Maurice Green
- Institute for Molecular Virology, Saint Louis University School of Medicine, Doisy research Center, St. Louis, Missouri
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230
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Rusconi D, Negri G, Colapietro P, Picinelli C, Milani D, Spena S, Magnani C, Silengo MC, Sorasio L, Curtisova V, Cavaliere ML, Prontera P, Stangoni G, Ferrero GB, Biamino E, Fischetto R, Piccione M, Gasparini P, Salviati L, Selicorni A, Finelli P, Larizza L, Gervasini C. Characterization of 14 novel deletions underlying Rubinstein-Taybi syndrome: an update of the CREBBP deletion repertoire. Hum Genet 2015; 134:613-26. [PMID: 25805166 DOI: 10.1007/s00439-015-1542-9] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/20/2015] [Accepted: 03/11/2015] [Indexed: 11/25/2022]
Abstract
Rubinstein-Taybi syndrome (RSTS) is a rare, clinically heterogeneous disorder characterized by cognitive impairment and several multiple congenital anomalies. The syndrome is caused by almost private point mutations in the CREBBP (~55% of cases) and EP300 (~8%) genes. The CREBBP mutational spectrum is variegated and characterized by point mutations (30-50 %) and deletions (~10%). The latter are diverse in size and genomic position and remove either the whole CREBBP gene and its flanking regions or only an intragenic portion. Here, we report 14 novel CREBBP deletions ranging from single exons to the whole gene and flanking regions which were identified by applying complementary cytomolecular techniques: fluorescence in situ hybridization, multiplex ligation-dependent probe amplification and array comparative genome hybridization, to a large cohort of RSTS patients. Deletions involving CREBBP account for 23% of our detected CREBBP mutations, making an important contribution to the mutational spectrum. Genotype-phenotype correlations revealed that patients with CREBBP deletions extending beyond this gene did not always have a more severe phenotype than patients harboring CREBBP point mutations, suggesting that neighboring genes play only a limited role in the etiopathogenesis of CREBBP-centerd contiguous gene syndrome. Accordingly, the extent of the deletion is not predictive of the severity of the clinical phenotype.
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Affiliation(s)
- Daniela Rusconi
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, Via A. di Rudinì, 8, 20142, Milan, Italy
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231
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Affiliation(s)
| | - Philip A. Cole
- Department
of Pharmacology
and Molecular Sciences, The Johns Hopkins
University School of Medicine, 725 North Wolfe Street, Hunterian 316, Baltimore, Maryland 21205, United States
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232
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Aubry S, Shin W, Crary JF, Lefort R, Qureshi YH, Lefebvre C, Califano A, Shelanski ML. Assembly and interrogation of Alzheimer's disease genetic networks reveal novel regulators of progression. PLoS One 2015; 10:e0120352. [PMID: 25781952 PMCID: PMC4363671 DOI: 10.1371/journal.pone.0120352] [Citation(s) in RCA: 74] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2014] [Accepted: 01/20/2015] [Indexed: 11/19/2022] Open
Abstract
Alzheimer's disease (AD) is a complex multifactorial disorder with poorly characterized pathogenesis. Our understanding of this disease would thus benefit from an approach that addresses this complexity by elucidating the regulatory networks that are dysregulated in the neural compartment of AD patients, across distinct brain regions. Here, we use a Systems Biology (SB) approach, which has been highly successful in the dissection of cancer related phenotypes, to reverse engineer the transcriptional regulation layer of human neuronal cells and interrogate it to infer candidate Master Regulators (MRs) responsible for disease progression. Analysis of gene expression profiles from laser-captured neurons from AD and controls subjects, using the Algorithm for the Reconstruction of Accurate Cellular Networks (ARACNe), yielded an interactome consisting of 488,353 transcription-factor/target interactions. Interrogation of this interactome, using the Master Regulator INference algorithm (MARINa), identified an unbiased set of candidate MRs causally responsible for regulating the transcriptional signature of AD progression. Experimental assays in autopsy-derived human brain tissue showed that three of the top candidate MRs (YY1, p300 and ZMYM3) are indeed biochemically and histopathologically dysregulated in AD brains compared to controls. Our results additionally implicate p53 and loss of acetylation homeostasis in the neurodegenerative process. This study suggests that an integrative, SB approach can be applied to AD and other neurodegenerative diseases, and provide significant novel insight on the disease progression.
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Affiliation(s)
- Soline Aubry
- Taub Institute for Research on Alzheimer's Disease & the Aging Brain and the Department of Pathology & Cell Biology, Columbia University, New York, NY, 10032, United States of America
| | - William Shin
- Department of Systems Biology, Columbia University, New York, NY, 10032, United States of America
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, 10032, United States of America
- Department of Biological Sciences, Columbia University, New York, NY, 10027, United States of America
| | - John F. Crary
- Taub Institute for Research on Alzheimer's Disease & the Aging Brain and the Department of Pathology & Cell Biology, Columbia University, New York, NY, 10032, United States of America
| | - Roger Lefort
- Taub Institute for Research on Alzheimer's Disease & the Aging Brain and the Department of Pathology & Cell Biology, Columbia University, New York, NY, 10032, United States of America
| | - Yasir H. Qureshi
- Taub Institute for Research on Alzheimer's Disease & the Aging Brain and the Department of Pathology & Cell Biology, Columbia University, New York, NY, 10032, United States of America
| | - Celine Lefebvre
- Department of Systems Biology, Columbia University, New York, NY, 10032, United States of America
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, 10032, United States of America
- Inserm Unit U981, Institut Gustave Roussy, 94805, Villejuif, France
| | - Andrea Califano
- Department of Systems Biology, Columbia University, New York, NY, 10032, United States of America
- Herbert Irving Comprehensive Cancer Center, Columbia University, New York, NY, 10032, United States of America
- Department of Biological Sciences, Columbia University, New York, NY, 10027, United States of America
| | - Michael L. Shelanski
- Taub Institute for Research on Alzheimer's Disease & the Aging Brain and the Department of Pathology & Cell Biology, Columbia University, New York, NY, 10032, United States of America
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233
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Xia J, Fang M, Wu X, Yang Y, Yu L, Xu H, Kong H, Tan Q, Wang H, Xie W, Xu Y. A2b adenosine signaling represses CIITA transcription via an epigenetic mechanism in vascular smooth muscle cells. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:665-76. [PMID: 25765819 DOI: 10.1016/j.bbagrm.2015.03.001] [Citation(s) in RCA: 18] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/22/2014] [Revised: 02/05/2015] [Accepted: 03/03/2015] [Indexed: 01/08/2023]
Abstract
Chronic inflammation plays a major role in the pathogenesis of atherosclerosis. Vascular smooth muscle cells (VSMC), by expressing and presenting major histocompatibility complex II (MHC II) molecules, help recruit T lymphocyte and initiate the inflammatory response within the vasculature. We have previously shown that VSMCs isolated from mice with deficient adenosine A2b receptor (A2b-null) exhibit higher expression of class II transactivator (CIITA), the master regulator of MHC II transcription, compared to wild type littermates. Here we report that activation of A2b adenosine signaling suppresses CIITA expression in human aortic smooth muscle cells. Down-regulation of CIITA expression was largely attributable to transcriptional repression of type III and IV promoters. Chromatin immunoprecipitation (ChIP) analyses revealed that A2b signaling repressed CIITA transcription by attenuating specific histone modifications on the CIITA promoters in a STAT1-dependent manner. STAT1 interacted with PCAF/GCN5, histone H3K9 acetyltransferases, and WDR5, a key component of the mammalian H3K4 methyltransferase complex, to activate CIITA transcription. A2b signaling prevented recruitment of PCAF/GCN5 and WDR5 to the CIITA promoters in a STAT1-dependent manner. In conclusion, our data suggest that adenosine A2b signaling represses CIITA transcription in VSMCs by manipulating the interaction between STAT1 and the epigenetic machinery.
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Affiliation(s)
- Jun Xia
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China; Department of Respiratory Medicine, Jiangsu Province Hospital of Traditional Chinese Medicine, China
| | - Mingming Fang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China; Department of Nursing, Jiangsu Jiankang Vocational University, Nanjing, China
| | - Xiaoyan Wu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China
| | - Yuyu Yang
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China; State Key Laboratory of Natural Medicines, China Pharmaceutical University, Nanjing, China
| | - Liming Yu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China
| | - Huihui Xu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China
| | - Hui Kong
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China
| | - Qi Tan
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China
| | - Hong Wang
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China.
| | - Weiping Xie
- Department of Respiratory Medicine, the First Affiliated Hospital of Nanjing Medical University, China.
| | - Yong Xu
- Key Laboratory of Cardiovascular Disease and Molecular Intervention, Department of Pathophysiology, Nanjing Medical University, China.
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234
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Heinz S, Romanoski CE, Benner C, Glass CK. The selection and function of cell type-specific enhancers. Nat Rev Mol Cell Biol 2015; 16:144-54. [PMID: 25650801 PMCID: PMC4517609 DOI: 10.1038/nrm3949] [Citation(s) in RCA: 670] [Impact Index Per Article: 74.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
The human body contains several hundred cell types, all of which share the same genome. In metazoans, much of the regulatory code that drives cell type-specific gene expression is located in distal elements called enhancers. Although mammalian genomes contain millions of potential enhancers, only a small subset of them is active in a given cell type. Cell type-specific enhancer selection involves the binding of lineage-determining transcription factors that prime enhancers. Signal-dependent transcription factors bind to primed enhancers, which enables these broadly expressed factors to regulate gene expression in a cell type-specific manner. The expression of genes that specify cell type identity and function is associated with densely spaced clusters of active enhancers known as super-enhancers. The functions of enhancers and super-enhancers are influenced by, and affect, higher-order genomic organization.
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Affiliation(s)
| | | | | | - Christopher K. Glass
- Department of Cellular and Molecular Medicine, UC San Diego
- Department of Medicine, UC San Diego
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235
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Yi P, Wang Z, Feng Q, Pintilie GD, Foulds CE, Lanz RB, Ludtke SJ, Schmid MF, Chiu W, O'Malley BW. Structure of a biologically active estrogen receptor-coactivator complex on DNA. Mol Cell 2015; 57:1047-1058. [PMID: 25728767 DOI: 10.1016/j.molcel.2015.01.025] [Citation(s) in RCA: 108] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2014] [Revised: 01/05/2015] [Accepted: 01/20/2015] [Indexed: 12/17/2022]
Abstract
Estrogen receptor (ER/ESR1) is a transcription factor critical for development, reproduction, metabolism, and cancer. ER function hinges on its ability to recruit primary and secondary coactivators, yet structural information on the full-length receptor-coactivator complex to complement preexisting and sometimes controversial biochemical information is lacking. Here, we use cryoelectron microscopy (cryo-EM) to determine the quaternary structure of an active complex of DNA-bound ERα, steroid receptor coactivator 3 (SRC-3/NCOA3), and a secondary coactivator (p300/EP300). Our structural model suggests the following assembly mechanism for the complex: each of the two ligand-bound ERα monomers independently recruits one SRC-3 protein via the transactivation domain of ERα; the two SRC-3s in turn bind to different regions of one p300 protein through multiple contacts. We also present structural evidence for the location of activation function 1 (AF-1) in a full-length nuclear receptor, which supports a role for AF-1 in SRC-3 recruitment.
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Affiliation(s)
- Ping Yi
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA; Clayton Foundation for Research, Houston, TX 77056, USA
| | - Zhao Wang
- National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Qin Feng
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Grigore D Pintilie
- National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Charles E Foulds
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Rainer B Lanz
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Steven J Ludtke
- National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Michael F Schmid
- National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA
| | - Wah Chiu
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA; National Center for Macromolecular Imaging, Verna and Marrs McLean Department of Biochemistry and Molecular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
| | - Bert W O'Malley
- Department of Molecular and Cellular Biology, Baylor College of Medicine, Houston, TX 77030, USA.
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236
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Maeshima K, Kaizu K, Tamura S, Nozaki T, Kokubo T, Takahashi K. The physical size of transcription factors is key to transcriptional regulation in chromatin domains. JOURNAL OF PHYSICS. CONDENSED MATTER : AN INSTITUTE OF PHYSICS JOURNAL 2015; 27:064116. [PMID: 25563431 DOI: 10.1088/0953-8984/27/6/064116] [Citation(s) in RCA: 42] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/04/2023]
Abstract
Genetic information, which is stored in the long strand of genomic DNA as chromatin, must be scanned and read out by various transcription factors. First, gene-specific transcription factors, which are relatively small (∼50 kDa), scan the genome and bind regulatory elements. Such factors then recruit general transcription factors, Mediators, RNA polymerases, nucleosome remodellers, and histone modifiers, most of which are large protein complexes of 1-3 MDa in size. Here, we propose a new model for the functional significance of the size of transcription factors (or complexes) for gene regulation of chromatin domains. Recent findings suggest that chromatin consists of irregularly folded nucleosome fibres (10 nm fibres) and forms numerous condensed domains (e.g., topologically associating domains). Although the flexibility and dynamics of chromatin allow repositioning of genes within the condensed domains, the size exclusion effect of the domain may limit accessibility of DNA sequences by transcription factors. We used Monte Carlo computer simulations to determine the physical size limit of transcription factors that can enter condensed chromatin domains. Small gene-specific transcription factors can penetrate into the chromatin domains and search their target sequences, whereas large transcription complexes cannot enter the domain. Due to this property, once a large complex binds its target site via gene-specific factors it can act as a 'buoy' to keep the target region on the surface of the condensed domain and maintain transcriptional competency. This size-dependent specialization of target-scanning and surface-tethering functions could provide novel insight into the mechanisms of various DNA transactions, such as DNA replication and repair/recombination.
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Affiliation(s)
- Kazuhiro Maeshima
- Biological Macromolecules Laboratory, Structural Biology Center, National Institute of Genetics, Mishima, Shizuoka 411-8540, Japan. Department of Genetics, School of Life Science, Graduate University for Advanced Studies (Sokendai), Mishima, Shizuoka 411-8540, Japan
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237
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Fang F, Xu Y, Chew KK, Chen X, Ng HH, Matsudaira P. Coactivators p300 and CBP maintain the identity of mouse embryonic stem cells by mediating long-range chromatin structure. Stem Cells 2015; 32:1805-16. [PMID: 24648406 DOI: 10.1002/stem.1705] [Citation(s) in RCA: 45] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2013] [Revised: 11/25/2013] [Accepted: 12/22/2013] [Indexed: 11/07/2022]
Abstract
Master transcription factors Oct4, Sox2, and Nanog are required to maintain the pluripotency and self-renewal of embryonic stem cells (ESCs) by regulating a specific transcriptional network. A few other transcription factors have been shown to be important in ESCs by interacting with these master transcription factors; however, little is known about the transcriptional mechanisms regulated by coregulators (coactivators and corepressors). In this study, we examined the function of two highly homologous coactivators, p300 and CREB-binding protein (CBP), in ESCs. We find that these two coactivators play redundant roles in maintaining the undifferentiated state of ESCs. They are recruited by Nanog through physical interaction to Nanog binding loci, mediating the formation of long-range chromatin looping structures, which is essential to maintain ESC-specific gene expression. Further functional studies reveal that the p300/CBP binding looping fragments contain enhancer activities, suggesting that the formation of p300/CBP-mediated looping structures may recruit distal enhancers to create a concentration of factors for the transcription activation of genes that are involved in self-renewal and pluripotency. Overall, these results provide a total new insight into the transcriptional regulation mechanism of coactivators p300 and CBP in ESCs, which is important in maintaining self-renewal and pluripotency, by mediating the formation of higher order chromosome structures.
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Affiliation(s)
- Fang Fang
- Computation and Systems Biology, Singapore-MIT Alliance, Singapore, Singapore
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238
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Reed SM, Quelle DE. p53 Acetylation: Regulation and Consequences. Cancers (Basel) 2014; 7:30-69. [PMID: 25545885 PMCID: PMC4381250 DOI: 10.3390/cancers7010030] [Citation(s) in RCA: 227] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2014] [Accepted: 12/12/2014] [Indexed: 12/11/2022] Open
Abstract
Post-translational modifications of p53 are critical in modulating its tumor suppressive functions. Ubiquitylation, for example, plays a major role in dictating p53 stability, subcellular localization and transcriptional vs. non-transcriptional activities. Less is known about p53 acetylation. It has been shown to govern p53 transcriptional activity, selection of growth inhibitory vs. apoptotic gene targets, and biological outcomes in response to diverse cellular insults. Yet recent in vivo evidence from mouse models questions the importance of p53 acetylation (at least at certain sites) as well as canonical p53 functions (cell cycle arrest, senescence and apoptosis) to tumor suppression. This review discusses the cumulative findings regarding p53 acetylation, with a focus on the acetyltransferases that modify p53 and the mechanisms regulating their activity. We also evaluate what is known regarding the influence of other post-translational modifications of p53 on its acetylation, and conclude with the current outlook on how p53 acetylation affects tumor suppression. Due to redundancies in p53 control and growing understanding that individual modifications largely fine-tune p53 activity rather than switch it on or off, many questions still remain about the physiological importance of p53 acetylation to its role in preventing cancer.
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Affiliation(s)
- Sara M Reed
- Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
| | - Dawn E Quelle
- Department of Pharmacology, The University of Iowa Carver College of Medicine, Iowa City, IA 52242, USA.
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239
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Spena S, Milani D, Rusconi D, Negri G, Colapietro P, Elcioglu N, Bedeschi F, Pilotta A, Spaccini L, Ficcadenti A, Magnani C, Scarano G, Selicorni A, Larizza L, Gervasini C. Insights into genotype-phenotype correlations from CREBBP point mutation screening in a cohort of 46 Rubinstein-Taybi syndrome patients. Clin Genet 2014; 88:431-40. [PMID: 25388907 DOI: 10.1111/cge.12537] [Citation(s) in RCA: 43] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2014] [Revised: 11/05/2014] [Accepted: 11/07/2014] [Indexed: 12/01/2022]
Abstract
The genetic basis of Rubinstein-Taybi syndrome (RSTS), a rare, sporadic, clinically heterogeneous disorder characterized by cognitive impairment and a wide spectrum of multiple congenital anomalies, is primarily due to private mutations in CREBBP (approximately 55% of cases) or EP300 (approximately 8% of cases). Herein, we report the clinical and the genetic data taken from a cohort of 46 RSTS patients, all carriers of CREBBP point mutations. Molecular analysis revealed 45 different gene alterations including 31 inactivating (21 frameshift and 10 nonsense), 10 missense and 4 splicing mutations. Bioinformatic tools and transcript analyses were used to predict the functional effects of missense and splicing alterations. Of the 45 mutations, 42 are unreported and 3 were described previously. Recurrent mutations maybe a key tool in addressing genotype-phenotype correlations in patients sharing the same defects (at the genomic or transcript level) and specific clinical signs, demonstrated here in two cases. The clinical data of our cohort evidenced frequent signs such as arched eyebrows, epicanthus, synophrys and/or frontal hypertrichosis and broad phalanges that, previously overlooked in RSTS diagnosis, now could be considered. Some suggested correlations between organ-specific anomalies and affected CREB-binding protein domains broaden the RSTS clinical spectrum and perhaps will enhance patient follow-up and clinical care.
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Affiliation(s)
- S Spena
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, Milano, Italy
| | - D Milani
- Pediatric Highly Intensive Care Unit, Fondazione IRCCS Ca' Granda, Ospedale Maggiore, Policlinico, Milano, Italy
| | - D Rusconi
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, Milano, Italy
| | - G Negri
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, Milano, Italy
| | - P Colapietro
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, Milano, Italy
| | - N Elcioglu
- Department of Pediatrics, Marmara University School of Medicine, Istanbul, Turkey
| | - F Bedeschi
- Clinical Genetics Unit, Fondazione IRCCS Ca' Granda, Ospedale Maggiore Policlinico, Milano, Italy
| | - A Pilotta
- Centro di Auxoendocrinologia, Department of Paediatrics, Spedali Civili, Brescia, Italy
| | - L Spaccini
- Department of Obstetrics and Gynecology, Children's Hospital V. Buzzi, Milano, Italy
| | - A Ficcadenti
- Rare diseases Regional Centre, Pediatric Institute of Maternal-Infantile Sciences Department, Polytechnic University of Marche, Salesi Hospital of United Hospitals of Ancona, Ancona, Italy
| | - C Magnani
- Neonatology and Neonatal Intensive Care Unit, Maternal and Child Department, Parma University, Parma, Italy
| | - G Scarano
- Medical Genetics Department, Gaetano Rummo Hospital, Benevento, Italy
| | - A Selicorni
- Department of Pediatrics, Università Milano Bicocca, Fondazione MBBM, San Gerardo Hospital, Monza, Italy
| | - L Larizza
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, Milano, Italy.,Laboratory of Medical Cytogenetics and Molecular Genetics, IRCCS Istituto Auxologico Italiano, Milano, Italy
| | - C Gervasini
- Medical Genetics, Department of Health Sciences, Università degli Studi di Milano, Milano, Italy
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240
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Parlato R, Mandl C, Hölzl-Wenig G, Liss B, Tucker KL, Ciccolini F. Regulation of proliferation and histone acetylation in embryonic neural precursors by CREB/CREM signaling. NEUROGENESIS 2014; 1:e970883. [PMID: 27504469 PMCID: PMC4973597 DOI: 10.4161/23262125.2014.970883] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/19/2014] [Revised: 08/05/2014] [Accepted: 09/26/2014] [Indexed: 12/26/2022]
Abstract
The transcription factor CREB (cAMP-response element binding protein) regulates differentiation, migration, survival and activity-dependent gene expression in the developing and mature nervous system. However, its specific role in the proliferation of embryonic neural progenitors is still not completely understood. Here we investigated how CREB regulates proliferation of mouse embryonic neural progenitors by a conditional mutant lacking Creb gene in neural progenitors. In parallel, we explored possible compensatory effects by the genetic ablation of another member of the same gene family, the cAMP-responsive element modulator (Crem). We show that CREB loss differentially impaired the proliferation, clonogenic potential and self-renewal of precursors derived from the ganglionic eminence (GE), in comparison to those derived from the cortex. This phenotype was associated with a specific reduction of histone acetylation in the GE of CREB mutant mice, and this reduction was rescued in vivo by inhibition of histone deacetylation. These observations indicate that the impaired proliferation could be caused by a reduced acetyltransferase activity in Creb conditional knock-out mice. These findings support a crucial role of CREB in controlling embryonic neurogenesis and propose a novel mechanism by which CREB regulates embryonic neural development.
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Affiliation(s)
- Rosanna Parlato
- Institute of Applied Physiology; University of Ulm; Ulm, Germany; Dept. of Molecular Biology of the Cell I; DKFZ-ZMBH Alliance; German Cancer Research Center; Heidelberg, Germany; Institute of Anatomy and Cell Biology; Interdisciplinary Center for Neurosciences (IZN); University of Heidelberg; Heidelberg, Germany
| | - Claudia Mandl
- Department of Neurobiology; Interdisciplinary Center for Neurosciences (IZN); University of Heidelberg ; Heidelberg, Germany
| | - Gabriele Hölzl-Wenig
- Department of Neurobiology; Interdisciplinary Center for Neurosciences (IZN); University of Heidelberg ; Heidelberg, Germany
| | - Birgit Liss
- Institute of Applied Physiology; University of Ulm ; Ulm, Germany
| | - Kerry L Tucker
- Institute of Anatomy and Cell Biology; Interdisciplinary Center for Neurosciences (IZN); University of Heidelberg; Heidelberg, Germany; Kerry L Tucker's current affiliation is the Center for Excellence in the Neurosciences, Dept. of Biomedical Sciences, College of Osteopathic Medicine, University of New England, Biddeford, ME, USA
| | - Francesca Ciccolini
- Department of Neurobiology; Interdisciplinary Center for Neurosciences (IZN); University of Heidelberg ; Heidelberg, Germany
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241
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Tsuchiya R, Tanaka T, Hozumi Y, Nakano T, Okada M, Topham MK, Iino M, Goto K. Downregulation of diacylglycerol kinase ζ enhances activation of cytokine-induced NF-κB signaling pathway. BIOCHIMICA ET BIOPHYSICA ACTA-MOLECULAR CELL RESEARCH 2014; 1853:361-9. [PMID: 25450975 DOI: 10.1016/j.bbamcr.2014.11.011] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/11/2014] [Revised: 10/31/2014] [Accepted: 11/10/2014] [Indexed: 01/06/2023]
Abstract
The transcription factor NF-κB family serves as a key component of many pathophysiological events such as innate and adaptive immune response, inflammation, apoptosis, and oncogenesis. Various cell signals trigger activation of the regulatory mechanisms of NF-κB, resulting in its nuclear translocation and transcriptional initiation. The diacylglycerol kinase (DGK) family, a lipid second messenger-metabolizing enzyme in phosphoinositide signaling, is shown to regulate widely various cellular processes. Results of recent studies suggest that one family member, DGKζ, is closely involved in immune and inflammatory responses. Nevertheless, little is known about the regulatory mechanism of DGKζ on NF-κB pathway in cytokine-induced inflammatory signaling. This study shows that siRNA-mediated DGKζ knockdown in HeLa cells facilitates degradation of IκB, followed by nuclear translocation of NF-κB p65 subunit. In addition, DGKζ-deficient MEFs show upregulation of p65 subunit phosphorylation at Serine 468 and 536 and its interaction with CBP transcriptional coactivator upon TNF-α stimulation. These modifications of p65 subunit might engender enhanced NF-κB transcriptional reporter assay of DGKζ knockdown cells. These findings provide further insight into the regulatory mechanisms of cytokine-induced NF-κB activation.
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Affiliation(s)
- Rieko Tsuchiya
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan; Department of Dentistry, Oral and Maxillofacial Plastic and Reconstructive Surgery, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Toshiaki Tanaka
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Yasukazu Hozumi
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Tomoyuki Nakano
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Masashi Okada
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Matthew K Topham
- Huntsman Cancer Institute, Department of Oncological Sciences, University of Utah, Salt Lake City, UT 84112, USA
| | - Mitsuyoshi Iino
- Department of Dentistry, Oral and Maxillofacial Plastic and Reconstructive Surgery, Yamagata University School of Medicine, Yamagata 990-9585, Japan
| | - Kaoru Goto
- Department of Anatomy and Cell Biology, Yamagata University School of Medicine, Yamagata 990-9585, Japan.
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242
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Liu HJ, Wang T, Li QM, Guan XY, Xu Q. Knock-down of p300 decreases the proliferation and odontogenic differentiation potentiality of HDPCs. Int Endod J 2014; 48:976-85. [PMID: 25288362 DOI: 10.1111/iej.12392] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/26/2014] [Accepted: 10/02/2014] [Indexed: 01/17/2023]
Abstract
AIM To investigate the role of p300 in the regulation of proliferation and odontogenic differentiation of human dental pulp cells (HDPCs). METHODOLOGY The recombinant lentiviral vector pshRNA-copGFP was used to knock-down p300 expression in HDPCs. Protein level of acetylated H3 was detected. The proliferation of HDPCs was measured using the CCK8 assay. The cell cycle and apoptosis were analysed using flow cytometry and TUNEL staining, respectively. The expression levels of Cdc25A, p21(waf1) and the cleaved products of caspase 3 and caspase 7 were determined utilizing real-time quantitative polymerase chain reaction and Western blotting analysis. The alkaline phosphatase (ALP) activity was measured, and the formation of mineralized nodules was assessed using alizarin red staining after the induction of odontogenic differentiation of HDPCs. The expression levels of the odontogenic differentiation markers DMP-1, DSPP and DSP were detected utilizing real-time quantitative polymerase chain reaction and Western blotting analysis. RESULTS After p300 was knocked down in HDPCs, p300 was significantly down-regulated at both the mRNA and protein levels, and histone H3 acetylation was reduced. The proliferation capacity of HDPCs was suppressed in p300 knock-down groups. The cells were arrested in the G0/G1 phase of the cell cycle, and cell apoptosis was triggered. ALP activity, the formation of mineralized nodules and the expression levels of DMP-1, DSPP and DSP were all decreased in p300-knock-down HDPCs undergoing odontogenic differentiation. CONCLUSION Knocking down p300 restrains the proliferation and odontogenic differentiation potentiality of HDPCs.
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Affiliation(s)
- H J Liu
- Guanghua School of Stomatology & Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - T Wang
- Guanghua School of Stomatology & Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Q M Li
- Guanghua School of Stomatology & Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - X Y Guan
- Guanghua School of Stomatology & Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
| | - Q Xu
- Guanghua School of Stomatology & Guangdong Provincial Key Laboratory of Stomatology, Sun Yat-sen University, Guangzhou, China
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243
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NAA10 controls osteoblast differentiation and bone formation as a feedback regulator of Runx2. Nat Commun 2014; 5:5176. [DOI: 10.1038/ncomms6176] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/22/2014] [Accepted: 09/08/2014] [Indexed: 12/11/2022] Open
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244
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Dahlin JL, Chen X, Walters MA, Zhang Z. Histone-modifying enzymes, histone modifications and histone chaperones in nucleosome assembly: Lessons learned from Rtt109 histone acetyltransferases. Crit Rev Biochem Mol Biol 2014; 50:31-53. [PMID: 25365782 DOI: 10.3109/10409238.2014.978975] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
During DNA replication, nucleosomes ahead of replication forks are disassembled to accommodate replication machinery. Following DNA replication, nucleosomes are then reassembled onto replicated DNA using both parental and newly synthesized histones. This process, termed DNA replication-coupled nucleosome assembly (RCNA), is critical for maintaining genome integrity and for the propagation of epigenetic information, dysfunctions of which have been implicated in cancers and aging. In recent years, it has been shown that RCNA is carefully orchestrated by a series of histone modifications, histone chaperones and histone-modifying enzymes. Interestingly, many features of RCNA are also found in processes involving DNA replication-independent nucleosome assembly like histone exchange and gene transcription. In yeast, histone H3 lysine K56 acetylation (H3K56ac) is found in newly synthesized histone H3 and is critical for proper nucleosome assembly and for maintaining genomic stability. The histone acetyltransferase (HAT) regulator of Ty1 transposition 109 (Rtt109) is the sole enzyme responsible for H3K56ac in yeast. Much research has centered on this particular histone modification and histone-modifying enzyme. This Critical Review summarizes much of our current understanding of nucleosome assembly and highlights many important insights learned from studying Rtt109 HATs in fungi. We highlight some seminal features in nucleosome assembly conserved in mammalian systems and describe some of the lingering questions in the field. Further studying fungal and mammalian chromatin assembly may have important public health implications, including deeper understandings of human cancers and aging as well as the pursuit of novel anti-fungal therapies.
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Affiliation(s)
- Jayme L Dahlin
- Department of Molecular Pharmacology and Experimental Therapeutics, Mayo Clinic College of Medicine , Rochester, MN , USA
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245
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Jansma AL, Martinez-Yamout MA, Liao R, Sun P, Dyson HJ, Wright PE. The high-risk HPV16 E7 oncoprotein mediates interaction between the transcriptional coactivator CBP and the retinoblastoma protein pRb. J Mol Biol 2014; 426:4030-4048. [PMID: 25451029 DOI: 10.1016/j.jmb.2014.10.021] [Citation(s) in RCA: 46] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/29/2014] [Revised: 10/25/2014] [Accepted: 10/29/2014] [Indexed: 11/24/2022]
Abstract
The oncoprotein E7 from human papillomavirus (HPV) strains that confer high cancer risk mediates cell transformation by deregulating host cellular processes and activating viral gene expression through recruitment of cellular proteins such as the retinoblastoma protein (pRb) and the cyclic-AMP response element binding binding protein (CBP) and its paralog p300. Here we show that the intrinsically disordered N-terminal region of E7 from high-risk HPV16 binds the TAZ2 domain of CBP with greater affinity than E7 from low-risk HPV6b. HPV E7 and the tumor suppressor p53 compete for binding to TAZ2. The TAZ2 binding site in E7 overlaps the LxCxE motif that is crucial for interaction with pRb. While TAZ2 and pRb compete for binding to a monomeric E7 polypeptide, the full-length E7 dimer mediates an interaction between TAZ2 and pRb by promoting formation of a ternary complex. Cell-based assays show that expression of full-length HPV16 E7 promotes increased pRb acetylation and that this response depends both on the presence of CBP/p300 and on the ability of E7 to form a dimer. These observations suggest a model for the oncogenic effect of high-risk HPV16 E7. The disordered region of one E7 molecule in the homodimer interacts with the pocket domain of pRb, while the same region of the other E7 molecule binds the TAZ2 domain of CBP/p300. Through its ability to dimerize, E7 recruits CBP/p300 and pRb into a ternary complex, bringing the histone acetyltransferase domain of CBP/p300 into proximity to pRb and promoting acetylation, leading to disruption of cell cycle control.
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Affiliation(s)
- Ariane L Jansma
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Maria A Martinez-Yamout
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Rong Liao
- Department of Cell and Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Peiqing Sun
- Department of Cell and Molecular Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - H Jane Dyson
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA
| | - Peter E Wright
- Department of Integrative Structural and Computational Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA; Skaggs Institute for Chemical Biology, The Scripps Research Institute, 10550 North Torrey Pines Road, La Jolla, CA 92037, USA.
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246
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Mognol GP, de Araujo-Souza PS, Robbs BK, Teixeira LK, Viola JP. Transcriptional regulation of thec-Mycpromoter by NFAT1 involves negative and positive NFAT-responsive elements. Cell Cycle 2014; 11:1014-28. [DOI: 10.4161/cc.11.5.19518] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/04/2023] Open
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247
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Inhibition of p300 suppresses growth of breast cancer. Role of p300 subcellular localization. Exp Mol Pathol 2014; 97:411-24. [PMID: 25240203 DOI: 10.1016/j.yexmp.2014.09.019] [Citation(s) in RCA: 24] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2014] [Accepted: 09/12/2014] [Indexed: 02/03/2023]
Abstract
There is evidence that p300, a transcriptional co-factor and a lysine acetyl-transferase, could play a role both as an oncoprotein and as a tumor suppressor, although little is known regarding its role in breast cancer (BC). First we investigated the role p300 has on BC by performing pharmacological inhibition of p300 acetyl-transferase function and analyzing the effects on cell count, migration and invasion in LM3 murine breast cancer cell line and on tumor progression in a syngeneic murine model. We subsequently studied p300 protein expression in human BC biopsies and evaluated its correlation with clinical and histopathological parameters of the patients. We observed that inhibition of p300 induced apoptosis and reduced migration and invasion in cultured LM3 cells. Furthermore, a significant reduction in tumor burden, number of lung metastases and number of tumors invading the abdominal cavity was observed in a syngeneic tumor model of LM3 following treatment with the p300 inhibitor. This reduction in tumor burden was accompanied by a decrease in the mitotic index and Ki-67 levels and an increase in Bax expression. Moreover, the analysis of p300 expression in human BC samples showed that p300 immunoreactivity is significantly higher in the cancerous tissues than in the non-malignant mammary tissues and in the histologically normal adjacent tissues. Interestingly, p300 was observed in the cytoplasm, and the rate of cytoplasmic p300 was higher in BC than in non-tumor tissues. Importantly, we found that cytoplasmic localization of p300 is associated with a longer overall survival time of the patients. In conclusion, we demonstrated that inhibition of the acetylase function of p300 reduces both cell count and invasion in LM3 cells, and decreases tumor progression in the animal model. In addition, we show that the presence of p300 in the cytoplasm correlates with increased survival of patients suggesting that its nuclear localization is necessary for the pro-tumoral effects.
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248
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Aberger F, Ruiz i Altaba A. Context-dependent signal integration by the GLI code: the oncogenic load, pathways, modifiers and implications for cancer therapy. Semin Cell Dev Biol 2014; 33:93-104. [PMID: 24852887 PMCID: PMC4151135 DOI: 10.1016/j.semcdb.2014.05.003] [Citation(s) in RCA: 119] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2014] [Accepted: 05/12/2014] [Indexed: 01/10/2023]
Abstract
Canonical Hedgehog (HH) signaling leads to the regulation of the GLI code: the sum of all positive and negative functions of all GLI proteins. In humans, the three GLI factors encode context-dependent activities with GLI1 being mostly an activator and GLI3 often a repressor. Modulation of GLI activity occurs at multiple levels, including by co-factors and by direct modification of GLI structure. Surprisingly, the GLI proteins, and thus the GLI code, is also regulated by multiple inputs beyond HH signaling. In normal development and homeostasis these include a multitude of signaling pathways that regulate proto-oncogenes, which boost positive GLI function, as well as tumor suppressors, which restrict positive GLI activity. In cancer, the acquisition of oncogenic mutations and the loss of tumor suppressors - the oncogenic load - regulates the GLI code toward progressively more activating states. The fine and reversible balance of GLI activating GLI(A) and GLI repressing GLI(R) states is lost in cancer. Here, the acquisition of GLI(A) levels above a given threshold is predicted to lead to advanced malignant stages. In this review we highlight the concepts of the GLI code, the oncogenic load, the context-dependency of GLI action, and different modes of signaling integration such as that of HH and EGF. Targeting the GLI code directly or indirectly promises therapeutic benefits beyond the direct blockade of individual pathways.
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Affiliation(s)
- Fritz Aberger
- Department of Molecular Biology, University of Salzburg, Hellbrunner Strasse 34, 5020 Salzburg, Austria.
| | - Ariel Ruiz i Altaba
- Department of Genetic Medicine and Development, University of Geneva Medical School, 8242 CMU, 1 rue Michel Servet, CH-1211 Geneva, Switzerland.
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249
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Two histone/protein acetyltransferases, CBP and p300, are indispensable for Foxp3+ T-regulatory cell development and function. Mol Cell Biol 2014; 34:3993-4007. [PMID: 25154413 DOI: 10.1128/mcb.00919-14] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/20/2022] Open
Abstract
T-regulatory (Treg) cells are important to immune homeostasis, and Treg cell deficiency or dysfunction leads to autoimmune disease. A histone/protein acetyltransferase (HAT), p300, was recently found to be important for Treg function and stability, but further insights into the mechanisms by which p300 or other HATs affect Treg biology are needed. Here we show that CBP, a p300 paralog, is also important in controlling Treg function and stability. Thus, while mice with Treg-specific deletion of CBP or p300 developed minimal autoimmune disease, the combined deletion of CBP and p300 led to fatal autoimmunity by 3 to 4 weeks of age. The effects of CBP and p300 deletion on Treg development are dose dependent and involve multiple mechanisms. CBP and p300 cooperate with several key Treg transcription factors that act on the Foxp3 promoter to promote Foxp3 production. CBP and p300 also act on the Foxp3 conserved noncoding sequence 2 (CNS2) region to maintain Treg stability in inflammatory environments by regulating pCREB function and GATA3 expression, respectively. Lastly, CBP and p300 regulate the epigenetic status and function of Foxp3. Our findings provide insights into how HATs orchestrate multiple aspects of Treg development and function and identify overlapping but also discrete activities for p300 and CBP in control of Treg cells.
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Epigenetic mechanisms underlying the link between non-alcoholic fatty liver diseases and nutrition. Nutrients 2014; 6:3303-25. [PMID: 25195642 PMCID: PMC4145310 DOI: 10.3390/nu6083303] [Citation(s) in RCA: 82] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2014] [Revised: 08/06/2014] [Accepted: 08/07/2014] [Indexed: 12/12/2022] Open
Abstract
Non-alcoholic fatty liver disease (NAFLD) is defined as a pathologic accumulation of fat in the form of triglycerides (TG) in the liver (steatosis) that is not caused by alcohol. A subgroup of NAFLD patients shows liver cell injury and inflammation coupled with the excessive fat accumulation (steatohepatitis), which is referred to as non-alcoholic steatohepatitis (NASH). Patients with NASH may develop cirrhosis and hepatocellular carcinoma (HCC). NAFLD shares the key features of metabolic syndrome including obesity, hyperlipidemia, hypertension, and insulin resistance. The pathogenesis of NAFLD is multi-factorial, however the oxidative stress seems to plays a major role in the development and progression of the disease. The emerging field of epigenetics provides a new perspective on the pathogenesis of NAFLD. Epigenetics is an inheritable but reversible phenomenon that affects gene expression without altering the DNA sequence and refers to DNA methylation, histone modifications and microRNAs. Epigenetic manipulation through metabolic pathways such as one-carbon metabolism has been proposed as a promising approach to retard the progression of NAFLD. Investigating the epigenetic modifiers in NAFLD may also lead to the development of preventive or therapeutic strategies for NASH-associated complications.
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