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Schlag K, Steinhilber D, Karas M, Sorg BL. Analysis of proximal ALOX5 promoter binding proteins by quantitative proteomics. FEBS J 2020; 287:4481-4499. [PMID: 32096311 DOI: 10.1111/febs.15259] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2019] [Revised: 10/15/2019] [Accepted: 02/23/2020] [Indexed: 01/01/2023]
Abstract
5-Lipoxygenase (5-LO) is the initial enzyme in the biosynthesis of leukotrienes, which are mediators involved in pathophysiological conditions such as asthma and certain cancer types. Knowledge of proteins involved in 5-LO pathway regulation, including gene regulatory proteins, is needed to evaluate all options for therapeutic intervention in these diseases. Here, we present a mass spectrometric screening of ALOX5 promoter-interacting proteins, obtained by DNA pulldown and label-free quantitative mass spectrometry. Protein preparations from myeloid and B-lymphocytic cell lines were screened for promoter DNA interactors. Through statistical analysis, 66 proteins were identified as specific ALOX5 promotor binding proteins. Among those, the 15 most likely candidates for a prominent role in ALOX5 gene regulation are the known ALOX5 interactors Sp1 and Sp3, the related factor Sp2, two Krüppel-like factors (KLF13 and KLF16) and six other zinc finger proteins (MAZ, PRDM10, VEZF1, ZBTB7A, ZNF281 and ZNF579). Intriguingly, we also identified two helicases (BLM and DHX36) and the proteins hnRNPD and hnRNPK, which are, together with the protein MAZ, known to interact with DNA G-quadruplex structures. As G-quadruplexes are implicated in gene regulation, spectroscopic and antibody-based methods were used to confirm their presence within the GC-rich sequence of the ALOX5 promoter. In summary, we have systematically characterized the interactome of the ALOX5 promoter, identifying several zinc finger proteins as novel potential ALOX5 gene regulators. Further, we have shown that the ALOX5 promoter can form DNA G-quadruplex structures, which may play a functional role in ALOX5 gene regulation.
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Affiliation(s)
- Katharina Schlag
- Institute of Pharmaceutical Chemistry/ZAFES, Goethe-University, Frankfurt am Main, Germany
| | - Dieter Steinhilber
- Institute of Pharmaceutical Chemistry/ZAFES, Goethe-University, Frankfurt am Main, Germany
| | - Michael Karas
- Institute of Pharmaceutical Chemistry/ZAFES, Goethe-University, Frankfurt am Main, Germany
| | - Bernd L Sorg
- Institute of Pharmaceutical Chemistry/ZAFES, Goethe-University, Frankfurt am Main, Germany
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Poirier SJ, Boudreau LH, Flamand N, Surette ME. LPS induces ALOX5 promoter activation and 5-lipoxygenase expression in human monocytic cells. Prostaglandins Leukot Essent Fatty Acids 2020; 154:102078. [PMID: 32120263 DOI: 10.1016/j.plefa.2020.102078] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/08/2019] [Revised: 02/15/2020] [Accepted: 02/18/2020] [Indexed: 11/24/2022]
Abstract
5-lipoxygenase (5-LO), coded by the ALOX5 gene, is expressed in leukocytes and catalyzes the formation of leukotrienes, pro-inflammatory lipid mediators. Leukotrienes are central to immune responses, but are also involved in inflammatory disorders and 5-LO expression is associated with leukemia stem cell survival. It is therefore important to understand mechanisms that control 5-LO expression. This study investigated the control of 5-LO expression and leukotriene biosynthesis following the maturation of human monocytic cells. MonoMac-1 (MM1) and THP-1 cells were incubated for up to 72 h with or without LPS and TGF-β. LPS, but not TGF-β, increased CD14 expression in both MM1 and THP-1 cells. Incubation with LPS (100 ng/ml) and TGF-β (1 ng/ml) synergistically increased the capacity of MM1 cells to produce 5-LO products from undetectable levels to 40±5 pmol/106 cells. 5-LO product biosynthesis in THP-1 cells increased 25-fold. A synergistic effect of LPS and TGF-β was measured with increases in 5-LO mRNA of 54- and 13-fold in MM1 and THP-1 cells, respectively. 5-LO protein expression increased significantly in both MM1 and THP-1 cells. ALOX5 promoter activity was significantly elevated >2-fold in both cell lines following LPS treatment, but TGF-β was without effect. The main 5-LO products were cysteinyl-leukotrienes, however LPS and TGF-β did not impact on the capacity of the cells to metabolize leukotriene A4. Overall, this study demonstrates that receptor-mediated stimulation of MM1 and THP-1 cells by LPS is associated with increased 5-LO expression. This represents a new mechanism by which leukotriene biosynthesis can be modulated by pathological agents.
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Affiliation(s)
- Samuel J Poirier
- Département de chimie et biochimie, Université de Moncton, Moncton, NB, E1A 3E9, Canada; Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval, Département de médecine, Faculté de médecine, Université Laval, Québec City, QC, G1V 4G5, Canada
| | - Luc H Boudreau
- Département de chimie et biochimie, Université de Moncton, Moncton, NB, E1A 3E9, Canada
| | - Nicolas Flamand
- Centre de recherche de l'Institut universitaire de cardiologie et pneumologie de Québec-Université Laval, Département de médecine, Faculté de médecine, Université Laval, Québec City, QC, G1V 4G5, Canada
| | - Marc E Surette
- Département de chimie et biochimie, Université de Moncton, Moncton, NB, E1A 3E9, Canada.
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Häfner AK, Kahnt AS, Steinhilber D. Beyond leukotriene formation—The noncanonical functions of 5-lipoxygenase. Prostaglandins Other Lipid Mediat 2019; 142:24-32. [DOI: 10.1016/j.prostaglandins.2019.03.003] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/24/2019] [Revised: 03/14/2019] [Accepted: 03/25/2019] [Indexed: 01/17/2023]
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Transcriptional regulation of Translocator protein (18 kDa) (TSPO) in microglia requires Pu.1, Ap1 and Sp factors. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2018; 1861:1119-1133. [PMID: 30412797 DOI: 10.1016/j.bbagrm.2018.10.018] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 09/05/2018] [Revised: 10/12/2018] [Accepted: 10/31/2018] [Indexed: 11/21/2022]
Abstract
Mitochondrial Translocator protein (18 kDa) (TSPO) is strongly expressed in reactive microglia and serves as a therapeutic target for alleviation of neuronal degeneration. However, little is known about TSPO's transcriptional regulation in microglia. The aim of this study was to identify genetic elements and transcription factors required for basal and inducible TSPO expression in microglia. Murine Tspo promoter was cloned into the pGL4.10 luciferase vector and functionally characterized in BV-2 cells. Deletion mutagenesis indicated that -845 bases upstream were sufficient to reconstitute near maximal promoter activity in BV-2. Deletion of -593 to -520 sequences, which harbour an Ap1, Ets.2 and Nkx3.1 site which also serves as a non-canonical binding site for Sp1-family transcription factors, led to a dramatic decrease in both basal and LPS induced promoter activity. Further deletion of -168 to -39 sequences, which contains four GC boxes, also led to a significant decrease in promoter activity. Targeted mutations of Ap1, Ets.2, Nkx3.1/Sp1/3/4 and the GC boxes led to significant decreases in promoter activity. ChIP-qPCR revealed that Pu.1, Ap1, Stat3, Sp1, Sp3 and Sp4 bind to the endogenous Tspo promoter. Notably, binding of these factors, with the exception of Stat3, was significantly enhanced upon LPS treatment. RNAi silencing of Pu.1, cJun, cFos, Sp1, Sp3, Sp4 and Stat3 strongly lowered Tspo promoter activity while Ap1 silencing inhibited LPS induced increase in Tspo protein levels. These findings demonstrate that consensus binding sequences for Ap1, Ets.2, distal as well as proximal Sp1/3/4 sites regulate basal and LPS induced Tspo promoter activity in microglia.
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Hepp MI, Escobar D, Farkas C, Hermosilla VE, Álvarez C, Amigo R, Gutiérrez JL, Castro AF, Pincheira R. A Trichostatin A (TSA)/Sp1-mediated mechanism for the regulation of SALL2 tumor suppressor in Jurkat T cells. BIOCHIMICA ET BIOPHYSICA ACTA. GENE REGULATORY MECHANISMS 2018; 1861:S1874-9399(18)30028-2. [PMID: 29778644 DOI: 10.1016/j.bbagrm.2018.05.002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/22/2018] [Revised: 05/03/2018] [Accepted: 05/16/2018] [Indexed: 11/26/2022]
Abstract
SALL2 is a transcription factor involved in development and disease. Deregulation of SALL2 has been associated with cancer, suggesting that it plays a role in the disease. However, how SALL2 is regulated and why is deregulated in cancer remain poorly understood. We previously showed that the p53 tumor suppressor represses SALL2 under acute genotoxic stress. Here, we investigated the effect of Histone Deacetylase Inhibitor (HDACi) Trichostatin A (TSA), and involvement of Sp1 on expression and function of SALL2 in Jurkat T cells. We show that SALL2 mRNA and protein levels were enhanced under TSA treatment. Both, TSA and ectopic expression of Sp1 transactivated the SALL2 P2 promoter. This transactivation effect was blocked by the Sp1-binding inhibitor mithramycin A. Sp1 bound in vitro and in vivo to the proximal region of the P2 promoter. TSA induced Sp1 binding to the P2 promoter, which correlated with dynamic changes on H4 acetylation and concomitant recruitment of p300 or HDAC1 in a mutually exclusive manner. Our results suggest that TSA-induced Sp1-Lys703 acetylation contributes to the transcriptional activation of the P2 promoter. Finally, using a CRISPR/Cas9 SALL2-KO Jurkat-T cell model and gain of function experiments, we demonstrated that SALL2 upregulation is required for TSA-mediated cell death. Thus, our study identified Sp1 as a novel transcriptional regulator of SALL2, and proposes a novel epigenetic mechanism for SALL2 regulation in Jurkat-T cells. Altogether, our data support SALL2 function as a tumor suppressor, and SALL2 involvement in cell death response to HDACi.
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Affiliation(s)
- Matías I Hepp
- Departamento de Bioquímica y Biología Molecular, Facultad Cs. Biológicas, Universidad de Concepción, Chile.
| | - David Escobar
- Departamento de Bioquímica y Biología Molecular, Facultad Cs. Biológicas, Universidad de Concepción, Chile
| | - Carlos Farkas
- Departamento de Bioquímica y Biología Molecular, Facultad Cs. Biológicas, Universidad de Concepción, Chile
| | - Viviana E Hermosilla
- Departamento de Bioquímica y Biología Molecular, Facultad Cs. Biológicas, Universidad de Concepción, Chile
| | - Claudia Álvarez
- Departamento de Bioquímica y Biología Molecular, Facultad Cs. Biológicas, Universidad de Concepción, Chile
| | - Roberto Amigo
- Departamento de Bioquímica y Biología Molecular, Facultad Cs. Biológicas, Universidad de Concepción, Chile
| | - José L Gutiérrez
- Departamento de Bioquímica y Biología Molecular, Facultad Cs. Biológicas, Universidad de Concepción, Chile
| | - Ariel F Castro
- Departamento de Bioquímica y Biología Molecular, Facultad Cs. Biológicas, Universidad de Concepción, Chile
| | - Roxana Pincheira
- Departamento de Bioquímica y Biología Molecular, Facultad Cs. Biológicas, Universidad de Concepción, Chile.
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Saul MJ, Groher F, Hegewald AB, Müller-McNicoll M, Marschalek R, Suess B, Steinhilber D. TGFβ/SMAD signalling modulates MLL and MLL-AF4 mediated 5-lipoxygenase promoter activation. Prostaglandins Other Lipid Mediat 2017; 133:60-67. [DOI: 10.1016/j.prostaglandins.2017.07.006] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2017] [Revised: 06/28/2017] [Accepted: 07/31/2017] [Indexed: 01/11/2023]
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7
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Ahmad K, Scholz B, Capelo R, Schweighöfer I, Kahnt AS, Marschalek R, Steinhilber D. AF4 and AF4-MLL mediate transcriptional elongation of 5-lipoxygenase mRNA by 1, 25-dihydroxyvitamin D3. Oncotarget 2016; 6:25784-800. [PMID: 26329759 PMCID: PMC4694866 DOI: 10.18632/oncotarget.4703] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/09/2015] [Accepted: 07/10/2015] [Indexed: 12/22/2022] Open
Abstract
The human 5-lipoxygenase (5-LO), encoded by the ALOX5 gene, is the key enzyme in the formation of pro-inflammatory leukotrienes. ALOX5 gene transcription is strongly stimulated by calcitriol (1α, 25-dihydroxyvitamin D3) and TGFβ (transforming growth factor-β). Here, we investigated the influence of MLL (activator of transcript initiation), AF4 (activator of transcriptional elongation) as well as of the leukemogenic fusion proteins MLL-AF4 (ectopic activator of transcript initiation) and AF4-MLL (ectopic activator of transcriptional elongation) on calcitriol/TGFβ-dependent 5-LO transcript elongation. We present evidence that the AF4 complex directly interacts with the vitamin D receptor (VDR) and promotes calcitriol-dependent ALOX5 transcript elongation. Activation of transcript elongation was strongly enhanced by the AF4-MLL fusion protein but was sensitive to Flavopiridol. By contrast, MLL-AF4 displayed no effect on transcriptional elongation. Furthermore, HDAC class I inhibitors inhibited the ectopic effects caused by AF4-MLL on transcriptional elongation, suggesting that HDAC class I inhibitors are potential therapeutics for the treatment of t(4;11)(q21;q23) leukemia.
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Affiliation(s)
- Khalil Ahmad
- Institute of Pharmaceutical Chemistry / ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - Bastian Scholz
- Institute of Pharmaceutical Biology / ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - Ricardo Capelo
- Institute of Pharmaceutical Chemistry / ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - Ilona Schweighöfer
- Institute of Pharmaceutical Chemistry / ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - Astrid Stefanie Kahnt
- Institute of Pharmaceutical Chemistry / ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - Rolf Marschalek
- Institute of Pharmaceutical Biology / ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - Dieter Steinhilber
- Institute of Pharmaceutical Chemistry / ZAFES, Goethe University Frankfurt, Frankfurt, Germany
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8
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5-Lipoxygenase is a direct p53 target gene in humans. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2015; 1849:1003-16. [DOI: 10.1016/j.bbagrm.2015.06.004] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2015] [Revised: 05/19/2015] [Accepted: 06/07/2015] [Indexed: 11/18/2022]
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9
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Chueh AC, Tse JWT, Tögel L, Mariadason JM. Mechanisms of Histone Deacetylase Inhibitor-Regulated Gene Expression in Cancer Cells. Antioxid Redox Signal 2015; 23:66-84. [PMID: 24512308 PMCID: PMC4492771 DOI: 10.1089/ars.2014.5863] [Citation(s) in RCA: 50] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
SIGNIFICANCE Class I and II histone deacetylase inhibitors (HDACis) are approved for the treatment of cutaneous T-cell lymphoma and are undergoing clinical trials as single agents, and in combination, for other hematological and solid tumors. Understanding their mechanisms of action is essential for their more effective clinical use, and broadening their clinical potential. RECENT ADVANCES HDACi induce extensive transcriptional changes in tumor cells by activating and repressing similar numbers of genes. These transcriptional changes mediate, at least in part, HDACi-mediated growth inhibition, apoptosis, and differentiation. Here, we highlight two fundamental mechanisms by which HDACi regulate gene expression—histone and transcription factor acetylation. We also review the transcriptional responses invoked by HDACi, and compare these effects within and across tumor types. CRITICAL ISSUES The mechanistic basis for how HDACi activate, and in particular repress gene expression, is not well understood. In addition, whether subsets of genes are reproducibly regulated by these agents both within and across tumor types has not been systematically addressed. A detailed understanding of the transcriptional changes elicited by HDACi in various tumor types, and the mechanistic basis for these effects, may provide insights into the specificity of these drugs for transformed cells and specific tumor types. FUTURE DIRECTIONS Understanding the mechanisms by which HDACi regulate gene expression and an appreciation of their transcriptional targets could facilitate the ongoing clinical development of these emerging therapeutics. In particular, this knowledge could inform the design of rational drug combinations involving HDACi, and facilitate the identification of mechanism-based biomarkers of response.
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Affiliation(s)
- Anderly C Chueh
- Ludwig Institute for Cancer Research , Olivia Newton John Cancer and Wellness Centre, Austin Health, Melbourne, Australia
| | - Janson W T Tse
- Ludwig Institute for Cancer Research , Olivia Newton John Cancer and Wellness Centre, Austin Health, Melbourne, Australia
| | - Lars Tögel
- Ludwig Institute for Cancer Research , Olivia Newton John Cancer and Wellness Centre, Austin Health, Melbourne, Australia
| | - John M Mariadason
- Ludwig Institute for Cancer Research , Olivia Newton John Cancer and Wellness Centre, Austin Health, Melbourne, Australia
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Ahmad K, Katryniok C, Scholz B, Merkens J, Löscher D, Marschalek R, Steinhilber D. Inhibition of class I HDACs abrogates the dominant effect of MLL-AF4 by activation of wild-type MLL. Oncogenesis 2014; 3:e127. [PMID: 25402609 PMCID: PMC4259963 DOI: 10.1038/oncsis.2014.39] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2014] [Revised: 09/14/2014] [Accepted: 09/30/2014] [Indexed: 12/15/2022] Open
Abstract
The ALOX5 gene encodes 5-lipoxygenase (5-LO), a key enzyme of inflammatory reactions, which is transcriptionally activated by trichostatin A (TSA). Physiologically, 5-LO expression is induced by calcitriol and/or transforming growth factor-β. Regulation of 5-LO mRNA involves promoter activation and elongation control within the 3'-portion of the ALOX5 gene. Here we focused on the ALOX5 promoter region. Transcriptional initiation was associated with an increase in histone H3 lysine 4 trimethylation in a TSA-inducible manner. Therefore, we investigated the effects of the MLL (mixed lineage leukemia) protein and its derivatives, MLL-AF4 and AF4-MLL, respectively. MLL-AF4 was able to enhance ALOX5 promoter activity by 47-fold, which was further stimulated when either vitamin D receptor and retinoid X receptor or SMAD3/SMAD4 were co-transfected. In addition, we investigated several histone deacetylase inhibitors (HDACi) in combination with gene knockdown experiments (HDAC1-3, MLL). We were able to demonstrate that a combined inhibition of HDAC1-3 induces ALOX5 promoter activity in an MLL-dependent manner. Surprisingly, a constitutive activation of ALOX5 by MLL-AF4 was inhibited by class I HDAC inhibitors, by relieving inhibitory functions deriving from MLL.Conversely, a knockdown of MLL increased the effects mediated by MLL-AF4. Thus, HDACi treatment seems to switch 'inactive MLL' into 'active MLL' and overwrites the dominant functions deriving from MLL-AF4.
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Affiliation(s)
- K Ahmad
- Institute of Pharmaceutical Chemistry/ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - C Katryniok
- Institute of Pharmaceutical Chemistry/ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - B Scholz
- Institute of Pharmaceutical Biology/ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - J Merkens
- Institute of Pharmaceutical Biology/ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - D Löscher
- Institute of Pharmaceutical Biology/ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - R Marschalek
- Institute of Pharmaceutical Biology/ZAFES, Goethe University Frankfurt, Frankfurt, Germany
| | - D Steinhilber
- Institute of Pharmaceutical Chemistry/ZAFES, Goethe University Frankfurt, Frankfurt, Germany
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Ling CS, Yin KB, Cun STW, Ling FL. Expression profiling of choline and ethanolamine kinases in MCF7, HCT116 and HepG2 cells, and the transcriptional regulation by epigenetic modification. Mol Med Rep 2014; 11:611-8. [PMID: 25333818 DOI: 10.3892/mmr.2014.2707] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/10/2013] [Accepted: 09/04/2014] [Indexed: 11/06/2022] Open
Abstract
The function of choline kinase (CK) and ethanolamine kinase (EK) is to catalyse the phosphorylation of choline and ethanolamine, respectively, in order to yield phosphocholine (PCho) and phosphoethanolamine (PEtn). A high expression level of PCho, due to elevated CK activity, has previously been associated with malignant transformation. In the present study, a quantitative polymerase chain reaction was performed to determine the mRNA expression profiles of ck and ek mRNA variants in MCF7 breast, HCT116 colon and HepG2 liver cancer cells. The ck and ek mRNA expression profiles showed that total ckα was expressed most abundantly in the HepG2 cells. The HCT116 cells exhibited the highest ckβ and ek1 mRNA expression levels, whereas the highest ek2α mRNA expression levels were detected in the MCF7 cells. The ckβ variant had higher mRNA expression levels, as compared with total ckα, in both the MCF7 and HCT116 cells. Relatively low ek1 mRNA expression levels were detected, as compared with ek2α in the MCF7 cells; however, this was not observed in the HCT116 and HepG2 cells. Notably, the mRNA expression levels of ckα2 were markedly low, as compared with ckα1, in all three cancer cell lines. The effects of epigenetic modification on ck and ek mRNA expression, by treatment of the cells with the histone deacetylase inhibitor trichostatin A (TSA), were also investigated. The results of the present study showed that the mRNA expression levels of ckα, ckβ and ek2α were affected by TSA. An increase >8-fold was observed in ek2α mRNA expression upon treatment with TSA, in a concentration- and time-dependent manner. In conclusion, the levels of ck and ek transcript variants in the three cancer cell lines were varied. The effects of TSA treatment on the mRNA expression levels of ck and ek imply that ck and ek mRNA expression may be regulated by epigenetic modification.
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Affiliation(s)
- Chua Siang Ling
- School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia
| | - Khoo Boon Yin
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Penang 11800, Malaysia
| | - See Too Wei Cun
- School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia
| | - Few Ling Ling
- School of Health Sciences, Universiti Sains Malaysia, Kubang Kerian, Kelantan 16150, Malaysia
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Phosphorylation mimicking mutations of ALOX5 orthologs of different vertebrates do not alter reaction specificities of the enzymes. Biochim Biophys Acta Mol Cell Biol Lipids 2014; 1842:1460-6. [DOI: 10.1016/j.bbalip.2014.07.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2014] [Revised: 06/19/2014] [Accepted: 07/07/2014] [Indexed: 12/19/2022]
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13
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Wang JX, Yi Y, Li YW, Cai XY, He HW, Ni XC, Zhou J, Cheng YF, Jin JJ, Fan J, Qiu SJ. Down-regulation of sirtuin 3 is associated with poor prognosis in hepatocellular carcinoma after resection. BMC Cancer 2014; 14:297. [PMID: 24774224 PMCID: PMC4021365 DOI: 10.1186/1471-2407-14-297] [Citation(s) in RCA: 34] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Accepted: 04/17/2014] [Indexed: 01/13/2023] Open
Abstract
Background Sirtuin 3 (Sirt3), one of the seven Sirtuins family members, plays critical roles in the progression of multiple cancer types. However, its role in the prognosis of hepatocellular carcinoma (HCC) has not yet been investigated systematically. Methods The correlation of Sirtuins expression with prognosis of HCC was determined by immunohistochemistry (IHC) in a large HCC patient cohort (n = 342). Expression of Sirt3 in tumoral and peritumoral tissues of HCC patients were further determined by western blotting (WB). Results IHC and WB studies both showed a decreased expression of Sirt3 in tumoral tissues compared with peritumoral tissues (P = 0.003 for IHC, P = 0.0042 for WB). Decreased expression of Sirt3 in both tumoral and peritumoral tissues was associated with increased recurrence probability and decreased overall survival rate by univariate analyses (intratumoral Sirt3: P = 0.011 for TTR, P = 0.001 for OS; peritumoral Sirt3: P = 0.017 for TTR, P = 0.023 for OS), the prognostic value was strengthened by multivariate analyses (intratumoral Sirt3: P = 0.031 for TTR, P = 0.001 for OS; peritumoral Sirt3: P = 0.047 for TTR, P = 0.031 for OS). Intratumoral Sirt3 also showed a favorable prognostic value in patients with BCLC stage A (TTR, P = 0.011; OS, P < 0.001). In addition, we found that IHC studies of other sirtuin members showed a decreased expression of Sirt2, Sirt4 and Sirt5 and an increased expression of Sirt1, Sirt6 and Sirt7 in intratumoral tissues compared with peritumoral tissues. In contrast to Sirt3, other members did not showed a remarkable correlation with HCC prognosis. Conclusions Down-regulation of intratumoral and peritumoral Sirt3 were both associated with poor outcome in HCC, moreover, intratumoral Sirt3 was a favorable prognostic predictor in early stage patients.
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Affiliation(s)
| | | | | | | | | | | | | | | | | | | | - Shuang-Jian Qiu
- Liver Cancer Institute, Zhongshan Hospital, Fudan University, Key Laboratory for Carcinogenesis & Cancer Invasion, The Chinese Ministry of Education, Shanghai, People's Republic of China.
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14
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Potter JJ, Liu X, Koteish A, Mezey E. 1,25-dihydroxyvitamin D3 and its nuclear receptor repress human α1 (I) collagen expression and type I collagen formation. Liver Int 2013; 33:677-86. [PMID: 23413886 PMCID: PMC3707129 DOI: 10.1111/liv.12122] [Citation(s) in RCA: 45] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/12/2012] [Accepted: 12/24/2012] [Indexed: 12/12/2022]
Abstract
BACKGROUND Vitamin D deficiency is common in chronic liver disease particularly in those with severe liver fibrosis. AIMS To determine the effect of 1,25-dihydroxyvitamin D3 (1,25-(OH)2 D3 ) on the human α(1) (I) collagen promoter and collagen formation by human stellate LX-2 cells and the mechanism of the effect of the vitamin D receptor (VDR) on the promoter. METHODS Type I collagen was assessed by measurements of collagen mRNA and collagen protein and by transfection experiments. Binding of VDR to the α(1) (I) collagen promoter was determined by EMSA and ChIP assays. RESULTS 1,25-(OH)2 D3 decreased human α(1) (I) collagen mRNA and protein and the secretion of type I collagen by stellate cells after exposure to TGFβ1. Furthermore, 1,25-(OH)2 D3 inhibited TGFβ1-induced activation of the α(1) (I) collagen promoter in transfected LX-2 cells. The effect of 1,25-(OH)2 D3 is mediated by the VDR, which binds at a proximal Sp1 site and also at a newly identified distal site on the collagen promoter. A VDR expression vector reduced the activities of the collagen promoter in transfected LX-2 cells. CONCLUSIONS 1,25-(OH)2 D3 inhibits type I collagen formation in human stellate cells. The effect of 1,25-(OH)2 D3 is mediated by its receptor which binds at a proximal Sp1.1 site and at a newly identified distal site on the collagen promoter. Correction of vitamin D deficiency in patients with chronic liver disease is a potential therapy to inhibit progression of fibrosis.
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Affiliation(s)
- James J Potter
- Department of Medicine, The Johns Hopkins University School of Medicine, Baltimore, MD, USA
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Azakie A, Fineman J, He Y. Differential responses of the right ventricle to abnormal loading conditions in vivo: possible pathophysiologic mechanisms. J Thorac Cardiovasc Surg 2013; 145:1335-44. [PMID: 23434296 DOI: 10.1016/j.jtcvs.2013.01.016] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2012] [Revised: 12/13/2012] [Accepted: 01/11/2013] [Indexed: 11/17/2022]
Abstract
OBJECTIVE The right ventricle (RV) demonstrates differential adaptations in response to pressure versus volume loading, a phenomenon that may be important in the management of children and adults with congenital heart disease (CHD). The purpose of this study is to elucidate possible transcriptional mechanisms of the RV response to pressure versus volume loading in vivo. METHODS Fetal lambs had aortopulmonary shunting or pulmonary artery (PA) banding. Four weeks after spontaneous delivery, ovine hearts were evaluated for hemodynamic changes and changes in expression of sarcomeric gene proteins and transcriptional factors. Western blot densitometry and chromatin immunoprecipitation were applied using standard techniques. Transactivation assays were performed using transient transfections in Schneider's Drosophila line 2 cells in culture. RESULTS After PA banding, the RV pressure increased from 36 ± 4 mm Hg (n = 4) to 96 ± 8 mm Hg (n = 4, P < .05). The RVs of shunted and banded animals showed significant increases in the expression levels and promoter binding of activators myocyte enhancer factor 2, GATA-4, Nkx2.5, transcriptional enhancer factor 1, and specificity protein (Sp) 1. The transcriptional repressor Sp3 was downregulated in shunted animals, but its expression was increased paradoxically in the RV of the PA band group. Immunoprecipitation of Sp3 showed posttranslational modification to the acetylated isoform. In transient transfections of Schneider's Drosophila line 2 cells, acetylation of Sp3 converted it from a transcriptional repressor to an activator. CONCLUSIONS Posttranslational modifications of the transcriptional repressor Sp3, by acetylation, may be an important mechanism in the differential response of the RV to abnormal loading conditions. Sp3 may serve as a biomarker for RV failure for various heart defects in children and adults with CHD. These findings may have therapeutic implications in the management of right heart failure.
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MESH Headings
- Acetylation
- Animals
- Binding Sites
- Blotting, Western
- Cell Line
- Chromatin Immunoprecipitation
- Disease Models, Animal
- Female
- GATA4 Transcription Factor/genetics
- GATA4 Transcription Factor/metabolism
- Gene Expression Regulation
- Gestational Age
- Heart Ventricles/metabolism
- Heart Ventricles/physiopathology
- Hemodynamics
- Hypertrophy, Right Ventricular/genetics
- Hypertrophy, Right Ventricular/metabolism
- Hypertrophy, Right Ventricular/physiopathology
- MEF2 Transcription Factors
- Myocardium/metabolism
- Myogenic Regulatory Factors/genetics
- Myogenic Regulatory Factors/metabolism
- Pregnancy
- Promoter Regions, Genetic
- Protein Processing, Post-Translational
- Pulmonary Artery/physiopathology
- Pulmonary Artery/surgery
- Sheep
- Sp1 Transcription Factor/genetics
- Sp1 Transcription Factor/metabolism
- Sp3 Transcription Factor/genetics
- Sp3 Transcription Factor/metabolism
- Time Factors
- Transcriptional Activation
- Transfection
- Ventricular Dysfunction, Right/genetics
- Ventricular Dysfunction, Right/metabolism
- Ventricular Dysfunction, Right/physiopathology
- Ventricular Function, Right/genetics
- Ventricular Pressure
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Affiliation(s)
- Anthony Azakie
- Department of Surgery, University of California at San Francisco, San Francisco, CA 94143, USA.
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16
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Pufahl L, Katryniok C, Schnur N, Sorg BL, Metzner J, Grez M, Steinhilber D. Trichostatin A induces 5-lipoxygenase promoter activity and mRNA expression via inhibition of histone deacetylase 2 and 3. J Cell Mol Med 2012; 16:1461-73. [PMID: 21883892 PMCID: PMC3823215 DOI: 10.1111/j.1582-4934.2011.01420.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022] Open
Abstract
The 5-lipoxygenase (5-LO) is the key enzyme in the formation of leukotrienes. We have previously shown that the histone deacetylase (HDAC) inhibitor trichostatin A (TSA) activates 5-LO transcription via recruitment of Sp1, Sp3 and RNA polymerase II to the proximal promoter. To identify the HDACs involved in the regulation of 5-LO promoter activity isoform-specific HDAC inhibitors were applied. 5-LO promoter activity and mRNA expression were up-regulated by the class I HDAC inhibitors apicidin and MS-275 but not by class II inhibitors. Knockdown of HDAC 1, 2 and 3 revealed that HDAC2 and HDAC3 but not HDAC1 is involved in the up-regulation of 5-LO mRNA expression. To analyse the chromatin modifications at the 5-LO promoter associated with HDAC inhibition, the time course of 5-LO mRNA induction by trichostatin A was investigated and the concomitant changes in histone modifications at the 5-LO promoter in HL-60, U937 and Mono Mac6 cells were determined. Chromatin immunoprecipitation analysis revealed that trichostatin A increases acetylation of histones H3 and H4 at the 5-LO core promoter in HL-60 and U937 cells whereas no significant changes were observed in Mono Mac6 cells. The appearance of H3 and H4 acetylation preceded the 5-LO mRNA induction whereas in all three cell lines, induction of 5-LO mRNA expression correlated with histone H3 lysine 4 trimethylation (H3K4me3), a marker for transcriptional activity of gene promoters.
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Affiliation(s)
- Laura Pufahl
- Institute of Pharmaceutical Chemistry/ZAFES, Goethe University Frankfurt, Frankfurt, Germany
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17
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Kou XX, Hao T, Meng Z, Zhou YH, Gan YH. Acetylated Sp1 inhibits PTEN expression through binding to PTEN core promoter and recruitment of HDAC1 and promotes cancer cell migration and invasion. Carcinogenesis 2012; 34:58-67. [PMID: 23104175 DOI: 10.1093/carcin/bgs336] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
Specificity protein 1 (Sp1) is often overexpressed in cancer cells. Its binding sites are known to exist in the phosphatase and tension homolog deleted on chromosome 10 (PTEN) promoter. In this study, we hypothesized that Sp1 negatively regulates PTEN expression. We used several cell lines to determine the effects of Sp1. The results showed that Sp1 overexpression inhibited the expression and promoter activity of PTEN and correspondingly upregulated AKT phosphorylation, whereas Sp1 knockdown upregulated the expression and promoter ability of PTEN and downregulated AKT phosphorylation. Moreover, a series of deletion and site-directed mutations of the PTEN promoter indicated that Sp1 can inhibit PTEN promoter activity through a specific Sp1-binding site at the PTEN core promoter in vivo. Meanwhile, non-acetylated Sp1, with its loss of DNA binding activity, failed to inhibit the expression and promoter activity of PTEN. Histone deacetylase 1 was necessary for Sp1 to inhibit PTEN expression. The inverse expression of Sp1 and PTEN was found in tongue cancer cells and salivary adenoid cystic cancer (SACC)-LM cells (possessing higher potential for lung metastasis than SACC-83) as compared with that in adjacent normal tissue and SACC-83 cells, respectively. Sp1 knockdown decreased the migration and invasion of SACC-LM cells, whereas Sp1 overexpression increased the migration and invasion of SACC-83 cells. Overall, these results suggest that Sp1 is involved in the development and invasiveness of cancer through inhibition of PTEN.
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Affiliation(s)
- Xiao-Xing Kou
- Department of Orthodontics, Peking University School and Hospital of Stomatology, 22 Zhongguancun Avenue South, Haidian District, Beijing 100081, China
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18
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Seuter S, Heikkinen S, Carlberg C. Chromatin acetylation at transcription start sites and vitamin D receptor binding regions relates to effects of 1α,25-dihydroxyvitamin D3 and histone deacetylase inhibitors on gene expression. Nucleic Acids Res 2012; 41:110-24. [PMID: 23093607 PMCID: PMC3592476 DOI: 10.1093/nar/gks959] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
The nuclear hormone 1α,25-dihydroxyvitamin D3 (1α,25(OH)2D3 or 1,25D) regulates its target genes via activation of the transcription factor vitamin D receptor (VDR) far more specifically than the chromatin modifier trichostatin A (TsA) via its inhibitory action on histone deacetylases. We selected the thrombomodulin gene locus with its complex pattern of five VDR binding sites and multiple histone acetylation and open chromatin regions as an example to investigate together with a number of reference genes, the primary transcriptional responses to 1α,25(OH)2D3 and TsA. Transcriptome-wide, 18.4% of all expressed genes are either up-or down-regulated already after a 90 min TsA treatment; their response pattern to 1α,25(OH)2D3 and TsA sorts them into at least six classes. TsA stimulates a far higher number of genes than 1α,25(OH)2D3 and dominates the outcome of combined treatments. However, 200 TsA target genes can be modulated by 1α,25(OH)2D3 and more than 1000 genes respond only when treated with both compounds. The genomic view on the genes suggests that the degree of acetylation at transcription start sites and VDR binding regions may determine the effect of TsA on mRNA expression and its interference with 1α,25(OH)2D3. Our findings hold true also for other HDAC inhibitors and may have implications on dual therapies using chromatin modifiers and nuclear receptor ligands.
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Affiliation(s)
| | | | - Carsten Carlberg
- *To whom correspondence should be addressed. Tel: +358 40 355 3062; Fax: +358 17 281 1510;
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19
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Diao B, Liu Y, Zhang Y, Liu Q, Lu WJ, Xu G. Functional network analysis with the subcellular location and gene ontology information in human allergic asthma. Genet Test Mol Biomarkers 2012; 16:1287-92. [PMID: 23057572 DOI: 10.1089/gtmb.2011.0325] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
Abstract
Asthma is a chronic inflammatory disease characterized by airway hyperresponsiveness, tissue remodeling, and airflow obstruction. The pathogenesis of asthma is only partly understood, and there is an urgent need for improved therapeutic strategies for this disease. The protein-protein interaction (PPI) network has considerable promise as a tool for discovery of novel asthma therapeutic targets and their relationship. Among the genes that have been identified by PPI studies, APP, CDKN1B, and SP3 displayed up-regulated expression. Further study depicted that CDKN1B localized in the nucleus or cytoplasm could interact with GRB2 and CASP8, but SP3 localized in the nucleus could interact with histone deacetylase 1, SP1, and E2F1. We anticipate that these types of analyses will provide considerable insight into asthma pathogenesis and will provide a wealth of new molecules for downstream analyses.
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Affiliation(s)
- Bo Diao
- Wuhan General Hospital Guangzhou Military Region, Wuhan, China
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20
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Yang PM, Lin PJ, Chen CC. CD1d induction in solid tumor cells by histone deacetylase inhibitors through inhibition of HDAC1/2 and activation of Sp1. Epigenetics 2012; 7:390-9. [PMID: 22419072 DOI: 10.4161/epi.19373] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
CD1d is a MHC class-like molecule that presents glycolipids to natural killer T (NKT) cells, then regulates innate and adaptive immunity. The regulation of CD1d gene expression in solid tumors is still largely unknown. Gene expression can be epigenetically regulated by DNA methylation and histone acetylation. We found that histone deacetylase inhibitors, trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA), induced CD1d gene expression in human (A549 and NCI-H292) and mouse (TC-1 and B16/F0) cancer cells. Simultaneous knockdown of HDAC1 and 2 induced CD1d gene expression. Sp1 inhibitor mitramycin A (MTM) blocked TSA- and SAHA-induced CD1d mRNA expression and Sp1 luciferase activity. Co-transfection of GAL4-Sp1 and Fc-luciferase reporters demonstrated that TSA and SAHA induced Sp1 luciferase reporter activity by enhancing Sp1 transactivation activity. The binding of Sp1 to CD1d promoter and histone H3 acetylation on Sp1 sites were increased by TSA and SAHA. These results indicate that TSA and SAHA could up-regulate CD1d expression in tumor cells through inhibition of HDAC1/2 and activation of Sp1.
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Affiliation(s)
- Pei-Ming Yang
- Department of Pharmacology, College of Medicine, National Taiwan University, Taipei, Taiwan
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21
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Simiele F, Recchiuti A, Mattoscio D, De Luca A, Cianci E, Franchi S, Gatta V, Parolari A, Werba JP, Camera M, Favaloro B, Romano M. Transcriptional regulation of the human FPR2/ALX gene: evidence of a heritable genetic variant that impairs promoter activity. FASEB J 2011; 26:1323-33. [PMID: 22131270 DOI: 10.1096/fj.11-198069] [Citation(s) in RCA: 49] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023]
Abstract
Lipoxin (LX) A(4,) a main endogenous stop-signal of inflammation, activates the G-protein-coupled receptor FPR2/ALX, which triggers potent anti-inflammatory signaling in vivo. Thus, the regulation of FPR2/ALX expression may have pathophysiological and therapeutic relevance. Here, we mapped a nucleotide sequence with strong FPR2/ALX promoter activity. Chromatin immunoprecipitation revealed specificity protein 1 (Sp1) binding to the core promoter. Site-directed mutagenesis of the Sp1 cis-acting element and Sp1 overexpression established that this transcription factor is key for maximal promoter activity, which is instead suppressed by DNA methylation. LXA(4) enhanced FPR2/ALX promoter activity (+74%) and mRNA expression (+87.5%) in MDA-MB231 cells. A single nucleotide mutation (A/G) was detected in the core promoter of one subject with history of cardiovascular disease and of his two daughters. This mutation reduced by ∼35-90% the promoter activity in vitro. Moreover, neutrophils from individuals carrying the A/G variant displayed ∼10- and 3-fold reduction in FPR2/ALX mRNA and protein, respectively, compared with cells from their relatives or healthy volunteers expressing the wild-type allele. These results uncover FPR2/ALX transcriptional regulation and provide the first evidence of mutations that affect FPR2/ALX transcription, thus opening new opportunities for the understanding of the LXA(4)-FPR2/ALX axis in human disease.
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Affiliation(s)
- Felice Simiele
- Department of Biomedical Sciences, Center of Excellence on Aging, Ce.S.I., G. d'Annunzio University Foundation, Via Colle dell'Ara, 66013 Chieti, Italy
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22
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Bian Y, Zhou W, Zhao Y, Li X, Geng W, Hao R, Yang Q, Huang W. High-dose siRNAs upregulate mouse Eri-1 at both transcription and posttranscription levels. PLoS One 2011; 6:e26466. [PMID: 22039495 PMCID: PMC3198429 DOI: 10.1371/journal.pone.0026466] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2011] [Accepted: 09/27/2011] [Indexed: 01/05/2023] Open
Abstract
The eri-1 gene encodes a 3′ exonuclease that can negatively regulate RNA interference via siRNase activity. High-dose siRNAs (hd-siRNAs) can enhance Eri-1 expression, which in return degrade siRNAs and greatly reduces RNAi efficiency. Here we report that hd-siRNAs induce mouse Eri-1 (meri-1) expression through the recruitment of Sp1, Ets-1, and STAT3 to the meri-1 promoter and the formation of an Sp1-Ets-1-STAT3 complex. In addition, hd-siRNAs also abolish the 3′ untranslated region (UTR) mediated posttranscriptional repression of meri-1. Our findings demonstrate the molecular mechanism underlying the upregulation of meri-1 by hd-siRNA.
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Affiliation(s)
- Yingnan Bian
- Department of Biochemistry, School of Life Science, Fudan University, Shanghai, China
| | - Wei Zhou
- Department of Biochemistry, School of Life Science, Fudan University, Shanghai, China
| | - Yingchun Zhao
- Department of Biochemistry, School of Life Science, Fudan University, Shanghai, China
| | - Xiaoping Li
- Department of Biochemistry, School of Life Science, Fudan University, Shanghai, China
| | - Wei Geng
- Department of Biochemistry, School of Life Science, Fudan University, Shanghai, China
| | - Ruixin Hao
- Department of Biochemistry, School of Life Science, Fudan University, Shanghai, China
| | - Qing Yang
- Department of Biochemistry, School of Life Science, Fudan University, Shanghai, China
| | - Weida Huang
- Department of Biochemistry, School of Life Science, Fudan University, Shanghai, China
- Laboratory for Synthetic Biology, Centers for Nano-Medicine, Shanghai Advanced Research Institute, Chinese Academy Sciences, Pudong, Shanghai, China
- * E-mail:
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23
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Lee SJ, Kim CE, Seo KW, Kim CD. HNE-induced 5-LO expression is regulated by NF-{kappa}B/ERK and Sp1/p38 MAPK pathways via EGF receptor in murine macrophages. Cardiovasc Res 2010; 88:352-9. [PMID: 20554538 DOI: 10.1093/cvr/cvq194] [Citation(s) in RCA: 222] [Impact Index Per Article: 15.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
AIMS 5-Lipoxygenase (5-LO) has been suggested to be a modulator of atherosclerotic plaque instability and co-exists with 4-hydroxynonenal (HNE) in macrophages in atherosclerotic lesions. To determine the potential role for HNE in 5-LO expression, the molecular mechanisms of 5-LO expression were evaluated in HNE-stimulated macrophages. METHODS AND RESULTS A genomic sequence of the promoter 2.0 kb upstream of the transcription initiation site was amplified, and a series of sequentially deleted fragments were then fused to a luciferase reporter gene. The promoter region 213 bp upstream of the transcription start site was responsible for the HNE-enhanced transcriptional activity of 5-LO. Site-directed mutagenesis of this region showed that the transcription factors, including stimulating protein 1 (Sp1) and nuclear factor-κB (NF-κB), were associated with up-regulation of HNE-induced 5-LO transcription. Moreover, the role of Sp1 and NF-κB in HNE-induced 5-LO expression was confirmed by siRNA knockdown of Sp1 and NF-κB. The HNE-enhanced Sp1 and NF-κB activities were attenuated by SB203580, a p38 mitogen-activated protein kinase (MAPK) inhibitor, and PD98059, an extracellular signal-regulated kinase (ERK) inhibitor, respectively. In addition, the HNE-enhanced phosphorylation of p38 MAPK and ERK was inhibited by AG1478, an epidermal growth factor receptor (EGFR) antagonist, but not by AG1295, a platelet-derived growth factor receptor (PDGFR) antagonist. CONCLUSION 5-LO expression by HNE was regulated at the transcriptional level by the EGFR-mediated activation of Sp1/p38 MAPK and NF-κB/ERK pathways in macrophages, which may lead to the development of therapeutic interventions for regulating 5-LO expression in atherosclerosis.
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Affiliation(s)
- Seung J Lee
- Department of Pharmacology and BK21 Medical Science Education Center, School of Medicine, Pusan National University, Yangsan, Gyeongnam 626-870, Korea
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24
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Wang W, Di X, Torti SV, Torti FM. Ferritin H induction by histone deacetylase inhibitors. Biochem Pharmacol 2010; 80:316-24. [PMID: 20385107 DOI: 10.1016/j.bcp.2010.04.008] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2010] [Revised: 04/01/2010] [Accepted: 04/02/2010] [Indexed: 12/27/2022]
Abstract
Because both iron deficiency and iron excess are deleterious to normal cell function, the intracellular level of iron must be tightly controlled. Ferritin, an iron binding protein, regulates iron balance by storing iron in a bioavailable but nontoxic form. Ferritin protein comprises two subunits: ferritin H, which contains ferroxidase activity, and ferritin L. Here we demonstrate that ferritin H mRNA and protein are induced by histone deacetylase inhibitors (HDAC inhibitors), a promising class of anti-cancer drugs, in cultured human cancer cells. Deletion analysis and EMSA assays reveal that the induction of ferritin H occurs at a transcriptional level via Sp1 and NF-Y binding sites near the transcriptional start site of the human ferritin H promoter. Classically, HDAC inhibitors modulate gene expression by increasing histone acetylation. However, ChIP assays demonstrate that HDAC inhibitors induce ferritin H transcription by increasing NF-Y binding to the ferritin H promoter without changes in histone acetylation. These results identify ferritin H as a new target of HDAC inhibitors, and recruitment of NF-Y as a novel mechanism of action of HDAC inhibitors.
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Affiliation(s)
- Wei Wang
- Department of Cancer Biology, Wake Forest University School of Medicine, Winston-Salem, NC 27157, United States
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25
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Identification of trichostatin A as a novel transcriptional up-regulator of scavenger receptor BI both in HepG2 and RAW 264.7 cells. Atherosclerosis 2009; 204:127-35. [DOI: 10.1016/j.atherosclerosis.2008.08.041] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/08/2008] [Revised: 08/23/2008] [Accepted: 08/26/2008] [Indexed: 12/17/2022]
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Abstract
5-lipoxygenase (5-LO) catalyzes two steps in biosynthesis of leukotrienes (LTs), a group of lipid mediators of inflammation derived from arachidonic acid (AA). LT antagonists are used in treatment of asthma; more recently a potential role also in atherosclerosis has raised considerable interest. Furthermore, possible effects of 5-LO metabolites in relation to tumorigenesis have emerged. Thus, an understanding of the biochemistry of this lipoxygenase has potential implications for treatment of various diseases.
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Affiliation(s)
- Olof Rådmark
- Department Medical Biochemistry and Biophysics, Division of Physiological Chemistry II, Karolinska Institutet, S-17177 Stockholm, Sweden
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27
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Effects of trichostatin A on neuronal mu-opioid receptor gene expression. Brain Res 2008; 1246:1-10. [PMID: 18950606 DOI: 10.1016/j.brainres.2008.09.083] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2008] [Revised: 09/17/2008] [Accepted: 09/19/2008] [Indexed: 11/21/2022]
Abstract
In this study, we determined the effects of a histone deacetylase (HDAC) inhibitor, trichostatin A (TSA), on neuronal mu-opioid receptor (MOR) gene expression using human neuronal NMB cells, endogenously expressing MOR. Recruitment of two classes of HDAC, HDAC1 and HDAC2, to MOR promoter region in situ was detected via chromatin immunoprecipitation (ChIP) analysis with NMB cells. Functional analysis using the luciferase reporter gene system showed that TSA induced an approximately 3-fold increase of the promoter activity as compared to the vehicle treated group. Mutation analysis demonstrated that TSA response was mediated by both dsDNA (Sp1/Sp3 binding site) and ssDNA (PolyC binding protein1, PCBP, binding site) elements located in mouse MOR proximal core promoter region, further suggesting the functional importance of this cis-element, which shows high sequence homology between human and mouse MOR genes. ChIP analysis further suggested that TSA enhanced the recruitment of Sp1/Sp3 and PCBP to the promoter region, whereas no significant changes of total proteins were observed in response to TSA using Western blot analysis. Moreover, confocal images showed TSA-induced nuclear hot spots of endogenous PCBP in neuronal cells, whereas no obvious nuclear PCBP hotspot was observed in vehicle treated cells. Taken together, these results suggested that TSA enhanced neuronal MOR gene expression at the transcriptional level. RT-PCR analysis further revealed that TSA also decreased the steady-state level of MOR mRNA in a time-dependent manner by enhancing its instability. Thus, data suggest that TSA, an epigenetic regulator, affects neuronal MOR gene expression at both transcriptional and post-transcriptional levels.
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