Evidence for a link between histone deacetylation and Ca2+ homoeostasis in sphingosine-1-phosphate lyase-deficient fibroblasts

2012 ◽  
Vol 447 (3) ◽  
pp. 457-464 ◽  
Author(s):  
Katja Ihlefeld ◽  
Ralf Frederik Claas ◽  
Alexander Koch ◽  
Josef M. Pfeilschifter ◽  
Dagmar Meyer zu Heringdorf
Keyword(s):  
Kinase Inhibitor ◽  
Trichostatin A ◽  
Histone Deacetylation ◽  
Wild Type ◽  
Embryonic Fibroblasts ◽  
Hdac Activity ◽  
Histone 3 ◽  
Sphingosine 1 Phosphate ◽  
Wild Type Mefs ◽  
S1p Lyase

Embryonic fibroblasts from S1P (sphingosine-1-phosphate) lyase-deficient mice [Sgpl1−/− MEFs (mouse embryonic fibroblasts)] are characterized by intracellular accumulation of S1P, elevated cytosolic [Ca2+]i and enhanced Ca2+ storage. Since S1P, produced by sphingosine kinase 2 in the nucleus of MCF-7 cells, inhibited HDACs (histone deacetylases) [Hait, Allegood, Maceyka, Strub, Harikumar, Singh, Luo, Marmorstein, Kordula, Milstein et al. (2009) Science 325, 1254–1257], in the present study we analysed whether S1P accumulated in the nuclei of S1P lyase-deficient MEFs and caused HDAC inhibition. Interestingly, nuclear concentrations of S1P were disproportionally elevated in Sgpl1−/− MEFs. HDAC activity was reduced, acetylation of histone 3-Lys9 was increased and the HDAC-regulated gene p21 cyclin-dependent kinase inhibitor was up-regulated in these cells. Furthermore, the expression of HDAC1 and HDAC3 was reduced in Sgpl1−/− MEFs. In wild-type MEFs, acetylation of histone 3-Lys9 was increased by the S1P lyase inhibitor 4-deoxypyridoxine. The non-specific HDAC inhibitor trichostatin A elevated basal [Ca2+]i and enhanced Ca2+ storage, whereas the HDAC1/2/3 inhibitor MGCD0103 elevated basal [Ca2+]i without influence on Ca2+ storage in wild-type MEFs. Overexpression of HDAC1 or HDAC2 reduced the elevated basal [Ca2+]i in Sgpl1−/− MEFs. Taken together, S1P lyase-deficiency was associated with elevated nuclear S1P levels, reduced HDAC activity and down-regulation of HDAC isoenzymes. The decreased HDAC activity in turn contributed to the dysregulation of Ca2+ homoeostasis, particularly to the elevated basal [Ca2+]i, in Sgpl1−/− MEFs.

scholarly journals The Zinc Finger Ikaros Transcription Factor Regulates Pituitary Growth Hormone and Prolactin Gene Expression through Distinct Effects on Chromatin Accessibility

2005 ◽  
Vol 19 (4) ◽  
pp. 1004-1011 ◽  
Author(s):  
Shereen Ezzat ◽  
Shunjiang Yu ◽  
Sylvia L. Asa
Keyword(s):  
Gene Expression ◽  
Chromatin Remodeling ◽  
Trichostatin A ◽  
Zinc Fingers ◽  
Chromatin Accessibility ◽  
Histone Deacetylation ◽  
Protein Levels ◽  
Histone 3 ◽  
Prolactin Gene ◽  
Mrna And Protein Expression

Abstract The Ikaros transcription factors perform critical functions in the control of lymphohematopoiesis and immune regulation. Family members contain multiple zinc fingers that mediate DNA binding but have also been implicated as part of a complex chromatin-remodeling network. We show here that Ikaros is expressed in pituitary mammosomatotrophs where it regulates the GH and prolactin (PRL) genes. Ikaros was detected by Northern and Western blotting in GH4 pituitary mammosomatotroph cells. Wild-type Ikaros (Ik1) inhibits GH mRNA and protein expression but stimulates PRL mRNA and protein levels. Ikaros does not bind directly to the proximal GH promoter but abrogates the effect of the histone deacetylation inhibitor trichostatin A on this region. Ikaros selectively deacetylates histone 3 residues on the proximal transfected or endogenous GH promoter and limits access of the Pit1 activator. In contrast, Ikaros acetylates histone 3 on the proximal PRL promoter and facilitates Pit1 binding to this region in the same cells. These data provide evidence for Ikaros-mediated histone acetylation and chromatin remodeling in the selective regulation of pituitary GH and PRL hormone gene expression.

scholarly journals Dendritic cell sphingosine-1-phosphate lyase regulates thymic egress

2016 ◽  
Vol 213 (12) ◽  
pp. 2773-2791 ◽  
Author(s):  
Jesus Zamora-Pineda ◽  
Ashok Kumar ◽  
Jung H. Suh ◽  
Meng Zhang ◽  
Julie D. Saba
Keyword(s):  
Dendritic Cells ◽  
Dendritic Cell ◽  
Stromal Cells ◽  
Thymic Epithelial Cells ◽  
Homeostatic Regulation ◽  
Wild Type ◽  
Central Tolerance ◽  
Corticomedullary Junction ◽  
Sphingosine 1 Phosphate ◽  
S1p Lyase

T cell egress from the thymus is essential for adaptive immunity and involves chemotaxis along a sphingosine-1-phosphate (S1P) gradient. Pericytes at the corticomedullary junction produce the S1P egress signal, whereas thymic parenchymal S1P levels are kept low through S1P lyase (SPL)–mediated metabolism. Although SPL is robustly expressed in thymic epithelial cells (TECs), in this study, we show that deleting SPL in CD11c+ dendritic cells (DCs), rather than TECs or other stromal cells, disrupts the S1P gradient, preventing egress. Adoptive transfer of peripheral wild-type DCs rescued the egress phenotype of DC-specific SPL knockout mice. These studies identify DCs as metabolic gatekeepers of thymic egress. Combined with their role as mediators of central tolerance, DCs are thus poised to provide homeostatic regulation of thymic export.

scholarly journals Growth Inhibition by the Tumor Suppressor p33ING1 in Immortalized and Primary Cells: Involvement of Two Silencing Domains and Effect of Ras

2005 ◽  
Vol 25 (1) ◽  
pp. 422-431 ◽  
Author(s):  
Frauke Goeman ◽  
Dorit Thormeyer ◽  
Maria Abad ◽  
Manuel Serrano ◽  
Oliver Schmidt ◽  
...  
Keyword(s):  
Cell Cycle ◽  
Tumor Suppressor ◽  
Kinase Inhibitor ◽  
Trichostatin A ◽  
Cell Cycle Control ◽  
Human Fibroblasts ◽  
Cell Types ◽  
Histone Deacetylation ◽  
Dominant Negative ◽  
Mitogen Activated Protein Kinase

ABSTRACT ING1 was identified as an inhibitor of growth and has been described as a tumor suppressor. Furthermore, the expression of ING1 is induced in senescent cells and antisense ING1 extends the proliferative life span of primary human fibroblasts. Cooperation of p33ING1 with p53 has been suggested to be an important function of ING1 in cell cycle control. Intriguingly, it has been shown that p33ING1 is associated with histone acetylation as well as with histone deacetylation function. Here we show that p33ING1 is a potent transcriptional silencer in various cell types. However, the silencing function is independent of the presence of p53. By use of deletion mutants two potent autonomous and transferable silencing domains were identified, but no evidence of an activation domain was found. The amino (N)-terminal silencing domain is sensitive to the histone deacetylase inhibitor trichostatin A (TSA) whereas the carboxy-terminal silencing function is resistant to TSA, suggesting that p33ING1 confers gene silencing through both HDAC-dependent and -independent mechanisms. Interestingly, the presence of oncogenic Ras, which is able to induce premature senescence, increases the p33ING1-mediated silencing function. Moreover, ING1-mediated silencing was reduced by coexpressing dominant-negative Ras or by treatment with the mitogen-activated protein kinase inhibitor PD98059 but not by treatment with SB203580, an inhibitor of the p38 pathway. In addition, we show that both silencing domains of ING1 are involved in cell cycle control, as measured by inhibition of colony formation of immortalized cells and by thymidine incorporation of primary human diploid fibroblasts (HDF). Interestingly, p33ING1 expression induces features of cellular senescence in HDFs.

scholarly journals Phosphorylation of eIF2α is responsible for the failure of the picornavirus internal ribosome entry site to direct translation from Sindbis virus replicons

2013 ◽  
Vol 94 (4) ◽  
pp. 796-806 ◽  
Author(s):  
Miguel Angel Sanz ◽  
Natalia Redondo ◽  
Manuel García-Moreno ◽  
Luis Carrasco
Keyword(s):  
Internal Ribosome Entry Site ◽  
Sindbis Virus ◽  
Encephalomyocarditis Virus ◽  
Initiation Factor ◽  
Wild Type ◽  
Entry Site ◽  
Embryonic Fibroblasts ◽  
Internal Ribosome Entry ◽  
Eif2α Phosphorylation ◽  
Wild Type Mefs

Translation directed by the poliovirus (PV) or encephalomyocarditis virus (EMCV) internal ribosome entry site (IRES) is very inefficient when expressed from Sindbis virus (SV) replicons. This inhibition can be rescued by co-expression of PV 2A protease (2Apro). Inhibition correlates with the extensive phosphorylation of eukaryotic initiation factor (eIF) 2α induced by SV replication. Confirmation that PV or EMCV IRES-driven translation can function when eIF2α is not phosphorylated was obtained in dsRNA-activated protein kinase knockout mouse embryonic fibroblasts (PKR−/− MEFs), where SV replication cannot induce eIF2α phosphorylation, and in variant S51A MEFs that express an unphosphorylatable eIF2α. In these cells, PV or EMCV IRES-dependent translation operated more efficiently than in wild-type MEFs. However, this translation was potently blocked when eIF2α was phosphorylated by the addition of thapsigargin to PKR−/− MEFs. In addition, when wild-type eIF2α was expressed in S51A MEFs or PKR was expressed in PKR−/− MEFs, PV IRES-dependent translation decreased. In both cases, the decrease in PV IRES-dependent translation correlated with the phosphorylation of eIF2α. Notably, PV 2Apro expression rescued PV IRES-driven translation in thapsigargin-treated PKR−/− MEFs. Taken together, these results demonstrated that PV IRES-driven translation can take place from SV replicons if eIF2α remains unphosphorylated. Remarkably, PV IRES-dependent translation was fully functional in this system when PV 2Apro was present, even if eIF2α was phosphorylated.

TDAG51 Deficiency Promotes Migration and Proliferation of Mouse Embryonic Fibroblasts.

Blood ◽  
2006 ◽  
Vol 108 (11) ◽  
pp. 3941-3941
Author(s):  
Gazi S. Hossain ◽  
Jeffrey G. Dickhout ◽  
Christopher A. McCulloch ◽  
Ji Zhou ◽  
Linda May ◽  
...  
Keyword(s):  
Cell Death ◽  
Cell Migration ◽  
Focal Adhesion ◽  
Laser Scanning ◽  
Collagen Gel ◽  
Wild Type ◽  
Mouse Embryonic Fibroblasts ◽  
Inhibitory Antibody ◽  
Embryonic Fibroblasts ◽  
Wild Type Mefs

Abstract T-cell death associated gene 51 (TDAG51) is a member of the pleckstrin homology-related domain family having pro-apoptotic characteristics. Indirect immunofluorescence studies demonstrate that endogenous TDAG51 co-localizes with focal adhesion kinase (FAK), a molecule found within focal adhesion complexes (FACs). FACs are believed to be the structural connection between the extracellular matrix (ECM) and actin cytoskeleton. Given that overexpression of TDAG51 promotes detachment-induced programmed cell death (PCD) and that TDAG51 co-localizes with FAK, it was proposed that deficiency of TDAG51 may stabilize FAC assembly, thereby affecting actin cytoskeletal organization and/or cell migration. To better understand the role of TDAG51 in cell migration, mouse embryonic fibroblasts (MEFs) deficient in TDAG51 were derived from TDAG51-deficient mice and compared to wild type MEFs. TDAG51-deficient MEFs showed increased migration following monolayer disruption or in response to chemotaxis on fibronectin-coated Boyden Chambers. In addition, loss of TDAG51 promotes the proliferation of MEFs. Collagen gel contraction experiments were performed to confirm the aggregate effect of the differences in migration and proliferation observed in TDAG51-deficient MEFs. Interestingly, migration and proliferation can be blocked by active b-integrin inhibitory antibody. In terms of a cellular phenotype, migratory TDAG51-deficient MEFs have distinct filopodial and lamellipodial extentions, compared to migratory wild type MEFs. Laser scanning confocal microscope demonstrated a significant decrease in F-actin stress fibers as well as increased distribution of vinculin within the lamellipodial protrusions of TDAG51-deficient MEFs. Importantly, reintroduction of TDAG51 into TDAG51-deficient MEFs reversed these phenotypic changes. Taken together, our findings suggest that loss of TDAG51 affects cell migration and proliferation through modifying focal adhesion complex assembly and cytoskeletal rearrangements.

scholarly journals The p65 (RelA) Subunit of NF-κB Interacts with the Histone Deacetylase (HDAC) Corepressors HDAC1 and HDAC2 To Negatively Regulate Gene Expression

2001 ◽  
Vol 21 (20) ◽  
pp. 7065-7077 ◽  
Author(s):  
Brian P. Ashburner ◽  
Sandy D. Westerheide ◽  
Albert S. Baldwin
Keyword(s):  
Gene Expression ◽  
Histone Deacetylase ◽  
Chromatin Immunoprecipitation ◽  
Trichostatin A ◽  
Wild Type ◽  
Induced Expression ◽  
Regulate Gene Expression ◽  
Hdac Activity ◽  
Necrosis Factor ◽  
Rel Homology Domain

ABSTRACT Regulation of NF-κB transactivation function is controlled at several levels, including interactions with coactivator proteins. Here we show that the transactivation function of NF-κB is also regulated through interaction of the p65 (RelA) subunit with histone deacetylase (HDAC) corepressor proteins. Our results show that inhibition of HDAC activity with trichostatin A (TSA) results in an increase in both basal and induced expression of an integrated NF-κB-dependent reporter gene. Chromatin immunoprecipitation (ChIP) assays show that TSA treatment causes hyperacetylation of the wild-type integrated NF-κB-dependent reporter but not of a mutant version in which the NF-κB binding sites were mutated. Expression of HDAC1 and HDAC2 repressed tumor necrosis factor (TNF)-induced NF-κB-dependent gene expression. Consistent with this, we show that HDAC1 and HDAC2 target NF-κB through a direct association of HDAC1 with the Rel homology domain of p65. HDAC2 does not interact with NF-κB directly but can regulate NF-κB activity through its association with HDAC1. Finally, we show that inhibition of HDAC activity with TSA causes an increase in both basal and TNF-induced expression of the NF-κB-regulated interleukin-8 (IL-8) gene. Similar to the wild-type integrated NF-κB-dependent reporter, ChIP assays showed that TSA treatment resulted in hyperacetylation of the IL-8 promoter. These data indicate that the transactivation function of NF-κB is regulated in part through its association with HDAC corepressor proteins. Moreover, it suggests that the association of NF-κB with the HDAC1 and HDAC2 corepressor proteins functions to repress expression of NF-κB-regulated genes as well as to control the induced level of expression of these genes.

scholarly journals SMYD3 promotes hepatocellular carcinoma progression by methylating S1PR1 promoters

2021 ◽  
Vol 12 (8) ◽  
Author(s):  
Heyun Zhang ◽  
Zhangyu Zheng ◽  
Rongqin Zhang ◽  
Yongcong Yan ◽  
Yaorong Peng ◽  
...  
Keyword(s):  
Hepatocellular Carcinoma ◽  
Signaling Pathways ◽  
Histone Methylation ◽  
Cell Growth And Migration ◽  
Histone 3 ◽  
Sphingosine 1 Phosphate ◽  
And Migration ◽  
Proliferation And Migration

AbstractHepatocellular carcinoma (HCC) is one of the most common malignancies worldwide. SET and MYND domain-containing protein 3 (SMYD3) has been shown to promote the progression of various types of human cancers, including liver cancer; however, the detailed molecular mechanism is still largely unknown. Here, we report that SMYD3 expression in HCC is an independent prognostic factor for survival and promotes the proliferation and migration of HCC cells. We observed that SMYD3 upregulated sphingosine-1-phosphate receptor 1 (S1PR1) promoter activity by methylating histone 3 (H3K4me3). S1PR1 was expressed at high levels in HCC samples, and high S1PR1 expression was associated with shorter survival. S1PR1 expression was also positively correlated with SMYD3 expression in HCC samples. We confirmed that SMYD3 promotes HCC cell growth and migration in vitro and in vivo by upregulating S1PR1 expression. Further investigations revealed that SMYD3 affects critical signaling pathways associated with the progression of HCC through S1PR1. These findings strongly suggest that SMYD3 has a crucial function in HCC progression that is partially mediated by histone methylation at the downstream gene S1PR1, which affects key signaling pathways associated with carcinogenesis and the progression of HCC.

scholarly journals Akt isoforms differentially regulate neutrophil functions

Blood ◽  
2010 ◽  
Vol 115 (21) ◽  
pp. 4237-4246 ◽  
Author(s):  
Jia Chen ◽  
Haiyang Tang ◽  
Nissim Hay ◽  
Jingsong Xu ◽  
Richard D. Ye
Keyword(s):  
Kinase Inhibitor ◽  
Nicotinamide Adenine Dinucleotide Phosphate ◽  
Leading Edge ◽  
Neutrophil Activation ◽  
Enzyme Release ◽  
Wild Type ◽  
Akt Isoforms ◽  
Phosphoinositide 3 Kinase ◽  
O2 Production

In neutrophils, the phosphoinositide 3-kinase/Akt signaling cascade is involved in migration, degranulation, and O2− production. However, it is unclear whether the Akt kinase isoforms have distinct functions in neutrophil activation. Here we report functional differences between the 2 major Akt isoforms in neutrophil activation on the basis of studies in which we used individual Akt1 and Akt2 knockout mice. Akt2−/− neutrophils exhibited decreased cell migration, granule enzyme release, and O2− production compared with wild-type and Akt1−/− neutrophils. Surprisingly, Akt2 deficiency and pharmacologic inhibition of Akt also abrogated phorbol ester-induced O2− production, which was unaffected by treatment with the phosphoinositide 3-kinase inhibitor LY294002. The decreased O2− production in Akt2−/− neutrophils was accompanied by reduced p47phox phosphorylation and its membrane translocation, suggesting that Akt2 is important for the assembly of phagocyte nicotinamide adenine dinucleotide phosphate oxidase. In wild-type neutrophils, Akt2 but not Akt1 translocated to plasma membrane upon chemoattractant stimulation and to the leading edge in polarized neutrophils. In the absence of Akt2, chemoattractant-induced Akt protein phosphorylation was significantly reduced. These results demonstrate a predominant role of Akt2 in regulating neutrophil functions and provide evidence for differential activation of the 2 Akt isoforms in neutrophils.

scholarly journals AZD1208, a potent and selective pan-Pim kinase inhibitor, demonstrates efficacy in preclinical models of acute myeloid leukemia

Blood ◽  
2014 ◽  
Vol 123 (6) ◽  
pp. 905-913 ◽  
Author(s):  
Erika K. Keeton ◽  
Kristen McEachern ◽  
Keith S. Dillman ◽  
Sangeetha Palakurthi ◽  
Yichen Cao ◽  
...  
Keyword(s):  
Messenger Rna ◽  
Myeloid Leukemia ◽  
Tandem Duplication ◽  
Kinase Inhibitor ◽  
Wild Type ◽  
Internal Tandem Duplication ◽  
Rna Translation ◽  
Key Points ◽  
Messenger Rna Translation ◽  
Flt3 Internal Tandem Duplication

Key Points AZD1208 is a selective pan-Pim kinase inhibitor with efficacy in AML cells, xenografts, and Flt3-internal tandem duplication or Flt3 wild-type patient samples. AML cell growth inhibition is associated with suppression of p70S6K, 4EBP1 phosphorylation, and messenger RNA translation.

scholarly journals Adeno-associated virus Rep proteins antagonize phosphatase PP1 to counteract KAP1 repression of the latent viral genome

2018 ◽  
Vol 115 (15) ◽  
pp. E3529-E3538 ◽  
Author(s):  
Sarah Smith-Moore ◽  
Stuart J. D. Neil ◽  
Cornel Fraefel ◽  
R. Michael Linden ◽  
Mathieu Bollen ◽  
...  
Keyword(s):  
Gene Therapy ◽  
Helper Virus ◽  
Protein Phosphatase 1 ◽  
Wild Type ◽  
Fha Domain ◽  
Adeno Associated Virus ◽  
Histone 3 ◽  
Rep Proteins ◽  
Cellular Factors

Adeno-associated virus (AAV) is a small human Dependovirus whose low immunogenicity and capacity for long-term persistence have led to its widespread use as vector for gene therapy. Despite great recent successes in AAV-based gene therapy, further improvements in vector technology may be hindered by an inadequate understanding of various aspects of basic AAV biology. AAV is unique in that its replication is largely dependent on a helper virus and cellular factors. In the absence of helper virus coinfection, wild-type AAV establishes latency through mechanisms that are not yet fully understood. Challenging the currently held model for AAV latency, we show here that the corepressor Krüppel-associated box domain-associated protein 1 (KAP1) binds the latent AAV2 genome at the rep ORF, leading to trimethylation of AAV2-associated histone 3 lysine 9 and that the inactivation of KAP1 repression is necessary for AAV2 reactivation and replication. We identify a viral mechanism for the counteraction of KAP1 in which interference with the KAP1 phosphatase protein phosphatase 1 (PP1) by the AAV2 Rep proteins mediates enhanced phosphorylation of KAP1-S824 and thus relief from KAP1 repression. Furthermore, we show that this phenomenon involves recruitment of the NIPP1 (nuclear inhibitor of PP1)–PP1α holoenzyme to KAP1 in a manner dependent upon the NIPP1 FHA domain, identifying NIPP1 as an interaction partner for KAP1 and shedding light on the mechanism through which PP1 regulates cellular KAP1 activity.

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