A Class 1 Histone Deacetylase with Potential as an Antifungal Target

PubMed Central

Bauer, Ingo; Varadarajan, Divyavaradhi; Pidroni, Angelo; Gross, Silke; Vergeiner, Stefan; Faber, Birgit; Hermann, Martin; Tribus, Martin; Brosch, Gerald

2016-01-01

ABSTRACT Histone deacetylases (HDACs) remove acetyl moieties from lysine residues at histone tails and nuclear regulatory proteins and thus significantly impact chromatin remodeling and transcriptional regulation in eukaryotes. In recent years, HDACs of filamentous fungi were found to be decisive regulators of genes involved in pathogenicity and the production of important fungal metabolites such as antibiotics and toxins. Here we present proof that one of these enzymes, the class 1 type HDAC RpdA, is of vital importance for the opportunistic human pathogen Aspergillus fumigatus. Recombinant expression of inactivated RpdA shows that loss of catalytic activity is responsible for the lethal phenotype of Aspergillus RpdA null mutants. Furthermore, we demonstrate that a fungus-specific C-terminal region of only a few acidic amino acids is required for both the nuclear localization and catalytic activity of the enzyme in the model organism Aspergillus nidulans. Since strains with single or multiple deletions of other classical HDACs revealed no or only moderate growth deficiencies, it is highly probable that the significant delay of germination and the growth defects observed in strains growing under the HDAC inhibitor trichostatin A are caused primarily by inhibition of catalytic RpdA activity. Indeed, even at low nanomolar concentrations of the inhibitor, the catalytic activity of purified RpdA is considerably diminished. Considering these results, RpdA with its fungus-specific motif represents a promising target for novel HDAC inhibitors that, in addition to their increasing impact as anticancer drugs, might gain in importance as antifungals against life-threatening invasive infections, apart from or in combination with classical antifungal therapy regimes. PMID:27803184

Histone deacetylase inhibition modulates indoleamine 2,3-dioxygenase–dependent DC functions and regulates experimental graft-versus-host disease in mice

PubMed Central

Reddy, Pavan; Sun, Yaping; Toubai, Tomomi; Duran-Struuck, Raimon; Clouthier, Shawn G.; Weisiger, Elizabeth; Maeda, Yoshinobu; Tawara, Isao; Krijanovski, Oleg; Gatza, Erin; Liu, Chen; Malter, Chelsea; Mascagni, Paolo; Dinarello, Charles A.; Ferrara, James L.M.

2008-01-01

Histone deacetylase (HDAC) inhibitors are antitumor agents that also have antiinflammatory properties. However, the mechanisms of their immunomodulatory functions are not known. We investigated the mechanisms of action of 2 HDAC inhibitors, suberoylanilide hydroxamic acid (SAHA) and ITF 2357, on mouse DC responses. Pretreatment of DCs with HDAC inhibitors significantly reduced TLR-induced secretion of proinflammatory cytokines, suppressed the expression of CD40 and CD80, and reduced the in vitro and in vivo allostimulatory responses induced by the DCs. In addition, injection of DCs treated ex vivo with HDAC inhibitors reduced experimental graft-versus-host disease (GVHD) in a murine allogeneic BM transplantation model. Exposure of DCs to HDAC inhibitors increased expression of indoleamine 2,3-dioxygenase (IDO), a suppressor of DC function. Blockade of IDO in WT DCs with siRNA and with DCs from IDO-deficient animals caused substantial reversal of HDAC inhibition–induced in vitro suppression of DC-stimulated responses. Direct injection of HDAC inhibitors early after allogeneic BM transplantation to chimeric animals whose BM-derived cells lacked IDO failed to protect from GVHD, demonstrating an in vivo functional role for IDO. Together, these data show that HDAC inhibitors regulate multiple DC functions through the induction of IDO and suggest that they may represent a novel class of agents to treat immune-mediated diseases. PMID:18568076

Discovery of aliphatic-chain hydroxamates containing indole derivatives with potent class I histone deacetylase inhibitory activities.

PubMed

Chao, Shi-Wei; Chen, Liang-Chieh; Yu, Chia-Chun; Liu, Chang-Yi; Lin, Tony Eight; Guh, Jih-Hwa; Wang, Chen-Yu; Chen, Chun-Yung; Hsu, Kai-Cheng; Huang, Wei-Jan

2018-01-01

Histone deacetylase (HDAC) is a validated drug target for various diseases. This study combined indole recognition cap with SAHA, an FDA-approved HDAC inhibitor used to treat cutaneous T-cell lymphoma (CTCL). The structure activity relationship of the resulting compounds that inhibited HDAC was disclosed as well. Some compounds exhibited much stronger inhibitory activities than SAHA. We identified two meta-series compounds 6j and 6k with a two-carbon linker had IC 50 values of 3.9 and 4.5 nM for HDAC1, respectively. In contrast, the same oriented compounds with longer carbon chain linkers showed weaker inhibition. The result suggests that the linker chain length greatly contributed to enzyme inhibitory potency. In addition, comparison of enzyme-inhibiting activity between the compounds and SAHA showed that compounds 6j and 6k displayed higher inhibiting activity for class I (HDAC1, -2, -3 and -8). The molecular docking and structure analysis revealed structural differences with the inhibitor cap and metal-binding regions between the HDAC isozymes that affect interactions with the inhibitors and play a key role for selectivity. Further biological evaluation showed multiple cellular effects associated with compounds 6j- and 6k-induced HDAC inhibitory activity. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

Enhanced Histone Deacetylase Activity in Malignant Melanoma Provokes RAD51 and FANCD2-Triggered Drug Resistance.

PubMed

Krumm, Andrea; Barckhausen, Christina; Kücük, Pelin; Tomaszowski, Karl-Heinz; Loquai, Carmen; Fahrer, Jörg; Krämer, Oliver Holger; Kaina, Bernd; Roos, Wynand Paul

2016-05-15

DNA-damaging anticancer drugs remain a part of metastatic melanoma therapy. Epigenetic reprogramming caused by increased histone deacetylase (HDAC) activity arising during tumor formation may contribute to resistance of melanomas to the alkylating drugs temozolomide, dacarbazine, and fotemustine. Here, we report on the impact of class I HDACs on the response of malignant melanoma cells treated with alkylating agents. The data show that malignant melanomas in situ contain a high level of HDAC1/2 and malignant melanoma cells overexpress HDAC1/2/3 compared with noncancer cells. Furthermore, pharmacologic inhibition of class I HDACs sensitizes malignant melanoma cells to apoptosis following exposure to alkylating agents, while not affecting primary melanocytes. Inhibition of HDAC1/2/3 caused sensitization of melanoma cells to temozolomide in vitro and in melanoma xenografts in vivo HDAC1/2/3 inhibition resulted in suppression of DNA double-strand break (DSB) repair by homologous recombination because of downregulation of RAD51 and FANCD2. This sensitized cells to the cytotoxic DNA lesion O(6)-methylguanine and caused a synthetic lethal interaction with the PARP-1 inhibitor olaparib. Furthermore, knockdown experiments identified HDAC2 as being responsible for the regulation of RAD51. The influence of class I HDACs on DSB repair by homologous recombination and the possible clinical implication on malignant melanoma therapy with temozolomide and other alkylating drugs suggests a combination approach where class I HDAC inhibitors such as valproic acid or MS-275 (entinostat) appear to counteract HDAC- and RAD51/FANCD2-mediated melanoma cell resistance. Cancer Res; 76(10); 3067-77. ©2016 AACR. ©2016 American Association for Cancer Research.

Overlapping and Divergent Actions of Structurally Distinct Histone Deacetylase Inhibitors in Cardiac Fibroblasts

PubMed Central

Schuetze, Katherine B.; Stratton, Matthew S.; Blakeslee, Weston W.; Wempe, Michael F.; Wagner, Florence F.; Holson, Edward B.; Kuo, Yin-Ming; Andrews, Andrew J.; Gilbert, Tonya M.; Hooker, Jacob M.

2017-01-01

Inhibitors of zinc-dependent histone deacetylases (HDACs) profoundly affect cellular function by altering gene expression via changes in nucleosomal histone tail acetylation. Historically, investigators have employed pan-HDAC inhibitors, such as the hydroxamate trichostatin A (TSA), which simultaneously targets members of each of the three zinc-dependent HDAC classes (classes I, II, and IV). More recently, class- and isoform-selective HDAC inhibitors have been developed, providing invaluable chemical biology probes for dissecting the roles of distinct HDACs in the control of various physiologic and pathophysiological processes. For example, the benzamide class I HDAC-selective inhibitor, MGCD0103 [N-(2-aminophenyl)-4-[[(4-pyridin-3-ylpyrimidin-2-yl)amino]methyl] benzamide], was shown to block cardiac fibrosis, a process involving excess extracellular matrix deposition, which often results in heart dysfunction. Here, we compare the mechanisms of action of structurally distinct HDAC inhibitors in isolated primary cardiac fibroblasts, which are the major extracellular matrix–producing cells of the heart. TSA, MGCD0103, and the cyclic peptide class I HDAC inhibitor, apicidin, exhibited a common ability to enhance histone acetylation, and all potently blocked cardiac fibroblast cell cycle progression. In contrast, MGCD0103, but not TSA or apicidin, paradoxically increased expression of a subset of fibrosis-associated genes. Using the cellular thermal shift assay, we provide evidence that the divergent effects of HDAC inhibitors on cardiac fibroblast gene expression relate to differential engagement of HDAC1- and HDAC2-containing complexes. These findings illustrate the importance of employing multiple compounds when pharmacologically assessing HDAC function in a cellular context and during HDAC inhibitor drug development. PMID:28174211

Histone deacetylase expression patterns in developing murine optic nerve

PubMed Central

2014-01-01

Background Histone deacetylases (HDACs) play important roles in glial cell development and in disease states within multiple regions of the central nervous system. However, little is known about HDAC expression or function within the optic nerve. As a first step in understanding the role of HDACs in optic nerve, this study examines the spatio-temporal expression patterns of methylated histone 3 (K9), acetylated histone 3 (K18), and HDACs 1–6 and 8–11 in the developing murine optic nerve head. Results Using RT-qPCR, western blot and immunofluorescence, three stages were analyzed: embryonic day 16 (E16), when astrocyte precursors are found in the optic stalk, postnatal day 5 (P5), when immature astrocytes and oligodendrocytes are found throughout the optic nerve, and P30, when optic nerve astrocytes and oligodendrocytes are mature. Acetylated and methylated histone H3 immunoreactivity was co-localized in the nuclei of most SOX2 positive glia within the optic nerve head and adjacent optic nerve at all developmental stages. HDACs 1–11 were expressed in the optic nerve glial cells at all three stages of optic nerve development in the mouse, but showed temporal differences in overall levels and subcellular localization. HDACs 1 and 2 were predominantly nuclear throughout optic nerve development and glial cell maturation. HDACs 3, 5, 6, 8, and 11 were predominantly cytoplasmic, but showed nuclear localization in at least one stage of optic nerve development. HDACs 4, 9 and10 were predominantly cytoplasmic, with little to no nuclear expression at any time during the developmental stages examined. Conclusions Our results showing that HDACs 1, 2, 3, 5, 6, 8, and 11 were each localized to the nuclei of SOX2 positive glia at some stages of optic nerve development and maturation and extend previous reports of HDAC expression in the aging optic nerve. These HDACs are candidates for further research to understand how chromatin remodeling through acetylation, deacetylation and methylation contributes to glial development as well as their injury response. PMID:25011550

The anti-tumor effect of HDAC inhibition in a human pancreas cancer model is significantly improved by the simultaneous inhibition of cyclooxygenase 2.

PubMed

Peulen, Olivier; Gonzalez, Arnaud; Peixoto, Paul; Turtoi, Andrei; Mottet, Denis; Delvenne, Philippe; Castronovo, Vincent

2013-01-01

Pancreatic ductal adenocarcinoma is the fourth leading cause of cancer death worldwide, with no satisfactory treatment to date. In this study, we tested whether the combined inhibition of cyclooxygenase-2 (COX-2) and class I histone deacetylase (HDAC) may results in a better control of pancreatic ductal adenocarcinoma. The impact of the concomitant HDAC and COX-2 inhibition on cell growth, apoptosis and cell cycle was assessed first in vitro on human pancreas BxPC-3, PANC-1 or CFPAC-1 cells treated with chemical inhibitors (SAHA, MS-275 and celecoxib) or HDAC1/2/3/7 siRNA. To test the potential antitumoral activity of this combination in vivo, we have developed and characterized, a refined chick chorioallantoic membrane tumor model that histologically and proteomically mimics human pancreatic ductal adenocarcinoma. The combination of HDAC1/3 and COX-2 inhibition significantly impaired proliferation of BxPC-3 cells in vitro and stalled entirely the BxPC-3 cells tumor growth onto the chorioallantoic membrane in vivo. The combination was more effective than either drug used alone. Consistently, we showed that both HDAC1 and HDAC3 inhibition induced the expression of COX-2 via the NF-kB pathway. Our data demonstrate, for the first time in a Pancreatic Ductal Adenocarcinoma (PDAC) model, a significant action of HDAC and COX-2 inhibitors on cancer cell growth, which sets the basis for the development of potentially effective new combinatory therapies for pancreatic ductal adenocarcinoma patients.

Selective targeting of the repressive transcription factors YY1 and cMyc to disrupt quiescent human immunodeficiency viruses.

PubMed

Barton, Kirston; Margolis, David

2013-02-01

Quiescent HIV-1 infection of resting CD4(+) T cells is an obstacle to eradication of HIV-1 infection. These reservoirs are maintained, in part, by repressive complexes that bind to the HIV-1 long terminal repeat (LTR) and recruit histone deacetylases (HDACs). cMyc and YY1 are two transcription factors that are recruited as part of well-described, distinct complexes to the HIV-1 LTR and in turn recruit HDACs. In prior studies, depletion of single factors that recruit HDAC1 in various cell lines was sufficient to upregulate LTR activity. We used short hairpin RNAs (shRNAs) to test the effect of targeted disruption of a single transcription factor on quiescent proviruses in T cell lines. In this study, we found that depletion of YY1 significantly increases mRNA and protein expression from the HIV-1 promoter in some contexts, but does not affect HDAC1, HDAC2, HDAC3, or acetylated histone 3 occupancy of the HIV-1 LTR. Conversely, depletion of cMyc or cMyc and YY1 does not significantly alter the level of transcription from the LTR or affect recruitment of HDACs to the HIV-1 LTR. Furthermore, global inhibition of HDACs with the HDAC inhibitor suberoylanilide hydroxamic acid (SAHA) enhanced the increase in LTR transcription in cells that were depleted of YY1.These findings show that despite prior isolated findings, redundancy in repressors of HIV-1 LTR expression will require selective targeting of multiple restrictive mechanisms to comprehensively induce the escape of quiescent proviruses from latency.

Overlapping and Divergent Actions of Structurally Distinct Histone Deacetylase Inhibitors in Cardiac Fibroblasts.

PubMed

Schuetze, Katherine B; Stratton, Matthew S; Blakeslee, Weston W; Wempe, Michael F; Wagner, Florence F; Holson, Edward B; Kuo, Yin-Ming; Andrews, Andrew J; Gilbert, Tonya M; Hooker, Jacob M; McKinsey, Timothy A

2017-04-01

Inhibitors of zinc-dependent histone deacetylases (HDACs) profoundly affect cellular function by altering gene expression via changes in nucleosomal histone tail acetylation. Historically, investigators have employed pan-HDAC inhibitors, such as the hydroxamate trichostatin A (TSA), which simultaneously targets members of each of the three zinc-dependent HDAC classes (classes I, II, and IV). More recently, class- and isoform-selective HDAC inhibitors have been developed, providing invaluable chemical biology probes for dissecting the roles of distinct HDACs in the control of various physiologic and pathophysiological processes. For example, the benzamide class I HDAC-selective inhibitor, MGCD0103 [ N -(2-aminophenyl)-4-[[(4-pyridin-3-ylpyrimidin-2-yl)amino]methyl] benzamide], was shown to block cardiac fibrosis, a process involving excess extracellular matrix deposition, which often results in heart dysfunction. Here, we compare the mechanisms of action of structurally distinct HDAC inhibitors in isolated primary cardiac fibroblasts, which are the major extracellular matrix-producing cells of the heart. TSA, MGCD0103, and the cyclic peptide class I HDAC inhibitor, apicidin, exhibited a common ability to enhance histone acetylation, and all potently blocked cardiac fibroblast cell cycle progression. In contrast, MGCD0103, but not TSA or apicidin, paradoxically increased expression of a subset of fibrosis-associated genes. Using the cellular thermal shift assay, we provide evidence that the divergent effects of HDAC inhibitors on cardiac fibroblast gene expression relate to differential engagement of HDAC1- and HDAC2-containing complexes. These findings illustrate the importance of employing multiple compounds when pharmacologically assessing HDAC function in a cellular context and during HDAC inhibitor drug development. Copyright © 2017 by The American Society for Pharmacology and Experimental Therapeutics.

Sulforaphane Reverses the Expression of Various Tumor Suppressor Genes by Targeting DNMT3B and HDAC1 in Human Cervical Cancer Cells

PubMed Central

Ali Khan, Munawwar; Kedhari Sundaram, Madhumitha; Hamza, Amina; Quraishi, Uzma; Gunasekera, Dian; Ramesh, Laveena; Al Alami, Usama; Ansari, Mohammad Zeeshan; Rizvi, Tahir A.; Sharma, Chhavi

2015-01-01

Sulforaphane (SFN) may hinder carcinogenesis by altering epigenetic events in the cells; however, its molecular mechanisms are unclear. The present study investigates the role of SFN in modifying epigenetic events in human cervical cancer cells, HeLa. HeLa cells were treated with SFN (2.5 µM) for a period of 0, 24, 48, and 72 hours for all experiments. After treatment, expressions of DNMT3B, HDAC1, RARβ, CDH1, DAPK1, and GSTP1 were studied using RT-PCR while promoter DNA methylation of tumor suppressor genes (TSGs) was studied using MS-PCR. Inhibition assays of DNA methyl transferases (DNMTs) and histone deacetylases (HDACs) were performed at varying time points. Molecular modeling and docking studies were performed to explore the possible interaction of SFN with HDAC1 and DNMT3B. Time-dependent exposure to SFN decreases the expression of DNMT3B and HDAC1 and significantly reduces the enzymatic activity of DNMTs and HDACs. Molecular modeling data suggests that SFN may interact directly with DNMT3B and HDAC1 which may explain the inhibitory action of SFN. Interestingly, time-dependent reactivation of the studied TSGs via reversal of methylation in SFN treated cells correlates well with its impact on the epigenetic alterations accumulated during cancer development. Thus, SFN may have significant implications for epigenetic based therapy. PMID:26161119

Metastatic prostate cancer-associated P62 inhibits autophagy flux and promotes epithelial to mesenchymal transition by sustaining the level of HDAC6.

PubMed

Jiang, Xianhan; Huang, Yiqiao; Liang, Xue; Jiang, Funeng; He, Yongzhong; Li, Tian; Xu, Guibin; Zhao, Haibo; Yang, Weiqing; Jiang, Ganggang; Su, Zhengming; Jiang, Lingke; Liu, Leyuan

2018-05-01

P62 (also named sequestosome-1, SQSTM1) is involved in autophagy regulation through multiple pathways. It interacts with autophagosomes-associated LC3-II and ubiquitinated protein aggregates to engulf the aggregates in autophagosomes, interacts with HDAC6 to inhibit its deacetylase activity to maintain the levels of acetylated α-tubulin and stabilities of microtubules to enhance autophagosome trafficking, and regulates autophagy initiation and cell survival. We performed immunohistochemistry staining of P62 in prostate tissues from prostate cancer patients and found that levels of P62 in patients with prostate adenocarcinomas (PCA) are significantly higher than those in patients with benign prostate hyperplasia (BPH). High levels of P62 predict high tumor grade and high intensity of metastasis. We created prostate cancer cell lines stably overexpressing P62 and then suppress the expression of P62 in the cell line stably overexpressing P62 with CRISPR technology. Cell proliferation assay with crystal violet, cell migration assay, cell invasion assay, Western blot analysis, and confocal fluorescent microscopy were conducted to test the impact of altered levels of P62 on the growth, migration, invasion, epithelial-to-mesenchymal transition, autophagy flux, HDAC6 activity, and microtubular acetylation of cancer cells. P62 increased the levels of HDAC6 and reduced the acetylation of α-tubulin and the stability of microtubules. Consequently, high levels of P62 caused a promotion of epithelial-to-mesenchymal transition in addition to an impairment of autophagy flux, and further led to an enhancement of proliferation, migration, and invasion of prostate cancer cells. P62 promotes metastasis of PCA by sustaining the level of HDAC6 to inhibit autophagy and promote epithelial-to-mesenchymal transition. © 2018 Wiley Periodicals, Inc.

Multiple histone deacetylases are recruited by corepressor Sin3 and contribute to gene repression mediated by Opi1 regulator of phospholipid biosynthesis in the yeast Saccharomyces cerevisiae.

PubMed

Grigat, Mathias; Jäschke, Yvonne; Kliewe, Felix; Pfeifer, Matthias; Walz, Susanne; Schüller, Hans-Joachim

2012-06-01

Yeast genes of phospholipid biosynthesis are negatively regulated by repressor protein Opi1 when precursor molecules inositol and choline (IC) are available. Opi1-triggered gene repression is mediated by recruitment of the Sin3 corepressor complex. In this study, we systematically investigated the regulatory contribution of subunits of Sin3 complexes and identified Pho23 as important for IC-dependent gene repression. Two non-overlapping regions within Pho23 mediate its direct interaction with Sin3. Previous work has shown that Sin3 recruits the histone deacetylase (HDAC) Rpd3 to execute gene repression. While deletion of SIN3 strongly alleviates gene repression by IC, an rpd3 null mutant shows almost normal regulation. We thus hypothesized that various HDACs may contribute to Sin3-mediated repression of IC-regulated genes. Indeed, a triple mutant lacking HDACs, Rpd3, Hda1 and Hos1, could phenocopy a sin3 single mutant. We show that these proteins are able to contact Sin3 in vitro and in vivo and mapped three distinct HDAC interaction domains, designated HID1, HID2 and HID3. HID3, which is identical to the previously described structural motif PAH4 (paired amphipathic helix), can bind all HDACs tested. Chromatin immunoprecipitation studies finally confirmed that Hda1 and Hos1 are recruited to promoters of phospholipid biosynthetic genes INO1 and CHO2.

Identification of novel isoform-selective inhibitors within class I histone deacetylases.

PubMed

Hu, Erding; Dul, Edward; Sung, Chiu-Mei; Chen, Zunxuan; Kirkpatrick, Robert; Zhang, Gui-Feng; Johanson, Kyung; Liu, Ronggang; Lago, Amparo; Hofmann, Glenn; Macarron, Ricardo; de los Frailes, Maite; Perez, Paloma; Krawiec, John; Winkler, James; Jaye, Michael

2003-11-01

Histone deacetylases (HDACs) represent an expanding family of protein modifying-enzymes that play important roles in cell proliferation, chromosome remodeling, and gene transcription. We have previously shown that recombinant human HDAC8 can be expressed in bacteria and retain its catalytic activity. To further explore the catalytic activity of HDACs, we expressed two additional human class I HDACs, HDAC1 and HDAC3, in baculovirus. Recombinant HDAC1 and HDAC3 fusion proteins remained soluble and catalytically active and were purified to near homogeneity. Interestingly, trichostatin (TSA) was found to be a potent inhibitor for all three HDACs (IC50 value of approximately 0.1-0.3 microM), whereas another HDAC inhibitor MS-27-275 (N-(2-aminophenyl)-4-[N-(pyridin-3-methyloxycarbonyl)-aminomethyl]benzamide) preferentially inhibited HDAC1 (IC50 value of approximately 0.3 microM) versus HDAC3 (IC50 value of approximately 8 microM) and had no inhibitory activity toward HDAC8 (IC50 value >100 microM). MS-27-275 as well as TSA increased histone H4 acetylation, induced apoptosis in the human colon cancer cell line SW620, and activated the simian virus 40 early promoter. HDAC1 protein was more abundantly expressed in SW620 cells compared with that of HDAC3 and HDAC8. Using purified recombinant HDAC proteins, we identified several novel HDAC inhibitors that preferentially inhibit HDAC1 or HDAC8. These inhibitors displayed distinct properties in inducing histone acetylation and reporter gene expression. These results suggest selective HDAC inhibitors could be identified using recombinantly expressed HDACs and that HDAC1 may be a promising therapeutic target for designing HDAC inhibitors for proliferative diseases such as cancer.

HDACs and HDAC inhibitors in urothelial carcinoma - perspectives for an antineoplastic treatment.

PubMed

Pinkerneil, Maria; Hoffmann, Michèle J; Schulz, Wolfgang A; Niegisch, Günter

2017-01-11

Histone deacetylases (HDACs) influence diverse cellular processes and may contribute to tumor development and progression by multiple mechanisms. Class I HDACs are often overexpressed in cancers contributing to a genome-wide epigenetic state permitting increased proliferation, and diminished apoptosis and cell differentiation. Class IIA and IIB isoenzymes may likewise contribute to tumorigenesis as components of specific intranuclear repressor complexes or regulators of posttranslational protein modifications. As HDAC inhibitors may counteract these tumorigenic effects several of these compounds are currently tested in clinical trials. HDAC inhibitors are also considered for urothelial carcinoma, where novel therapeutic drugs are urgently required. However, only modest antineoplastic activity has been observed with isoenzyme-unspecific pan-HDAC inhibitors. Therefore, inhibition of specific HDAC isoenzymes might be more efficacious and tumor-specific. Here, we systematically review knowledge on the expression, function and suitability as therapeutic targets of the 11 classical HDACs in UC. Overall, the class I HDACs HDAC1 and HDAC2 are the most promising targets for antineoplastic treatment. In contrast, targeting HDAC8 and HDAC6 is likely to be of minor relevance in urothelial carcinoma. Class IIA HDACs like HDAC4 require further study, since their downregulation rather than upregulation could be involved in urothelial carcinoma pathogenesis.

Towards isozyme-selective HDAC inhibitors for interrogating disease.

PubMed

Gupta, Praveer; Reid, Robert C; Iyer, Abishek; Sweet, Matthew J; Fairlie, David P

2012-01-01

Histone deacetylase (HDAC) enzymes have emerged as promising targets for the treatment of a wide range of human diseases, including cancers, inflammatory and metabolic disorders, immunological, cardiovascular, and infectious diseases. At present, such applications are limited by the lack of selective inhibitors available for each of the eighteen HDAC enzymes, with most currently available HDAC inhibitors having broad-spectrum activity against multiple HDAC enzymes. Such broad-spectrum activity maybe useful in treating some diseases like cancers, but can be detrimental due to cytotoxic side effects that accompany prolonged treatment of chronic diseased states. Here we summarize progress towards the design and discovery of HDAC inhibitors that are selective for some of the eleven zinc-containing classical HDAC enzymes, and identify opportunities to use such isozyme-selective inhibitors as chemical probes for interrogating the biological roles of individual HDAC enzymes in diseases.

Histone deacetylase 3 regulates the inflammatory gene expression programme of rheumatoid arthritis fibroblast-like synoviocytes

PubMed Central

Angiolilli, Chiara; Kabala, Pawel A; Van Baarsen, Iris M; Ferguson, Bradley S; García, Samuel; Malvar Fernandez, Beatriz; McKinsey, Timothy A; Tak, Paul P; Fossati, Gianluca; Mascagni, Paolo; Baeten, Dominique L; Reedquist, Kris A

2017-01-01

Objectives Non-selective histone deacetylase (HDAC) inhibitors (HDACi) have demonstrated anti-inflammatory properties in both in vitro and in vivo models of rheumatoid arthritis (RA). Here, we investigated the potential contribution of specific class I and class IIb HDACs to inflammatory gene expression in RA fibroblast-like synoviocytes (FLS). Methods RA FLS were incubated with pan-HDACi (ITF2357, givinostat) or selective HDAC1/2i, HDAC3/6i, HDAC6i and HDAC8i. Alternatively, FLS were transfected with HDAC3, HDAC6 or interferon (IFN)-α/β receptor alpha chain (IFNAR1) siRNA. mRNA expression of interleukin (IL)-1β-inducible genes was measured by quantitative PCR (qPCR) array and signalling pathway activation by immunoblotting and DNA-binding assays. Results HDAC3/6i, but not HDAC1/2i and HDAC8i, significantly suppressed the majority of IL-1β-inducible genes targeted by pan-HDACi in RA FLS. Silencing of HDAC3 expression reproduced the effects of HDAC3/6i on gene regulation, contrary to HDAC6-specific inhibition and HDAC6 silencing. Screening of the candidate signal transducers and activators of transcription (STAT)1 transcription factor revealed that HDAC3/6i abrogated STAT1 Tyr701 phosphorylation and DNA binding, but did not affect STAT1 acetylation. HDAC3 activity was required for type I IFN production and subsequent STAT1 activation in FLS. Suppression of type I IFN release by HDAC3/6i resulted in reduced expression of a subset of IFN-dependent genes, including the chemokines CXCL9 and CXCL11. Conclusions Inhibition of HDAC3 in RA FLS largely recapitulates the effects of pan-HDACi in suppressing inflammatory gene expression, including type I IFN production in RA FLS. Our results identify HDAC3 as a potential therapeutic target in the treatment of RA and type I IFN-driven autoimmune diseases. PMID:27457515

β-Adrenergic Stimulation Induces Histone Deacetylase 5 (HDAC5) Nuclear Accumulation in Cardiomyocytes by B55α-PP2A-Mediated Dephosphorylation.

PubMed

Weeks, Kate L; Ranieri, Antonella; Karaś, Agnieszka; Bernardo, Bianca C; Ashcroft, Alexandra S; Molenaar, Chris; McMullen, Julie R; Avkiran, Metin

2017-03-25

Class IIa histone deacetylase (HDAC) isoforms such as HDAC5 are critical signal-responsive repressors of maladaptive cardiomyocyte hypertrophy, through nuclear interactions with transcription factors including myocyte enhancer factor-2. β-Adrenoceptor (β-AR) stimulation, a signal of fundamental importance in regulating cardiac function, has been proposed to induce both phosphorylation-independent nuclear export and phosphorylation-dependent nuclear accumulation of cardiomyocyte HDAC5. The relative importance of phosphorylation at Ser259/Ser498 versus Ser279 in HDAC5 regulation is also controversial. We aimed to determine the impact of β-AR stimulation on the phosphorylation, localization, and function of cardiomyocyte HDAC5 and delineate underlying molecular mechanisms. A novel 3-dimensional confocal microscopy method that objectively quantifies the whole-cell nuclear/cytoplasmic distribution of green fluorescent protein tagged HDAC5 revealed the β-AR agonist isoproterenol to induce β 1 -AR-mediated and protein kinase A-dependent HDAC5 nuclear accumulation in adult rat cardiomyocytes, which was accompanied by dephosphorylation at Ser259/279/498. Mutation of Ser259/Ser498 to Ala promoted HDAC5 nuclear accumulation and myocyte enhancer factor-2 inhibition, whereas Ser279 ablation had no such effect and did not block isoproterenol-induced nuclear accumulation. Inhibition of the Ser/Thr phosphatase PP2A blocked isoproterenol-induced HDAC5 dephosphorylation. Co-immunoprecipitation revealed a specific interaction of HDAC5 with the PP2A targeting subunit B55α, as well as catalytic and scaffolding subunits, which increased >3-fold with isoproterenol. Knockdown of B55α in neonatal cardiomyocytes attenuated isoproterenol-induced HDAC5 dephosphorylation. β-AR stimulation induces HDAC5 nuclear accumulation in cardiomyocytes by a mechanism that is protein kinase A-dependent but requires B55α-PP2A-mediated dephosphorylation of Ser259/Ser498 rather than protein kinase A-mediated phosphorylation of Ser279. © 2017 The Authors. Published on behalf of the American Heart Association, Inc., by Wiley Blackwell.

Stereoselective HDAC inhibition from cysteine-derived zinc-binding groups.

PubMed

Butler, Kyle V; He, Rong; McLaughlin, Kathryn; Vistoli, Giulio; Langley, Brett; Kozikowski, Alan P

2009-08-01

A series of small-molecule histone deacetylase (HDAC) inhibitors, which feature zinc binding groups derived from cysteine, were synthesized. These inhibitors were tested against multiple HDAC isoforms, and the most potent, compound 10, was determined to have IC(50) values below 1 microM. The compounds were also tested in a cellular assay of oxidative stress-induced neurodegeneration. Many of the inhibitors gave near-complete protection against cell death at 10 microM without the neurotoxicity seen with hydroxamic acid-based inhibitors, and were far more neuroprotective than HDAC inhibitors currently in clinical trials. Both enantiomers of cysteine were used in the synthesis of a variety of novel zinc-binding groups (ZBGs). Derivatives of L-cysteine were active in the HDAC inhibition assays, while the derivatives of D-cysteine were inactive. Notably, the finding that both the D- and L-cysteine derivatives were active in the neuroprotection assays suggests that multiple mechanisms are working to protect the neurons from cell death. Molecular modeling was employed to investigate the differences in inhibitory activity between the HDAC inhibitors generated from the two enantiomeric forms of cysteine.

Histone deacetylase 6 inhibition reduces cysts by decreasing cAMP and Ca2+ in knock-out mouse models of polycystic kidney disease.

PubMed

Yanda, Murali K; Liu, Qiangni; Cebotaru, Valeriu; Guggino, William B; Cebotaru, Liudmila

2017-10-27

Autosomal dominant polycystic kidney disease (ADPKD) is associated with progressive enlargement of multiple renal cysts, often leading to renal failure that cannot be prevented by a current treatment. Two proteins encoded by two genes are associated with ADPKD: PC1 ( pkd1 ), primarily a signaling molecule, and PC2 ( pkd2 ), a Ca 2+ channel. Dysregulation of cAMP signaling is central to ADPKD, but the molecular mechanism is unresolved. Here, we studied the role of histone deacetylase 6 (HDAC6) in regulating cyst growth to test the possibility that inhibiting HDAC6 might help manage ADPKD. Chemical inhibition of HDAC6 reduced cyst growth in PC1-knock-out mice. In proximal tubule-derived, PC1-knock-out cells, adenylyl cyclase 6 and 3 (AC6 and -3) are both expressed. AC6 protein expression was higher in cells lacking PC1, compared with control cells containing PC1. Intracellular Ca 2+ was higher in PC1-knock-out cells than in control cells. HDAC inhibition caused a drop in intracellular Ca 2+ and increased ATP-simulated Ca 2+ release. HDAC6 inhibition reduced the release of Ca 2+ from the endoplasmic reticulum induced by thapsigargin, an inhibitor of endoplasmic reticulum Ca 2+ -ATPase. HDAC6 inhibition and treatment of cells with the intracellular Ca 2+ chelator 1,2-bis(2-aminophenoxy)ethane- N , N , N ', N '-tetraacetic acid tetrakis(acetoxymethyl ester) reduced cAMP levels in PC1-knock-out cells. Finally, the calmodulin inhibitors W-7 and W-13 reduced cAMP levels, and W-7 reduced cyst growth, suggesting that AC3 is involved in cyst growth regulated by HDAC6. We conclude that HDAC6 inhibition reduces cell growth primarily by reducing intracellular cAMP and Ca 2+ levels. Our results provide potential therapeutic targets that may be useful as treatments for ADPKD. © 2017 by The American Society for Biochemistry and Molecular Biology, Inc.

Involvement of HDAC1 and HDAC3 in the Pathology of Polyglutamine Disorders: Therapeutic Implications for Selective HDAC1/HDAC3 Inhibitors

PubMed Central

Thomas, Elizabeth A.

2014-01-01

Histone deacetylases (HDACs) enzymes, which affect the acetylation status of histones and other important cellular proteins, have been recognized as potentially useful therapeutic targets for a broad range of human disorders. Emerging studies have demonstrated that different types of HDAC inhibitors show beneficial effects in various experimental models of neurological disorders. HDAC enzymes comprise a large family of proteins, with18 HDAC enzymes currently identified in humans. Hence, an important question for HDAC inhibitor therapeutics is which HDAC enzyme(s) is/are important for the amelioration of disease phenotypes, as it has become clear that individual HDAC enzymes play different biological roles in the brain. This review will discuss evidence supporting the involvement of HDAC1 and HDAC3 in polyglutamine disorders, including Huntington’s disease, and the use of HDAC1- and HDAC3-selective HDAC inhibitors as therapeutic intervention for these disorders. Further, while HDAC inhibitors are known alter chromatin structure resulting in changes in gene transcription, understanding the exact mechanisms responsible for the preclinical efficacy of these compounds remains a challenge. The potential chromatin-related and non-chromatin-related mechanisms of action of selective HDAC inhibitors will also be discussed. PMID:24865773

Histone deacetylase 4 selectively contributes to podocyte injury in diabetic nephropathy.

PubMed

Wang, Xiaojie; Liu, Jiang; Zhen, Junhui; Zhang, Chun; Wan, Qiang; Liu, Guangyi; Wei, Xinbing; Zhang, Yan; Wang, Ziying; Han, Huirong; Xu, Huiyan; Bao, Chanchan; Song, Zhenyu; Zhang, Xiumei; Li, Ningjun; Yi, Fan

2014-10-01

Studies have highlighted the importance of histone deacetylase (HDAC)-mediated epigenetic processes in the development of diabetic complications. Inhibitors of HDAC are a novel class of therapeutic agents in diabetic nephropathy, but currently available inhibitors are mostly nonselective inhibit multiple HDACs, and different HDACs serve very distinct functions. Therefore, it is essential to determine the role of individual HDACs in diabetic nephropathy and develop HDAC inhibitors with improved specificity. First, we identified the expression patterns of HDACs and found that, among zinc-dependent HDACs, HDAC2/4/5 were upregulated in the kidney from streptozotocin-induced diabetic rats, diabetic db/db mice, and in kidney biopsies from diabetic patients. Podocytes treated with high glucose, advanced glycation end products, or transforming growth factor-β (common detrimental factors in diabetic nephropathy) selectively increased HDAC4 expression. The role of HDAC4 was evaluated by in vivo gene silencing by intrarenal lentiviral gene delivery and found to reduce renal injury in diabetic rats. Podocyte injury was associated with suppressing autophagy and exacerbating inflammation by HDAC4-STAT1 signaling in vitro. Thus, HDAC4 contributes to podocyte injury and is one of critical components of a signal transduction pathway that links renal injury to autophagy in diabetic nephropathy.

The combination of HDAC and aminopeptidase inhibitors is highly synergistic in myeloma and leads to disruption of the NFκB signalling pathway

PubMed Central

Smith, Emma M.; Zhang, Lei; Walker, Brian A.; Davenport, Emma L.; Aronson, Lauren I.; Krige, David; Hooftman, Leon; Drummond, Alan H.; Morgan, Gareth J.; Davies, Faith E.

2015-01-01

There is a growing body of evidence supporting the use of epigenetic therapies in the treatment of multiple myeloma. We show the novel HDAC inhibitor CHR-3996 induces apoptosis in myeloma cells at concentrations in the nanomolar range and with apoptosis mediated by p53 and caspase pathways. In addition, HDAC inhibitors are highly synergistic, both in vitro and in vivo, with the aminopeptidase inhibitor tosedostat (CHR-2797). We demonstrate that the basis for this synergy is a consequence of changes in the levels of NFκB regulators BIRC3/cIAP2, A20, CYLD, and IκB, which were markedly affected by the combination. When co-administered the HDAC and aminopeptidase inhibitors caused rapid nuclear translocation of NFκB family members p65 and p52, following activation of both canonical and non-canonical NFκB signalling pathways. The subsequent up-regulation of inhibitors of NFκB activation (most significantly BIRC3/cIAP2) turned off the cytoprotective effects of the NFκB signalling response in a negative feedback loop. These results provide a rationale for combining HDAC and aminopeptidase inhibitors clinically for the treatment of myeloma patients and support the disruption of the NFκB signalling pathway as a therapeutic strategy. PMID:26015393

An HDAC3-PROX1 corepressor module acts on HNF4α to control hepatic triglycerides.

PubMed

Armour, Sean M; Remsberg, Jarrett R; Damle, Manashree; Sidoli, Simone; Ho, Wesley Y; Li, Zhenghui; Garcia, Benjamin A; Lazar, Mitchell A

2017-09-15

The histone deacetylase HDAC3 is a critical mediator of hepatic lipid metabolism, and liver-specific deletion of HDAC3 leads to fatty liver. To elucidate the underlying mechanism, here we report a method of cross-linking followed by mass spectrometry to define a high-confidence HDAC3 interactome in vivo that includes the canonical NCoR-HDAC3 complex as well as Prospero-related homeobox 1 protein (PROX1). HDAC3 and PROX1 co-localize extensively on the mouse liver genome, and are co-recruited by hepatocyte nuclear factor 4α (HNF4α). The HDAC3-PROX1 module controls the expression of a gene program regulating lipid homeostasis, and hepatic-specific ablation of either component increases triglyceride content in liver. These findings underscore the importance of specific combinations of transcription factors and coregulators in the fine tuning of organismal metabolism.HDAC3 is a critical mediator of hepatic lipid metabolism and its loss leads to fatty liver. Here, the authors characterize the liver HDAC3 interactome in vivo, provide evidence that HDAC3 interacts with PROX1, and show that HDAC3 and PROX1 control expression of genes regulating lipid homeostasis.

Expression patterns of histone deacetylases in experimental stroke and potential targets for neuroprotection.

PubMed

Chen, Yan-Ting; Zang, Xue-Feng; Pan, Jie; Zhu, Xiao-Lei; Chen, Fei; Chen, Zhi-Bin; Xu, Yun

2012-09-01

1. Histone deacetylase (HDAC) inhibitors exert neuroprotection in both cellular and animal models of ischaemic stroke. However, which HDAC isoform (or isoforms) mediates this beneficial effect has not yet been determined. 2. In the present study, gene levels of the HDAC isoforms were determined in the mouse cortex using reverse transcription-polymerase chain reaction (RT-PCR), whereas changes in the expression of individual zinc-dependent HDAC family members were evaluated by western blotting, 3, 12, 24 and 48 h after cerebral ischaemia induced by transient middle cerebral artery occlusion in male Kunming mice. 3. The HDAC isoforms HDAC1-11 were all expressed in the mouse cortex and differentially affected by cerebral ischaemia. Notably, there was a substantial increase in HDAC3, HDAC6 and HDAC11 expression during the early phases of experimental stroke, indicating their contribution to stroke pathogenesis. Furthermore, induction of HDAC3 and HDAC6 in cortical neurons by ischaemic stroke was confirmed in vivo and in vitro using double-labelled immunostaining and RT-PCR, respectively. Therefore, small hairpin (sh) RNAs were used to selectively knock down HDAC3 or HDAC6. This knockdown appreciably promoted the survival of cortical neurons subjected to oxygen and glucose deprivation. 4. The findings of the present study demonstrate the expression patterns of HDAC isoforms during experimental ischaemic stroke. Furthermore, HDAC3 and HDAC6 were identified as potential mediators in the neurotoxicity of ischaemic stroke, suggesting that specific therapeutic approaches may be considered according to HDAC subtype. © 2012 The Authors Clinical and Experimental Pharmacology and Physiology © 2012 Wiley Publishing Asia Pty Ltd.

Haploinsufficiency of HDAC4 Causes Brachydactyly Mental Retardation Syndrome, with Brachydactyly Type E, Developmental Delays, and Behavioral Problems

PubMed Central

Williams, Stephen R.; Aldred, Micheala A.; Der Kaloustian, Vazken M.; Halal, Fahed; Gowans, Gordon; McLeod, D. Ross; Zondag, Sara; Toriello, Helga V.; Magenis, R. Ellen; Elsea, Sarah H.

2010-01-01

Brachydactyly mental retardation syndrome (BDMR) is associated with a deletion involving chromosome 2q37. BDMR presents with a range of features, including intellectual disabilities, developmental delays, behavioral abnormalities, sleep disturbance, craniofacial and skeletal abnormalities (including brachydactyly type E), and autism spectrum disorder. To date, only large deletions of 2q37 have been reported, making delineation of a critical region and subsequent identification of candidate genes difficult. We present clinical and molecular analysis of six individuals with overlapping deletions involving 2q37.3 that refine the critical region, reducing the candidate genes from >20 to a single gene, histone deacetylase 4 (HDAC4). Driven by the distinct hand and foot anomalies and similar cognitive features, we identified other cases with clinical findings consistent with BDMR but without a 2q37 deletion, and sequencing of HDAC4 identified de novo mutations, including one intragenic deletion probably disrupting normal splicing and one intragenic insertion that results in a frameshift and premature stop codon. HDAC4 is a histone deacetylase that regulates genes important in bone, muscle, neurological, and cardiac development. Reportedly, Hdac4−/− mice have severe bone malformations resulting from premature ossification of developing bones. Data presented here show that deletion or mutation of HDAC4 results in reduced expression of RAI1, which causes Smith-Magenis syndrome when haploinsufficient, providing a link to the overlapping findings in these disorders. Considering the known molecular function of HDAC4 and the mouse knockout phenotype, taken together with deletion or mutation of HDAC4 in multiple subjects with BDMR, we conclude that haploinsufficiency of HDAC4 results in brachydactyly mental retardation syndrome. PMID:20691407

Haploinsufficiency of HDAC4 causes brachydactyly mental retardation syndrome, with brachydactyly type E, developmental delays, and behavioral problems.

PubMed

Williams, Stephen R; Aldred, Micheala A; Der Kaloustian, Vazken M; Halal, Fahed; Gowans, Gordon; McLeod, D Ross; Zondag, Sara; Toriello, Helga V; Magenis, R Ellen; Elsea, Sarah H

2010-08-13

Brachydactyly mental retardation syndrome (BDMR) is associated with a deletion involving chromosome 2q37. BDMR presents with a range of features, including intellectual disabilities, developmental delays, behavioral abnormalities, sleep disturbance, craniofacial and skeletal abnormalities (including brachydactyly type E), and autism spectrum disorder. To date, only large deletions of 2q37 have been reported, making delineation of a critical region and subsequent identification of candidate genes difficult. We present clinical and molecular analysis of six individuals with overlapping deletions involving 2q37.3 that refine the critical region, reducing the candidate genes from >20 to a single gene, histone deacetylase 4 (HDAC4). Driven by the distinct hand and foot anomalies and similar cognitive features, we identified other cases with clinical findings consistent with BDMR but without a 2q37 deletion, and sequencing of HDAC4 identified de novo mutations, including one intragenic deletion probably disrupting normal splicing and one intragenic insertion that results in a frameshift and premature stop codon. HDAC4 is a histone deacetylase that regulates genes important in bone, muscle, neurological, and cardiac development. Reportedly, Hdac4(-/-) mice have severe bone malformations resulting from premature ossification of developing bones. Data presented here show that deletion or mutation of HDAC4 results in reduced expression of RAI1, which causes Smith-Magenis syndrome when haploinsufficient, providing a link to the overlapping findings in these disorders. Considering the known molecular function of HDAC4 and the mouse knockout phenotype, taken together with deletion or mutation of HDAC4 in multiple subjects with BDMR, we conclude that haploinsufficiency of HDAC4 results in brachydactyly mental retardation syndrome.

Inhibition of HDAC6 protects against rhabdomyolysis-induced acute kidney injury

PubMed Central

Shi, Yingfeng; Xu, Liuqing; Tang, Jinhua; Fang, Lu; Ma, Shuchen; Ma, Xiaoyan; Nie, Jing; Pi, Xiaoling; Qiu, Andong; Zhuang, Shougang

2017-01-01

Histone deacetylase 6 (HDAC6) inhibition has been reported to protect against ischemic stroke and prolong survival after sepsis in animal models. However, it remains unknown whether HDAC6 inhibition offers a renoprotective effect after acute kidney injury (AKI). In this study, we examined the effect of tubastatin A (TA), a highly selective inhibitor of HDAC6, on AKI in a murine model of glycerol (GL) injection-induced rhabdomyolysis. Following GL injection, the mice developed severe acute tubular injury as indicated by renal dysfunction; expression of neutrophil gelatinase-associated lipocalin (NGAL), an injury marker of renal tubules; and an increase of TdT-mediated dUTP nick-end labeling (TUNEL)-positive tubular cells. These changes were companied by increased HDAC6 expression in the cytoplasm of renal tubular cells. Administration of TA significantly reduced serum creatinine and blood urea nitrogen levels as well as attenuated renal tubular damage in injured kidneys. HDAC6 inhibition also resulted in decreased expression of NGAL, reduced apoptotic cell, and inactivated caspase-3 in the kidney after acute injury. Moreover, injury to the kidney increased phosphorylation of nuclear factor (NF)-κB and expression of multiple cytokines/chemokines including tumor necrotic factor-α and interleukin-6 and monocyte chemoattractant protein-1, as well as macrophage infiltration. Treatment with TA attenuated all those responses. Finally, HDAC6 inhibition reduced the level of oxidative stress by suppressing malondialdehyde (MDA) and preserving expression of superoxide dismutase (SOD) in the injured kidney. Collectively, these data indicate that HDAC6 contributes to the pathogenesis of rhabdomyolysis-induced AKI and suggest that HDAC6 inhibitors have therapeutic potential for AKI treatment. PMID:28052874

Inhibition of HDAC6 protects against rhabdomyolysis-induced acute kidney injury.

PubMed

Shi, Yingfeng; Xu, Liuqing; Tang, Jinhua; Fang, Lu; Ma, Shuchen; Ma, Xiaoyan; Nie, Jing; Pi, Xiaoling; Qiu, Andong; Zhuang, Shougang; Liu, Na

2017-03-01

Histone deacetylase 6 (HDAC6) inhibition has been reported to protect against ischemic stroke and prolong survival after sepsis in animal models. However, it remains unknown whether HDAC6 inhibition offers a renoprotective effect after acute kidney injury (AKI). In this study, we examined the effect of tubastatin A (TA), a highly selective inhibitor of HDAC6, on AKI in a murine model of glycerol (GL) injection-induced rhabdomyolysis. Following GL injection, the mice developed severe acute tubular injury as indicated by renal dysfunction; expression of neutrophil gelatinase-associated lipocalin (NGAL), an injury marker of renal tubules; and an increase of TdT-mediated dUTP nick-end labeling (TUNEL)-positive tubular cells. These changes were companied by increased HDAC6 expression in the cytoplasm of renal tubular cells. Administration of TA significantly reduced serum creatinine and blood urea nitrogen levels as well as attenuated renal tubular damage in injured kidneys. HDAC6 inhibition also resulted in decreased expression of NGAL, reduced apoptotic cell, and inactivated caspase-3 in the kidney after acute injury. Moreover, injury to the kidney increased phosphorylation of nuclear factor (NF)-κB and expression of multiple cytokines/chemokines including tumor necrotic factor-α and interleukin-6 and monocyte chemoattractant protein-1, as well as macrophage infiltration. Treatment with TA attenuated all those responses. Finally, HDAC6 inhibition reduced the level of oxidative stress by suppressing malondialdehyde (MDA) and preserving expression of superoxide dismutase (SOD) in the injured kidney. Collectively, these data indicate that HDAC6 contributes to the pathogenesis of rhabdomyolysis-induced AKI and suggest that HDAC6 inhibitors have therapeutic potential for AKI treatment. Copyright © 2017 the American Physiological Society.

The histone deacetylase HDAC3 is essential for Purkinje cell function, potentially complicating the use of HDAC inhibitors in SCA1

PubMed Central

Venkatraman, Anand; Hu, Yuan-Shih; Didonna, Alessandro; Cvetanovic, Marija; Krbanjevic, Aleksandar; Bilesimo, Patrice; Opal, Puneet

2014-01-01

Spinocerebellar ataxia type 1 (SCA1) is an incurable neurodegenerative disease caused by a pathogenic glutamine repeat expansion in the protein ataxin-1 (ATXN1). One likely mechanism mediating pathogenesis is excessive transcriptional repression induced by the expanded ATXN-1. Because ATXN1 binds HDAC3, a Class I histone deacetylase (HDAC) that we have found to be required for ATXN1-induced transcriptional repression, we tested whether genetically depleting HDAC3 improves the phenotype of the SCA1 knock-in mouse (SCA1154Q/2Q), the most physiologically relevant model of SCA1. Given that HDAC3 null mice are embryonic lethal, we used for our analyses a combination of HDAC3 haploinsufficient and Purkinje cell (PC)-specific HDAC3 null mice. Although deleting a single allele of HDAC3 in the context of SCA1 was insufficient to improve cerebellar and cognitive deficits of the disease, a complete loss of PC HDAC3 was highly deleterious both behaviorally, with mice showing early onset ataxia, and pathologically, with progressive histologic evidence of degeneration. Inhibition of HDAC3 may yet have a role in SCA1 therapy, but our study provides cautionary evidence that this approach could produce untoward effects. Indeed, the neurotoxic consequences of HDAC3 depletion could prove relevant, wherever pharmacologic inhibition of HDAC3 is being contemplated, in disorders ranging from cancer to neurodegeneration. PMID:24594842

Multiple roles of HDAC inhibition in neurodegenerative conditions

PubMed Central

Chuang, De-Maw; Leng, Yan; Marinova, Zoya; Kim, Hyeon-Ju; Chiu, Chi-Tso

2009-01-01

Histone deacetylases (HDACs) play a key role in homeostasis of protein acetylation in histones and other proteins and in regulating fundamental cellular activities such as transcription. Imbalances in protein acetylation levels and dysfunctions in transcription are associated with a wide variety of brain disorders. Treatment with various HDAC inhibitors corrects these deficiencies and has emerged as a promising new strategy for therapeutic intervention in neurodegenerative diseases. Here, we review and discuss intriguing recent developments in the use of HDAC inhibitors to combat neurodegenerative conditions in cellular and disease models. HDAC inhibitors have neuroprotective, neurotrophic and anti-inflammatory properties, and improvements in neurological performance, learning/memory and other disease phenotypes are frequently seen in these models. We discuss the targets and mechanisms underlying these effects of HDAC inhibition and comment on the potential for some HDAC inhibitors to prove clinically effective in treating neurodegenerative disorders. PMID:19775759

Influenza A Virus Dysregulates Host Histone Deacetylase 1 That Inhibits Viral Infection in Lung Epithelial Cells

PubMed Central

Nagesh, Prashanth Thevkar

2016-01-01

ABSTRACT Viruses dysregulate the host factors that inhibit virus infection. Here, we demonstrate that human enzyme, histone deacetylase 1 (HDAC1) is a new class of host factor that inhibits influenza A virus (IAV) infection, and IAV dysregulates HDAC1 to efficiently replicate in epithelial cells. A time-dependent decrease in HDAC1 polypeptide level was observed in IAV-infected cells, reducing to <50% by 24 h of infection. A further depletion (97%) of HDAC1 expression by RNA interference increased the IAV growth kinetics, increasing it by >3-fold by 24 h and by >6-fold by 48 h of infection. Conversely, overexpression of HDAC1 decreased the IAV infection by >2-fold. Likewise, a time-dependent decrease in HDAC1 activity, albeit with slightly different kinetics to HDAC1 polypeptide reduction, was observed in infected cells. Nevertheless, a further inhibition of deacetylase activity increased IAV infection in a dose-dependent manner. HDAC1 is an important host deacetylase and, in addition to its role as a transcription repressor, HDAC1 has been lately described as a coactivator of type I interferon response. Consistent with this property, we found that inhibition of deacetylase activity either decreased or abolished the phosphorylation of signal transducer and activator of transcription I (STAT1) and expression of interferon-stimulated genes, IFITM3, ISG15, and viperin in IAV-infected cells. Furthermore, the knockdown of HDAC1 expression in infected cells decreased viperin expression by 58% and, conversely, the overexpression of HDAC1 increased it by 55%, indicating that HDAC1 is a component of IAV-induced host type I interferon antiviral response. IMPORTANCE Influenza A virus (IAV) continues to significantly impact global public health by causing regular seasonal epidemics, occasional pandemics, and zoonotic outbreaks. IAV is among the successful human viral pathogens that has evolved various strategies to evade host defenses, prevent the development of a universal vaccine, and acquire antiviral drug resistance. A comprehensive knowledge of IAV-host interactions is needed to develop a novel and alternative anti-IAV strategy. Host produces a variety of factors that are able to fight IAV infection by employing various mechanisms. However, the full repertoire of anti-IAV host factors and their antiviral mechanisms has yet to be identified. We have identified here a new host factor, histone deacetylase 1 (HDAC1) that inhibits IAV infection. We demonstrate that HDAC1 is a component of host innate antiviral response against IAV, and IAV undermines HDAC1 to limit its role in antiviral response. PMID:26912629

Inhibition of histone deacetylase 3 via RGFP966 facilitates cortical plasticity underlying unusually accurate auditory associative cue memory for excitatory and inhibitory cue-reward associations.

PubMed

Shang, Andrea; Bylipudi, Sooraz; Bieszczad, Kasia M

2018-05-31

Epigenetic mechanisms are key for regulating long-term memory (LTM) and are known to exert control on memory formation in multiple systems of the adult brain, including the sensory cortex. One epigenetic mechanism is chromatin modification by histone acetylation. Blocking the action of histone de-acetylases (HDACs) that normally negatively regulate LTM by repressing transcription has been shown to enable memory formation. Indeed, HDAC inhibition appears to facilitate memory by altering the dynamics of gene expression events important for memory consolidation. However, less understood are the ways in which molecular-level consolidation processes alter subsequent memory to enhance storage or facilitate retrieval. Here we used a sensory perspective to investigate whether the characteristics of memory formed with HDAC inhibitors are different from naturally-formed memory. One possibility is that HDAC inhibition enables memory to form with greater sensory detail than normal. Because the auditory system undergoes learning-induced remodeling that provides substrates for sound-specific LTM, we aimed to identify behavioral effects of HDAC inhibition on memory for specific sound features using a standard model of auditory associative cue-reward learning, memory, and cortical plasticity. We found that three systemic post-training treatments of an HDAC3-inhibitor (RGPF966, Abcam Inc.) in rats in the early phase of training facilitated auditory discriminative learning, changed auditory cortical tuning, and increased the specificity for acoustic frequency formed in memory of both excitatory (S+) and inhibitory (S-) associations for at least 2 weeks. The findings support that epigenetic mechanisms act on neural and behavioral sensory acuity to increase the precision of associative cue memory, which can be revealed by studying the sensory characteristics of long-term associative memory formation with HDAC inhibitors. Published by Elsevier B.V.

HDAC Inhibition and Graft Versus Host Disease

PubMed Central

Choi, Sung; Reddy, Pavan

2011-01-01

Histone deacetylase (HDAC) inhibitors are currently used clinically as anticancer drugs. Recent data have demonstrated that some of these drugs have potent antiinflammatory or immunomodulatory effects at noncytotoxic doses. The immunomodulatory effects have shown potential for therapeutic benefit after allogeneic bone marrow transplantation in several experimental models of graft versus host disease (GVHD). These effects, at least in part, result from the ability of HDAC inhibitors (HDACi) to suppress the function of host antigen presenting cells such as dendritic cells (DC). HDACi reduce the dendritic cell (DC) responses, in part, by enhancing the expression of indoleamine 2,3-dioxygenase (IDO) in a signal transducer and activator of transcription-3 (STAT-3) dependent manner. They also alter the function of other immune cells such as T regulatory cells and natural killer (NK) cells, which also play important roles in the biology of GVHD. Based on these observations, a clinical trial has been launched to evaluate the impact of HDAC inhibitors on clinical GVHD. The experimental, mechanistic studies along with the brief preliminary observations from the ongoing clinical trial are discussed in this review. PMID:21298214

Targeting HDAC3, a new partner protein of AKT in the reversal of chemoresistance in acute myeloid leukemia via DNA damage response.

PubMed

Long, J; Fang, W Y; Chang, L; Gao, W H; Shen, Y; Jia, M Y; Zhang, Y X; Wang, Y; Dou, H B; Zhang, W J; Zhu, J; Liang, A B; Li, J M; Hu, Jiong

2017-12-01

Resistance to cytotoxic chemotherapy drugs remains as the major cause of treatment failure in acute myeloid leukemia. Histone deacetylases (HDAC) are important regulators to maintain chromatin structure and control DNA damage; nevertheless, how each HDAC regulates genome stability remains unclear, especially under genome stress conditions. Here, we identified a mechanism by which HDAC3 regulates DNA damage repair and mediates resistance to chemotherapy drugs. In addition to inducing DNA damage, chemotherapy drugs trigger upregulation of HDAC3 expression in leukemia cells. Using genetic and pharmacological approaches, we show that HDAC3 contributes to chemotherapy resistance by regulating the activation of AKT, a well-documented factor in drug resistance development. HDAC3 binds to AKT and deacetylates it at the site Lys20, thereby promoting the phosphorylation of AKT. Chemotherapy drug exposure enhances the interaction between HDAC3 and AKT, resulting in decrease in AKT acetylation and increase in AKT phosphorylation. Whereas HDAC3 depletion or inhibition abrogates these responses and meanwhile sensitizes leukemia cells to chemotoxicity-induced apoptosis. Importantly, in vivo HDAC3 suppression reduces leukemia progression and sensitizes MLL-AF9 + leukemia to chemotherapy. Our findings suggest that combination therapy with HDAC3 inhibitor and genotoxic agents may constitute a successful strategy for overcoming chemotherapy resistance.

Computational analysis for selectivity of histone deacetylase inhibitor by replica-exchange umbrella sampling molecular dynamics simulations

NASA Astrophysics Data System (ADS)

Tsukamoto, Shuichiro; Sakae, Yoshitake; Itoh, Yukihiro; Suzuki, Takayoshi; Okamoto, Yuko

2018-03-01

We performed protein-ligand docking simulations with a ligand T247, which has been reported as a selective inhibitor of a histone deacetylase HDAC3, by the replica-exchange umbrella sampling method in order to estimate the free energy profiles along ligand docking pathways of HDAC3-T247 and HDAC2-T247 systems. The simulation results showed that the docked state of the HDAC3-T247 system is more stable than that of the HDAC2-T247 system although the amino-acid sequences and structures of HDAC3 and HDAC2 are very similar. By comparing structures obtained from the simulations of both systems, we found the difference between structures of hydrophobic residues at the entrance of the catalytic site. Moreover, we performed conventional molecular dynamics simulations of HDAC3 and HDAC2 systems without T247, and the results also showed the same difference of the hydrophobic structures. Therefore, we consider that this hydrophobic structure contributes to the stabilization of the docked state of the HDAC3-T247 system. Furthermore, we show that Tyr209, which is one of the hydrophobic residues in HDAC2, plays a key role in the instability from the simulation results of a mutated-HDAC2 system.

HDAC gene expression in pancreatic tumor cell lines following treatment with the HDAC inhibitors panobinostat (LBH589) and trichostatine (TSA).

PubMed

Mehdi, Ouaïssi; Françoise, Silvy; Sofia, Costa Lima; Urs, Giger; Kevin, Zemmour; Bernard, Sastre; Igor, Sielezneff; Anabela, Cordeiro-da-Silva; Dominique, Lombardo; Eric, Mas; Ali, Ouaïssi

2012-01-01

In this study, the effect of LBH589 and trichostatin (TSA), a standard histone deacetylase inhibitor (HDACi) toward the growth of pancreatic cancer cell lines was studied. Thus, we examined for the first time, the HDAC family gene expression levels before and after drug treatment. Several human pancreatic cancer cell lines (Panc-1, BxPC-3, SOJ-6) and a normal human pancreatic duct immortalized epithelial cell line (HPDE/E6E7) were used as target cells. The cell growth was measured by MTT assay, cell cycle alteration, membrane phosphatidylserine exposure, DNA fragmentation, mitochondrial membrane potential loss, RT-PCR and Western blots were done using standard methods. The effect of drugs on tumor growth in vivo was studied using subcutaneous xenograft model. Except in the case of certain HDAC gene/tumor cell line couples: (SIRT1/HPDE-SOJ6/TSA- or LBH589-treated cells; LBH589-treated Panc-1 Cells; HDAC2/BxPC-3/LBH589-treated cells or TSA-treated SOJ-6-1 cells), there were no major significant changes of HDACs genes transcription in cells upon drug treatment. However, significant variation in HDACs and SIRTs protein expression levels could be seen among individual cell samples. The in vivo results showed that LBH589 formulation exhibited similar tumor reduction efficacy as the commercial drug gemcitabine. Our data demonstrate that LBH589 induced the death of pancreatic tumor cell by apoptosis. In line with its in vitro activity, LBH589 achieved a significant reduction in tumor growth in BxPC-3 pancreatic tumor cell line subcutaneous xenograft mouse model. Furthermore, exploring the impact of LBH589 on HDACs encoding genes expression revealed for the first time that some of them, depending on the cell line considered, seem to be regulated during translation. Copyright © 2012 IAP and EPC. Published by Elsevier B.V. All rights reserved.

HDAC3 Is a Critical Negative Regulator of Long-Term Memory Formation

PubMed Central

McQuown, Susan C.; Barrett, Ruth M.; Matheos, Dina P.; Post, Rebecca J.; Rogge, George A.; Alenghat, Theresa; Mullican, Shannon E.; Jones, Steven; Rusche, James R.; Lazar, Mitchell A.; Wood, Marcelo A.

2011-01-01

Gene expression is dynamically regulated by chromatin modifications on histone tails, such as acetylation. In general, histone acetylation promotes transcription, whereas histone deacetylation negatively regulates transcription. The interplay between histone acetyl-transerases and histone deacetylases (HDACs) is pivotal for the regulation of gene expression required for long-term memory processes. Currently, very little is known about the role of individual HDACs in learning and memory. We examined the role of HDAC3 in long-term memory using a combined genetic and pharmacologic approach. We used HDAC3–FLOX genetically modified mice in combination with adeno-associated virus-expressing Cre recombinase to generate focal homozygous deletions of Hdac3 in area CA1 of the dorsal hippocampus. To complement this approach, we also used a selective inhibitor of HDAC3, RGFP136 [N-(6-(2-amino-4-fluorophenylamino)-6-oxohexyl)-4-methylbenzamide]. Immunohistochemistry showed that focal deletion or intrahippocampal delivery of RGFP136 resulted in increased histone acetylation. Both the focal deletion of HDAC3 as well as HDAC3 inhibition via RGFP136 significantly enhanced long-term memory in a persistent manner. Next we examined expression of genes implicated in long-term memory from dorsal hippocampal punches using quantitative reverse transcription-PCR. Expression of nuclear receptor subfamily 4 group A, member 2 (Nr4a2) and c-fos was significantly increased in the hippocampus of HDAC3–FLOX mice compared with wild-type controls. Memory enhancements observed in HDAC3–FLOX mice were abolished by intrahippocampal delivery of Nr4a2 small interfering RNA, suggesting a mechanism by which HDAC3 negatively regulates memory formation. Together, these findings demonstrate a critical role for HDAC3 in the molecular mechanisms underlying long-term memory formation. PMID:21228185

Identification of highly selective and potent histone deacetylase 3 inhibitors using click chemistry-based combinatorial fragment assembly.

PubMed

Suzuki, Takayoshi; Kasuya, Yuki; Itoh, Yukihiro; Ota, Yosuke; Zhan, Peng; Asamitsu, Kaori; Nakagawa, Hidehiko; Okamoto, Takashi; Miyata, Naoki

2013-01-01

To find histone deacetylase 3 (HDAC3)-selective inhibitors, a series of 504 candidates was assembled using "click chemistry", by reacting nine alkynes bearing a zinc-binding group with 56 azide building blocks in the presence of Cu(I) catalyst. Screening of the 504-member triazole library against HDAC3 and other HDAC isozymes led to the identification of potent and selective HDAC3 inhibitors T247 and T326. These compounds showed potent HDAC3 inhibition with submicromolar IC50s, whereas they did not strongly inhibit other isozymes. Compounds T247 and T326 also induced a dose-dependent selective increase of NF-κB acetylation in human colon cancer HCT116 cells, indicating selective inhibition of HDAC3 in the cells. In addition, these HDAC3-selective inhibitors induced growth inhibition of cancer cells, and activated HIV gene expression in latent HIV-infected cells. These findings indicate that HDAC3-selective inhibitors are promising candidates for anticancer drugs and antiviral agents. This work also suggests the usefulness of the click chemistry approach to find isozyme-selective HDAC inhibitors.

Identification and Structure-Activity Relationship of HDAC6 Zinc-Finger Ubiquitin Binding Domain Inhibitors.

PubMed

Ferreira de Freitas, Renato; Harding, Rachel J; Franzoni, Ivan; Ravichandran, Mani; Mann, Mandeep K; Ouyang, Hui; Lautens, Mark; Santhakumar, Vijayaratnam; Arrowsmith, Cheryl H; Schapira, Matthieu

2018-05-24

HDAC6 plays a central role in the recruitment of protein aggregates for lysosomal degradation and is a promising target for combination therapy with proteasome inhibitors in multiple myeloma. Pharmacologically displacing ubiquitin from the zinc-finger ubiquitin-binding domain (ZnF-UBD) of HDAC6 is an underexplored alternative to catalytic inhibition. Here, we present the discovery of an HDAC6 ZnF-UBD-focused chemical series and its progression from virtual screening hits to low micromolar inhibitors. A carboxylate mimicking the C-terminal extremity of ubiquitin, and an extended aromatic system stacking with W1182 and R1155, are necessary for activity. One of the compounds induced a conformational remodeling of the binding site where the primary binding pocket opens up onto a ligand-able secondary pocket that may be exploited to increase potency. The preliminary structure-activity relationship accompanied by nine crystal structures should enable further optimization into a chemical probe to investigate the merit of targeting the ZnF-UBD of HDAC6 in multiple myeloma and other diseases.

Autotaxin is induced by TSA through HDAC3 and HDAC7 inhibition and antagonizes the TSA-induced cell apoptosis

PubMed Central

2011-01-01

Background Autotaxin (ATX) is a secreted glycoprotein with the lysophospholipase D (lysoPLD) activity to convert lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a bioactive lysophospholipid involved in diverse biological actions. ATX is highly expressed in some cancer cells and contributes to their tumorigenesis, invasion, and metastases, while in other cancer cells ATX is silenced or expressed at low level. The mechanism of ATX expression regulation in cancer cells remains largely unknown. Results In the present study, we demonstrated that trichostatin A (TSA), a well-known HDAC inhibitor (HDACi), significantly induced ATX expression in SW480 and several other cancer cells with low or undetectable endogenous ATX expression. ATX induction could be observed when HDAC3 and HDAC7 were down-regulated by their siRNAs. It was found that HDAC7 expression levels were low in the cancer cells with high endogenous ATX expression. Exogenous over-expression of HDAC7 inhibited ATX expression in these cells in a HDAC3-dependent manner. These data indicate that HDAC3 and HDAC7 collaboratively suppress ATX expression in cancer cells, and suggest that TSA induce ATX expression by inhibiting HDAC3 and HDAC7. The biological significance of this regulation mechanism was revealed by demonstrating that TSA-induced ATX protected cancer cells against TSA-induced apoptosis by producing LPA through its lysoPLD activity, which could be reversed by BrP-LPA and S32826, the inhibitors of the ATX-LPA axis. Conclusions We have demonstrated that ATX expression is repressed by HDAC3 and HDAC7 in cancer cells. During TSA treatment, ATX is induced due to the HDAC3 and HDAC7 inhibition and functionally antagonizes the TSA-induced apoptosis. These results reveal an internal HDACi-resistant mechanism in cancer cells, and suggest that the inhibition of ATX-LPA axis would be helpful to improve the efficacy of HDACi-based therapeutics against cancer. PMID:21314984

Autotaxin is induced by TSA through HDAC3 and HDAC7 inhibition and antagonizes the TSA-induced cell apoptosis.

PubMed

Li, Song; Wang, Baolu; Xu, Yan; Zhang, Junjie

2011-02-12

Autotaxin (ATX) is a secreted glycoprotein with the lysophospholipase D (lysoPLD) activity to convert lysophosphatidylcholine (LPC) into lysophosphatidic acid (LPA), a bioactive lysophospholipid involved in diverse biological actions. ATX is highly expressed in some cancer cells and contributes to their tumorigenesis, invasion, and metastases, while in other cancer cells ATX is silenced or expressed at low level. The mechanism of ATX expression regulation in cancer cells remains largely unknown. In the present study, we demonstrated that trichostatin A (TSA), a well-known HDAC inhibitor (HDACi), significantly induced ATX expression in SW480 and several other cancer cells with low or undetectable endogenous ATX expression. ATX induction could be observed when HDAC3 and HDAC7 were down-regulated by their siRNAs. It was found that HDAC7 expression levels were low in the cancer cells with high endogenous ATX expression. Exogenous over-expression of HDAC7 inhibited ATX expression in these cells in a HDAC3-dependent manner. These data indicate that HDAC3 and HDAC7 collaboratively suppress ATX expression in cancer cells, and suggest that TSA induce ATX expression by inhibiting HDAC3 and HDAC7. The biological significance of this regulation mechanism was revealed by demonstrating that TSA-induced ATX protected cancer cells against TSA-induced apoptosis by producing LPA through its lysoPLD activity, which could be reversed by BrP-LPA and S32826, the inhibitors of the ATX-LPA axis. We have demonstrated that ATX expression is repressed by HDAC3 and HDAC7 in cancer cells. During TSA treatment, ATX is induced due to the HDAC3 and HDAC7 inhibition and functionally antagonizes the TSA-induced apoptosis. These results reveal an internal HDACi-resistant mechanism in cancer cells, and suggest that the inhibition of ATX-LPA axis would be helpful to improve the efficacy of HDACi-based therapeutics against cancer.

Selective HDAC Inhibition for the Disruption of Latent HIV-1 Infection

PubMed Central

Barton, Kirston M.; Archin, Nancie M.; Keedy, Kara S.; Espeseth, Amy S.; Zhang, Yan-ling; Gale, Jennifer; Wagner, Florence F.; Holson, Edward B.; Margolis, David M.

2014-01-01

Selective histone deacetylase (HDAC) inhibitors have emerged as a potential anti-latency therapy for persistent human immunodeficiency virus type 1 (HIV-1) infection. We utilized a combination of small molecule inhibitors and short hairpin (sh)RNA-mediated gene knockdown strategies to delineate the key HDAC(s) to be targeted for selective induction of latent HIV-1 expression. Individual depletion of HDAC3 significantly induced expression from the HIV-1 promoter in the 2D10 latency cell line model. However, depletion of HDAC1 or −2 alone or in combination did not significantly induce HIV-1 expression. Co-depletion of HDAC2 and −3 resulted in a significant increase in expression from the HIV-1 promoter. Furthermore, concurrent knockdown of HDAC1, −2, and −3 resulted in a significant increase in expression from the HIV-1 promoter. Using small molecule HDAC inhibitors of differing selectivity to ablate the residual HDAC activity that remained after (sh)RNA depletion, the effect of depletion of HDAC3 was further enhanced. Enzymatic inhibition of HDAC3 with the selective small-molecule inhibitor BRD3308 activated HIV-1 transcription in the 2D10 cell line. Furthermore, ex vivo exposure to BRD3308 induced outgrowth of HIV-1 from resting CD4+ T cells isolated from antiretroviral-treated, aviremic HIV+ patients. Taken together these findings suggest that HDAC3 is an essential target to disrupt HIV-1 latency, and inhibition of HDAC2 may also contribute to the effort to purge and eradicate latent HIV-1 infection. PMID:25136952

Histone deacetylase inhibitors (HDACIs): multitargeted anticancer agents

PubMed Central

Ververis, Katherine; Hiong, Alison; Karagiannis, Tom C; Licciardi, Paul V

2013-01-01

Histone deacetylase (HDAC) inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents) as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza) and depsipeptide (romidepsin, Istodax). More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the advancement of these drugs, especially to facilitate the rational design of HDAC inhibitors that are effective as antineoplastic agents. This review will discuss the use of HDAC inhibitors as multitargeted therapies for malignancy. Further, we outline the pharmacology and mechanisms of action of HDAC inhibitors while discussing the safety and efficacy of these compounds in clinical studies to date. PMID:23459471

Histone deacetylase inhibitors (HDACIs): multitargeted anticancer agents.

PubMed

Ververis, Katherine; Hiong, Alison; Karagiannis, Tom C; Licciardi, Paul V

2013-01-01

Histone deacetylase (HDAC) inhibitors are an emerging class of therapeutics with potential as anticancer drugs. The rationale for developing HDAC inhibitors (and other chromatin-modifying agents) as anticancer therapies arose from the understanding that in addition to genetic mutations, epigenetic changes such as dysregulation of HDAC enzymes can alter phenotype and gene expression, disturb homeostasis, and contribute to neoplastic growth. The family of HDAC inhibitors is large and diverse. It includes a range of naturally occurring and synthetic compounds that differ in terms of structure, function, and specificity. HDAC inhibitors have multiple cell type-specific effects in vitro and in vivo, such as growth arrest, cell differentiation, and apoptosis in malignant cells. HDAC inhibitors have the potential to be used as monotherapies or in combination with other anticancer therapies. Currently, there are two HDAC inhibitors that have received approval from the US FDA for the treatment of cutaneous T-cell lymphoma: vorinostat (suberoylanilide hydroxamic acid, Zolinza) and depsipeptide (romidepsin, Istodax). More recently, depsipeptide has also gained FDA approval for the treatment of peripheral T-cell lymphoma. Many more clinical trials assessing the effects of various HDAC inhibitors on hematological and solid malignancies are currently being conducted. Despite the proven anticancer effects of particular HDAC inhibitors against certain cancers, many aspects of HDAC enzymes and HDAC inhibitors are still not fully understood. Increasing our understanding of the effects of HDAC inhibitors, their targets and mechanisms of action will be critical for the advancement of these drugs, especially to facilitate the rational design of HDAC inhibitors that are effective as antineoplastic agents. This review will discuss the use of HDAC inhibitors as multitargeted therapies for malignancy. Further, we outline the pharmacology and mechanisms of action of HDAC inhibitors while discussing the safety and efficacy of these compounds in clinical studies to date.

Profiling the anti-protozoal activity of anti-cancer HDAC inhibitors against Plasmodium and Trypanosoma parasites.

PubMed

Engel, Jessica A; Jones, Amy J; Avery, Vicky M; Sumanadasa, Subathdrage D M; Ng, Susanna S; Fairlie, David P; Skinner-Adams, Tina; Andrews, Katherine T

2015-12-01

Histone deacetylase (HDAC) enzymes work together with histone acetyltransferases (HATs) to reversibly acetylate both histone and non-histone proteins. As a result, these enzymes are involved in regulating chromatin structure and gene expression as well as other important cellular processes. HDACs are validated drug targets for some types of cancer, with four HDAC inhibitors clinically approved. However, they are also showing promise as novel drug targets for other indications, including malaria and other parasitic diseases. In this study the in vitro activity of four anti-cancer HDAC inhibitors was examined against parasites that cause malaria and trypanosomiasis. Three of these inhibitors, suberoylanilide hydroxamic acid (SAHA; vorinostat(®)), romidepsin (Istodax(®)) and belinostat (Beleodaq(®)), are clinically approved for the treatment of T-cell lymphoma, while the fourth, panobinostat, has recently been approved for combination therapy use in certain patients with multiple myeloma. All HDAC inhibitors were found to inhibit the growth of asexual-stage Plasmodium falciparum malaria parasites in the nanomolar range (IC50 10-200 nM), while only romidepsin was active at sub-μM concentrations against bloodstream form Trypanosoma brucei brucei parasites (IC50 35 nM). The compounds were found to have some selectivity for malaria parasites compared with mammalian cells, but were not selective for trypanosome parasites versus mammalian cells. All compounds caused hyperacetylation of histone and non-histone proteins in P. falciparum asexual stage parasites and inhibited deacetylase activity in P. falciparum nuclear extracts in addition to recombinant PfHDAC1 activity. P. falciparum histone hyperacetylation data indicate that HDAC inhibitors may differentially affect the acetylation profiles of histone H3 and H4.

The discovery of novel HDAC3 inhibitors via virtual screening and in vitro bioassay

PubMed Central

Hu, Huabin; Xue, Wenjie; Wang, Xiang Simon; Wu, Song

2018-01-01

Abstract Histone deacetylase 3 (HDAC3) is a potential target for the treatment of human diseases such as cancers, diabetes, chronic inflammation and neurodegenerative diseases. Previously, we proposed a virtual screening (VS) pipeline named “Hypo1_FRED_SAHA-3” for the discovery of HDAC3 inhibitors (HDAC3Is) and had thoroughly validated it by theoretical calculations. In this study, we attempted to explore its practical utility in a large-scale VS campaign. To this end, we used the VS pipeline to hierarchically screen the Specs chemical library. In order to facilitate compound cherry-picking, we then developed a knowledge-based pose filter (PF) by using our in-house quantitative structure activity relationship- (QSAR-) modelling approach and coupled it with FRED and Autodock Vina. Afterward, we purchased and tested 11 diverse compounds for their HDAC3 inhibitory activity in vitro. The bioassay has identified compound 2 (Specs ID: AN-979/41971160) as a HDAC3I (IC50 = 6.1 μM), which proved the efficacy of our workflow. As a medicinal chemistry study, we performed a follow-up substructure search and identified two more hit compounds of the same chemical type, i.e. 2–1 (AQ-390/42122119, IC50 = 1.3 μM) and 2–2 (AN-329/43450111, IC50 = 12.5 μM). Based on the chemical structures and activities, we have demonstrated the essential role of the capping group in maintaining the activity for this class of HDAC3Is. In addition, we tested the hit compounds for their in vitro activities on other HDACs, including HDAC1, HDAC2, HDAC8, HDAC4 and HDAC6. We have identified these compounds are HDAC1/2/3 selective inhibitors, of which compound 2 show the best selectivity profile. Taken together, the present study is an experimental validation and an update to our earlier VS strategy. The identified hits could be used as starting structures for the development of highly potent and selective HDAC3Is. PMID:29464997

Histone deacetylase 1 is required for the development of the zebrafish inner ear

PubMed Central

He, Yingzi; Tang, Dongmei; Li, Wenyan; Chai, Renjie; Li, Huawei

2016-01-01

Histone deacetylase 1 (HDAC1) has been reported to be important for multiple aspects of normal embryonic development, but little is known about its function in the development of mechanosensory organs. Here, we first confirmed that HDAC1 is expressed in the developing otic vesicles of zebrafish by whole-mount in situ hybridization. Knockdown of HDAC1 using antisense morpholino oligonucleotides in zebrafish embryos induced smaller otic vesicles, abnormal otoliths, malformed or absent semicircular canals, and fewer sensory hair cells. HDAC1 loss of function also caused attenuated expression of a subset of key genes required for otic vesicle formation during development. Morpholino-mediated knockdown of HDAC1 resulted in decreased expression of members of the Fgf family in the otic vesicles, suggesting that HDAC1 is involved in the development of the inner ear through regulation of Fgf signaling pathways. Taken together, our results indicate that HDAC1 plays an important role in otic vesicle formation. PMID:26832938

Histone deacetylase 3 is required for maintenance of bone mass during aging

PubMed Central

McGee-Lawrence, Meghan E.; Bradley, Elizabeth W.; Dudakovic, Amel; Carlson, Samuel W.; Ryan, Zachary C.; Kumar, Rajiv; Dadsetan, Mahrokh; Yaszemski, Michael J.; Chen, Qingshan; An, Kai-Nan; Westendorf, Jennifer J.

2012-01-01

Histone deacetylase 3 (Hdac3) is a nuclear enzyme that removes acetyl groups from lysine residues in histones and other proteins to epigenetically regulate gene expression. Hdac3 interacts with bone-related transcription factors and co-factors such as Runx2 and Zfp521, and thus is poised to play a key role in the skeletal system. To understand the role of Hdac3 in osteoblasts and osteocytes, Hdac3 conditional knockout (CKO) mice were created with the Osteocalcin (OCN) promoter driving Cre expression. Hdac3 CKOOCN mice were of normal size and weight, but progressively lost trabecular and cortical bone mass with age. The Hdac3 CKOOCN mice exhibited reduced cortical bone mineralization and material properties and suffered frequent fractures. Bone resorption was lower, not higher, in the Hdac3 CKOOCN mice, suggesting that primary defects in osteoblasts caused the reduced bone mass. Indeed, reductions in bone formation were observed. Osteoblasts and osteocytes from Hdac3 CKOOCN mice showed increased DNA damage and reduced functional activity in vivo and in vitro. Thus, Hdac3 expression in osteoblasts and osteocytes is essential for bone maintenance during aging. PMID:23085085

Histone deacetylase 3 (HDAC 3) as emerging drug target in NF-κB-mediated inflammation

PubMed Central

Leus, Niek G.J.; Zwinderman, Martijn R.H.; Dekker, Frank J.

2016-01-01

Activation of inflammatory gene expression is regulated, among other factors, by post-translational modifications of histone proteins. The most investigated type of histone modifications are lysine acetylations. Histone deacetylases (HDACs) remove acetylations from lysines, thereby influencing (inflammatory) gene expression. Intriguingly, apart from histones, HDACs also target non-histone proteins. The nuclear factor κB (NF-κB) pathway is an important regulator in the expression of numerous inflammatory genes, and acetylation plays a crucial role in regulating its responses. Several studies have shed more light on the role of HDAC 1-3 in inflammation with a particular pro-inflammatory role for HDAC 3. Nevertheless, the HDAC-NF-κB interactions in inflammatory signalling have not been fully understood. An important challenge in targeting the regulatory role of HDACs in the NF-κB pathway is the development of highly potent small molecules that selectively target HDAC iso-enzymes. This review focuses on the role of HDAC 3 in (NF-κB-mediated) inflammation and NF-κB lysine acetylation. In addition, we address the application of frequently used small molecule HDAC inhibitors as an approach to attenuate inflammatory responses, and their potential as novel therapeutics. Finally, recent progress and future directions in medicinal chemistry efforts aimed at HDAC 3-selective inhibitors are discussed. PMID:27371876

Influenza A Virus Dysregulates Host Histone Deacetylase 1 That Inhibits Viral Infection in Lung Epithelial Cells.

PubMed

Nagesh, Prashanth Thevkar; Husain, Matloob

2016-05-01

Viruses dysregulate the host factors that inhibit virus infection. Here, we demonstrate that human enzyme, histone deacetylase 1 (HDAC1) is a new class of host factor that inhibits influenza A virus (IAV) infection, and IAV dysregulates HDAC1 to efficiently replicate in epithelial cells. A time-dependent decrease in HDAC1 polypeptide level was observed in IAV-infected cells, reducing to <50% by 24 h of infection. A further depletion (97%) of HDAC1 expression by RNA interference increased the IAV growth kinetics, increasing it by >3-fold by 24 h and by >6-fold by 48 h of infection. Conversely, overexpression of HDAC1 decreased the IAV infection by >2-fold. Likewise, a time-dependent decrease in HDAC1 activity, albeit with slightly different kinetics to HDAC1 polypeptide reduction, was observed in infected cells. Nevertheless, a further inhibition of deacetylase activity increased IAV infection in a dose-dependent manner. HDAC1 is an important host deacetylase and, in addition to its role as a transcription repressor, HDAC1 has been lately described as a coactivator of type I interferon response. Consistent with this property, we found that inhibition of deacetylase activity either decreased or abolished the phosphorylation of signal transducer and activator of transcription I (STAT1) and expression of interferon-stimulated genes, IFITM3, ISG15, and viperin in IAV-infected cells. Furthermore, the knockdown of HDAC1 expression in infected cells decreased viperin expression by 58% and, conversely, the overexpression of HDAC1 increased it by 55%, indicating that HDAC1 is a component of IAV-induced host type I interferon antiviral response. Influenza A virus (IAV) continues to significantly impact global public health by causing regular seasonal epidemics, occasional pandemics, and zoonotic outbreaks. IAV is among the successful human viral pathogens that has evolved various strategies to evade host defenses, prevent the development of a universal vaccine, and acquire antiviral drug resistance. A comprehensive knowledge of IAV-host interactions is needed to develop a novel and alternative anti-IAV strategy. Host produces a variety of factors that are able to fight IAV infection by employing various mechanisms. However, the full repertoire of anti-IAV host factors and their antiviral mechanisms has yet to be identified. We have identified here a new host factor, histone deacetylase 1 (HDAC1) that inhibits IAV infection. We demonstrate that HDAC1 is a component of host innate antiviral response against IAV, and IAV undermines HDAC1 to limit its role in antiviral response. Copyright © 2016, American Society for Microbiology. All Rights Reserved.

Ginsenoside Rg3 Inhibits Melanoma Cell Proliferation through Down-Regulation of Histone Deacetylase 3 (HDAC3) and Increase of p53 Acetylation

PubMed Central

Shan, Xiu; Fu, Yuan-Shan; Aziz, Faisal; Wang, Xiao-Qi; Yan, Qiu; Liu, Ji-Wei

2014-01-01

Malignant melanoma is an aggressive and deadly form of skin cancer, and despite recent advances in available therapies, is still lacking in completely effective treatments. Rg3, a monomer extracted from ginseng roots, has been attempted for the treatment of many cancers. It is reported that the expressions of histone deacetylase 3 (HDAC3) and p53 acetylation correlate with tumor cell growth. However, the antitumor effect of Rg3 on melanoma and the mechanism by which it regulates HDAC3 expression and p53 acetylation remain unknown. We found high expression of HDAC3 in human melanoma tissues to be significantly correlated to lymph node metastasis and clinical stage of disease (p<0.05). In melanoma cells, Rg3 inhibited cell proliferation and induced G0/G1 cell cycle arrest. Rg3 also decreased the expression of HDAC3 and increased the acetylation of p53 on lysine (k373/k382). Moreover, suppression of HDAC3 by either siRNA or a potent HDAC3 inhibitor (MS-275) inhibited cell proliferation, increased p53 acetylation and transcription activity. In A375 melanoma xenograft studies, we demonstrated that Rg3 and HDAC3 short hairpin RNA (shHDAC3) inhibited the growth of xenograft tumors with down-regulation of HDAC3 expression and up-regulation of p53 acetylation. In conclusion, Rg3 has antiproliferative activity against melanoma by decreasing HDAC3 and increasing acetylation of p53 both in vitro and in vivo. Thus, Rg3 serves as a potential therapeutic agent for the treatment of melanoma. PMID:25521755

Combination of polymorphisms within the HDAC1 and HDAC3 gene predict tumor recurrence in hepatocellular carcinoma patients that have undergone transplant therapy.

PubMed

Yang, Zhe; Zhou, Lin; Wu, Li-Ming; Xie, Hai-Yang; Zhang, Feng; Zheng, Shu-Sen

2010-12-01

Histone deacetylases (HDACs) have been reported to be poor prognostic indicators in patients with cancer. However, no data are available for the role of single nucleotide polymorphism (SNP) of class I HDAC in hepato-cellular carcinoma (HCC). Therefore, we investigated the association of class I HDAC isoforms genomic polymorphisms with risk of HCC and tumor recurrence following liver transplantation (LT). One hundred and ninety-six Chinese subjects consisting of 97 HCC patients and 99 controls were enrolled in this study. Nine polymorphisms of the HDAC1, HDAC2, and HDAC3 gene (rs2530223, rs1741981, rs2547547, rs13204445, rs6568819, rs10499080, rs11741808, rs2475631, rs11391) were examined using Applied Biosystems SNaP-Shot and TaqMan technology. We found no significant difference in genotype frequencies between the HCC cases and controls. In terms of tumor recurrence following LT, patients carrying the T allele of HDAC1 SNP rs1741981 showed a favorable outcome for recurrence free survival when compared with patients homozygous for CC. In addition, the same significant trend was observed in HDAC3 SNP rs2547547. Kaplan-Meier analysis showed that the combination of the T variant allele (CT+TT) of HDAC1 SNP rs1741981 and the homozygous TT variant allele of HDAC3 SNP rs2547547 was the most favorable prognostic factor. The risk for postoperative tumor recurrence was about 2.2-fold lower for patients with this genotype combination compared with carriers of the HDAC1 SNP rs1741981 CC and HDAC3 SNP rs2547547 CT genotype combination (hazard ratio: 2.235, p=0.003). Our data suggest that combined analysis of HDAC1 SNP rs1741981 and HDAC3 SNP rs2547547 may be a potential genetic marker for HCC recurrence in LT patients.

HDAC Inhibitors as Epigenetic Regulators of the Immune System: Impacts on Cancer Therapy and Inflammatory Diseases

PubMed Central

Montgomery, McKale R.; Leyva, Kathryn J.

2016-01-01

Histone deacetylase (HDAC) inhibitors are powerful epigenetic regulators that have enormous therapeutic potential and have pleiotropic effects at the cellular and systemic levels. To date, HDAC inhibitors are used clinically for a wide variety of disorders ranging from hematopoietic malignancies to psychiatric disorders, are known to have anti-inflammatory properties, and are in clinical trials for several other diseases. In addition to influencing gene expression, HDAC enzymes also function as part of large, multisubunit complexes which have many nonhistone targets, alter signaling at the cellular and systemic levels, and result in divergent and cell-type specific effects. Thus, the effects of HDAC inhibitor treatment are too intricate to completely understand with current knowledge but the ability of HDAC inhibitors to modulate the immune system presents intriguing therapeutic possibilities. This review will explore the complexity of HDAC inhibitor treatment at the cellular and systemic levels and suggest strategies for effective use of HDAC inhibitors in biomedical research, focusing on the ability of HDAC inhibitors to modulate the immune system. The possibility of combining the documented anticancer effects and newly emerging immunomodulatory effects of HDAC inhibitors represents a promising new combinatorial therapeutic approach for HDAC inhibitor treatments. PMID:27556043

Histone deacetylase 3 indirectly modulates tubulin acetylation.

PubMed

Bacon, Travis; Seiler, Caroline; Wolny, Marcin; Hughes, Ruth; Watson, Peter; Schwabe, John; Grigg, Ronald; Peckham, Michelle

2015-12-15

Histone deacetylase 3 (HDAC3), a member of the Class I subfamily of HDACs, is found in both the nucleus and the cytoplasm. Its roles in the nucleus have been well characterized, but its cytoplasmic roles are still not elucidated fully. We found that blocking HDAC3 activity using MI192, a compound specific for HDAC3, modulated tubulin acetylation in the human prostate cancer cell line PC3. A brief 1 h treatment of PC3 cells with MI192 significantly increased levels of tubulin acetylation and ablated the dynamic behaviour of microtubules in live cells. siRNA-mediated knockdown (KD) of HDAC3 in PC3 cells, significantly increased levels of tubulin acetylation, and overexpression reduced it. However, the active HDAC3-silencing mediator of retinoic and thyroid receptors (SMRT)-deacetylase-activating domain (DAD) complex did not directly deacetylate tubulin in vitro. These data suggest that HDAC3 indirectly modulates tubulin acetylation. © 2015 Authors.

HDAC1 and HDAC3 underlie dynamic H3K9 acetylation during embryonic neurogenesis and in schizophrenia-like animals.

PubMed

Večeřa, Josef; Bártová, Eva; Krejčí, Jana; Legartová, Soňa; Komůrková, Denisa; Rudá-Kučerová, Jana; Štark, Tibor; Dražanová, Eva; Kašpárek, Tomáš; Šulcová, Alexandra; Dekker, Frank J; Szymanski, Wiktor; Seiser, Christian; Weitzer, Georg; Mechoulam, Raphael; Micale, Vincenzo; Kozubek, Stanislav

2018-01-01

Although histone acetylation is one of the most widely studied epigenetic modifications, there is still a lack of information regarding how the acetylome is regulated during brain development and pathophysiological processes. We demonstrate that the embryonic brain (E15) is characterized by an increase in H3K9 acetylation as well as decreases in the levels of HDAC1 and HDAC3. Moreover, experimental induction of H3K9 hyperacetylation led to the overexpression of NCAM in the embryonic cortex and depletion of Sox2 in the subventricular ependyma, which mimicked the differentiation processes. Inducing differentiation in HDAC1-deficient mouse ESCs resulted in early H3K9 deacetylation, Sox2 downregulation, and enhanced astrogliogenesis, whereas neuro-differentiation was almost suppressed. Neuro-differentiation of (wt) ESCs was characterized by H3K9 hyperacetylation that was associated with HDAC1 and HDAC3 depletion. Conversely, the hippocampi of schizophrenia-like animals showed H3K9 deacetylation that was regulated by an increase in both HDAC1 and HDAC3. The hippocampi of schizophrenia-like brains that were treated with the cannabinoid receptor-1 inverse antagonist AM251 expressed H3K9ac at the level observed in normal brains. Together, the results indicate that co-regulation of H3K9ac by HDAC1 and HDAC3 is important to both embryonic brain development and neuro-differentiation as well as the pathophysiology of a schizophrenia-like phenotype. © 2017 Wiley Periodicals, Inc.

Dietary histone deacetylase inhibitors

PubMed Central

Dashwood, Roderick H.; Ho, Emily

2009-01-01

Sulforaphane (SFN) is an isothiocyanate found in cruciferous vegetables, such as broccoli and broccoli sprouts. This anticarcinogen was first identified as a potent inducer of Phase 2 detoxification enzymes, but evidence is mounting that SFN also acts through epigenetic mechanisms. SFN has been shown to inhibit histone deacetylase (HDAC) activity in human colon and prostate cancer lines, with an increase in global and local histone acetylation status, such as on the promoter regions of P21 and bax genes. SFN also inhibited the growth of prostate cancer xenografts and spontaneous intestinal polyps in mouse models, with evidence for altered histone acetylation and HDAC activities in vivo. In human subjects, a single ingestion of 68 g broccoli sprouts inhibited HDAC activity in circulating peripheral blood mononuclear cells 3-6 h after consumption, with concomitant induction of histone H3 and H4 acetylation. These findings provide evidence that one mechanism of cancer chemoprevention by SFN is via epigenetic changes associated with inhibition of HDAC activity. Other dietary agents such as butyrate, biotin, lipoic acid, garlic organosulfur compounds, and metabolites of vitamin E have structural features compatible with HDAC inhibition. The ability of dietary compounds to de-repress epigenetically silenced genes in cancer cells, and to activate these genes in normal cells, has important implications for cancer prevention and therapy. In a broader context, there is growing interest in dietary HDAC inhibitors and their impact on epigenetic mechanisms affecting other chronic conditions, such as cardiovascular disease, neurodegeneration and aging. PMID:17555985

Novel histone deacetylase inhibitor AR-42 exhibits antitumor activity in pancreatic cancer cells by affecting multiple biochemical pathways.

PubMed

Chen, Yi-Jin; Wang, Wen-Hung; Wu, Wan-Yu; Hsu, Chia-Chi; Wei, Ling-Rung; Wang, Sheng-Fan; Hsu, Ya-Wen; Liaw, Chih-Chuang; Tsai, Wan-Chi

2017-01-01

Pancreatic cancer is one of the most lethal types of cancer with a 5-year survival rate of ~5%. Histone deacetylases (HDACs) participate in many cellular processes, including carcinogenesis, and pharmacological inhibition of HDACs has emerged as a potential therapeutic strategy. In this study, we explored antitumor activity of the novel HDAC inhibitor AR-42 in pancreatic cancer. Human pancreatic cancer cell lines BxPC-3 and PANC-1 were used in this study. Real-time PCR, RT-PCR, and western blotting were employed to investigate expression of specific genes and proteins, respectively. Translocation of apoptosis-inducing factor was investigated by immunofluorescence and subcellular fractionation. The number of apoptotic cells, cell cycle stages, and reactive oxygen species (ROS) generation levels were determined by flow cytometry. Cell invasiveness was examined by the Matrigel invasion assay. Efficacy of AR-42 in vivo was evaluated by utilizing BxPC-3 xenograft mouse model. AR-42 inhibited pancreatic cancer cell proliferation by causing G2/M cell cycle arrest via regulating expression levels of genes and proteins involved in cell cycle. AR-42 also induced ROS generation and DNA damage, triggering apoptosis of pancreatic cancer cells via both caspase-3-dependent and caspase-3-independent pathways. In addition, AR-42 increased expression levels of negative regulators of p53 (miR-125b, miR-30d, and miR33), which could contribute to lower expression level of mutant p53 in pancreatic cancer cells. Cell invasion assay showed that AR-42 reduced cancer cell aggressiveness and significantly diminished BxPC-3 xenograft tumor growth in vivo. AR-42, a novel HDAC inhibitor, inhibited pancreatic cancer cells by regulating p53 expression, inducing cell cycle arrest, particularly at the G2/M stage, and activating multiple apoptosis pathways. Additionally, AR-42 inhibited cell invasiveness and potently suppressed pancreatic cancer tumors in vivo. We conclude that by virtue of its multiple mechanisms of action, AR-42 possesses a considerable potential as an antitumor agent in pancreatic cancer.

Transport via SLC5A8 with Subsequent Inhibition of Histone Deacetylases HDAC1 and HDAC3 Underlies the Antitumor Activity of 3-Bromopyruvate

PubMed Central

Thangaraju, Muthusamy; Karunakaran, Senthil K.; Itagaki, Shiro; Gopal, Elangovan; Elangovan, Selvakumar; Prasad, Puttur D.; Ganapathy, Vadivel

2009-01-01

Background 3-Bromopyruvate is an alkylating agent with antitumor activity. It is currently believed that blockade of ATP production from glycolysis and mitochondria is the primary mechanism responsible for this antitumor effect. The present studies have uncovered a new and novel mechanism for the antitumor activity of 3-bromopyruvate. Methods Transport of 3-bromopyruvate via SLC5A8, a tumor suppressor and a Na+-coupled electrogenic transporter for short-chain monocarboxylates, was studied using a mammalian cell expression and the Xenopus laevis oocyte expression systems. The effect of 3-bromopyruvate on histone deacetylases (HDACs) was monitored using the lysate of the human breast cancer cell line MCF7 and human recombinant HDAC isoforms as the enzyme sources. Cell viability was monitored by FACS analysis and colony formation assay. Acetylation status of histone H4 was evaluated by Western blot. Results 3-Bromopyruvate is a transportable substrate for SLC5A8, with the transport process being Na+-coupled and electrogenic. MCF7 cells do not express SLC5A8 and are not affected by 3-bromopyruvate. However, when transfected with SLC5A8 or treated with inhibitors of DNA methylation, these cells undergo apoptosis in the presence of 3-bromopyruvate. This cell death is associated with inhibition of HDAC1/HDAC3. Studies with different isoforms of human recombinant HDACs identify HDAC1 and HDAC3 as the targets for 3-bromopyruvate. Conclusions 3-Bromopyruvate is transported into cells actively via the tumor suppressor SLC5A8 and the process is energized by an electrochemical Na+ gradient. Ectopic expression of the transporter in MCF7 cells leads to apoptosis, and the mechanism involves inhibition of HDAC1/HDAC3. PMID:19637353

The relationship between cisplatin resistance and histone deacetylase isoform overexpression in epithelial ovarian cancer cell lines

PubMed Central

Kim, Min-Gyun; Pak, Jhang Ho; Choi, Won Ho; Park, Jeong-Yeol; Nam, Joo-Hyun

2012-01-01

Objective To investigate the relationship between cisplatin resistance and histone deacetylase (HDAC) isoform overexpression in ovarian cancer cell lines. Methods Expression of four HDAC isoforms (HDAC 1, 2, 3, and 4) in two ovarian cancer cell lines, SKOV3 and OVCAR3, exposed to various concentrations of cisplatin was examined by western blot analyses. Cells were transfected with plasmid DNA of each HDAC. The overexpression of protein and mRNA of each HDAC was confirmed by western blot and reverse transcriptase-polymerase chain reaction analyses, respectively. The cell viability of the SKOV3 and OVCAR3 cells transfected with HDAC plasmid DNA was measured using the cell counting kit-8 assay after treatment with cisplatin. Results The 50% inhibitory concentration of the SKOV3 and OVCAR3 cells can be determined 15-24 hours after treatment with 15 µg/mL cisplatin. The expression level of acetylated histone 3 protein in SKOV3 cells increased after exposure to cisplatin. Compared with control cells at 24 hours after cisplatin exposure, the viability of SKOV3 cells overexpressing HDAC 1 and 3 increased by 15% and 13% (p<0.05), respectively. On the other hand, OVCAR3 cells that overexpressed HDAC 2 and 4 exhibited increased cell viability by 23% and 20% (p<0.05), respectively, compared with control cells 24 hours after exposure to cisplatin. Conclusion In SKOV3 and OVCAR3 epithelial ovarian cancer cell lines, the correlation between HDAC overexpression and cisplatin resistance was confirmed. However, the specific HDAC isoform associated with resistance to cisplatin varied depending on the ovarian cancer cell line. These results may suggest that each HDAC isoform conveys cisplatin resistance via different mechanisms. PMID:22808361

Deacetylase activity of histone deacetylase 3 is required for productive VDJ recombination and B-cell development

PubMed Central

Stengel, Kristy R.; Barnett, Kelly R.; Wang, Jing; Liu, Qi; Hodges, Emily; Hiebert, Scott W.; Bhaskara, Srividya

2017-01-01

Histone deacetylase 3 (HDAC3) is the catalytic component of NCoR/SMRT corepressor complexes that mediate the actions of transcription factors implicated in the regulation of B-cell development and function. We crossed Hdac3 conditional knockout mice with Mb1-Cre knockin animals to delete Hdac3 in early progenitor B cells. The spleens of Hdac3F/−Mb1-Cre+/− mice were virtually devoid of mature B cells, and B220+CD43+ B-cell progenitors accumulated within the bone marrow. Quantitative deep sequencing of the Ig heavy chain locus from B220+CD43+ populations identified a defect in VHDJH recombination with a severe reduction in productive rearrangements, which directly corresponded to the loss of pre-B cells from Hdac3Δ/− bone marrow. For Hdac3Δ/− B cells that did show productive VDJ rearrangement, there was significant skewing toward the incorporation of proximal VH gene segments and a corresponding reduction in distal VH gene segment use. Although transcriptional effects within these loci were modest, Hdac3Δ/− progenitor cells displayed global changes in chromatin structure that likely hindered effective distal V-DJ recombination. Reintroduction of wild-type Hdac3 restored normal B-cell development, whereas an Hdac3 point mutant lacking deacetylase activity failed to complement this defect. Thus, the deacetylase activity of Hdac3 is required for the generation of mature B cells. PMID:28739911

Inhibition of class IIa histone deacetylase activity by gallic acid, sulforaphane, TMP269, and panobinostat.

PubMed

Choi, Sin Young; Kee, Hae Jin; Jin, Li; Ryu, Yuhee; Sun, Simei; Kim, Gwi Ran; Jeong, Myung Ho

2018-05-01

Histone deacetylase (HDAC) inhibitors are gaining increasing attention as potential therapeutics for cardiovascular diseases as well as cancer. We recently reported that the class II HDAC inhibitor, MC1568, and the phytochemical, gallic acid, lowered high blood pressure in mouse models of hypertension. We hypothesized that class II HDACs may be involved in the regulation of hypertension. The aim of this study was to determine and compare the effects of well-known HDAC inhibitors (TMP269, panobinostat, and MC1568), phytochemicals (gallic acid, sulforaphane, and piceatannol), and anti-hypertensive drugs (losartan, carvedilol, and furosemide) on activities of class IIa HDACs (HDAC4, 5, 7, and 9). The selective class IIa HDAC inhibitor, TMP269, and the pan-HDAC inhibitor, panobinostat, but not MC1568, clearly inhibited class IIa HDAC activities. Among the three phytochemicals, gallic acid showed remarkable inhibition, whereas sulforaphane presented mild inhibition of class IIa HDACs. Piceatannol inhibited only HDAC7 activity. As expected, the anti-hypertensive drugs losartan, carvedilol, and furosemide did not affect the activity of any class IIa HDAC. In addition, we evaluated the inhibitory effect of several compounds on the activity of class l HDACs (HDAC1, 2, 3, and 8) and class IIb HDAC (HDAC6). MC1568 did not affect the activities of HDAC1, HDAC2, and HDAC3, but it reduced the activity of HDAC8 at concentrations of 1 and 10 μM. Gallic acid weakly inhibited HDAC1 and HDAC6 activities, but strongly inhibited HDAC8 activity with effectiveness comparable to that of trichostatin A. Inhibition of HDAC2 activity by sulforaphane was stronger than that by piceatnnaol. These results indicated that gallic acid is a powerful dietary inhibitor of HDAC8 and class IIa/b HDAC activities. Sulforaphane may also be used as a dietary inhibitor of HDAC2 and class IIa HDAC. Our findings suggest that the class II HDAC inhibitor, MC1568, does not inhibit class IIa HDAC, but inhibits HDAC8. Copyright © 2018 Elsevier Masson SAS. All rights reserved.

Lithium Down-regulates Histone Deacetylase 1 (HDAC1) and Induces Degradation of Mutant Huntingtin*

PubMed Central

Wu, Shuai; Zheng, Shui-Di; Huang, Hong-Ling; Yan, Li-Chong; Yin, Xiao-Fei; Xu, Hai-Neng; Zhang, Kang-Jian; Gui, Jing-Hua; Chu, Liang; Liu, Xin-Yuan

2013-01-01

Lithium is an effective mood stabilizer that has been clinically used to treat bipolar disorder for several decades. Recent studies have suggested that lithium possesses robust neuroprotective and anti-tumor properties. Thus far, a large number of lithium targets have been discovered. Here, we report for the first time that HDAC1 is a target of lithium. Lithium significantly down-regulated HDAC1 at the translational level by targeting HDAC1 mRNA. We also showed that depletion of HDAC1 is essential for the neuroprotective effects of lithium and for the lithium-mediated degradation of mutant huntingtin through the autophagic pathway. Our studies explain the multiple functions of lithium and reveal a novel mechanism for the function of lithium in neurodegeneration. PMID:24165128

H3K9ac and HDAC2 Activity Are Involved in the Expression of Monocarboxylate Transporter 1 in Oligodendrocyte

PubMed Central

Lai, Qingwei; Du, Wantong; Wu, Jian; Wang, Xiao; Li, Xinyu; Qu, Xuebin; Wu, Xiuxiang; Dong, Fuxing; Yao, Ruiqin; Fan, Hongbin

2017-01-01

Recently, it is reported that monocarboxylate transporter 1 (MCT1) plays crucial role in oligodendrocyte differentiation and myelination. We found that MCT1 is strongly expressed in oligodendrocyte but weakly expressed in oligodendrocyte precursors (OPCs), and the underlying mechanisms remain elusive. Histone deacetylases (HDACs) activity is required for induction of oligodendrocyte differentiation and maturation. We asked whether HDACs are involved in the regulation of MCT1 expression. This work revealed that the acetylation level of histone H3K9 (H3K9ac) was much higher in mct1 gene (Slc16a1) promoter in OPCs than that in oligodendrocyte. H3K9ac regulates MCT1 expression was confirmed by HDAC acetyltransferase inhibitors trichostatin A and curcumin. Of note, there was a negative correlation between H3K9ac and MCT1 expression in oligodendrocyte. Further, we found that the levels of HDAC1, 2, and 3 protein in oligodendrocyte were obviously higher than those in OPCs. However, specific knockdown of HDAC2 but not HDAC1 and HDAC3 significantly decreased the expression of MCT1 in oligodendrocyte. Conversely, overexpression of HDAC2 remarkably enhanced the expression of MCT1. The results imply that HDAC2 is involved in H3K9ac modification which regulates the expression of MCT1 during the development of oligodendrocyte. PMID:29184483

Histone Deacetylase Inhibitors: An Attractive Therapeutic Strategy Against Breast Cancer.

PubMed

Damaskos, Christos; Garmpis, Nikolaos; Valsami, Serena; Kontos, Michael; Spartalis, Eleftherios; Kalampokas, Theodoros; Kalampokas, Emmanouil; Athanasiou, Antonios; Moris, Demetrios; Daskalopoulou, Afrodite; Davakis, Spyridon; Tsourouflis, Gerasimos; Kontzoglou, Konstantinos; Perrea, Despina; Nikiteas, Nikolaos; Dimitroulis, Dimitrios

2017-01-01

With a lifetime risk estimated to be one in eight in industrialized countries, breast cancer is the most frequent type of cancer among women worldwide. Patients are often treated with anti-estrogens, but it is common that some tumors develop resistance to therapy. The causation and progression of cancer is controlled by epigenetic processes, so there is an ongoing interest in research into mechanisms, genes and signaling pathways associating carcinogenesis with epigenetic modulation of gene expression. Given the fact that histone deacetylases (HDACs) have a great impact on chromatin remodeling and epigenetics, their inhibitors have become a very interesting field of research. This review focused on the use of HDAC inhibitors as anticancer treatment and explains the mechanisms of therapeutic effects on breast cancer. We anticipate further clinical benefits of this new class of drugs, both as single agents and in combination therapy. Molecules such as suberoylanilide hydroxamic acid, trichostatin A, suberoylbis-hydroxamic acid, panobinostat, entinostat, valproic acid, sodium butyrate, SK7041, FTY720, N-(2-hydroxyphenyl)-2-propylpentanamide, Scriptaid, YCW1, santacruzamate A and ferrocenyl have shown promising antitumor effects against breast cancer. HDAC inhibitors consists an attractive field for targeted therapy against breast cancer. Future therapeutic strategies will include combination of HDAC inhibitors and chemotherapy or other inhibitors, in order to target multiple oncogenic signaling pathways. More trials are needed. Copyright© 2017 International Institute of Anticancer Research (Dr. John G. Delinassios), All rights reserved.

Histone Deacetylase Inhibitors as Anticancer Drugs.

PubMed

Eckschlager, Tomas; Plch, Johana; Stiborova, Marie; Hrabeta, Jan

2017-07-01

Carcinogenesis cannot be explained only by genetic alterations, but also involves epigenetic processes. Modification of histones by acetylation plays a key role in epigenetic regulation of gene expression and is controlled by the balance between histone deacetylases (HDAC) and histone acetyltransferases (HAT). HDAC inhibitors induce cancer cell cycle arrest, differentiation and cell death, reduce angiogenesis and modulate immune response. Mechanisms of anticancer effects of HDAC inhibitors are not uniform; they may be different and depend on the cancer type, HDAC inhibitors, doses, etc. HDAC inhibitors seem to be promising anti-cancer drugs particularly in the combination with other anti-cancer drugs and/or radiotherapy. HDAC inhibitors vorinostat, romidepsin and belinostat have been approved for some T-cell lymphoma and panobinostat for multiple myeloma. Other HDAC inhibitors are in clinical trials for the treatment of hematological and solid malignancies. The results of such studies are promising but further larger studies are needed. Because of the reversibility of epigenetic changes during cancer development, the potency of epigenetic therapies seems to be of great importance. Here, we summarize the data on different classes of HDAC inhibitors, mechanisms of their actions and discuss novel results of preclinical and clinical studies, including the combination with other therapeutic modalities.

Histone Deacetylase Inhibitors as Anticancer Drugs

PubMed Central

Eckschlager, Tomas; Plch, Johana; Stiborova, Marie; Hrabeta, Jan

2017-01-01

Carcinogenesis cannot be explained only by genetic alterations, but also involves epigenetic processes. Modification of histones by acetylation plays a key role in epigenetic regulation of gene expression and is controlled by the balance between histone deacetylases (HDAC) and histone acetyltransferases (HAT). HDAC inhibitors induce cancer cell cycle arrest, differentiation and cell death, reduce angiogenesis and modulate immune response. Mechanisms of anticancer effects of HDAC inhibitors are not uniform; they may be different and depend on the cancer type, HDAC inhibitors, doses, etc. HDAC inhibitors seem to be promising anti-cancer drugs particularly in the combination with other anti-cancer drugs and/or radiotherapy. HDAC inhibitors vorinostat, romidepsin and belinostat have been approved for some T-cell lymphoma and panobinostat for multiple myeloma. Other HDAC inhibitors are in clinical trials for the treatment of hematological and solid malignancies. The results of such studies are promising but further larger studies are needed. Because of the reversibility of epigenetic changes during cancer development, the potency of epigenetic therapies seems to be of great importance. Here, we summarize the data on different classes of HDAC inhibitors, mechanisms of their actions and discuss novel results of preclinical and clinical studies, including the combination with other therapeutic modalities. PMID:28671573

Histone deacetylase 3 indirectly modulates tubulin acetylation

PubMed Central

Bacon, Travis; Seiler, Caroline; Wolny, Marcin; Hughes, Ruth; Watson, Peter; Schwabe, John; Grigg, Ronald; Peckham, Michelle

2015-01-01

Histone deacetylase 3 (HDAC3), a member of the Class I subfamily of HDACs, is found in both the nucleus and the cytoplasm. Its roles in the nucleus have been well characterized, but its cytoplasmic roles are still not elucidated fully. We found that blocking HDAC3 activity using MI192, a compound specific for HDAC3, modulated tubulin acetylation in the human prostate cancer cell line PC3. A brief 1 h treatment of PC3 cells with MI192 significantly increased levels of tubulin acetylation and ablated the dynamic behaviour of microtubules in live cells. siRNA-mediated knockdown (KD) of HDAC3 in PC3 cells, significantly increased levels of tubulin acetylation, and overexpression reduced it. However, the active HDAC3–silencing mediator of retinoic and thyroid receptors (SMRT)–deacetylase-activating domain (DAD) complex did not directly deacetylate tubulin in vitro. These data suggest that HDAC3 indirectly modulates tubulin acetylation. PMID:26450925

Combinatorial In Silico Strategy towards Identifying Potential Hotspots during Inhibition of Structurally Identical HDAC1 and HDAC2 Enzymes for Effective Chemotherapy against Neurological Disorders

PubMed Central

Ganai, Shabir Ahmad; Abdullah, Ehsaan; Rashid, Romana; Altaf, Mohammad

2017-01-01

Histone deacetylases (HDACs) regulate epigenetic gene expression programs by modulating chromatin architecture and are required for neuronal development. Dysregulation of HDACs and aberrant chromatin acetylation homeostasis have been implicated in various diseases ranging from cancer to neurodegenerative disorders. Histone deacetylase inhibitors (HDACi), the small molecules interfering HDACs have shown enhanced acetylation of the genome and are gaining great attention as potent drugs for treating cancer and neurodegeneration. HDAC2 overexpression has implications in decreasing dendrite spine density, synaptic plasticity and in triggering neurodegenerative signaling. Pharmacological intervention against HDAC2 though promising also targets neuroprotective HDAC1 due to high sequence identity (94%) with former in catalytic domain, culminating in debilitating off-target effects and creating hindrance in the defined intervention. This emphasizes the need of designing HDAC2-selective inhibitors to overcome these vicious effects and for escalating the therapeutic efficacy. Here we report a top-down combinatorial in silico approach for identifying the structural variants that are substantial for interactions against HDAC1 and HDAC2 enzymes. We used extra-precision (XP)-molecular docking, Molecular Mechanics Generalized Born Surface Area (MMGBSA) for predicting affinity of inhibitors against the HDAC1 and HDAC2 enzymes. Importantly, we employed a novel in silico strategy of coupling the state-of-the-art molecular dynamics simulation (MDS) to energetically-optimized structure based pharmacophores (e-Pharmacophores) method via MDS trajectory clustering for hypothesizing the e-Pharmacophore models. Further, we performed e-Pharmacophores based virtual screening against phase database containing millions of compounds. We validated the data by performing the molecular docking and MM-GBSA studies for the selected hits among the retrieved ones. Our studies attributed inhibitor potency to the ability of forming multiple interactions and infirm potency to least interactions. Moreover, our studies delineated that a single HDAC inhibitor portrays differential features against HDAC1 and HDAC2 enzymes. The high affinity and selective HDAC2 inhibitors retrieved through e-Pharmacophores based virtual screening will play a critical role in ameliorating neurodegenerative signaling without hampering the neuroprotective isoform (HDAC1). PMID:29170627

Pharmacophore Based 3D-QSAR, Virtual Screening and Docking Studies on Novel Series of HDAC Inhibitors with Thiophen Linker as Anticancer Agents.

PubMed

Patel, Preeti; Singh, Avineesh; Patel, Vijay K; Jain, Deepak K; Veerasamy, Ravichandran; Rajak, Harish

2016-01-01

Histone deacetylase (HDAC) inhibitors can reactivate gene expression and inhibit the growth and survival of cancer cells. To identify the important pharmacophoric features and correlate 3Dchemical structure with biological activity using 3D-QSAR and Pharmacophore modeling studies. The pharmacophore hypotheses were developed using e-pharmacophore script and phase module. Pharmacophore hypothesis represents the 3D arrangement of molecular features necessary for activity. A series of 55 compounds with wellassigned HDAC inhibitory activity were used for 3D-QSAR model development. Best 3D-QSAR model, which is a five partial least square (PLS) factor model with good statistics and predictive ability, acquired Q2 (0.7293), R2 (0.9811), cross-validated coefficient rcv 2=0.9807 and R2 pred=0.7147 with low standard deviation (0.0952). Additionally, the selected pharmacophore model DDRRR.419 was used as a 3D query for virtual screening against the ZINC database. In the virtual screening workflow, docking studies (HTVS, SP and XP) were carried out by selecting multiple receptors (PDB ID: 1T69, 1T64, 4LXZ, 4LY1, 3MAX, 2VQQ, 3C10, 1W22). Finally, six compounds were obtained based on high scoring function (dock score -11.2278-10.2222 kcal/mol) and diverse structures. The structure activity correlation was established using virtual screening, docking, energetic based pharmacophore modelling, pharmacophore, atom based 3D QSAR models and their validation. The outcomes of these studies could be further employed for the design of novel HDAC inhibitors for anticancer activity.

Regulation of Histone Deacetylase 4 Expression by the SP Family of Transcription FactorsD⃞

PubMed Central

Liu, Fang; Pore, Nabendu; Kim, Mijin; Voong, K. Ranh; Dowling, Melissa; Maity, Amit; Kao, Gary D.

2006-01-01

Histone deacetylases mediate critical cellular functions but relatively little is known about mechanisms controlling their expression, including expression of HDAC4, a class II HDAC implicated in the modulation of cellular differentiation and viability. Endogenous HDAC4 mRNA, protein levels and promoter activity were all readily repressed by mithramycin, suggesting regulation by GC-rich DNA sequences. We validated consensus binding sites for Sp1/Sp3 transcription factors in the HDAC4 promoter through truncation studies and targeted mutagenesis. Specific and functional binding by Sp1/Sp3 at these sites was confirmed with chromatin immunoprecipitation (ChIP) and electromobility shift assays (EMSA). Cotransfection of either Sp1 or Sp3 with a reporter driven by the HDAC4 promoter led to high activities in SL2 insect cells (which lack endogenous Sp1/Sp3). In human cells, restored expression of Sp1 and Sp3 up-regulated HDAC4 protein levels, whereas levels were decreased by RNA-interference-mediated knockdown of either protein. Finally, variable levels of Sp1 were in concordance with that of HDAC4 in a number of human tissues and cancer cell lines. These studies together characterize for the first time the activity of the HDAC4 promoter, through which Sp1 and Sp3 modulates expression of HDAC4 and which may contribute to tissue or cell-line-specific expression of HDAC4. PMID:16280357

Human Cytomegalovirus pUL97 Regulates the Viral Major Immediate Early Promoter by Phosphorylation-Mediated Disruption of Histone Deacetylase 1 Binding

PubMed Central

Bigley, Tarin M.; Reitsma, Justin M.; Mirza, Shama P.

2013-01-01

Human cytomegalovirus (HCMV) is a common agent of congenital infection and causes severe disease in immunocompromised patients. Current approved therapies focus on inhibiting viral DNA replication. The HCMV kinase pUL97 contributes to multiple stages of viral infection including DNA replication, controlling the cell cycle, and virion maturation. Our studies demonstrate that pUL97 also functions by influencing immediate early (IE) gene expression during the initial stages of infection. Inhibition of kinase activity using the antiviral compound maribavir or deletion of the UL97 gene resulted in decreased expression of viral immediate early genes during infection. Expression of pUL97 was sufficient to transactivate IE1 gene expression from the viral genome, which was dependent on viral kinase activity. We observed that pUL97 associates with histone deacetylase 1 (HDAC1). HDAC1 is a transcriptional corepressor that acts to silence expression of viral genes. We observed that inhibition or deletion of pUL97 kinase resulted in increased HDAC1 and decreased histone H3 lysine 9 acetylation associating with the viral major immediate early (MIE) promoter. IE expression during pUL97 inhibition or deletion was rescued following inhibition of deacetylase activity. HDAC1 associates with chromatin by protein-protein interactions. Expression of active but not inactive pUL97 kinase decreased HDAC1 interaction with the transcriptional repressor protein DAXX. Finally, using mass spectrometry, we found that HDAC1 is uniquely phosphorylated upon expression of pUL97. Our results support the conclusion that HCMV pUL97 kinase regulates viral immediate early gene expression by phosphorylation-mediated disruption of HDAC1 binding to the MIE promoter. PMID:23616659

Comparison of the Deacylase and Deacetylase Activity of Zinc-Dependent HDACs.

PubMed

McClure, Jesse J; Inks, Elizabeth S; Zhang, Cheng; Peterson, Yuri K; Li, Jiaying; Chundru, Kalyan; Lee, Bradley; Buchanan, Ashley; Miao, Shiqin; Chou, C James

2017-06-16

The acetylation status of lysine residues on histone proteins has long been attributed to a balance struck between the catalytic activity of histone acetyl transferases and histone deacetylases (HDAC). HDACs were identified as the sole removers of acetyl post-translational modifications (PTM) of histone lysine residues. Studies into the biological role of HDACs have also elucidated their role as removers of acetyl PTMs from lysine residues of nonhistone proteins. These findings, coupled with high-resolution mass spectrometry studies that revealed the presence of acyl-group PTMs on lysine residues of nonhistone proteins, brought forth the possibility of HDACs acting as removers of both acyl- and acetyl-based PTMs. We posited that HDACs fulfill this dual role and sought to investigate their specificity. Utilizing a fluorescence-based assay and biologically relevant acyl-substrates, the selectivities of zinc-dependent HDACs toward these acyl-based PTMs were identified. These findings were further validated using cellular models and molecular biology techniques. As a proof of principal, an HDAC3 selective inhibitor was designed using HDAC3's substrate preference. This resulting inhibitor demonstrates nanomolar activity and >30 fold selectivity toward HDAC3 compared to the other class I HDACs. This inhibitor is capable of increasing p65 acetylation, attenuating NF-κB activation, and thereby preventing downstream nitric oxide signaling. Additionally, this selective HDAC3 inhibition allows for control of HMGB-1 secretion from activated macrophages without altering the acetylation status of histones or tubulin.

Alternative splicing regulated by butyrate in bovine epithelial cells.

PubMed

Wu, Sitao; Li, Congjun; Huang, Wen; Li, Weizhong; Li, Robert W

2012-01-01

As a signaling molecule and an inhibitor of histone deacetylases (HDACs), butyrate exerts its impact on a broad range of biological processes, such as apoptosis and cell proliferation, in addition to its critical role in energy metabolism in ruminants. This study examined the effect of butyrate on alternative splicing in bovine epithelial cells using RNA-seq technology. Junction reads account for 11.28 and 12.32% of total mapped reads between the butyrate-treated (BT) and control (CT) groups. 201,326 potential splicing junctions detected were supported by ≥ 3 junction reads. Approximately 94% of these junctions conformed to the consensus sequence (GT/AG) while ~3% were GC/AG junctions. No AT/AC junctions were observed. A total of 2,834 exon skipping events, supported by a minimum of 3 junction reads, were detected. At least 7 genes, their mRNA expression significantly affected by butyrate, also had exon skipping events differentially regulated by butyrate. Furthermore, COL5A3, which was induced 310-fold by butyrate (FDR <0.001) at the gene level, had a significantly higher number of junction reads mapped to Exon#8 (Donor) and Exon#11 (Acceptor) in BT. This event had the potential to result in the formation of a COL5A3 mRNA isoform with 2 of the 69 exons missing. In addition, 216 differentially expressed transcript isoforms regulated by butyrate were detected. For example, Isoform 1 of ORC1 was strongly repressed by butyrate while Isoform 2 remained unchanged. Butyrate physically binds to and inhibits all zinc-dependent HDACs except HDAC6 and HDAC10. Our results provided evidence that butyrate also regulated deacetylase activities of classical HDACs via its transcriptional control. Moreover, thirteen gene fusion events differentially affected by butyrate were identified. Our results provided a snapshot into complex transcriptome dynamics regulated by butyrate, which will facilitate our understanding of the biological effects of butyrate and other HDAC inhibitors.

Transport by SLC5A8 with subsequent inhibition of histone deacetylase 1 (HDAC1) and HDAC3 underlies the antitumor activity of 3-bromopyruvate.

PubMed

Thangaraju, Muthusamy; Karunakaran, Senthil K; Itagaki, Shiro; Gopal, Elangovan; Elangovan, Selvakumar; Prasad, Puttur D; Ganapathy, Vadivel

2009-10-15

3-bromopyruvate is an alkylating agent with antitumor activity. It is currently believed that blockade of adenosine triphosphate production from glycolysis and mitochondria is the primary mechanism responsible for this antitumor effect. The current studies uncovered a new and novel mechanism for the antitumor activity of 3-bromopyruvate. The transport of 3-bromopyruvate by sodium-coupled monocarboxylate transporter SMCT1 (SLC5A8), a tumor suppressor and a sodium (Na+)-coupled, electrogenic transporter for short-chain monocarboxylates, was studied using a mammalian cell expression and the Xenopus laevis oocyte expression systems. The effect of 3-bromopyruvate on histone deacetylases (HDACs) was monitored using the lysate of the human breast cancer cell line MCF7 and human recombinant HDAC isoforms as the enzyme sources. Cell viability was monitored by fluorescence-activated cell-sorting analysis and colony-formation assay. The acetylation status of histone H4 was evaluated by Western blot analysis. 3-Bromopyruvate is a transportable substrate for SLC5A8, and that transport process is Na+-coupled and electrogenic. MCF7 cells did not express SLC5A8 and were not affected by 3-bromopyruvate. However, when transfected with SLC5A8 or treated with inhibitors of DNA methylation, these cells underwent apoptosis in the presence of 3-bromopyruvate. This cell death was associated with the inhibition of HDAC1/HDAC3. Studies with different isoforms of human recombinant HDACs identified HDAC1 and HDAC3 as the targets for 3-bromopyruvate. 3-Bromopyruvate was transported into cells actively through the tumor suppressor SLC5A8, and the process was energized by an electrochemical Na+ gradient. Ectopic expression of the transporter in MCF7 cells led to apoptosis, and the mechanism involved the inhibition of HDAC1/HDAC3. Copyright (c) 2009 American Cancer Society.

CRISPR screen identifies the NCOR/HDAC3 complex as a major suppressor of differentiation in rhabdomyosarcoma

PubMed Central

Phelps, Michael P.; Bailey, Jenna N.; Vleeshouwer-Neumann, Terra

2016-01-01

Dysregulated gene expression resulting from abnormal epigenetic alterations including histone acetylation and deacetylation has been demonstrated to play an important role in driving tumor growth and progression. However, the mechanisms by which specific histone deacetylases (HDACs) regulate differentiation in solid tumors remains unclear. Using pediatric rhabdomyosarcoma (RMS) as a paradigm to elucidate the mechanism blocking differentiation in solid tumors, we identified HDAC3 as a major suppressor of myogenic differentiation from a high-efficiency Clustered regularly interspaced short palindromic repeats (CRISPR)-based phenotypic screen of class I and II HDAC genes. Detailed characterization of the HDAC3-knockout phenotype in vitro and in vivo using a tamoxifen-inducible CRISPR targeting strategy demonstrated that HDAC3 deacetylase activity and the formation of a functional complex with nuclear receptor corepressors (NCORs) were critical in restricting differentiation in RMS. The NCOR/HDAC3 complex specifically functions by blocking myoblast determination protein 1 (MYOD1)-mediated activation of myogenic differentiation. Interestingly, there was also a transient up-regulation of growth-promoting genes upon initial HDAC3 targeting, revealing a unique cancer-specific response to the forced transition from a neoplastic state to terminal differentiation. Our study applied modifications of CRISPR/CRISPR-associated endonuclease 9 (Cas9) technology to interrogate the function of essential cancer genes and pathways and has provided insights into cancer cell adaptation in response to altered differentiation status. Because current pan-HDAC inhibitors have shown disappointing results in clinical trials of solid tumors, therapeutic targets specific to HDAC3 function represent a promising option for differentiation therapy in malignant tumors with dysregulated HDAC3 activity. PMID:27956629

CRISPR screen identifies the NCOR/HDAC3 complex as a major suppressor of differentiation in rhabdomyosarcoma.

PubMed

Phelps, Michael P; Bailey, Jenna N; Vleeshouwer-Neumann, Terra; Chen, Eleanor Y

2016-12-27

Dysregulated gene expression resulting from abnormal epigenetic alterations including histone acetylation and deacetylation has been demonstrated to play an important role in driving tumor growth and progression. However, the mechanisms by which specific histone deacetylases (HDACs) regulate differentiation in solid tumors remains unclear. Using pediatric rhabdomyosarcoma (RMS) as a paradigm to elucidate the mechanism blocking differentiation in solid tumors, we identified HDAC3 as a major suppressor of myogenic differentiation from a high-efficiency Clustered regularly interspaced short palindromic repeats (CRISPR)-based phenotypic screen of class I and II HDAC genes. Detailed characterization of the HDAC3-knockout phenotype in vitro and in vivo using a tamoxifen-inducible CRISPR targeting strategy demonstrated that HDAC3 deacetylase activity and the formation of a functional complex with nuclear receptor corepressors (NCORs) were critical in restricting differentiation in RMS. The NCOR/HDAC3 complex specifically functions by blocking myoblast determination protein 1 (MYOD1)-mediated activation of myogenic differentiation. Interestingly, there was also a transient up-regulation of growth-promoting genes upon initial HDAC3 targeting, revealing a unique cancer-specific response to the forced transition from a neoplastic state to terminal differentiation. Our study applied modifications of CRISPR/CRISPR-associated endonuclease 9 (Cas9) technology to interrogate the function of essential cancer genes and pathways and has provided insights into cancer cell adaptation in response to altered differentiation status. Because current pan-HDAC inhibitors have shown disappointing results in clinical trials of solid tumors, therapeutic targets specific to HDAC3 function represent a promising option for differentiation therapy in malignant tumors with dysregulated HDAC3 activity.

3-Hydroxypyridin-2-thione as Novel Zinc Binding Group for Selective Histone Deacetylase Inhibition

PubMed Central

Patil, Vishal; Sodji, Quaovi H.; Kornacki, James R.; Mrksich, Milan; Oyelere, Adegboyega K.

2013-01-01

Small molecules bearing hydroxamic acid as the zinc binding group (ZBG) have been the most effective histone deacetylase inhibitor (HDACi) to date. However, concerns about the pharmacokinetic liabilities of the hydroxamic acid moiety have stimulated research efforts aimed at finding alternative non-hydroxamate ZBGs. We have identified 3-hydroxypyridin-2-thione (3-HPT) as a novel ZBG that is compatible with HDAC inhibition. 3-HPT inhibits HDAC 6 and HDAC 8 with an IC50 of 681 nM and 3675 nM respectively. Remarkably, 3-HPT gives no inhibition of HDAC 1. Subsequent optimization led to several novel 3HPT-based HDACi that are selective for HDAC 6 and HDAC 8. Furthermore, a subset of these inhibitors induces apoptosis in various cancer cell lines. PMID:23547652

3-Hydroxypyridin-2-thione as novel zinc binding group for selective histone deacetylase inhibition.

PubMed

Patil, Vishal; Sodji, Quaovi H; Kornacki, James R; Mrksich, Milan; Oyelere, Adegboyega K

2013-05-09

Small molecules bearing hydroxamic acid as the zinc binding group (ZBG) have been the most effective histone deacetylase inhibitors (HDACi) to date. However, concerns about the pharmacokinetic liabilities of the hydroxamic acid moiety have stimulated research efforts aimed at finding alternative nonhydroxamate ZBGs. We have identified 3-hydroxypyridin-2-thione (3-HPT) as a novel ZBG that is compatible with HDAC inhibition. 3-HPT inhibits HDAC 6 and HDAC 8 with an IC50 of 681 and 3675 nM, respectively. Remarkably, 3-HPT gives no inhibition of HDAC 1. Subsequent optimization led to several novel 3HPT-based HDACi that are selective for HDAC 6 and HDAC 8. Furthermore, a subset of these inhibitors induces apoptosis in various cancer cell lines.

Histone deacetylases as targets for treatment of multiple diseases

PubMed Central

TANG, Jinhua; YAN, Haidong; ZHUANG, Shougang

2015-01-01

HDACs (histone deacetylases) are a group of enzymes that deacetylate histones as well as non-histone proteins. They are known as modulators of gene transcription and are associated with proliferation and differentiation of a variety of cell types and the pathogenesis of some diseases. Recently, HDACs have come to be considered crucial targets in various diseases, including cancer, interstitial fibrosis, autoimmune and inflammatory diseases, and metabolic disorders. Pharmacological inhibitors of HDACs have been used or tested to treat those diseases. In the present review, we will examine the application of HDAC inhibitors in a variety of diseases with the focus on their effects of anti-cancer, fibrosis, anti-inflammatory, immunomodulatory activity and regulating metabolic disorders. PMID:23414309

HDAC inhibitors mitigate ischemia-induced oligodendrocyte damage: potential roles of oligodendrogenesis, VEGF, and anti-inflammation

PubMed Central

Kim, Hyeon Ju; Chuang, De-Maw

2014-01-01

White matter injury is an important component of stroke pathology, but its pathophysiology and potential treatment remain relatively elusive and underexplored. We previously reported that after permanent middle cerebral artery occlusion (pMCAO), sodium butyrate (SB) and trichostatin A (TSA) induced neurogenesis via histone deacetylase (HDAC) inhibition in multiple ischemic brain regions in rats; these effects-which depended on activation of brain-derived neurotrophic factor (BDNF)-TrkB signaling-contributed to behavioral improvement. The present study found that SB or TSA robustly protected against ischemia-induced loss of oligodendrocytes detected by confocal microscopy of myelin basic protein (MBP) immunostaining in the ipsilateral subventricular zone (SVZ), striatum, corpus callosum, and frontal cortex seven days post-pMCAO. Co-localization of 5-bromo-2’-deoxyuridine (BrdU)+ and MBP+ cells after SB treatment suggested the occurrence of oligodendrogenesis. SB also strongly upregulated vascular endothelial growth factor (VEGF), which plays a major role in neurogenesis, angiogenesis, and functional recovery after stroke. These SB-induced effects were markedly suppressed by blocking the TrkB signaling pathway with K252a. pMCAO-induced activation of microglia (OX42+) and macrophages/monocytes (ED1+)-which has been linked to white matter injury-was robustly suppressed by SB in a K252a-sensitive manner. In addition, SB treatment largely blocked caspase-3+ and OX42+ cells in ipsilateral brain regions. Our results suggest that HDAC inhibitor-mediated protection against ischemia-induced oligodendrocyte loss may involve multiple mechanisms including oligodendrogenesis, VEGF upregulation, anti-inflammation, and caspase-3 downregulation. Taken together, the results suggest that post-insult treatment with HDAC inhibitors is a rational strategy to mitigate white matter injury following ischemic stroke. PMID:24936215

Class I HDACs control a JIP1-dependent pathway for kinesin-microtubule binding in cardiomyocytes

PubMed Central

Blakeslee, Weston W.; Lin, Ying-Hsi; Stratton, Matthew S.; Tatman, Philip D.; Hu, Tianjing; Ferguson, Bradley S.; McKinsey, Timothy A.

2018-01-01

Class I histone deacetylase (HDAC) inhibitors block hypertrophy and fibrosis of the heart by suppressing pathological signaling and gene expression programs in cardiac myocytes and fibroblasts. The impact of HDAC inhibition in unstressed cardiac cells remains poorly understood. Here, we demonstrate that treatment of cultured cardiomyocytes with small molecule HDAC inhibitors leads to dramatic induction of c-Jun amino-terminal kinase (JNK)-interacting protein-1 (JIP1) mRNA and protein expression. In contrast to prior findings, elevated levels of endogenous JIP1 in cardiomyocytes failed to significantly alter JNK signaling or cardiomyocyte hypertrophy. Instead, HDAC inhibitor-mediated induction of JIP1 was required to stimulate expression of the kinesin heavy chain family member, KIF5A. We provide evidence for an HDAC-dependent regulatory circuit that promotes formation of JIP1:KIF5A:microtubule complexes that regulate intracellular transport of cargo such as autophagosomes. These findings define a novel role for class I HDACs in the control of the JIP1/kinesin axis in cardiomyocytes, and suggest that HDAC inhibitors could be used to alter microtubule transport in the heart. PMID:28886967

A Rational Approach for the Identification of Non-Hydroxamate HDAC6-Selective Inhibitors

NASA Astrophysics Data System (ADS)

Goracci, Laura; Deschamps, Nathalie; Randazzo, Giuseppe Marco; Petit, Charlotte; Dos Santos Passos, Carolina; Carrupt, Pierre-Alain; Simões-Pires, Claudia; Nurisso, Alessandra

2016-07-01

The human histone deacetylase isoform 6 (HDAC6) has been demonstrated to play a major role in cell motility and aggresome formation, being interesting for the treatment of multiple tumour types and neurodegenerative conditions. Currently, most HDAC inhibitors in preclinical or clinical evaluations are non-selective inhibitors, characterised by a hydroxamate zinc-binding group (ZBG) showing off-target effects and mutagenicity. The identification of selective HDAC6 inhibitors with novel chemical properties has not been successful yet, also because of the absence of crystallographic information that makes the rational design of HDAC6 selective inhibitors difficult. Using HDAC inhibitory data retrieved from the ChEMBL database and ligand-based computational strategies, we identified 8 original new non-hydroxamate HDAC6 inhibitors from the SPECS database, with activity in the low μM range. The most potent and selective compound, bearing a hydrazide ZBG, was shown to increase tubulin acetylation in human cells. No effects on histone H4 acetylation were observed. To the best of our knowledge, this is the first report of an HDAC6 selective inhibitor bearing a hydrazide ZBG. Its capability to passively cross the blood-brain barrier (BBB), as observed through PAMPA assays, and its low cytotoxicity in vitro, suggested its potential for drug development.

Design, Multicomponent Synthesis, and Anticancer Activity of a Focused Histone Deacetylase (HDAC) Inhibitor Library with Peptoid-Based Cap Groups.

PubMed

Krieger, Viktoria; Hamacher, Alexandra; Gertzen, Christoph G W; Senger, Johanna; Zwinderman, Martijn R H; Marek, Martin; Romier, Christophe; Dekker, Frank J; Kurz, Thomas; Jung, Manfred; Gohlke, Holger; Kassack, Matthias U; Hansen, Finn K

2017-07-13

In this work, we report the multicomponent synthesis of a focused histone deacetylase (HDAC) inhibitor library with peptoid-based cap groups and different zinc-binding groups. All synthesized compounds were tested in a cellular HDAC inhibition assay and an MTT assay for cytotoxicity. On the basis of their noteworthy activity in the cellular HDAC assays, four compounds were further screened for their inhibitory activity against recombinant HDAC1-3, HDAC6, and HDAC8. All four compounds showed potent inhibition of HDAC1-3 as well as significant inhibition of HDAC6 with IC 50 values in the submicromolar concentration range. Compound 4j, the most potent HDAC inhibitor in the cellular HDAC assay, revealed remarkable chemosensitizing properties and enhanced the cisplatin sensitivity of the cisplatin-resistant head-neck cancer cell line Cal27CisR by almost 7-fold. Furthermore, 4j almost completely reversed the cisplatin resistance in Cal27CisR. This effect is related to a synergistic induction of apoptosis as seen in the combination of 4j with cisplatin.

HDAC11 is a novel drug target in carcinomas.

PubMed

Deubzer, Hedwig E; Schier, Marie C; Oehme, Ina; Lodrini, Marco; Haendler, Bernard; Sommer, Anette; Witt, Olaf

2013-05-01

Inhibition of histone deacetylase (HDAC) activity as stand-alone or combination therapy represents a promising therapeutic approach in oncology. The pan- or class I HDAC inhibitors (HDACi) currently approved or in clinical studies for oncology give rise to dose-limiting toxicities, presumably because of the inhibition of several HDACs. This could potentially be overcome by selective blockade of single HDAC family members. Here we report that HDAC11, the most recently identified zinc-dependent HDAC, is overexpressed in several carcinomas as compared to corresponding healthy tissues. HDAC11 depletion is sufficient to cause cell death and to inhibit metabolic activity in HCT-116 colon, PC-3 prostate, MCF-7 breast and SK-OV-3 ovarian cancer cell lines. The antitumoral effect induced can be mimicked by enforced expression of a catalytically impaired HDAC11 variant, suggesting that inhibition of the enzymatic activity of HDAC11 by small molecules could trigger the desired phenotypic changes. HDAC11 depletion in normal cells causes no changes in metabolic activity and viability, strongly suggesting that tumor-selective effects can be achieved. Altogether, our data show that HDAC11 plays a critical role in cancer cell survival and may represent a novel drug target in oncology. Copyright © 2012 UICC.

Mechanism of Action of 2-Aminobenzamide HDAC Inhibitors in Reversing Gene Silencing in Friedreich’s Ataxia

PubMed Central

Soragni, Elisabetta; Chou, C. James; Rusche, James R.; Gottesfeld, Joel M.

2015-01-01

The genetic defect in Friedreich’s ataxia (FRDA) is the hyperexpansion of a GAA•TTC triplet in the first intron of the FXN gene, encoding the essential mitochondrial protein frataxin. Histone post-translational modifications near the expanded repeats are consistent with heterochromatin formation and consequent FXN gene silencing. Using a newly developed human neuronal cell model, derived from patient-induced pluripotent stem cells, we find that 2-aminobenzamide histone deacetylase (HDAC) inhibitors increase FXN mRNA levels and frataxin protein in FRDA neuronal cells. However, only compounds targeting the class I HDACs 1 and 3 are active in increasing FXN mRNA in these cells. Structural analogs of the active HDAC inhibitors that selectively target either HDAC1 or HDAC3 do not show similar increases in FXN mRNA levels. To understand the mechanism of action of these compounds, we probed the kinetic properties of the active and inactive inhibitors, and found that only compounds that target HDACs 1 and 3 exhibited a slow-on/slow-off mechanism of action for the HDAC enzymes. HDAC1- and HDAC3-selective compounds did not show this activity. Using siRNA methods in the FRDA neuronal cells, we show increases in FXN mRNA upon silencing of either HDACs 1 or 3, suggesting the possibility that inhibition of each of these class I HDACs is necessary for activation of FXN mRNA synthesis, as there appears to be redundancy in the silencing mechanism caused by the GAA•TTC repeats. Moreover, inhibitors must have a long residence time on their target enzymes for this activity. By interrogating microarray data from neuronal cells treated with inhibitors of different specificity, we selected two genes encoding histone macroH2A (H2AFY2) and Polycomb group ring finger 2 (PCGF2) that were specifically down-regulated by the inhibitors targeting HDACs1 and 3 versus the more selective inhibitors for further investigation. Both genes are involved in transcriptional repression and we speculate their involvement in FXN gene silencing. Our results shed light on the mechanism whereby HDAC inhibitors increase FXN mRNA levels in FRDA neuronal cells. PMID:25798128

Evidence for a non-canonical role of HDAC5 in regulation of the cardiac Ncx1 and Bnp genes.

PubMed

Harris, Lillianne G; Wang, Sabina H; Mani, Santhosh K; Kasiganesan, Harinath; Chou, C James; Menick, Donald R

2016-05-05

Class IIa histone deacetylases (HDACs) are very important for tissue specific gene regulation in development and pathology. Because class IIa HDAC catalytic activity is low, their exact molecular roles have not been fully elucidated. Studies have suggested that class IIa HDACs may serve as a scaffold to recruit the catalytically active class I HDAC complexes to their substrate. Here we directly address whether the class IIa HDAC, HDAC5 may function as a scaffold to recruit co-repressor complexes to promoters. We examined two well-characterized cardiac promoters, the sodium calcium exchanger (Ncx1) and the brain natriuretic peptide (Bnp) whose hypertrophic upregulation is mediated by both class I and IIa HDACs. Selective inhibition of class IIa HDACs did not prevent adrenergic stimulated Ncx1 upregulation, however HDAC5 knockout prevented pressure overload induced Ncx1 upregulation. Using the HDAC5((-/-)) mouse we show that HDAC5 is required for the interaction of the HDAC1/2/Sin3a co-repressor complexes with the Nkx2.5 and YY1 transcription factors and critical for recruitment of the HDAC1/Sin3a co-repressor complex to either the Ncx1 or Bnp promoter. Our novel findings support a non-canonical role of class IIa HDACs in the scaffolding of transcriptional regulatory complexes, which may be relevant for therapeutic intervention for pathologies. © The Author(s) 2015. Published by Oxford University Press on behalf of Nucleic Acids Research.

Identification of a Signal-Responsive Nuclear Export Sequence in Class II Histone Deacetylases

PubMed Central

McKinsey, Timothy A.; Zhang, Chun Li; Olson, Eric N.

2001-01-01

Activation of muscle-specific genes by the MEF2 transcription factor is inhibited by class II histone deacetylases (HDACs) 4 and 5, which contain carboxy-terminal deacetylase domains and amino-terminal extensions required for association with MEF2. The inhibitory action of HDACs is overcome by myogenic signals which disrupt MEF2-HDAC interactions and stimulate nuclear export of these transcriptional repressors. Nucleocytoplasmic trafficking of HDAC5 is mediated by binding of the chaperone protein 14-3-3 to two phosphoserine residues (Ser-259 and Ser-498) in its amino-terminal extension. Here we show that HDAC4 and -5 each contain a signal-responsive nuclear export sequence (NES) at their extreme carboxy termini. The NES is conserved in another class II HDAC, HDAC7, but is absent in class I HDACs and the HDAC-related corepressor, MEF2-interacting transcription repressor. Our results suggest that this conserved NES is inactive in unphosphorylated HDAC5, which is localized to the nucleus, and that calcium-calmodulin-dependent protein kinase (CaMK)-dependent binding of 14-3-3 to phosphoserines 259 and 498 activates the NES, with consequent export of the transcriptional repressor to the cytoplasm. A single amino acid substitution in this NES is sufficient to retain HDAC5 in the nucleus in the face of CaMK signaling. These findings provide molecular insight into the mechanism by which extracellular cues alter chromatin structure to promote muscle differentiation and other MEF2-regulated processes. PMID:11509672

CRISPR-mediated HDAC2 disruption identifies two distinct classes of target genes in human cells.

PubMed

Somanath, Priyanka; Herndon Klein, Rachel; Knoepfler, Paul S

2017-01-01

The transcriptional functions of the class I histone deacetylases (HDACs) HDAC1 and HDAC2 are mainly viewed as both repressive and redundant based on murine knockout studies, but they may have additional independent roles and their physiological functions in human cells are not as clearly defined. To address the individual epigenomic functions of HDAC2, here we utilized CRISPR-Cas9 to disrupt HDAC2 in human cells. We find that while HDAC2 null cells exhibited signs of cross-regulation between HDAC1 and HDAC2, specific epigenomic phenotypes were still apparent using RNA-seq and ChIP assays. We identified specific targets of HDAC2 repression, and defined a novel class of genes that are actively expressed in a partially HDAC2-dependent manner. While HDAC2 was required for the recruitment of HDAC1 to repressed HDAC2-gene targets, HDAC2 was dispensable for HDAC1 binding to HDAC2-activated targets, supporting the notion of distinct classes of targets. Both active and repressed classes of gene targets demonstrated enhanced histone acetylation and methylation in HDAC2-null cells. Binding of the HDAC1/2-associated SIN3A corepressor was altered at most HDAC2-targets, but without a clear pattern. Overall, our study defines two classes of HDAC2 targets in human cells, with a dependence of HDAC1 on HDAC2 at one class of targets, and distinguishes unique functions for HDAC2.

Hierarchical virtual screening of the dual MMP-2/HDAC-6 inhibitors from natural products based on pharmacophore models and molecular docking.

PubMed

Wang, Yijun; Yang, Limei; Hou, Jiaying; Zou, Qing; Gao, Qi; Yao, Wenhui; Yao, Qizheng; Zhang, Ji

2018-02-12

The dual-target inhibitors tend to improve the response rate in treating tumors, comparing with the single-target inhibitors. Matrix metalloproteinase-2 (MMP-2) and histone deacetylase-6 (HDAC-6) are attractive targets for cancer therapy. In this study, the hierarchical virtual screening of dual MMP-2/HDAC-6 inhibitors from natural products is investigated. The pharmacophore model of MMP-2 inhibitors is built based on ligands, but the pharmacophore model of HDAC-6 inhibitors is built based on the experimental crystal structures of multiple receptor-ligand complexes. The reliability of these two pharmacophore models is validated subsequently. The hierarchical virtual screening, combining these two different pharmacophore models of MMP-2 and HDAC-6 inhibitors with molecular docking, is carried out to identify the dual MMP-2/HDAC-6 inhibitors from a database of natural products. The four potential dual MMP-2/HDAC-6 inhibitors of natural products, STOCK1 N-46177, STOCK1 N-52245, STOCK1 N-55477, and STOCK1 N-69706, are found. The studies of binding modes show that the screened four natural products can simultaneously well bind with the MMP-2 and HDAC-6 active sites by different kinds of interactions, to inhibit the MMP-2 and HDAC-6 activities. In addition, the ADMET properties of screened four natural products are assessed. These found dual MMP-2/HDAC-6 inhibitors of natural products could serve as the lead compounds for designing the new dual MMP-2/HDAC-6 inhibitors having higher biological activities by carrying out structural modifications and optimizations in the future studies.

The effect of sulforaphane on histone deacetylase activity in keratinocytes: differences between in vitro and in vivo analyses

PubMed Central

Dickinson, Sally E.; Rusche, Jadrian J.; Bec, Sergiu L.; Horn, David J.; Janda, Jaroslav; Rim, So Hyun; Smith, Catharine L.; Bowden, G. Timothy

2015-01-01

Sulforaphane is a natural product found in broccoli which is known to exert many different molecular effects in the cell, including inhibition of histone deacetylase (HDAC) enzymes. Here we examine for the first time the potential for sulforaphane to inhibit HDACs in HaCaT keratinocytes and compare our results with those found using HCT116 colon cancer cells. Significant inhibition of HDAC activity in HCT116 nuclear extracts required prolonged exposure to sulforaphane in the presence of serum. Under the same conditions HaCaT nuclear extracts did not exhibit reduced HDAC activity with sulforaphane treatment. Both cell types displayed down-regulation of HDAC protein levels by sulforaphane treatment. Despite these reductions in HDAC family member protein levels, acetylation of marker proteins (acetylated Histone H3, H4 and tubulin) was decreased by sulforaphane treatment. Timecourse analysis revealed that HDAC6, HDAC3 and acetylated histone H3 protein levels are significantly inhibited as early as 6hr into sulforaphane treatment. Transcript levels of HDAC6 are also suppressed after 48hr of treatment. These results suggest that HDAC activity noted in nuclear extracts is not always translated as expected to target protein acetylation patterns, despite dramatic inhibition of some HDAC protein levels. In addition, our data suggest that keratinocytes are at least partially resistant to the nuclear HDAC inhibitory effects of sulforaphane which is exhibited in HCT116 and other cells. PMID:25307283

A histone deacetylase 3–dependent pathway delimits peripheral myelin growth and functional regeneration

PubMed Central

He, Xuelian; Zhang, Liguo; Queme, Luis F; Liu, Xuezhao; Lu, Andrew; Waclaw, Ronald R; Dong, Xinran; Zhou, Wenhao; Kidd, Grahame; Yoon, Sung-Ok; Buonanno, Andres; Rubin, Joshua B; Xin, Mei; Nave, Klaus-Armin; Trapp, Bruce D; Jankowski, Michael P; Lu, Q Richard

2018-01-01

Deficits in Schwann cell–mediated remyelination impair functional restoration after nerve damage, contributing to peripheral neuropathies. The mechanisms mediating block of remyelination remain elusive. Here, through small-molecule screening focusing on epigenetic modulators, we identified histone deacetylase 3 (HDAC3; a histone-modifying enzyme) as a potent inhibitor of peripheral myelinogenesis. Inhibition of HDAC3 enhanced myelin growth and regeneration and improved functional recovery after peripheral nerve injury in mice. HDAC3 antagonizes the myelinogenic neuregulin–PI3K–AKT signaling axis. Moreover, genome-wide profiling analyses revealed that HDAC3 represses promyelinating programs through epigenetic silencing while coordinating with p300 histone acetyltransferase to activate myelination-inhibitory programs that include the HIPPO signaling effector TEAD4 to inhibit myelin growth. Schwann cell–specific deletion of either Hdac3 or Tead4 in mice resulted in an elevation of myelin thickness in sciatic nerves. Thus, our findings identify the HDAC3–TEAD4 network as a dual-function switch of cell-intrinsic inhibitory machinery that counters myelinogenic signals and maintains peripheral myelin homeostasis, highlighting the therapeutic potential of transient HDAC3 inhibition for improving peripheral myelin repair. PMID:29431744

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nishino, Tomonori G.; Department of Biotechnology, University of Tokyo, Bunkyo-ku, Tokyo 113-8657; Miyazaki, Masaya

Class IIa histone deacetylases (HDACs) form complexes with a class of transcriptional repressors in the nucleus. While screening for compounds that could block the association of HDAC4 with the BTB domain-containing transcriptional repressor Bach2, we discovered that phorbol 12-myristate 13-acetate (PMA) induced the cytoplasmic retention of HDAC4 mutants lacking a nuclear export signal (NES). Although PMA treatment and PKD overexpression has been proposed to facilitate the nuclear export of class IIa HDACs by creating 14-3-3 binding sites containing phosphoserines, our experiments using HDAC mutants demonstrated that PMA greatly reduces nuclear import. PMA treatment repressed the NLS activity in a mannermore » dependent on 14-3-3 binding. These results suggest that nuclear HDAC4 is not tethered in the nucleus, but instead shuttles between the nucleus and the cytoplasm. Phosphorylation-induced 14-3-3 binding biases the balance of nucleo-cytoplasmic shuttling toward the cytoplasm by inhibiting nuclear import.« less

Inhibition of histone deacetylases 1 and 6 enhances cytarabine-induced apoptosis in pediatric acute myeloid leukemia cells.

PubMed

Xu, Xuelian; Xie, Chengzhi; Edwards, Holly; Zhou, Hui; Buck, Steven A; Ge, Yubin

2011-02-16

Pediatric acute myeloid leukemia (AML) remains a challenging disease to treat even with intensified cytarabine-based chemotherapy. Histone deacetylases (HDACs) have been reported to be promising therapeutic targets for treating AML. However, HDAC family members that are involved in chemotherapy sensitivities remain unknown. In this study, we sought to identify members of the HDAC family that are involved in cytarabine sensitivities, and to select the optimal HDACI that is most efficacious when combined with cytarabine for treating children with AML. Expression profiles of classes I, II, and IV HDACs in 4 pediatric AML cell lines were determined by Western blotting. Inhibition of class I HDACs by different HDACIs was measured post immnunoprecipitation. Individual down-regulation of HDACs in pediatric AML cells was performed with lentiviral shRNA. The effects of cytarabine and HDACIs on apoptosis were determined by flow cytometry analysis. Treatments with structurally diverse HDACIs and HDAC shRNA knockdown experiments revealed that down-regulation of both HDACs 1 and 6 is critical in enhancing cytarabine-induced apoptosis in pediatric AML, at least partly mediated by Bim. However, down-regulation of HDAC2 may negatively impact cytarabine sensitivities in the disease. At clinically achievable concentrations, HDACIs that simultaneously inhibited both HDACs 1 and 6 showed the best anti-leukemic activities and significantly enhanced cytarabine-induced apoptosis. Our results further confirm that HDACs are bona fide therapeutic targets for treating pediatric AML and suggest that pan-HDACIs may be more beneficial than isoform-specific drugs.

Insights into structural features of HDAC1 and its selectivity inhibition elucidated by Molecular dynamic simulation and Molecular Docking.

PubMed

Sixto-López, Yudibeth; Bello, Martiniano; Correa-Basurto, José

2018-03-06

Histone deacetylases (HDACs) are a family of proteins whose main function is the removal of acetyl groups from lysine residues located on histone and non-histone substrates, which regulates gene transcription and other activities in cells. HDAC1 dysfunction has been implicated in cancer development and progression; thus, its inhibition has emerged as a new therapeutic strategy. Two additional metal binding sites (Site 1 and Site 2) in HDACs have been described that are primarily occupied by potassium ions, suggesting a possible structural role that affects HDAC activity. In this work, we explored the structural role of potassium ions in Site 1 and Site 2 and how they affect the interactions of compounds with high affinities for HDAC1 (AC1OCG0B, Chlamydocin, Dacinostat and Quisinostat) and SAHA (a pan-inhibitor) using molecular docking and molecular dynamics (MD) simulations in concert with a Molecular-Mechanics-Generalized-Born-Surface-Area (MMGBSA) approach. Four models were generated: one with a potassium ion (K + ) in both sites (HDAC1 k ), a second with K + only at site 1 (HDAC1 ks1 ), a third with K + only at site 2 (HDAC1 ks2 ) and a fourth with no K + (HDAC1 wk ). We found that the presence or absence of K + not only impacted the structural flexibility of HDAC1, but also its molecular recognition, consistent with experimental findings. These results could therefore be useful for further structure-based drug design studies addressing new HDAC1 inhibitors.

Aberrant histone deacetylase2-mediated histone modifications and synaptic plasticity in the amygdala predisposes to anxiety and alcoholism.

PubMed

Moonat, Sachin; Sakharkar, Amul J; Zhang, Huaibo; Tang, Lei; Pandey, Subhash C

2013-04-15

Epigenetic mechanisms have been implicated in psychiatric disorders, including alcohol dependence. However, the epigenetic basis and role of specific histone deacetylase (HDAC) isoforms in the genetic predisposition to anxiety and alcoholism is unknown. We measured amygdaloid HDAC activity, levels of HDAC isoforms, and histone H3 acetylation in selectively bred alcohol-preferring (P) and -nonpreferring (NP) rats. We employed HDAC2 small interfering RNA infusion into the central nucleus of amygdala (CeA) of P rats to determine the causal role of HDAC2 in anxiety-like and alcohol-drinking behaviors. Chromatin immunoprecipitation analysis was performed to examine the histone acetylation status of brain-derived neurotrophic factor (Bdnf) and activity-regulated cytoskeleton associated protein (Arc) genes. Golgi-Cox staining was performed to measure dendritic spine density. We found that P rats innately display higher nuclear HDAC activity and HDAC2 but not HDAC 1, 3, 4, 5, and 6 protein levels and lower acetylation of H3-K9 but not H3-K14, in the CeA and medial nucleus of amygdala compared with NP rats. Acute ethanol exposure decreased amygdaloid HDAC activity and HDAC2 protein levels, increased global and gene (Bdnf and Arc)-specific histone acetylation, and attenuated anxiety-like behaviors in P rats but had no effects in NP rats. The HDAC2 knockdown in the CeA attenuated anxiety-like behaviors and voluntary alcohol but not sucrose consumption in P rats and increased histone acetylation of Bdnf and Arc with a resultant increase in protein levels that correlated with increased dendritic spine density. These novel data demonstrate the role of HDAC2-mediated epigenetic mechanisms in anxiety and alcoholism. Published by Elsevier Inc.

Cyclic phosphatidic acid inhibits alkyl-glycerophosphate-induced downregulation of histone deacetylase 2 expression and suppresses the inflammatory response in human coronary artery endothelial cells.

PubMed

Tsukahara, Tamotsu; Haniu, Hisao; Matsuda, Yoshikazu

2014-01-01

Activation of the endothelium by alkyl-glycerophosphate (AGP) has been implicated in the development of atherosclerosis. Our previous study suggested that cyclic phosphatidic acid (cPA) inhibits arterial wall remodeling in a rat model in vivo. However, the mechanisms through which specific target genes are regulated during this process remain unclear. Here, we examined whether cPA inhibited AGP-induced expression of class I histone deacetylases (HDACs, namely HDAC1, HDAC2, HDAC3, and HDAC8), which may affect subsequent transcriptional activity of target genes. Our experimental results showed that human coronary artery endothelial cells (HCAECs) expressed high levels of HDAC2 and low levels HDAC1, HDAC3, and HDAC8. Moreover, AGP treatment induced downregulation of HDAC2 expression in HCAECs. However, cotreatment with cPA inhibited this downregulation of HDAC2 expression. Interestingly, treatment with AGP increased the expression and secretion of endogenous interleukin (IL)-6 and IL-8; however, this effect was inhibited when HCAECs were cotreated with cPA or the synthetic peroxisome proliferator-activator receptor gamma (PPARγ) antagonist T0070907. Thus, our data suggested that cPA may have beneficial effects in inflammation-related cardiovascular disease by controlling HDAC2 regulation.

Cyclic Phosphatidic Acid Inhibits Alkyl-Glycerophosphate-Induced Downregulation of Histone Deacetylase 2 Expression and Suppresses the Inflammatory Response in Human Coronary Artery Endothelial Cells

PubMed Central

Tsukahara, Tamotsu; Haniu, Hisao; Matsuda, Yoshikazu

2014-01-01

Activation of the endothelium by alkyl-glycerophosphate (AGP) has been implicated in the development of atherosclerosis. Our previous study suggested that cyclic phosphatidic acid (cPA) inhibits arterial wall remodeling in a rat model in vivo. However, the mechanisms through which specific target genes are regulated during this process remain unclear. Here, we examined whether cPA inhibited AGP-induced expression of class I histone deacetylases (HDACs, namely HDAC1, HDAC2, HDAC3, and HDAC8), which may affect subsequent transcriptional activity of target genes. Our experimental results showed that human coronary artery endothelial cells (HCAECs) expressed high levels of HDAC2 and low levels HDAC1, HDAC3, and HDAC8. Moreover, AGP treatment induced downregulation of HDAC2 expression in HCAECs. However, cotreatment with cPA inhibited this downregulation of HDAC2 expression. Interestingly, treatment with AGP increased the expression and secretion of endogenous interleukin (IL)-6 and IL-8; however, this effect was inhibited when HCAECs were cotreated with cPA or the synthetic peroxisome proliferator-activator receptor gamma (PPARγ) antagonist T0070907. Thus, our data suggested that cPA may have beneficial effects in inflammation-related cardiovascular disease by controlling HDAC2 regulation. PMID:25013374

Histone deacetylase inhibitors improve learning consolidation in young and in KA-induced-neurodegeneration and SAMP-8-mutant mice.

PubMed

Fontán-Lozano, Angela; Romero-Granados, Rocío; Troncoso, Julieta; Múnera, Alejandro; Delgado-García, José María; Carrión, Angel M

2008-10-01

Histone deacetylases (HDAC) are enzymes that maintain chromatin in a condensate state, related with absence of transcription. We have studied the role of HDAC on learning and memory processes. Both eyeblink classical conditioning (EBCC) and object recognition memory (ORM) induced an increase in histone H3 acetylation (Ac-H3). Systemic treatment with HDAC inhibitors improved cognitive processes in EBCC and in ORM tests. Immunohistochemistry and gene expression analyses indicated that administration of HDAC inhibitors decreased the stimulation threshold for Ac-H3, and gene expression to reach the levels required for learning and memory. Finally, we evaluated the effect of systemic administration of HDAC inhibitors to mice models of neurodegeneration and aging. HDAC inhibitors reversed learning and consolidation deficits in ORM in these models. These results point out HDAC inhibitors as candidate agents for the palliative treatment of learning and memory impairments in aging and in neurodegenerative disorders.

The effect of sulforaphane on histone deacetylase activity in keratinocytes: Differences between in vitro and in vivo analyses.

PubMed

Dickinson, Sally E; Rusche, Jadrian J; Bec, Sergiu L; Horn, David J; Janda, Jaroslav; Rim, So Hyun; Smith, Catharine L; Bowden, G Timothy

2015-11-01

Sulforaphane is a natural product found in broccoli, which is known to exert many different molecular effects in the cell, including inhibition of histone deacetylase (HDAC) enzymes. Here, we examine for the first time the potential for sulforaphane to inhibit HDACs in HaCaT keratinocytes and compare our results with those found using HCT116 colon cancer cells. Significant inhibition of HDAC activity in HCT116 nuclear extracts required prolonged exposure to sulforaphane in the presence of serum. Under the same conditions HaCaT nuclear extracts did not exhibit reduced HDAC activity with sulforaphane treatment. Both cell types displayed down-regulation of HDAC protein levels by sulforaphane treatment. Despite these reductions in HDAC family member protein levels, acetylation of marker proteins (acetylated Histone H3, H4, and tubulin) was decreased by sulforaphane treatment. Time-course analysis revealed that HDAC6, HDAC3, and acetylated histone H3 protein levels are significantly inhibited as early as 6 h into sulforaphane treatment. Transcript levels of HDAC6 are also suppressed after 48 h of treatment. These results suggest that HDAC activity noted in nuclear extracts is not always translated as expected to target protein acetylation patterns, despite dramatic inhibition of some HDAC protein levels. In addition, our data suggest that keratinocytes are at least partially resistant to the nuclear HDAC inhibitory effects of sulforaphane, which is exhibited in HCT116 and other cells. © 2014 The Authors. Molecular Carcinogenesis published by Wiley Periodicals, Inc.

Immunoexpression of HDAC1, HDAC2, and HAT1 in actinic cheilitis and lip squamous cell carcinoma.

PubMed

Chrun, E S; Modolo, F; Vieira, Dsc; Borges-Júnior, Áls; Castro, R G; Daniel, F I

2017-05-01

Acetylation and deacetylation are the most studied covalent histone modifications resulting in transcriptional regulation with histone deacetylases (HDAC) and histone acetyltransferases (HAT) as the main associated enzymes. These enzymes overexpression induces abnormal transcription of key genes that regulate important cellular functions, such as proliferation, cell cycle regulation, and apoptosis. Thus, the expression of different HATs and HDACs has been evaluated in various cancers. To investigate HDAC1, HDAC2 and HAT1 expression in lip squamous cell carcinoma (LSCC) and actinic cheilitis (AC) and to demonstrate their correlation with DNA metyltransferases (DNMTs). Thirty cases of lip squamous cell carcinoma (LSCC), thirty cases of actinic cheilitis (AC), and 28 cases of non-neoplastic epithelium as control were selected for immunohistochemical investigation. Nuclear HDAC2 immunopositivity was significantly higher in AC (75.07% ± 29.70) when compared with LSCC (51.06% ± 39.02). HDAC1 and HAT1 nuclear immunostaining were higher in AC, with no statistical significance. When comparing data with our previous study, we found a positive correlation between HDAC1 X DNMT1/DNMT3b, HDAC2 X DNMT3b, and HAT1 X DNMT1/DNMT3b for certain studied groups. This study showed higher levels of nuclear HDAC2 immunopositivity in AC, possibly indicating that this enzyme plays a key role in lip photocarcinogenesis early stages. © 2017 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

HDAC3 and the Molecular Brake Pad Hypothesis

PubMed Central

McQuown, Susan C.; Wood, Marcelo A.

2011-01-01

Successful transcription of specific genes required for long-term memory processes involves the orchestrated effort of not only transcription factors, but also very specific enzymatic protein complexes that modify chromatin structure. Chromatin modification has been identified as a pivotal molecular mechanism underlying certain forms of synaptic plasticity and memory. The best-studied form of chromatin modification in the learning and memory field is histone acetylation, which is regulated by histone acetyltransferases and histone deacetylases (HDACs). HDAC inhibitors have been shown to strongly enhance long-term memory processes, and recent work has aimed to identify contributions of individual HDACs. In this review, we focus on HDAC3 and discuss its recently defined role as a negative regulator of long-term memory formation. HDAC3 is part of a corepressor complex and has direct interactions with class II HDACs that may be important for its molecular and behavioral consequences. And last, we propose the “molecular brake pad” hypothesis of HDAC function. The HDACs and associated corepressor complexes may function in neurons, in part, as “molecular brake pads.” HDACs are localized to promoters of active genes and act as a persistent clamp that requires strong activity-dependent signaling to temporarily release these complexes (or brake pads) to activate gene expression required for long-term memory formation. Thus, HDAC inhibition removes the “molecular brake pads” constraining the processes necessary for long-term memory and results in strong, persistent memory formation. PMID:21521655

HDAC7 Ubiquitination by the E3 Ligase CBX4 Is Involved in Contextual Fear Conditioning Memory Formation.

PubMed

Jing, Xu; Sui, Wen-Hai; Wang, Shuai; Xu, Xu-Feng; Yuan, Rong-Rong; Chen, Xiao-Rong; Ma, Hui-Xian; Zhu, Ying-Xiao; Sun, Jin-Kai; Yi, Fan; Chen, Zhe-Yu; Wang, Yue

2017-04-05

Histone acetylation, an epigenetic modification, plays an important role in long-term memory formation. Recently, histone deacetylase (HDAC) inhibitors were demonstrated to promote memory formation, which raises the intriguing possibility that they may be used to rescue memory deficits. However, additional research is necessary to clarify the roles of individual HDACs in memory. In this study, we demonstrated that HDAC7, within the dorsal hippocampus of C57BL6J mice, had a late and persistent decrease after contextual fear conditioning (CFC) training (4-24 h), which was involved in long-term CFC memory formation. We also showed that HDAC7 decreased via ubiquitin-dependent degradation. CBX4 was one of the HDAC7 E3 ligases involved in this process. Nur77, as one of the target genes of HDAC7, increased 6-24 h after CFC training and, accordingly, modulated the formation of CFC memory. Finally, HDAC7 was involved in the formation of other hippocampal-dependent memories, including the Morris water maze and object location test. The current findings facilitate an understanding of the molecular and cellular mechanisms of HDAC7 in the regulation of hippocampal-dependent memory. SIGNIFICANCE STATEMENT The current findings demonstrated the effects of histone deacetylase 7 (HDAC7) on hippocampal-dependent memories. Moreover, we determined the mechanism of decreased HDAC7 in contextual fear conditioning (CFC) through ubiquitin-dependent protein degradation. We also verified that CBX4 was one of the HDAC7 E3 ligases. Finally, we demonstrated that Nur77, as one of the important targets for HDAC7, was involved in CFC memory formation. All of these proteins, including HDAC7, CBX4, and Nur77, could be potential therapeutic targets for preventing memory deficits in aging and neurological diseases. Copyright © 2017 the authors 0270-6474/17/373848-16$15.00/0.

Inhibition of Histone Deacetylases 1 and 6 Enhances Cytarabine-Induced Apoptosis in Pediatric Acute Myeloid Leukemia Cells

PubMed Central

Xu, Xuelian; Xie, Chengzhi; Edwards, Holly; Zhou, Hui; Buck, Steven A.; Ge, Yubin

2011-01-01

Background Pediatric acute myeloid leukemia (AML) remains a challenging disease to treat even with intensified cytarabine-based chemotherapy. Histone deacetylases (HDACs) have been reported to be promising therapeutic targets for treating AML. However, HDAC family members that are involved in chemotherapy sensitivities remain unknown. In this study, we sought to identify members of the HDAC family that are involved in cytarabine sensitivities, and to select the optimal HDACI that is most efficacious when combined with cytarabine for treating children with AML. Methodology Expression profiles of classes I, II, and IV HDACs in 4 pediatric AML cell lines were determined by Western blotting. Inhibition of class I HDACs by different HDACIs was measured post immnunoprecipitation. Individual down-regulation of HDACs in pediatric AML cells was performed with lentiviral shRNA. The effects of cytarabine and HDACIs on apoptosis were determined by flow cytometry analysis. Results Treatments with structurally diverse HDACIs and HDAC shRNA knockdown experiments revealed that down-regulation of both HDACs 1 and 6 is critical in enhancing cytarabine-induced apoptosis in pediatric AML, at least partly mediated by Bim. However, down-regulation of HDAC2 may negatively impact cytarabine sensitivities in the disease. At clinically achievable concentrations, HDACIs that simultaneously inhibited both HDACs 1 and 6 showed the best anti-leukemic activities and significantly enhanced cytarabine-induced apoptosis. Conclusion Our results further confirm that HDACs are bona fide therapeutic targets for treating pediatric AML and suggest that pan-HDACIs may be more beneficial than isoform-specific drugs. PMID:21359182

Combined Treatment with the Mood Stabilizers Lithium and Valproate Produces Multiple Beneficial Effects in Transgenic Mouse Models of Huntington's Disease

PubMed Central

Chiu, Chi-Tso; Liu, Guangping; Leeds, Peter; Chuang, De-Maw

2011-01-01

Emerging evidence suggests that the mood stabilizers lithium and valproate (VPA) have broad neuroprotective and neurotrophic properties, and that these occur via inhibition of glycogen synthase kinase 3 (GSK-3) and histone deacetylases (HDACs), respectively. Huntington's disease (HD) is an inherited neurodegenerative disorder characterized by impaired movement, cognitive and psychiatric disturbances, and premature death. We treated N171-82Q and YAC128 mice, two mouse models of HD varying in genetic backgrounds and pathological progressions, with a diet containing therapeutic doses of lithium, VPA, or both. Untreated, these transgenic mice displayed a decrease in levels of GSK-3β serine 9 phosphorylation and histone H3 acetylation in the striatum and cerebral cortex around the onset of behavioral deficits, indicating a hyperactivity of GSK-3β and HDACs. Using multiple well-validated behavioral tests, we found that co-treatment with lithium and VPA more effectively alleviated spontaneous locomotor deficits and depressive-like behaviors in both models of HD mice. Furthermore, compared with monotherapy with either drug alone, co-treatment more successfully improved motor skill learning and coordination in N171-82Q mice, and suppressed anxiety-like behaviors in YAC128 mice. This combined treatment consistently inhibited GSK-3β and HDACs, and caused a sustained elevation in striatal as well as cortical brain-derived neurotrophic factor and heat shock protein 70. Importantly, co-treatment markedly prolonged median survival of N171-82Q mice from 31.6 to 41.6 weeks. Given that there is presently no proven treatment for HD, our results suggest that combined treatment with lithium and VPA, two mood stabilizers with a long history of safe use in humans, may have important therapeutic potential for HD patients. PMID:21796107

A mechanistic approach to explore novel HDAC1 inhibitor using pharmacophore modeling, 3D- QSAR analysis, molecular docking, density functional and molecular dynamics simulation study.

PubMed

Choubey, Sanjay K; Jeyaraman, Jeyakanthan

2016-11-01

Deregulated epigenetic activity of Histone deacetylase 1 (HDAC1) in tumor development and carcinogenesis pronounces it as promising therapeutic target for cancer treatment. HDAC1 has recently captured the attention of researchers owing to its decisive role in multiple types of cancer. In the present study a multistep framework combining ligand based 3D-QSAR, molecular docking and Molecular Dynamics (MD) simulation studies were performed to explore potential compound with good HDAC1 binding affinity. Four different pharmacophore hypotheses Hypo1 (AADR), Hypo2 (AAAH), Hypo3 (AAAR) and Hypo4 (ADDR) were obtained. The hypothesis Hypo1 (AADR) with two hydrogen bond acceptors (A), one hydrogen bond donor (D) and one aromatics ring (R) was selected to build 3D-QSAR model on the basis of statistical parameter. The pharmacophore hypothesis produced a statistically significant QSAR model, with co-efficient of correlation r 2 =0.82 and cross validation correlation co-efficient q 2 =0.70. External validation result displays high predictive power with r 2 (o) value of 0.88 and r 2 (m) value of 0.58 to carry out further in silico studies. Virtual screening result shows ZINC70450932 as the most promising lead where HDAC1 interacts with residues Asp99, His178, Tyr204, Phe205 and Leu271 forming seven hydrogen bonds. A high docking score (-11.17kcal/mol) and lower docking energy -37.84kcal/mol) displays the binding efficiency of the ligand. Binding free energy calculation was done using MM/GBSA to access affinity of ligands towards protein. Density Functional Theory was employed to explore electronic features of the ligands describing intramolcular charge transfer reaction. Molecular dynamics simulation studies at 50ns display metal ion (Zn)-ligand interaction which is vital to inhibit the enzymatic activity of the protein. Copyright © 2016 Elsevier Inc. All rights reserved.

Histone Deacetylase 3 Prepares Brown Adipose Tissue For Acute Thermogenic Challenge

PubMed Central

Emmett, Matthew J.; Lim, Hee-Woong; Jager, Jennifer; Richter, Hannah J.; Adlanmerini, Marine; Peed, Lindsey C.; Briggs, Erika R.; Steger, David J.; Ma, Tao; Sims, Carrie A.; Baur, Joseph A.; Pei, Liming; Won, Kyoung-Jae; Seale, Patrick; Gerhart-Hines, Zachary; Lazar, Mitchell A.

2017-01-01

Brown adipose tissue (BAT) is a thermogenic organ that dissipates chemical energy as heat to protect animals against hypothermia and to counteract metabolic disease1. However, the transcriptional mechanisms that determine BAT thermogenic capacity prior to environmental cold are unknown. Here we show that Histone Deacetylase 3 (HDAC3) is required to activate BAT enhancers to ensure thermogenic aptitude. Mice with BAT-specific genetic ablation of HDAC3 become severely hypothermic and succumb to acute cold exposure. UCP1 is nearly absent in BAT lacking HDAC3 and there is also marked down-regulation of mitochondrial oxidative phosphorylation (OXPHOS) genes resulting in diminished mitochondrial respiration. Remarkably, although HDAC3 acts canonically as a transcriptional corepressor2, it functions as a coactivator of Estrogen-Related Receptor α (ERRα) in BAT. HDAC3 coactivation of ERRα is mediated by deacetylation of PGC-1α and is required for the transcription of Ucp1, Pgc-1α and OXPHOS genes. Importantly, HDAC3 promotes the basal transcription of these genes independent of adrenergic stimulation. Thus, HDAC3 uniquely primes Ucp1 and the thermogenic transcriptional program to maintain a critical capacity for thermogenesis in BAT that can be rapidly engaged upon exposure to dangerously cold temperature. PMID:28614293

Regulation of Histone Acetyltransferase TIP60 Function by Histone Deacetylase 3

PubMed Central

Yi, Jingjie; Huang, Xiangyang; Yang, Yuxia; Zhu, Wei-Guo; Gu, Wei; Luo, Jianyuan

2014-01-01

The key member of the MOZ (monocyticleukaemia zinc finger protein), Ybf2/Sas3, Sas2, and TIP60 acetyltransferases family, Tat-interactive protein, 60 kD (TIP60), tightly modulates a wide array of cellular processes, including chromatin remodeling, gene transcription, apoptosis, DNA repair, and cell cycle arrest. The function of TIP60 can be regulated by SIRT1 through deacetylation. Here we found that TIP60 can also be functionally regulated by HDAC3. We identified six lysine residues as its autoacetylation sites. Mutagenesis of these lysines to arginines completely abolishes the autoacetylation of TIP60. Overexpression of HDAC3 increases TIP60 ubiquitination levels. However, unlike SIRT1, HDAC3 increased the half-life of TIP60. Further study found that HDAC3 colocalized with TIP60 both in the nucleus and the cytoplasm, which could be the reason why HDAC3 can stabilize TIP60. The deacetylation of TIP60 by both SIRT1 and HDAC3 reduces apoptosis induced by DNA damage. Knockdown of HDAC3 in cells increased TIP60 acetylation levels and increased apoptosis after DNA damage. Together, our findings provide a better understanding of TIP60 regulation mechanisms, which is a significant basis for further studies of its cellular functions. PMID:25301942

Mule determines the apoptotic response to HDAC inhibitors by targeted ubiquitination and destruction of HDAC2

PubMed Central

Zhang, Jing; Kan, Shu; Huang, Brian; Hao, Zhenyue; Mak, Tak W.; Zhong, Qing

2011-01-01

Histone deacetylases (HDACs) are major epigenetic modulators involved in a broad spectrum of human diseases including cancers. Administration of HDAC inhibitors (HDACis) leads to growth inhibition, differentiation, and apoptosis of cancer cells. Understanding the regulatory mechanism of HDACs is imperative to harness the therapeutic potentials of HDACis. Here we show that HDACi- and DNA damage-induced apoptosis are severely compromised in mouse embryonic fibroblasts lacking a HECT domain ubiquitin ligase, Mule (Mcl-1 ubiquitin ligase E3). Mule specifically targets HDAC2 for ubiquitination and degradation. Accumulation of HDAC2 in Mule-deficient cells leads to compromised p53 acetylation as well as crippled p53 transcriptional activation, accumulation, and apoptotic response upon DNA damage and Nutlin-3 treatments. These defects in Mule-null cells can be partially reversed by HDACis and fully rescued by lowering the elevated HDAC2 in Mule-null cells to the normal levels as in wild-type cells. Taken together, our results reveal a critical regulatory mechanism of HDAC2 by Mule and suggest this pathway determines the cellular response to HDACis and DNA damage. PMID:22016339

Histone Deacetylase 6 Is a FoxO Transcription Factor-dependent Effector in Skeletal Muscle Atrophy*

PubMed Central

Ratti, Francesca; Ramond, Francis; Moncollin, Vincent; Simonet, Thomas; Milan, Giulia; Méjat, Alexandre; Thomas, Jean-Luc; Streichenberger, Nathalie; Gilquin, Benoit; Matthias, Patrick; Khochbin, Saadi; Sandri, Marco; Schaeffer, Laurent

2015-01-01

Skeletal muscle atrophy is a severe condition of muscle mass loss. Muscle atrophy is caused by a down-regulation of protein synthesis and by an increase of protein breakdown due to the ubiquitin-proteasome system and autophagy activation. Up-regulation of specific genes, such as the muscle-specific E3 ubiquitin ligase MAFbx, by FoxO transcription factors is essential to initiate muscle protein ubiquitination and degradation during atrophy. HDAC6 is a particular HDAC, which is functionally related to the ubiquitin proteasome system via its ubiquitin binding domain. We show that HDAC6 is up-regulated during muscle atrophy. HDAC6 activation is dependent on the transcription factor FoxO3a, and the inactivation of HDAC6 in mice protects against muscle wasting. HDAC6 is able to interact with MAFbx, a key ubiquitin ligase involved in muscle atrophy. Our findings demonstrate the implication of HDAC6 in skeletal muscle wasting and identify HDAC6 as a new downstream target of FoxO3a in stress response. This work provides new insights in skeletal muscle atrophy development and opens interesting perspectives on HDAC6 as a valuable marker of muscle atrophy and a potential target for pharmacological treatments. PMID:25516595

Concerted functions of HDAC1 and microRNA-574-5p repress alternatively spliced ceramide synthase 1 expression in human cancer cells

PubMed Central

Meyers-Needham, Marisa; Ponnusamy, Suriyan; Gencer, Salih; Jiang, Wenhui; Thomas, Raquela J; Senkal, Can E; Ogretmen, Besim

2012-01-01

Histone deacetylases (HDACs) and microRNAs (miRs) have pro-survival roles, but the mechanism behind this is unclear. Repression of ceramide synthase 1 (CerS1), altering C18-ceramide generation, was linked to drug resistance and metastasis. Here we report that the CerS1 promoter was repressed by HDAC1-dependent inhibition of Sp1 recruitment to two specific GC-boxes spanning the −177 and −139 region. Moreover, an alternatively spliced variant CerS1 mRNA (CerS1-2) was detected mainly in cancer cells or primary tumour tissues compared to controls, which was targeted by miR-574-5p for degradation. A specific 3′UTR-targeting site, localized within the retained intron between exons 6 and 7, was identified, and its mutation, or miR-574-5p knockdown prevented the degradation of CerS1-2 mRNA. Interference with HDAC1 and miR-574-5p reconstituted CerS1-2 expression and C18-ceramide generation in multiple human cancer cell lines, which subsequently inhibited proliferation and anchorage-independent growth. Accordingly, knockdown of CerS1 partially protected cancer cells from MS-275/miR-574-5p siRNA-mediated growth inhibition. Thus, these data suggest that the HDAC1/miR-574-5p axis might provide a novel therapeutic target to reconstitute tumour suppressor CerS1/ceramide signalling. PMID:22180294

Differential protein acetylation induced by novel histone deacetylase inhibitors.

PubMed

Glaser, K B; Li, J; Pease, L J; Staver, M J; Marcotte, P A; Guo, J; Frey, R R; Garland, R B; Heyman, H R; Wada, C K; Vasudevan, A; Michaelides, M R; Davidsen, S K; Curtin, M L

2004-12-17

Histone deacetylase (HDAC) inhibitors induce the hyperacetylation of nucleosomal histones in carcinoma cells resulting in the expression of repressed genes that cause growth arrest, terminal differentiation, and/or apoptosis. In vitro selectivity of several novel hydroxamate HDAC inhibitors including succinimide macrocyclic hydroxamates and the non-hydroxamate alpha-ketoamide inhibitors was investigated using isolated enzyme preparations and cellular assays. In vitro selectivity for the HDAC isozymes (HDAC1/2, 3, 4/3, and 6) was not observed for these HDAC inhibitors or the reference HDAC inhibitors, MS-275 and SAHA. In T24 and HCT116 cells these compounds caused the accumulation of acetylated histones H3 and H4; however, the succinimide macrocyclic hydroxamates and the alpha-ketoamides did not cause the accumulation of acetylated alpha-tubulin. These data suggest "selectivity" can be observed at the cellular level with HDAC inhibitors and that the nature of the zinc-chelating moiety is an important determinant of activity against tubulin deacetylase.

Design and synthesis of novel HDAC8 inhibitory 2,5-disubstituted-1,3,4-oxadiazoles containing glycine and alanine hybrids with anti cancer activity.

PubMed

Pidugu, Vijaya Rao; Yarla, Nagendra Sastry; Pedada, Srinivasa Rao; Kalle, Arunasree M; Satya, A Krishna

2016-11-01

Oxadiazole is a heterocyclic compound containing an oxygen atom and two nitrogen atoms in a five-membered ring. Of the four oxadiazoles known, 1,3,4-oxadiazole has become an important structural motif for the development of new drugs and the compounds containing 1,3,4-oxadiazole cores have a broad spectrum of biological activity. Herein, we describe the design, synthesis and biological evaluation of a series of novel 2,5-disubstituted 1,3,4-oxadiazoles (10a-10j) as class I histone deacetylase (HDAC) inhibitors. The compounds were designed and evaluated for HDAC8 selectivity using in silico docking software (Glide) and the top 10 compounds with high dock score and obeying Lipinski's rule were synthesized organically. Further the biological HDAC inhibitory and selectivity assays and anti-proliferative assays were carried out. In in silico and in vitro studies, all compounds (10a-10j) showed significant HDAC inhibition and exhibited HDAC8 selectivity. Among all tested compounds, 10b showed substantial HDAC8 inhibitory activity and better anticancer activity which is comparable to the positive control, a FDA approved drug, vorinostat (SAHA). Structural activity relation is discussed with various substitutions in the benzene ring connected on 1,3,4-oxadizole and glycine/alanine. The study warranted further investigations to develop HDAC8-selective inhibitory molecule as a drug for neoplastic diseases. Novel 1,3,4-oxadizole substituted with glycine/alanine showed HDAC8 inhibition. Copyright © 2016 Elsevier Ltd. All rights reserved.

Zinc chelation with hydroxamate in histone deacetylases modulated by water access to the linker binding channel.

PubMed

Wu, Ruibo; Lu, Zhenyu; Cao, Zexing; Zhang, Yingkai

2011-04-27

It is of significant biological interest and medical importance to develop class- and isoform-selective histone deacetylase (HDAC) modulators. The impact of the linker component on HDAC inhibition specificity has been revealed but is not understood. Using Born-Oppenheimer ab initio QM/MM MD simulations, a state-of-the-art approach to simulating metallo-enzymes, we have found that the hydroxamic acid remains to be protonated upon its binding to HDAC8, and thus disproved the mechanistic hypothesis that the distinct zinc-hydroxamate chelation modes between two HDAC subclasses come from different protonation states of the hydroxamic acid. Instead, our simulations suggest a novel mechanism in which the chelation mode of hydroxamate with the zinc ion in HDACs is modulated by water access to the linker binding channel. This new insight into the interplay between the linker binding and the zinc chelation emphasizes its importance and gives guidance regarding linker design for the development of new class-IIa-specific HDAC inhibitors.

Natural indoles, indole-3-carbinol and 3,3′-diindolymethane, inhibit T cell activation by staphylococcal enterotoxin B through epigenetic regulation involving HDAC expression

DOE Office of Scientific and Technical Information (OSTI.GOV)

Busbee, Philip B.; Nagarkatti, Mitzi; Nagarkatti, Prakash S., E-mail: prakash@mailbox.sc.edu

2014-01-01

Staphylococcal enterotoxin B (SEB) is a potent exotoxin produced by the Staphylococcus aureus. This toxin is classified as a superantigen because of its ability to directly bind with MHC-II class molecules followed by activation of a large proportion of T cells bearing specific Vβ-T cell receptors. Commonly associated with classic food poisoning, SEB has also been shown to induce toxic shock syndrome, and is also considered to be a potential biological warfare agent because it is easily aerosolized. In the present study, we assessed the ability of indole-3-carbinol (I3C) and one of its byproducts, 3,3′-diindolylmethane (DIM), found in cruciferous vegetables,more » to counteract the effects of SEB-induced activation of T cells in mice. Both I3C and DIM were found to decrease the activation, proliferation, and cytokine production by SEB-activated Vβ8{sup +} T cells in vitro and in vivo. Interestingly, inhibitors of histone deacetylase class I (HDAC-I), but not class II (HDAC-II), showed significant decrease in SEB-induced T cell activation and cytokine production, thereby suggesting that epigenetic modulation plays a critical role in the regulation of SEB-induced inflammation. In addition, I3C and DIM caused a decrease in HDAC-I but not HDAC-II in SEB-activated T cells, thereby suggesting that I3C and DIM may inhibit SEB-mediated T cell activation by acting as HDAC-I inhibitors. These studies not only suggest for the first time that plant-derived indoles are potent suppressors of SEB-induced T cell activation and cytokine storm but also that they may mediate these effects by acting as HDAC inhibitors. - Highlights: • I3C and DIM reduce SEB-induced T cell activation and inflammatory cytokines. • Inhibiting class I HDACs reduces T cell activation and inflammatory cytokines. • Inhibiting class II HDACs increases T cell activation and inflammatory cytokines. • I3C and DIM selectively reduce mRNA expression of class I HDACs. • Novel use and mechanism to counteract SEB with I3C and DIM.« less

Curcumin modulates the effect of histone modification on the expression of chemokines by type II alveolar epithelial cells in a rat COPD model.

PubMed

Gan, Lixing; Li, Chengye; Wang, Jian; Guo, Xuejun

2016-01-01

Studies have suggested that histone modification has a positive impact on various aspects associated with the progression of COPD. Histone deacetylase 2 (HDAC2) suppresses proinflammatory gene expression through deacetylation of core histones. To investigate the effect of histone modification on the expression of chemokines in type II alveolar epithelial cells (AEC II) in a rat COPD model and regulation of HDAC2 expression by curcumin in comparison with corticosteroid. The rat COPD model was established by cigarette smoke exposure and confirmed by histology and pathophysioloy. AEC II were isolated and cultured in vitro from the COPD models and control animals. The cells were treated with curcumin, corticosteroid, or trichostatin A, and messenger RNA (mRNA) expression of interleukin-8 (IL-8), monocyte chemoattractant protein-1 (MCP-1), and macrophage inflammatory protein-2α (MIP-2α) was assessed by quantitative real-time polymerase chain reaction (RT-PCR). The expression of HDAC2 was measured by Western blot. Chromatin immunoprecipitation was used to detect H3/H4 acetylation and H3K9 methylation in the promoter region of three kinds of chemokine genes (IL-8, MCP-1, and MIP-2α). Compared to the control group, the mRNAs of MCP-1, IL-8, and MIP-2α were upregulated 4.48-fold, 3.14-fold, and 2.83-fold, respectively, in the AEC II from COPD model. The protein expression of HDAC2 in the AEC II from COPD model was significantly lower than from the control group ( P <0.05). The decreased expression of HDAC2 was negatively correlated with the increased expression of IL-8, MCP-1, and MIP-2α mRNAs (all P <0.05). The level of H3/H4 acetylation was higher but H3K9 methylation in the promoter region of chemokine genes was lower in the cells from COPD model than from the control group (all P <0.05). Curcumin downregulated the expression of MCP-1, IL-8, and MIP-2α, and the expression was further enhanced in the presence of corticosteroid. Moreover, curcumin restored HDAC2 expression, decreased the levels of H3/H4 acetylation, and increased H3K9 methylation in the promoter region of chemokine in the presence or absence of dexamethasone (all P <0.05). Curcumin may suppress chemokines and restore corticosteroid resistance in COPD through modulating HDAC2 expression and its effect on histone modification.

Histone deacetylase 4 promotes ubiquitin-dependent proteasomal degradation of Sp3 in SH-SY5Y cells treated with di(2-ethylhexyl)phthalate (DEHP), determining neuronal death

DOE Office of Scientific and Technical Information (OSTI.GOV)

Guida, Natascia; Laudati, Giusy; Galgani, Mario

Phthalates, phthalic acid esters, are widely used as plasticizers to produce polymeric materials in industrial production of plastics and daily consumable products. Animal studies have shown that di(2-ethylhexyl)phthalate (DEHP) may cause toxic effects in the rat brain. In the present study, chronic exposure to DEHP (0.1–100 μM) caused dose-dependent cell death via the activation of caspase-3 in neuroblastoma cells. Intriguingly, this harmful effect was prevented by the pan-histone deacetylase (HDAC) inhibitor trichostatin A, by the class II HDAC inhibitor MC-1568, but not by the class I HDAC inhibitor MS-275. Furthermore, DEHP reduced specificity protein 3 (Sp3) gene expression, but notmore » Sp3 mRNA, after 24 and 48 h exposures. However, Sp3 protein reduction was prevented by pre-treatment with MC-1568, suggesting the involvement of class II HDACs in causing this effect. Then, we investigated the possible relationship between DEHP-induced neuronal death and the post-translational mechanisms responsible for the down-regulation of Sp3. Interestingly, DEHP-induced Sp3 reduction was associated to its deacetylation and polyubiquitination. Co-immunoprecipitation studies showed that Sp3 physically interacted with HDAC4 after DEHP exposure, while HDAC4 inhibition by antisense oligodeoxynucleotide reverted the DEHP-induced degradation of Sp3. Notably, Sp3 overexpression was able to counteract the detrimental effect induced by DEHP. Taken together, these results suggest that DEHP exerts its toxic effect by inducing deacetylation of Sp3 via HDAC4, and afterwards, Sp3-polyubiquitination. - Highlights: • Di(2-ethylhexyl)phthalate (DEHP) is cytotoxic to SH-SY5Y cells and cortical neurons. • DEHP-induced cytotoxicity is mediated by apoptosis. • DEHP-induced apoptotic cell death is inhibited by class II HDAC MC-1568. • DEHP neurotoxicity is caused by HDAC4-mediated Sp3 degradation by ubiquitin.« less

An HDAC-dependent epigenetic mechanism that enhances the efficacy of the antidepressant drug fluoxetine

PubMed Central

Schmauss, C.

2015-01-01

Depression is a prevalent and debilitating psychiatric illnesses. However, currently prescribed antidepressant drugs are only efficacious in a limited group of patients. Studies on Balb/c mice suggested that histone deacetylase (HDAC) inhibition may enhance the efficacy of the widely-prescribed antidepressant drug fluoxetine. This study shows that reducing HDAC activity in fluoxetine-treated Balb/c mice leads to robust antidepressant and anxiolytic effects. While reducing the activity of class I HDACs 1 and 3 led to antidepressant effects, additional class II HDAC inhibition was necessary to exert anxiolytic effects. In fluoxetine-treated mice, HDAC inhibitors increased enrichment of acetylated histone H4 protein and RNA polymerase II at promotor 3 of the brain-derived neurotrophic factor (Bdnf) gene and increased Bdnf transcription from this promotor. Reducing Bdnf-stimulated tropomyosin kinase B receptor activation in fluoxetine-treated mice with low HDAC activity abolished the behavioral effects of fluoxetine, suggesting that the HDAC-triggered epigenetic stimulation of Bdnf expression is critical for therapeutic efficacy. PMID:25639887

Orphan nuclear receptor TLX recruits histone deacetylases to repress transcription and regulate neural stem cell proliferation.

PubMed

Sun, Guoqiang; Yu, Ruth T; Evans, Ronald M; Shi, Yanhong

2007-09-25

TLX is a transcription factor that is essential for neural stem cell proliferation and self-renewal. However, the molecular mechanism of TLX-mediated neural stem cell proliferation and self-renewal is largely unknown. We show here that TLX recruits histone deacetylases (HDACs) to its downstream target genes to repress their transcription, which in turn regulates neural stem cell proliferation. TLX interacts with HDAC3 and HDAC5 in neural stem cells. The HDAC5-interaction domain was mapped to TLX residues 359-385, which contains a conserved nuclear receptor-coregulator interaction motif IXXLL. Both HDAC3 and HDAC5 have been shown to be recruited to the promoters of TLX target genes along with TLX in neural stem cells. Recruitment of HDACs led to transcriptional repression of TLX target genes, the cyclin-dependent kinase inhibitor, p21(CIP1/WAF1)(p21), and the tumor suppressor gene, pten. Either inhibition of HDAC activity or knockdown of HDAC expression led to marked induction of p21 and pten gene expression and dramatically reduced neural stem cell proliferation, suggesting that the TLX-interacting HDACs play an important role in neural stem cell proliferation. Moreover, expression of a TLX peptide containing the minimal HDAC5 interaction domain disrupted the TLX-HDAC5 interaction. Disruption of this interaction led to significant induction of p21 and pten gene expression and to dramatic inhibition of neural stem cell proliferation. Taken together, these findings demonstrate a mechanism for neural stem cell proliferation through transcriptional repression of p21 and pten gene expression by TLX-HDAC interactions.

A cyclodextrin-capped histone deacetylase inhibitor.

PubMed

Amin, Jahangir; Puglisi, Antonino; Clarke, James; Milton, John; Wang, Minghua; Paranal, Ronald M; Bradner, James E; Spencer, John

2013-06-01

We have synthesized a β-cyclodextrin (βCD)-capped histone deacetylase (HDAC) inhibitor 3 containing an alkyl linker and a zinc-binding hydroxamic acid motif. Biological evaluation (HDAC inhibition studies) of 3 enabled us to establish the effect of replacing an aryl cap (in SAHA (vorinostat,)) 1 by a large saccharidic scaffold "cap". HDAC inhibition was observed for 3, to a lesser extent than SAHA, and rationalized by molecular docking into the active site of HDAC8. However, compound 3 displayed no cellular activity. Copyright © 2013 Elsevier Ltd. All rights reserved.

Altered interaction of HDAC5 with GATA-1 during MEL cell differentiation.

PubMed

Watamoto, Kouichi; Towatari, Masayuki; Ozawa, Yukiyasu; Miyata, Yasuhiko; Okamoto, Mitsunori; Abe, Akihiro; Naoe, Tomoki; Saito, Hidehiko

2003-12-11

The transcription factor GATA-1 plays a significant role in erythroid differentiation and association with CBP stimulates its activity by acetylation. It is possible that histone deacetylases (HDACs) repress the activity of GATA-1. In the present study, we investigated whether class I and class II HDACs interact with GATA-1 to regulate its function and indeed, GATA-1 is directly associated with HDAC3, HDAC4 and HDAC5. The expression profiling and our previous observation that GATA-2 interacts with members of the HDAC family prompted us to investigate further the biological relevance of the interaction between GATA-1 and HDAC5. Coexpression of HDAC5 suppressed the transcriptional potential of GATA-1. Our results demonstrated that GATA-1 and HDAC5 colocalized to the nucleus of murine erythroleukemia (MEL) cells. Furthermore, a portion of HDAC5 moved to the cytoplasm concomitant with MEL cell erythroid differentiation, which was induced by treatment with N,N'-hexamethylenebisacetamide. These observations support the suggestion that control of the HDAC5 nucleocytoplasmic distribution might be associated with MEL cell differentiation, possibly through regulated GATA-1 transactivation.

Design and synthesis of novel and highly-active pan-histone deacetylase (pan-HDAC) inhibitors.

PubMed

Tashima, Toshihiko; Murata, Hiroaki; Kodama, Hidehiko

2014-07-15

Histone deacetylase (HDAC) inhibitions are known to elicit anticancer effects. We designed and synthesized several HDAC inhibitors. Among these compounds, compound 40 exhibited a more than 10-fold stronger inhibitory activity compared with that of suberoylanilide hydroxamic acid (SAHA) against each human HDAC isozyme in vitro (IC50 values of 40: HDAC1, 0.0038μM; HDAC2, 0.0082μM; HDAC3, 0.015μM; HDAC8, 0.0060μM; HDAC4, 0.058μM; HDAC9, 0.0052μM; HDAC6, 0.058μM). The dose of the administered HDAC inhibitors that contain hydroxamic acid as the zinc-binding group may be reduced by 40. Because the carbostyril subunit is a time-tested structural component of drugs and biologically active compounds, 40 most likely exhibits good absorption, distribution, metabolism, excretion, and toxicity (ADMET). Thus, compound 40 is expected to be a promising therapeutic agent or chemical tool for the investigation of life process. Copyright © 2014 Elsevier Ltd. All rights reserved.

Quantitative structure-activity relationship analysis and virtual screening studies for identifying HDAC2 inhibitors from known HDAC bioactive chemical libraries.

PubMed

Pham-The, H; Casañola-Martin, G; Diéguez-Santana, K; Nguyen-Hai, N; Ngoc, N T; Vu-Duc, L; Le-Thi-Thu, H

2017-03-01

Histone deacetylases (HDAC) are emerging as promising targets in cancer, neuronal diseases and immune disorders. Computational modelling approaches have been widely applied for the virtual screening and rational design of novel HDAC inhibitors. In this study, different machine learning (ML) techniques were applied for the development of models that accurately discriminate HDAC2 inhibitors form non-inhibitors. The obtained models showed encouraging results, with the global accuracy in the external set ranging from 0.83 to 0.90. Various aspects related to the comparison of modelling techniques, applicability domain and descriptor interpretations were discussed. Finally, consensus predictions of these models were used for screening HDAC2 inhibitors from four chemical libraries whose bioactivities against HDAC1, HDAC3, HDAC6 and HDAC8 have been known. According to the results of virtual screening assays, structures of some hits with pair-isoform-selective activity (between HDAC2 and other HDACs) were revealed. This study illustrates the power of ML-based QSAR approaches for the screening and discovery of potent, isoform-selective HDACIs.

Histone Deacetylase 3 Suppresses Erk Phosphorylation and Matrix Metalloproteinase (Mmp)-13 Activity in Chondrocytes

PubMed Central

Carpio, Lomeli R.; Bradley, Elizabeth W.; Westendorf, Jennifer J.

2017-01-01

Histone deacetylase inhibitors are emerging therapies for many diseases including cancers and neurological disorders; however, these drugs are teratogens to the developing skeleton. Hdac3 is essential for proper endochondral ossification as its deletion in chondrocytes increases cytokine signaling and the expression of matrix remodeling enzymes. Here we explored the mechanism by which Hdac3 controls Mmp13 expression in chondrocytes. In Hdac3-depleted chondrocytes, Erk1/2 as well as its downstream substrate, Runx2, were hyperphosphorylated as a result of decreased expression and activity of the Erk1/2 specific phosphatase, Dusp6. Erk1/2 kinase inhibitors and Dusp6 adenoviruses reduced Mmp13 expression and partially rescued matrix production in Hdac3-deficient chondrocytes. Postnatal chondrocyte-specific deletion of Hdac3 with an inducible Col2a1-Cre caused premature production of pErk1/2 and Mmp13 in the growth plate. Thus, Hdac3 controls the temporal and spatial expression of tissue-remodeling genes in chondrocytes to ensure proper endochondral ossification during development. PMID:27662443

The co-existence of transcriptional activator and transcriptional repressor MEF2 complexes influences tumor aggressiveness

PubMed Central

Di Giorgio, Eros; Franforte, Elisa; Cefalù, Sebastiano; Rossi, Sabrina; Dei Tos, Angelo Paolo; Polano, Maurizio; Maestro, Roberta; Paluvai, Harikrishnareddy

2017-01-01

The contribution of MEF2 TFs to the tumorigenic process is still mysterious. Here we clarify that MEF2 can support both pro-oncogenic or tumor suppressive activities depending on the interaction with co-activators or co-repressors partners. Through these interactions MEF2 supervise histone modifications associated with gene activation/repression, such as H3K4 methylation and H3K27 acetylation. Critical switches for the generation of a MEF2 repressive environment are class IIa HDACs. In leiomyosarcomas (LMS), this two-faced trait of MEF2 is relevant for tumor aggressiveness. Class IIa HDACs are overexpressed in 22% of LMS, where high levels of MEF2, HDAC4 and HDAC9 inversely correlate with overall survival. The knock out of HDAC9 suppresses the transformed phenotype of LMS cells, by restoring the transcriptional proficiency of some MEF2-target loci. HDAC9 coordinates also the demethylation of H3K4me3 at the promoters of MEF2-target genes. Moreover, we show that class IIa HDACs do not bind all the regulative elements bound by MEF2. Hence, in a cell MEF2-target genes actively transcribed and strongly repressed can coexist. However, these repressed MEF2-targets are poised in terms of chromatin signature. Overall our results candidate class IIa HDACs and HDAC9 in particular, as druggable targets for a therapeutic intervention in LMS. PMID:28419090

Natural products as zinc-dependent histone deacetylase inhibitors.

PubMed

Tan, Shuai; Liu, Zhao-Peng

2015-03-01

Zinc-dependent histone deacetylases (HDACs), a family of hydrolases that remove acetyl groups from lysine residues, play an important role in the regulation of multiple processes, from gene expression to protein activity. The dysregulation of HDACs is associated with many diseases including cancer, neurological disorders, cellular metabolism disorders, and inflammation. Molecules that act as HDAC inhibitors (HDACi) exhibit a variety of related bioactivities. In particular, HDACi have been applied clinically for the treatment of cancers. Inhibition through competitive binding of the catalytic domain of these enzymes has been achieved by a diverse array of small-molecule chemotypes, including a number of natural products. This review provides a systematic introduction of natural HDACi, with an emphasis on their enzyme inhibitory potency, selectivity, and biological activities, highlighting their various binding modes with HDACs. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Antidepressants and mood stabilizers effects on histone deacetylase expression in C57BL/6 mice: Brain region specific changes.

PubMed

Ookubo, Masanori; Kanai, Hirohiko; Aoki, Harusuke; Yamada, Naoto

2013-09-01

To determine whether treatment with various antidepressants or mood stabilizers leads to region-specific changes, we investigated the effects of their subchronic (14 days of intraperitoneal injection) administration on the tissue concentration of monoamines, dopamine, serotonin, and norepinephrine, and the protein expression of acetylated histone H3 (AcH3) and histone deacetylases (HDACs) in the mouse striatum (ST), nucleus accumbens (Acb), hippocampus (Hip), cingulate cortex (Cg), and amygdala (Amy). Subchronic administration with the antidepressants (S)-citalopram oxalate (ECM), duloxetine hydrochloride (DLX), and mirtazapine (MIR) commonly induced significant increases in dopamine and serotonin levels in the ST and Cg. By contrast, no common profiles for dopamine, serotonin, or norepinephrine were identified in the Acb, Hip, or Amy. Treatment with sodium valproate (VPA), lithium chloride (Li), lamotrigine (LTG), levetiracetam (LTM), olanzapine (OLZ), clozapine (CLZ), clomipramine (CLM), ECM, and DLX induced significant increases in AcH3 expression in the Acb, while treatment with CLM, ECM, DLX, MIR, carbamazepine (CBZ), LTG, LTM, OLZ, or CLZ induced significant increases in HDAC2 and HDAC3 in the ST. CLM, MIR, VPA, CBZ, LTG, LTM, OLZ, or CLZ induced significant increases in HDAC3 in the Cg, and ECM, DLX, MIR, VPA, CBZ, LTG, LTM, or OLZ resulted in significant increases in HDAC5 in the Amy. Collectively, the changes of monoamine content were restricted for mood stabilizer effects, but increased expression of HDAC2, HDAC3, or HDAC5 in the ST, Cg, or Amy was often found, supporting the possibility that antidepressant-like effects involve epigenetic modifications associated with changes in HDAC expression. Copyright © 2013 Elsevier Ltd. All rights reserved.

Mule determines the apoptotic response to HDAC inhibitors by targeted ubiquitination and destruction of HDAC2.

PubMed

Zhang, Jing; Kan, Shu; Huang, Brian; Hao, Zhenyue; Mak, Tak W; Zhong, Qing

2011-12-15

Histone deacetylases (HDACs) are major epigenetic modulators involved in a broad spectrum of human diseases including cancers. Administration of HDAC inhibitors (HDACis) leads to growth inhibition, differentiation, and apoptosis of cancer cells. Understanding the regulatory mechanism of HDACs is imperative to harness the therapeutic potentials of HDACis. Here we show that HDACi- and DNA damage-induced apoptosis are severely compromised in mouse embryonic fibroblasts lacking a HECT domain ubiquitin ligase, Mule (Mcl-1 ubiquitin ligase E3). Mule specifically targets HDAC2 for ubiquitination and degradation. Accumulation of HDAC2 in Mule-deficient cells leads to compromised p53 acetylation as well as crippled p53 transcriptional activation, accumulation, and apoptotic response upon DNA damage and Nutlin-3 treatments. These defects in Mule-null cells can be partially reversed by HDACis and fully rescued by lowering the elevated HDAC2 in Mule-null cells to the normal levels as in wild-type cells. Taken together, our results reveal a critical regulatory mechanism of HDAC2 by Mule and suggest this pathway determines the cellular response to HDACis and DNA damage. © 2011 by Cold Spring Harbor Laboratory Press

Discovery of a new class of histone deacetylase inhibitors with a novel zinc binding group.

PubMed

Li, Youxuan; Woster, Patrick M

2015-04-01

Small molecules featuring a hydroxamic acid or a benzamide zinc binding group (ZBG) are the most thoroughly studied histone deacetylase (HDAC) inhibitors. However, concerns about the pharmacokinetic liabilities of the hydroxamic acid moiety and potential metabolic toxicity of the aniline portion of benzamide HDAC inhibitors have stimulated research efforts aimed at discovering alternative ZBGs. Here we report the 2-(oxazol-2-yl)phenol moiety as a novel ZBG that can be used to produce compounds that are potent HDAC inhibitors. A series of analogues with this novel ZBG have been synthesized, and these analogues exhibit selective inhibition against HDAC1 as well as the class IIb HDACs (HDAC6 and HDAC10). Compound 10 possesses an IC 50 value of 7.5 μM in the MV-4-11 leukemia cell line, and induces a comparable amount of acetylated histone 3 lysine 9 (H3K9) and p21Waf1/CIP1 as 0.5 μM of SAHA. Modeling of compound 10 in the active site of HDAC2 demonstrates that the 2-(oxazol-2-yl)phenol moiety has a zinc-binding pattern similar to benzamide HDAC inhibitors.

Orphan nuclear receptor TLX recruits histone deacetylases to repress transcription and regulate neural stem cell proliferation

PubMed Central

Sun, GuoQiang; Yu, Ruth T.; Evans, Ronald M.; Shi, Yanhong

2007-01-01

TLX is a transcription factor that is essential for neural stem cell proliferation and self-renewal. However, the molecular mechanism of TLX-mediated neural stem cell proliferation and self-renewal is largely unknown. We show here that TLX recruits histone deacetylases (HDACs) to its downstream target genes to repress their transcription, which in turn regulates neural stem cell proliferation. TLX interacts with HDAC3 and HDAC5 in neural stem cells. The HDAC5-interaction domain was mapped to TLX residues 359–385, which contains a conserved nuclear receptor–coregulator interaction motif IXXLL. Both HDAC3 and HDAC5 have been shown to be recruited to the promoters of TLX target genes along with TLX in neural stem cells. Recruitment of HDACs led to transcriptional repression of TLX target genes, the cyclin-dependent kinase inhibitor, p21CIP1/WAF1(p21), and the tumor suppressor gene, pten. Either inhibition of HDAC activity or knockdown of HDAC expression led to marked induction of p21 and pten gene expression and dramatically reduced neural stem cell proliferation, suggesting that the TLX-interacting HDACs play an important role in neural stem cell proliferation. Moreover, expression of a TLX peptide containing the minimal HDAC5 interaction domain disrupted the TLX–HDAC5 interaction. Disruption of this interaction led to significant induction of p21 and pten gene expression and to dramatic inhibition of neural stem cell proliferation. Taken together, these findings demonstrate a mechanism for neural stem cell proliferation through transcriptional repression of p21 and pten gene expression by TLX–HDAC interactions. PMID:17873065

The HDAC6/8/10 inhibitor TH34 induces DNA damage-mediated cell death in human high-grade neuroblastoma cell lines.

PubMed

Kolbinger, Fiona R; Koeneke, Emily; Ridinger, Johannes; Heimburg, Tino; Müller, Michael; Bayer, Theresa; Sippl, Wolfgang; Jung, Manfred; Gunkel, Nikolas; Miller, Aubry K; Westermann, Frank; Witt, Olaf; Oehme, Ina

2018-06-09

High histone deacetylase (HDAC) 8 and HDAC10 expression levels have been identified as predictors of exceptionally poor outcomes in neuroblastoma, the most common extracranial solid tumor in childhood. HDAC8 inhibition synergizes with retinoic acid treatment to induce neuroblast maturation in vitro and to inhibit neuroblastoma xenograft growth in vivo. HDAC10 inhibition increases intracellular accumulation of chemotherapeutics through interference with lysosomal homeostasis, ultimately leading to cell death in cultured neuroblastoma cells. So far, no HDAC inhibitor covering HDAC8 and HDAC10 at micromolar concentrations without inhibiting HDACs 1, 2 and 3 has been described. Here, we introduce TH34 (3-(N-benzylamino)-4-methylbenzhydroxamic acid), a novel HDAC6/8/10 inhibitor for neuroblastoma therapy. TH34 is well-tolerated by non-transformed human skin fibroblasts at concentrations up to 25 µM and modestly impairs colony growth in medulloblastoma cell lines, but specifically induces caspase-dependent programmed cell death in a concentration-dependent manner in several human neuroblastoma cell lines. In addition to the induction of DNA double-strand breaks, HDAC6/8/10 inhibition also leads to mitotic aberrations and cell-cycle arrest. Neuroblastoma cells display elevated levels of neuronal differentiation markers, mirrored by formation of neurite-like outgrowths under maintained TH34 treatment. Eventually, after long-term treatment, all neuroblastoma cells undergo cell death. The combination of TH34 with plasma-achievable concentrations of retinoic acid, a drug applied in neuroblastoma therapy, synergistically inhibits colony growth (combination index (CI) < 0.1 for 10 µM of each). In summary, our study supports using selective HDAC inhibitors as targeted antineoplastic agents and underlines the therapeutic potential of selective HDAC6/8/10 inhibition in high-grade neuroblastoma.

Naturally occurring benzoic acid derivatives retard cancer cell growth by inhibiting histone deacetylases (HDAC)

PubMed Central

Anantharaju, Preethi G.; Reddy, Bandi Deepa; Padukudru, Mahesh A.; Kumari Chitturi, CH. M.; Vimalambike, Manjunath G.

2017-01-01

ABSTRACT Histone deacetylases (HDACs), which modulate the expression of genes, are potential therapeutic targets in several cancers. Targeted inhibition of HDAC prevents the expression of oncogenes thereby help in the treatment of cancers. Hence, several pharmaceutical companies developed inhibitors of HDAC and tested them in preclinical models and in clinical trials. SAHA (suberanilohydroxamic acid) is one such HDAC inhibitor developed for treating breast and colorectal carcinomas. However, due to poor efficacy in clinical trials the utility of SAHA for treating cancers was discouraged. Similarly another HDAC inhibitor Trichostatin-A (TSA) also showed promising results in clinical trials but exhibited severe adverse effects, which dampened the interest of using this molecule for cancer treatment. Therefore, search for developing a potent HDAC inhibitor with minimal side effects still continues. Hence, in this study we have screened benzoic acid and benzoic acid derivatives with hydroxylic (-OH) groups and methoxy (-OCH3) groups for their efficacy to bind to the TSA binding site of HDAC using molecular docking studies. Molecules that showed much stronger affinity (than TSA) to HDAC were tested for inhibiting HDAC expressing cultured cancer cells. DHBA but not Dimethoxy Benzoic Acid (DMBA) inhibited HDAC activity, leading to cancer cell growth inhibition through the induction of ROS and cellular apoptosis mediated by Caspase-3. In addition, DHBA arrested cells in G2/M phase of the cell cycle and elevated the levels of sub-G0-G1 cell population. In summary, results of this study report that DHBA could be a strong HDAC inhibitor and inhibit cancer cell growth more effectively. PMID:28506198

Histone deacetylase inhibitors with a primary amide zinc binding group display antitumor activity in xenograft model.

PubMed

Attenni, Barbara; Ontoria, Jesus M; Cruz, Jonathan C; Rowley, Michael; Schultz-Fademrecht, Carsten; Steinkühler, Christian; Jones, Philip

2009-06-01

Histone deacetylase (HDAC) inhibition causes hyperacetylation of histones leading to differentiation, growth arrest and apoptosis of malignant cells, representing a new strategy in cancer therapy. Many of the known HDAC inhibitors (HDACi) that are in clinical trials possess a hydroxamic acid, that is a strong Zn(2+) binding group, thereby inhibiting some of the class I and class II isoforms. Herein we describe the identification of a selective class I HDAC inhibitor bearing a primary carboxamide moiety as zinc binding group. This HDACi displays good antiproliferative activity against multiple cancer cell lines, and demonstrates efficacy in a xenograft model comparable to vorinostat.

Overexpressed HDAC8 in cervical cancer cells shows functional redundancy of tubulin deacetylation with HDAC6.

PubMed

Vanaja, G R; Ramulu, Hemalatha Golaconda; Kalle, Arunasree M

2018-05-02

Histone deacetylases (HDACs) are involved in epigenetic gene regulation via deacetylation of acetylated lysine residues of both histone and non-histone proteins. Among the 18 HDACs identified in humans, HDAC8, a class I HDAC, is best understood structurally and enzymatically. However, its precise subcellular location, function in normal cellular physiology, its protein partners and substrates still remain elusive. The subcellular localization of HDAC8 was studied using immunofluorescence and confocal imaging. The binding parterns were identified employing immunoprecipitation (IP) followed by MALDI-TOF analysis and confirmed using in-silico protein-protein interaction studies, HPLC-based in vitro deacetylation assay, intrinsic fluorescence spectrophotometric analysis, Circular dichroism (CD) and Surface Plasmon Resonance (SPR). Functional characterization of the binding was carried out using immunoblot and knockdown by siRNA. Using one way ANOVA statistical significance (n = 3) was determined. Here, we show that HDAC8 and its phosphorylated form (pHDAC8) localized predominantly in the cytoplasm in cancerous, HeLa, and non-cancerous (normal), HEK293T, cells, although nucleolar localization was observed in HeLa cells. The study identified Alpha tubulin as a novel interacting partner of HDAC8. Further, the results indicated binding and deacetylation of tubulin at ac-lys40 by HDAC8. Knockdown of HDAC8 by siRNA, inhibition of HDAC8 and/or HDAC6 by PCI-34051 and tubastatin respectively, cell-migration, cell morphology and cell cycle analysis clearly explained HDAC8 as tubulin deacetylase in HeLa cells and HDAC6 in HEK 293 T cells. HDAC8 shows functional redundancy with HDAC6 when overexpressed in cervical cancer cells, HeLa, and deacetylaes ac-lys40 of alpha tubulin leading to cervical cancer proliferation and progression.

Histone deacetylase 8 regulates cortactin deacetylation and contraction in smooth muscle tissues

PubMed Central

Li, Jia; Chen, Shu; Cleary, Rachel A.; Wang, Ruping; Gannon, Olivia J.; Seto, Edward

2014-01-01

Histone deacetylases (HDACs) are a family of enzymes that mediate nucleosomal histone deacetylation and gene expression. Some members of the HDAC family have also been implicated in nonhistone protein deacetylation, which modulates cell-cycle control, differentiation, and cell migration. However, the role of HDACs in smooth muscle contraction is largely unknown. Here, HDAC8 was localized both in the cytoplasm and the nucleus of mouse and human smooth muscle cells. Knockdown of HDAC8 by lentivirus-encoding HDAC8 shRNA inhibited force development in response to acetylcholine. Treatment of smooth muscle tissues with HDAC8 inhibitor XXIV (OSU-HDAC-44) induced relaxation of precontracted smooth muscle tissues. In addition, cortactin is an actin-regulatory protein that undergoes deacetylation during migration of NIH 3T3 cells. In this study, acetylcholine stimulation induced cortactin deacetylation in mouse and human smooth muscle tissues, as evidenced by immunoblot analysis using antibody against acetylated lysine. Knockdown of HDAC8 by RNAi or treatment with the inhibitor attenuated cortactin deacetylation and actin polymerization without affecting myosin activation. Furthermore, expression of a charge-neutralizing cortactin mutant inhibited contraction and actin dynamics during contractile activation. These results suggest a novel mechanism for the regulation of smooth muscle contraction. In response to contractile stimulation, HDAC8 may mediate cortactin deacetylation, which subsequently promotes actin filament polymerization and smooth muscle contraction. PMID:24920679

HDAC inhibitors: modulating leukocyte differentiation, survival, proliferation and inflammation.

PubMed

Sweet, Matthew J; Shakespear, Melanie R; Kamal, Nabilah A; Fairlie, David P

2012-01-01

Therapeutic effects of histone deacetylase (HDAC) inhibitors in cancer models were first linked to their ability to cause growth arrest and apoptosis of tumor cells. It is now clear that these agents also have pleiotropic effects on angiogenesis and the immune system, and some of these properties are likely to contribute to their anti-cancer activities. It is also emerging that inhibitors of specific HDACs affect the differentiation, survival and/or proliferation of distinct immune cell populations. This is true for innate immune cells such as macrophages, as well as cells of the acquired immune system, for example, T-regulatory cells. These effects may contribute to therapeutic profiles in some autoimmune and chronic inflammatory disease models. Here, we review our current understanding of how classical HDACs (HDACs 1-11) and their inhibitors impact on differentiation, survival and proliferation of distinct leukocyte populations, as well as the likely relevance of these effects to autoimmune and inflammatory disease processes. The ability of HDAC inhibitors to modulate leukocyte survival may have implications for the rationale of developing selective inhibitors as anti-inflammatory drugs.

Liganded Peroxisome Proliferator-Activated Receptors (PPARs) Preserve Nuclear Histone Deacetylase 5 Levels in Endothelin-Treated Sprague-Dawley Rat Cardiac Myocytes

PubMed Central

Zhang, Haining; Shao, Zongjun; Alibin, Caroline P.; Acosta, Crystal; Anderson, Hope D.

2014-01-01

Ligand activation of peroxisome proliferator-activated receptors (PPARs) prevents cardiac myocyte hypertrophy, and we previously reported that diacylglycerol kinase zeta (DGKζ) is critically involved. DGKζ is an intracellular lipid kinase that catalyzes phosphorylation of diacylglycerol; by attenuating DAG signaling, DGKζ suppresses protein kinase C (PKC) and G-protein signaling. Here, we investigated how PPAR-DGKζ signaling blocks activation of the hypertrophic gene program. We focused on export of histone deacetylase 5 (HDAC5) from the nucleus, a key event during hypertrophy, since crosstalk occurs between PPARs and other members of the HDAC family. Using cardiac myocytes isolated from Sprague-Dawley rats, we determined that liganded PPARs disrupt endothelin-1 (ET1)-induced nuclear export of HDAC5 in a manner that is dependent on DGKζ. When DGKζ-mediated PKC inhibition was circumvented using a constitutively-active PKCε mutant, PPARs failed to block ET1-induced nuclear retention of HDAC5. Liganded PPARs also prevented (i) activation of protein kinase D (the downstream effector of PKC), (ii) HDAC5 phosphorylation at 14-3-3 protein chaperone binding sites (serines 259 and 498), and (iii) physical interaction between HDAC5 and 14-3-3, all of which are consistent with blockade of nucleo-cytoplasmic shuttling of HDAC5. Finally, the ability of PPARs to prevent neutralization of HDAC5 activity was associated with transcriptional repression of hypertrophic genes. This occurred by first, reduced MEF2 transcriptional activity and second, augmented deacetylation of histone H3 associated with hypertrophic genes expressing brain natriuretic peptide, β-myosin heavy chain, skeletal muscle α-actin, and cardiac muscle α-actin. Our findings identify spatial regulation of HDAC5 as a target for liganded PPARs, and to our knowledge, are the first to describe a mechanistic role for nuclear DGKζ in cardiac myocytes. In conclusion, these results implicate modulation of HDAC5 as a mechanism by which liganded PPARs suppress the hypertrophic gene program. PMID:25514029

Decreased histone deacetylase 2 impairs Nrf2 activation by oxidative stress

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mercado, Nicolas; Thimmulappa, Rajesh; Thomas, Catherine M.R.

2011-03-11

Research highlights: {yields} Nrf2 anti-oxidant function is impaired when HDAC activity is inhibited. {yields} HDAC inhibition decreases Nrf2 protein stability. {yields} HDAC2 is involved in reduced Nrf2 stability and both correlate in COPD samples. {yields} HDAC inhibition increases Nrf2 acetylation. -- Abstract: Nuclear factor erythroid 2-related factor 2 (Nrf2) plays a crucial role in cellular defence against oxidative stress by inducing the expression of multiple anti-oxidant genes. However, where high levels of oxidative stress are observed, such as chronic obstructive pulmonary disease (COPD), Nrf2 activity is reduced, although the molecular mechanism for this defect is uncertain. Here, we show thatmore » down-regulation of histone deacetylase (HDAC) 2 causes Nrf2 instability, resulting in reduced anti-oxidant gene expression and increase sensitivity to oxidative stress. Although Nrf2 protein was clearly stabilized after hydrogen peroxide (H{sub 2}O{sub 2}) stimulation in a bronchial epithelial cell line (BEAS2B), Nrf2 stability was decreased and Nrf2 acetylation increased in the presence of an HDAC inhibitor, trichostatin A (TSA). TSA also reduced Nrf2-regulated heme-oxygenase-1 (HO-1) expression in these cells, and this was confirmed in acute cigarette-smoke exposed mice in vivo. HDAC2 knock-down by RNA interference resulted in reduced H{sub 2}O{sub 2}-induced Nrf2 protein stability and activity in BEAS2B cells, whereas HDAC1 knockdown had no effect. Furthermore, monocyte-derived macrophages obtained from healthy volunteers (non-smokers and smokers) and COPD patients showed a significant correlation between HDAC2 expression and Nrf2 expression (r = 0.92, p < 0.0001). Thus, reduced HDAC2 activity in COPD may account for increased Nrf2 acetylation, reduced Nrf2 stability and impaired anti oxidant defences.« less

Novel histone deacetylase inhibitor N25 exerts anti-tumor effects and induces autophagy in human glioma cells by inhibiting HDAC3

PubMed Central

Sun, Xin-Yuan; Qu, Yue; Ni, An-Ran; Wang, Gui-Xiang; Huang, Wei-Bin; Chen, Zhong-Ping; Lv, Zhu-Fen; Zhang, Song; Lindsay, Holly; Zhao, Sibo; Li, Xiao-Nan; Feng, Bing-Hong

2017-01-01

N25, a novel histone deacetylase inhibitor, was created through structural modification of suberoylanilide hydroxamic acid. To evaluate the anti-tumor activity of N25 and clarify its molecular mechanism of inducing autophagy in glioma cells, we investigated its in vitro anti-proliferative effect and in vivo anticancer effect. Moreover, we detected whether N25 induces autophagy in glioma cells by transmission electron microscope and analyzed the protein expression level of HDAC3, Tip60, LC3 in glioma samples by western blot. We additionally analyzed the protein expression level of HDAC3, Tip60, ULK1 (Atg1), and Beclin-1 (Atg6) after treatment with N25 in glioma cells. Our results showed that the anti-tumor activity of N25 in glioma cells is slightly stronger than SAHA both in vitro and in vivo. We found that N25 induced autophagy, and HDAC3 was significantly elevated and Tip60 and LC3 significantly decreased in glioma samples compared with normal brain tissues. Nevertheless, N25 inhibited HDAC3 and up-regulated the protein expression of Tip60, ULK1 (Atg1), and Beclin-1 (Atg6) after treatment of glioma cells with N25. In conclusion, these data suggest that N25 has striking anti-tumor activity in part due to inhibition of HDAC3. Additionally, N25 may induce autophagy through inhibiting HDAC3. PMID:29088860

[Effect of hydroquinone on the histone deacetylase in human bone marrow mononuclear cells].

PubMed

Hong, L L; Yu, K; Yan, Q X; Xu, X; Shi, Y F; Ge, H P

2016-03-20

To observe the activity of histone deacetylase and the mRNA expression level of HDAC1 and HDAC2 in human bone marrow mononuclear cells, which induced by hydroquinone and exposed to hydroquinone plus Trichostatin as a histone deacetylase inhibitor for 10 hours respectively. Collect the bone marrow mononuclear cells suspension,divided into control group,HQ group (3 h, 6 h, 12 h, 24 h) , HQ+TSA 10 h group and HQ 10 h group. Extract the nuclear proteins and RNA, test the activity of histone deacetylase with the colorimetric HDAC assay kit and detect the mRNA expression level of HDAC1 and HDAC2 by real-time Polymerase Chain Reaction (PCR). The HDAC activity of HQ3 h group, HQ6 h group and HQ12 h group were 1.31 times, 1.53 times and 1.148 times than that of control group respectively. And the difference was statistically significant (P<0.05). Except the HQ24 h group (P>0.05) , the HDAC1 mRNA expression of HQ3 h group, HQ6 h group and HQ12 h group were 1.173 times, 1.901 times and 2.348 times than that of control group respectively. And the difference was statistically significant (P<0.05). The HDAC2 mRNA expression of HQ6 h group and HQ12 h group were 1.426 times and 1.766 times than that of the control group respectively. And the difference was statistically significant (P<0.05). No significant difference was observed between HQ3 h group, HQ24 h group and control group (P>0.05). The cells were treated by hydroquinone plus TSA for 10 hours. The HDAC activity of HQ+TSA 10h group was reduced by 25.6% than that of HQ 10 h group (P<0.05) and rised 13.0% compared to the control group (P<0.05). And the difference was statistically significant between groups (P<0.05) .The cells were treated by hydroquinone plus TSA for 10 hours. The HDAC1 mRNA expression of the HQ+TSA 10h group is reduced by 26.9% than that of HQ10h group. The HDAC2 mRNA expression is reduced by 19.3% compared to the HQ 10h group.And the difference was statistically significant between groups (P<0.05). The HDAC1 and HDAC2 mRNA expression is obviously higher than the control group, the difference was statistically significant (P<0.05). Treatment of hydroquinone, the histone deacetylase activity and the mRNA expression of HDAC1 and HDAC2 were increased in a certain time range. The histone deacetylase inhibitor (TSA) can reduce the histone deacetylase activity and the mRNA expression level of HDAC1 and HDAC2 in the bone marrow mononuclear cell induce by hydroquinone.It can be confirmed that hematopoietic damage induced by the benzene metabolites is related to the histone acetylation modification level.

Histone deacetylase and Cullin3-REN(KCTD11) ubiquitin ligase interplay regulates Hedgehog signalling through Gli acetylation.

PubMed

Canettieri, Gianluca; Di Marcotullio, Lucia; Greco, Azzura; Coni, Sonia; Antonucci, Laura; Infante, Paola; Pietrosanti, Laura; De Smaele, Enrico; Ferretti, Elisabetta; Miele, Evelina; Pelloni, Marianna; De Simone, Giuseppina; Pedone, Emilia Maria; Gallinari, Paola; Giorgi, Alessandra; Steinkühler, Christian; Vitagliano, Luigi; Pedone, Carlo; Schinin, M Eugenià; Screpanti, Isabella; Gulino, Alberto

2010-02-01

Hedgehog signalling is crucial for development and is deregulated in several tumours, including medulloblastoma. Regulation of the transcriptional activity of Gli (glioma-associated oncogene) proteins, effectors of the Hedgehog pathway, is poorly understood. We show here that Gli1 and Gli2 are acetylated proteins and that their HDAC-mediated deacetylation promotes transcriptional activation and sustains a positive autoregulatory loop through Hedgehog-induced upregulation of HDAC1. This mechanism is turned off by HDAC1 degradation through an E3 ubiquitin ligase complex formed by Cullin3 and REN, a Gli antagonist lost in human medulloblastoma. Whereas high HDAC1 and low REN expression in neural progenitors and medulloblastomas correlates with active Hedgehog signalling, loss of HDAC activity suppresses Hedgehog-dependent growth of neural progenitors and tumour cells. Consistent with this, abrogation of Gli1 acetylation enhances cellular proliferation and transformation. These data identify an integrated HDAC- and ubiquitin-mediated circuitry, where acetylation of Gli proteins functions as an unexpected key transcriptional checkpoint of Hedgehog signalling.

A Thoroughly Validated Virtual Screening Strategy for Discovery of Novel HDAC3 Inhibitors.

PubMed

Hu, Huabin; Xia, Jie; Wang, Dongmei; Wang, Xiang Simon; Wu, Song

2017-01-18

Histone deacetylase 3 (HDAC3) has been recently identified as a potential target for the treatment of cancer and other diseases, such as chronic inflammation, neurodegenerative diseases, and diabetes. Virtual screening (VS) is currently a routine technique for hit identification, but its success depends on rational development of VS strategies. To facilitate this process, we applied our previously released benchmarking dataset, i.e., MUBD-HDAC3 to the evaluation of structure-based VS (SBVS) and ligand-based VS (LBVS) combinatorial approaches. We have identified FRED (Chemgauss4) docking against a structural model of HDAC3, i.e., SAHA-3 generated by a computationally inexpensive "flexible docking", as the best SBVS approach and a common feature pharmacophore model, i.e., Hypo1 generated by Catalyst/HipHop as the optimal model for LBVS. We then developed a pipeline that was composed of Hypo1, FRED (Chemgauss4), and SAHA-3 sequentially, and demonstrated that it was superior to other combinations in terms of ligand enrichment. In summary, we present the first highly-validated, rationally-designed VS strategy specific to HDAC3 inhibitor discovery. The constructed pipeline is publicly accessible for the scientific community to identify novel HDAC3 inhibitors in a time-efficient and cost-effective way.

A Thoroughly Validated Virtual Screening Strategy for Discovery of Novel HDAC3 Inhibitors

PubMed Central

Hu, Huabin; Xia, Jie; Wang, Dongmei; Wang, Xiang Simon; Wu, Song

2017-01-01

Histone deacetylase 3 (HDAC3) has been recently identified as a potential target for the treatment of cancer and other diseases, such as chronic inflammation, neurodegenerative diseases, and diabetes. Virtual screening (VS) is currently a routine technique for hit identification, but its success depends on rational development of VS strategies. To facilitate this process, we applied our previously released benchmarking dataset, i.e., MUBD-HDAC3 to the evaluation of structure-based VS (SBVS) and ligand-based VS (LBVS) combinatorial approaches. We have identified FRED (Chemgauss4) docking against a structural model of HDAC3, i.e., SAHA-3 generated by a computationally inexpensive “flexible docking”, as the best SBVS approach and a common feature pharmacophore model, i.e., Hypo1 generated by Catalyst/HipHop as the optimal model for LBVS. We then developed a pipeline that was composed of Hypo1, FRED (Chemgauss4), and SAHA-3 sequentially, and demonstrated that it was superior to other combinations in terms of ligand enrichment. In summary, we present the first highly-validated, rationally-designed VS strategy specific to HDAC3 inhibitor discovery. The constructed pipeline is publicly accessible for the scientific community to identify novel HDAC3 inhibitors in a time-efficient and cost-effective way. PMID:28106794

Histone Deacetylase 6 (HDAC6) Is an Essential Modifier of Glucocorticoid-Induced Hepatic Gluconeogenesis

PubMed Central

Winkler, Robin; Benz, Verena; Clemenz, Markus; Bloch, Mandy; Foryst-Ludwig, Anna; Wardat, Sami; Witte, Nicole; Trappiel, Manuela; Namsolleck, Pawel; Mai, Knut; Spranger, Joachim; Matthias, Gabriele; Roloff, Tim; Truee, Oliver; Kappert, Kai; Schupp, Michael; Matthias, Patrick; Kintscher, Ulrich

2012-01-01

In the current study, we investigated the importance of histone deacetylase (HDAC)6 for glucocorticoid receptor–mediated effects on glucose metabolism and its potential as a therapeutic target for the prevention of glucocorticoid-induced diabetes. Dexamethasone-induced hepatic glucose output and glucocorticoid receptor translocation were analyzed in wild-type (wt) and HDAC6-deficient (HDAC6KO) mice. The effect of the specific HDAC6 inhibitor tubacin was analyzed in vitro. wt and HDAC6KO mice were subjected to 3 weeks’ dexamethasone treatment before analysis of glucose and insulin tolerance. HDAC6KO mice showed impaired dexamethasone-induced hepatic glucocorticoid receptor translocation. Accordingly, dexamethasone-induced expression of a large number of hepatic genes was significantly attenuated in mice lacking HDAC6 and by tubacin in vitro. Glucose output of primary hepatocytes from HDAC6KO mice was diminished. A significant improvement of dexamethasone-induced whole-body glucose intolerance as well as insulin resistance in HDAC6KO mice compared with wt littermates was observed. This study demonstrates that HDAC6 is an essential regulator of hepatic glucocorticoid-stimulated gluconeogenesis and impairment of whole-body glucose metabolism through modification of glucocorticoid receptor nuclear translocation. Selective pharmacological inhibition of HDAC6 may provide a future therapeutic option against the prodiabetogenic actions of glucocorticoids. PMID:22210316

Class IIa histone deacetylases are hormone-activated regulators of FOXO and mammalian glucose homeostasis.

PubMed

Mihaylova, Maria M; Vasquez, Debbie S; Ravnskjaer, Kim; Denechaud, Pierre-Damien; Yu, Ruth T; Alvarez, Jacqueline G; Downes, Michael; Evans, Ronald M; Montminy, Marc; Shaw, Reuben J

2011-05-13

Class IIa histone deacetylases (HDACs) are signal-dependent modulators of transcription with established roles in muscle differentiation and neuronal survival. We show here that in liver, class IIa HDACs (HDAC4, 5, and 7) are phosphorylated and excluded from the nucleus by AMPK family kinases. In response to the fasting hormone glucagon, class IIa HDACs are rapidly dephosphorylated and translocated to the nucleus where they associate with the promoters of gluconeogenic enzymes such as G6Pase. In turn, HDAC4/5 recruit HDAC3, which results in the acute transcriptional induction of these genes via deacetylation and activation of FOXO family transcription factors. Loss of class IIa HDACs in murine liver results in inhibition of FOXO target genes and lowers blood glucose, resulting in increased glycogen storage. Finally, suppression of class IIa HDACs in mouse models of type 2 diabetes ameliorates hyperglycemia, suggesting that inhibitors of class I/II HDACs may be potential therapeutics for metabolic syndrome. Copyright © 2011 Elsevier Inc. All rights reserved.

Histone Deacetylase 3 (HDAC3)-dependent Reversible Lysine Acetylation of Cardiac Myosin Heavy Chain Isoforms Modulates Their Enzymatic and Motor Activity*

PubMed Central

Samant, Sadhana A.; Pillai, Vinodkumar B.; Sundaresan, Nagalingam R.; Shroff, Sanjeev G.; Gupta, Mahesh P.

2015-01-01

Reversible lysine acetylation is a widespread post-translational modification controlling the activity of proteins in different subcellular compartments. We previously demonstrated that a class II histone deacetylase (HDAC), HDAC4, and a histone acetyltransferase, p300/CREB-binding protein-associated factor, associate with cardiac sarcomeres and that a class I and II HDAC inhibitor, trichostatin A, enhances contractile activity of myofilaments. In this study we show that a class I HDAC, HDAC3, is also present at cardiac sarcomeres. By immunohistochemical and electron microscopic analyses, we found that HDAC3 was localized to A-band of sarcomeres and capable of deacetylating myosin heavy chain (MHC) isoforms. The motor domains of both cardiac α- and β-MHC isoforms were found to be reversibly acetylated. Biomechanical studies revealed that lysine acetylation significantly decreased the Km for the actin-activated ATPase activity of MHC isoforms. By in vitro motility assay, we found that lysine acetylation increased the actin-sliding velocity of α-myosin by 20% and β-myosin by 36% compared with their respective non-acetylated isoforms. Moreover, myosin acetylation was found to be sensitive to cardiac stress. During induction of hypertrophy, myosin isoform acetylation increased progressively with duration of stress stimuli independently of isoform shift, suggesting that lysine acetylation of myosin could be an early response of myofilaments to increase contractile performance of the heart. These studies provide the first evidence for localization of HDAC3 at myofilaments and uncover a novel mechanism modulating the motor activity of cardiac MHC isoforms. PMID:25911107

Uncoupling of Protein Aggregation and Neurodegeneration in a Mouse Amyotrophic Lateral Sclerosis Model.

PubMed

Lee, Joo-Yong; Kawaguchi, Yoshiharu; Li, Ming; Kapur, Meghan; Choi, Su Jin; Kim, Hak-June; Park, Song-Yi; Zhu, Haining; Yao, Tso-Pang

2015-01-01

Aberrant accumulation of protein aggregates is a pathological hallmark of many neurodegenerative diseases, including amyotrophic lateral sclerosis (ALS). Although a buildup of protein aggregates frequently leads to cell death, whether it is the key pathogenic factor in driving neurodegenerative disease remains controversial. HDAC6, a cytosolic ubiquitin-binding deacetylase, has emerged as an important regulator of ubiquitin-dependent quality control autophagy, a lysosome-dependent degradative system responsible for the disposal of misfolded protein aggregates and damaged organelles. Here, we show that in cell models HDAC6 plays a protective role against multiple disease-associated and aggregation-prone cytosolic proteins by facilitating their degradation. We further show that HDAC6 is required for efficient localization of lysosomes to protein aggregates, indicating that lysosome targeting to autophagic substrates is regulated. Supporting a critical role of HDAC6 in protein aggregate disposal in vivo, genetic ablation of HDAC6 in a transgenic SOD1G93A mouse, a model of ALS, leads to dramatic accumulation of ubiquitinated SOD1G93A protein aggregates. Surprisingly, despite a robust buildup of SOD1G93A aggregates, deletion of HDAC6 only moderately modified the motor phenotypes. These findings indicate that SOD1G93A aggregation is not the only determining factor to drive neurodegeneration in ALS, and that HDAC6 likely modulates neurodegeneration through additional mechanisms beyond protein aggregate clearance. © 2015 S. Karger AG, Basel.

HDAC3-selective inhibitor enhances extinction of cocaine-seeking behavior in a persistent manner.

PubMed

Malvaez, Melissa; McQuown, Susan C; Rogge, George A; Astarabadi, Mariam; Jacques, Vincent; Carreiro, Samantha; Rusche, James R; Wood, Marcelo A

2013-02-12

Nonspecific histone deacetylase (HDAC) inhibition has been shown to facilitate the extinction of drug-seeking behavior in a manner resistant to reinstatement. A key open question is which specific HDAC is involved in the extinction of drug-seeking behavior. Using the selective HDAC3 inhibitor RGFP966, we investigated the role of HDAC3 in extinction and found that systemic treatment with RGFP966 facilitates extinction in mice in a manner resistant to reinstatement. We also investigated whether the facilitated extinction is related to the enhancement of extinction consolidation during extinction learning or to negative effects on performance or reconsolidation. These are key distinctions with regard to any compound being used to modulate extinction, because a more rapid decrease in a defined behavior is interpreted as facilitated extinction. Using an innovative combination of behavioral paradigms, we found that a single treatment of RGFP966 enhances extinction of a previously established cocaine-conditioned place preference, while simultaneously enhancing long-term object-location memory within subjects. During extinction consolidation, HDAC3 inhibition promotes a distinct pattern of histone acetylation linked to gene expression within the infralimbic cortex, hippocampus, and nucleus accumbens. Thus, the facilitated extinction of drug-seeking cannot be explained by adverse effects on performance. These results demonstrate that HDAC3 inhibition enhances the memory processes involved in extinction of drug-seeking behavior.

Synthesis and Biological Evaluation of 1-(2-Aminophenyl)-3-arylurea Derivatives as Potential EphA2 and HDAC Dual Inhibitors.

PubMed

Zhu, Yong; Ran, Ting; Chen, Xin; Niu, Jiaqi; Zhao, Shuang; Lu, Tao; Tang, Weifang

2016-01-01

A series of 1-(2-aminophenyl)-3-arylurea novel derivatives were synthesized and evaluated against Ephrin type-A receptor 2 (EphA2) and histone deacetylases (HDACs) kinase. Most of the compounds exhibited inhibitory activity against EphA2 and HDAC. The antiproliferative activities were evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) (thiazolyl blue, tetrazolium blue) against the human cancer cell lines HCT116, K562 and MCF7. Compounds 5a and b showed the most potent inhibitory activity against EphA2 and HDAC. However, compound 5b exhibited higher potency against HCT116 (IC50=5.29 µM) and MCF7 (IC50=7.42 µM). 1-(2-Aminophenyl)-3-arylurea analogues may serve as new EphA2-HDAC dual inhibitors.

Associations between cruciferous vegetable intake and selected biomarkers among women scheduled for breast biopsies.

PubMed

Zhang, Zhenzhen; Atwell, Lauren L; Farris, Paige E; Ho, Emily; Shannon, Jackilen

2016-05-01

To examine the relationship between dietary cruciferous vegetable intake and selected tumour biomarkers for histone acetylation (H3K9ac, H3K18ac, HDAC3 and HDAC6), proliferation (Ki-67) and cell-cycle regulation (p21) from breast tissue. The study used baseline data of women recruited to participate in a clinical trial of sulforaphane supplement. Dietary cruciferous vegetable intake was collected through a validated Arizona Cruciferous Vegetable Intake Questionnaire. Breast tissue was obtained from biopsy samples. Spearman correlations were calculated between intake of specific cruciferous vegetables and biomarkers. Tissue biomarkers were log2-transformed to obtain approximate normality. Linear regression analyses were conducted to examine associations between cruciferous vegetable intake and biomarkers adjusting for age and use of non-steroidal anti-inflammatory drugs. False discovery rate (FDR) was used to account for multiple comparisons. Clinical trial baseline. Fifty-four women who had abnormal mammogram findings and were scheduled for breast biopsy. Mean intake of total cruciferous vegetables from all food sources was 81·7 (sd 57·3) g/d. Mean urinary total sulforaphane metabolites was 0·08 (sd 0·07) µm/mm creatinine. Total cruciferous vegetable intake was inversely associated with Ki-67 protein expression in breast ductal carcinoma in situ (DCIS) tissue (β=-0·004; se=0·001; FDR q value=0·03), but not in benign or invasive ductal carcinoma (IDC) tissue. No association was found for other biomarkers measured (HDAC3, HDAC6, H3K9, H3K18 and p21) in all tissues examined (benign, DCIS and IDC). The present study sought to provide additional evidence for the potential role of sulforaphane in histone acetylation and cell proliferation. Here, we report that total cruciferous vegetable intake is associated with decreased cell proliferation in breast DCIS tissue.

Plant-derived flavone Apigenin: The small-molecule with promising activity against therapeutically resistant prostate cancer.

PubMed

Ganai, Shabir Ahmad

2017-01-01

Prostate cancer is the second leading cause of cancer related deaths in men in the United States. Mounting evidences suggest that in the pathophysiology of prostate cancer epigenetic modifications play a considerable role. Histone deacetylases (HDACs) have strong crosstalk with prostate cancer progression as they regulate various genes meant for tumour suppression. HDACs are emerging as striking molecular targets for anticancer drugs and therapy as their aberrant expression has been implicated in several cancers. Histone deacetylase inhibitors (HDACi), the small molecules interfering HDACs are the propitious chemotherapeutic agents as they tune the altered acetylation homeostasis for attenuating disease signalling. More than 20 HDACi have entered into the clinical trials and 4 have crossed the journey by gaining FDA approval for treating distinct haematological malignancies including multiple myeloma. Despite the therapeutic benefits, the synthetic HDACi cause detrimental side effects like atrial fibrillation, raising concerns regarding their applicability. Taking these facts into consideration the current article focused on plant-derived HDAC inhibitor Apigenin and its marvelous role in prostate cancer therapy. Moreover, the article sheds light on Apigenin induced apoptosis in various prostate cancer models. The defined inhibitor provokes apoptotic signaling in these models by multiple mechanisms like restraining HDACs, declining the levels of antiapoptotic proteins. Importantly, Apigenin hampers NF-κB signalling and down-modulates its regulated gene products for bringing therapeutic effect. Furthermore, Apigenin shows synergistic effect in combinatorial therapy and induces apoptosis even in prostate cancer models resistant to conventional therapeutic regimens. Copyright © 2016 Elsevier Masson SAS. All rights reserved.

A homogeneous cellular histone deacetylase assay suitable for compound profiling and robotic screening.

PubMed

Ciossek, Thomas; Julius, Heiko; Wieland, Heike; Maier, Thomas; Beckers, Thomas

2008-01-01

Most cellular assays that quantify the efficacy of histone deacetylase (HDAC) inhibitors measure hyperacetylation of core histone proteins H3 and H4. Here we describe a new approach, directly measuring cellular HDAC enzymatic activity using the substrate Boc-K(Ac)-7-amino-4-methylcoumarin (AMC). After penetration into HeLa cervical carcinoma or K562 chronic myeloid leukemia cells, the deacetylated product Boc-K-AMC is formed which, after cell lysis, is cleaved by trypsin, finally releasing the fluorophor AMC. The cellular potency of suberoylanilide hydroxamic acid, LBH589, trichostatin A, and MS275 as well-known HDAC inhibitors was determined using this assay. IC(50) values derived from concentration-effect curves correlated well with EC(50) values derived from a cellomics array scan histone H3 hyperacetylation assay. The cellular HDAC activity assay was adapted to a homogeneous format, fully compatible with robotic screening. Concentration-effect curves generated on a Tecan Genesis Freedom workstation were highly reproducible with a signal-to-noise ratio of 5.7 and a Z' factor of 0.88, indicating a very robust assay. Finally, a HDAC-inhibitor focused library was profiled in a medium-throughput screening campaign. Inhibition of cellular HDAC activity correlated well with cytotoxicity and histone H3 hyperacetylation in HeLa cells and with inhibition of human recombinant HDAC1 in a biochemical assay. Thus, by using Boc-K(Ac)-AMC as a cell-permeable HDAC substrate, the activity of various protein lysine-specific deacetylases including HDAC1-containing complexes is measurable in intact cells in a simple and homogeneous manner.

Anti-Inflammatory Effects of Spirulina platensis Extract via the Modulation of Histone Deacetylases.

PubMed

Pham, Tho X; Park, Young-Ki; Lee, Ji-Young

2016-06-21

We previously demonstrated that the organic extract of Spirulina platensis (SPE), an edible blue-green alga, possesses potent anti-inflammatory effects. In this study, we investigated if the regulation of histone deacetylases (HDACs) play a role in the anti-inflammatory effect of SPE in macrophages. Treatment of macrophages with SPE rapidly and dose-dependently reduced HDAC2, 3, and 4 proteins which preceded decreases in their mRNA levels. Degradation of HDAC4 protein was attenuated in the presence of inhibitors of calpain proteases, lysosomal acidification, and Ca(2+)/calmodulin-dependent protein kinase II, respectively, but not a proteasome inhibitor. Acetylated histone H3 was increased in SPE-treated macrophages to a similar level as macrophages treated with a pan-HDAC inhibitor, with concomitant inhibition of inflammatory gene expression upon LPS stimulation. Knockdown of HDAC3 increased basal and LPS-induced pro-inflammatory gene expression, while HDAC4 knockdown increased basal expression of interleukin-1β (IL-1β), but attenuated LPS-induced inflammatory gene expression. Chromatin immunoprecipitation showed that SPE decreased p65 binding and H3K9/K14 acetylation at the Il-1β and tumor necrosis factor α (Tnfα) promoters. Our results suggest that SPE increased global histone H3 acetylation by facilitating HDAC protein degradation, but decreases histone H3K9/K14 acetylation and p65 binding at the promoters of Il-1β and Tnfα to exert its anti-inflammatory effect.

Chemical and genetic blockade of HDACs enhances osteogenic differentiation of human adipose tissue-derived stem cells by oppositely affecting osteogenic and adipogenic transcription factors

DOE Office of Scientific and Technical Information (OSTI.GOV)

Maroni, Paola; Brini, Anna Teresa; Dipartimento di Scienze Biomediche, Chirurgiche ed Odontoiatriche, Universita degli Studi di Milano, Milano

2012-11-16

Highlights: Black-Right-Pointing-Pointer Acetylation affected hASCs osteodifferentiation through Runx2-PPAR{gamma}. Black-Right-Pointing-Pointer HDACs knocking-down favoured the commitment effect of osteogenic medium. Black-Right-Pointing-Pointer HDACs silencing early activated Runx2 and ALP. Black-Right-Pointing-Pointer PPAR{gamma} reduction and calcium/collagen deposition occurred later. Black-Right-Pointing-Pointer Runx2/PPAR{gamma} target genes were modulated in line with HDACs role in osteo-commitment. -- Abstract: The human adipose-tissue derived stem/stromal cells (hASCs) are an interesting source for bone-tissue engineering applications. Our aim was to clarify in hASCs the role of acetylation in the control of Runt-related transcription factor 2 (Runx2) and Peroxisome proliferator activated receptor (PPAR) {gamma}. These key osteogenic and adipogenic transcription factors are oppositelymore » involved in osteo-differentiation. The hASCs, committed or not towards bone lineage with osteoinductive medium, were exposed to HDACs chemical blockade with Trichostatin A (TSA) or were genetically silenced for HDACs. Alkaline phosphatase (ALP) and collagen/calcium deposition, considered as early and late osteogenic markers, were evaluated concomitantly as index of osteo-differentiation. TSA pretreatment, useful experimental protocol to analyse pan-HDAC-chemical inhibition, and switch to osteogenic medium induced early-osteoblast maturation gene Runx2, while transiently decreased PPAR{gamma} and scarcely affected late-differentiation markers. Time-dependent effects were observed after knocking-down of HDAC1 and 3: Runx2 and ALP underwent early activation, followed by late-osteogenic markers increase and by PPAR{gamma}/ALP activity diminutions mostly after HDAC3 silencing. HDAC1 and 3 genetic blockade increased and decreased Runx2 and PPAR{gamma} target genes, respectively. Noteworthy, HDACs knocking-down favoured the commitment effect of osteogenic medium. Our results reveal a role for HDACs in orchestrating osteo-differentiation of hASCs at transcriptional level, and might provide new insights into the modulation of hASCs-based regenerative therapy.« less

HDAC and Ku70 axis- an effective target for apoptosis induction by a new 2-cyano-3-oxo-1,9-dien glycyrrhetinic acid analogue.

PubMed

Gong, Ping; Li, Kun; Li, Ying; Liu, Dan; Zhao, Linxiang; Jing, Yongkui

2018-05-24

Methyl 2-cyano-3,12-dioxo-18β-olean-1,9(11)-dien-30-oate (CDODO-Me, 10d) derived from glycyrrhetinic acid and methyl-2-cyano-3,12-dioxooleana-1,9-dien-28-oic acid (CDDO-Me) derived from oleanoic acid are potent apoptosis inducers developed to clinical trials. Both compounds have high affinity for reduced  glutathione (GSH), which needs to be overcome to improve their target selectivity. We generated a new 10d analogue methyl 2-cyano-3-oxo-18β-olean-1,9(11), 12-trien-30-oate (COOTO, 10e), which retains high apoptosis inducing ability, while displaying decreased affinity for GSH, and explored the acting targets. We found that it induces Noxa level, reduces c-Flip level and causes Bax/Bak activation. Silencing of either Noxa or Bak significantly attenuated apoptosis induction of 10e. We linked these events due to targeting HDAC3/HDAC6 and Ku70 axis. 10e treatment reduced the levels of HDAC3 and HDAC6 with increased DNA damage/repair marker gamma-H2AX (γ-H2AX) and acetylated Ku70. c-Flip dissociates from acetylated Ku70 undergoing degradation, while Bax dissociates from acetylated Ku70 undergoing activation. Silencing of either HDAC3 or HDAC6 enhanced 10e-induced apoptosis. We reveal a new action cascade of this category of compounds that involves targeting of HADC3/6 proteins and Ku70 acetylation.

Epigenetic regulation of vascular smooth muscle cell proliferation and neointima formation by histone deacetylase inhibition.

PubMed

Findeisen, Hannes M; Gizard, Florence; Zhao, Yue; Qing, Hua; Heywood, Elizabeth B; Jones, Karrie L; Cohn, Dianne; Bruemmer, Dennis

2011-04-01

Proliferation of smooth muscle cells (SMC) in response to vascular injury is central to neointimal vascular remodeling. There is accumulating evidence that histone acetylation constitutes a major epigenetic modification for the transcriptional control of proliferative gene expression; however, the physiological role of histone acetylation for proliferative vascular disease remains elusive. In the present study, we investigated the role of histone deacetylase (HDAC) inhibition in SMC proliferation and neointimal remodeling. We demonstrate that mitogens induce transcription of HDAC 1, 2, and 3 in SMC. Short interfering RNA-mediated knockdown of either HDAC 1, 2, or 3 and pharmacological inhibition of HDAC prevented mitogen-induced SMC proliferation. The mechanisms underlying this reduction of SMC proliferation by HDAC inhibition involve a growth arrest in the G(1) phase of the cell cycle that is due to an inhibition of retinoblastoma protein phosphorylation. HDAC inhibition resulted in a transcriptional and posttranscriptional regulation of the cyclin-dependent kinase inhibitors p21(Cip1) and p27(Kip). Furthermore, HDAC inhibition repressed mitogen-induced cyclin D1 mRNA expression and cyclin D1 promoter activity. As a result of this differential cell cycle-regulatory gene expression by HDAC inhibition, the retinoblastoma protein retains a transcriptional repression of its downstream target genes required for S phase entry. Finally, we provide evidence that these observations are applicable in vivo by demonstrating that HDAC inhibition decreased neointima formation and expression of cyclin D1 in a murine model of vascular injury. These findings identify HDAC as a critical component of a transcriptional cascade regulating SMC proliferation and suggest that HDAC might play a pivotal role in the development of proliferative vascular diseases, including atherosclerosis and in-stent restenosis.

Epigenetic Regulation of Vascular Smooth Muscle Cell Proliferation and Neointima Formation by Histone Deacetylase Inhibition

PubMed Central

Findeisen, Hannes M.; Gizard, Florence; Zhao, Yue; Qing, Hua; Heywood, Elizabeth B.; Jones, Karrie L.; Cohn, Dianne; Bruemmer, Dennis

2011-01-01

Objective Proliferation of smooth muscle cells (SMC) in response to vascular injury is central to neointimal vascular remodeling. There is accumulating evidence that histone acetylation constitutes a major epigenetic modification for the transcriptional control of proliferative gene expression; however, the physiological role of histone acetylation for proliferative vascular disease remains elusive. Methods and Results In the present study, we investigated the role of histone deacetylase (HDAC) inhibition in SMC proliferation and neointimal remodeling. We demonstrate that mitogens induce transcription of HDAC 1, 2 and 3 in SMC. siRNA-mediated knock-down of either HDAC 1, 2 or 3 and pharmacologic inhibition of HDAC prevented mitogen-induced SMC proliferation. The mechanisms underlying this reduction of SMC proliferation by HDAC inhibition involve a growth arrest in the G1-phase of the cell cycle due to an inhibition of retinoblastoma protein phosphorylation. HDAC inhibition resulted in a transcriptional and posttranscriptional regulation of the cyclin-dependent kinase inhibitors p21Cip1 and p27Kip. Furthermore, HDAC inhibition repressed mitogen-induced cyclin D1 mRNA expression and cyclin D1 promoter activity. As a result of this differential cell cycle-regulatory gene expression by HDAC inhibition, the retinoblastoma protein retains a transcriptional repression of its downstream target genes required for S phase entry. Finally, we provide evidence that these observations are applicable in vivo by demonstrating that HDAC inhibition decreased neointima formation and expression of cyclin D1 in a murine model of vascular injury. Conclusion These findings identify HDAC as a critical component of a transcriptional cascade regulating SMC proliferation and suggest that HDAC might play a pivotal role in the development of proliferative vascular diseases, including atherosclerosis and in-stent restenosis. PMID:21233448

Epigenetic suppression of potassium-chloride co-transporter 2 expression in inflammatory pain induced by complete Freund's adjuvant (CFA).

PubMed

Lin, C-R; Cheng, J-K; Wu, C-H; Chen, K-H; Liu, C-K

2017-02-01

Multiple mechanisms contribute to the stimulus-evoked pain hypersensitivity that may be experienced after peripheral inflammation. Persistent pathological stimuli in many pain conditions affect the expression of certain genes through epigenetic alternations. The main purpose of our study was to investigate the role of epigenetic modification on potassium-chloride co-transporter 2 (KCC2) gene expression in the persistence of inflammatory pain. Persistent inflammatory pain was induced through the injection of complete Freund's adjuvant (CFA) in the left hind paw of rats. Acetyl-histone H3 and H4 level was determined by chromatin immunoprecipitation in the spinal dorsal horn. Pain behaviour and inhibitory synaptic function of spinal cord were determined before and after CFA injection. KCC2 expression was determined by real time RT-PCR and Western blot. Intrathecal KCC2 siRNA (2 μg per 10 μL per rat) or HDAC inhibitor (10 μg per 10 μL per rat) was injected once daily for 3 days before CFA injection. Persistent inflammatory pain epigenetically suppressed KCC2 expression through histone deacetylase (HDAC)-mediated histone hypoacetylation, resulting in decreased inhibitory signalling efficacy. KCC2 knock-down caused by intrathecal administration of KCC2 siRNA in naïve rats reduced KCC2 expression in the spinal cord, leading to sensitized pain behaviours and impaired inhibitory synaptic transmission in their spinal cords. Moreover, intrathecal HDAC inhibitor injection in CFA rats increased KCC2 expression, partially restoring the spinal inhibitory synaptic transmission and relieving the sensitized pain behaviour. These findings suggest that the transcription of spinal KCC2 is regulated by histone acetylation epigenetically following CFA. Persistent pain suppresses KCC2 expression through HDAC-mediated histone hypoacetylation and consequently impairs the inhibitory function of inhibitory interneurons. Drugs such as HDAC inhibitors that suppress the influences of persistent pain on the expression of KCC2 may serve as a novel analgesic. © 2016 European Pain Federation - EFIC®.

Knockdown of HDAC1 expression suppresses invasion and induces apoptosis in glioma cells.

PubMed

Wang, Xiao-Qiang; Bai, Hong-Min; Li, Shi-Ting; Sun, Hui; Min, Ling-Zhao; Tao, Bang-Bao; Zhong, Jun; Li, Bin

2017-07-18

Glioma is the most common malignant tumor of the central nervous system, with a low survival rate of five years worldwide. Although high expression and prognostic value of histone deacetylase 1 (HDAC1) have been recently reported in various types of human tumors, the molecular mechanism underlying the biological function of HDAC1 in glioma is still unclear. We found that HDAC1 was elevated in glioma tissues and cell lines. HDAC1 expression was closely related with pathological grade and overall survival of patients with gliomas. Downregulation of HDAC1 inhibited cell proliferation, prevented invasion of glioma cell lines, and induced cell apoptosis. The expression of apoptosis and metastasis related molecules were detected by RT-PCR and Western blot, respectively, in U251 and T98G cells with HDAC1 knockdown. We found that HDAC1 knockdown upregulated expression of BIM, BAX, cleaved CASPASE3 and E-CADHERIN, and decreased expression of TWIST1, SNAIL and MMP9 in U251 and T98G cells with HDAC1 knockdown. In vivo data showed that knockdown of HDAC1 inhibited tumor growth in nude mice. In summary, HDAC1 may therefore be considered an unfavorable progression indicator for glioma patients, and may also serve as a potential therapeutic target.

Phosphatase inhibition leads to histone deacetylases 1 and 2 phosphorylation and disruption of corepressor interactions.

PubMed

Galasinski, Scott C; Resing, Katheryn A; Goodrich, James A; Ahn, Natalie G

2002-05-31

The regulation of histone deacetylases (HDACs) by phosphorylation was examined by elevating intracellular phosphorylation in cultured cells with the protein phosphatase inhibitor okadaic acid. After fractionation of extracts from treated versus untreated cells, HDAC 1 and 2 eluted in several peaks of deacetylase activity, assayed using mixed acetylated histones or acetylated histone H4 peptide. Stimulation of cells with okadaic acid led to hyperphosphorylation of HDAC 1 and 2 as well as changes in column elution of both enzymes. Hyperphosphorylated HDAC2 was also observed in cells synchronized with nocodazole or taxol, demonstrating regulation of HDAC phosphorylation during mitosis. Phosphorylated HDAC1 and 2 showed a gel mobility retardation that correlated with a small but significant increase in activity, both of which were reversed upon phosphatase treatment in vitro. However, the most pronounced effect of HDAC phosphorylation was to disrupt protein complex formation between HDAC1 and 2 as well as complex formation between HDAC1 and corepressors mSin3A and YY1. In contrast, interactions between HDAC1/2 and RbAp46/48 were unaffected by okadaic acid. These results establish a novel link between HDAC phosphorylation and the control of protein-protein interactions and suggest a mechanism for relief of deacetylase-catalyzed transcriptional repression by phosphorylation-dependent signaling.

Genome-Nuclear Lamina Interactions Regulate Cardiac Stem Cell Lineage Restriction.

PubMed

Poleshko, Andrey; Shah, Parisha P; Gupta, Mudit; Babu, Apoorva; Morley, Michael P; Manderfield, Lauren J; Ifkovits, Jamie L; Calderon, Damelys; Aghajanian, Haig; Sierra-Pagán, Javier E; Sun, Zheng; Wang, Qiaohong; Li, Li; Dubois, Nicole C; Morrisey, Edward E; Lazar, Mitchell A; Smith, Cheryl L; Epstein, Jonathan A; Jain, Rajan

2017-10-19

Progenitor cells differentiate into specialized cell types through coordinated expression of lineage-specific genes and modification of complex chromatin configurations. We demonstrate that a histone deacetylase (Hdac3) organizes heterochromatin at the nuclear lamina during cardiac progenitor lineage restriction. Specification of cardiomyocytes is associated with reorganization of peripheral heterochromatin, and independent of deacetylase activity, Hdac3 tethers peripheral heterochromatin containing lineage-relevant genes to the nuclear lamina. Deletion of Hdac3 in cardiac progenitor cells releases genomic regions from the nuclear periphery, leading to precocious cardiac gene expression and differentiation into cardiomyocytes; in contrast, restricting Hdac3 to the nuclear periphery rescues myogenesis in progenitors otherwise lacking Hdac3. Our results suggest that availability of genomic regions for activation by lineage-specific factors is regulated in part through dynamic chromatin-nuclear lamina interactions and that competence of a progenitor cell to respond to differentiation signals may depend upon coordinated movement of responding gene loci away from the nuclear periphery. Copyright © 2017 Elsevier Inc. All rights reserved.

Dissociation of muscle insulin sensitivity from exercise endurance in mice by HDAC3 depletion.

PubMed

Hong, Sungguan; Zhou, Wenjun; Fang, Bin; Lu, Wenyun; Loro, Emanuele; Damle, Manashree; Ding, Guolian; Jager, Jennifer; Zhang, Sisi; Zhang, Yuxiang; Feng, Dan; Chu, Qingwei; Dill, Brian D; Molina, Henrik; Khurana, Tejvir S; Rabinowitz, Joshua D; Lazar, Mitchell A; Sun, Zheng

2017-02-01

Type 2 diabetes and insulin resistance are associated with reduced glucose utilization in the muscle and poor exercise performance. Here we find that depletion of the epigenome modifier histone deacetylase 3 (HDAC3) specifically in skeletal muscle causes severe systemic insulin resistance in mice but markedly enhances endurance and resistance to muscle fatigue, despite reducing muscle force. This seemingly paradoxical phenotype is due to lower glucose utilization and greater lipid oxidation in HDAC3-depleted muscles, a fuel switch caused by the activation of anaplerotic reactions driven by AMP deaminase 3 (Ampd3) and catabolism of branched-chain amino acids. These findings highlight the pivotal role of amino acid catabolism in muscle fatigue and type 2 diabetes pathogenesis. Further, as genome occupancy of HDAC3 in skeletal muscle is controlled by the circadian clock, these results delineate an epigenomic regulatory mechanism through which the circadian clock governs skeletal muscle bioenergetics. These findings suggest that physical exercise at certain times of the day or pharmacological targeting of HDAC3 could potentially be harnessed to alter systemic fuel metabolism and exercise performance.

Dissociation of muscle insulin sensitivity from exercise endurance in mice by HDAC3

PubMed Central

Hong, Sungguan; Zhou, Wenjun; Fang, Bin; Lu, Wenyun; Loro, Emanuele; Damle, Manashree; Ding, Guolian; Jager, Jennifer; Zhang, Sisi; Zhang, Yuxiang; Feng, Dan; Chu, Qingwei; Dill, Brian D; Molina, Henrik; Khurana, Tejvir S; Rabinowitz, Joshua D; Lazar, Mitchell A; Sun, Zheng

2017-01-01

Type 2 diabetes (T2D) and insulin resistance are associated with reduced glucose utilization in the muscle and poor exercise performance. Here we find that depletion of an epigenome modifier, histone deacetylase 3 (HDAC3), specifically in skeletal muscle causes severe systemic insulin resistance in mice, but markedly enhances exercise endurance and muscle fatigue resistance, despite reducing muscle force. This seemingly paradoxical phenotype is due to lower glucose utilization and greater lipid oxidation in HDAC3-depleted muscles, a fuel switch caused by the activation of anaplerotic reactions driven by AMP deaminase 3 (Ampd3) and branched-chain amino acid catabolism. These findings highlight the pivotal role of amino acid catabolism in muscle fatigue and T2D pathogenesis. Further, as genome occupancy of HDAC3 in skeletal muscle is controlled by the circadian clock, these results delineate an epigenomic regulatory mechanism through which the circadian clock governs skeletal muscle bioenergetics. These findings suggest that physical exercise at certain times of the day or pharmacological targeting of HDAC3 could potentially be harnessed to alter systemic fuel metabolism and exercise performance. PMID:27991918

Quantitative Analysis of Global Proteome and Lysine Acetylome Reveal the Differential Impacts of VPA and SAHA on HL60 Cells.

PubMed

Zhu, Xiaoyu; Liu, Xin; Cheng, Zhongyi; Zhu, Jun; Xu, Lei; Wang, Fengsong; Qi, Wulin; Yan, Jiawei; Liu, Ning; Sun, Zimin; Liu, Huilan; Peng, Xiaojun; Hao, Yingchan; Zheng, Nan; Wu, Quan

2016-01-29

Valproic acid (VPA) and suberoylanilide hydroxamic acid (SAHA) are both HDAC inhibitors (HDACi). Previous studies indicated that both inhibitors show therapeutic effects on acute myeloid leukaemia (AML), while the differential impacts of the two different HDACi on AML treatment still remains elusive. In this study, using 3-plex SILAC based quantitative proteomics technique, anti-acetyllysine antibody based affinity enrichment, high resolution LC-MS/MS and intensive bioinformatic analysis, the quantitative proteome and acetylome in SAHA and VPA treated AML HL60 cells were extensively studied. In total, 5,775 proteins and 1,124 lysine acetylation sites were successfully obtained in response to VAP and SAHA treatment. It is found that VPA and SAHA treatment differently induced proteome and acetylome profiling in AML HL60 cells. This study revealed the differential impacts of VPA and SAHA on proteome/acetylome in AML cells, deepening our understanding of HDAC inhibitor mediated AML therapeutics.

HDAC6 deficiency or inhibition blocks FGFR3 accumulation and improves bone growth in a model of achondroplasia.

PubMed

Ota, Sara; Zhou, Zi-Qiang; Romero, Megan P; Yang, Guang; Hurlin, Peter J

2016-10-01

Mutations that cause increased and/or inappropriate activation of FGFR3 are responsible for a collection of short-limbed chondrodysplasias. These mutations can alter receptor trafficking and enhance receptor stability, leading to increased receptor accumulation and activity. Here, we show that wildtype and mutant activated forms of FGFR3 increase expression of the cytoplasmic deacetylase HDAC6 (Histone Deacetylase 6) and that FGFR3 accumulation is compromised in cells lacking HDAC6 or following treatment of fibroblasts or chondrocytes with small molecule inhibitors of HDAC6. The reduced accumulation of FGFR3 was linked to increased FGFR3 degradation that occurred through a lysosome-dependent mechanism. Using a mouse model of Thanatophoric Dysplasia Type II (TDII) we show that both HDAC6 deletion and treatment with the small molecule HDAC6 inhibitor tubacin reduced FGFR3 accumulation in the growth plate and improved endochondral bone growth. Defective endochondral growth in TDII is associated with reduced proliferation and poor hypertrophic differentiation and the improved bone growth was associated with increased chondrocyte proliferation and expansion of the differentiation compartment within the growth plate. These findings further define the mechanisms that control FGFR3 accumulation and contribute to skeletal pathology caused by mutations in FGFR3. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

dSAP18 and dHDAC1 contribute to the functional regulation of the Drosophila Fab-7 element.

PubMed

Canudas, Silvia; Pérez, Silvia; Fanti, Laura; Pimpinelli, Sergio; Singh, Navjot; Hanes, Steven D; Azorín, Fernando; Espinás, M Lluïsa

2005-01-01

It was described earlier that the Drosophila GAGA factor [Trithorax-like (Trl)] interacts with dSAP18, which, in mammals, was reported to be a component of the Sin3-HDAC co-repressor complex. GAGA-dSAP18 interaction was proposed to contribute to the functional regulation of the bithorax complex (BX-C). Here, we show that mutant alleles of Trl, dsap18 and drpd3/hdac1 enhance A6-to-A5 transformation indicating a contribution to the regulation of Abd-B expression at A6. In A6, expression of Abd-B is driven by the iab-6 enhancer, which is insulated from iab-7 by the Fab-7 element. Here, we report that GAGA, dSAP18 and dRPD3/HDAC1 co-localize to ectopic Fab-7 sites in polytene chromosomes and that mutant Trl, dsap18 and drpd3/hdac1 alleles affect Fab-7-dependent silencing. Consistent with these findings, chromatin immunoprecipitation analysis shows that, in Drosophila embryos, the endogenous Fab-7 element is hypoacetylated at histones H3 and H4. These results indicate a contribution of GAGA, dSAP18 and dRPD3/HDAC1 to the regulation of Fab-7 function.

Frontline Science: ATF3 is responsible for the inhibition of TNF-α release and the impaired migration of acute ethanol-exposed monocytes and macrophages.

PubMed

Hu, Chaojie; Meng, Xiaoming; Huang, Cheng; Shen, Chenlin; Li, Jun

2017-03-01

Binge drinking represses host innate immunity and leads to a high risk of infection. Acute EtOH-pretreated macrophages exhibit a decreased production of proinflammatory mediators in response to LPS. ATF3 is induced and counter-regulates the LPS/TLR4 inflammatory cascade. Here, we investigated the potential role of ATF3 in LPS tolerance in acute ethanol-pretreated macrophages. We found that there was an inverse correlation between ATF3 and LPS-induced TNF-α production in acute ethanol-pretreated murine monocytes and macrophages. The knockdown of ATF3 attenuated the inhibitory effects of acute ethanol treatment on LPS-induced TNF-α production. Furthermore, ChIP assays and co-IP demonstrated that ATF3, together with HDAC1, negatively modulated the transcription of TNF-α. In binge-drinking mice challenged with LPS, an up-regulation of ATF3 and HDAC1 and a concomitant decrease in TNF-α were observed. Given that HDAC1 was concomitantly induced in acute ethanol-exposed monocytes and macrophages, we used the HDACi TSA or silenced HDAC1 to explore the role of HDAC1 in acute ethanol-treated macrophages. Our results revealed that TSA treatment and HDAC1 knockdown prevented acute ethanol-induced ATF3 expression and the inhibition of TNF-α transcription. These data indicated a dual role for HDAC1 in acute ethanol-induced LPS tolerance. Furthermore, we showed that the induction of ATF3 led to the impaired migration of BM monocytes and macrophages. Overall, we present a novel role for ATF3 in the inhibition of LPS-induced TNF-α and in the impairment of monocyte and macrophage migration. © Society for Leukocyte Biology.

Discovery of HDAC Inhibitors That Lack an Active Site Zn(2+)-Binding Functional Group.

PubMed

Vickers, Chris J; Olsen, Christian A; Leman, Luke J; Ghadiri, M Reza

2012-06-14

Natural and synthetic histone deacetylase (HDAC) inhibitors generally derive their strong binding affinity and high potency from a key functional group that binds to the Zn(2+) ion within the enzyme active site. However, this feature is also thought to carry the potential liability of undesirable off-target interactions with other metalloenzymes. As a step toward mitigating this issue, here, we describe the design, synthesis, and structure-activity characterizations of cyclic α3β-tetrapeptide HDAC inhibitors that lack the presumed indispensable Zn(2+)-binding group. The lead compounds (e.g., 15 and 26) display good potency against class 1 HDACs and are active in tissue culture against various human cancer cell lines. Importantly, enzymological analysis of 26 indicates that the cyclic α3β-tetrapeptide is a fast-on/off competitive inhibitor of HDACs 1-3 with K i values of 49, 33, and 37 nM, respectively. Our proof of principle study supports the idea that novel classes of HDAC inhibitors, which interact at the active-site opening, but not with the active site Zn(2+), can have potential in drug design.

Inhibition of histone deacetylases protects septic mice from lung and splenic apoptosis.

PubMed

Takebe, Mariko; Oishi, Hirofumi; Taguchi, Kumiko; Aoki, Yuta; Takashina, Michinori; Tomita, Kengo; Yokoo, Hiroki; Takano, Yasuo; Yamazaki, Mitsuaki; Hattori, Yuichi

2014-04-01

Epigenetic programming, dynamically regulated by histone acetylation, may play a key role in the pathophysiology of sepsis. We examined whether histone deacetylase (HDAC) can contribute to sepsis-associated inflammation and apoptosis. Polymicrobial sepsis was induced by cecal ligation and puncture (CLP) in BALB/c mice. An intraperitoneal injection of CG200745 (10 mg/kg), a novel broad-spectrum HDAC inhibitor, or valproic acid (500 mg/kg), a predominant inhibitor of class I HDACs, was given 3 h before surgery. HDAC1, HDAC2, and HDAC3 protein levels were decreased in lungs after CLP. Furthermore, CLP-induced sepsis increased both histone H3 and H4 acetylation levels in lungs. When CG200745 was given, apoptosis induction was strongly suppressed in lungs and spleens of septic mice. This antiapoptotic effect of CG200745 was not accompanied by upregulation of antiapoptotic and downregulation of proapoptotic Bcl-2 family member proteins. Treatment with CG200745 failed to inhibit elevated levels of serum cytokines and prevent lung inflammation in septic mice. Valproic acid also showed antiapoptotic but not anti-inflammatory effects in septic mice. These findings imply that HDAC inhibitors are a unique agent to prevent cell apoptosis in sepsis at their doses that do not improve inflammatory features, indicating that septic inflammation and apoptosis may not necessarily be essential for one another's existence. This study also represents the first report that CLP-induced sepsis downregulates HDACs. Nevertheless, the data with HDAC inhibitors suggest that imbalance in histone acetylation may play a contributory role in expression or repression of genes involved in septic cell apoptosis. Copyright © 2014 Elsevier Inc. All rights reserved.

MAPK signaling pathways and HDAC3 activity are disrupted during differentiation of emerin-null myogenic progenitor cells

PubMed Central

Collins, Carol M.; Ellis, Joseph A.

2017-01-01

ABSTRACT Mutations in the gene encoding emerin cause Emery–Dreifuss muscular dystrophy (EDMD). Emerin is an integral inner nuclear membrane protein and a component of the nuclear lamina. EDMD is characterized by skeletal muscle wasting, cardiac conduction defects and tendon contractures. The failure to regenerate skeletal muscle is predicted to contribute to the skeletal muscle pathology of EDMD. We hypothesize that muscle regeneration defects are caused by impaired muscle stem cell differentiation. Myogenic progenitors derived from emerin-null mice were used to confirm their impaired differentiation and analyze selected myogenic molecular pathways. Emerin-null progenitors were delayed in their cell cycle exit, had decreased myosin heavy chain (MyHC) expression and formed fewer myotubes. Emerin binds to and activates histone deacetylase 3 (HDAC3). Here, we show that theophylline, an HDAC3-specific activator, improved myotube formation in emerin-null cells. Addition of the HDAC3-specific inhibitor RGFP966 blocked myotube formation and MyHC expression in wild-type and emerin-null myogenic progenitors, but did not affect cell cycle exit. Downregulation of emerin was previously shown to affect the p38 MAPK and ERK/MAPK pathways in C2C12 myoblast differentiation. Using a pure population of myogenic progenitors completely lacking emerin expression, we show that these pathways are also disrupted. ERK inhibition improved MyHC expression in emerin-null cells, but failed to rescue myotube formation or cell cycle exit. Inhibition of p38 MAPK prevented differentiation in both wild-type and emerin-null progenitors. These results show that each of these molecular pathways specifically regulates a particular stage of myogenic differentiation in an emerin-dependent manner. Thus, pharmacological targeting of multiple pathways acting at specific differentiation stages may be a better therapeutic approach in the future to rescue muscle regeneration in vivo. PMID:28188262

Expression of Histone Deacetylases in Cellular Compartments of the Mouse Brain and the Effects of Ischemia

PubMed Central

Bachleda, Amelia; Morrison, Richard S.; Murphy, Sean P.

2011-01-01

Drugs that inhibit specific histone deacetylase (HDAC) activities have enormous potential in preventing the consequences of acute injury to the nervous system and in allaying neurodegeneration. However, very little is known about the expression pattern of the HDACs in the central nervous system (CNS). Identifying the cell types that express HDACs in the CNS is important for determining therapeutic targets for HDAC inhibitors and evaluating potential side effects. We characterized the cellular expression of HDACs 1–3, and HDACs 4 and 6, in the adult mouse brain in the cingulate cortex, parietal cortex, dentate gyrus, and CA1 regions of the hippocampus and subcortical white matter. Expression of class I HDACs showed a cell-and region-specific pattern. Transient focal ischemia induced by temporary middle cerebral artery occlusion, or global ischemia induced by in vitro oxygen–glucose deprivation, altered the extent of HDAC expression in a region- and cell-specific manner. The pan-HDAC inhibitor, SAHA, reduced ischemia-induced alterations in HDACs. The results suggest that in addition to promoting epigenetic changes in transcriptional activity in the nucleus of neurons and glia, HDACs may also have non-transcriptional actions in axons and the distant processes of glial cells and may significantly modulate the response to injury in a cell- and region-specific manner. PMID:21966324

Discovery of selective small-molecule HDAC6 inhibitor for overcoming proteasome inhibitor resistance in multiple myeloma

PubMed Central

Hideshima, Teru; Paranal, Ronald M.; Tang, Weiping; Greenberg, Edward; West, Nathan; Colling, Meaghan E.; Estiu, Guillermina; Mazitschek, Ralph; Perry, Jennifer A.; Ohguchi, Hiroto; Cottini, Francesca; Mimura, Naoya; Görgün, Güllü; Tai, Yu-Tzu; Richardson, Paul G.; Carrasco, Ruben D.; Wiest, Olaf; Schreiber, Stuart L.; Anderson, Kenneth C.; Bradner, James E.

2016-01-01

Multiple myeloma (MM) has proven clinically susceptible to modulation of pathways of protein homeostasis. Blockade of proteasomal degradation of polyubiquitinated misfolded proteins by the proteasome inhibitor bortezomib (BTZ) achieves responses and prolongs survival in MM, but long-term treatment with BTZ leads to drug-resistant relapse in most patients. In a proof-of-concept study, we previously demonstrated that blocking aggresomal breakdown of polyubiquitinated misfolded proteins with the histone deacetylase 6 (HDAC6) inhibitor tubacin enhances BTZ-induced cytotoxicity in MM cells in vitro. However, these foundational studies were limited by the pharmacologic liabilities of tubacin as a chemical probe with only in vitro utility. Emerging from a focused library synthesis, a potent, selective, and bioavailable HDAC6 inhibitor, WT161, was created to study the mechanism of action of HDAC6 inhibition in MM alone and in combination with BTZ. WT161 in combination with BTZ triggers significant accumulation of polyubiquitinated proteins and cell stress, followed by caspase activation and apoptosis. More importantly, this combination treatment was effective in BTZ-resistant cells and in the presence of bone marrow stromal cells, which have been shown to mediate MM cell drug resistance. The activity of WT161 was confirmed in our human MM cell xenograft mouse model and established the framework for clinical trials of the combination treatment to improve patient outcomes in MM. PMID:27799547

Radio-sensitizing Effects of Novel Histone De-Acetylase Inhibitors in Prostate Cancer

DTIC Science & Technology

2007-03-01

were investigated in PC-3, LN -3 and DU-145 cells. (S)-HDAC-42 and SAHA could sensitize PC-3 and DU-145 cells to radiation. Aim 2: Effects of VAD- 18 ...combined effects of HDAC inhibitors and ionizing radiation on prostate cancer cell lines (PC-3, LN -3, LnCAP, DU-145 and 22Rv1). Aim 2. To understand the...cancer cell lines. Aim 3. To determine the combined effects of HDAC inhibitors plus ionizing radiation on the regression of (i) prostate cancer xenografts

Transcriptional repression of ER through hMAPK dependent histone deacetylation by class I HDACs.

PubMed

Plotkin, Amy; Volmar, Claude-Henry; Wahlestedt, Claes; Ayad, Nagi; El-Ashry, Dorraya

2014-09-01

Anti-estrogen therapies are not effective in ER- breast cancers, thus identifying mechanisms underlying lack of ER expression in ER- breast cancers is imperative. We have previously demonstrated that hyperactivation of MAPK (hMAPK) downstream of overexpressed EGFR or overexpression/amplification of Her2 represses ER protein and mRNA expression. Abrogation of hMAPK in ER- breast cancer cell lines and primary cultures causes re-expression of ER and restoration of anti-estrogen responses. This study was performed to identify mechanisms of hMAPK-induced transcriptional repression of ER. We found that ER promoter activity is significantly reduced in the presence of hMAPK signaling, yet did not identify specific promoter sequences responsible for this repression. We performed an epigenetic compound screen in an ER- breast cancer cell line that expresses hMAPK yet does not exhibit ER promoter hypermethylation. A number of HDAC inhibitors were identified and confirmed to modulate ER expression and estrogen signaling in multiple ER- cell lines and tumor samples lacking ER promoter methylation. siRNA-mediated knockdown of HDACs 1, 2, and 3 reversed the mRNA repression in multiple breast cancer cell lines and primary cultures and ER promoter-associated histone acetylation increased following MAPK inhibition. These data implicate histone deacetylation downstream of hMAPK in the observed ER mRNA repression associated with hMAPK. Importantly, histone deacetylation appears to be a common mechanism in the transcriptional repression of ER between ER- breast cancers with or without ER promoter hypermethylation.

Silencing of Histone Deacetylase 9 Expression in Podocytes Attenuates Kidney Injury in Diabetic Nephropathy

PubMed Central

Liu, Feng; Zong, Ming; Wen, Xiaofei; Li, Xuezhu; Wang, Jun; Wang, Yi; Jiang, Wei; Li, Xiaojun; Guo, Zhongliang; Qi, Hualin

2016-01-01

Podocyte dysfunction is important in the onset and development of diabetic nephropathy (DN). Histone deacetylases (HDACs) have been recently proved to play critical roles in the pathogenesis of DN. As one subtype of the class IIa HDACs, HDAC9 is capable to repress/de-repress their target genes in tumor, inflammation, atherosclerosis and metabolic diseases. In the present study, we investigate whether HDAC9 is involved in the pathophysiologic process of DN, especially the podocyte injury. Firstly, we explored the expression patterns and localization of HDAC9 and found that HDAC9 expression was significantly up-regulated in high glucose (HG)-treated mouse podocytes, as well as kidney tissues from diabetic db/db mice and patients with DN. Secondly, knockdown of HDAC9 in mouse podocytes significantly suppressed HG-induced reactive oxygen species (ROS) generation, cell apoptosis and inflammation through JAK2/STAT3 pathway and reduced the podocytes injury by decreasing the expression levels of Nephrin and Podocin. Moreover, in diabetic db/db mice, silencing of HDAC9 attenuated the glomerulosclerosis, inflammatory cytokine release, podocyte apoptosis and renal injury. Collectively, these data indicate that HDAC9 may be involved in the process of DN, especially podocyte injury. Our study suggest that inhibition of HDAC9 may have a therapeutic potential in DN treatment. PMID:27633396

Design, Synthesis and Biological Evaluation of Histone Deacetylase (HDAC) Inhibitors: Saha (Vorinostat) Analogs and Biaryl Indolyl Benzamide Inhibitors Display Isoform Selectivity

NASA Astrophysics Data System (ADS)

Negmeldin, Ahmed Thabet

HDAC proteins have emerged as interesting targets for anti-cancer drugs due to their involvement in cancers, as well as several other diseases. Several HDAC inhibitors have been approved by the FDA as anti-cancer drugs, including SAHA (suberoylanilide hydroxamic acid, Vorinostat). Unfortunately, SAHA inhibits most HDAC isoforms, which limit its use as a pharmacological tool and may lead to side effects in the clinic. In this work we were interested in developing isoform selective HDAC inhibitors, which may decrease or eliminate the side effects associated with non-selective inhibitors treatment. In addition, isoform selective HDAC inhibitors can be used as biological tools to help understand the HDAC-related cancer biology. Our strategy was based on synthesis and screening of several derivatives of the non-selective FDA approved drug SAHA substituted at different positions of the linker region. Several SAHA analogs modified at the C4 and C5 positions of the linker were synthesized. The new C4- and C5-modified SAHA libraries, along with the previously synthesized C2-modified SAHA analogs were screened in vitro and in cellulo for HDAC isoform selectivity. Interestingly, several analogs exhibited dual HDAC6/HDAC8 selectivity. Enantioselective syntheses of the pure enantiomers of some of the interesting analogs were performed and the enantiomers were screened in vitro. Among the most interesting analogs, ( R)-C4-benzyl SAHA displayed 520- to 1300-fold selectivity for HDAC6 and HDAC8 over HDAC1, 2, and 3, with IC50 values of 48 and 27 nM with HDAC6 and 8, respectively. Docking studies were performed to provide structural rationale for the observed selectivity of the new analogs. In addition, rational design, synthesis, and screening of several other biaryl indolyl benzamide HDAC inhibitors is discussed, and some showed modest HDAC1 selectivity. The new biaryl indolyl benzamides can be useful to further develop HDAC1 selective inhibitors. The dual HDAC6/8 selective inhibitors can be used as lead compounds and as a chemical tool to study HDAC related cancer biology. The observed enhancement of selectivity upon modifying the linker region of the non-selective inhibitor SAHA shows that modifying current drugs, like SAHA, could lead to substantial improvement in its pharmacodynamic properties.

Structural and Functional Analysis of the Human HDAC4 Catalytic Domain Reveals a Regulatory Structural Zinc-binding Domain*S⃞

PubMed Central

Bottomley, Matthew J.; Lo Surdo, Paola; Di Giovine, Paolo; Cirillo, Agostino; Scarpelli, Rita; Ferrigno, Federica; Jones, Philip; Neddermann, Petra; De Francesco, Raffaele; Steinkühler, Christian; Gallinari, Paola; Carfí, Andrea

2008-01-01

Histone deacetylases (HDACs) regulate chromatin status and gene expression, and their inhibition is of significant therapeutic interest. To date, no biological substrate for class IIa HDACs has been identified, and only low activity on acetylated lysines has been demonstrated. Here, we describe inhibitor-bound and inhibitor-free structures of the histone deacetylase-4 catalytic domain (HDAC4cd) and of an HDAC4cd active site mutant with enhanced enzymatic activity toward acetylated lysines. The structures presented, coupled with activity data, provide the molecular basis for the intrinsically low enzymatic activity of class IIa HDACs toward acetylated lysines and reveal active site features that may guide the design of class-specific inhibitors. In addition, these structures reveal a conformationally flexible structural zinc-binding domain conserved in all class IIa enzymes. Importantly, either the mutation of residues coordinating the structural zinc ion or the binding of a class IIa selective inhibitor prevented the association of HDAC4 with the N-CoR·HDAC3 repressor complex. Together, these data suggest a key role of the structural zinc-binding domain in the regulation of class IIa HDAC functions. PMID:18614528

Structural and functional analysis of the human HDAC4 catalytic domain reveals a regulatory structural zinc-binding domain.

PubMed

Bottomley, Matthew J; Lo Surdo, Paola; Di Giovine, Paolo; Cirillo, Agostino; Scarpelli, Rita; Ferrigno, Federica; Jones, Philip; Neddermann, Petra; De Francesco, Raffaele; Steinkühler, Christian; Gallinari, Paola; Carfí, Andrea

2008-09-26

Histone deacetylases (HDACs) regulate chromatin status and gene expression, and their inhibition is of significant therapeutic interest. To date, no biological substrate for class IIa HDACs has been identified, and only low activity on acetylated lysines has been demonstrated. Here, we describe inhibitor-bound and inhibitor-free structures of the histone deacetylase-4 catalytic domain (HDAC4cd) and of an HDAC4cd active site mutant with enhanced enzymatic activity toward acetylated lysines. The structures presented, coupled with activity data, provide the molecular basis for the intrinsically low enzymatic activity of class IIa HDACs toward acetylated lysines and reveal active site features that may guide the design of class-specific inhibitors. In addition, these structures reveal a conformationally flexible structural zinc-binding domain conserved in all class IIa enzymes. Importantly, either the mutation of residues coordinating the structural zinc ion or the binding of a class IIa selective inhibitor prevented the association of HDAC4 with the N-CoR.HDAC3 repressor complex. Together, these data suggest a key role of the structural zinc-binding domain in the regulation of class IIa HDAC functions.

Histone Deacetylase Inhibitor Trichostatin a Promotes the Apoptosis of Osteosarcoma Cells through p53 Signaling Pathway Activation

PubMed Central

Deng, Zhantao; Liu, Xiaozhou; Jin, Jiewen; Xu, Haidong; Gao, Qian; Wang, Yong; Zhao, Jianning

2016-01-01

Purpose: The purpose of this study was to investigate the profile of histone deacetylase (HDAC) activity and expression in osteosarcoma cells and tissues from osteosarcoma patients and to examine the mechanism by which a histone deacetylase (HDAC) inhibitor, Trichostatin A (TSA), promotes the apoptosis of osteosarcoma cells. Methods: HDAC activity and histone acetyltransferase (HAT) activity were determined in nuclear extracts of MG63 cells, hFOB 1.19 cells and tissues from 6 patients with primary osteosarcoma. The protein expression of Class I HDACs (1, 2, 3 and 8) and the activation of the p53 signaling pathway were examined by Western blot. Cell growth and apoptosis were determined by 3-(4, 5-dimethyl-2-thiazolyl)-2H-tetrazolium bromide (MTT) assay and flow cytometry, respectively. Results: Nuclear HDAC activity and class I HDAC expression were significantly higher in MG63 cells than in hFOB 1.19 cells, and a similar trend was observed in the human osteosarcoma tissues compared with the paired adjacent non-cancerous tissues. TSA significantly inhibited the growth of MG63 cells and promoted apoptosis in a dose-dependent manner through p53 signaling pathway activation. Conclusion: Class I HDACs play a central role in the pathogenesis of osteosarcoma, and HDAC inhibitors may thus have promise as new therapeutic agents against osteosarcoma. PMID:27877082

Distinct functional and temporal requirements for zebrafish Hdac1 during neural crest-derived craniofacial and peripheral neuron development.

PubMed

Ignatius, Myron S; Unal Eroglu, Arife; Malireddy, Smitha; Gallagher, Glen; Nambiar, Roopa M; Henion, Paul D

2013-01-01

The regulation of gene expression is accomplished by both genetic and epigenetic means and is required for the precise control of the development of the neural crest. In hdac1(b382) mutants, craniofacial cartilage development is defective in two distinct ways. First, fewer hoxb3a, dlx2 and dlx3-expressing posterior branchial arch precursors are specified and many of those that are consequently undergo apoptosis. Second, in contrast, normal numbers of progenitors are present in the anterior mandibular and hyoid arches, but chondrocyte precursors fail to terminally differentiate. In the peripheral nervous system, there is a disruption of enteric, DRG and sympathetic neuron differentiation in hdac1(b382) mutants compared to wildtype embryos. Specifically, enteric and DRG-precursors differentiate into neurons in the anterior gut and trunk respectively, while enteric and DRG neurons are rarely present in the posterior gut and tail. Sympathetic neuron precursors are specified in hdac1(b382) mutants and they undergo generic neuronal differentiation but fail to undergo noradrenergic differentiation. Using the HDAC inhibitor TSA, we isolated enzyme activity and temporal requirements for HDAC function that reproduce hdac1(b382) defects in craniofacial and sympathetic neuron development. Our study reveals distinct functional and temporal requirements for zebrafish hdac1 during neural crest-derived craniofacial and peripheral neuron development.

Murine craniofacial development requires Hdac3-mediated repression of Msx gene expression

PubMed Central

Singh, Nikhil; Gupta, Mudit; Trivedi, Chinmay M.; Singh, Manvendra K.; Li, Li; Epstein, Jonathan A.

2013-01-01

Craniofacial development is characterized by reciprocal interactions between neural crest cells and neighboring cell populations of ectodermal, endodermal and mesodermal origin. Various genetic pathways play critical roles in coordinating the development of cranial structures by modulating the growth, survival and differentiation of neural crest cells. However, the regulation of these pathways, particularly at the epigenomic level, remains poorly understood. Using murine genetics, we show that neural crest cells exhibit a requirement for the class I histone deacetylase Hdac3 during craniofacial development. Mice in which Hdac3 has been conditionally deleted in neural crest demonstrate fully penetrant craniofacial abnormalities, including microcephaly, cleft secondary palate and dental hypoplasia. Consistent with these abnormalities, we observe dysregulation of cell cycle genes and increased apoptosis in neural crest structures in mutant embryos. Known regulators of cell cycle progression and apoptosis in neural crest, including Msx1, Msx2 and Bmp4, are upregulated in Hdac3-deficient cranial mesenchyme. These results suggest that Hdac3 serves as a critical regulator of craniofacial morphogenesis, in part by repressing core apoptotic pathways in cranial neural crest cells. PMID:23506836

Conditional deletion of Hdac3 in osteoprogenitor cells attenuates diet-induced systemic metabolic dysfunction

PubMed Central

McGee-Lawrence, Meghan E.; White, Thomas A.; LeBrasseur, Nathan K.; Westendorf, Jennifer J.

2015-01-01

Obesity is a major health epidemic in the United States and a leading cause of preventable diseases including type 2 diabetes. A growing body of evidence indicates that the skeleton influences whole body metabolism and suggests a new avenue for developing novel therapeutic agents, but the underlying mechanisms are not well understood. Here, it is demonstrated that conditional deletion of an epigenetic regulator, Hdac3, in osteoblast progenitor cells abrogates high fat diet-induced insulin resistance and hepatic steatosis. These Hdac3-deficient mice have reduced bone formation and lower circulating levels of total and undercarboxylated osteocalcin, coupled with decreased bone resorption activity. They also maintain lower body fat and fasting glucose levels on normal and high fat chow diets. The mechanisms by which Hdac3 controls systemic energy homeostasis from within osteoblasts have not yet been fully realized, but the current study suggests that it does not involve elevated levels of circulating osteocalcin. Thus, Hdac3 is a new player in the emerging paradigm that the skeleton influences systemic energy metabolism. PMID:25666992

Histone deacetylase 6 controls Notch3 trafficking and degradation in T-cell acute lymphoblastic leukemia cells.

PubMed

Pinazza, Marica; Ghisi, Margherita; Minuzzo, Sonia; Agnusdei, Valentina; Fossati, Gianluca; Ciminale, Vincenzo; Pezzè, Laura; Ciribilli, Yari; Pilotto, Giorgia; Venturoli, Carolina; Amadori, Alberto; Indraccolo, Stefano

2018-04-12

Several studies have revealed that endosomal sorting controls the steady-state levels of Notch at the cell surface in normal cells and prevents its inappropriate activation in the absence of ligands. However, whether this highly dynamic physiologic process can be exploited to counteract dysregulated Notch signaling in cancer cells remains unknown. T-ALL is a malignancy characterized by aberrant Notch signaling, sustained by activating mutations in Notch1 as well as overexpression of Notch3, a Notch paralog physiologically subjected to lysosome-dependent degradation in human cancer cells. Here we show that treatment with the pan-HDAC inhibitor Trichostatin A (TSA) strongly decreases Notch3 full-length protein levels in T-ALL cell lines and primary human T-ALL cells xenografted in mice without substantially reducing NOTCH3 mRNA levels. Moreover, TSA markedly reduced the levels of Notch target genes, including pTα, CR2, and DTX-1, and induced apoptosis of T-ALL cells. We further observed that Notch3 was post-translationally regulated following TSA treatment, with reduced Notch3 surface levels and increased accumulation of Notch3 protein in the lysosomal compartment. Surface Notch3 levels were rescued by inhibition of dynein with ciliobrevin D. Pharmacologic studies with HDAC1, 6, and 8-specific inhibitors disclosed that these effects were largely due to inhibition of HDAC6 in T-ALL cells. HDAC6 silencing by specific shRNA was followed by reduced Notch3 expression and increased apoptosis of T-ALL cells. Finally, HDAC6 silencing impaired leukemia outgrowth in mice, associated with reduction of Notch3 full-length protein in vivo. These results connect HDAC6 activity to regulation of total and surface Notch3 levels and suggest HDAC6 as a potential novel therapeutic target to lower Notch signaling in T-ALL and other Notch3-addicted tumors.

Synthesis, antimalarial properties, and SAR studies of alkoxyurea-based HDAC inhibitors.

PubMed

Hansen, Finn K; Skinner-Adams, Tina S; Duffy, Sandra; Marek, Linda; Sumanadasa, Subathdrage D M; Kuna, Krystina; Held, Jana; Avery, Vicky M; Andrews, Katherine T; Kurz, Thomas

2014-03-01

Histone deacetylase (HDAC) inhibitors are an emerging class of potential antimalarial drugs. We investigated the antiplasmodial properties of 16 alkoxyurea-based HDAC inhibitors containing various cap and zinc binding groups (ZBGs). Ten compounds displayed sub-micromolar activity against the 3D7 line of Plasmodium falciparum. Structure-activity relationship studies revealed that a hydroxamic acid ZBG is crucial for antiplasmodial activity, and that the introduction of bulky alkyl substituents to cap groups increases potency against asexual blood-stage parasites. We also demonstrate that selected compounds cause hyperacetylation of P. falciparum histone H4, indicating inhibition of one or more PfHDACs. To assess the selectivity of alkoxyurea-based HDAC inhibitors for parasite over normal mammalian cells, the cytotoxicity of representative compounds was evaluated against neonatal foreskin fibroblast (NFF) cells. The most active compound, 6-((3-(4-(tert-butyl)phenyl)ureido)oxy)-N-hydroxyhexanamide (1 e, Pf3D7 IC50 : 0.16 μM) was 31-fold more toxic against the asexual blood stages than towards normal mammalian cells. Moreover, a subset of four structurally diverse HDAC inhibitors revealed moderate activity against late-stage (IV-V) gametocytes. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

The antiparasitic clioquinol induces apoptosis in leukemia and myeloma cells by inhibiting histone deacetylase activity.

PubMed

Cao, Biyin; Li, Jie; Zhu, Jingyu; Shen, Mingyun; Han, Kunkun; Zhang, Zubin; Yu, Yang; Wang, Yali; Wu, Depei; Chen, Suning; Sun, Aining; Tang, Xiaowen; Zhao, Yun; Qiao, Chunhua; Hou, Tingjun; Mao, Xinliang

2013-11-22

The antiparasitic clioquinol (CQ) represents a class of novel anticancer drugs by interfering with proteasome activity. In the present study, we found that CQ induced blood cancer cell apoptosis by inhibiting histone deacetylases (HDACs). CQ accumulated the acetylation levels of several key proteins including histone H3 (H3), p53, HSP90, and α-tubulin. In the mechanistic study, CQ was found to down-regulate HDAC1, -3, -4, and -5 in both myeloma and leukemia cells. Computer modeling analysis revealed that CQ was well docked into the active pocket of the enzyme, where the oxygen and nitrogen atoms in CQ formed stable coordinate bonds with the zinc ion, and the hydroxyl group from CQ formed an effective hydrogen bond with Asp-267. Moreover, co-treatment with CQ and zinc/copper chloride led to decreased Ac-H3. Furthermore, CQ inhibited the activity of Class I and IIa HDACs in the cell-free assays, demonstrating that CQ interfered with HDAC activity. By inhibiting HDAC activity, CQ induced expression of p21, p27, and p53, cell cycle arrest at G1 phase, and cell apoptosis. This study suggested that the HDAC enzymes are targets of CQ, which provided a novel insight into the molecular mechanism of CQ in the treatment of hematological malignancies.

Functional analysis of histone deacetylase and its role in stress response, drug resistance and solid-state cultivation in Aspergillus oryzae.

PubMed

Kawauchi, Moriyuki; Iwashita, Kazuhiro

2014-08-01

In the eukaryotic cell, histone deacetylases (HDACs) play key roles in the regulation of fundamental cellular process such as development regulation, stress response, secondary metabolism and genome integrity. Here, we provide a comprehensive phenotypic analysis using HDAC disruptants in Aspergillus oryzae. Our study revealed that four HDACs, hdaA/Aohda1, hdaB/Aorpd3, hdaD/Aohos2 and hst4/AohstD were involved in stress response, cell wall synthesis and chromatin integrity in A. oryzae. Osmotic stress sensitivity of HDAC disruptants differed between plate cultures and liquid cultures, suggesting that HDACs adapt to the difference environmental conditions. Using a common A. oryzae fermentation medium, rice-koji, we also characterized HDACs related to growth and enzyme production to investigate which HDACs will be required for adaptation to environmental conditions and stress resistances. Because HDACs are widely conserved, our study has broad applications and may inform work with filamentous fungi and other eukaryote. Copyright © 2014 The Society for Biotechnology, Japan. Published by Elsevier B.V. All rights reserved.

Valproic acid attenuates acute lung injury induced by ischemia-reperfusion in rats.

PubMed

Wu, Shu-Yu; Tang, Shih-En; Ko, Fu-Chang; Wu, Geng-Chin; Huang, Kun-Lun; Chu, Shi-Jye

2015-06-01

Evidence reveals that histone deacetylase (HDAC) inhibition has potential for the treatment of inflammatory diseases. The protective effect of HDAC inhibition involves multiple mechanisms. Heme oxygenase-1 (HO-1) is protective in lung injury as a key regulator of antioxidant response. The authors examined whether HDAC inhibition provided protection against ischemia-reperfusion (I/R) lung injury in rats by up-regulating HO-1 activity. Acute lung injury was induced by producing 40 min of ischemia followed by 60 min of reperfusion in isolated perfused rat lungs. The rats were randomly allotted to control group, I/R group, or I/R + valproic acid (VPA) group with or without an HO-1 activity inhibitor (zinc protoporphyrin IX) (n = 6 per group). I/R caused significant increases in the lung edema, pulmonary arterial pressure, lung injury scores, tumor necrosis factor-α, and cytokine-induced neutrophil chemoattractant-1 concentrations in bronchoalveolar lavage fluid. Malondialdehyde levels, carbonyl contents, and myeloperoxidase-positive cells in lung tissue were also significantly increased. I/R stimulated the degradation of inhibitor of nuclear factor-κB-α, nuclear translocation of nuclear factor-κB, and up-regulation of HO-1 activity. Furthermore, I/R decreased B-cell lymphoma-2, heat shock protein 70, acetylated histone H3 protein expression, and increased the caspase-3 activity in the rat lungs. In contrast, VPA treatment significantly attenuated all the parameters of lung injury, oxidative stress, apoptosis, and inflammation. In addition, VPA treatment also enhanced HO-1 activity. Treatment with zinc protoporphyrin IX blocked the protective effect of VPA. VPA protected against I/R-induced lung injury. The protective mechanism may be partly due to enhanced HO-1 activity following HDAC inhibition.

Class I and II histone deacetylase expression in human chronic periodontitis gingival tissue.

PubMed

Cantley, M D; Dharmapatni, A A S S K; Algate, K; Crotti, T N; Bartold, P M; Haynes, D R

2016-04-01

Histone deacetylase inhibitors (HDACi) are being considered to treat chronic inflammatory diseases at low doses. Currently HDACi that are more specific are being developed to target particular HDACs; therefore, this study aimed to determine levels and distribution of class I and II HDAC in human gingival samples obtained from patients with chronic periodontitis. Gingival biopsies were obtained from patients with and without (mild inflammation, no bone loss) periodontitis. Total RNA was isolated for real-time quantitative polymerase chain reaction to determine expression of HDACs 1-10. Immunohistochemistry was used to determine protein distribution of HDACs 1, 5, 8 and 9. Factor VIII, CD3 and tartrate resistant acid phosphatase (TRAP) were detected in serial sections to identify blood vessels, lymphocytes, pre-osteoclasts and osteoclasts cells respectively. Tumour necrosis factor α (TNF-α) expression was also assessed. mRNA for HDAC 1, 5, 8 and 9 were significantly upregulated in chronic periodontitis gingival tissues compared to non-periodontitis samples (p < 0.05). Significantly higher HDAC 1 protein expression was observed in chronic periodontitis samples (p < 0.05), and was associated with CD3, TRAP and TNF-α-positive cells. HDAC 1, 5, 8 and 9 were expressed strongly by the factor VIII-positive microvasculature in the chronic periodontitis gingival tissues. HDAC 1, 5, 8 and 9 expression was higher in gingival tissues from patients with chronic periodontitis compared to non-periodontitis samples. Results suggest that these HDACs could therefore be targeted with specific acting HDACi. © 2015 John Wiley & Sons A/S. Published by John Wiley & Sons Ltd.

Inhibitors of histone demethylation and histone deacetylation cooperate in regulating gene expression and inhibiting growth in human breast cancer cells

PubMed Central

Vasilatos, Shauna N.; Boric, Lamia; Shaw, Patrick G.; Davidson, Nancy E.

2013-01-01

Abnormal activities of histone lysine demethylases (KDMs) and lysine deacetylases (HDACs) are associated with aberrant gene expression in breast cancer development. However, the precise molecular mechanisms underlying the crosstalk between KDMs and HDACs in chromatin remodeling and regulation of gene transcription are still elusive. In this study, we showed that treatment of human breast cancer cells with inhibitors targeting the zinc cofactor dependent class I/II HDAC, but not NAD+ dependent class III HDAC, led to significant increase of H3K4me2 which is a specific substrate of histone lysine-specific demethylase 1 (LSD1) and a key chromatin mark promoting transcriptional activation. We also demonstrated that inhibition of LSD1 activity by a pharmacological inhibitor, pargyline, or siRNA resulted in increased acetylation of H3K9 (AcH3K9). However, siRNA knockdown of LSD2, a homolog of LSD1, failed to alter the level of AcH3K9, suggesting that LSD2 activity may not be functionally connected with HDAC activity. Combined treatment with LSD1 and HDAC inhibitors resulted in enhanced levels of H3K4me2 and AcH3K9, and exhibited synergistic growth inhibition of breast cancer cells. Finally, microarray screening identified a unique subset of genes whose expression was significantly changed by combination treatment with inhibitors of LSD1 and HDAC. Our study suggests that LSD1 intimately interacts with histone deacetylases in human breast cancer cells. Inhibition of histone demethylation and deacetylation exhibits cooperation and synergy in regulating gene expression and growth inhibition, and may represent a promising and novel approach for epigenetic therapy of breast cancer. PMID:21452019

Histone deacetylase inhibitors: Potential in cancer therapy.

PubMed

Marks, P A; Xu, W-S

2009-07-01

The role of histone deacetylases (HDAC) and the potential of these enzymes as therapeutic targets for cancer, neurodegenerative diseases and a number of other disorders is an area of rapidly expanding investigation. There are 18 HDACs in humans. These enzymes are not redundant in function. Eleven of the HDACs are zinc dependent, classified on the basis of homology to yeast HDACs: Class I includes HDACs 1, 2, 3, and 8; Class IIA includes HDACs 4, 5, 7, and 9; Class IIB, HDACs 6 and 10; and Class IV, HDAC 11. Class III HDACs, sirtuins 1-7, have an absolute requirement for NAD(+), are not zinc dependent and generally not inhibited by compounds that inhibit zinc dependent deacetylases. In addition to histones, HDACs have many nonhistone protein substrates which have a role in regulation of gene expression, cell proliferation, cell migration, cell death, and angiogenesis. HDAC inhibitors (HDACi) have been discovered of different chemical structure. HDACi cause accumulation of acetylated forms of proteins which can alter their structure and function. HDACi can induce different phenotypes in various transformed cells, including growth arrest, apoptosis, reactive oxygen species facilitated cell death and mitotic cell death. Normal cells are relatively resistant to HDACi induced cell death. Several HDACi are in various stages of development, including clinical trials as monotherapy and in combination with other anti-cancer drugs and radiation. The first HDACi approved by the FDA for cancer therapy is suberoylanilide hydroxamic acid (SAHA, vorinostat, Zolinza), approved for treatment of cutaneous T-cell lymphoma. 2009 Wiley-Liss, Inc.

Histone deacetylases in memory and cognition.

PubMed

Penney, Jay; Tsai, Li-Huei

2014-12-09

Over the past 30 years, lysine acetylation of histone and nonhistone proteins has become established as a key modulator of gene expression regulating numerous aspects of cell biology. Neuronal growth and plasticity are no exception; roles for lysine acetylation and deacetylation in brain function and dysfunction continue to be uncovered. Transcriptional programs coupling synaptic activity to changes in gene expression are critical to the plasticity mechanisms underlying higher brain functions. These transcriptional programs can be modulated by changes in histone acetylation, and in many cases, transcription factors and histone-modifying enzymes are recruited together to plasticity-associated genes. Lysine acetylation, catalyzed by lysine acetyltransferases (KATs), generally promotes cognitive performance, whereas the opposing process, catalyzed by histone lysine deacetylases (HDACs), appears to negatively regulate cognition in multiple brain regions. Consistently, mutation or deregulation of different KATs or HDACs contributes to neurological dysfunction and neurodegeneration. HDAC inhibitors have shown promise as a treatment to combat the cognitive decline associated with aging and neurodegenerative disease, as well as to ameliorate the symptoms of depression and posttraumatic stress disorder, among others. In this review, we discuss the evidence for the roles of HDACs in cognitive function as well as in neurological disorders and disease. In particular, we focus on HDAC2, which plays a central role in coupling lysine acetylation to synaptic plasticity and mediates many of the effects of HDAC inhibition in cognition and disease. Copyright © 2014, American Association for the Advancement of Science.

Structure optimization and preliminary bioactivity evaluation of N-hydroxybenzamide-based HDAC inhibitors with Y-shaped cap.

PubMed

Yu, Chenggong; He, Feng; Qu, Ying; Zhang, Qiuqiong; Lv, Jiahui; Zhang, Xiangna; Xu, Ana; Miao, Pannan; Wu, Jingde

2018-05-01

Histone deacetylase inhibitors (HDACIs) are effective small molecules in the treatment of human cancers. In our continuing efforts to develop novel N-hydroxyterephthalamide-based HDACIs, herein we report the design and development of a new class of N-hydroxybenzamide-based HDACIs. In this new class of analogs, we inserted an ethylene moiety in the linker and used indole as a part of the Y-shaped cap group. Biological characterization identified compounds 4o, 4p, 4q and 4t to show improved HDAC inhibition, while no isoform selectivity for HDACs was observed. These compounds also exhibited improved anti-proliferative activity against multiple cancer cell lines when compared to their parent compound and positive control SAHA. Copyright © 2018 Elsevier Ltd. All rights reserved.

Treatment with 1,25(OH)2D3induced HDAC2 expression and reduced NF-κB p65 expression in a rat model of OVA-induced asthma

PubMed Central

Zhou, Y.; Wang, G.F.; Yang, L.; Liu, F.; Kang, J.Q.; Wang, R.L.; Gu, W.; Wang, C.Y.

2015-01-01

Recent evidence indicates that a deficiency of 1,25-dihydroxyvitamin D3 (1,25[OH]2D3) may influence asthma pathogenesis; however, its roles in regulating specific molecular transcription mechanisms remain unclear. We aimed to investigate the effect of 1,25(OH)2D3 on the expression and enzyme activity of histone deacetylase 2 (HDAC2) and its synergistic effects with dexamethasone (Dx) in the inhibition of inflammatory cytokine secretion in a rat asthma model. Healthy Wistar rats were randomly divided into 6 groups: control, asthma, 1,25(OH)2D3 pretreatment, 1,25(OH)2D3 treatment, Dx treatment, and Dx and 1,25(OH)2D3 treatment. Pulmonary inflammation was induced by ovalbumin (OVA) sensitization and challenge (OVA/OVA). Inflammatory cells and cytokines in the bronchoalveolar lavage (BAL) fluid and histological changes in lung tissue were examined. Nuclear factor kappa B (NF-κB) p65 and HDAC2 expression levels were assessed with Western blot analyses and quantitative reverse-transcriptase polymerase chain reaction (qRT-PCR). Enzyme activity measurements and immunohistochemical detection of HDAC2 were also performed. Our data demonstrated that 1,25(OH)2D3 reduced the airway inflammatory response and the level of inflammatory cytokines in BAL. Although NF-κB p65 expression was attenuated in the pretreatment and treatment groups, the expression and enzyme activity of HDAC2 were increased. In addition, 1,25(OH)2D3 and Dx had synergistic effects on the suppression of total cell infusion, cytokine release, and NF-κB p65 expression, and they also increased HDAC2 expression and activity in OVA/OVA rats. Collectively, our results indicated that 1,25(OH)2D3might be useful as a novel HDAC2 activator in the treatment of asthma. PMID:25923460

A Class 1 Histone Deacetylase with Potential as an Antifungal Target.

PubMed

Bauer, Ingo; Varadarajan, Divyavaradhi; Pidroni, Angelo; Gross, Silke; Vergeiner, Stefan; Faber, Birgit; Hermann, Martin; Tribus, Martin; Brosch, Gerald; Graessle, Stefan

2016-11-01

Histone deacetylases (HDACs) remove acetyl moieties from lysine residues at histone tails and nuclear regulatory proteins and thus significantly impact chromatin remodeling and transcriptional regulation in eukaryotes. In recent years, HDACs of filamentous fungi were found to be decisive regulators of genes involved in pathogenicity and the production of important fungal metabolites such as antibiotics and toxins. Here we present proof that one of these enzymes, the class 1 type HDAC RpdA, is of vital importance for the opportunistic human pathogen Aspergillus fumigatus Recombinant expression of inactivated RpdA shows that loss of catalytic activity is responsible for the lethal phenotype of Aspergillus RpdA null mutants. Furthermore, we demonstrate that a fungus-specific C-terminal region of only a few acidic amino acids is required for both the nuclear localization and catalytic activity of the enzyme in the model organism Aspergillus nidulans Since strains with single or multiple deletions of other classical HDACs revealed no or only moderate growth deficiencies, it is highly probable that the significant delay of germination and the growth defects observed in strains growing under the HDAC inhibitor trichostatin A are caused primarily by inhibition of catalytic RpdA activity. Indeed, even at low nanomolar concentrations of the inhibitor, the catalytic activity of purified RpdA is considerably diminished. Considering these results, RpdA with its fungus-specific motif represents a promising target for novel HDAC inhibitors that, in addition to their increasing impact as anticancer drugs, might gain in importance as antifungals against life-threatening invasive infections, apart from or in combination with classical antifungal therapy regimes. This paper reports on the fungal histone deacetylase RpdA and its importance for the viability of the fungal pathogen Aspergillus fumigatus and other filamentous fungi, a finding that is without precedent in other eukaryotic pathogens. Our data clearly indicate that loss of RpdA activity, as well as depletion of the enzyme in the nucleus, results in lethality of the corresponding Aspergillus mutants. Interestingly, both catalytic activity and proper cellular localization depend on the presence of an acidic motif within the C terminus of RpdA-type enzymes of filamentous fungi that is missing from the homologous proteins of yeasts and higher eukaryotes. The pivotal role, together with the fungus-specific features, turns RpdA into a promising antifungal target of histone deacetylase inhibitors, a class of molecules that is successfully used for the treatment of certain types of cancer. Indeed, some of these inhibitors significantly delay the germination and growth of different filamentous fungi via inhibition of RpdA. Upcoming analyses of clinically approved and novel inhibitors will elucidate their therapeutic potential as new agents for the therapy of invasive fungal infections-an interesting aspect in light of the rising resistance of fungal pathogens to conventional therapies. Copyright © 2016 Bauer et al.

Activation of p53 Transcriptional Activity by SMRT: a Histone Deacetylase 3-Independent Function of a Transcriptional Corepressor

PubMed Central

Adikesavan, Anbu Karani; Karmakar, Sudipan; Pardo, Patricia; Wang, Liguo; Liu, Shuang; Li, Wei

2014-01-01

The silencing mediator of retinoic acid and thyroid hormone receptors (SMRT) is an established histone deacetylase 3 (HDAC3)-dependent transcriptional corepressor. Microarray analyses of MCF-7 cells transfected with control or SMRT small interfering RNA revealed SMRT regulation of genes involved in DNA damage responses, and the levels of the DNA damage marker γH2AX as well as poly(ADP-ribose) polymerase cleavage were elevated in SMRT-depleted cells treated with doxorubicin. A number of these genes are established p53 targets. SMRT knockdown decreased the activity of two p53-dependent reporter genes as well as the expression of p53 target genes, such as CDKN1A (which encodes p21). SMRT bound directly to p53 and was recruited to p53 binding sites within the p21 promoter. Depletion of GPS2 and TBL1, components of the SMRT corepressor complex, but not histone deacetylase 3 (HDAC3) decreased p21-luciferase activity. p53 bound to the SMRT deacetylase activation domain (DAD), which mediates HDAC3 binding and activation, and HDAC3 could attenuate p53 binding to the DAD region of SMRT. Moreover, an HDAC3 binding-deficient SMRT DAD mutant coactivated p53 transcriptional activity. Collectively, these data highlight a biological role for SMRT in mediating DNA damage responses and suggest a model where p53 binding to the DAD limits HDAC3 interaction with this coregulator, thereby facilitating SMRT coactivation of p53-dependent gene expression. PMID:24449765

Identification of Components of the Murine Histone Deacetylase 6 Complex: Link between Acetylation and Ubiquitination Signaling Pathways

PubMed Central

Seigneurin-Berny, Daphné; Verdel, André; Curtet, Sandrine; Lemercier, Claudie; Garin, Jérôme; Rousseaux, Sophie; Khochbin, Saadi

2001-01-01

The immunopurification of the endogenous cytoplasmic murine histone deacetylase 6 (mHDAC6), a member of the class II HDACs, from mouse testis cytosolic extracts allowed the identification of two associated proteins. Both were mammalian homologues of yeast proteins known to interact with each other and involved in the ubiquitin signaling pathway: p97/VCP/Cdc48p, a homologue of yeast Cdc48p, and phospholipase A2-activating protein, a homologue of yeast UFD3 (ubiquitin fusion degradation protein 3). Moreover, in the C-terminal region of mHDAC6, a conserved zinc finger-containing domain named ZnF-UBP, also present in several ubiquitin-specific proteases, was discovered and was shown to mediate the specific binding of ubiquitin by mHDAC6. By using a ubiquitin pull-down approach, nine major ubiquitin-binding proteins were identified in mouse testis cytosolic extracts, and mHDAC6 was found to be one of them. All of these findings strongly suggest that mHDAC6 could be involved in the control of protein ubiquitination. The investigation of biochemical properties of the mHDAC6 complex in vitro further supported this hypothesis and clearly established a link between protein acetylation and protein ubiquitination. PMID:11689694

Histone deacetylation contributes to low extracellular superoxide dismutase expression in human idiopathic pulmonary arterial hypertension

PubMed Central

Woods, Crystal; Stearman, Robert S.; Venkataraman, Sujatha; Ferguson, Bradley S.; Swain, Kalin; Bowler, Russell P.; Geraci, Mark W.; Ihida-Stansbury, Kaori; Stenmark, Kurt R.; McKinsey, Timothy A.; Domann, Frederick E.

2016-01-01

Epigenetic mechanisms, including DNA methylation and histone acetylation, regulate gene expression in idiopathic pulmonary arterial hypertension (IPAH). These mechanisms can modulate expression of extracellular superoxide dismutase (SOD3 or EC-SOD), a key vascular antioxidant enzyme, and loss of vascular SOD3 worsens outcomes in animal models of pulmonary arterial hypertension. We hypothesized that SOD3 gene expression is decreased in patients with IPAH due to aberrant DNA methylation and/or histone deacetylation. We used lung tissue and pulmonary artery smooth muscle cells (PASMC) from subjects with IPAH at transplantation and from failed donors (FD). Lung SOD3 mRNA expression and activity was decreased in IPAH vs. FD. In contrast, mitochondrial SOD (Mn-SOD or SOD2) protein expression was unchanged and intracellular SOD activity was unchanged. Using bisulfite sequencing in genomic lung or PASMC DNA, we found the methylation status of the SOD3 promoter was similar between FD and IPAH. Furthermore, treatment with 5-aza-2′-deoxycytidine did not increase PASMC SOD3 mRNA, suggesting DNA methylation was not responsible for PASMC SOD3 expression. Though total histone deacetylase (HDAC) activity, histone acetyltransferase (HAT) activity, acetylated histones, and acetylated SP1 were similar between IPAH and FD, treatment with two selective class I HDAC inhibitors increased SOD3 only in IPAH PASMC. Class I HDAC3 siRNA also increased SOD3 expression. Trichostatin A, a pan-HDAC inhibitor, decreased proliferation in IPAH, but not in FD PASMC. These data indicate that histone deacetylation, specifically via class I HDAC3, decreases SOD3 expression in PASMC and HDAC inhibitors may protect IPAH in part by increasing PASMC SOD3 expression. PMID:27233998

Passive Smoking Impairs Histone Deacetylase-2 in Children With Severe Asthma

PubMed Central

Kobayashi, Yoshiki; Bossley, Cara; Gupta, Atul; Akashi, Kenichi; Tsartsali, Lemonia; Mercado, Nicolas; Barnes, Peter J.; Bush, Andrew

2014-01-01

Background: Parental smoking is known to worsen asthma symptoms in children and to make them refractory to asthma treatment, but the molecular mechanism is unclear. Oxidative stress from tobacco smoke has been reported to impair histone deacetylase-2 (HDAC2) via phosphoinositide-3-kinase (PI3K)/Akt activation and, thus, to reduce corticosteroid sensitivity. The aim of this study was to investigate passive smoking-dependent molecular abnormalities in alveolar macrophages (AMs) by comparing passive smoke-exposed children and non-passive smoke-exposed children with uncontrolled severe asthma. Methods: BAL fluid (BALF) was obtained from 19 children with uncontrolled severe asthma (10 non-passive smoking-exposed subjects and nine passive smoking-exposed subjects), and HDAC2 expression/activity, Akt/HDAC2 phosphorylation levels, and corticosteroid responsiveness in AMs were evaluated. Results: Parental smoking reduced HDAC2 protein expression by 54% and activity by 47%, with concomitant enhancement of phosphorylation of Akt1 and HDAC2. In addition, phosphorylation levels of Akt1 correlated positively with HDAC2 phosphorylation levels and negatively with HDAC2 activity. Furthermore, passive smoke exposure reduced the inhibitory effects of dexamethasone on tumor necrosis factor-α-induced CXCL8 release in AMs. There were relatively higher neutrophil counts and CXCL8 concentrations in BALF and lower Asthma Control Test scores compared with non-passive smoke-exposed children with uncontrolled severe asthma. Conclusions: Passive smoking impairs HDAC2 function via PI3K signaling activation, which could contribute to corticosteroid-insensitive inflammation in children with severe asthma. This novel mechanism will be a treatment target in children with severe asthma and stresses the need for a smoke-free environment for asthmatic children. PMID:24030221

The role of class I histone deacetylase (HDAC) on gluconeogenesis in liver

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oiso, Hiroshi; Furukawa, Noboru, E-mail: n-furu@gpo.kumamoto-u.ac.jp; Suefuji, Mihoshi

2011-01-07

Research highlights: {yields} A novel class I HDAC inhibitor decreased hepatic PEPCK mRNA and gluconeogenesis. {yields} Inhibition of HDAC decreased PEPCK by reducing HNF4{alpha} expression and FoxO1 activity. {yields} siRNA knockdown of HDAC1 in HepG2 cells reduced the expression of PEPCK and HNF4{alpha}. {yields} Inhibition of class I HDAC improves glucose homeostasis in HFD mice. -- Abstract: Hepatic gluconeogenesis is crucial for glucose homeostasis. Although sirtuin 1 (Sirt1) is implicated in the regulation of gluconeogenesis in the liver, the effects of other histone deacetylases (HDAC) on gluconeogenesis are unclear. The aim of this study was to identify the role ofmore » class I HDACs in hepatic gluconeogenesis. In HepG2 cells and the liver of mice, the expressions of phosphoenol pyruvate carboxykinase (PEPCK) and hepatocyte nuclear factor 4{alpha} (HNF4{alpha}) were significantly decreased by treatment with a newly designed class I HDAC inhibitor, Ky-2. SiRNA knockdown of HDAC1 expression, but not of HDAC2 or HDAC3, in HepG2 cells decreased PEPCK and HNF4{alpha} expression. In HepG2 cells, insulin-stimulated phosphorylation of Akt and forkhead box O 1 (FoxO1) was increased by Ky-2. Pyruvate tolerance tests in Ky-2-treated high-fat-diet (HFD)-fed mice showed a marked reduction in blood glucose compared with vehicle-treated HFD mice. These data suggest that class I HDACs increase HNF4{alpha} protein expression and the transcriptional activity of FoxO1, followed by the induction of PEPCK mRNA expression and gluconeogenesis in liver.« less

Histone Deacetylase Rpd3 Regulates Olfactory Projection Neuron Dendrite Targeting via the Transcription Factor Prospero

PubMed Central

Tea, Joy S.; Chihara, Takahiro; Luo, Liqun

2010-01-01

Compared to the mechanisms of axon guidance, relatively little is known about the transcriptional control of dendrite guidance. The Drosophila olfactory system with its stereotyped organization provides an excellent model to study the transcriptional control of dendrite wiring specificity. Each projection neuron (PN) targets its dendrites to a specific glomerulus in the antennal lobe and its axon stereotypically to higher brain centers. Using a forward genetic screen, we identified a mutation in Rpd3 that disrupts PN targeting specificity. Rpd3 encodes a class I histone deacetylase (HDAC) homologous to mammalian HDAC1 and HDAC2. Rpd3−/− PN dendrites that normally target to a dorsolateral glomerulus mistarget to medial glomeruli in the antennal lobe, and axons exhibit a severe overbranching phenotype. These phenotypes can be rescued by postmitotic expression of Rpd3 but not HDAC3, the only other class I HDAC in Drosophila. Furthermore, disruption of the atypical homeodomain transcription factor Prospero (Pros) yields similar phenotypes, which can be rescued by Pros expression in postmitotic neurons. Strikingly, overexpression of Pros can suppress Rpd3−/− phenotypes. Our study suggests a specific function for the general chromatin remodeling factor Rpd3 in regulating dendrite targeting in neurons, largely through the postmitotic action of the Pros transcription factor. PMID:20660276

Murine craniofacial development requires Hdac3-mediated repression of Msx gene expression.

PubMed

Singh, Nikhil; Gupta, Mudit; Trivedi, Chinmay M; Singh, Manvendra K; Li, Li; Epstein, Jonathan A

2013-05-15

Craniofacial development is characterized by reciprocal interactions between neural crest cells and neighboring cell populations of ectodermal, endodermal and mesodermal origin. Various genetic pathways play critical roles in coordinating the development of cranial structures by modulating the growth, survival and differentiation of neural crest cells. However, the regulation of these pathways, particularly at the epigenomic level, remains poorly understood. Using murine genetics, we show that neural crest cells exhibit a requirement for the class I histone deacetylase Hdac3 during craniofacial development. Mice in which Hdac3 has been conditionally deleted in neural crest demonstrate fully penetrant craniofacial abnormalities, including microcephaly, cleft secondary palate and dental hypoplasia. Consistent with these abnormalities, we observe dysregulation of cell cycle genes and increased apoptosis in neural crest structures in mutant embryos. Known regulators of cell cycle progression and apoptosis in neural crest, including Msx1, Msx2 and Bmp4, are upregulated in Hdac3-deficient cranial mesenchyme. These results suggest that Hdac3 serves as a critical regulator of craniofacial morphogenesis, in part by repressing core apoptotic pathways in cranial neural crest cells. Copyright © 2013 Elsevier Inc. All rights reserved.

The Antiparasitic Clioquinol Induces Apoptosis in Leukemia and Myeloma Cells by Inhibiting Histone Deacetylase Activity*

PubMed Central

Cao, Biyin; Li, Jie; Zhu, Jingyu; Shen, Mingyun; Han, Kunkun; Zhang, Zubin; Yu, Yang; Wang, Yali; Wu, Depei; Chen, Suning; Sun, Aining; Tang, Xiaowen; Zhao, Yun; Qiao, Chunhua; Hou, Tingjun; Mao, Xinliang

2013-01-01

The antiparasitic clioquinol (CQ) represents a class of novel anticancer drugs by interfering with proteasome activity. In the present study, we found that CQ induced blood cancer cell apoptosis by inhibiting histone deacetylases (HDACs). CQ accumulated the acetylation levels of several key proteins including histone H3 (H3), p53, HSP90, and α-tubulin. In the mechanistic study, CQ was found to down-regulate HDAC1, -3, -4, and -5 in both myeloma and leukemia cells. Computer modeling analysis revealed that CQ was well docked into the active pocket of the enzyme, where the oxygen and nitrogen atoms in CQ formed stable coordinate bonds with the zinc ion, and the hydroxyl group from CQ formed an effective hydrogen bond with Asp-267. Moreover, co-treatment with CQ and zinc/copper chloride led to decreased Ac-H3. Furthermore, CQ inhibited the activity of Class I and IIa HDACs in the cell-free assays, demonstrating that CQ interfered with HDAC activity. By inhibiting HDAC activity, CQ induced expression of p21, p27, and p53, cell cycle arrest at G1 phase, and cell apoptosis. This study suggested that the HDAC enzymes are targets of CQ, which provided a novel insight into the molecular mechanism of CQ in the treatment of hematological malignancies. PMID:24114842

Transcriptional co-repressor SIN3A silencing rescues decline in memory consolidation during scopolamine-induced amnesia.

PubMed

Srivas, Sweta; Thakur, Mahendra K

2018-05-01

Epigenetic modifications through methylation of DNA and acetylation of histones modulate neuronal gene expression and regulate long-term memory. Earlier we demonstrated that scopolamine-induced decrease in memory consolidation is correlated with enhanced expression of hippocampal DNA methyltransferase 1 (DNMT1) and histone deacetylase 2 (HDAC2) in mice. DNMT1 and HDAC2 act together by recruiting a co-repressor complex and deacetylating the chromatin. The catalytic activity of HDACs is mainly dependent on its incorporation into multiprotein co-repressor complexes, among which SIN3A-HDAC2 co-repressor is widely studied to regulate synaptic plasticity. However, the involvement of co-repressor complex in regulating memory loss or amnesia is unexplored. This study examines the role of co-repressor SIN3A in scopolamine-induced amnesia through epigenetic changes in the hippocampus. Scopolamine treatment remarkably enhanced hippocampal SIN3A expression in mice. To prevent such increase in SIN3A expression, we used hippocampal infusion of SIN3A-siRNA and assessed the effect of SIN3A silencing on scopolamine-induced amnesia. Silencing of SIN3A in amnesic mice reduced the binding of HDAC2 at neuronal immediate early genes (IEGs) promoter, but did not change the expression of HDAC2. Furthermore, it increased acetylation of H3K9 and H3K14 at neuronal IEGs (Arc, Egr1, Homer1 and Narp) promoter, prevented scopolamine-induced down-regulation of IEGs and improved consolidation of memory during novel object recognition task. These findings together suggest that SIN3A has a critical role in regulation of synaptic plasticity and might act as a potential therapeutic target to rescue memory decline during amnesia and other neuropsychiatric pathologies. © 2018 International Society for Neurochemistry.

Blocking the association of HDAC4 with MAP1S accelerates autophagy clearance of mutant Huntingtin

PubMed Central

Yue, Fei; Li, Wenjiao; Zou, Jing; Chen, Qi; Xu, Guibin; Huang, Hai; Xu, Zhen; Zhang, Sheng; Gallinari, Paola; Wang, Fen; McKeehan, Wallace L.; Liu, Leyuan

2015-01-01

Autophagy controls and executes the turnover of abnormally aggregated proteins. MAP1S interacts with the autophagy marker LC3 and positively regulates autophagy flux. HDAC4 associates with the aggregation-prone mutant huntingtin protein (mHTT) that causes Huntington's disease, and colocalizes with it in cytosolic inclusions. It was suggested HDAC4 interacts with MAP1S in a yeast two-hybrid screening. Here, we found that MAP1S interacts with HDAC4 via a HDAC4-binding domain (HBD). HDAC4 destabilizes MAP1S, suppresses autophagy flux and promotes the accumulation of mHTT aggregates. This occurs by an increase in the deacetylation of the acetylated MAP1S. Either suppression of HDAC4 with siRNA or overexpression of the MAP1S HBD leads to stabilization of MAP1S, activation of autophagy flux and clearance of mHTT aggregates. Therefore, specific interruption of the HDAC4-MAP1S interaction with short peptides or small molecules to enhance autophagy flux may relieve the toxicity of mHTT associated with Huntington's disease and improve symptoms of HD patients. PMID:26540094

Quinazolin-4-one derivatives as selective histone deacetylase-6 inhibitors for the treatment of Alzheimer's disease.

PubMed

Yu, Chao-Wu; Chang, Pei-Teh; Hsin, Ling-Wei; Chern, Ji-Wang

2013-09-12

Novel quinazolin-4-one derivatives containing a hydroxamic acid moiety were designed and synthesized. All compounds were subjected to histone deacetylase (HDAC) enzymatic assays to identify selective HDAC6 inhibitors with nanomolar IC50 values. (E)-3-(2-Ethyl-7-fluoro-4-oxo-3-phenethyl-3,4-dihydroquinazolin-6-yl)-N-hydroxyacrylamide, 4b, is the most potent HDAC6 inhibitor (IC50, 8 nM). In vitro, these compounds induced neurite outgrowth accompanied by growth-associated protein 43 expression, and they enhanced the synaptic activities of PC12 and SH-SY5Y neuronal cells without producing toxic or mitogenic effects. Several of the compounds dramatically increased nonhistone protein acetylation, specifically of α-tubulin. Some of the more potent HDAC6 inhibitors decreased zinc-mediated β-amyloid aggregation in vitro. N-Hydroxy-3-(2-methyl-4-oxo-3-phenethyl-3,4-dihydro-quinazolin-7-yl)-acrylamide, 3f, the most promising drug candidate, selectively inhibits HDAC6 (IC50, 29 nM), practically does not affect human ether-a-go-go-related membrane channel activity (IC50 >10 μM) or cytochrome P450 activity (IC50 >6.5 μM) in vitro, and significantly improves learning-based performances of mice with β-amyloid-induced hippocampal lesions.

Histone Deacetylase 3 Is Necessary for Proper Brain Development*

PubMed Central

Norwood, Jordan; Franklin, Jade M.; Sharma, Dharmendra; D'Mello, Santosh R.

2014-01-01

The functional role of histone deacetylase 3 (HDAC3) in the developing brain has yet to be elucidated. We show that mice lacking HDAC3 in neurons and glia of the central nervous system, Nes-Cre/HDAC3 conditional KO mice, show major abnormalities in the cytoarchitecture of the neocortex and cerebellum and die within 24 h of birth. Later-born neurons do not localize properly in the cortex. A similar mislocalization is observed with cerebellar Purkinje neurons. Although the proportion of astrocytes is higher than normal, the numbers of oligodendrocytes are reduced. In contrast, conditional knockout of HDAC3 in neurons of the forebrain and certain other brain regions, using Thy1-Cre and calcium/calmodulin dependent protein kinase II α-Cre for ablation, produces no overt abnormalities in the organization of cells within the cortex or of cerebellar Purkinje neurons at birth. However, both lines of conditional knockout mice suffer from progressive hind limb paralysis and ataxia and die around 6 weeks after birth. The mice display an increase in overall numbers of cells, higher numbers of astrocytes, and Purkinje neuron degeneration. Taken together, our results demonstrate that HDAC3 plays an essential role in regulating brain development, with effects on both neurons and glia in different brain regions. PMID:25339172

EZH2 and histone deacetylase inhibitors induce apoptosis in triple negative breast cancer cells by differentially increasing H3 Lys27 acetylation in the BIM gene promoter and enhancers.

PubMed

Huang, Julia P; Ling, Kun

2017-11-01

Enhancer of zeste homolog 2 (EZH2), a subunit of polycomb repressive complex 2, is a histone methyl-transferase and is considered to work cooperatively with histone deacetylases (HDACs) in the same protein complex to mediate gene transcription repression by increasing histone H3 Lys 27 trimethylation (H3K27me3), in particular in the nucleosome (s). EZH2 is overexpressed in numerous types of cancer, including triple negative breast cancer (TNBC), a subtype of breast cancer, which there are no effective treatment options for. Thus, inhibition of EZH2 may be harnessed for targeted therapy of this disease. The present study demonstrated that co-treatment with an EZH2 inhibitor and a HDAC inhibitor additively induced apoptosis in two TNBC cell lines, namely MDA-MB-231 and MDA-MB-436. The increased rate of cell death was associated with an elevation of B cell lymphoma-2 like 11 (BIM) expression level, a pro-apoptotic protein at the protein and mRNA expression levels in these two cell lines. The expression of forkhead box O1 (FOXO1), a known upstream transcriptional activator of BIM , was upregulated in both cell lines by the HDAC inhibitor, and the effect was more pronounced in MDA-MB-436 cells with higher phosphorylation levels of protein kinase B, a negative regulator of FOXO1, compared with MDA-MB-231 cells. Conversely, FOXO1 expression was inhibited following treatment with the EZH2 inhibitor, suggesting that EZH2 and HDAC inhibitors induced BIM expression via a FOXO1-independent mechanism. The present study further revealed that the EZH2 inhibitor, but not the HDAC inhibitor, induced high levels of H3K27 acetylation (H3K27ac) in the BIM promoter. By contrast, compared with the effect of the EZH2 inhibitor, HDAC inhibitor treatment resulted in an increase in H3K27ac at two BIM enhancers. Collectively, the results of the present study indicated that EZH2 and HDACs act differentially on H3K27ac levels in the nucleosome at the promoter and enhancer regions of the BIM gene. Through the upregulation of BIM, co-treatment with EZH2 and HDAC inhibitors had a pronounced therapeutic effect on TNBC cells, suggesting that co-targeting EZH2 and HDAC proteins represents a viable therapeutic option for the treatment of TNBC.

Acute exercise and periodized training in different environments affect histone deacetylase activity and interleukin-10 levels in peripheral blood of patients with type 2 diabetes.

PubMed

Korb, Arthiese; Bertoldi, Karine; Agustini Lovatel, Gisele; Sudatti Dellevatti, Rodrigo; Rostirola Elsner, Viviane; Carolina Ferreira Meireles, Louisiana; Fernando Martins Kruel, Luiz; Rodrigues Siqueira, Ionara

2018-05-02

Our purpose was to investigate the effects of aerobic periodized training in aquatic and land environments on plasma histone deacetylase (HDAC) activity and cytokines levels in peripheral blood of diabetes mellitus type 2 (T2DM) patients. The patients underwent 12 weeks of periodized training programs that including walking or running in a swimming pool (aquatic group) or in a track (dry land group). Blood samples were collected immediately before and after both first and last sessions. Plasma cytokine levels and HDAC activity in peripheral blood mononuclear cell (PBMC) was measured. The exercise performed in both environments similarly modulated the evaluated acetylation mark, global HDAC activity. However, a differential profile depending on the evaluated moments was detected, since exercise increased acutely HDAC activity in sedentary and after 12 weeks of training period, while a reduced HDAC activity was observed following periodized training (samples collected before the last session). Additionally, the 12 weeks of periodized exercise in both environments increased IL-10 levels. Our data support the hypothesis that the modulation of HDAC activity and inflammatory status might be at least partially related to the effects of exercise effects on T2DM. The periodized training performed in both aquatic and land environments impacts similarly epigenetic and inflammatory status. Copyright © 2018 Elsevier B.V. All rights reserved.

Comparative molecular dynamics simulations of histone deacetylase-like protein: binding modes and free energy analysis to hydroxamic acid inhibitors.

PubMed

Yan, Chunli; Xiu, Zhilong; Li, Xiaohui; Li, Shenmin; Hao, Ce; Teng, Hu

2008-10-01

Histone deacetylases (HDACs) play an important role in gene transcription, and inhibitors of HDACs can induce cell differentiation and suppress cell proliferation in tumor cells. Histone deacetylase1 (HDAC1) binds suberanilohydroxamic acid (SAHA) and 7-phenyl-2, 4, 6-hepta-trienoyl hydroxamic acid (CG-1521) with moderately low affinity (DeltaG = -8.6 and -7.8 kcal mol(-1)). The structurally related (E)-2-(3-(3-(hydroxyamino)-3-oxoprop-1-enyl)phenyl)-N(1),N(3)-diphenylmalonamide (SK-683), a Trichostatin A (TSA)-like HDAC1 inhibitor, and TSA are bound to the HDAC1 with -12.3 and -10.3 kcal mol(-1) of DeltaG, higher binding free energies than SAHA and CG-1521. Histone deacetylase-like protein (HDLP), an HDAC homologue, shows a 35.2% sequence identity of HDLP and human HDAC1. Molecular dynamics simulation and the molecular mechanics/generalized-Born surface area (MM-GBSA) free energy calculations were applied to investigate the factors responsible for the relatively activity of these four inhibitors to HDLP. In addition, computational alanine scanning of the binding site residues was carried out to determine the contribution components from van der Waals, electrostatic interaction, nonpolar and polar energy of solvation as well as the effects of backbones and side-chains with the MM-GBSA method. MM-GBSA methods reproduced the experimental relative affinities of the four inhibitors in good agreement (R(2) = 0.996) between experimental and computed binding energies. The MM-GBSA calculations showed that, the number of hydrogen bonds formed between the HDLP and inhibitors, which varied in the system studied, and electrostatic interactions determined the magnitude of the free energies for HDLP-inhibitor interactions. The MM-GBSA calculations revealed that the binding of HDLP to these four hydroxamic acid inhibitors is mainly driven by van der Waals/nonpolar interactions. This study can be a guide for the optimization of HDAC inhibitors and future design of new therapeutic agents for the treatment of cancer.

A microenvironment-mediated c-Myc/miR-548m/HDAC6 amplification loop in non-Hodgkin B cell lymphomas

PubMed Central

Lwin, Tint; Zhao, Xiaohong; Cheng, Fengdong; Zhang, Xinwei; Huang, Andy; Shah, Bijal; Zhang, Yizhuo; Moscinski, Lynn C.; Choi, Yong Sung; Kozikowski, Alan P.; Bradner, James E.; Dalton, William S.; Sotomayor, Eduardo; Tao, Jianguo

2013-01-01

A dynamic interaction occurs between the lymphoma cell and its microenvironment, with each profoundly influencing the behavior of the other. Here, using a clonogenic coculture growth system and a xenograft mouse model, we demonstrated that adhesion of mantle cell lymphoma (MCL) and other non-Hodgkin lymphoma cells to lymphoma stromal cells confers drug resistance, clonogenicity, and induction of histone deacetylase 6 (HDAC6). Furthermore, stroma triggered a c-Myc/miR-548m feed-forward loop, linking sustained c-Myc activation, miR-548m downregulation, and subsequent HDAC6 upregulation and stroma-mediated cell survival and lymphoma progression in lymphoma cell lines, primary MCL and other B cell lymphoma cell lines. Treatment with an HDAC6-selective inhibitor alone or in synergy with a c-Myc inhibitor enhanced cell death, abolished cell adhesion–mediated drug resistance, and suppressed clonogenicity and lymphoma growth ex vivo and in vivo. Together, these data suggest that the lymphoma-stroma interaction in the lymphoma microenvironment directly impacts the biology of lymphoma through genetic and epigenetic regulation, with HDAC6 and c-Myc as potential therapeutic targets. PMID:24216476

The proto-oncoprotein FBI-1 interacts with MBD3 to recruit the Mi-2/NuRD-HDAC complex and BCoR and to silence p21WAF/CDKN1A by DNA methylation.

PubMed

Choi, Won-Il; Jeon, Bu-Nam; Yoon, Jae-Hyeon; Koh, Dong-In; Kim, Myung-Hwa; Yu, Mi-Young; Lee, Kyung-Mi; Kim, Youngsoo; Kim, Kyunggon; Hur, Sujin Susanne; Lee, Choong-Eun; Kim, Kyung-Sup; Hur, Man-Wook

2013-07-01

The tumour-suppressor gene CDKN1A (encoding p21Waf/Cip1) is thought to be epigenetically repressed in cancer cells. FBI-1 (ZBTB7A) is a proto-oncogenic transcription factor repressing the alternative reading frame and p21WAF/CDKN1A genes of the p53 pathway. FBI-1 interacts directly with MBD3 (methyl-CpG-binding domain protein 3) in the nucleus. We demonstrated that FBI-1 binds both non-methylated and methylated DNA and that MBD3 is recruited to the CDKN1A promoter through its interaction with FBI-1, where it enhances transcriptional repression by FBI-1. FBI-1 also interacts with the co-repressors nuclear receptor corepressor (NCoR), silencing mediator for retinoid and thyroid receptors (SMRT) and BCL-6 corepressor (BCoR) to repress transcription. MBD3 regulates a molecular interaction between the co-repressor and FBI-1. MBD3 decreases the interaction between FBI-1 and NCoR/SMRT but increases the interaction between FBI-1 and BCoR. Because MBD3 is a subunit of the Mi-2 autoantigen (Mi-2)/nucleosome remodelling and histone deacetylase (NuRD)-HDAC complex, FBI-1 recruits the Mi-2/NuRD-HDAC complex via MBD3. BCoR interacts with the Mi-2/NuRD-HDAC complex, DNMTs and HP1. MBD3 and BCoR play a significant role in the recruitment of the Mi-2/NuRD-HDAC complex- and the NuRD complex-associated proteins, DNMTs and HP. By recruiting DNMTs and HP1, Mi-2/NuRD-HDAC complex appears to play key roles in epigenetic repression of CDKN1A by DNA methylation.

Intranasal siRNA administration reveals IGF2 deficiency contributes to impaired cognition in Fragile X syndrome mice

PubMed Central

Pardo, Marta; Cheng, Yuyan; Velmeshev, Dmitry; Magistri, Marco; Martinez, Ana; Faghihi, Mohammad A.; Jope, Richard S.; Beurel, Eleonore

2017-01-01

Molecular mechanisms underlying learning and memory remain imprecisely understood, and restorative interventions are lacking. We report that intranasal administration of siRNAs can be used to identify targets important in cognitive processes and to improve genetically impaired learning and memory. In mice modeling the intellectual deficiency of Fragile X syndrome, intranasally administered siRNA targeting glycogen synthase kinase-3β (GSK3β), histone deacetylase-1 (HDAC1), HDAC2, or HDAC3 diminished cognitive impairments. In WT mice, intranasally administered brain-derived neurotrophic factor (BDNF) siRNA or HDAC4 siRNA impaired learning and memory, which was partially due to reduced insulin-like growth factor-2 (IGF2) levels because the BDNF siRNA– or HDAC4 siRNA–induced cognitive impairments were ameliorated by intranasal IGF2 administration. In Fmr1–/– mice, hippocampal IGF2 was deficient, and learning and memory impairments were ameliorated by IGF2 intranasal administration. Therefore intranasal siRNA administration is an effective means to identify mechanisms regulating cognition and to modulate therapeutic targets. PMID:28352664

Intranasal siRNA administration reveals IGF2 deficiency contributes to impaired cognition in Fragile X syndrome mice.

PubMed

Pardo, Marta; Cheng, Yuyan; Velmeshev, Dmitry; Magistri, Marco; Eldar-Finkelman, Hagit; Martinez, Ana; Faghihi, Mohammad A; Jope, Richard S; Beurel, Eleonore

2017-03-23

Molecular mechanisms underlying learning and memory remain imprecisely understood, and restorative interventions are lacking. We report that intranasal administration of siRNAs can be used to identify targets important in cognitive processes and to improve genetically impaired learning and memory. In mice modeling the intellectual deficiency of Fragile X syndrome, intranasally administered siRNA targeting glycogen synthase kinase-3β (GSK3β), histone deacetylase-1 (HDAC1), HDAC2, or HDAC3 diminished cognitive impairments. In WT mice, intranasally administered brain-derived neurotrophic factor (BDNF) siRNA or HDAC4 siRNA impaired learning and memory, which was partially due to reduced insulin-like growth factor-2 (IGF2) levels because the BDNF siRNA- or HDAC4 siRNA-induced cognitive impairments were ameliorated by intranasal IGF2 administration. In Fmr1 -/- mice, hippocampal IGF2 was deficient, and learning and memory impairments were ameliorated by IGF2 intranasal administration. Therefore intranasal siRNA administration is an effective means to identify mechanisms regulating cognition and to modulate therapeutic targets.

Histone deacetylase inhibitors restore IL-10 expression in lipopolysaccharide-induced cell inflammation and reduce IL-1β and IL-6 production in breast silicone implant in C57BL/6J wild-type murine model.

PubMed

Di Liddo, Rosa; Valente, Sergio; Taurone, Samanta; Zwergel, Clemens; Marrocco, Biagina; Turchetta, Rosaria; Conconi, Maria Teresa; Scarpa, Carlotta; Bertalot, Thomas; Schrenk, Sandra; Mai, Antonello; Artico, Marco

2016-01-20

Among epigenetic enzymes, histone deacetylases (HDACs) are responsible for regulating the expression of an extensive array of genes by reversible deacetylation of nuclear histones as well as a large number of non-histone proteins. Initially proposed for cancer therapy, recently the interest for HDAC inhibitors (HDACi) as orally active, safe, and anti-inflammatory agents is rising due to their ability in reducing the severity of inflammatory and autoimmune diseases. In particular, selective HDAC3, HDAC6, and HDAC8 inhibitors have been described to downregulate the expression of pro-inflammatory cytokines (TNF-α, TGF-β, IL-1β, and IL-6). Herein, using KB31, C2C12, and 3T3-J2 cell lines, we demonstrated that, under lipopolysaccharide-induced in vitro inflammation, HDAC3/6/8 inhibitor MC2625 and HDAC6-selective inhibitor MC2780 were effective at a concentration of 30 ng/mL to downregulate mRNA expression of pro-inflammatory cytokines (IL-1β and IL-6) and to promote the transcription of IL-10 gene, without affecting the cell viability. Afterwards, we investigated by immunohistochemistry the activity of MC2625 and MC2780 at a concentration of 60 ng/kg animal weight to regulate silicone-triggered immune response in C57BL/6J female mice. Our findings evidenced the ability of such inhibitors to reduce host inflammation in silicone implants promoting a thickness reduction of peri-implant fibrous capsule, upregulating IL-10 expression, and reducing the production of both IL-1β and IL-6. These results underline the potential application of MC2625 and MC2780 in inflammation-related diseases.

Imprinting regulator DNMT3L is a transcriptional repressor associated with histone deacetylase activity.

PubMed

Aapola, Ulla; Liiv, Ingrid; Peterson, Pärt

2002-08-15

DNMT3L is a regulator of imprint establishment of normally methylated maternal genomic sequences. DNMT3L shows high similarity to the de novo DNA methyltransferases, DNMT3A and DNMT3B, however, the amino acid residues needed for DNA cytosine methyltransferase activity have been lost from the DNMT3L protein sequence. Apart from methyltransferase activity, Dnmt3a and Dnmt3b serve as transcriptional repressors associating with histone deacetylase (HDAC) activity. Here we show that DNMT3L can also repress transcription by binding directly to HDAC1 protein. We have identified the PHD-like zinc finger of the ATRX domain as a main repression motif of DNMT3L, through which DNMT3L recruits the HDAC activity needed for transcriptional silencing. Furthermore, we show that DNMT3L protein contains an active nuclear localisation signal at amino acids 156-159. These results describe DNMT3L as a co-repressor protein and suggest that a transcriptionally repressed chromatin organisation through HDAC activity is needed for establishment of genomic imprints.

Class I Histone Deacetylase HDAC1 and WRN RECQ Helicase Contribute Additively to Protect Replication Forks upon Hydroxyurea-induced Arrest.

PubMed

Kehrli, Keffy; Phelps, Michael; Lazarchuk, Pavlo; Chen, Eleanor; Monnat, Ray; Sidorova, Julia M

2016-11-18

The WRN helicase/exonuclease is mutated in Werner syndrome of genomic instability and premature aging. WRN-depleted fibroblasts, although remaining largely viable, have a reduced capacity to maintain replication forks active during a transient hydroxyurea-induced arrest. A strand exchange protein, RAD51, is also required for replication fork maintenance, and here we show that recruitment of RAD51 to stalled forks is reduced in the absence of WRN. We performed a siRNA screen for genes that are required for viability of WRN-depleted cells after hydroxyurea treatment, and identified HDAC1, a member of the class I histone deacetylase family. One of the functions of HDAC1, which it performs together with a close homolog HDAC2, is deacetylation of new histone H4 deposited at replication forks. We show that HDAC1 depletion exacerbates defects in fork reactivation and progression after hydroxyurea treatment observed in WRN- or RAD51-deficient cells. The additive WRN, HDAC1 loss-of-function phenotype is also observed with a catalytic mutant of HDAC1; however, it does not correlate with changes in histone H4 deacetylation at replication forks. On the other hand, inhibition of histone deacetylation by an inhibitor specific to HDACs 1-3, CI-994, correlates with increased processing of newly synthesized DNA strands in hydroxyurea-stalled forks. WRN co-precipitates with HDAC1 and HDAC2. Taken together, our findings indicate that WRN interacts with HDACs 1 and 2 to facilitate activity of stalled replication forks under conditions of replication stress. © 2016 by The American Society for Biochemistry and Molecular Biology, Inc.

Ski co-repressor complexes maintain the basal repressed state of the TGF-beta target gene, SMAD7, via HDAC3 and PRMT5.

PubMed

Tabata, Takanori; Kokura, Kenji; Ten Dijke, Peter; Ishii, Shunsuke

2009-01-01

The products encoded by ski and its related gene, sno, (Ski and Sno) act as transcriptional co-repressors and interact with other co-repressors such as N-CoR/SMRT and mSin3A. Ski and Sno mediate transcriptional repression by various repressors, including Mad, Rb and Gli3. Ski/Sno also suppress transcription induced by multiple activators, such as Smads and c-Myb. In particular, the inhibition of TGF-beta-induced transcription by binding to Smads is correlated with the oncogenic activity of Ski and Sno. However, the molecular mechanism by which Ski and Sno mediate transcriptional repression remains unknown. In this study, we report the purification and characterization of Ski complexes. The Ski complexes purified from HeLa cells contained histone deacetylase 3 (HDAC3) and protein arginine methyltransferase 5 (PRMT5), in addition to multiple Smad proteins (Smad2, Smad3 and Smad4). Chromatin immunoprecipitation assays indicated that these components of the Ski complexes were localized on the SMAD7 gene promoter, which is the TGF-beta target gene, in TGF-beta-untreated HepG2 cells. Knockdown of these components using siRNA led to up-regulation of SMAD7 mRNA. These results indicate that Ski complexes serve to maintain a TGF-beta-responsive promoter at a repressed basal level via the activities of histone deacetylase and histone arginine methyltransferase.

Regulation of Cardiac Stress Signaling by Protein Kinase D1

PubMed Central

Harrison, Brooke C.; Kim, Mi-Sung; van Rooij, Eva; Plato, Craig F.; Papst, Philip J.; Vega, Rick B.; McAnally, John A.; Richardson, James A.; Bassel-Duby, Rhonda; Olson, Eric N.; McKinsey, Timothy A.

2006-01-01

In response to pathological stresses such as hypertension or myocardial infarction, the heart undergoes a remodeling process that is associated with myocyte hypertrophy, myocyte death, and fibrosis. Histone deacetylase 5 (HDAC5) is a transcriptional repressor of cardiac remodeling that is subject to phosphorylation-dependent neutralization in response to stress signaling. Recent studies have suggested a role for protein kinase C (PKC) and its downstream effector, protein kinase D1 (PKD1), in the control of HDAC5 phosphorylation. While PKCs are well-documented regulators of cardiac signaling, the function of PKD1 in heart muscle remains unclear. Here, we demonstrate that PKD1 catalytic activity is stimulated in cardiac myocytes by diverse hypertrophic agonists that signal through G protein-coupled receptors (GPCRs) and Rho GTPases. PKD1 activation in cardiomyocytes occurs through PKC-dependent and -independent mechanisms. In vivo, cardiac PKD1 is activated in multiple rodent models of pathological cardiac remodeling. PKD1 activation correlates with phosphorylation-dependent nuclear export of HDAC5, and reduction of endogenous PKD1 expression with small interfering RNA suppresses HDAC5 shuttling and associated cardiomyocyte growth. Conversely, ectopic overexpression of constitutively active PKD1 in mouse heart leads to dilated cardiomyopathy. These findings support a role for PKD1 in the control of pathological remodeling of the heart via its ability to phosphorylate and neutralize HDAC5. PMID:16648482

HDAC8 overexpression in mesenchymal stromal cells from JAK2+ myeloproliferative neoplasms: a new therapeutic target?

PubMed Central

Ramos, Teresa L.; Sánchez-Abarca, Luis Ignacio; Redondo, Alba; Hernández-Hernández, Ángel; Almeida, Antonio M.; Puig, Noemí; Rodríguez, Concepción; Ortega, Rebeca; Preciado, Silvia; Rico, Ana; Muntión, Sandra; González Porras, José Ramón; Cañizo, Consuelo Del; Sánchez-Guijo, Fermín

2017-01-01

Histone deacetylases (HDACs) are involved in epigenetic modulation and their aberrant expression has been demonstrated in myeloproliferative neoplasms (MPN). HDAC8 inhibition has been shown to inhibit JAK2/STAT5 signaling in hematopoietic cells from MPN. Nevertheless, the role of HDAC8 expression in bone marrow-mesenchymal stromal cells (BM-MSC) has not been assessed. In the current work we describe that HDAC8 is significantly over-expressed in MSC from in JAK-2 positive MPN compared to those from healthy-donors (HD-MSC). Using a selective HDAC8 inhibitor (PCI34051), we verified that the subsequent decrease in the protein and mRNA expression of HDAC8 is linked with an increased apoptosis of malignant MSC whereas it has no effects on normal MSC. In addition, HDAC8 inhibition in MPN-MSC also decreased their capacity to maintain neoplastic hematopoiesis, by increasing the apoptosis, cell-cycle arrest and colony formation of JAK2+-hematopoietic cells. Mechanistic studies using different MPN cell lines revealed that PCI34051 induced their apoptosis, which is enhanced when were co-cultured with JAK2V617F-MSC, decreased their colony formation and the phosphorylation of STAT3 and STAT5. In summary, we show for the first time that the inhibition of HDAC8 in MSC from JAK2+ MPN patients selectively decreases their hematopoietic-supporting ability, suggesting that HDAC8 may be a potential therapeutic target in this setting by acting not only on hematopoietic cells but also on the malignant microenvironment. PMID:28390197

Genetic dissection of histone deacetylase requirement in tumor cells

PubMed Central

Haberland, Michael; Johnson, Aaron; Mokalled, Mayssa H.; Montgomery, Rusty L.; Olson, Eric N.

2009-01-01

Histone deacetylase inhibitors (HDACi) represent a new group of drugs currently being tested in a wide variety of clinical applications. They are especially effective in preclinical models of cancer where they show antiproliferative action in many different types of cancer cells. Recently, the first HDACi was approved for the treatment of cutaneous T cell lymphomas. Most HDACi currently in clinical development act by unspecifically interfering with the enzymatic activity of all class I HDACs (HDAC1, 2, 3, and 8), and it is widely believed that the development of isoform-specific HDACi could lead to better therapeutic efficacy. The contribution of the individual class I HDACs to different disease states, however, has so far not been fully elucidated. Here, we use a genetic approach to dissect the involvement of the different class I HDACs in tumor cells. We show that deletion of a single HDAC is not sufficient to induce cell death, but that HDAC1 and 2 play redundant and essential roles in tumor cell survival. Their deletion leads to nuclear bridging, nuclear fragmentation, and mitotic catastrophe, mirroring the effects of HDACi on cancer cells. These findings suggest that pharmacological inhibition of HDAC1 and 2 may be sufficient for anticancer activity, providing an experimental framework for the development of isoform-specific HDAC inhibitors. PMID:19416910

HDAC Inhibitors Target Replication Forks to Take a Stab at Cancer | Center for Cancer Research

Cancer.gov

The stability and function of many proteins within the cell can be altered with the addition or removal of certain chemical groups, including acetyl groups. Therefore, the enzymes that regulate these modifications have an important impact on the cell. One class of such enzymes—histone deacetylases, or HDACs—has been implicated in cancer and has become a target for cancer therapy. One HDAC inhibitor, called SAHA, has been approved for use against cutaneous T-cell lymphoma, and more than 60 ongoing clinical trials are continuing to test this class of drugs in various forms of cancer. However, the mechanisms by which SAHA and other HDAC inhibitors undermine the viability of tumor cells are not completely understood.

The N-CoR complex enables chromatin remodeler SNF2H to enhance repression by thyroid hormone receptor

PubMed Central

Alenghat, Theresa; Yu, Jiujiu; Lazar, Mitchell A

2006-01-01

Unliganded thyroid hormone receptor (TR) actively represses transcription via the nuclear receptor corepressor (N-CoR)/histone deacetylase 3 (HDAC3) complex. Although transcriptional activation by liganded receptors involves chromatin remodeling, the role of ATP-dependent remodeling in receptor-mediated repression is unknown. Here we report that SNF2H, the mammalian ISWI chromatin remodeling ATPase, is critical for repression of a genomically integrated, TR-regulated reporter gene. N-CoR and HDAC3 are both required for recruitment of SNF2H to the repressed gene. SNF2H does not interact directly with the N-CoR/HDAC3 complex, but binds to unacetylated histone H4 tails, suggesting that deacetylase activity of the corepressor complex is critical to SNF2H function. Indeed, HDAC3 as well as SNF2H are required for nucleosomal organization on the TR target gene. Consistent with these findings, reduction of SNF2H induces expression of an endogenous TR-regulated gene, dio1, in liver cells. Thus, although not apparent from studies of transiently transfected reporter genes, gene repression by TR involves the targeting of chromatin remodeling factors to repressed genes by the HDAC activity of nuclear receptor corepressors. PMID:16917504

Epigenetic modifications of triterpenoid ursolic acid in activating Nrf2 and blocking cellular transformation of mouse epidermal cells

PubMed Central

Kim, Hyuck; Ramirez, Christina N.; Su, Zheng-Yuan; Kong, Ah-Ng Tony

2016-01-01

Ursolic acid (UA), a well-known natural triterpenoid found in abundance in blueberries, cranberries and apple peels, has been reported to possess many beneficial health effects. These effects include anti-cancer activity in various cancers, such as skin cancer. Skin cancer is the most common cancer in the world. Nuclear factor E2-related factor 2 (Nrf2) is a master regulator of anti-oxidative stress response with anti-carcinogenic activity against UV- and chemical-induced tumor formation in the skin. Recent studies show that epigenetic modifications of Nrf2 play an important role in cancer prevention. However the epigenetic impact of UA on Nrf2 signaling remains poorly understood in skin cancer. In this study, we investigated the epigenetic effects of UA on mouse epidermal JB6 P+ cells. UA inhibited cellular transformation by 12-O-tetradecanoylphorbol-13-acetate (TPA) at a concentration at which the cytotoxicity was no more than 25%. Under this condition, UA induced the expression of the Nrf2-mediated detoxifying/antioxidant enzymes heme oxygenase-1 (HO-1), NAD(P)H:quinone oxidoreductase 1 (NQO1), and UDP-glucuronosyltransferase 1A1 (UGT1A1). DNA methylation analysis revealed that UA demethylated the first 15 CpG sites of the Nrf2 promoter region, which correlated with the re-expression of Nrf2. Furthermore, UA reduced the expression of epigenetic modifying enzymes, including the DNA methyltransferases (DNMTs) DNMT1 and DNMT3a and the histone deacetylases (HDACs) HDAC1, 2, 3, and 8 (Class I) and HDAC6 and 7 (Class II), and HDAC activity. Taken together, these results suggest that the epigenetic effects of the triterpenoid UA could potentially contribute to its beneficial effects, including the prevention of skin cancer. PMID:27260468

Synthesis and structure-activity relationship of histone deacetylase (HDAC) inhibitors with triazole-linked cap group.

PubMed

Chen, Po C; Patil, Vishal; Guerrant, William; Green, Patience; Oyelere, Adegboyega K

2008-05-01

Histone deacetylase (HDAC) inhibition is a recent, clinically validated therapeutic strategy for cancer treatment. Small molecule HDAC inhibitors identified so far fall in to three distinct structural motifs: the zinc-binding group (ZBG), a hydrophobic linker, and a recognition cap group. Here we report the suitability of a 1,2,3-triazole ring as a surface recognition cap group-linking moiety in suberoylanilide hydroxamic acid-like (SAHA-like) HDAC inhibitors. Using "click" chemistry (Huisgen cycloaddition reaction), several triazole-linked SAHA-like hydroxamates were synthesized. Structure-activity relationship revealed that the position of the triazole moiety as well as the identity of the cap group markedly affected the in vitro HDAC inhibition and cell growth inhibitory activities of this class of compounds.

Alpha-keto acid metabolites of organoselenium compounds inhibit histone deacetylase activity in human colon cancer cells.

PubMed

Nian, Hui; Bisson, William H; Dashwood, Wan-Mohaiza; Pinto, John T; Dashwood, Roderick H

2009-08-01

Methylselenocysteine (MSC) and selenomethionine (SM) are two organoselenium compounds receiving interest for their potential anticancer properties. These compounds can be converted to beta-methylselenopyruvate (MSP) and alpha-keto-gamma-methylselenobutyrate (KMSB), alpha-keto acid metabolites that share structural features with the histone deacetylase (HDAC) inhibitor butyrate. We tested the organoselenium compounds in an in vitro assay with human HDAC1 and HDAC8; whereas SM and MSC had little or no activity up to 2 mM, MSP and KMSB caused dose-dependent inhibition of HDAC activity. Subsequent experiments identified MSP as a competitive inhibitor of HDAC8, and computational modeling supported a mechanism involving reversible interaction with the active site zinc atom. In human colon cancer cells, acetylated histone H3 levels were increased during the period 0.5-48 h after treatment with MSP and KMSB, and there was dose-dependent inhibition of HDAC activity. The proportion of cells occupying G(2)/M of the cell cycle was increased at 10-50 microM MSP and KMSB, and apoptosis was induced, as evidenced by morphological changes, Annexin V staining and increased cleaved caspase-3, -6, -7, -9 and poly(adenosine diphosphate-ribose)polymerase. P21WAF1, a well-established target gene of clinically used HDAC inhibitors, was increased in MSP- and KMSB-treated colon cancer cells at both the messenger RNA and protein level, and there was enhanced P21WAF1 promoter activity. These studies confirm that in addition to targeting redox-sensitive signaling molecules, alpha-keto acid metabolites of organoselenium compounds alter HDAC activity and histone acetylation status in colon cancer cells, as recently observed in human prostate cancer cells.

Sodium Butyrate Protects -Against High Fat Diet-Induced Cardiac Dysfunction and Metabolic Disorders in Type II Diabetic Mice.

PubMed

Zhang, Ling; Du, Jianfeng; Yano, Naohiro; Wang, Hao; Zhao, Yu Tina; Dubielecka, Patrycja M; Zhuang, Shougang; Chin, Y Eugene; Qin, Gangjian; Zhao, Ting C

2017-08-01

Histone deacetylases are recently identified to act as key regulators for cardiac pathophysiology and metabolic disorders. However, the function of histone deacetylase (HDAC) in controlling cardiac performance in Type II diabetes and obesity remains unknown. Here, we determine whether HDAC inhibition attenuates high fat diet (HFD)-induced cardiac dysfunction and improves metabolic features. Adult mice were fed with either HFD or standard chow food for 24 weeks. Starting at 12 weeks, mice were divided into four groups randomly, in which sodium butyrate (1%), a potent HDAC inhibitor, was provided to chow and HFD-fed mice in drinking water, respectively. Glucose intolerance, metabolic parameters, cardiac function, and remodeling were assessed. Histological analysis and cellular signaling were examined at 24 weeks following euthanization of mice. HFD-fed mice demonstrated myocardial dysfunction and profound interstitial fibrosis, which were attenuated by HDAC inhibition. HFD-induced metabolic syndrome features insulin resistance, obesity, hyperinsulinemia, hyperglycemia, lipid accumulations, and cardiac hypertrophy, these effects were prevented by HDAC inhibition. Furthermore, HDAC inhibition attenuated myocyte apoptosis, reduced production of reactive oxygen species, and increased angiogenesis in the HFD-fed myocardium. Notably, HFD induced decreases in MKK3, p38, p38 regulated/activated protein kinase (PRAK), and Akt-1, but not p44/42 phosphorylation, which were prevented by HDAC inhibition. These results suggest that HDAC inhibition plays a critical role to preserve cardiac performance and mitigate metabolic disorders in obesity and diabetes, which is associated with MKK3/p38/PRAK pathway. The study holds promise in developing a new therapeutic strategy in the treatment of Type II diabetic-induced heart failure and metabolic disorders. J. Cell. Biochem. 118: 2395-2408, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Synthesis and biochemical analysis of 2,2,3,3,4,4,5,5,6,6,7,7-dodecafluoro-N-hydroxy-octanediamides as inhibitors of human histone deacetylases.

PubMed

Henkes, Leonhard M; Haus, Patricia; Jäger, Felix; Ludwig, Joachim; Meyer-Almes, Franz-Josef

2012-01-15

Inhibition of human histone deacetylases (HDACs) has emerged as a novel concept in the chemotherapeutic treatment of cancer. Two chemical entities, SAHA (ZOLINZA, Merck) and romidepsin (Istodax, Celgene) have been recently approved by the FDA as first-in-class drugs against cutaneous T-cell lymphoma. Clinical use of these drugs revealed several side effects including gastro-intestinal symptoms, fatigue, thrombocytopenia, thrombosis. Romidepsin is associated with an yet unresolved cardiotoxicity issue. A general hypothesis for the diminishment of unwanted adverse effects and an improved therapeutical window suggests the development of more isotype selective inhibitors. In this study the first time HDAC inhibitors with perfluorinated spacers between the zinc chelating moiety and the aromatic capping group were synthesized and tested against representatives of HDAC classes I, IIa and IIb. Competitive binding assays and a combined approach by using blind docking and molecular dynamics support binding of the perfluorinated analogs of SAHA to the active site of the HDAC-like amidohydrolase from Bordetella/Alcaligenes and presumably also to human HDACs. In contrast to the alkyl spacer of SAHA and derivatives, the perfluorinated alkyl spacer seems to contribute to or facilitate the induction of selectivity for class II, particularly class IIa, HDACs even though the overall potency of the perfluorinated SAHA analogs in this study against human HDACs remained still rather moderate in the micromolar range. Copyright © 2011 Elsevier Ltd. All rights reserved.

Ski Inhibits TGF-β/phospho-Smad3 Signaling and Accelerates Hypertrophic Differentiation in Chondrocytes

PubMed Central

Kim, Kyung-Ok; Sampson, Erik R.; Maynard, Robert D; O'Keefe, Regis J.; Chen, Di; Drissi, Hicham; Rosier, Randy N.; Hilton, Matthew J.; Zuscik, Michael J.

2012-01-01

Since TGF-β/Smad signaling inhibits chondrocyte maturation, endogenous negative regulators of TGF-β signaling are likely also important regulators of the chondrocyte differentiation process. One such negative regulator, Ski, is an oncoprotein that is known to inhibit TGF-β/Smad3 signaling via its interaction with phospho-Smad3 and recruitment of histone deacetylases (HDACs) to the DNA binding complex. Based on this, we hypothesized that Ski inhibits TGF-β signaling and accelerates maturation in chondrocytes via recruitment of HDACs to transcriptional complexes containing Smads. We tested this hypothesis in chick upper sternal chondrocytes (USCs), where gain and loss of Ski expression experiments were performed. Over-expression of Ski not only reversed the inhibitory effect of TGF-β on the expression of hypertrophic marker genes such as type × collagen (colX) and osteocalcin, it induced these genes basally as well. Conversely, knockdown of Ski by RNA interference led to a reduction of colX and osteocalcin expression under basal conditions. Furthermore, Ski blocked TGF-β induction of cyclinD1 and caused a basal up-regulation of Runx2, consistent with the observed acceleration of hypertrophy. Regarding mechanism, not only does Ski associate with phospho-Smad2 and 3, but its association with phospho-Smad3 is required for recruitment of HDAC4 and 5. Implicating this recruitment of HDACs in the phenotypic effects of Ski in chondrocytes, the HDAC inhibitor SAHA reversed the up-regulation of colX and osteocalcin in Ski over-expressing cells. These results suggest that inhibition of TGF-β signaling by Ski, which involves its association with phospho-Smad3 and recruitment of HDAC4 and 5, leads to accelerated chondrocyte differentiation. PMID:22461172

Nitric Oxide Modulates Histone Acetylation at Stress Genes by Inhibition of Histone Deacetylases.

PubMed

Mengel, Alexander; Ageeva, Alexandra; Georgii, Elisabeth; Bernhardt, Jörg; Wu, Keqiang; Durner, Jörg; Lindermayr, Christian

2017-02-01

Histone acetylation, which is an important mechanism to regulate gene expression, is controlled by the opposing action of histone acetyltransferases and histone deacetylases (HDACs). In animals, several HDACs are subjected to regulation by nitric oxide (NO); in plants, however, it is unknown whether NO affects histone acetylation. We found that treatment with the physiological NO donor S-nitrosoglutathione (GSNO) increased the abundance of several histone acetylation marks in Arabidopsis (Arabidopsis thaliana), which was strongly diminished in the presence of the NO scavenger 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. This increase was likely triggered by NO-dependent inhibition of HDAC activity, since GSNO and S-nitroso-N-acetyl-dl-penicillamine significantly and reversibly reduced total HDAC activity in vitro (in nuclear extracts) and in vivo (in protoplasts). Next, genome-wide H3K9/14ac profiles in Arabidopsis seedlings were generated by chromatin immunoprecipitation sequencing, and changes induced by GSNO, GSNO/2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide or trichostatin A (an HDAC inhibitor) were quantified, thereby identifying genes that display putative NO-regulated histone acetylation. Functional classification of these genes revealed that many of them are involved in the plant defense response and the abiotic stress response. Furthermore, salicylic acid, which is the major plant defense hormone against biotrophic pathogens, inhibited HDAC activity and increased histone acetylation by inducing endogenous NO production. These data suggest that NO affects histone acetylation by targeting and inhibiting HDAC complexes, resulting in the hyperacetylation of specific genes. This mechanism might operate in the plant stress response by facilitating the stress-induced transcription of genes. © 2017 American Society of Plant Biologists. All Rights Reserved.

Nitric Oxide Modulates Histone Acetylation at Stress Genes by Inhibition of Histone Deacetylases1[OPEN

PubMed Central

Mengel, Alexander; Ageeva, Alexandra; Durner, Jörg

2017-01-01

Histone acetylation, which is an important mechanism to regulate gene expression, is controlled by the opposing action of histone acetyltransferases and histone deacetylases (HDACs). In animals, several HDACs are subjected to regulation by nitric oxide (NO); in plants, however, it is unknown whether NO affects histone acetylation. We found that treatment with the physiological NO donor S-nitrosoglutathione (GSNO) increased the abundance of several histone acetylation marks in Arabidopsis (Arabidopsis thaliana), which was strongly diminished in the presence of the NO scavenger 2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide. This increase was likely triggered by NO-dependent inhibition of HDAC activity, since GSNO and S-nitroso-N-acetyl-dl-penicillamine significantly and reversibly reduced total HDAC activity in vitro (in nuclear extracts) and in vivo (in protoplasts). Next, genome-wide H3K9/14ac profiles in Arabidopsis seedlings were generated by chromatin immunoprecipitation sequencing, and changes induced by GSNO, GSNO/2-4-carboxyphenyl-4,4,5,5-tetramethylimidazoline-1-oxyl-3-oxide or trichostatin A (an HDAC inhibitor) were quantified, thereby identifying genes that display putative NO-regulated histone acetylation. Functional classification of these genes revealed that many of them are involved in the plant defense response and the abiotic stress response. Furthermore, salicylic acid, which is the major plant defense hormone against biotrophic pathogens, inhibited HDAC activity and increased histone acetylation by inducing endogenous NO production. These data suggest that NO affects histone acetylation by targeting and inhibiting HDAC complexes, resulting in the hyperacetylation of specific genes. This mechanism might operate in the plant stress response by facilitating the stress-induced transcription of genes. PMID:27980017

Inhibition of polyomavirus ori-dependent DNA replication by mSin3B.

PubMed

Xie, An-Yong; Folk, William R

2002-12-01

When tethered in cis to DNA, the transcriptional corepressor mSin3B inhibits polyomavirus (Py) ori-dependent DNA replication in vivo. Histone deacetylases (HDACs) appear not to be involved, since tethering class I and class II HDACs in cis does not inhibit replication and treating the cells with trichostatin A does not specifically relieve inhibition by mSin3B. However, the mSin3B L59P mutation that impairs mSin3B interaction with N-CoR/SMRT abrogates inhibition of replication, suggesting the involvement of N-CoR/SMRT. Py large T antigen interacts with mSin3B, suggesting an HDAC-independent mechanism by which mSin3B inhibits DNA replication.

Histone deacetylase 7 promotes Toll-like receptor 4-dependent proinflammatory gene expression in macrophages.

PubMed

Shakespear, Melanie R; Hohenhaus, Daniel M; Kelly, Greg M; Kamal, Nabilah A; Gupta, Praveer; Labzin, Larisa I; Schroder, Kate; Garceau, Valerie; Barbero, Sheila; Iyer, Abishek; Hume, David A; Reid, Robert C; Irvine, Katharine M; Fairlie, David P; Sweet, Matthew J

2013-08-30

Broad-spectrum inhibitors of histone deacetylases (HDACs) constrain Toll-like receptor (TLR)-inducible production of key proinflammatory mediators. Here we investigated HDAC-dependent inflammatory responses in mouse macrophages. Of the classical Hdacs, Hdac7 was expressed at elevated levels in inflammatory macrophages (thioglycollate-elicited peritoneal macrophages) as compared with bone marrow-derived macrophages and the RAW264 cell line. Overexpression of a specific, alternatively spliced isoform of Hdac7 lacking the N-terminal 22 amino acids (Hdac7-u), but not the Refseq Hdac7 (Hdac7-s), promoted LPS-inducible expression of Hdac-dependent genes (Edn1, Il-12p40, and Il-6) in RAW264 cells. A novel class IIa-selective HDAC inhibitor reduced recombinant human HDAC7 enzyme activity as well as TLR-induced production of inflammatory mediators in thioglycollate-elicited peritoneal macrophages. Both LPS and Hdac7-u up-regulated the activity of the Edn1 promoter in an HDAC-dependent fashion in RAW264 cells. A hypoxia-inducible factor (HIF) 1 binding site in this promoter was required for HDAC-dependent TLR-inducible promoter activity and for Hdac7- and HIF-1α-mediated trans-activation. Coimmunoprecipitation assays showed that both Hdac7-u and Hdac7-s interacted with HIF-1α, whereas only Hdac7-s interacted with the transcriptional repressor CtBP1. Thus, Hdac7-u positively regulates HIF-1α-dependent TLR signaling in macrophages, whereas an interaction with CtBP1 likely prevents Hdac7-s from exerting this effect. Hdac7 may represent a potential inflammatory disease target.

Histone Deacetylase 7 Promotes Toll-like Receptor 4-dependent Proinflammatory Gene Expression in Macrophages*

PubMed Central

Shakespear, Melanie R.; Hohenhaus, Daniel M.; Kelly, Greg M.; Kamal, Nabilah A.; Gupta, Praveer; Labzin, Larisa I.; Schroder, Kate; Garceau, Valerie; Barbero, Sheila; Iyer, Abishek; Hume, David A.; Reid, Robert C.; Irvine, Katharine M.; Fairlie, David P.; Sweet, Matthew J.

2013-01-01

Broad-spectrum inhibitors of histone deacetylases (HDACs) constrain Toll-like receptor (TLR)-inducible production of key proinflammatory mediators. Here we investigated HDAC-dependent inflammatory responses in mouse macrophages. Of the classical Hdacs, Hdac7 was expressed at elevated levels in inflammatory macrophages (thioglycollate-elicited peritoneal macrophages) as compared with bone marrow-derived macrophages and the RAW264 cell line. Overexpression of a specific, alternatively spliced isoform of Hdac7 lacking the N-terminal 22 amino acids (Hdac7-u), but not the Refseq Hdac7 (Hdac7-s), promoted LPS-inducible expression of Hdac-dependent genes (Edn1, Il-12p40, and Il-6) in RAW264 cells. A novel class IIa-selective HDAC inhibitor reduced recombinant human HDAC7 enzyme activity as well as TLR-induced production of inflammatory mediators in thioglycollate-elicited peritoneal macrophages. Both LPS and Hdac7-u up-regulated the activity of the Edn1 promoter in an HDAC-dependent fashion in RAW264 cells. A hypoxia-inducible factor (HIF) 1 binding site in this promoter was required for HDAC-dependent TLR-inducible promoter activity and for Hdac7- and HIF-1α-mediated trans-activation. Coimmunoprecipitation assays showed that both Hdac7-u and Hdac7-s interacted with HIF-1α, whereas only Hdac7-s interacted with the transcriptional repressor CtBP1. Thus, Hdac7-u positively regulates HIF-1α-dependent TLR signaling in macrophages, whereas an interaction with CtBP1 likely prevents Hdac7-s from exerting this effect. Hdac7 may represent a potential inflammatory disease target. PMID:23853092

Induction of colon and cervical cancer cell death by cinnamic acid derivatives is mediated through the inhibition of Histone Deacetylases (HDAC)

PubMed Central

Anantharaju, Preethi G.; Reddy, Deepa B.; Padukudru, Mahesh A.; Chitturi, CH. M. Kumari; Vimalambike, Manjunath G.

2017-01-01

Recent studies from our group and many others have shown the ability of histone deacetylase (HDAC) inhibitors for retarding the growth of carcinomas of cervix, colon and rectum in vitro. A search for naturally occurring HDAC inhibitors continues due to the adverse effects associated with known HDAC inhibitors like SAHA and TSA. Therefore in the current study, naturally occurring cinnamic acids derivatives were screened for HDAC inhibitory effect using in silico docking method which identified cinnamic acids as potential candidates. Cinnamic acids (CA) are naturally occurring phenolic compounds known to exhibit anticancer properties. However, it is not clearly known whether the anticancer properties of CA derivatives are due to the inhibition of oncogenic HDACs, if so how the efficacy varies among various CA derivatives. Hence, the HDAC inhibitory potential of CA derivatives containing increasing number of hydroxylic groups or methoxy moieties was determined using Discovery Studio software and the most potent CA derivatives tested ex vivo (biochemical assay) as well as in vitro (using cell based assay). Among CA derivatives tested, dihydroxy cinnamic acid (DHCA, commonly known as caffeic acid) exhibited better interactions with HDAC2 (compared to other isoforms) in silico and inhibited its activity ex vivo as well as in vitro. Targeted reduction of HDAC activity using DHCA induced death of cancer cells by (a) generating reactive oxygen species, (b) arresting cells in S and G2/M phases; and (c) induction of caspase-3 mediated apoptosis. In conclusion, we demonstrated that DHCA inhibited cancer cell growth by binding to HDAC followed by the induction of apoptosis. PMID:29190639

Induction of colon and cervical cancer cell death by cinnamic acid derivatives is mediated through the inhibition of Histone Deacetylases (HDAC).

PubMed

Anantharaju, Preethi G; Reddy, Deepa B; Padukudru, Mahesh A; Chitturi, Ch M Kumari; Vimalambike, Manjunath G; Madhunapantula, SubbaRao V

2017-01-01

Recent studies from our group and many others have shown the ability of histone deacetylase (HDAC) inhibitors for retarding the growth of carcinomas of cervix, colon and rectum in vitro. A search for naturally occurring HDAC inhibitors continues due to the adverse effects associated with known HDAC inhibitors like SAHA and TSA. Therefore in the current study, naturally occurring cinnamic acids derivatives were screened for HDAC inhibitory effect using in silico docking method which identified cinnamic acids as potential candidates. Cinnamic acids (CA) are naturally occurring phenolic compounds known to exhibit anticancer properties. However, it is not clearly known whether the anticancer properties of CA derivatives are due to the inhibition of oncogenic HDACs, if so how the efficacy varies among various CA derivatives. Hence, the HDAC inhibitory potential of CA derivatives containing increasing number of hydroxylic groups or methoxy moieties was determined using Discovery Studio software and the most potent CA derivatives tested ex vivo (biochemical assay) as well as in vitro (using cell based assay). Among CA derivatives tested, dihydroxy cinnamic acid (DHCA, commonly known as caffeic acid) exhibited better interactions with HDAC2 (compared to other isoforms) in silico and inhibited its activity ex vivo as well as in vitro. Targeted reduction of HDAC activity using DHCA induced death of cancer cells by (a) generating reactive oxygen species, (b) arresting cells in S and G2/M phases; and (c) induction of caspase-3 mediated apoptosis. In conclusion, we demonstrated that DHCA inhibited cancer cell growth by binding to HDAC followed by the induction of apoptosis.

Histone deacetylase inhibition increases levels of choline kinase α and phosphocholine facilitating noninvasive imaging in human cancers.

PubMed

Beloueche-Babari, Mounia; Arunan, Vaitha; Troy, Helen; te Poele, Robert H; te Fong, Anne-Christine Wong; Jackson, L Elizabeth; Payne, Geoffrey S; Griffiths, John R; Judson, Ian R; Workman, Paul; Leach, Martin O; Chung, Yuen-Li

2012-02-15

Histone deacetylase (HDAC) inhibitors are currently approved for cutaneous T-cell lymphoma and are in mid-late stage trials for other cancers. The HDAC inhibitors LAQ824 and SAHA increase phosphocholine (PC) levels in human colon cancer cells and tumor xenografts as observed by magnetic resonance spectroscopy (MRS). In this study, we show that belinostat, an HDAC inhibitor with an alternative chemical scaffold, also caused a rise in cellular PC content that was detectable by (1)H and (31)P MRS in prostate and colon carcinoma cells. In addition, (1)H MRS showed an increase in branched chain amino acid and alanine concentrations. (13)C-choline labeling indicated that the rise in PC resulted from increased de novo synthesis and correlated with an induction of choline kinase α expression. Furthermore, metabolic labeling experiments with (13)C-glucose showed that differential glucose routing favored alanine formation at the expense of lactate production. Additional analysis revealed increases in the choline/water and phosphomonoester (including PC)/total phosphate ratios in vivo. Together, our findings provide mechanistic insights into the impact of HDAC inhibition on cancer cell metabolism and highlight PC as a candidate noninvasive imaging biomarker for monitoring the action of HDAC inhibitors.

Epigenetic Regulation of the NR4A Orphan Nuclear Receptor NOR1 By Histone Acetylation

PubMed Central

Zhao, Yue; Nomiyama, Takashi; Findeisen, Hannes M.; Qing, Hua; Aono, Jun; Jones, Karrie L.; Heywood, Elizabeth B.; Bruemmer, Dennis

2014-01-01

The nuclear receptor NOR1 is an immediate-early response gene implicated in the transcriptional control of proliferation. Since the expression level of NOR1 is rapidly induced through cAMP response element binding (CREB) protein-dependent promoter activation, we investigated the contribution of histone acetylation to this transient induction. We demonstrate that NOR1 transcription is induced by histone deacetylase (HDAC) inhibition and by depletion of HDAC1 and HDAC3. HDAC inhibition activated the NOR1 promoter, increased histone acetylation and augmented the recruitment of phosphorylated CREB to the promoter. Furthermore, HDAC inhibition increased Ser133 phosphorylation of CREB and augmented NOR1 protein stability. These data outline previously unrecognized mechanisms of NOR1 regulation and illustrate a key role for histone acetylation in the rapid induction of NOR1. PMID:25451221

The proto-oncoprotein FBI-1 interacts with MBD3 to recruit the Mi-2/NuRD-HDAC complex and BCoR and to silence p21WAF/CDKN1A by DNA methylation

PubMed Central

Choi, Won-Il; Jeon, Bu-Nam; Yoon, Jae-Hyeon; Koh, Dong-In; Kim, Myung-Hwa; Yu, Mi-Young; Lee, Kyung-Mi; Kim, Youngsoo; Kim, Kyunggon; Hur, Sujin Susanne; Lee, Choong-Eun; Kim, Kyung-Sup; Hur, Man-Wook

2013-01-01

The tumour-suppressor gene CDKN1A (encoding p21Waf/Cip1) is thought to be epigenetically repressed in cancer cells. FBI-1 (ZBTB7A) is a proto-oncogenic transcription factor repressing the alternative reading frame and p21WAF/CDKN1A genes of the p53 pathway. FBI-1 interacts directly with MBD3 (methyl-CpG–binding domain protein 3) in the nucleus. We demonstrated that FBI-1 binds both non-methylated and methylated DNA and that MBD3 is recruited to the CDKN1A promoter through its interaction with FBI-1, where it enhances transcriptional repression by FBI-1. FBI-1 also interacts with the co-repressors nuclear receptor corepressor (NCoR), silencing mediator for retinoid and thyroid receptors (SMRT) and BCL-6 corepressor (BCoR) to repress transcription. MBD3 regulates a molecular interaction between the co-repressor and FBI-1. MBD3 decreases the interaction between FBI-1 and NCoR/SMRT but increases the interaction between FBI-1 and BCoR. Because MBD3 is a subunit of the Mi-2 autoantigen (Mi-2)/nucleosome remodelling and histone deacetylase (NuRD)-HDAC complex, FBI-1 recruits the Mi-2/NuRD-HDAC complex via MBD3. BCoR interacts with the Mi-2/NuRD-HDAC complex, DNMTs and HP1. MBD3 and BCoR play a significant role in the recruitment of the Mi-2/NuRD-HDAC complex– and the NuRD complex–associated proteins, DNMTs and HP. By recruiting DNMTs and HP1, Mi-2/NuRD-HDAC complex appears to play key roles in epigenetic repression of CDKN1A by DNA methylation. PMID:23658227

MicroRNA-29a Promotion of Nephrin Acetylation Ameliorates Hyperglycemia-Induced Podocyte Dysfunction

PubMed Central

Lin, Chun-Liang; Lee, Pei-Hsien; Hsu, Yung-Chien; Lei, Chen-Chou; Ko, Jih-Yang; Chuang, Pei-Chin; Huang, Yu-Ting; Wang, Shao-Yu; Wu, Shin-Long; Chen, Yu-Shan; Chiang, Wen-Chih; Reiser, Jochen

2014-01-01

Podocyte dysfunction is a detrimental feature in diabetic nephropathy, with loss of nephrin integrity contributing to diabetic podocytopathy. MicroRNAs (miRs) reportedly modulate the hyperglycemia-induced perturbation of renal tissue homeostasis. This study investigated whether regulation of histone deacetylase (HDAC) actions and nephrin acetylation by miR-29 contributes to podocyte homeostasis and renal function in diabetic kidneys. Hyperglycemia accelerated podocyte injury and reduced nephrin, acetylated nephrin, and miR-29a levels in primary renal glomeruli from streptozotocin-induced diabetic mice. Diabetic miR-29a transgenic mice had better nephrin levels, podocyte viability, and renal function and less glomerular fibrosis and inflammation reaction compared with diabetic wild-type mice. Overexpression of miR-29a attenuated the promotion of HDAC4 signaling, nephrin ubiquitination, and urinary nephrin excretion associated with diabetes and restored nephrin acetylation. Knockdown of miR-29a by antisense oligonucleotides promoted HDAC4 action, nephrin loss, podocyte apoptosis, and proteinuria in nondiabetic mice. In vitro, interruption of HDAC4 signaling alleviated the high glucose–induced apoptosis and inhibition of nephrin acetylation in podocyte cultures. Furthermore, HDAC4 interference increased the acetylation status of histone H3 at lysine 9 (H3K9Ac), the enrichment of H3K9Ac in miR-29a proximal promoter, and miR-29a transcription in high glucose–stressed podocytes. In conclusion, hyperglycemia impairs miR-29a signaling to intensify HDAC4 actions that contribute to podocyte protein deacetylation and degradation as well as renal dysfunction. HDAC4, via epigenetic H3K9 hypoacetylation, reduces miR-29a transcription. The renoprotective effects of miR-29a in diabetes-induced loss of podocyte integrity and renal homeostasis highlights the importance of post-translational acetylation reactions in podocyte microenvironments. Increasing miR-29a action may protect against diabetic podocytopathy. PMID:24578127

HDAC4: a key factor underlying brain developmental alterations in CDKL5 disorder.

PubMed

Trazzi, Stefania; Fuchs, Claudia; Viggiano, Rocchina; De Franceschi, Marianna; Valli, Emanuele; Jedynak, Paulina; Hansen, Finn K; Perini, Giovanni; Rimondini, Roberto; Kurz, Thomas; Bartesaghi, Renata; Ciani, Elisabetta

2016-09-15

Cyclin-dependent kinase-like 5 (CDKL5) is a Ser/Thr protein kinase predominantly expressed in the brain. Mutations of the CDKL5 gene lead to CDKL5 disorder, a neurodevelopmental pathology that shares several features with Rett Syndrome and is characterized by severe intellectual disability. The phosphorylation targets of CDKL5 are largely unknown, which hampers the discovery of therapeutic strategies for improving the neurological phenotype due to CDKL5 mutations. Here, we show that the histone deacetylase 4 (HDAC4) is a direct phosphorylation target of CDKL5 and that CDKL5-dependent phosphorylation promotes HDAC4 cytoplasmic retention. Nuclear HDAC4 binds to chromatin as well as to MEF2A transcription factor, leading to histone deacetylation and altered neuronal gene expression. By using a Cdkl5 knockout (Cdkl5 -/Y) mouse model, we found that hypophosphorylated HDAC4 translocates to the nucleus of neural precursor cells, thereby reducing histone 3 acetylation. This effect was reverted by re-expression of CDKL5 or by inhibition of HDAC4 activity through the HDAC4 inhibitor LMK235. In Cdkl5 -/Y mice treated with LMK235, defective survival and maturation of neuronal precursor cells and hippocampus-dependent memory were fully normalized. These results demonstrate a critical role of HDAC4 in the neurodevelopmental alterations due to CDKL5 mutations and suggest the possibility of HDAC4-targeted pharmacological interventions. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Connectivity map identifies HDAC inhibition as a treatment option of high-risk hepatoblastoma.

PubMed

Beck, Alexander; Eberherr, Corinna; Hagemann, Michaela; Cairo, Stefano; Häberle, Beate; Vokuhl, Christian; von Schweinitz, Dietrich; Kappler, Roland

2016-11-01

Hepatoblastoma (HB) is the most common liver tumor of childhood, usually occurring in children under the age of 3 y. The prognosis of patients presenting with distant metastasis, vascular invasion and advanced tumor stages remains poor and children that do survive often face severe late effects from the aggressive chemotherapy regimen. To identify potential new therapeutics for high risk HB we used a 1,000-gene expression signature as input for a Connectivity Map (CMap) analysis, which predicted histone deacetylase (HDAC) inhibitors as a promising therapy option. Subsequent expression analysis of primary HB and HB cell lines revealed a general overexpression of HDAC1 and HDAC2, which has been suggested to be predictive for the efficacy of HDAC inhibition. Accordingly, treatment of HB cells with the HDAC inhibitors SAHA and MC1568 resulted in a potent reduction of cell viability, induction of apoptosis, reactivation of epigenetically suppressed tumor suppressor genes, and the reversion of the 16-gene HB classifier toward the more favorable expression signature. Most importantly, the combination of HDAC inhibitors and cisplatin - a major chemotherapeutic agent of HB treatment - revealed a strong synergistic effect, even at significantly reduced doses of cisplatin. Our findings suggest that HDAC inhibitors skew HB cells toward a more favorable prognostic phenotype through changes in gene expression, thus indicating a targeted molecular mechanism that seems to enhance the anti-proliferative effects of conventional chemotherapy. Thus, adding HDAC inhibitors to the treatment regimen of high risk HB could potentially improve outcomes and reduce severe late effects.

Polycistronic tRNA and CRISPR guide-RNA enables highly efficient multiplexed genome engineering in human cells

PubMed Central

Dong, Fengping; Xie, Kabin; Chen, Yueying; Yang, Yinong; Mao, Yingwei

2016-01-01

CRISPR/Cas9 has been widely used for genomic editing in many organisms. Many human diseases are caused by multiple mutations. The CRISPR/Cas9 system provides a potential tool to introduce multiple mutations in a genome. To mimic complicated genomic variants in human diseases, such as multiple gene deletions or mutations, two or more small guide RNAs (sgRNAs) need to be introduced all together. This can be achieved by separate Pol III promoters in a construct. However, limited enzyme sites and increased insertion size lower the efficiency to make a construct. Here, we report a strategy to quickly assembly multiple sgRNAs in one construct using a polycistronic-tRNA-gRNA (PTG) strategy. Taking advantage of the endogenous tRNA processing system in mammalian cells, we efficiently express multiple sgRNAs driven using only one Pol III promoter. Using an all-in-one construct carrying PTG, we disrupt the deacetylase domain in multiple histone deacetylases (HDACs) in human cells simultaneously. We demonstrate that multiple HDAC deletions significantly affect the activation of the Wnt-signaling pathway. Thus, this method enables to efficiently target multiple genes and provide a useful tool to establish mutated cells mimicking human diseases. PMID:27890617

Polycistronic tRNA and CRISPR guide-RNA enables highly efficient multiplexed genome engineering in human cells.

PubMed

Dong, Fengping; Xie, Kabin; Chen, Yueying; Yang, Yinong; Mao, Yingwei

2017-01-22

CRISPR/Cas9 has been widely used for genomic editing in many organisms. Many human diseases are caused by multiple mutations. The CRISPR/Cas9 system provides a potential tool to introduce multiple mutations in a genome. To mimic complicated genomic variants in human diseases, such as multiple gene deletions or mutations, two or more small guide RNAs (sgRNAs) need to be introduced all together. This can be achieved by separate Pol III promoters in a construct. However, limited enzyme sites and increased insertion size lower the efficiency to make a construct. Here, we report a strategy to quickly assembly multiple sgRNAs in one construct using a polycistronic-tRNA-gRNA (PTG) strategy. Taking advantage of the endogenous tRNA processing system in mammalian cells, we efficiently express multiple sgRNAs driven using only one Pol III promoter. Using an all-in-one construct carrying PTG, we disrupt the deacetylase domain in multiple histone deacetylases (HDACs) in human cells simultaneously. We demonstrate that multiple HDAC deletions significantly affect the activation of the Wnt-signaling pathway. Thus, this method enables to efficiently target multiple genes and provide a useful tool to establish mutated cells mimicking human diseases. Copyright © 2016 Elsevier Inc. All rights reserved.

Persistently Altered Epigenetic Marks in the Mouse Uterus After Neonatal Estrogen Exposure

PubMed Central

Jefferson, Wendy N.; Chevalier, Dominique M.; Phelps, Jazma Y.; Cantor, Amy M.; Padilla-Banks, Elizabeth; Newbold, Retha R.; Archer, Trevor K.; Kinyamu, H. Karimi

2013-01-01

Neonatal exposure to diethylstilbestrol (DES) causes permanent alterations in female reproductive tract gene expression, infertility, and uterine cancer in mice. To determine whether epigenetic mechanisms could explain these phenotypes, we first tested whether DES altered uterine expression of chromatin-modifying proteins. DES treatment significantly reduced expression of methylcytosine dioxygenase TET oncogene family, member 1 (TET1) on postnatal day 5; this decrease was correlated with a subtle decrease in DNA 5-hydroxymethylcytosine in adults. There were also significant reductions in histone methyltransferase enhancer of zeste homolog 2 (EZH2), histone lysine acetyltransferase 2A (KAT2A), and histone deacetylases HDAC1, HDAC2, and HDAC3. Uterine chromatin immunoprecipitation was used to analyze the locus-specific association of modified histones with 2 genes, lactoferrin (Ltf) and sine oculis homeobox 1 (Six1), which are permanently upregulated in adults after neonatal DES treatment. Three histone modifications associated with active transcription, histone H3 lysine 9 acetylation (H3K9ac), H3 lysine 4 trimethylation (H3K4me3), and H4 lysine 5 acetylation (H4K5ac) were enriched at specific Ltf promoter regions after DES treatment, but this enrichment was not maintained in adults. H3K9ac, H4K5ac, and H3K4me3 were enriched at Six1 exon 1 immediately after neonatal DES treatment. As adults, DES-treated mice had greater differences in H4K5ac and H3K4me3 occupancy at Six1 exon 1 and new differences in these histone marks at an upstream region. These findings indicate that neonatal DES exposure temporarily alters expression of multiple chromatin-modifying proteins and persistently alters epigenetic marks in the adult uterus at the Six1 locus, suggesting a mechanism for developmental exposures leading to altered reproductive function and increased cancer risk. PMID:24002655

MUC1 Functions as a Oncogene by Targeting the Nucleus of Human Breast Cancer Cells

DTIC Science & Technology

2006-09-01

chromatin immunoprecipitation (ChIP) assays were performed on the p53 proximal promoter (PP; -118 to +14) with an anti-MUC1-C antibody (Fig. 3A). MUC1...assays were performed using anti-MUC1-C and anti-KLF4 antibodies . Analysis of MCF-7 and ZR-75-1 cells showed that anti-KLF4 precipitates the PE21 region...performed using anti-MUC1-C, anti-HDAC1 and HDAC3 antibodies . Analysis of MCF-7 and ZR-75-1 cells showed that anti-HDAC1 precipitates the PE21 region after

Design, synthesis and preliminary biological evaluation of indoline-2,3-dione derivatives as novel HDAC inhibitors.

PubMed

Jin, Kang; Li, Shanshan; Li, Xiaoguang; Zhang, Jian; Xu, Wenfang; Li, Xuechen

2015-08-01

Histone deacetylases (HDACs) are zinc-dependent or NAD(+) dependent enzymes and play a critical role in the process of tumor development. Herein a series of indoline-2,3-dione derivatives have been designed and synthesized as potential HDACs inhibitors. The preliminary biological evaluation showed that most compounds synthesized have exhibited moderate Hela cell nuclear extract inhibitory activities, among which compound 25a (IC50=10.13 nM) has shown the best efficacy. The anti-proliferative activities of some of these compounds were also discussed. Copyright © 2015. Published by Elsevier Ltd.

Selective inhibition of histone deacetylase 6 (HDAC6) induces DNA damage and sensitizes transformed cells to anticancer agents.

PubMed

Namdar, Mandana; Perez, Gisela; Ngo, Lang; Marks, Paul A

2010-11-16

Histone deacetylase 6 (HDAC6) is structurally and functionally unique among the 11 human zinc-dependent histone deacetylases. Here we show that chemical inhibition with the HDAC6-selective inhibitor tubacin significantly enhances cell death induced by the topoisomerase II inhibitors etoposide and doxorubicin and the pan-HDAC inhibitor SAHA (vorinostat) in transformed cells (LNCaP, MCF-7), an effect not observed in normal cells (human foreskin fibroblast cells). The inactive analogue of tubacin, nil-tubacin, does not sensitize transformed cells to these anticancer agents. Further, we show that down-regulation of HDAC6 expression by shRNA in LNCaP cells enhances cell death induced by etoposide, doxorubicin, and SAHA. Tubacin in combination with SAHA or etoposide is more potent than either drug alone in activating the intrinsic apoptotic pathway in transformed cells, as evidenced by an increase in PARP cleavage and partial inhibition of this effect by the pan-caspase inhibitor Z-VAD-fmk. HDAC6 inhibition with tubacin induces the accumulation of γH2AX, an early marker of DNA double-strand breaks. Tubacin enhances DNA damage induced by etoposide or SAHA as indicated by increased accumulation of γH2AX and activation of the checkpoint kinase Chk2. Tubacin induces the expression of DDIT3 (CHOP/GADD153), a transcription factor up-regulated in response to cellular stress. DDIT3 induction is further increased when tubacin is combined with SAHA. These findings point to mechanisms by which HDAC6-selective inhibition can enhance the efficacy of certain anti-cancer agents in transformed cells.

Regulation of Small Ubiquitin-Like Modifier-1, Nuclear Receptor Coreceptor, Histone Deacetylase 3, and Peroxisome Proliferator-Activated Receptor-γ in Human Adipose Tissue

PubMed Central

Bodles-Brakhop, Angela M.; Yao-Borengasser, Aiwei; Zhu, Beibei; Starnes, Catherine P.; McGehee, Robert E.; Peterson, Charlotte A.; Kern, Philip A.

2012-01-01

Abstract Background This study investigated the regulation of peroxisome proliferator-activated receptor-γ (PPARγ), the histone deacetylase 3 (HDAC3)–nuclear receptor coreceptor (NCoR) complex (a corepressor of transcription used by PPARγ), and small ubiquitin-like modifier-1 (SUMO-1) (a posttranslational modifier of PPARγ) in human adipose tissue and both adipocyte and macrophage cell lines. The objective was to determine whether there were alterations in the human adipose tissue gene expression levels of PPARγ, HDAC3, NCoR, and SUMO-1 associated either with obesity or with treatment of impaired glucose tolerance (IGT) subjects with insulin-sensitizing medications. Methods We obtained subcutaneous adipose tissue biopsies from 86 subjects with a wide range of body mass index (BMI) and insulin sensitivity (SI). Additionally, adipose tissue biopsies were obtained from a randomized subgroup of IGT subjects before and after 10 weeks of treatment with either pioglitazone or metformin. Results The adipose mRNA levels of PPARγ, NCoR, HDAC3, and SUMO-1 correlated strongly with each other (P<0.0001); however, SUMO-1, NCoR, and HDAC3 gene expression were not significantly associated with BMI or SI. Pioglitazone increased SUMO-1 expression by 23% (P<0.002) in adipose tissue and an adipocyte cell line (P<0.05), but not in macrophages. Small interfering RNA (siRNA)-mediated knockdown of SUMO-1 decreased PPARγ, HDAC3, and NCoR in THP-1 cells and increased tumor necrosis factor-α (TNF-α) induction in response to lipopolysaccharide (LPS). Conclusions These results suggest that the coordinate regulation of SUMO-1, PPARγ1/2, HDAC3, and NCoR may be more tightly controlled in macrophages than in adipocytes in human adipose and that these modulators of PPARγ activity may be particularly important in the negative regulation of macrophage-mediated adipose inflammation by pioglitazone. PMID:22651256

Gain-of-function STAT1 mutations impair STAT3 activity in patients with chronic mucocutaneous candidiasis (CMC).

PubMed

Zheng, Jie; van de Veerdonk, Frank L; Crossland, Katherine L; Smeekens, Sanne P; Chan, Chun M; Al Shehri, Tariq; Abinun, Mario; Gennery, Andrew R; Mann, Jelena; Lendrem, Dennis W; Netea, Mihai G; Rowan, Andrew D; Lilic, Desa

2015-10-01

Signal transducer and activator of transcription 3 (STAT3) triggered production of Th-17 cytokines mediates protective immunity against fungi. Mutations affecting the STAT3/interleukin 17 (IL-17) pathway cause selective susceptibility to fungal (Candida) infections, a hallmark of chronic mucocutaneous candidiasis (CMC). In patients with autosomal dominant CMC, we and others previously reported defective Th17 responses and underlying gain-of-function (GOF) STAT1 mutations, but how this affects STAT3 function leading to decreased IL-17 is unclear. We also assessed how GOF-STAT1 mutations affect STAT3 activation, DNA binding, gene expression, cytokine production, and epigenetic modifications. We excluded impaired STAT3 phosphorylation, nuclear translocation, and sequestration of STAT3 into STAT1/STAT3 heterodimers and confirm significantly reduced transcription of STAT3-inducible genes (RORC/IL-17/IL-22/IL-10/c-Fos/SOCS3/c-Myc) as likely underlying mechanism. STAT binding to the high affinity sis-inducible element was intact but binding to an endogenous STAT3 DNA target was impaired. Reduced STAT3-dependent gene transcription was reversed by inhibiting STAT1 activation with fludarabine or enhancing histone, but not STAT1 or STAT3 acetylation with histone deacetylase (HDAC) inhibitors trichostatin A or ITF2357. Silencing HDAC1, HDAC2, and HDAC3 indicated a role for HDAC1 and 2. Reduced STAT3-dependent gene transcription underlies low Th-17 responses in GOF-STAT1 CMC, which can be reversed by inhibiting acetylation, offering novel targets for future therapies. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Epigenetic regulation of the NR4A orphan nuclear receptor NOR1 by histone acetylation.

PubMed

Zhao, Yue; Nomiyama, Takashi; Findeisen, Hannes M; Qing, Hua; Aono, Jun; Jones, Karrie L; Heywood, Elizabeth B; Bruemmer, Dennis

2014-12-20

The nuclear receptor NOR1 is an immediate-early response gene implicated in the transcriptional control of proliferation. Since the expression level of NOR1 is rapidly induced through cAMP response element binding (CREB) protein-dependent promoter activation, we investigated the contribution of histone acetylation to this transient induction. We demonstrate that NOR1 transcription is induced by histone deacetylase (HDAC) inhibition and by depletion of HDAC1 and HDAC3. HDAC inhibition activated the NOR1 promoter, increased histone acetylation and augmented the recruitment of phosphorylated CREB to the promoter. Furthermore, HDAC inhibition increased Ser133 phosphorylation of CREB and augmented NOR1 protein stability. These data outline previously unrecognized mechanisms of NOR1 regulation and illustrate a key role for histone acetylation in the rapid induction of NOR1. Copyright © 2014 Federation of European Biochemical Societies. Published by Elsevier B.V. All rights reserved.

Identification of novel potential scaffold for class I HDACs inhibition: An in-silico protocol based on virtual screening, molecular dynamics, mathematical analysis and machine learning.

PubMed

Fan, Cong; Huang, Yanxin

2017-09-23

Histone deacetylases (HDACs) family has been widely reported as an important class of enzyme targets for cancer therapy. Much effort has been made in discovery of novel scaffolds for HDACs inhibition besides existing hydroxamic acids, cyclic peptides, benzamides, and short-chain fatty acids. Herein we set up an in-silico protocol which not only could detect potential Zn 2+ chelation bonds but also still adopted non-bonded model to be effective in discovery of Class I HDACs inhibitors, with little human's subjective visual judgment involved. We applied the protocol to screening of Chembridge database and selected out 7 scaffolds, 3 with probability of more than 99%. Biological assay results demonstrated that two of them exhibited HDAC-inhibitory activity and are thus considerable for structure modification to further improve their bio-activity. Copyright © 2017. Published by Elsevier Inc.

Differentiation and upregulation of heat shock protein 70 induced by a subset of histone deacetylase inhibitors in mouse and human embryonic stem cells.

PubMed

Park, Jeong-A; Kim, Young-Eun; Seok, Hyun-Jeong; Park, Woo-Youn; Kwon, Hyung-Joo; Lee, Younghee

2011-03-01

Inhibiting histone deacetylase (HDAC) activity modulates the epigenetic status of cells, resulting in an alteration of gene expression and cellular function. Here, we investigated the effects of HDAC inhibitors on mouse embryonic stem (ES) cells. The HDAC inhibitors trichostatin A, suberoylanilide hydroxamic acid, sodium butyrate, and valproic acid induced early differentiation of mouse ES cells and triggered induction of heatshock protein (HSP)70. In contrast, class III HDAC inhibitors failed to induce differentiation or HSP70 expression. Transcriptional upregulation of HSP70 was confirmed by mRNA expression analysis, an inhibitor study, and chromatin immunoprecipitation. HSP70 induction was dependent on the SAPK/ JNK, p38, and PI3K/Akt pathways. Differentiation and induction of HSP70 by a subset of HDAC inhibitors was also examined in human ES cells, which suggests that the phenomenon generally occurs in ES cells. A better understanding of the effects of HDAC inhibitors may give more insight into their application in stem cell biology.

Inhibition of Plasmodium falciparum proliferation in vitro by double-stranded RNA directed against malaria histone deacetylase

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sriwilaijaroen, N.; Boonma, S.; Attasart, P.

Acetylation and deacetylation of histones play important roles in transcription regulation, cell cycle progression and development events. The steady state status of histone acetylation is controlled by a dynamic equilibrium between competing histone acetylase and deacetylase (HDAC). We have used long PfHDAC-1 double-stranded (ds)RNA to interfere with its cognate mRNA expression and determined the effect on malaria parasite growth and development. Chloroquine- and pyrimethamine-resistant Plasmodium falciparum K1 strain was exposed to 1-25 {mu}g of dsRNA/ml of culture for 48 h and growth was determined by [{sup 3}H]-hypoxanthine incorporation and microscopic examination. Parasite culture treated with 10 {mu}g/ml pfHDAC-1 dsRNA exhibitedmore » 47% growth inhibition when compared with either untreated control or culture treated with an unrelated dsRNA. PfHDAC-1 dsRNA specifically blocked maturation of trophozoite to schizont stages and decreased PfHDAC-1 transcript 44% in treated trophozoites. These results indicate the potential of HDAC-1 as a target for development of novel antimalarials.« less

Suppression of class I and II histone deacetylases blunts pressure-overload cardiac hypertrophy.

PubMed

Kong, Yongli; Tannous, Paul; Lu, Guangrong; Berenji, Kambeez; Rothermel, Beverly A; Olson, Eric N; Hill, Joseph A

2006-06-06

Recent work has demonstrated the importance of chromatin remodeling, especially histone acetylation, in the control of gene expression in the heart. In cell culture models of cardiac hypertrophy, pharmacological suppression of histone deacetylases (HDACs) can either blunt or amplify cell growth. Thus, HDAC inhibitors hold promise as potential therapeutic agents in hypertrophic heart disease. In the present investigation, we studied 2 broad-spectrum HDAC inhibitors in a physiologically relevant banding model of hypertrophy, observing dose-responsive suppression of ventricular growth that was well tolerated in terms of both clinical outcome and cardiac performance measures. In both short-term (3-week) and long-term (9-week) trials, cardiomyocyte growth was blocked by HDAC inhibition, with no evidence of cell death or apoptosis. Fibrotic change was diminished in hearts treated with HDAC inhibitors, and collagen synthesis in isolated cardiac fibroblasts was blocked. Preservation of systolic function in the setting of blunted hypertrophic growth was documented by echocardiography and by invasive pressure measurements. The hypertrophy-associated switch of adult and fetal isoforms of myosin heavy chain expression was attenuated, which likely contributed to the observed preservation of systolic function in HDAC inhibitor-treated hearts. Together, these data suggest that HDAC inhibition is a viable therapeutic strategy that holds promise in the treatment of load-induced heart disease.

Targeting Deacetylases to Improve Outcomes after Allogeneic Bone Marrow Transplantation

PubMed Central

Reddy, Pavan

2013-01-01

Graft-versus-host disease (GVHD) is the major complication of allogeneic bone marrow transplantation (BMT). GVHD is a complex immunologically mediated biological process. Recent data have shown that histone deacetylase inhibitors (HDACis) have potent anti-inflammatory effects. We have been studying the role of acetylation through inhibition of histone deacetylases (HDACs) in modulating immunity, specifically, GVHD. HDAC inhibition regulates GVHD, at least in part, through suppression of the function of host antigen presenting cells such as dendritic cells (DCs). HDACis reduce DC responses by enhancing the expression of indoleamine 2,3 dioxygenase (IDO) in a STAT-3–dependent manner. They also alter the function of other immune cells such as T regulatory cells and NK cells, which also play important roles in the biology of GVHD. Based on these observations, a clinical trial has been launched to evaluate its impact on clinical GVHD. The clinical features, biology of GVHD, the experimental studies with HDACis, and preliminary observations from humans are discussed. PMID:23874019

Downregulation of HDAC9 inhibits cell proliferation and tumor formation by inducing cell cycle arrest in retinoblastoma

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhang, Yiting; Wu, Dan; Xia, Fengjie

Histone deacetylase 9 (HDAC9) is a member of class II HDACs, which regulates a wide variety of normal and abnormal physiological functions. Recently, HDAC9 has been found to be overexpressed in some types of human cancers. However, the role of HDAC9 in retinoblastoma remains unclear. In this study, we found that HDAC9 was commonly expressed in retinoblastoma tissues and HDAC9 was overexpressed in prognostically poor retinoblastoma patients. Through knocking down HDAC9 in Y79 and WERI-Rb-1 cells, the expression level of HDAC9 was found to be positively related to cell proliferation in vitro. Further investigation indicated that knockdown HDAC9 could significantly induce cellmore » cycle arrest at G1 phase in retinoblastoma cells. Western blot assay showed downregulation of HDAC9 could significantly decrease cyclin E2 and CDK2 expression. Lastly, xenograft study in nude mice showed that downregulation of HDAC9 inhibited tumor growth and development in vivo. Therefore, our results suggest that HDAC9 could serve as a novel potential therapeutic target in the treatment of retinoblastoma. - Highlights: • High expression of HDAC9 correlates with poor patient prognosis. • Downregulation of HDAC9 inhibits cell proliferation in retinoblastoma cells. • Downregulation of HDAC9 induces cell cycle arrest at G1 phase in retinoblastoma cells. • Downregulation of HDAC9 suppresses tumor growth in nude mice.« less

Loss of the deubiquitylase BAP1 alters class I histone deacetylase expression and sensitivity of mesothelioma cells to HDAC inhibitors

PubMed Central

Sacco, Joseph J.; Kenyani, Jenna; Butt, Zohra; Carter, Rachel; Chew, Hui Yi; Cheeseman, Liam P.; Darling, Sarah; Denny, Michael; Urbé, Sylvie; Clague, Michael J.; Coulson, Judy M.

2015-01-01

Histone deacetylases are important targets for cancer therapeutics, but their regulation is poorly understood. Our data show coordinated transcription of HDAC1 and HDAC2 in lung cancer cell lines, but suggest HDAC2 protein expression is cell-context specific. Through an unbiased siRNA screen we found that BRCA1-associated protein 1 (BAP1) regulates their expression, with HDAC2 reduced and HDAC1 increased in BAP1 depleted cells. BAP1 loss-of-function is increasingly reported in cancers including thoracic malignancies, with frequent mutation in malignant pleural mesothelioma. Endogenous HDAC2 directly correlates with BAP1 across a panel of lung cancer cell lines, and is downregulated in mesothelioma cell lines with genetic BAP1 inactivation. We find that BAP1 regulates HDAC2 by increasing transcript abundance, rather than opposing its ubiquitylation. Importantly, although total cellular HDAC activity is unaffected by transient depletion of HDAC2 or of BAP1 due to HDAC1 compensation, this isoenzyme imbalance sensitizes MSTO-211H cells to HDAC inhibitors. However, other established mesothelioma cell lines with low endogenous HDAC2 have adapted to become more resistant to HDAC inhibition. Our work establishes a mechanism by which BAP1 loss alters sensitivity of cancer cells to HDAC inhibitors. Assessment of BAP1 and HDAC expression may ultimately help identify patients likely to respond to HDAC inhibitors. PMID:25970771

The first familial case of inherited 2q37.3 interstitial deletion with isolated skeletal abnormalities including brachydactyly type E and short stature.

PubMed

Jean-Marçais, Nolwenn; Decamp, Matthieu; Gérard, Marion; Ribault, Virginie; Andrieux, Joris; Kottler, Marie-Laure; Plessis, Ghislaine

2015-01-01

Albright hereditary osteodystrophy (AHO)-like syndrome is also known as brachydactyly-mental retardation syndrome (BDMR; OMIM 60040). This disorder includes intellectual disability in all patients, skeletal abnormalities, including brachydactyly E (BDE) in approximately half, obesity, and facial dysmorphism. Patients with 2q37 microdeletion or HDAC4 mutation are defined as having an AHO-like phenotype with normal stimulatory G (Gs) function. HDAC4 is involved in neurological, cardiac, and skeletal function. This paper reports the first familial case of 2q37.3 interstitial deletion affecting two genes, HDAC4 and TWIST2. Patients presented with BDE and short stature without intellectual disability, showing that haploinsufficiency of the HDAC4 critical region may lead to a spectrum of phenotypes, ranging from isolated brachydactyly type E to BDMR. © 2014 Wiley Periodicals, Inc.

Suppression of Akt-mediated HDAC3 expression and CDK2 T39 phosphorylation by a bichalcone analog contributes to S phase retardation of cancer cells.

PubMed

Hung, Kuang-Chen; Lin, Meng-Liang; Hsu, Shih-Wei; Lee, Chuan-Chun; Huang, Ren-Yu; Wu, Tian-Shung; Chen, Shih-Shun

2018-06-15

Targeting cell cycle regulators has been a suggested mechanism for therapeutic cancer strategies. We report here that the bichalcone analog TSWU-CD4 induces S phase arrest of human cancer cells by inhibiting the formation of cyclin A-phospho (p)-cyclin-dependent kinase 2 (CDK2, threonine [Thr] 39) complexes, independent of mutant p53 expression. Ectopic expression of CDK2 (T39E), which mimics phosphorylation of the Thr 39 residue of CDK2, partially rescues the cells from TSWU-CD4-induced S phase arrest, whereas phosphorylation-deficient CDK2 (T39A) expression regulates cell growth with significant S phase arrest and enhances TSWU-CD4-triggered S phase arrest. Decreased histone deacetylase 3 (HDAC3) expression after TSWU-CD4 treatment was demonstrated, and TSWU-CD4 induced S phase arrest and inhibitory effects on cyclin A expression and CDK2 Thr 39 phosphorylation, while cyclin A-p-CDK2 (Thr 39) complex formation was suppressed by ectopic wild-type HDAC3 expression. The co-transfection of CDK2 (T39E) along with HDAC3 completely restored cyclin A expression, Thr 39-phosphorylated CDK2, cyclin A-p-CDK2 (Thr 39) complex formation, and the S phase population to normal levels. Protein kinase B (Akt) inactivation was required for TSWU-CD4-induced S phase cell cycle arrest, because constitutively active Akt1 blocks the induction of S phase arrest and the suppression of cyclin A and HDAC3 expression, CDK2 Thr 39 phosphorylation, and cyclin A-p-CDK2 (Thr 39) complex formation by TSWU-CD4. Taken together, our results indicate that TSWU-CD4 induces S phase arrest by inhibiting Akt-mediated HDAC3 expression and CDK2 Thr 39 phosphorylation to suppress the formation of cyclin A-p-CDK2 (Thr 39) complexes. Copyright © 2018 Elsevier B.V. All rights reserved.

HDAC 1 and 6 modulate cell invasion and migration in clear cell renal cell carcinoma.

PubMed

Ramakrishnan, Swathi; Ku, ShengYu; Ciamporcero, Eric; Miles, Kiersten Marie; Attwood, Kris; Chintala, Sreenivasulu; Shen, Li; Ellis, Leigh; Sotomayor, Paula; Swetzig, Wendy; Huang, Ray; Conroy, Dylan; Orillion, Ashley; Das, Gokul; Pili, Roberto

2016-08-09

Class I histone deacetylases (HDACs) have been reported to be overexpressed in clear cell renal cell carcinoma (ccRCC), whereas the expression of class II HDACs is unknown. Four isogenic cell lines C2/C2VHL and 786-O/786-OVHL with differential VHL expression are used in our studies. Cobalt chloride is used to mimic hypoxia in vitro. HIF-2α knockdowns in C2 and 786-O cells is used to evaluate the effect on HDAC 1 expression and activity. Invasion and migration assays are used to investigate the role of HDAC 1 and HDAC 6 expression in ccRCC cells. Comparisons are made between experimental groups using the paired T-test, the two-sample Student's T-test or one-way ANOVA, as appropriate. ccRCC and the TCGA dataset are used to observe the clinical correlation between HDAC 1 and HDAC 6 overexpression and overall and progression free survival. Our analysis of tumor and matched non-tumor tissues from radical nephrectomies showed overexpression of class I and II HDACs (HDAC6 only in a subset of patients). In vitro, both HDAC1 and HDAC6 over-expression increased cell invasion and motility, respectively, in ccRCC cells. HDAC1 regulated invasiveness by increasing matrix metalloproteinase (MMP) expression. Furthermore, hypoxia stimulation in VHL-reconstituted cell lines increased HIF isoforms and HDAC1 expression. Presence of hypoxia response elements in the HDAC1 promoter along with chromatin immunoprecipitation data suggests that HIF-2α is a transcriptional regulator of HDAC1 gene. Conversely, HDAC6 and estrogen receptor alpha (ERα) were co-localized in cytoplasm of ccRCC cells and HDAC6 enhanced cell motility by decreasing acetylated α-tubulin expression, and this biological effect was attenuated by either biochemical or pharmacological inhibition. Finally, analysis of human ccRCC specimens revealed positive correlation between HIF isoforms and HDAC. HDAC1 mRNA upregulation was associated with worse overall survival in the TCGA dataset. Taking together, these results suggest that HDAC1 and HDAC6 may play a role in ccRCC biology and could represent rational therapeutic targets.

A novel HDAC inhibitor, CG200745, inhibits pancreatic cancer cell growth and overcomes gemcitabine resistance.

PubMed

Lee, Hee Seung; Park, Soo Been; Kim, Sun A; Kwon, Sool Ki; Cha, Hyunju; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung; Song, Si Young

2017-01-30

Pancreatic cancer is predominantly lethal, and is primarily treated using gemcitabine, with increasing resistance. Therefore, novel agents that increase tumor sensitivity to gemcitabine are needed. Histone deacetylase (HDAC) inhibitors are emerging therapeutic agents, since HDAC plays an important role in cancer initiation and progression. We evaluated the antitumor effect of a novel HDAC inhibitor, CG200745, combined with gemcitabine/erlotinib on pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells. Three pancreatic cancer-cell lines were used to evaluate the antitumor effect of CG200745 combined with gemcitabine/erlotinib. CG200745 induced the expression of apoptotic proteins (PARP and caspase-3) and increased the levels of acetylated histone H3. CG200745 with gemcitabine/erlotinib showed significant growth inhibition and synergistic antitumor effects in vitro. In vivo, gemcitabine/erlotinib and CG200745 reduced tumor size up to 50%. CG200745 enhanced the sensitivity of gemcitabine-resistant pancreatic cancer cells to gemcitabine, and decreased the level of ATP-binding cassette-transporter genes, especially multidrug resistance protein 3 (MRP3) and MRP4. The novel HDAC inhibitor, CG200745, with gemcitabine/erlotinib had a synergistic anti-tumor effect on pancreatic cancer cells. CG200745 significantly improved pancreatic cancer sensitivity to gemcitabine, with a prominent antitumor effect on gemcitabine-resistant pancreatic cancer cells. Therefore, improved clinical outcome is expected in the future.

A novel HDAC inhibitor, CG200745, inhibits pancreatic cancer cell growth and overcomes gemcitabine resistance

PubMed Central

Lee, Hee Seung; Park, Soo Been; Kim, Sun A; Kwon, Sool Ki; Cha, Hyunju; Lee, Do Young; Ro, Seonggu; Cho, Joong Myung; Song, Si Young

2017-01-01

Pancreatic cancer is predominantly lethal, and is primarily treated using gemcitabine, with increasing resistance. Therefore, novel agents that increase tumor sensitivity to gemcitabine are needed. Histone deacetylase (HDAC) inhibitors are emerging therapeutic agents, since HDAC plays an important role in cancer initiation and progression. We evaluated the antitumor effect of a novel HDAC inhibitor, CG200745, combined with gemcitabine/erlotinib on pancreatic cancer cells and gemcitabine-resistant pancreatic cancer cells. Three pancreatic cancer-cell lines were used to evaluate the antitumor effect of CG200745 combined with gemcitabine/erlotinib. CG200745 induced the expression of apoptotic proteins (PARP and caspase-3) and increased the levels of acetylated histone H3. CG200745 with gemcitabine/erlotinib showed significant growth inhibition and synergistic antitumor effects in vitro. In vivo, gemcitabine/erlotinib and CG200745 reduced tumor size up to 50%. CG200745 enhanced the sensitivity of gemcitabine-resistant pancreatic cancer cells to gemcitabine, and decreased the level of ATP-binding cassette-transporter genes, especially multidrug resistance protein 3 (MRP3) and MRP4. The novel HDAC inhibitor, CG200745, with gemcitabine/erlotinib had a synergistic anti-tumor effect on pancreatic cancer cells. CG200745 significantly improved pancreatic cancer sensitivity to gemcitabine, with a prominent antitumor effect on gemcitabine-resistant pancreatic cancer cells. Therefore, improved clinical outcome is expected in the future. PMID:28134290

A ruthenium anticancer compound interacts with histones and impacts differently on epigenetic and death pathways compared to cisplatin

PubMed Central

Capuozzo, Antonelle; Ali, Moussa; Santamaria, Rita; Armant, Olivier; Delalande, Francois; Dorsselaer, Alain Van; Cianferani, Sarah; Spencer, John; Pfeffer, Michel; Mellitzer, Georg; Gaiddon, Christian

2017-01-01

Ruthenium complexes are considered as potential replacements for platinum compounds in oncotherapy. Their clinical development is handicapped by a lack of consensus on their mode of action. In this study, we identify three histones (H3.1, H2A, H2B) as possible targets for an anticancer redox organoruthenium compound (RDC11). Using purified histones, we confirmed an interaction between the ruthenium complex and histones that impacted on histone complex formation. A comparative study of the ruthenium complex versus cisplatin showed differential epigenetic modifications on histone H3 that correlated with differential expression of histone deacetylase (HDAC) genes. We then characterized the impact of these epigenetic modifications on signaling pathways employing a transcriptomic approach. Clustering analyses showed gene expression signatures specific for cisplatin (42%) and for the ruthenium complex (30%). Signaling pathway analyses pointed to specificities distinguishing the ruthenium complex from cisplatin. For instance, cisplatin triggered preferentially p53 and folate biosynthesis while the ruthenium complex induced endoplasmic reticulum stress and trans-sulfuration pathways. To further understand the role of HDACs in these regulations, we used suberanilohydroxamic acid (SAHA) and showed that it synergized with cisplatin cytotoxicity while antagonizing the ruthenium complex activity. This study provides critical information for the characterization of signaling pathways differentiating both compounds, in particular, by the identification of a non-DNA direct target for an organoruthenium complex. PMID:27935863

Subchondral mesenchymal stem cells from osteoarthritic knees display high osteogenic differentiation capacity through microRNA-29a regulation of HDAC4.

PubMed

Lian, Wei-Shiung; Wu, Ren-Wen; Lee, Mel S; Chen, Yu-Shan; Sun, Yi-Chih; Wu, Shing-Long; Ke, Huei-Jing; Ko, Jih-Yang; Wang, Feng-Sheng

2017-12-01

Subchondral bone deterioration and osteophyte formation attributable to excessive mineralization are prominent features of end-stage knee osteoarthritis (OA). The cellular events underlying subchondral integrity diminishment remained elusive. This study was undertaken to characterize subchondral mesenchymal stem cells (SMSCs) isolated from patients with end-stage knee OA who required total knee arthroplasty. The SMSCs expressed surface antigens CD29, CD44, CD73, CD90, CD105, and CD166 and lacked CD31, CD45, and MHCII expression. The cell cultures exhibited higher proliferation and greater osteogenesis and chondrogenesis potencies, whereas their population-doubling time and adipogenic lineage commitment were lower than those of bone marrow MSCs (BMMSCs). They also displayed higher expressions of embryonic stem cell marker OCT3/4 and osteogenic factors Wnt3a, β-catenin, and microRNA-29a (miR-29a), concomitant with lower expressions of joint-deleterious factors HDAC4, TGF-β1, IL-1β, TNF-α, and MMP3, in comparison with those of BMMSCs. Knockdown of miR-29a lowered Wnt3a expression and osteogenic differentiation of the SMSCs through elevating HDAC4 translation, which directly regulated the 3'-untranslated region of HDAC4. Likewise, transgenic mice that overexpressed miR-29a in osteoblasts exhibited a high bone mass in the subchondral region. SMSCs in the transgenic mice showed a higher osteogenic differentiation and lower HDAC4 signaling than those in wild-type mice. Taken together, high osteogenesis potency existed in the SMSCs in the osteoarthritic knee. The miR-29a modulation of HDAC4 and Wnt3a signaling was attributable to the increase in osteogenesis. This study shed an emerging light on the characteristics of SMSCs and highlighted the contribution of SMSCs in the exacerbation of subchondral integrity in end-stage knee OA. Subchondral MSCs (SMSCs) from OA knee expressed embryonic stem cell marker Oct3/4. The SMSCs showed high proliferation and osteogenic and chondrogenic potencies. miR-29a regulated osteogenesis of the SMSCs through modulation of HDAC4 and Wnt3a. A high osteogenic potency of the SMSCs existed in mice overexpressing miR-29a in bone. Aberrant osteogenesis in SMSCs provides a new insight to subchondral damage in OA.

HDAC9 promotes glioblastoma growth via TAZ-mediated EGFR pathway activation.

PubMed

Yang, Rui; Wu, Yanan; Wang, Mei; Sun, Zhongfeng; Zou, Jiahua; Zhang, Yundong; Cui, Hongjuan

2015-04-10

Histone deacetylase 9 (HDAC9), a member of class II HDACs, regulates a wide variety of normal and abnormal physiological functions. We found that HDAC9 is over-expressed in prognostically poor glioblastoma patients. Knockdown HDAC9 decreased proliferation in vitro and tumor formation in vivo. HDAC9 accelerated cell cycle in part by potentiating the EGFR signaling pathway. Also, HDAC9 interacted with TAZ, a key downstream effector of Hippo pathway. Knockdown of HDAC9 decreased the expression of TAZ. We found that overexpressed TAZ in HDAC9-knockdown cells abrogated the effects induced by HDAC9 silencing both in vitro and in vivo. We demonstrated that HDAC9 promotes tumor formation of glioblastoma via TAZ-mediated EGFR pathway activation, and provide the evidence for promising target for the treatment of glioblastoma.

Downregulation of Homologous Recombination DNA Repair Genes by HDAC Inhibition in Prostate Cancer Is Mediated through the E2F1 Transcription Factor

PubMed Central

Kachhap, Sushant K.; Rosmus, Nadine; Collis, Spencer J.; Kortenhorst, Madeleine S. Q.; Wissing, Michel D.; Hedayati, Mohammad; Shabbeer, Shabana; Mendonca, Janet; Deangelis, Justin; Marchionni, Luigi; Lin, Jianqing; Höti, Naseruddin; Nortier, Johan W. R.; DeWeese, Theodore L.; Hammers, Hans; Carducci, Michael A.

2010-01-01

Background Histone deacetylase inhibitors (HDACis) re-express silenced tumor suppressor genes and are currently undergoing clinical trials. Although HDACis have been known to induce gene expression, an equal number of genes are downregulated upon HDAC inhibition. The mechanism behind this downregulation remains unclear. Here we provide evidence that several DNA repair genes are downregulated by HDAC inhibition and provide a mechanism involving the E2F1 transcription factor in the process. Methodology/Principal Findings Applying Analysis of Functional Annotation (AFA) on microarray data of prostate cancer cells treated with HDACis, we found a number of genes of the DNA damage response and repair pathways are downregulated by HDACis. AFA revealed enrichment of homologous recombination (HR) DNA repair genes of the BRCA1 pathway, as well as genes regulated by the E2F1 transcription factor. Prostate cancer cells demonstrated a decreased DNA repair capacity and an increased sensitization to chemical- and radio-DNA damaging agents upon HDAC inhibition. Recruitment of key HR repair proteins to the site of DNA damage, as well as HR repair capacity was compromised upon HDACi treatment. Based on our AFA data, we hypothesized that the E2F transcription factors may play a role in the downregulation of key repair genes upon HDAC inhibition in prostate cancer cells. ChIP analysis and luciferase assays reveal that the downregulation of key repair genes is mediated through decreased recruitment of the E2F1 transcription factor and not through active repression by repressive E2Fs. Conclusions/Significance Our study indicates that several genes in the DNA repair pathway are affected upon HDAC inhibition. Downregulation of the repair genes is on account of a decrease in amount and promoter recruitment of the E2F1 transcription factor. Since HDAC inhibition affects several pathways that could potentially have an impact on DNA repair, compromised DNA repair upon HDAC inhibition could also be attributed to several other pathways besides the ones investigated in this study. However, our study does provide insights into the mechanism that governs downregulation of HR DNA repair genes upon HDAC inhibition, which can lead to rationale usage of HDACis in the clinics. PMID:20585447

AP-1 mediated transcriptional repression of matrix metalloproteinase-9 by recruitment of histone deacetylase 1 in response to interferon β.

PubMed

Mittelstadt, Megan L; Patel, Rekha C

2012-01-01

Matrix metalloproteinase-9 (MMP-9) is a 92 kDa zinc-dependant endopeptidase that degrades components of the extracellular matrix. Increased expression of MMP-9 is implicated in many pathological conditions including metastatic cancer, multiple sclerosis, and atherosclerosis. Although it has been widely noted that interferon-β (IFNβ) downregulates both the basal and phorbol 12-myristate 13-acetate (PMA)-induced MMP-9 expression at the transcriptional level, the molecular mechanism of this repression is poorly understood. In the present study we identify a novel mechanism for repression of MMP-9 transcription by IFNβ in HT1080 fibrosarcoma cells. Using reporter assays with promoter deletion constructs we show that IFNβ's inhibitory effects require a region of the promoter between -154 and -72, which contains an AP-1 binding site. Chromatin immunoprecipitation (ChIP) studies indicate that IFNβ increases histone deacetylase (HDAC)-1 recruitment to the MMP-9 promoter and reduces histone H3 acetylation, in addition to reduced NF-κB recruitment. ChIP analysis shows that IFNβ induced HDAC1 recruitment to the MMP-9 promoter and IFNβ mediated transcriptional repression is lost when the AP-1 binding site is inactivated by a point mutation. Altogether, our results establish that the repression of MMP-9 transcription in response to IFNβ occurs by the recruitment of HDAC1 via the proximal AP-1 binding site.

HDAC and HDAC Inhibitor: From Cancer to Cardiovascular Diseases

PubMed Central

Yoon, Somy

2016-01-01

Histone deacetylases (HDACs) are epigenetic regulators that regulate the histone tail, chromatin conformation, protein-DNA interaction, and even transcription. HDACs are also post-transcriptional modifiers that regulate the protein acetylation implicated in several pathophysiologic states. HDAC inhibitors have been highlighted as a novel category of anti-cancer drugs. To date, four HDAC inhibitors, Vorinostat, Romidepsin, Panobinostat, and Belinostat, have been approved by the United States Food and Drug Administration. Principally, these HDAC inhibitors are used for hematologic cancers in clinic with less severe side effects. Clinical trials are continuously expanding to address other types of cancer and also nonmalignant diseases. HDAC inhibition also results in beneficial outcomes in various types of neurodegenerative diseases, inflammation disorders, and cardiovascular diseases. In this review, we will briefly discuss 1) the roles of HDACs in the acquisition of a cancer's phenotype and the general outcome of the HDAC inhibitors in cancer, 2) the functional relevance of HDACs in cardiovascular diseases and the possible therapeutic implications of HDAC inhibitors in cardiovascular disease. PMID:26865995

Resveratrol as a Pan-HDAC Inhibitor Alters the Acetylation Status of Jistone Proteins in Human-Derived Hepatoblastoma Cells

PubMed Central

Böcker, Alexander; Busch, Christian; Weiland, Timo; Noor, Seema; Leischner, Christian; Schleicher, Sabine; Mayer, Mascha; Weiss, Thomas S.; Bischoff, Stephan C.; Lauer, Ulrich M.; Bitzer, Michael

2013-01-01

The polyphenolic alcohol resveratrol has demonstrated promising activities for the prevention and treatment of cancer. Different modes of action have been described for resveratrol including the activation of sirtuins, which represent the class III histone deacetylases (HDACs). However, little is known about the activity of resveratrol on the classical HDACs of class I, II and IV, although these classes are involved in cancer development or progression and inhibitors of HDACs (HDACi) are currently under investigation as promising novel anticancer drugs. We could show by in silico docking studies that resveratrol has the chemical structure to inhibit the activity of different human HDAC enzymes. In vitro analyses of overall HDAC inhibition and a detailed HDAC profiling showed that resveratrol inhibited all eleven human HDACs of class I, II and IV in a dose-dependent manner. Transferring this molecular mechanism into cancer therapy strategies, resveratrol treatment was analyzed on solid tumor cell lines. Despite the fact that hepatocellular carcinoma (HCC) is known to be particularly resistant against conventional chemotherapeutics, treatment of HCC with established HDACi already has shown promising results. Testing of resveratrol on hepatoma cell lines HepG2, Hep3B and HuH7 revealed a dose-dependent antiproliferative effect on all cell lines. Interestingly, only for HepG2 cells a specific inhibition of HDACs and in turn a histone hyperacetylation caused by resveratrol was detected. Additional testing of human blood samples demonstrated a HDACi activity by resveratrol ex vivo. Concluding toxicity studies showed that primary human hepatocytes tolerated resveratrol, whereas in vivo chicken embryotoxicity assays demonstrated severe toxicity at high concentrations. Taken together, this novel pan-HDACi activity opens up a new perspective of resveratrol for cancer therapy alone or in combination with other chemotherapeutics. Moreover, resveratrol may serve as a lead structure for chemical optimization of bioavailability, pharmacology or HDAC inhibition. PMID:24023672

Runx2- and histone deacetylase 3-mediated repression is relieved in differentiating human osteoblast cells to allow high bone sialoprotein expression.

PubMed

Lamour, Virginie; Detry, Cédric; Sanchez, Christelle; Henrotin, Yves; Castronovo, Vincent; Bellahcène, Akeila

2007-12-14

Bone sialoprotein (BSP) is a bone matrix glycoprotein whose expression coincides with terminal osteoblastic differentiation and the onset of mineralization. In this study we show that BSP expression is considerably increased in confluent Saos-2 human osteosarcoma cells and in differentiating normal human osteoblasts, concomitantly with the decrease of Runx2, a key transcription factor controlling bone formation. Therefore, we investigated the role of Runx2 in the regulation of BSP expression in Saos-2 cells. Using a mobility shift assay, we demonstrated that Runx2 binds to the BSP promoter only in preconfluent cells. Histone deacetylase 3 (HDAC3) has been recently shown to act as a Runx2 co-repressor. Chromatin immunoprecipitation assays demonstrated that both Runx2 and HDAC3 are detectable at the BSP promoter in preconfluent Saos-2 cells but not when they are confluent and overexpress BSP. Consistently, nuclear Runx2 protein level is down-regulated, whereas Saos-2 cells became increasingly confluent. Finally, the suppression of HDAC3, Runx2, or both by RNA interference induced the expression of BSP at both mRNA and protein levels in Saos-2 cells. Our data demonstrate that Runx2 and HDAC3 repress BSP gene expression and that this repression is suspended upon osteoblastic cell differentiation. Both the nuclear disappearance of Runx2 and the non-recruitment of HDAC3 represent new means to relieve Runx2-mediated suppression of BSP expression, thus allowing the acquisition of a fully differentiated and mineralization-competent phenotype by osteoblast cells.

HDAC4 and HDAC6 sustain DNA double strand break repair and stem-like phenotype by promoting radioresistance in glioblastoma cells.

PubMed

Marampon, Francesco; Megiorni, Francesca; Camero, Simona; Crescioli, Clara; McDowell, Heather P; Sferra, Roberta; Vetuschi, Antonella; Pompili, Simona; Ventura, Luca; De Felice, Francesca; Tombolini, Vincenzo; Dominici, Carlo; Maggio, Roberto; Festuccia, Claudio; Gravina, Giovanni Luca

2017-07-01

The role of histone deacetylase (HDAC) 4 and 6 in glioblastoma (GBM) radioresistance was investigated. We found that tumor samples from 31 GBM patients, who underwent temozolomide and radiotherapy combined treatment, showed HDAC4 and HDAC6 expression in 93.5% and 96.7% of cases, respectively. Retrospective clinical data analysis demonstrated that high-intensity HDAC4 and/or HDAC6 immunostaining was predictive of poor clinical outcome. In vitro experiments revealed that short hairpin RNA-mediated silencing of HDAC4 or HDAC6 radiosensitized U87MG and U251MG GBM cell lines by promoting DNA double-strand break (DSBs) accumulation and by affecting DSBs repair molecular machinery. We found that HDAC6 knock-down predisposes to radiation therapy-induced U251MG apoptosis- and U87MG autophagy-mediated cell death. HDAC4 silencing promoted radiation therapy-induced senescence, independently by the cellular context. Finally, we showed that p53 WT expression contributed to the radiotherapy lethal effects and that HDAC4 or HDAC6 sustained GBM stem-like radioresistant phenotype. Altogether, these observations suggest that HDAC4 and HDAC6 are guardians of irradiation-induced DNA damages and stemness, thus promoting radioresistance, and may represent potential prognostic markers and therapeutic targets in GBM. Copyright © 2017 Elsevier B.V. All rights reserved.

Cardiac HDAC6 Catalytic Activity is Induced in Response to Chronic Hypertension

PubMed Central

Lemon, Douglas D.; Horn, Todd R.; Cavasin, Maria A.; Jeong, Mark Y.; Haubold, Kurt W.; Long, Carlin S.; Irwin, David C.; McCune, Sylvia A.; Chung, Eunhee; Leinwand, Leslie A.; McKinsey, Timothy A.

2011-01-01

Small molecule histone deacetylase (HDAC) inhibitors block adverse cardiac remodeling in animal models of heart failure. The efficacious compounds target class I, class IIb and, to a lesser extent, class IIa HDACs. It is hypothesized that a selective inhibitor of a specific HDAC class (or an isoform within that class) will provide a favorable therapeutic window for the treatment of heart failure, although the optimal selectivity profile for such a compound remains unknown. Genetic studies have suggested that class I HDACs promote pathological cardiac remodeling, while class IIa HDACs are protective. In contrast, nothing is known about the function or regulation of class IIb HDACs in the heart. We developed assays to quantify catalytic activity of distinct HDAC classes in left and right ventricular cardiac tissue from animal models of hypertensive heart disease. Class I and IIa HDAC activity was elevated in some but not all diseased tissues. In contrast, catalytic activity of the class IIb HDAC, HDAC6, was consistently increased in stressed myocardium, but not in a model of physiologic hypertrophy. HDAC6 catalytic activity was also induced by diverse extracellular stimuli in cultured cardiac myocytes and fibroblasts. These findings suggest an unforeseen role for HDAC6 in the heart, and highlight the need for pre-clinical evaluation of HDAC6-selective inhibitors to determine whether this HDAC isoform is pathological or protective in the setting of cardiovascular disease. PMID:21539845

Mechanisms of Acquired Drug Resistance to the HDAC6 Selective Inhibitor Ricolinostat Reveals Rational Drug-Drug Combination with Ibrutinib.

PubMed

Amengual, Jennifer E; Prabhu, Sathyen A; Lombardo, Maximilian; Zullo, Kelly; Johannet, Paul M; Gonzalez, Yulissa; Scotto, Luigi; Serrano, Xavier Jirau; Wei, Ying; Duong, Jimmy; Nandakumar, Renu; Cremers, Serge; Verma, Akanksha; Elemento, Olivier; O'Connor, Owen A

2017-06-15

Purpose: Pan-class I/II histone deacetylase (HDAC) inhibitors are effective treatments for select lymphomas. Isoform-selective HDAC inhibitors are emerging as potentially more targeted agents. ACY-1215 (ricolinostat) is a first-in-class selective HDAC6 inhibitor. To better understand the discrete function of HDAC6 and its role in lymphoma, we developed a lymphoma cell line resistant to ACY-1215. Experimental Design: The diffuse large B-cell lymphoma cell line OCI-Ly10 was exposed to increasing concentrations of ACY-1215 over an extended period of time, leading to the development of a resistant cell line. Gene expression profiling (GEP) was performed to investigate differentially expressed genes. Combination studies of ACY-1215 and ibrutinib were performed in cell lines, primary human lymphoma tissue, and a xenograft mouse model. Results: Systematic incremental increases in drug exposure led to the development of distinct resistant cell lines with IC 50 values 10- to 20-fold greater than that for parental lines. GEP revealed upregulation of MAPK10, HELIOS, HDAC9, and FYN, as well as downregulation of SH3BP5 and LCK. Gene-set enrichment analysis (GSEA) revealed modulation of the BTK pathway. Ibrutinib was found to be synergistic with ACY-1215 in cell lines as well as in 3 primary patient samples of lymphoma. In vivo confirmation of antitumor synergy was demonstrated with a xenograft of DLBCL. Conclusions: The development of this ACY-1215-resistant cell line has provided valuable insights into the mechanistic role of HDAC6 in lymphoma and offered a novel method to identify rational synergistic drug combinations. Translation of these findings to the clinic is underway. Clin Cancer Res; 23(12); 3084-96. ©2016 AACR . ©2016 American Association for Cancer Research.

In Silico Investigation of Traditional Chinese Medicine Compounds to Inhibit Human Histone Deacetylase 2 for Patients with Alzheimer's Disease

PubMed Central

Hung, Tzu-Chieh; Lee, Wen-Yuan; Chen, Kuen-Bao; Chan, Yueh-Chiu; Lee, Cheng-Chun

2014-01-01

Human histone deacetylase 2 (HDAC2) has been identified as being associated with Alzheimer's disease (AD), a neuropathic degenerative disease. In this study, we screen the world's largest Traditional Chinese Medicine (TCM) database for natural compounds that may be useful as lead compounds in the search for inhibitors of HDAC2 function. The technique of molecular docking was employed to select the ten top TCM candidates. We used three prediction models, multiple linear regression (MLR), support vector machine (SVM), and the Bayes network toolbox (BNT), to predict the bioactivity of the TCM candidates. Molecular dynamics simulation provides the protein-ligand interactions of compounds. The bioactivity predictions of pIC50 values suggest that the TCM candidatesm, (−)-Bontl ferulate, monomethylcurcumin, and ningposides C, have a greater effect on HDAC2 inhibition. The structure variation caused by the hydrogen bonds and hydrophobic interactions between protein-ligand interactions indicates that these compounds have an inhibitory effect on the protein. PMID:25045700

The multifaceted influence of histone deacetylases on DNA damage signalling and DNA repair

PubMed Central

Roos, Wynand Paul; Krumm, Andrea

2016-01-01

Histone/protein deacetylases play multiple roles in regulating gene expression and protein activation and stability. Their deregulation during cancer initiation and progression cause resistance to therapy. Here, we review the role of histone deacetylases (HDACs) and the NAD+ dependent sirtuins (SIRTs) in the DNA damage response (DDR). These lysine deacetylases contribute to DNA repair by base excision repair (BER), nucleotide excision repair (NER), mismatch repair (MMR), non-homologous end joining (NHEJ), homologous recombination (HR) and interstrand crosslink (ICL) repair. Furthermore, we discuss possible mechanisms whereby these histone/protein deacetylases facilitate the switch between DNA double-strand break (DSB) repair pathways, how SIRTs play a central role in the crosstalk between DNA repair and cell death pathways due to their dependence on NAD+, and the influence of small molecule HDAC inhibitors (HDACi) on cancer cell resistance to genotoxin based therapies. Throughout the review, we endeavor to identify the specific HDAC targeted by HDACi leading to therapy sensitization. PMID:27738139

Vorinostat, a histone deacetylase (HDAC) inhibitor, promotes cell cycle arrest and re-sensitizes rituximab- and chemo-resistant lymphoma cells to chemotherapy agents.

PubMed

Xue, Kai; Gu, Juan J; Zhang, Qunling; Mavis, Cory; Hernandez-Ilizaliturri, Francisco J; Czuczman, Myron S; Guo, Ye

2016-02-01

Preclinical models of chemotherapy resistance and clinical observations derived from the prospective multicenter phase III collaborative trial in relapsed aggressive lymphoma (CORAL) study demonstrated that primary refractory/relapsed B cell diffuse large B cell lymphoma has a poor clinical outcome with current available second-line treatments. Preclinically, we found that rituximab resistance is associated with a deregulation on the mitochondrial potential rendering lymphoma cells resistant to chemotherapy-induced apoptotic stimuli. There is a dire need to develop agents capable to execute alternative pathways of cell death in an attempt to overcome chemotherapy resistance. Posttranscriptional histone modification plays an important role in regulating gene transcription and is altered by histone acetyltransferases (HATs) and histone deacetylases (HDACs). HDACs regulate several key cellular functions, including cell proliferation, cell cycle, apoptosis, angiogenesis, migration, antigen presentation, and/or immune regulation. Given their influence in multiple regulatory pathways, HDAC inhibition is an attractive strategy to evaluate its anti-proliferation activity in cancer cells. To this end, we studied the anti-proliferation activity and mechanisms of action of suberoylanilide hydroxamic acid (SAHA, vorinostat) in rituximab-chemotherapy-resistant preclinical models. A panel of rituximab-chemotherapy-sensitive (RSCL) and rituximab-chemotherapy-resistant cell lines (RRCL) and primary tumor cells isolated from relapsed/refractory B cell lymphoma patients were exposed to escalating doses of vorinostat. Changes in mitochondrial potential, ATP synthesis, and cell cycle distribution were determined by Alamar blue reduction, Titer-Glo luminescent assays, and flow cytometric, respectively. Protein lysates were isolated from vorinostat-exposed cells, and changes in members of Bcl-2 family, cell cycle regulatory proteins, and the acetylation status of histone H3 were evaluated by Western blotting. Finally, cell lines were pre-exposed to vorinostat for 48 h and subsequently exposed to several chemotherapy agents (cisplatin, etoposide, or gemcitabine); changes in cell viability were determined by CellTiter-Glo(®) luminescence assay (Promega, Fitchburg, WI), and synergistic activity was evaluated using the CalcuSyn software. Vorinostat induced dose-dependent cell death in RRCL and in primary tumor cells. In addition, in vitro exposure of RRCL to vorinostat resulted in an increase in p21 and acetylation of histone H3 leading to G1 cell cycle arrest. Vorinostat exposure resulted in apoptosis in RSCL cell lines but not in RRCL. This finding suggests that in RRCL, vorinostat induces cell death by alternative pathways (i.e., irreversible cell cycle arrest). Of interest, vorinostat was found to reverse acquired chemotherapy resistance in RRCL. Our data suggest that vorinostat is active in RRCL with a known defective apoptotic machinery, it can active alternative cell death pathways. Given the multiple pathways affected by HDAC inhibition, vorinostat can potentially be used to overcome acquired resistant to chemotherapy in aggressive B cell lymphoma.

Human HDAC7 Harbors a Class IIa Histone Deacetylase-specific Zinc Binding Motif and Cryptic Deacetylase Activity*S⃞

PubMed Central

Schuetz, Anja; Min, Jinrong; Allali-Hassani, Abdellah; Schapira, Matthieu; Shuen, Michael; Loppnau, Peter; Mazitschek, Ralph; Kwiatkowski, Nick P.; Lewis, Timothy A.; Maglathin, Rebecca L.; McLean, Thomas H.; Bochkarev, Alexey; Plotnikov, Alexander N.; Vedadi, Masoud; Arrowsmith, Cheryl H.

2008-01-01

Histone deacetylases (HDACs) are protein deacetylases that play a role in repression of gene transcription and are emerging targets in cancer therapy. Here, we characterize the structure and enzymatic activity of the catalytic domain of human HDAC7 (cdHDAC7). Although HDAC7 normally exists as part of a multiprotein complex, we show that cdHDAC7 has a low level of deacetylase activity which can be inhibited by known HDAC inhibitors. The crystal structures of human cdHDAC7 and its complexes with two hydroxamate inhibitors are the first structures of the catalytic domain of class IIa HDACs and demonstrate significant differences with previously reported class I and class IIb-like HDAC structures. We show that cdHDAC7 has an additional class IIa HDAC-specific zinc binding motif adjacent to the active site which is likely to participate in substrate recognition and protein-protein interaction and may provide a site for modulation of activity. Furthermore, a different active site topology results in modified catalytic properties and in an enlarged active site pocket. Our studies provide mechanistic insights into class IIa HDACs and facilitate the design of specific modulators. PMID:18285338

Human HDAC7 harbors a class IIa histone deacetylase-specific zinc binding motif and cryptic deacetylase activity.

PubMed

Schuetz, Anja; Min, Jinrong; Allali-Hassani, Abdellah; Schapira, Matthieu; Shuen, Michael; Loppnau, Peter; Mazitschek, Ralph; Kwiatkowski, Nick P; Lewis, Timothy A; Maglathin, Rebecca L; McLean, Thomas H; Bochkarev, Alexey; Plotnikov, Alexander N; Vedadi, Masoud; Arrowsmith, Cheryl H

2008-04-25

Histone deacetylases (HDACs) are protein deacetylases that play a role in repression of gene transcription and are emerging targets in cancer therapy. Here, we characterize the structure and enzymatic activity of the catalytic domain of human HDAC7 (cdHDAC7). Although HDAC7 normally exists as part of a multiprotein complex, we show that cdHDAC7 has a low level of deacetylase activity which can be inhibited by known HDAC inhibitors. The crystal structures of human cdHDAC7 and its complexes with two hydroxamate inhibitors are the first structures of the catalytic domain of class IIa HDACs and demonstrate significant differences with previously reported class I and class IIb-like HDAC structures. We show that cdHDAC7 has an additional class IIa HDAC-specific zinc binding motif adjacent to the active site which is likely to participate in substrate recognition and protein-protein interaction and may provide a site for modulation of activity. Furthermore, a different active site topology results in modified catalytic properties and in an enlarged active site pocket. Our studies provide mechanistic insights into class IIa HDACs and facilitate the design of specific modulators.

Lacosamide reduces HDAC levels in the brain and improves memory: Potential for treatment of Alzheimer's disease.

PubMed

Bang, Shraddha R; Ambavade, Shirishkumar D; Jagdale, Priti G; Adkar, Prafulla P; Waghmare, Arun B; Ambavade, Prashant D

2015-07-01

Lacosamide, a histone deacetylase (HDAC) inhibitor, has been approved for the treatment of epilepsy. Some HDAC inhibitors have been proven effective for the treatment of memory disorders. The present investigation was designed to evaluate the effect of lacosamide on memory and brain HDAC levels. The effect on memory was evaluated in animals with scopolamine-induced amnesia using the elevated plus maze, object recognition test, and radial arm maze. The levels of acetylcholinesterase and HDAC in the cerebral cortex were evaluated. Lacosamide at doses of 10 and 30mg/kg significantly reduced the transfer latency in the elevated plus maze. Lacosamide at a dose of 30mg/kg significantly increased the time spent with a familiar object in the object recognition test at the 24h interval and decreased the time spent in the baited arm. Moreover, at this dose, the number of errors in the radial arm maze at 3 and 24h intervals was minimized and a reduction in the level of HDAC1, but not acetylcholinesterase, was observed in the cerebral cortex. These effects of lacosamide are equivalent to those of piracetam at a dose of 300mg/kg. These results suggest that lacosamide at a 30mg/kg dose improves disrupted memory, possibly by inhibiting HDAC, and could be used to treat amnesic symptoms of Alzheimer's disease. Copyright © 2015 Elsevier Inc. All rights reserved.

Benzodiazepine Scaffold as Drug-like Molecular Simplification of FR235222: A Chemical Tool for Exploring HDAC Inhibition.

PubMed

Randino, Rosario; Moronese, Ilaria; Cini, Elena; Bizzarro, Valentina; Persico, Marco; Grimaldi, Manuela; Scrima, Mario; D'Ursi, Anna Maria; Novellino, Ettore; Sobarzo-Sanchez, Eduardo; Rastrelli, Luca; Fattorusso, Caterina; Petrella, Antonello; Rodriquez, Manuela; Taddei, Maurizio

2017-01-01

Synthesis, computational study and biological evaluation of peptidomimetic analogues of FR235222 (3), a natural immunosuppressant and HDAC inhibitor, have been reported. These new compounds, bearing α-hydroxyketone moiety, as more stable zinc binding group (ZBG), were evaluated in vitro as HDAC inhibitors against the human HDACs isoforms 1-9 and in cellular antiproliferative assays on U937 human leukemia cell line. The 1,4-benzodiazepin-2,5-dione (BDZ), capping group and the natural ZBG, (S,R)-2-amino-9-hydroxy-8-oxodecanoic acid (Ahoda), were evaluated in order to probe HDAC inhibition and/or paralogue selectivity. Some of the new derivatives showed an interesting activity against a number of HDAC isozymes. The observed activity profile was rationalized by a computational assisted SAR study, in order to understand how the BDZ classes interact with the enzyme into the catalytic pocket. Despite its poor solubility, compound 17b showed significant antiproliferative profile and HDAC inhibition activity. In order to assess how the solubility issue could have affected the biological outcome, bioassay conditions were reproduced and quantification of precipitated particulate material was evaluated by turbidimetric and NMR studies together with physicochemical descriptors prediction. Thus, BDZ 17b has been chosen to be promising lead compounds for further optimization, in order to elucidate molecule- enzyme surface recognition.

Suppression of Class I and II Histone Deacetylases Blunts Pressure-Overload Cardiac Hypertrophy

PubMed Central

Kong, Yongli; Tannous, Paul; Lu, Guangrong; Berenji, Kambeez; Rothermel, Beverly A.; Olson, Eric N.; Hill, Joseph A.

2014-01-01

Background Recent work has demonstrated the importance of chromatin remodeling, especially histone acetylation, in the control of gene expression in the heart. In cell culture models of cardiac hypertrophy, pharmacological suppression of histone deacetylases (HDACs) can either blunt or amplify cell growth. Thus, HDAC inhibitors hold promise as potential therapeutic agents in hypertrophic heart disease. Methods and Results In the present investigation, we studied 2 broad-spectrum HDAC inhibitors in a physiologically relevant banding model of hypertrophy, observing dose-responsive suppression of ventricular growth that was well tolerated in terms of both clinical outcome and cardiac performance measures. In both short-term (3-week) and long-term (9-week) trials, cardiomyocyte growth was blocked by HDAC inhibition, with no evidence of cell death or apoptosis. Fibrotic change was diminished in hearts treated with HDAC inhibitors, and collagen synthesis in isolated cardiac fibroblasts was blocked. Preservation of systolic function in the setting of blunted hypertrophic growth was documented by echocardiography and by invasive pressure measurements. The hypertrophy-associated switch of adult and fetal isoforms of myosin heavy chain expression was attenuated, which likely contributed to the observed preservation of systolic function in HDAC inhibitor–treated hearts. Conclusions Together, these data suggest that HDAC inhibition is a viable therapeutic strategy that holds promise in the treatment of load-induced heart disease. PMID:16735673

Explorative study on isoform-selective histone deacetylase inhibitors.

PubMed

Suzuki, Takayoshi

2009-09-01

Histone deacetylases (HDACs) catalyze the deacetylation of the acetylated lysine residues of histones and non-histone proteins, and are involved in various fundamental life phenomena, such as gene expression and cell cycle progression. Thus far, eighteen HDAC family members (HDAC1-11 and SIRT1-7) have been identified, but the functions of the HDAC isoforms are not yet fully understood. In addition, some of the HDAC isoforms have been suggested to be associated with various disease states, including cancer and neurodegenerative disorders. Therefore, isoform-selective HDAC inhibitors are of great interest, not only as tools for probing the biological functions of the isoforms, but also as candidate therapeutic agents with few side effects. It was against this background that we initiated research programs to identify isoform-selective HDAC inhibitors. We designed HDAC inhibitors based on the three-dimensional structure of the enzyme and on the proposed catalytic mechanism of HDACs, and found several isoform-selective HDAC inhibitors. Furthermore, we elucidated the functions of HDAC6 by chemical genetic approaches using these inhibitors. The results of this research also suggested the feasibility of using isoform-selective HDAC inhibitors as therapeutic agents.

Emerin and histone deacetylase 3 (HDAC3) cooperatively regulate expression and nuclear positions of MyoD, Myf5, and Pax7 genes during myogenesis

PubMed Central

Demmerle, Justin; Koch, Adam J.; Holaska, James M.

2016-01-01

The spatial organization of chromatin is critical in establishing cell-type dependent gene expression programs. The inner nuclear membrane protein emerin has been implicated in regulating global chromatin architecture. We show emerin associates with genomic loci of muscle differentiation promoting factors in murine myogenic progenitors, including Myf5 and MyoD. Prior to their transcriptional activation Myf5 and MyoD loci localized to the nuclear lamina in proliferating progenitors and moved to the nucleoplasm upon transcriptional activation during differentiation. The Pax7 locus, which is transcribed in proliferating progenitors, localized to the nucleoplasm and Pax7 moved to the nuclear lamina upon repression during differentiation. Localization of Myf5, MyoD, and Pax7 to the nuclear lamina and proper temporal expression of these genes required emerin and HDAC3. Interestingly, activation of HDAC3 catalytic activity rescued both Myf5 localization to the nuclear lamina and its expression. Collectively, these data support a model whereby emerin facilitates repressive chromatin formation at the nuclear lamina by activating the catalytic activity of HDAC3 to regulate the coordinated spatiotemporal expression of myogenic differentiation genes. PMID:24062260

LTR12 promoter activation in a broad range of human tumor cells by HDAC inhibition

PubMed Central

Krönung, Sonja K.; Beyer, Ulrike; Chiaramonte, Maria Luisa; Dolfini, Diletta; Mantovani, Roberto; Dobbelstein, Matthias

2016-01-01

A considerable proportion of the human genome consists of transposable elements, including the long terminal repeats (LTRs) of endogenous retroviruses. During evolution, such LTRs were occasionally inserted upstream of protein-coding genes, contributing to their regulation. We previously identified the LTR12 from endogenous retrovirus 9 (ERV9) as a regulator of proapoptotic genes such as TP63 or TNFRSF10B. The promoter activity of LTR12 is largely confined to the testes, silenced in testicular carcinoma, but reactivated in testicular cancer cells by broad-range histone deacetylase (HDAC) inhibitors. Here we show that inhibition of HDAC1-3 is sufficient for LTR12 activation. Importantly, HDAC inhibitors induce LTR12 activity not only in testicular cancer cells, but also in cells derived from many additional tumor species. Finally, we characterize the transcription factor NF-Y as a mediator of LTR12 promoter activity and HDAC inhibitor-induced apoptosis, in the context of widespread genomic binding of NF-Y to specific LTR12 sequences. Thus, HDAC inhibitor-driven LTR12 activation represents a generally applicable means to induce proapoptotic genes in human cancer cells. PMID:27172897

Repurposing Pan-HDAC Inhibitors for ARID1A-Mutated Ovarian Cancer.

PubMed

Fukumoto, Takeshi; Park, Pyoung Hwa; Wu, Shuai; Fatkhutdinov, Nail; Karakashev, Sergey; Nacarelli, Timothy; Kossenkov, Andrew V; Speicher, David W; Jean, Stephanie; Zhang, Lin; Wang, Tian-Li; Shih, Ie-Ming; Conejo-Garcia, Jose R; Bitler, Benjamin G; Zhang, Rugang

2018-03-27

ARID1A, a subunit of the SWI/SNF complex, is among the most frequently mutated genes across cancer types. ARID1A is mutated in more than 50% of ovarian clear cell carcinomas (OCCCs), diseases that have no effective therapy. Here, we show that ARID1A mutation confers sensitivity to pan-HDAC inhibitors such as SAHA in ovarian cancers. This correlated with enhanced growth suppression induced by the inhibition of HDAC2 activity in ARID1A-mutated cells. HDAC2 interacts with EZH2 in an ARID1A status-dependent manner. HDAC2 functions as a co-repressor of EZH2 to suppress the expression of EZH2/ARID1A target tumor suppressor genes such as PIK3IP1 to inhibit proliferation and promote apoptosis. SAHA reduced the growth and ascites of the ARID1A-inactivated OCCCs in both orthotopic and genetic mouse models. This correlated with a significant improvement of survival of mice bearing ARID1A-mutated OCCCs. These findings provided preclinical rationales for repurposing FDA-approved pan-HDAC inhibitors for treating ARID1A-mutated cancers. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Histone Deacetylases Exert Class-Specific Roles in Conditioning the Brain and Heart Against Acute Ischemic Injury

PubMed Central

Aune, Sverre E.; Herr, Daniel J.; Kutz, Craig J.; Menick, Donald R.

2015-01-01

Ischemia-reperfusion (IR) injury comprises a significant portion of morbidity and mortality from heart and brain diseases worldwide. This enduring clinical problem has inspired myriad reports in the scientific literature of experimental interventions seeking to elucidate the pathology of IR injury. Elective cardiac surgery presents perhaps the most viable scenario for protecting the heart and brain from IR injury due to the opportunity to condition the organs prior to insult. The physiological parameters for the preconditioning of vital organs prior to insult through mechanical and pharmacological maneuvers have been heavily examined. These investigations have revealed new insights into how preconditioning alters cellular responses to IR injury. However, the promise of preconditioning remains unfulfilled at the clinical level, and research seeking to implicate cell signals essential to this protection continues. Recent discoveries in molecular biology have revealed that gene expression can be controlled through posttranslational modifications, without altering the chemical structure of the genetic code. In this scenario, gene expression is repressed by enzymes that cause chromatin compaction through catalytic removal of acetyl moieties from lysine residues on histones. These enzymes, called histone deacetylases (HDACs), can be inhibited pharmacologically, leading to the de-repression of protective genes. The discovery that HDACs can also alter the function of non-histone proteins through posttranslational deacetylation has expanded the potential impact of HDAC inhibitors for the treatment of human disease. HDAC inhibitors have been applied in a very small number of experimental models of IR. However, the scientific literature contains an increasing number of reports demonstrating that HDACs converge on preconditioning signals in the cell. This review will describe the influence of HDACs on major preconditioning signaling pathways in the heart and brain. PMID:26175715

Mutual inhibition between HDAC9 and miR-17 regulates osteogenesis of human periodontal ligament stem cells in inflammatory conditions.

PubMed

Li, Liya; Liu, Wenjia; Wang, Hong; Yang, Qianjuan; Zhang, Liqiang; Jin, Fang; Jin, Yan

2018-04-24

Histone deacetylases (HDAC) plays important roles in the post-translational modifications of histone cores as well as non-histone targets. Many of them are involved in key inflammatory processes. Despite their importance, whether and how HDAC9 is regulated under inflammatory conditions remains unclear. The aim of this study was to evaluate the effects of HDAC9 under chronic inflammation condition in human periodontal ligament stromal cell (PDLSCs) and to explore the underlying regulatory mechanism. PDLSCs from healthy or periodontitis human tissue was compared. The therapeutic effects of HDAC inhibitors was determined in PDLSC pellet transplanted nude mice and LPS-induced rat periodontitis. We report that HDAC9 was the most affected HDAC family member under inflammatory conditions in PDLSCs. HDAC9 impaired osteogenic differentiation capacity of PDLSCs under inflammatory conditions. Downregulation of HDAC9 by HDAC inhibitors or si-HDAC9 rescued the osteogenic differentiation capacity of inflammatory PDLSC to a similar level with the healthy PDLSC. In this context, HDAC9 and miR-17 formed an inhibitory loop. The inhibition of miR-17 aggravated loss of calcified nodules in inflamed PDLSCs and interrupted the effect of HDAC inhibitor in rescuing osteogenesis. In vivo experiments using nude mice and LPS-induced periodontitis model confirmed that HDAC inhibitors could improve new bone formation. We conclude that HDAC inhibitors improved osteogenesis of PDLSCs in vitro and periodontitis in vivo.

Histone Deacetylase Inhibitor Trichostatin A Ameliorated Endotoxin-Induced Neuroinflammation and Cognitive Dysfunction

PubMed Central

Chen, Yeong-Chang; Wei, Tsui-Shan; Sun, Ding-Ping; Wang, Jhi-Joung; Yeh, Ching-Hua

2015-01-01

Excessive production of cytokines by microglia may cause cognitive dysfunction and long-lasting behavioral changes. Activating the peripheral innate immune system stimulates cytokine secretion in the central nervous system, which modulates cognitive function. Histone deacetylases (HDACs) modulate cytokine synthesis and release. Trichostatin A (TSA), an HDAC inhibitor, is documented to be anti-inflammatory and neuroprotective. We investigated whether TSA reduces lipopolysaccharide- (LPS-) induced neuroinflammation and cognitive dysfunction. ICR mice were first intraperitoneally (i.p.) injected with vehicle or TSA (0.3 mg/kg). One hour later, they were injected (i.p.) with saline or Escherichia coli LPS (1 mg/kg). We analyzed the food and water intake, body weight loss, and sucrose preference of the injected mice and then determined the microglia activation and inflammatory cytokine expression in the brains of LPS-treated mice and LPS-treated BV-2 microglial cells. In the TSA-pretreated mice, microglial activation was lower, anhedonia did not occur, and LPS-induced cognitive dysfunction (anorexia, weight loss, and social withdrawal) was attenuated. Moreover, mRNA expression of HDAC2, HDAC5, indoleamine 2,3-dioxygenase (IDO), TNF-α, MCP-1, and IL-1β in the brain of LPS-challenged mice and in the LPS-treated BV-2 microglial cells was lower. TSA diminished LPS-induced inflammatory responses in the mouse brain and modulated the cytokine-associated changes in cognitive function, which might be specifically related to reducing HDAC2 and HDAC5 expression. PMID:26273133

Histone deacetylase 1 and 2 are essential for murine neural crest proliferation, pharyngeal arch development, and craniofacial morphogenesis.

PubMed

Milstone, Zachary J; Lawson, Grace; Trivedi, Chinmay M

2017-12-01

Craniofacial anomalies involve defective pharyngeal arch development and neural crest function. Copy number variation at 1p35, containing histone deacetylase 1 (Hdac1), or 6q21-22, containing Hdac2, are implicated in patients with craniofacial defects, suggesting an important role in guiding neural crest development. However, the roles of Hdac1 and Hdac2 within neural crest cells remain unknown. The neural crest and its derivatives express both Hdac1 and Hdac2 during early murine development. Ablation of Hdac1 and Hdac2 within murine neural crest progenitor cells cause severe hemorrhage, atrophic pharyngeal arches, defective head morphogenesis, and complete embryonic lethality. Embryos lacking Hdac1 and Hdac2 in the neural crest exhibit decreased proliferation and increased apoptosis in both the neural tube and the first pharyngeal arch. Mechanistically, loss of Hdac1 and Hdac2 upregulates cyclin-dependent kinase inhibitors Cdkn1a, Cdkn1b, Cdkn1c, Cdkn2b, Cdkn2c, and Tp53 within the first pharyngeal arch. Our results show that Hdac1 and Hdac2 function redundantly within the neural crest to regulate proliferation and the development of the pharyngeal arches by means of repression of cyclin-dependent kinase inhibitors. Developmental Dynamics 246:1015-1026, 2017. © 2017 Wiley Periodicals, Inc. © 2017 Wiley Periodicals, Inc.

Protein Aggregates Are Recruited to Aggresome by Histone Deacetylase 6 via Unanchored Ubiquitin C Termini*

PubMed Central

Ouyang, Hui; Ali, Yousuf O.; Ravichandran, Mani; Dong, Aiping; Qiu, Wei; MacKenzie, Farrell; Dhe-Paganon, Sirano; Arrowsmith, Cheryl H.; Zhai, R. Grace

2012-01-01

The aggresome pathway is activated when proteasomal clearance of misfolded proteins is hindered. Misfolded polyubiquitinated protein aggregates are recruited and transported to the aggresome via the microtubule network by a protein complex consisting of histone deacetylase 6 (HDAC6) and the dynein motor complex. The current model suggests that HDAC6 recognizes protein aggregates by binding directly to polyubiquitinated proteins. Here, we show that there are substantial amounts of unanchored ubiquitin in protein aggregates with solvent-accessible C termini. The ubiquitin-binding domain (ZnF-UBP) of HDAC6 binds exclusively to the unanchored C-terminal diglycine motif of ubiquitin instead of conjugated polyubiquitin. The unanchored ubiquitin C termini in the aggregates are generated in situ by aggregate-associated deubiquitinase ataxin-3. These results provide structural and mechanistic bases for the role of HDAC6 in aggresome formation and further suggest a novel ubiquitin-mediated signaling pathway, where the exposure of ubiquitin C termini within protein aggregates enables HDAC6 recognition and transport to the aggresome. PMID:22069321

Role of histone deacetylases in gene regulation at nuclear lamina.

PubMed

Milon, Beatrice C; Cheng, Haibo; Tselebrovsky, Mikhail V; Lavrov, Sergei A; Nenasheva, Valentina V; Mikhaleva, Elena A; Shevelyov, Yuri Y; Nurminsky, Dmitry I

2012-01-01

Theoretical models suggest that gene silencing at the nuclear periphery may involve "closing" of chromatin by transcriptional repressors, such as histone deacetylases (HDACs). Here we provide experimental evidence confirming these predictions. Histone acetylation, chromatin compactness, and gene repression in lamina-interacting multigenic chromatin domains were analyzed in Drosophila S2 cells in which B-type lamin, diverse HDACs, and lamina-associated proteins were downregulated by dsRNA. Lamin depletion resulted in decreased compactness of the repressed multigenic domain associated with its detachment from the lamina and enhanced histone acetylation. Our data reveal the major role for HDAC1 in mediating deacetylation, chromatin compaction, and gene silencing in the multigenic domain, and an auxiliary role for HDAC3 that is required for retention of the domain at the lamina. These findings demonstrate the manifold and central involvement of class I HDACs in regulation of lamina-associated genes, illuminating a mechanism by which these enzymes can orchestrate normal and pathological development.

Impact of combined HDAC and mTOR inhibition on adhesion, migration and invasion of prostate cancer cells.

PubMed

Wedel, Steffen; Hudak, Lukasz; Seibel, Jens-Michael; Makarević, Jasmina; Juengel, Eva; Tsaur, Igor; Wiesner, Christoph; Haferkamp, Axel; Blaheta, Roman A

2011-06-01

The concept of molecular tumor targeting might provide new hope in the treatment of advanced prostate cancer. We evaluated metastasis blocking properties of the histone deacetylase (HDAC) inhibitor valproic acid (VPA) and the mammalian target of rapamycin (mTOR) inhibitor RAD001 on prostate cancer cell lines. RAD001 or VPA were applied to PC-3 or LNCaP cells, either separately or in combination. Adhesion to vascular endothelium or to immobilized collagen, fibronectin or laminin was quantified. Migration and invasion were explored by a modified Boyden chamber assay. Integrin α and β subtypes were analyzed by flow cytometry, western blotting and RT-PCR. Effects of drug treatment on integrin related signaling, Akt and p70S6kinase activation, histone H3 and H4 acetylation were also determined. Separate application of RAD001 or VPA distinctly reduced tumor cell adhesion, migration and invasion, accompanied by elevated Akt activation and p70S6kinase de-activation. Integrin subtype expression was altered significantly by both compounds (VPA > RAD001). When both drugs were used in concert additive effects were observed on the migratory and invasive behavior but not on tumor-endothelium and tumor-matrix interaction. Separate mTOR or HDAC inhibition slows processes related to tumor metastasis. The RAD001-VPA combination showed advantage over VPA monotreatment with particular respect to migration and invasion. Ongoing studies are required to assess the relevance of VPA monotherapy versus VPA-RAD001 combination on tumor cell motility.

Developmental exposure to 50 parts-per-billion arsenic influences histone modifications and associated epigenetic machinery in a region- and sex-specific manner in the adult mouse brain

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tyler, Christina R.; Hafez, Alexander K.; Solomon, Elizabeth R.

Epidemiological studies report that arsenic exposure via drinking water adversely impacts cognitive development in children and, in adults, can lead to greater psychiatric disease susceptibility, among other conditions. While it is known that arsenic toxicity has a profound effect on the epigenetic landscape, very few studies have investigated its effects on chromatin architecture in the brain. We have previously demonstrated that exposure to a low level of arsenic (50 ppb) during all three trimesters of fetal/neonatal development induces deficits in adult hippocampal neurogenesis in the dentate gyrus (DG), depressive-like symptoms, and alterations in gene expression in the adult mouse brain.more » As epigenetic processes control these outcomes, here we assess the impact of our developmental arsenic exposure (DAE) paradigm on global histone posttranslational modifications and associated chromatin-modifying proteins in the dentate gyrus and frontal cortex (FC) of adult male and female mice. DAE influenced histone 3 K4 trimethylation with increased levels in the male DG and FC and decreased levels in the female DG (no change in female FC). The histone methyltransferase MLL exhibited a similar sex- and region-specific expression profile as H3K4me3 levels, while histone demethylase KDM5B expression trended in the opposite direction. DAE increased histone 3 K9 acetylation levels in the male DG along with histone acetyltransferase (HAT) expression of GCN5 and decreased H3K9ac levels in the male FC along with decreased HAT expression of GCN5 and PCAF. DAE decreased expression of histone deacetylase enzymes HDAC1 and HDAC2, which were concurrent with increased H3K9ac levels but only in the female DG. Levels of H3 and H3K9me3 were not influenced by DAE in either brain region of either sex. These findings suggest that exposure to a low, environmentally relevant level of arsenic during development leads to long-lasting changes in histone methylation and acetylation in the adult brain due to aberrant expression of epigenetic machinery based on region and sex. - Highlights: • Brain tissue from adult mice with developmental arsenic exposure (DAE) was used. • DAE impacted histone methylation and associated methyltransferases based on sex. • DAE differentially altered histone acetylation based on brain region. • DAE altered HATs in males and HDACs in females. • Epigenetic modifier expression correlated with the associated histone modification.« less

Histone deacetylases play a major role in the transcriptional regulation of the Plasmodium falciparum life cycle.

PubMed

Chaal, Balbir K; Gupta, Archna P; Wastuwidyaningtyas, Brigitta D; Luah, Yen-Hoon; Bozdech, Zbynek

2010-01-22

The apparent paucity of molecular factors of transcriptional control in the genomes of Plasmodium parasites raises many questions about the mechanisms of life cycle regulation in these malaria parasites. Epigenetic regulation has been suggested to play a major role in the stage specific gene expression during the Plasmodium life cycle. To address some of these questions, we analyzed global transcriptional responses of Plasmodium falciparum to a potent inhibitor of histone deacetylase activities (HDAC). The inhibitor apicidin induced profound transcriptional changes in multiple stages of the P. falciparum intraerythrocytic developmental cycle (IDC) that were characterized by rapid activation and repression of a large percentage of the genome. A major component of this response was induction of genes that are otherwise suppressed during that particular stage of the IDC or specific for the exo-erythrocytic stages. In the schizont stage, apicidin induced hyperacetylation of histone lysine residues H3K9, H4K8 and the tetra-acetyl H4 (H4Ac4) and demethylation of H3K4me3. Interestingly, we observed overlapping patterns of chromosomal distributions between H4K8Ac and H3K4me3 and between H3K9Ac and H4Ac4. There was a significant but partial association between the apicidin-induced gene expression and histone modifications, which included a number of stage specific transcription factors. Taken together, inhibition of HDAC activities leads to dramatic de-regulation of the IDC transcriptional cascade, which is a result of both disruption of histone modifications and up-regulation of stage specific transcription factors. These findings suggest an important role of histone modification and chromatin remodeling in transcriptional regulation of the Plasmodium life cycle. This also emphasizes the potential of P. falciparum HDACs as drug targets for malaria chemotherapy.

Sodium phenylbutyrate abrogates African swine fever virus replication by disrupting the virus-induced hypoacetylation status of histone H3K9/K14.

PubMed

Frouco, Gonçalo; Freitas, Ferdinando B; Martins, Carlos; Ferreira, Fernando

2017-10-15

African swine fever virus (ASFV) causes a highly lethal disease in swine for which neither a vaccine nor treatment are available. Recently, a new class of drugs that inhibit histone deacetylases enzymes (HDACs) has received an increasing interest as antiviral agents. Considering studies by others showing that valproic acid, an HDAC inhibitor (HDACi), blocks the replication of enveloped viruses and that ASFV regulates the epigenetic status of the host cell by promoting heterochromatinization and recruitment of class I HDACs to viral cytoplasmic factories, the antiviral activity of four HDACi against ASFV was evaluated in this study. Results showed that the sodium phenylbutyrate fully abrogates the ASFV replication, whereas the valproic acid leads to a significant reduction of viral progeny at 48h post-infection (-73.9%, p=0.046), as the two pan-HDAC inhibitors tested (Trichostatin A: -82.2%, p=0.043; Vorinostat: 73.9%, p=0.043). Further evaluation showed that protective effects of NaPB are dose-dependent, interfering with the expression of late viral genes and reversing the ASFV-induced histone H3 lysine 9 and 14 (H3K9K14) hypoacetylation status, compatible to an open chromatin state and possibly enabling the expression of host genes non-beneficial to infection progression. Additionally, a synergic antiviral effect was detected when NaPB is combined with an ASFV-topoisomerase II poison (Enrofloxacin). Altogether, our results strongly suggest that cellular HDACs are involved in the establishment of ASFV infection and emphasize that further in vivo studies are needed to better understand the antiviral activity of HDAC inhibitors. Copyright © 2017 Elsevier B.V. All rights reserved.

Chiral mercaptoacetamides display enantioselective inhibition of histone deacetylase 6 and exhibit neuroprotection in cortical neuron models of oxidative stress.

PubMed

Kalin, Jay H; Zhang, Hankun; Gaudrel-Grosay, Sophie; Vistoli, Giulio; Kozikowski, Alan P

2012-03-05

Mercaptoacetamide-based ligands have been designed as a new class of histone deacetylase (HDAC) inhibitors for possible use in the treatment of neurodegenerative diseases. The thiol group of these compounds provides a key binding element for interaction with the catalytic zinc ion, and thus differs from the more typically employed hydroxamic acid based zinc binding groups. Herein we disclose the chemistry and biology of some substituted mercaptoacetamides with the intention of increasing HDAC6 isoform selectivity while maintaining potency similar to their hydroxamic acid analogues. The introduction of a stereocenter α to the thiol group was found to have a considerable impact on HDAC inhibitor potency. These new compounds were also profiled for their therapeutic potential in an in vitro model of stress-induced neuronal injury and were found to act as nontoxic neuroprotective agents. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Combined autophagy and HDAC inhibition: a phase I safety, tolerability, pharmacokinetic, and pharmacodynamic analysis of hydroxychloroquine in combination with the HDAC inhibitor vorinostat in patients with advanced solid tumors.

PubMed

Mahalingam, Devalingam; Mita, Monica; Sarantopoulos, John; Wood, Leslie; Amaravadi, Ravi K; Davis, Lisa E; Mita, Alain C; Curiel, Tyler J; Espitia, Claudia M; Nawrocki, Steffan T; Giles, Francis J; Carew, Jennifer S

2014-08-01

We previously reported that inhibition of autophagy significantly augmented the anticancer activity of the histone deacetylase (HDAC) inhibitor vorinostat (VOR) through a cathepsin D-mediated mechanism. We thus conducted a first-in-human study to investigate the safety, preliminary efficacy, pharmacokinetics (PK), and pharmacodynamics (PD) of the combination of the autophagy inhibitor hydroxychloroquine (HCQ) and VOR in patients with advanced solid tumors. Of 27 patients treated in the study, 24 were considered fully evaluable for study assessments and toxicity. Patients were treated orally with escalating doses of HCQ daily (QD) (d 2 to 21 of a 21-d cycle) in combination with 400 mg VOR QD (d one to 21). Treatment-related adverse events (AE) included grade 1 to 2 nausea, diarrhea, fatigue, weight loss, anemia, and elevated creatinine. Grade 3 fatigue and/or myelosuppression were observed in a minority of patients. Fatigue and gastrointestinal AE were dose-limiting toxicities. Six-hundred milligrams HCQ and 400 mg VOR was established as the maximum tolerated dose and recommended phase II regimen. One patient with renal cell carcinoma had a confirmed durable partial response and 2 patients with colorectal cancer had prolonged stable disease. The addition of HCQ did not significantly impact the PK profile of VOR. Treatment-related increases in the expression of CDKN1A and CTSD were more pronounced in tumor biopsies than peripheral blood mononuclear cells. Based on the safety and preliminary efficacy of this combination, additional clinical studies are currently being planned to further investigate autophagy inhibition as a new approach to increase the efficacy of HDAC inhibitors.

Genome-wide STAT3 binding analysis after histone deacetylase inhibition reveals novel target genes in dendritic cells

PubMed Central

Sun, Yaping; Iyer, Matthew; McEachin, Richard; Zhao, Meng; Wu, Yi-Mi; Cao, Xuhong; Oravecz-Wilson, Katherine; Zajac, Cynthia; Mathewson, Nathan; Wu, Shin-Rong Julia; Rossi, Corinne; Toubai, Tomomi; Qin, Zhaohui S.; Chinnaiya, Arul M.; Reddy, Pavan

2016-01-01

STAT3 is a master transcriptional regulator that plays an important role in the induction of both immune activation and immune tolerance in dendritic cells (DCs). The transcriptional targets of STAT3 in promoting DC activation are becoming increasingly understood; however, the mechanisms underpinning its role in causing DC suppression remain largely unknown. To determine the functional gene targets of STAT3, we compared the genome-wide binding of STAT3 using ChIP-seq coupled with gene expression microarrays to determine STAT3-dependent gene regulation in DCs after histone deacetylase (HDAC) inhibition. HDAC inhibition boosted the ability of STAT3 to bind to distinct DNA targets and regulate gene expression. Among the top 500 STAT3 binding sites, the frequency of canonical motifs was significantly higher than that of non-canonical motifs. Functional analysis revealed that after treatment with an HDAC inhibitor, the upregulated STAT3 target genes were those that were primarily the negative regulators of pro-inflammatory cytokines and those in the IL-10 signaling pathway. The downregulated STAT3-dependent targets were those involved in immune effector processes and antigen processing/presentation. The expression and functional relevance of these genes were validated. Specifically, functional studies confirmed that the upregulation of IL-10Ra by STAT3 contributed to the suppressive function of DCs following HDAC inhibition. PMID:27866206

Differential contributions of Caenorhabditis elegans histone deacetylases to huntingtin polyglutamine toxicity.

PubMed

Bates, Emily A; Victor, Martin; Jones, Adriana K; Shi, Yang; Hart, Anne C

2006-03-08

Expansion of a polyglutamine tract in the huntingtin protein causes neuronal degeneration and death in Huntington's disease patients, but the molecular mechanisms underlying polyglutamine-mediated cell death remain unclear. Previous studies suggest that expanded polyglutamine tracts alter transcription by sequestering glutamine rich transcriptional regulatory proteins, thereby perturbing their function. We tested this hypothesis in Caenorhabditis elegans neurons expressing a human huntingtin fragment with an expanded polyglutamine tract (Htn-Q150). Loss of function alleles and RNA interference (RNAi) were used to examine contributions of C. elegans cAMP response element-binding protein (CREB), CREB binding protein (CBP), and histone deacetylases (HDACs) to polyglutamine-induced neurodegeneration. Deletion of CREB (crh-1) or loss of one copy of CBP (cbp-1) enhanced polyglutamine toxicity in C. elegans neurons. Loss of function alleles and RNAi were then used to systematically reduce function of each C. elegans HDAC. Generally, knockdown of individual C. elegans HDACs enhanced Htn-Q150 toxicity, but knockdown of C. elegans hda-3 suppressed toxicity. Neuronal expression of hda-3 restored Htn-Q150 toxicity and suggested that C. elegans HDAC3 (HDA-3) acts within neurons to promote degeneration in response to Htn-Q150. Genetic epistasis experiments suggested that HDA-3 and CRH-1 (C. elegans CREB homolog) directly oppose each other in regulating transcription of genes involved in polyglutamine toxicity. hda-3 loss of function failed to suppress increased neurodegeneration in hda-1/+;Htn-Q150 animals, indicating that HDA-1 and HDA-3 have different targets with opposing effects on polyglutamine toxicity. Our results suggest that polyglutamine expansions perturb transcription of CREB/CBP targets and that specific targeting of HDACs will be useful in reducing associated neurodegeneration.

Butyrate and other short-chain fatty acids increase the rate of lipolysis in 3T3-L1 adipocytes

PubMed Central

Rumberger, John M.; Arch, Jonathan R.S.

2014-01-01

We determined the effect of butyrate and other short-chain fatty acids (SCFA) on rates of lipolysis in 3T3-L1 adipocytes. Prolonged treatment with butyrate (5 mM) increased the rate of lipolysis approximately 2–3-fold. Aminobutyric acid and acetate had little or no effect on lipolysis, however propionate stimulated lipolysis, suggesting that butyrate and propionate act through their shared activity as histone deacetylase (HDAC) inhibitors. Consistent with this, the HDAC inhibitor trichostatin A (1 µM) also stimulated lipolysis to a similar extent as did butyrate. Western blot data suggested that neither mitogen-activated protein kinase (MAPK) activation nor perilipin down-regulation are necessary for SCFA-induced lipolysis. Stimulation of lipolysis with butyrate and trichostatin A was glucose-dependent. Changes in AMP-activated protein kinase (AMPK) phosphorylation mediated by glucose were independent of changes in rates of lipolysis. The glycolytic inhibitor iodoacetate prevented both butyrate- and tumor necrosis factor-alpha-(TNF-α) mediated increases in rates of lipolysis indicating glucose metabolism is required. However, unlike TNF-α– , butyrate-stimulated lipolysis was not associated with increased lactate release or inhibited by activation of pyruvate dehydrogenase (PDH) with dichloroacetate. These data demonstrate an important relationship between lipolytic activity and reported HDAC inhibitory activity of butyrate, other short-chain fatty acids and trichostatin A. Given that HDAC inhibitors are presently being evaluated for the treatment of diabetes and other disorders, more work will be essential to determine if these effects on lipolysis are due to inhibition of HDAC. PMID:25320679

Curcumin Derivative Epigenetically Reactivates Nrf2 Antioxidative Stress Signaling in Mouse Prostate Cancer TRAMP C1 Cells.

PubMed

Li, Wenji; Su, Zheng-Yuan; Guo, Yue; Zhang, Chengyue; Wu, Renyi; Gao, Linbo; Zheng, Xi; Du, Zhi-Yun; Zhang, Kun; Kong, Ah-Ng

2018-02-19

The carcinogenesis of prostate cancer (PCa) in TRAMP model is highly correlated with hypermethylation in the promoter region of Nrf2 and the accompanying reduced transcription of Nrf2 and its regulated detoxifying genes. We aimed to investigate the effects of (3E,5E)-3,5-bis-(3,4,5-trimethoxybenzylidene)-tetrahydro-thiopyran-4-one (F10) and (3E,5E)-3,5-bis-(3,4,5-trimethoxy-benzylidene)-tetrahydropyran-4-one (E10), two synthetic curcumin derivatives, on restoring Nrf2 activity in TRAMP C1 cells. HepG2-C8 cells transfected with an antioxidant-response element (ARE)-luciferase vector were treated with F10, E10, curcumin, and sulforaphane (SFN) to compare their effects on Nrf2-ARE pathways. We performed real-time quantitative PCR and Western blotting to investigate the effects of F10 and E10 on Nrf2, correlated phase II detoxification genes. We also measured expression and activity of DNMTand HDAC enzymes. Enrichment of H3K27me3 on the promoter region of Nrf2 was explored with a chromatin immunoprecipitation (ChIP) assay. Methylation of the CpG region in Nrf2 promoter was doubly examined by bisulfite genomic sequencing (BGS) and methylation DNA immunoprecipitation (MeDIP). Compared with curcumin and SFN, F10 is more potent in activating Nrf2-ARE pathways. Both F10 and E10 enhanced level of Nrf2 and the correlated phase II detoxifying genes. BGS and MeDIP assays indicated that F10 but not E10 hypomethylated the Nrf2 promoter. F10 also downregulated the protein level of DNMT1, DNMT3a, DNMT3b, HDAC1, HDAC4, and HDAC7 and the activity of DNMTs and HDACs. F10 but not E10 effectively reduced the accumulation of H3k27me3 on the promoter of Nrf2. F10 and E10 can activate the Nrf2-ARE pathway and increase the level of Nrf2 and correlated phase II detoxification genes. The reactivation effect on Nrf2 by F10 in TRAMP C1 may come from demethylation, decrease of HDACs, and inhibition of H3k27me3 accumulation.

EMA Review of Panobinostat (Farydak) for the Treatment of Adult Patients with Relapsed and/or Refractory Multiple Myeloma.

PubMed

Tzogani, Kyriaki; van Hennik, Paula; Walsh, Ita; De Graeff, Pieter; Folin, Annika; Sjöberg, Jan; Salmonson, Tomas; Bergh, Jonas; Laane, Edward; Ludwig, Heinz; Gisselbrecht, Christian; Pignatti, Francesco

2018-05-01

On August 28, 2015, a marketing authorization valid through the European Union was issued for panobinostat, in combination with bortezomib and dexamethasone, for the treatment of adult patients with relapsed and/or refractory multiple myeloma who have received at least two prior regimens including bortezomib and an immunomodulatory agent (IMiD).Panobinostat is an orally available histone deacetylase (HDAC) inhibitor that inhibits the enzymatic activity of HDAC proteins at nanomolar concentrations. HDAC proteins catalyze the removal of acetyl groups from the lysine residues of histones and some nonhistone proteins. Inhibition of HDAC activity results in increased acetylation of histone proteins, an epigenetic alteration that results in a relaxing of chromatin, leading to transcriptional activation. The recommended starting dose of panobinostat is 20 mg, taken orally in a cyclical manner for up to 48 weeks.The use of panobinostat in combination with bortezomib and dexamethasone was studied in a randomized, double-blind, placebo-controlled, multicenter phase III study (PANORAMA I) in 768 patients with relapsed or relapsed and refractory multiple myeloma who had received one to three prior lines of therapies. In the subgroup of patients who have received at least two prior regimens including bortezomib and an IMiD, there was a difference of 7.8 months in the progression-free survival in favor of the experimental arm (12.5 months for panobinostat + bortezomib + dexamethasone vs. 4.7 months for placebo + bortezomib + dexamethasone; hazard ratio = 0.47, 95% confidence interal 0.31-0.72; log-rank p value = .0003). The incidence of grade 3-4 adverse events suspected to be related to study drug was 76.9% vs. 51.2%, for the panobinostat and the placebo group, respectively. The most common side effects (grade 3-4) associated with panobinostat included diarrhea (18.9%), fatigue (14.7%), nausea (4.5%), vomiting (5.5%), thrombocytopenia (43.6%), anemia (7.9%), neutropenia (16.5%) and lymphopenia (8.1%).This article summarizes the scientific review of the application leading to regulatory approval in the European Union. The full scientific assessment report and product information, including the Summary of Product Characteristics, are available on the European Medicines Agency website (http://www.ema.europa.eu/ema/index.jsp?curl=pages/includes/medicines/medicines_landing_page.jsp&mid=). Farydak was approved in the European Union in combination with bortezomib and dexamethasone, for the treatment of adult patients with relapsed and/or refractory multiple myeloma who have received at least two prior regimens including bortezomib and an immunomodulatory agent (IMiD). The addition of panobinostat to bortezomib and dexamethasone resulted in a clinically meaningful and statistically significant improvement of progression-free survival compared with bortezomib and dexamethasone, and an additional therapeutic option with a new mechanism of action was considered valuable. Although the toxicity associated with panobinostat combination was significant, at the time of the marketing authorization of panobinostat, it was considered that it was acceptable and that it should be left to the clinician and the patient to decide whether the panobinostat combination is the preferred treatment option or not. © AlphaMed Press 2017.

Effects of alcohol on histone deacetylase 2 (HDAC2) and the neuroprotective role of trichostatin A (TSA).

PubMed

Agudelo, Marisela; Gandhi, Nimisha; Saiyed, Zainulabedin; Pichili, Vijaya; Thangavel, Samikkannu; Khatavkar, Pradnya; Yndart-Arias, Adriana; Nair, Madhavan

2011-08-01

Previous studies have implicated histone deacetylases (HDACs) and HDAC inhibitors (HDIs) such as trichostatin A (TSA) in the regulation of gene expression during drug addiction. Furthermore, an increase in HDAC activity has been linked to neurodegeneration. Alcohol has also been shown to promote abundant generation of reactive oxygen species (ROS) resulting in oxidative stress. TSA inhibits HDACs and has been shown to be neuroprotective in other neurodegenerative disease models. Although HDACs and HDIs have been associated with drug addiction, there is no evidence of the neurodegenerative role of HDAC2 and neuroprotective role of TSA in alcohol addiction. Therefore, we hypothesize that alcohol modulates HDAC2 through mechanisms involving oxidative stress. To test our hypothesis, the human neuronal cell line, SK-N-MC, was treated with different concentrations of ethanol (EtOH); HDAC2 gene and protein expression were assessed at different time points. Pharmacological inhibition of HDAC2 with TSA was evaluated at the gene level using qRT-PCR and at the protein level using Western blot and flow cytometry. ROS production was measured with a fluorescence microplate reader and fluorescence microscopy. Our results showed a dose-dependent increase in HDAC2 expression with EtOH treatment. Additionally, alcohol significantly induced ROS, and pharmacological inhibition of HDAC2 with TSA was shown to be neuroprotective by significantly inhibiting HDAC2 and ROS. These results suggest that EtOH can upregulate HDAC2 through mechanisms involving oxidative stress and HDACs may play an important role in alcohol use disorders (AUDs). Moreover, the use of HDIs may be of therapeutic significance for the treatment of neurodegenerative disorders including AUDs. Copyright © 2011 by the Research Society on Alcoholism.

Recruitment by the Repressor Freud-1 of Histone Deacetylase-Brg1 Chromatin Remodeling Complexes to Strengthen HTR1A Gene Repression.

PubMed

Souslova, Tatiana; Mirédin, Kim; Millar, Anne M; Albert, Paul R

2017-12-01

Five-prime repressor element under dual repression binding protein-1 (Freud-1)/CC2D1A is genetically linked to intellectual disability and implicated in neuronal development. Freud-1 represses the serotonin-1A (5-HT1A) receptor gene HTR1A by histone deacetylase (HDAC)-dependent or HDAC-independent mechanisms in 5-HT1A-negative (e.g., HEK-293) or 5-HT1A-expressing cells (SK-N-SH), respectively. To identify the underlying mechanisms, Freud-1-associated proteins were affinity-purified from HEK-293 nuclear extracts and members of the Brg1/SMARCCA chromatin remodeling and Sin3A-HDAC corepressor complexes were identified. Pull-down assays using recombinant proteins showed that Freud-1 interacts directly with the Brg1 carboxyl-terminal domain; interaction with Brg1 required the carboxyl-terminal of Freud-1. Freud-1 complexes in HEK-293 and SK-N-SH cells differed, with low levels of BAF170/SMARCC2 and BAF57/SMARCE1 in HEK-293 cells and low-undetectable BAF155/SMARCC1, Sin3A, and HDAC1/2 in SK-N-SH cells. Similarly, by quantitative chromatin immunoprecipitation, Brg1-BAF170/57 and Sin3A-HDAC complexes were observed at the HTR1A promoter in HEK-293 cells, whereas in SK-N-SH cells, Sin3A-HDAC proteins were not detected. Quantifying 5-HT1A receptor mRNA levels in cells treated with siRNA to Freud-1, Brg1, or both RNAs addressed the functional role of the Freud-1-Brg1 complex. In HEK-293 cells, 5-HT1A receptor mRNA levels were increased only when both Freud-1 and Brg1 were depleted, but in SK-N-SH cells, depletion of either protein upregulated 5-HT1A receptor RNA. Thus, recruitment by Freud-1 of Brg1, BAF155, and Sin3A-HDAC complexes appears to strengthen repression of the HTR1A gene to prevent its expression inappropriate cell types, while recruitment of the Brg1-BAF170/57 complex is permissive to 5-HT1A receptor expression. Alterations in Freud-1-Brg1 interactions in mutants associated with intellectual disability could impair gene repression leading to altered neuronal development.

Recruitment by the Repressor Freud-1 of Histone Deacetylase-Brg1 Chromatin Remodeling Complexes to Strengthen HTR1A Gene Repression

PubMed Central

Souslova, Tatiana; Mirédin, Kim; Millar, Anne M.

2017-01-01

Five-prime repressor element under dual repression binding protein-1 (Freud-1)/CC2D1A is genetically linked to intellectual disability and implicated in neuronal development. Freud-1 represses the serotonin-1A (5-HT1A) receptor gene HTR1A by histone deacetylase (HDAC)-dependent or HDAC-independent mechanisms in 5-HT1A-negative (e.g., HEK-293) or 5-HT1A-expressing cells (SK-N-SH), respectively. To identify the underlying mechanisms, Freud-1-associated proteins were affinity-purified from HEK-293 nuclear extracts and members of the Brg1/SMARCCA chromatin remodeling and Sin3A-HDAC corepressor complexes were identified. Pull-down assays using recombinant proteins showed that Freud-1 interacts directly with the Brg1 carboxyl-terminal domain; interaction with Brg1 required the carboxyl-terminal of Freud-1. Freud-1 complexes in HEK-293 and SK-N-SH cells differed, with low levels of BAF170/SMARCC2 and BAF57/SMARCE1 in HEK-293 cells and low-undetectable BAF155/SMARCC1, Sin3A, and HDAC1/2 in SK-N-SH cells. Similarly, by quantitative chromatin immuno-precipitation, Brg1-BAF170/57 and Sin3A-HDAC complexes were observed at the HTR1A promoter in HEK-293 cells, whereas in SK-N-SH cells, Sin3A-HDAC proteins were not detected. Quantifying 5-HT1A receptor mRNA levels in cells treated with siRNA to Freud-1, Brg1, or both RNAs addressed the functional role of the Freud-1-Brg1 complex. In HEK-293 cells, 5-HT1A receptor mRNA levels were increased only when both Freud-1 and Brg1 were depleted, but in SK-N-SH cells, depletion of either protein upregulated 5-HT1A receptor RNA. Thus, recruitment by Freud-1 of Brg1, BAF155, and Sin3A-HDAC complexes appears to strengthen repression of the HTR1A gene to prevent its expression inappropriate cell types, while recruitment of the Brg1-BAF170/57 complex is permissive to 5-HT1A receptor expression. Alterations in Freud-1-Brg1 interactions in mutants associated with intellectual disability could impair gene repression leading to altered neuronal development. PMID:27914010

In vivo destabilization of dynamic microtubules by HDAC6-mediated deacetylation

PubMed Central

Matsuyama, Akihisa; Shimazu, Tadahiro; Sumida, Yuko; Saito, Akiko; Yoshimatsu, Yasuhiro; Seigneurin-Berny, Daphné; Osada, Hiroyuki; Komatsu, Yasuhiko; Nishino, Norikazu; Khochbin, Saadi; Horinouchi, Sueharu; Yoshida, Minoru

2002-01-01

Trichostatin A (TSA) inhibits all histone deacetylases (HDACs) of both class I and II, whereas trapoxin (TPX) cannot inhibit HDAC6, a cytoplasmic member of class II HDACs. We took advantage of this differential sensitivity of HDAC6 to TSA and TPX to identify its substrates. Using this approach, α-tubulin was identified as an HDAC6 substrate. HDAC6 deacetylated α-tubulin both in vivo and in vitro. Our investigations suggest that HDAC6 controls the stability of a dynamic pool of microtubules. Indeed, we found that highly acetylated microtubules observed after TSA treatment exhibited delayed drug-induced depolymerization and that HDAC6 overexpression prompted their induced depolymerization. Depolymerized tubulin was rapidly deacetylated in vivo, whereas tubulin acetylation occurred only after polymerization. We therefore suggest that acetylation and deacetylation are coupled to the microtubule turnover and that HDAC6 plays a key regulatory role in the stability of the dynamic microtubules. PMID:12486003

HDAC6–p97/VCP controlled polyubiquitin chain turnover

PubMed Central

Boyault, Cyril; Gilquin, Benoit; Zhang, Yu; Rybin, Vladimir; Garman, Elspeth; Meyer-Klaucke, Wolfram; Matthias, Patrick; Müller, Christoph W; Khochbin, Saadi

2006-01-01

HDAC6 is a unique cytoplasmic deacetylase capable of interacting with ubiquitin. Using a combination of biophysical, biochemical and biological approaches, we have characterized the ubiquitin-binding domain of HDAC6, named ZnF-UBP, and investigated its biological functions. These studies show that the three Zn ion-containing HDAC6 ZnF-UBP domain presents the highest known affinity for ubiquitin monomers and mediates the ability of HDAC6 to negatively control the cellular polyubiquitin chain turnover. We further show that HDAC6-interacting chaperone, p97/VCP, dissociates the HDAC6–ubiquitin complexes and counteracts the ability of HDAC6 to promote the accumulation of polyubiquitinated proteins. We propose that a finely tuned balance of HDAC6 and p97/VCP concentrations determines the fate of ubiquitinated misfolded proteins: p97/VCP would promote protein degradation and ubiquitin turnover, whereas HDAC6 would favour the accumulation of ubiquitinated protein aggregates and inclusion body formation. PMID:16810319

Crystal structure of a eukaryotic zinc-dependent histone deacetylase, human HDAC8, complexed with a hydroxamic acid inhibitor.

PubMed

Vannini, Alessandro; Volpari, Cinzia; Filocamo, Gessica; Casavola, Elena Caroli; Brunetti, Mirko; Renzoni, Debora; Chakravarty, Prasun; Paolini, Chantal; De Francesco, Raffaele; Gallinari, Paola; Steinkühler, Christian; Di Marco, Stefania

2004-10-19

Histone deacetylases (HDACs) are a family of enzymes involved in the regulation of gene expression, DNA repair, and stress response. These processes often are altered in tumors, and HDAC inhibitors have had pronounced antitumor activity with promising results in clinical trials. Here, we report the crystal structure of human HDAC8 in complex with a hydroxamic acid inhibitor. Such a structure of a eukaryotic zinc-dependent HDAC has not be described previously. Similar to bacterial HDAC-like protein, HDAC8 folds in a single alpha/beta domain. The inhibitor and the zinc-binding sites are similar in both proteins. However, significant differences are observed in the length and structure of the loops surrounding the active site, including the presence of two potassium ions in HDAC8 structure, one of which interacts with key catalytic residues. CD data suggest a direct role of potassium in the fold stabilization of HDAC8. Knockdown of HDAC8 by RNA interference inhibits growth of human lung, colon, and cervical cancer cell lines, highlighting the importance of this HDAC subtype for tumor cell proliferation. Our findings open the way for the design and development of selective inhibitors of HDAC8 as possible antitumor agents.

Histone deacetylase inhibitors selectively suppress expression of HDAC7.

PubMed

Dokmanovic, Milos; Perez, Gisela; Xu, Weisheng; Ngo, Lang; Clarke, Cathy; Parmigiani, Raphael B; Marks, Paul A

2007-09-01

There are 18 histone deacetylases (HDAC) generally divided into four classes based on homology to yeast HDACs. HDACs have many protein substrates in addition to histones that are involved in regulation of gene expression, cell proliferation, and cell death. Inhibition of HDACs can cause accumulation of acetylated forms of these proteins, thus altering their function. HDAC inhibitors (HDACi), such as the hydroxamic acid-based vorinostat (suberoylanilide hydroxamic acid), inhibit the zinc-containing classes I, II, and IV, but not the NAD(+)-dependent class III, enzymes. HDACis are a group of novel anticancer agents. Vorinostat is the first HDACi approved for clinical use in the treatment of the cancer cutaneous T-cell lymphoma. Factors affecting expression of HDACs are not well understood. This study focuses on the effect of the HDACi vorinostat on the expression of class I and class II HDACs. We found that vorinostat selectively down-regulates HDAC7 with little or no effect on the expression of other class I or class II HDACs. Fourteen cell lines were examined, including normal, immortalized, genetically transformed, and human cancer-derived cell lines. Down-regulation of HDAC7 by vorinostat is more pronounced in transformed cells sensitive to inhibitor-induced cell death than in normal cells or cancer cells resistant to induced cell death. Modulation of HDAC7 levels by small interfering RNA-mediated knockdown or by HDAC7 overexpression is associated with growth arrest but without detectable changes in acetylation of histones or p21 gene expression. Selective down-regulation of HDAC7 protein may serve as a marker of response of tumors to HDACi.

Hippocampal chromatin-modifying enzymes are pivotal for scopolamine-induced synaptic plasticity gene expression changes and memory impairment.

PubMed

Singh, Padmanabh; Konar, Arpita; Kumar, Ashish; Srivas, Sweta; Thakur, Mahendra K

2015-08-01

The amnesic potential of scopolamine is well manifested through synaptic plasticity gene expression changes and behavioral paradigms of memory impairment. However, the underlying mechanism remains obscure and consequently ideal therapeutic target is lacking. In this context, chromatin-modifying enzymes, which regulate memory gene expression changes, deserve major attention. Therefore, we analyzed the expression of chromatin-modifying enzymes and recovery potential of enzyme modulators in scopolamine-induced amnesia. Scopolamine administration drastically up-regulated DNA methyltransferases (DNMT1) and HDAC2 expression while CREB-binding protein (CBP), DNMT3a and DNMT3b remained unaffected. HDAC inhibitor sodium butyrate and DNMT inhibitor Aza-2'deoxycytidine recovered scopolamine-impaired hippocampal-dependent memory consolidation with concomitant increase in the expression of synaptic plasticity genes Brain-derived neurotrophic factor (BDNF) and Arc and level of histone H3K9 and H3K14 acetylation and decrease in DNA methylation level. Sodium butyrate showed more pronounced effect than Aza-2'deoxycytidine and their co-administration did not exhibit synergistic effect on gene expression. Taken together, we showed for the first time that scopolamine-induced up-regulation of chromatin-modifying enzymes, HDAC2 and DNMT1, leads to gene expression changes and consequent decline in memory consolidation. Our findings on the action of scopolamine as an epigenetic modulator can pave a path for ideal therapeutic targets. We propose the following putative pathway for scopolamine-mediated memory impairment; scopolamine up-regulates hippocampal DNMT1 and HDAC2 expression, induces methylation and deacetylation of BDNF and Arc promoter, represses gene expression and eventually impairs memory consolidation. On the other hand, Aza-2 and NaB inhibit DNMT1 and HDAC2 respectively, up-regulate BDNF and Arc expression and recover memory consolidation. We elucidate the action of scopolamine as an epigenetic modulator and hope that DNMT1 and HDAC2 would be ideal therapeutic targets for memory disorders. © 2015 International Society for Neurochemistry.

Role of histone deacetylases(HDACs) in progression and reversal of liver fibrosis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Li, Xing; Wu, Xiao-Qin; Xu, Tao

Liver fibrosis refers to a reversible wound healing process response to chronic liver injuries. Activation of hepatic stellate cells (HSCs) is closely correlated with the development of liver fibrosis. Histone deacetylases(HDACs) determine the acetylation levels of core histones to modulate expression of genes. To demonstrate the link between HDACs and liver fibrosis, CCl4-induced mouse liver fibrosis model and its spontaneous reversal model were established. Results of the current study demonstrated that deregulation of liver HDACs may involved in the development of liver fibrosis. Among 11 HDACs tested in our study (Class I, II, and IV HDACs), expression of HDAC2 wasmore » maximally increased in CCl4-induced fibrotic livers but decreased after spontaneous recovery. Moreover, expression of HDAC2 was elevated in human liver fibrotic tissues. In this regard, the potential role of HDAC2 in liver fibrosis was further evaluated. Our results showed that administration of HSC-T6 cells with transforming growth factor-beta1 (TGF-β1) resulted in an increase of HDAC2 protein expression in dose- and time-dependent manners. Moreover, HDAC2 deficiency inhibited HSC-T6 cell proliferation and activation induced by TGF-β1. More importantly, the present study showed HDAC2 may regulate HSCs activation by suppressing expression of Smad7, which is a negative modulator in HSCs activation and liver fibrosis. Collectively, these observations revealed that HDAC2 may play a pivotal role in HSCs activation and liver fibrosis while deregulation of HDACs may serve as a novel mechanism underlying liver fibrosis. - Highlights: • This is the first report to systematically examine expressions of HDACs during liver fibrosis and fibrosis reversal. • Aberrant expression of HDAC2 contributes to the development of liver fibrosis. • Provided important foundation for further liver fibrosis conversion studies.« less

Inhibition of monomethylarsonous acid (MMA(III))-induced cell malignant transformation through restoring dysregulated histone acetylation.

PubMed

Ge, Yichen; Gong, Zhihong; Olson, James R; Xu, Peilin; Buck, Michael J; Ren, Xuefeng

2013-10-04

Inorganic arsenic (iAs) and its high toxic metabolite, monomethylarsonous acid (MMA(III)), are able to induce malignant transformation of human cells. Chronic exposure to these chemicals is associated with an increased risk of developing multiple cancers in human. However, the mechanisms contributing to iAs/MMA(III)-induced cell malignant transformation and carcinogenesis are not fully elucidated. We recently showed that iAs/MMA(III) exposure to human cells led to a decreased level of histone acetylation globally, which was associated with an increased sensitivity to arsenic cytotoxicity. In the current study, it demonstrated that prolonged exposure to low-level MMA(III) in human urothelial cells significantly increased the expression and activity of histone deacetylases (HDACs) with an associated reduction of histone acetylation levels both globally and lysine specifically. Administration of the HDAC inhibitor, suberoylanilide hydroxamic acid (SAHA), at 4 weeks after the initial MMA(III) treatment inhibited the MMA(III)-mediated up-regulation of the expression and activities of HDACs, leading to increase histone acetylation and prevention of MMA(III)-induced malignant transformation. These new findings suggest that histone acetylation dysregulation may be a key mechanism in MMA(III)-induced malignant transformation and carcinogenesis, and that HDAC inhibitors could be targeted to prevent or treat iAs-related cancers. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Recent advances in the discovery of potent and selective HDAC6 inhibitors.

PubMed

Wang, Xiu-Xiu; Wan, Ren-Zhong; Liu, Zhao-Peng

2018-01-01

Histone deacetylase HDAC6, a member of the class IIb HDAC family, is unique among HDAC enzymes in having two active catalytic domains, and has unique physiological function. In addition to the modification of histone, HDAC6 targets specific substrates including α-tubulin and HSP90, and are involved in protein trafficking and degradation, cell shape and migration. Selective HDAC6 inhibitors are an emerging class of pharmaceuticals due to the involvement of HDAC6 in different pathways related to neurodegenerative diseases, cancer, and immunology. Therefore, extensive investigations have been made in the discovery of selective HDAC6 inhibitors. Based on their different zinc binding groups (ZBGs), in this review, HDAC6 inhibitors are grouped as hydroxamic acids, a sulfur containing ZBG based derivatives and other ZBG-derived compounds, and their enzymatic inhibitory activity, selectivity and other biological activities are introduced and summarized. Copyright © 2017 Elsevier Masson SAS. All rights reserved.

A comparative study based on docking and molecular dynamics simulations over HDAC-tubulin dual inhibitors.

PubMed

Hassanzadeh, Malihe; Bagherzadeh, Kowsar; Amanlou, Massoud

2016-11-01

Nowadays the ability to prediction of complex behavior rationally based on the computational approaches has been a successful technique in drug discovery. In the present study interactions of a new series of hybrids, which were made by linking colchicine as a tubulin inhibitor and suberoylanilide hydroxamic acid (SAHA) as a HDAC inhibitor, with HDAC8 and HDAC1 were investigated and compared. This research has been facilitated by the availability of experimental information besides employing docking methodology as well as classical molecular dynamics simulations and binding free energy calculation were performed. The obtained findings indicate different modes of interactions and inhibition strengths of the studied inhibitors for HDAC8 and HDAC1. HDAC8 binding free energies (-34.35 to -26.27kcal/mol) revealed higher binding affinity to HDAC8 compared to HDAC1 (-33.17 to -7.99kcal/mol). The binding energy contribution of each residue with the hybrid compounds 4a-4e within the active site of HDAC1 and HDAC8 was analyzed and the results confirmed the rule of key amino acids in interaction with the hybrid compounds. Copyright © 2016 Elsevier Inc. All rights reserved.

Approaches for Studying the Subcellular Localization, Interactions, and Regulation of Histone Deacetylase 5 (HDAC5)

PubMed Central

Guise, Amanda J.; Cristea, Ileana M.

2017-01-01

As a member of the class IIa family of histone deacetylases, the histone deacetylase 5 (HDAC5) is known to undergo nuclear–cytoplasmic shuttling and to be a critical transcriptional regulator. Its misregulation has been linked to prominent human diseases, including cardiac diseases and tumorigenesis. In this chapter, we describe several experimental methods that have proven effective for studying the functions and regulatory features of HDAC5. We present methods for assessing the subcellular localization, protein interactions, posttranslational modifications (PTMs), and activity of HDAC5 from the standpoint of investigating either the endogenous protein or tagged protein forms in human cells. Specifically, given that at the heart of HDAC5 regulation lie its dynamic localization, interactions, and PTMs, we present methods for assessing HDAC5 localization in fixed and live cells, for isolating HDAC5-containing protein complexes to identify its interactions and modifications, and for determining how these PTMs map to predicted HDAC5 structural motifs. Lastly, we provide examples of approaches for studying HDAC5 functions with a focus on its regulation during cell-cycle progression. These methods can readily be adapted for the study of other HDACs or non-HDAC-proteins of interest. Individually, these techniques capture temporal and spatial snapshots of HDAC5 functions; yet together, these approaches provide powerful tools for investigating both the regulation and regulatory roles of HDAC5 in different cell contexts relevant to health and disease. PMID:27246208

Synthesis, molecular docking and biological evaluation as HDAC inhibitors of cyclopeptide mimetics by a tandem three-component reaction and intramolecular [3+2] cycloaddition.

PubMed

Pirali, Tracey; Faccio, Valeria; Mossetti, Riccardo; Grolla, Ambra A; Di Micco, Simone; Bifulco, Giuseppe; Genazzani, Armando A; Tron, Gian Cesare

2010-02-01

Novel macrocyclic peptide mimetics have been synthesized by exploiting a three-component reaction and an azide-alkyne [3 + 2] cycloaddition. The prepared compounds were screened as HDAC inhibitors allowing us to identify a new compound with promising biological activity. In order to rationalize the biological results, computational studies have also been performed.

Mechanisms of p53-Mediated Apoptosis

DTIC Science & Technology

2007-03-01

Bonnet, P. Dikkes, A. Sharpe, F. McKeon, and D. Caput. 2000. p73-deficient mice have neurological, pheromonal and inflammatory defects but lack...TTT TTG GAA A-3’ and HDAC1-si- CR-R: 5’-AGC TTT TCC AAA AAG CAG ATG CAG AGA TTC AAC TCT CTT GAA GTT GAA TCT CTG CAT CTG CGG G-3’ with HDAC1 targeting

Kinetic Analysis and Quantification of [11C]Martinostat for in vivo HDAC Imaging of the Brain

PubMed Central

Wey, Hsiao-Ying; Wang, Changning; Schroeder, Frederick A.; Logan, Jean; Price, Julie C.; Hooker, Jacob M.

2015-01-01

Epigenetic mechanisms mediated by histone deacetylases (HDACs) have been implicated in a wide-range of CNS disorders and may offer new therapeutic opportunities. In vivo evaluation of HDAC density and drug occupancy has become possible with [11C]Martinostat, which exhibits selectivity for a subset of class I/IIb HDAC enzymes. In this study, we characterize the kinetic properties of [11C]Martinostat in the nonhuman primate (NHP) brain in preparation for human neuroimaging studies. The goal of this work was to determine whether classic compartmental analysis techniques were appropriate and to further determine if arterial plasma is required for future NHP studies. Using an arterial plasma input function, several analysis approaches were evaluated for robust outcome measurements. [11C]Martinostat showed high baseline distribution volume (VT) ranging from 29.9–54.4 mL/cm3 in the brain and large changes in occupancy (up to 99%) with a blocking dose approaches full enzyme saturation. An averaged nondisplaceable tissue uptake (VND) of 8.6 ± 3.7 mL/cm3 suggests high specific binding of [11C]Martinostat. From a two-tissue compartment model, [11C]Martinostat exhibits a high K1 (averaged K1 of 0.65 mL/cm3/min) and a small k4 (average of 0.0085 min−1). Our study supports that [11C]Martinostat can be used to detect changes in HDAC density and occupancy in vivo and that simplified analysis not using arterial blood could be appropriate. PMID:25768025

Kinetic Analysis and Quantification of [ 11C]Martinostat for in Vivo HDAC Imaging of the Brain

DOE PAGES

Wey, Hsiao-Ying; Wang, Changning; Schroeder, Frederick A.; ...

2015-03-13

We report that epigenetic mechanisms mediated by histone deacetylases (HDACs) have been implicated in a wide-range of CNS disorders and may offer new therapeutic opportunities. In vivo evaluation of HDAC density and drug occupancy has become possible with [ 11C]Martinostat, which exhibits selectivity for a subset of class I/IIb HDAC enzymes. In this study, we characterize the kinetic properties of [ 11C]Martinostat in the nonhuman primate (NHP) brain in preparation for human neuroimaging studies. The goal of this work was to determine whether classic compartmental analysis techniques were appropriate and to further determine if arterial plasma is required for futuremore » NHP studies. Using an arterial plasma input function, several analysis approaches were evaluated for robust outcome measurements. [ 11C]Martinostat showed high baseline distribution volume (V T) ranging from 29.9 to 54.4 mL/cm 3 in the brain and large changes in occupancy (up to 99%) with a blocking dose approaching full enzyme saturation. An averaged nondisplaceable tissue uptake (VND) of 8.6 ± 3.7 mL/cm 3 suggests high specific binding of [ 11C]Martinostat. From a two-tissue compartment model, [ 11C]Martinostat exhibits a high K 1 (averaged K 1 of 0.65 mL/cm 3/min) and a small k 4 (average of 0.0085 min –1). In conclusion, our study supports that [ 11C]Martinostat can be used to detect changes in HDAC density and occupancy in vivo and that simplified analysis not using arterial blood could be appropriate.« less

Methamphetamine Causes Differential Alterations in Gene Expression and Patterns of Histone Acetylation/Hypoacetylation in the Rat Nucleus Accumbens

PubMed Central

Martin, Tracey A.; Jayanthi, Subramaniam; McCoy, Michael T.; Brannock, Christie; Ladenheim, Bruce; Garrett, Tiffany; Lehrmann, Elin; Becker, Kevin G.; Cadet, Jean Lud

2012-01-01

Methamphetamine (METH) addiction is associated with several neuropsychiatric symptoms. Little is known about the effects of METH on gene expression and epigenetic modifications in the rat nucleus accumbens (NAC). Our study investigated the effects of a non-toxic METH injection (20 mg/kg) on gene expression, histone acetylation, and the expression of the histone acetyltransferase (HAT), ATF2, and of the histone deacetylases (HDACs), HDAC1 and HDAC2, in that structure. Microarray analyses done at 1, 8, 16 and 24 hrs after the METH injection identified METH-induced changes in the expression of genes previously implicated in the acute and longterm effects of psychostimulants, including immediate early genes and corticotropin-releasing factor (Crf). In contrast, the METH injection caused time-dependent decreases in the expression of other genes including Npas4 and cholecystokinin (Cck). Pathway analyses showed that genes with altered expression participated in behavioral performance, cell-to-cell signaling, and regulation of gene expression. PCR analyses confirmed the changes in the expression of c-fos, fosB, Crf, Cck, and Npas4 transcripts. To determine if the METH injection caused post-translational changes in histone markers, we used western blot analyses and identified METH-mediated decreases in histone H3 acetylated at lysine 9 (H3K9ac) and lysine 18 (H3K18ac) in nuclear sub-fractions. In contrast, the METH injection caused time-dependent increases in acetylated H4K5 and H4K8. The changes in histone acetylation were accompanied by decreased expression of HDAC1 but increased expression of HDAC2 protein levels. The histone acetyltransferase, ATF2, showed significant METH-induced increased in protein expression. These results suggest that METH-induced alterations in global gene expression seen in rat NAC might be related, in part, to METH-induced changes in histone acetylation secondary to changes in HAT and HDAC expression. The causal role that HATs and HDACs might play in METH-induced gene expression needs to be investigated further. PMID:22470541

Studies of benzamide- and thiol-based histone deacetylase inhibitors in models of oxidative-stress-induced neuronal death: identification of some HDAC3-selective inhibitors.

PubMed

Chen, Yufeng; He, Rong; Chen, Yihua; D'Annibale, Melissa A; Langley, Brett; Kozikowski, Alan P

2009-05-01

We compare three structurally different classes of histone deacetylase (HDAC) inhibitors that contain benzamide, hydroxamate, or thiol groups as the zinc binding group (ZBG) for their ability to protect cortical neurons in culture from cell death induced by oxidative stress. This study reveals that none of the benzamide-based HDAC inhibitors (HDACIs) provides any neuroprotection whatsoever, in distinct contrast to HDACIs that contain other ZBGs. Some of the sulfur-containing HDACIs, namely the thiols, thioesters, and disulfides present modest neuroprotective activity but show toxicity at higher concentrations. Taken together, these data demonstrate that the HDAC6-selective mercaptoacetamides that were reported previously provide the best protection in the homocysteic acid model of oxidative stress, thus further supporting their study in animal models of neurodegenerative diseases.

Largazole, a class I histone deacetylase inhibitor, enhances TNF-α-induced ICAM-1 and VCAM-1 expression in rheumatoid arthritis synovial fibroblasts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ahmed, Salahuddin, E-mail: Salah.Ahmed@utoledo.edu; Riegsecker, Sharayah; Beamer, Maria

In the present study, we evaluated the effect of largazole (LAR), a marine-derived class I HDAC inhibitor, on tumor necrosis factor-α (TNF-α)-induced expression of intercellular adhesion molecule-1 (ICAM-1) and vascular cell adhesion molecule-1 (VCAM-1), and matrix metalloproteinase-2 (MMP-2) activity. LAR (1–5 μM) had no adverse effect on the viability of RA synovial fibroblasts. Among the different class I HDACs screened, LAR (0.5–5 μM) inhibited the constitutive expression of HDAC1 (0–30%). Surprisingly, LAR increased class II HDAC [HDAC6] by ∼ 220% with a concomitant decrease in HDAC5 [30–58%] expression in RA synovial fibroblasts. SAHA (5 μM), a pan-HDAC inhibitor, also inducedmore » HDAC6 expression in RA synovial fibroblasts. Pretreatment of RA synovial fibroblasts with LAR further enhanced TNF-α-induced ICAM-1 and VCAM-1 expression. However, LAR inhibited TNF-α-induced MMP-2 activity in RA synovial fibroblasts by 35% when compared to the TNF-α-treated group. Further, the addition of HDAC6 specific inhibitor Tubastatin A with LAR suppressed TNF-α + LAR-induced ICAM-1 and VCAM-1 expression and completely blocked MMP-2 activity, suggesting a role of HDAC6 in LAR-induced ICAM-1 and VCAM-1 expression. LAR also enhanced TNF-α-induced phospho-p38 and phospho-AKT expression, but inhibited the expression of phospho-JNK and nuclear translocation of NF-κBp65 in RA synovial fibroblasts. These results suggest that LAR activates p38 and Akt pathways and influences class II HDACs, in particular HDAC6, to enhance some of the detrimental effects of TNF-α in RA synovial fibroblasts. Understanding the exact role of different HDAC isoenzymes in RA pathogenesis is extremely important in order to develop highly effective HDAC inhibitors for the treatment of RA. - Highlights: • Largazole enhances TNF-α-induced ICAM-1 and VCAM-1. • Largazole upregulates class II HDAC (HDAC6) in RA synovial fibroblasts. • Largazole also induces the expression of phospho-p38 and phospho-Akt. • A selective HDAC isoform inhibitor may be more effective than a class inhibitor. • Further studies are required to understand the role of class II HDACs in RA.« less

Long Noncoding RNA H19 Promotes Neuroinflammation in Ischemic Stroke by Driving Histone Deacetylase 1-Dependent M1 Microglial Polarization.

PubMed

Wang, Jue; Zhao, Haiping; Fan, Zhibin; Li, Guangwen; Ma, Qingfeng; Tao, Zhen; Wang, Rongliang; Feng, Juan; Luo, Yumin

2017-08-01

Long noncoding RNA H19 is repressed after birth, but can be induced by hypoxia. We aim to investigate the impact on and underlying mechanism of H19 induction after ischemic stroke. Circulating H19 levels in stroke patients and mice subjected to middle cerebral artery occlusion were assessed using real-time polymerase chain reaction. H19 siRNA and histone deacetylase 1 (HDAC1) plasmid were used to knock down H19 and overexpress HDAC1, respectively. Microglial polarization and ischemic outcomes were assessed in middle cerebral artery occlusion mice and BV2 microglial cells subjected to oxygen-glucose deprivation. Circulating H19 levels were significantly higher in stroke patients compared with healthy controls, indicating high diagnostic sensitivity and specificity. Moreover, plasma H19 levels showed a positive correlation with National Institute of Health Stroke Scale score and tumor necrosis factor-α levels. After middle cerebral artery occlusion in mice, H19 levels increased in plasma, white blood cells, and brain. Intracerebroventricular injection of H19 siRNA reduced infarct volume and brain edema, decreased tumor necrosis factor-α and interleukin-1β levels in brain tissue and plasma, and increased plasma interleukin-10 concentrations 24 hours poststroke. Additionally, H19 knockdown attenuated brain tissue loss and neurological deficits 14 days poststroke. BV2 cell-based experiments showed that H19 knockdown blocked oxygen-glucose deprivation-driven M1 microglial polarization, decreased production of tumor necrosis factor-α and CD11b, and increased the expression of Arg-1 and CD206. Furthermore, H19 knockdown reversed oxygen-glucose deprivation-induced upregulation of HDAC1 and downregulation of acetyl-histone H3 and acetyl-histone H4. In contrast, HDAC1 overexpression negated the effects of H19 knockdown. Our findings indicate that H19 promotes neuroinflammation by driving HDAC1-dependent M1 microglial polarization, suggesting a novel H19-based diagnosis and therapy for ischemic stroke. © 2017 American Heart Association, Inc.

Histone deacetylases (HDACs) in XPC gene silencing and bladder cancer

PubMed Central

2011-01-01

Bladder cancer is one of the most common malignancies and causes hundreds of thousands of deaths worldwide each year. Bladder cancer is strongly associated with exposure to environmental carcinogens. It is believed that DNA damage generated by environmental carcinogens and their metabolites causes development of bladder cancer. Nucleotide excision repair (NER) is the major DNA repair pathway for repairing bulk DNA damage generated by most environmental carcinogens, and XPC is a DNA damage recognition protein required for initiation of the NER process. Recent studies demonstrate reduced levels of XPC protein in tumors for a majority of bladder cancer patients. In this work we investigated the role of histone deacetylases (HDACs) in XPC gene silencing and bladder cancer development. The results of our HDAC inhibition study revealed that the treatment of HTB4 and HTB9 bladder cancer cells with the HDAC inhibitor valproic acid (VPA) caused an increase in transcription of the XPC gene in these cells. The results of our chromatin immunoprecipitation (ChIP) studies indicated that the VPA treatment caused increased binding of both CREB1 and Sp1 transcription factors at the promoter region of the XPC gene for both HTB4 and HTB9 cells. The results of our immunohistochemistry (IHC) staining studies further revealed a strong correlation between the over-expression of HDAC4 and increased bladder cancer occurrence (p < 0.001) as well as a marginal significance of increasing incidence of HDAC4 positivity seen with an increase in severity of bladder cancer (p = 0.08). In addition, the results of our caspase 3 activation studies demonstrated that prior treatment with VPA increased the anticancer drug cisplatin-induced activation of caspase 3 in both HTB4 and HTB9 cells. All of these results suggest that the HDACs negatively regulate transcription of the XPC gene in bladder cancer cells and contribute to the severity of bladder tumors. PMID:21507255

Role of Dorsal Striatum Histone Deacetylase 5 in Incubation of Methamphetamine Craving.

PubMed

Li, Xuan; Carreria, Maria B; Witonsky, Kailyn R; Zeric, Tamara; Lofaro, Olivia M; Bossert, Jennifer M; Zhang, Jianjun; Surjono, Felicia; Richie, Christopher T; Harvey, Brandon K; Son, Hyeon; Cowan, Christopher W; Nestler, Eric J; Shaham, Yavin

2017-12-29

Methamphetamine (meth) seeking progressively increases after withdrawal (incubation of meth craving). We previously demonstrated an association between histone deacetylase 5 (HDAC5) gene expression in the rat dorsal striatum and incubation of meth craving. Here we used viral constructs to study the causal role of dorsal striatum HDAC5 in this incubation. In experiment 1 (overexpression), we injected an adeno-associated virus bilaterally into dorsal striatum to express either green fluorescent protein (control) or a mutant form of HDAC5, which strongly localized to the nucleus. After training rats to self-administer meth (10 days, 9 hours/day), we tested the rats for relapse to meth seeking on withdrawal days 2 and 30. In experiment 2 (knockdown), we injected an adeno-associated virus bilaterally into the dorsal striatum to express a short hairpin RNA either against luciferase (control) or against HDAC5. After training rats to self-administer meth, we tested the rats for relapse on withdrawal days 2 and 30. We also measured gene expression of other HDACs and potential HDAC5 downstream targets. We found that HDAC5 overexpression in dorsal striatum increased meth seeking on withdrawal day 30 but not day 2. In contrast, HDAC5 knockdown in the dorsal striatum decreased meth seeking on withdrawal day 30 but not on day 2; this manipulation also altered other HDACs (Hdac1 and Hdac4) and potential HDAC5 targets (Gnb4 and Suv39h1). Results demonstrate a novel role of dorsal striatum HDAC5 in incubation of meth craving. These findings also set up future work to identify HDAC5 targets that mediate this incubation. Published by Elsevier Inc.

HDAC5-LSD1 axis regulates antineoplastic effect of natural HDAC inhibitor sulforaphane in human breast cancer cells.

PubMed

Cao, Chunyu; Wu, Hao; Vasilatos, Shauna N; Chandran, Uma; Qin, Ye; Wan, Yong; Oesterreich, Steffi; Davidson, Nancy E; Huang, Yi

2018-04-06

Our recent studies have shown that cross-talk between histone deacetylase 5 (HDAC5) and lysine-specific demethylase 1 (LSD1) facilitates breast cancer progression. In this work, we demonstrated that regulatory activity at -356 to -100 bp promoter element plays a critical role in governing HDAC5 transcription. By using DNA affinity precipitation and mass spectrometry, we identified a group of factors that bind to this element. Among these factors, Upstream Transcription Factor 1 (USF1) was shown to play a critical role in controlling HDAC5 transcription. Through screening a panel of epigenetic modifying drugs, we showed that a natural bioactive HDAC inhibitor, sulforaphane, downregulated HDAC5 transcription by blocking USF1 activity. Sulforaphane facilitated LSD1 ubiquitination and degradation in an HDAC5-dependent manner. A comparative microarray analysis demonstrated a genome wide cooperative effect of HDAC5 and LSD1 on cancer-related gene expression. shRNA knockdown and sulforaphane inhibition of HDAC5/LSD1 exhibited similar effects on expression of HDAC5/LSD1 target genes. We also showed that coordinated cross-talk of HDAC5 and LSD1 is essential for the antitumor efficacy of sulforaphane. Combination treatment with sulforaphane and a potent LSD1 inhibitor resulted in synergistic growth inhibition in breast cancer cells, but not in normal breast epithelial cells. Furthermore, combined therapy with sulforaphane and LSD1 inhibitor exhibited superior inhibitory effect on MDA-MB-231 xenograft tumor growth. Taken together, our work demonstrates that HDAC5-LSD1 axis is an effective drug target for breast cancer. Inhibition of HDAC5-LSD1 axis with sulforaphane blocks breast cancer growth and combined treatment with LSD1 inhibitor improves the therapeutic efficacy of sulforaphane. © 2018 UICC.

Histone Deacetylase 2 Is a Component of Influenza A Virus-Induced Host Antiviral Response.

PubMed

Nagesh, Prashanth T; Hussain, Mazhar; Galvin, Henry D; Husain, Matloob

2017-01-01

Host cells produce variety of antiviral factors that create an antiviral state and target various stages of influenza A virus (IAV) life cycle to inhibit infection. However, IAV has evolved various strategies to antagonize those antiviral factors. Recently, we reported that a member of class I host histone deacetylases (HDACs), HDAC1 possesses an anti-IAV function. Herein, we provide evidence that HDAC2, another class I member and closely related to HDAC1 in structure and function, also possesses anti-IAV properties. In turn, IAV, like HDAC1, dysregulates HDAC2, mainly at the polypeptide level through proteasomal degradation to potentially minimize its antiviral effect. We found that IAV downregulated the HDAC2 polypeptide level in A549 cells in an H1N1 strain-independent manner by up to 47%, which was recovered to almost 100% level in the presence of proteasome-inhibitor MG132. A further knockdown in HDAC2 expression by up to 90% via RNA interference augmented the growth kinetics of IAV in A549 cells by more than four-fold after 24 h of infection. Furthermore, the knockdown of HDAC2 expression decreased the IAV-induced phosphorylation of the transcription factor, Signal Transducer and Activator of Transcription I (STAT1) and the expression of interferon-stimulated gene, viperin in infected cells by 41 and 53%, respectively. The role of HDAC2 in viperin expression was analogous to that of HDAC1, but it was not in the phosphorylation of STAT1. This indicated that, like HDAC1, HDAC2 is a component of IAV-induced host innate antiviral response and performs both redundant and non-redundant functions vis-a-vis HDAC1; however, IAV dysregulates them both in a redundant manner.

HDAC1 and HDAC2 are Differentially Expressed in Endometriosis

PubMed Central

Colón-Díaz, Maricarmen; Báez-Vega, Perla; García, Miosotis; Ruiz, Abigail; Monteiro, Janice B.; Fourquet, Jessica; Bayona, Manuel; Alvarez-Garriga, Carolina; Achille, Alexandra; Seto, Edward; Flores, Idhaliz

2012-01-01

Epigenetic mechanisms have been ascribed important roles in endometriosis. Covalent histone modifications at lysine residues have been shown to regulate gene expression and thus contribute to pathological states in many diseases. In endometriosis, histone deacetylase inhibition (HDACi) resulted in reactivation of E-cadherin, attenuation of invasion, decreased proliferation of endometriotic cells, and caused lesion regression in an animal model. This study was conducted to assess basal and hormone-regulated gene expression levels of HDAC1 and HDAC2 (HDAC1/2) in cell lines and protein expression levels in tissues. Basal and steroid hormone-regulated HDAC1/2 gene expression levels were determined by quantitative polymerase chain reaction in cell lines and tissues. Protein levels were measured by immunohistochemistry (IHC) in tissues on an endometriosis tissue microarray (TMA). Basal HDAC1/2 gene expression levels were significantly higher in endometriotic versus endometrial stromal cells, which was confirmed by Western blot analysis. Estradiol (E2) and progesterone (P4) significantly downregulated HDAC1 expression in endometrial epithelial cells. Levels of HDAC2 were upregulated by E2 and downregulated by E2 + P4 in endometrial stromal cells. Hormone modulation of HDAC1/2 gene expression was lost in the endometriotic cell line. Immunohistochemistry showed that HDAC1/2 proteins were expressed in a substantial proportion of lesions and endometrium from patients, and their expression levels varied according to lesion localization. The highest proportion of strong HDAC1 immunostaining was seen in ovarian, skin, and gastrointestinal lesions, and of HDAC2 in skin lesions and endometrium from patients with endometriosis. These studies suggest that endometriosis etiology may be partially explained by epigenetic regulation of gene expression due to dysregulations in the expression of HDACs. PMID:22344732

A structure-based virtual screening approach toward the discovery of histone deacetylase inhibitors: identification of promising zinc-chelating groups.

PubMed

Park, Hwangseo; Kim, Sukyoung; Kim, Yong Eun; Lim, Soo-Jeong

2010-04-06

The inhibitors of histone deacetylases (HDACs) have drawn a great deal of attention due to their promising potential as small-molecule therapeutics for the treatment of cancer. By means of virtual screening with docking simulations under consideration of the effects of ligand solvation, we were able to identify six novel HDAC inhibitors with IC(50) values ranging from 1 to 100 muM. These newly identified inhibitors are structurally diverse and have various chelating groups for the active site zinc ion, including N-[1,3,4]thiadiazol-2-yl sulfonamide, N-thiazol-2-yl sulfonamide, and hydroxamic acid moieties. The former two groups are included in many drugs in current clinical use and have not yet been reported as HDAC inhibitors. Therefore, they can be considered as new inhibitor scaffolds for the development of anticancer drugs by structure-activity relationship studies to improve the inhibitory activities against HDACs. Interactions with the HDAC1 active site residues responsible for stabilizing these new inhibitors are addressed in detail.

Protein Aggregates Are Recruited to Aggresome by Histone Deacetylase 6 via Unanchored Ubiquitin C Termini

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ouyang, Hui; Ali, Yousuf O.; Ravichandran, Mani

2012-07-11

The aggresome pathway is activated when proteasomal clearance of misfolded proteins is hindered. Misfolded polyubiquitinated protein aggregates are recruited and transported to the aggresome via the microtubule network by a protein complex consisting of histone deacetylase 6 (HDAC6) and the dynein motor complex. The current model suggests that HDAC6 recognizes protein aggregates by binding directly to polyubiquitinated proteins. Here, we show that there are substantial amounts of unanchored ubiquitin in protein aggregates with solvent-accessible C termini. The ubiquitin-binding domain (ZnF-UBP) of HDAC6 binds exclusively to the unanchored C-terminal diglycine motif of ubiquitin instead of conjugated polyubiquitin. The unanchored ubiquitin Cmore » termini in the aggregates are generated in situ by aggregate-associated deubiquitinase ataxin-3. These results provide structural and mechanistic bases for the role of HDAC6 in aggresome formation and further suggest a novel ubiquitin-mediated signaling pathway, where the exposure of ubiquitin C termini within protein aggregates enables HDAC6 recognition and transport to the aggresome.« less

Nuclear Accumulation of Histone Deacetylase 4 (HDAC4) Exerts Neurotoxicity in Models of Parkinson's Disease.

PubMed

Wu, Qimei; Yang, Xiaoyu; Zhang, Lei; Zhang, Yu; Feng, Linyin

2017-11-01

Histone deacetylase 4 (HDAC4) is a class II HDAC which is highly expressed in the brain. Previous reports have shown that HDAC4 is essential for normal brain physiology and its deregulation leads to several neurodegenerative disorders. However, it remains unclear whether dysregulation of HDAC4 is specifically involved in the development of Parkinson's disease. In this study, we demonstrate that intracellular trafficking of HDAC4 is important in regulating dopaminergic cell death. While HDAC4 normally localizes to the cytoplasm, nuclear accumulation of HDAC4 was observed in dopaminergic neurons overexpressing A53T mutant α-synuclein treated with MPP + /MPTP in vitro and in vivo. Nuclear-localized HDAC4 repressed cAMP response element-binding protein (CREB) and myocyte enhancer factor 2A (MEF2A), altered neuronal gene expression, and promoted neuronal apoptosis. Furthermore, cytoplasm-to-nucleus shuttling of HDAC4 was determined by its phosphorylation status, which was regulated by PP2A and PKCε. Treatment with PKCε-specific activators, DCP-LA or Bryostatin 1, provided neuroprotection against MPP + toxicity in a dose-dependent manner. In summary, our research illustrated that intracellular trafficking of HDAC4 contributes to the vulnerability of cells expressing pathogenic α-synuclein mutants in response to oxidative stress and compounds which maintain cytoplasmic localization of HDAC4 such as PKCε activators that may serve as therapeutic agents for Parkinson's disease.

Apigenin Ameliorates Post-Stroke Cognitive Deficits in Rats Through Histone Acetylation-Mediated Neurochemical Alterations.

PubMed

Tu, Fengxia; Pang, Qiongyi; Huang, Tingting; Zhao, Yun; Liu, Meixia; Chen, Xiang

2017-08-19

BACKGROUND To identify the effect of apigenin on cognitive deficits of rats after cerebral ischemia and reperfusion injury, and to investigate the potential molecular mechanisms. MATERIAL AND METHODS The rats were given sodium butyrate (NaB) or apigenin (20 or 40 mg/kg) for 28 days. Cognition was investigated by the Morris water maze (MWM) test. On day 28, the rats were euthanized and their hippocampal brain regions were used to identify biochemical and neurochemical alterations. The content of histone deacetylase (HDAC) was measured by enzyme-linked immunosorbent assay (ELISA). Western blot analysis was performed to determine the levels of BDNF, phosphorylated cAMP response element-binding protein (pCREB), acetylated H3, and acetylated H4. The mRNA expressions of brain-derived neurotrophic factor (BDNF) and synapsin-I (Syn-I) were examined by polymerase chain reaction (PCR). RESULTS The rats with chronic administration of apigenin (20 and 40 mg/kg) showed better performance in the MWM task than the model rats; there was no significant difference between the apigenin-treated and NaB-treated rats. At the higher apigenin dose of 40 mg/kg, the HDAC content was decreased, the BDNF level was markedly increased, and acetylated H3 and acetylated H4 expressions and Syn-I expressions in the hippocampus was upregulated compared with the model group. Apigenin at 20 mg/kg did not show reversal of the neurochemical alterations. CONCLUSIONS The improvement effect of apigenin on cognitive impairments after cerebral ischemia and reperfusion injury may involve multiple mechanisms, such as the inhibition of HDAC, induction of BDNF and Syn-I expression, and regulation of histone acetylation.

The functional interactome landscape of the human histone deacetylase family

PubMed Central

Joshi, Preeti; Greco, Todd M; Guise, Amanda J; Luo, Yang; Yu, Fang; Nesvizhskii, Alexey I; Cristea, Ileana M

2013-01-01

Histone deacetylases (HDACs) are a diverse family of essential transcriptional regulatory enzymes, that function through the spatial and temporal recruitment of protein complexes. As the composition and regulation of HDAC complexes are only partially characterized, we built the first global protein interaction network for all 11 human HDACs in T cells. Integrating fluorescence microscopy, immunoaffinity purifications, quantitative mass spectrometry, and bioinformatics, we identified over 200 unreported interactions for both well-characterized and lesser-studied HDACs, a subset of which were validated by orthogonal approaches. We establish HDAC11 as a member of the survival of motor neuron complex and pinpoint a functional role in mRNA splicing. We designed a complementary label-free and metabolic-labeling mass spectrometry-based proteomics strategy for profiling interaction stability among different HDAC classes, revealing that HDAC1 interactions within chromatin-remodeling complexes are largely stable, while transcription factors preferentially exist in rapid equilibrium. Overall, this study represents a valuable resource for investigating HDAC functions in health and disease, encompassing emerging themes of HDAC regulation in cell cycle and RNA processing and a deeper functional understanding of HDAC complex stability. PMID:23752268

Specific requirement of the chromatin modifier mSin3B in cell cycle exit and cellular differentiation

PubMed Central

David, Gregory; Grandinetti, Kathryn B.; Finnerty, Patricia M.; Simpson, Natalie; Chu, Gerald C.; DePinho, Ronald A.

2008-01-01

The Sin3-histone deacetylase (HDAC) corepressor complex is conserved from yeast to humans. Mammals possess two highly related Sin3 proteins, mSin3A and mSin3B, which serve as scaffolds tethering HDAC enzymatic activity, and numerous sequence-specific transcription factors to enable local chromatin regulation at specific gene targets. Despite broad overlapping expression of mSin3A and mSin3B, mSin3A is cell-essential and vital for early embryonic development. Here, genetic disruption of mSin3B reveals a very different phenotype characterized by the survival of cultured cells and lethality at late stages of embryonic development with defective differentiation of multiple lineages—phenotypes that are strikingly reminiscent of those associated with loss of retinoblastoma family members or E2F transcriptional repressors. Additionally, we observe that, whereas mSin3B−/− cells cycle normally under standard growth conditions, they show an impaired ability to exit the cell cycle with limiting growth factors. Correspondingly, mSin3B interacts physically with the promoters of known E2F target genes, and its deficiency is associated with derepression of these gene targets in vivo. Together, these results reveal a critical role for mSin3B in the control of cell cycle exit and terminal differentiation in mammals and establish contrasting roles for the mSin3 proteins in the growth and development of specific lineages. PMID:18332431

Qualitative and Quantitative Analysis of Histone Deacetylases in Kidney Tissue Sections.

PubMed

Ververis, Katherine; Marzully, Selly; Samuel, Chrishan S; Hewitson, Tim D; Karagiannis, Tom C

2016-01-01

Fluorescent microscope imaging technologies are increasing in their applications and are being used on a wide scale. However methods used to quantify the level of fluorescence intensity are often not utilized-perhaps given the result may be immediately seen, quantification of the data may not seem necessary. However there are a number of reasons given to quantify fluorescent images including the importance of removing potential bias in the data upon observation as well as quantification of large numbers of images gives statistical power to detect subtle changes in experiments. In addition discreet localization of a protein could be detected without selection bias that may not be detectable by eye. Such data will be deemed useful when detecting the levels of HDAC enzymes within cells in order to develop more effective HDAC inhibitor compounds for use against multiple diseased states. Hence, we discuss a methodology devised to analyze fluorescent images using Image J to detect the mean fluorescence intensity of the 11 metal-dependent HDAC enzymes using murine kidney tissue sections as an example.

RNAi screen in Drosophila larvae identifies histone deacetylase 3 as a positive regulator of the hsp70 heat shock gene expression during heat shock.

PubMed

Achary, Bhavana G; Campbell, Katie M; Co, Ivy S; Gilmour, David S

2014-05-01

The transcription regulation of the Drosophila hsp70 gene is a complex process that involves the regulation of multiple steps, including the establishment of paused Pol II and release of Pol II into elongation upon heat shock activation. While the major players involved in the regulation of gene expression have been studied in detail, additional factors involved in this process continue to be discovered. To identify factors involved in hsp70 expression, we developed a screen that capitalizes on a visual assessment of heat shock activation using a hsp70-beta galactosidase reporter and publicly available RNAi fly lines to deplete candidate proteins. We validated the screen by showing that the depletion of HSF, CycT, Cdk9, Nurf 301, or ELL prevented the full induction of hsp70 by heat shock. Our screen also identified the histone deacetylase HDAC3 and its associated protein SMRTER as positive regulators of hsp70 activation. Additionally, we show that HDAC3 and SMRTER contribute to hsp70 gene expression at a step subsequent to HSF-mediated activation and release of the paused Pol II that resides at the promoter prior to heat shock induction. Copyright © 2014 Elsevier B.V. All rights reserved.

Potassium Bisperoxo(1,10-phenanthroline)oxovanadate (bpV(phen)) Induces Apoptosis and Pyroptosis and Disrupts the P62-HDAC6 Protein Interaction to Suppress the Acetylated Microtubule-dependent Degradation of Autophagosomes.

PubMed

Chen, Qi; Yue, Fei; Li, Wenjiao; Zou, Jing; Xu, Tao; Huang, Cheng; Zhang, Ye; Song, Kun; Huang, Guanqun; Xu, Guibin; Huang, Hai; Li, Jun; Liu, Leyuan

2015-10-23

Autophagy is a cellular process that controls and executes the turnover of dysfunctional organelles and misfolded or abnormally aggregated proteins. Phosphatase and tensin homologue deleted on chromosome 10 (PTEN) activates the initiation of autophagy. Autophagosomes migrate along acetylated microtubules to fuse with lysosomes to execute the degradation of the engulfed substrates that usually bind with sequestosome 1 (SQSTM1, p62). Microtubule-associated protein 1 light chain 3 (LC3) traces the autophagy process by converting from the LC3-I to the LC3-II isoform and serves as a major marker of autophagy flux. Potassium bisperoxo(1,10-phenanthroline)oxovanadate (bpV(phen)) is an insulin mimic and a PTEN inhibitor and has the potential to treat different diseases. Here we show that bpV(phen) enhances the ubiquitination of p62, reduces the stability of p62, disrupts the interaction between p62 and histone deacetylase 6 (HDAC6), activates the deacetylase activity of HDAC6 on α-tubulin, and impairs stable acetylated microtubules. Microtubular destabilization leads to the blockade of autophagosome-lysosome fusion and accumulation of autophagosomes. Autophagy defects lead to oxidative stress and lysosomal rupture, which trigger different types of cell death, including apoptosis and pyroptosis. The consistent results from multiple systems, including mouse and different types of mammalian cells, are different from the predicted function of bpV(phen) as a PTEN inhibitor to activate autophagy flux. In addition, levels of p62 are reduced but not elevated when autophagosomal degradation is blocked, revealing a novel function of p62 in autophagy regulation. Therefore, it is necessary to pay attention to the roles of bpV(phen) in autophagy, apoptosis, and pyroptosis when it is developed as a drug. © 2015 by The American Society for Biochemistry and Molecular Biology, Inc.

The Histone Deacetylase HDAC4 Regulates Long-Term Memory in Drosophila

PubMed Central

Fitzsimons, Helen L.; Schwartz, Silvia; Given, Fiona M.; Scott, Maxwell J.

2013-01-01

A growing body of research indicates that pharmacological inhibition of histone deacetylases (HDACs) correlates with enhancement of long-term memory and current research is concentrated on determining the roles that individual HDACs play in cognitive function. Here, we investigate the role of HDAC4 in long-term memory formation in Drosophila. We show that overexpression of HDAC4 in the adult mushroom body, an important structure for memory formation, resulted in a specific impairment in long-term courtship memory, but had no affect on short-term memory. Overexpression of an HDAC4 catalytic mutant also abolished LTM, suggesting a mode of action independent of catalytic activity. We found that overexpression of HDAC4 resulted in a redistribution of the transcription factor MEF2 from a relatively uniform distribution through the nucleus into punctate nuclear bodies, where it colocalized with HDAC4. As MEF2 has also been implicated in regulation of long-term memory, these data suggest that the repressive effects of HDAC4 on long-term memory may be through interaction with MEF2. In the same genetic background, we also found that RNAi-mediated knockdown of HDAC4 impairs long-term memory, therefore we demonstrate that HDAC4 is not only a repressor of long-term memory, but also modulates normal memory formation. PMID:24349558

The HDAC complex and cytoskeleton.

PubMed

Kovacs, Jeffery J; Hubbert, Charlotte; Yao, Tso-Pang

2004-01-01

HDAC6 is a cytoplasmic deacetylase that dynamically associates with the microtubule and actin cytoskeletons. HDAC6 regulates growth factor-induced chemotaxis by its unique deacetylase activity towards microtubules or other substrates. Here we describe a non-catalytic structural domain that is essential for HDAC6 function and places HDAC6 as a critical mediator linking the acetylation and ubiquitination network. This evolutionarily conserved motif, termed the BUZ domain, has features of a zinc finger and binds both mono- and polyubiquitinated proteins. Furthermore, the BUZ domain promotes HDAC6 mono-ubiquitination. These results establish the BUZ domain, in addition to the UIM and CUE domains, as a novel motif that both binds ubiquitin and mediates mono-ubiquitination. Importantly, the BUZ domain is essential for HDAC6 to promote chemotaxis, indicating that communication with the ubiquitin network is critical for proper HDAC6 function. The unique presence of the UIM and CUE domains in proteins involved in endocytic trafficking suggests that HDAC6 might also regulate vesicle transport and protein degradation. Indeed, we have found that HDAC6 is actively transported and concentrated in vesicular compartments. We propose that an integration of reversible acetylation and ubiquitination by HDAC6 may be a novel component in regulating the cytoskeleton, vesicle transport and protein degradation.

Active Site Metal Identity Alters Histone Deacetylase 8 Substrate Selectivity: A Potential Novel Regulatory Mechanism.

PubMed

Castaneda, Carol Ann; Lopez, Jeffrey E; Joseph, Caleb G; Scholle, Michael D; Mrksich, Milan; Fierke, Carol A

2017-10-24

Histone deacetylase 8 (HDAC8) is a well-characterized member of the class I acetyl-lysine deacetylase (HDAC) family. Previous work has shown that the efficiency of HDAC8-catalyzed deacetylation of a methylcoumarin peptide varies depending on the identity of the divalent metal ion in the HDAC8 active site. Here we demonstrate that both HDAC8 activity and substrate selectivity for a diverse range of peptide substrates depend on the identity of the active site metal ion. Varied deacetylase activities of Fe(II)- and Zn(II)-HDAC8 toward an array of peptide substrates were identified using self-assembled monolayers for matrix-assisted laser desorption ionization (SAMDI) mass spectrometry. Subsequently, the metal dependence of deacetylation of peptides of biological interest was measured using an in vitro peptide assay. While Fe(II)-HDAC8 is generally more active than Zn(II)-HDAC8, the Fe(II)/Zn(II) HDAC8 activity ratio varies widely (from 2 to 150) among the peptides tested. These data provide support for the hypothesis that HDAC8 may undergo metal switching in vivo that, in turn, may regulate its activity. However, future studies are needed to explore the identity of the metal ion bound to HDAC8 in cells under varied conditions.

HDAC8 functions in spindle assembly during mouse oocyte meiosis

PubMed Central

Shu, Jing; Chen, Xueqin; Shi, Yingjiao; Wang, Ensheng; Wang, Li; Hu, Qinbo; Dai, Yibo; Xiong, Bo

2017-01-01

HDAC8 is a class I histone deacetylase that functions in a variety of biological processes through its non-histone substrates. However, its roles during oocyte meiosis remain elusive. Here, we document that HDAC8 localizes at spindle poles and positively participates in the regulation of microtubule organization and spindle assembly in mouse oocytes. Depletion of HDAC8 by siRNA-based gene silencing results in various spindle defects and chromosome misalignment during oocyte meiotic maturation, accompanied by impaired kinetochore-microtubule attachments. Consequently, a higher incidence of aneuploidy is generated in HDAC8-depleted MII eggs. In addition, inhibition of HDAC8 activity with its selective inhibitor PCI-34051 phenocopies the spindle/chromosome defects resulting from HDAC8 depletion by siRNA injection. Finally, we find that HDAC8 is required for the correct localization of ϕ-tubulin to spindle poles. Collectively, these data reveal that HDAC8 plays a significant role in regulating spindle assembly and thus ensuring the euploidy in mouse eggs. PMID:28223544

Selective class IIa histone deacetylase inhibition via a nonchelating zinc-binding group.

PubMed

Lobera, Mercedes; Madauss, Kevin P; Pohlhaus, Denise T; Wright, Quentin G; Trocha, Mark; Schmidt, Darby R; Baloglu, Erkan; Trump, Ryan P; Head, Martha S; Hofmann, Glenn A; Murray-Thompson, Monique; Schwartz, Benjamin; Chakravorty, Subhas; Wu, Zining; Mander, Palwinder K; Kruidenier, Laurens; Reid, Robert A; Burkhart, William; Turunen, Brandon J; Rong, James X; Wagner, Craig; Moyer, Mary B; Wells, Carrow; Hong, Xuan; Moore, John T; Williams, Jon D; Soler, Dulce; Ghosh, Shomir; Nolan, Michael A

2013-05-01

In contrast to studies on class I histone deacetylase (HDAC) inhibitors, the elucidation of the molecular mechanisms and therapeutic potential of class IIa HDACs (HDAC4, HDAC5, HDAC7 and HDAC9) is impaired by the lack of potent and selective chemical probes. Here we report the discovery of inhibitors that fill this void with an unprecedented metal-binding group, trifluoromethyloxadiazole (TFMO), which circumvents the selectivity and pharmacologic liabilities of hydroxamates. We confirm direct metal binding of the TFMO through crystallographic approaches and use chemoproteomics to demonstrate the superior selectivity of the TFMO series relative to a hydroxamate-substituted analog. We further apply these tool compounds to reveal gene regulation dependent on the catalytic active site of class IIa HDACs. The discovery of these inhibitors challenges the design process for targeting metalloenzymes through a chelating metal-binding group and suggests therapeutic potential for class IIa HDAC enzyme blockers distinct in mechanism and application compared to current HDAC inhibitors.

Structure-activity relationships of hydroxamate-based histone deacetylase-8 inhibitors: reality behind anticancer drug discovery.

PubMed

Amin, Sk Abdul; Adhikari, Nilanjan; Jha, Tarun

2017-12-01

The pan-histone deacetylase (HDAC) inhibitors comprise a fish-like structural orientation where hydrophobic aryl- and zinc-binding groups act as head and tail, respectively of a fish. The linker moiety correlates the body of the fish linking head and tail groups. Despite these pan-HDAC inhibitors, selective HDAC-8 inhibitors are still in demand as a safe remedy. HDAC-8 is involved in invasion and metastasis in cancer. This review deals with the rationale behind HDAC-8 inhibitory activity and selectivity along with detailed structure-activity relationships of diverse hydroxamate-based HDAC-8 inhibitors. HDAC-8 inhibitory potency may be increased by modifying the fish-like pharmacophoric features of such type of pan-HDAC inhibitors. This review may provide a preliminary basis to design and optimize new lead molecules with higher HDAC-8 inhibitory activity. This work may surely enlighten in providing useful information in the field of target-specific anticancer therapy.

HDAC2 deregulation in tumorigenesis is causally connected to repression of immune modulation and defense escape

PubMed Central

Conte, Mariarosaria; Dell'Aversana, Carmela; Benedetti, Rosaria; Petraglia, Francesca; Carissimo, Annamaria; Petrizzi, Valeria Belsito; D'Arco, Alfonso Maria; Abbondanza, Ciro; Nebbioso, Angela; Altucci, Lucia

2015-01-01

Histone deacetylase 2 (HDAC2) is overexpressed or mutated in several disorders such as hematological cancers, and plays a critical role in transcriptional regulation, cell cycle progression and developmental processes. Here, we performed comparative transcriptome analyses in acute myeloid leukemia to investigate the biological implications of HDAC2 silencing versus its enzymatic inhibition using epigenetic-based drug(s). By gene expression analysis of HDAC2-silenced vs wild-type cells, we found that HDAC2 has a specific role in leukemogenesis. Gene expression profiling of U937 cell line with or without treatment of the well-known HDAC inhibitor vorinostat (SAHA) identifies and characterizes several gene clusters where inhibition of HDAC2 ‘mimics’ its silencing, as well as those where HDAC2 is selectively and exclusively regulated by HDAC2 protein expression levels. These findings may represent an important tool for better understanding the mechanisms underpinning immune regulation, particularly in the study of major histocompatibility complex class II genes. PMID:25473896

HDAC1-3 inhibitor MS-275 enhances IL10 expression in RAW264.7 macrophages and reduces cigarette smoke-induced airway inflammation in mice

PubMed Central

Leus, Niek G. J.; van den Bosch, Thea; van der Wouden, Petra E.; Krist, Kim; Ourailidou, Maria E.; Eleftheriadis, Nikolaos; Kistemaker, Loes E. M.; Bos, Sophie; Gjaltema, Rutger A. F.; Mekonnen, Solomon A.; Bischoff, Rainer; Gosens, Reinoud; Haisma, Hidde J.; Dekker, Frank J.

2017-01-01

Chronic obstructive pulmonary disease (COPD) constitutes a major health burden. Studying underlying molecular mechanisms could lead to new therapeutic targets. Macrophages are orchestrators of COPD, by releasing pro-inflammatory cytokines. This process relies on transcription factors such as NF-κB, among others. NF-κB is regulated by lysine acetylation; a post-translational modification installed by histone acetyltransferases and removed by histone deacetylases (HDACs). We hypothesized that small molecule HDAC inhibitors (HDACi) targeting class I HDACs members that can regulate NF-κB could attenuate inflammatory responses in COPD via modulation of the NF-κB signaling output. MS-275 is an isoform-selective inhibitor of HDAC1-3. In precision-cut lung slices and RAW264.7 macrophages, MS-275 upregulated the expression of both pro- and anti-inflammatory genes, implying mixed effects. Interestingly, anti-inflammatory IL10 expression was upregulated in these model systems. In the macrophages, this was associated with increased NF-κB activity, acetylation, nuclear translocation, and binding to the IL10 promoter. Importantly, in an in vivo model of cigarette smoke-exposed C57Bl/6 mice, MS-275 robustly attenuated inflammatory expression of KC and neutrophil influx in the lungs. This study highlights for the first time the potential of isoform-selective HDACi for the treatment of inflammatory lung diseases like COPD. PMID:28344354

Selective inhibitors of zinc-dependent histone deacetylases. Therapeutic targets relevant to cancer.

PubMed

Kollar, Jakub; Frecer, Vladimir

2015-01-01

Histone deacetylases (HDACs), which act on acetylated histones and/or other non-histone protein substrates, represent validated epigenetic targets for the treatment of cancer and other human diseases. The inhibition of HDAC activity was shown to induce cell cycle arrest, differentiation, apoptosis as well as a decrease in proliferation, angiogenesis, migration, and cell resistance to chemotherapy. Targeting single HDAC isoforms with selective inhibitors will help to reveal the role of individual HDACs in cancer development or uncover further biological consequences of protein acetylation. This review focuses on conventional zinc-containing HDACs. In its first part, the biological role of individual HDACs in various types of cancer is summarized. In the second part, promising HDAC inhibitors showing activity both in enzymatic and cell-based assays are surveyed with an emphasis on the inhibitors selective to the individual HDACs.

HDAC4 preserves skeletal muscle structure following long-term denervation by mediating distinct cellular responses.

PubMed

Pigna, Eva; Renzini, Alessandra; Greco, Emanuela; Simonazzi, Elena; Fulle, Stefania; Mancinelli, Rosa; Moresi, Viviana; Adamo, Sergio

2018-02-24

Denervation triggers numerous molecular responses in skeletal muscle, including the activation of catabolic pathways and oxidative stress, leading to progressive muscle atrophy. Histone deacetylase 4 (HDAC4) mediates skeletal muscle response to denervation, suggesting the use of HDAC inhibitors as a therapeutic approach to neurogenic muscle atrophy. However, the effects of HDAC4 inhibition in skeletal muscle in response to long-term denervation have not been described yet. To further study HDAC4 functions in response to denervation, we analyzed mutant mice in which HDAC4 is specifically deleted in skeletal muscle. After an initial phase of resistance to neurogenic muscle atrophy, skeletal muscle with a deletion of HDAC4 lost structural integrity after 4 weeks of denervation. Deletion of HDAC4 impaired the activation of the ubiquitin-proteasome system, delayed the autophagic response, and dampened the OS response in skeletal muscle. Inhibition of the ubiquitin-proteasome system or the autophagic response, if on the one hand, conferred resistance to neurogenic muscle atrophy; on the other hand, induced loss of muscle integrity and inflammation in mice lacking HDAC4 in skeletal muscle. Moreover, treatment with the antioxidant drug Trolox prevented loss of muscle integrity and inflammation in in mice lacking HDAC4 in skeletal muscle, despite the resistance to neurogenic muscle atrophy. These results reveal new functions of HDAC4 in mediating skeletal muscle response to denervation and lead us to propose the combined use of HDAC inhibitors and antioxidant drugs to treat neurogenic muscle atrophy.

Sodium Valproate, a Histone Deacetylase Inhibitor, Is Associated With Reduced Stroke Risk After Previous Ischemic Stroke or Transient Ischemic Attack.

PubMed

Brookes, Rebecca L; Crichton, Siobhan; Wolfe, Charles D A; Yi, Qilong; Li, Linxin; Hankey, Graeme J; Rothwell, Peter M; Markus, Hugh S

2018-01-01

A variant in the histone deacetylase 9 ( HDAC9 ) gene is associated with large artery stroke. Therefore, inhibiting HDAC9 might offer a novel secondary preventative treatment for ischemic stroke. The antiepileptic drug sodium valproate (SVA) is a nonspecific inhibitor of HDAC9. We tested whether SVA therapy given after ischemic stroke was associated with reduced recurrent stroke rate. Data were pooled from 3 prospective studies recruiting patients with previous stroke or transient ischemic attack and long-term follow-up: the South London Stroke Register, The Vitamins to Prevent Stroke Study, and the Oxford Vascular Study. Patients receiving SVA were compared with patients who received antiepileptic drugs other than SVA using survival analysis and Cox Regression. A total of 11 949 patients with confirmed ischemic event were included. Recurrent stroke rate was lower in patient taking SVA (17 of 168) than other antiepileptic drugs (105 of 530; log-rank survival analysis P =0.002). On Cox regression, controlling for potential cofounders, SVA remained associated with reduced stroke (hazard ratio=0.44; 95% confidence interval: 0.3-0.7; P =0.002). A similar result was obtained when patients taking SVA were compared with all cases not taking SVA (Cox regression, hazard ratio=0.47; 95% confidence interval: 0.29-0.77; P =0.003). These results suggest that exposure to SVA, an inhibitor of HDAC, may be associated with a lower recurrent stroke risk although we cannot exclude residual confounding in this study design. This supports the hypothesis that HDAC9 is important in the ischemic stroke pathogenesis and that its inhibition, by SVA or a more specific HDAC9 inhibitor, is worthy of evaluation as a treatment to prevent recurrent ischemic stroke. © 2017 The Authors.

HDAC1 Governs Iron Homeostasis Independent of Histone Deacetylation in Iron-Overload Murine Models.

PubMed

Yin, Xiangju; Wu, Qian; Monga, Jitender; Xie, Enjun; Wang, Hao; Wang, Shufen; Zhang, Huizhen; Wang, Zhan-You; Zhou, Tianhua; Shi, Yujun; Rogers, Jack; Lin, Hening; Min, Junxia; Wang, Fudi

2018-05-01

Iron-overload disorders are common and could lead to significant morbidity and mortality worldwide. Due to limited treatment options, there is a great need to develop novel strategies to remove the excess body iron. To discover potential epigenetic modulator in hepcidin upregulation and subsequently decreasing iron burden, we performed an epigenetic screen. The in vivo effects of the identified compounds were further tested in iron-overload mouse models, including Hfe -/- , Hjv -/- , and hepatocyte-specific Smad4 knockout (Smad4 fl/fl ;Alb-Cre + ) mice. Entinostat (MS-275), the clinical used histone deacetylase 1 (HDAC1) inhibitor, was identified the most potent hepcidin agonist. Consistently, Hdac1-deficient mice also presented higher hepcidin levels than wild-type controls. Notably, the long-term treatment with entinostat in Hfe -/- mice significantly alleviated iron overload through upregulating hepcidin transcription. In contrast, entinostat showed no effect on hepcidin expression and iron levels in Smad4 fl/fl ;Alb-Cre + mice. Further mechanistic studies revealed that HDAC1 suppressed expression of hepcidin through interacting with SMAD4 rather than deacetylation of SMAD4 or histone-H3 on the hepcidin promoter. The findings uncovered HDAC1 as a novel hepcidin suppressor through complexing with SMAD4 but not deacetylation of either histone 3 or SMAD4. In addition, our study suggested a novel implication of entinostat in treating iron-overload disorders. Based on our results, we conclude that entinostat strongly activated hepcidin in vivo and in vitro. HDAC1 could serve as a novel hepcidin suppressor by binding to SMAD4, effect of which is independent of BMP/SMAD1/5/8 signaling. Antioxid. Redox Signal. 28, 1224-1237.

Loss of epigenetic Kruppel-like factor 4 histone deacetylase (KLF-4-HDAC)-mediated transcriptional suppression is crucial in increasing vascular endothelial growth factor (VEGF) expression in breast cancer.

PubMed

Ray, Alpana; Alalem, Mohamed; Ray, Bimal K

2013-09-20

Vascular endothelial growth factor (VEGF) is recognized as an important angiogenic factor that promotes angiogenesis in a series of pathological conditions, including cancer, inflammation, and ischemic disorders. We have recently shown that the inflammatory transcription factor SAF-1 is, at least in part, responsible for the marked increase of VEGF levels in breast cancer. Here, we show that SAF-1-mediated induction of VEGF is repressed by KLF-4 transcription factor. KLF-4 is abundantly present in normal breast epithelial cells, but its level is considerably reduced in breast cancer cells and clinical cancer tissues. In the human VEGF promoter, SAF-1- and KLF-4-binding elements are overlapping, whereas SAF-1 induces and KLF-4 suppresses VEGF expression. Ectopic overexpression of KLF-4 and RNAi-mediated inhibition of endogenous KLF-4 supported the role of KLF-4 as a transcriptional repressor of VEGF and an inhibitor of angiogenesis in breast cancer cells. We show that KLF-4 recruits histone deacetylases (HDACs) -2 and -3 at the VEGF promoter. Chronological ChIP assays demonstrated the occupancy of KLF-4, HDAC2, and HDAC3 in the VEGF promoter in normal MCF-10A cells but not in MDA-MB-231 cancer cells. Co-transfection of KLF-4 and HDAC expression plasmids in breast cancer cells results in synergistic repression of VEGF expression and inhibition of angiogenic potential of these carcinoma cells. Together these results identify a new mechanism of VEGF up-regulation in cancer that involves concomitant loss of KLF-4-HDAC-mediated transcriptional repression and active recruitment of SAF-1-mediated transcriptional activation.

Green tea polyphenols causes cell cycle arrest and apoptosis in prostate cancer cells by suppressing class I histone deacetylases

PubMed Central

Thakur, Vijay S.; Gupta, Sanjay

2012-01-01

Green tea polyphenols (GTPs) reactivate epigenetically silenced genes in cancer cells and trigger cell cycle arrest and apoptosis; however, the mechanisms whereby these effects occur are not well understood. We investigated the molecular mechanisms underlying the antiproliferative effects of GTP, which may be similar to those of histone deacetylase (HDAC) inhibitors. Exposure of human prostate cancer LNCaP cells (harboring wild-type p53) and PC-3 cells (lacking p53) with 10–80 μg/ml of GTP for 24 h resulted in dose-dependent inhibition of class I HDAC enzyme activity and its protein expression. GTP treatment causes an accumulation of acetylated histone H3 in total cellular chromatin, resulting in increased accessibility to bind with the promoter sequences of p21/waf1 and Bax, consistent with the effects elicited by an HDAC inhibitor, trichostatin A. GTP treatment also resulted in increased expression of p21/waf1 and Bax at the protein and message levels in these cells. Furthermore, treatment of cells with proteasome inhibitor, MG132 together with GTP prevented degradation of class I HDACs, compared with cells treated with GTP alone, indicating increased proteasomal degradation of class I HDACs by GTP. These alterations were consistent with G0–G1 phase cell cycle arrest and induction of apoptosis in both cell lines. Our findings provide new insight into the mechanisms of GTP action in human prostate cancer cells irrespective of their p53 status and suggest a novel approach to prevention and/or therapy of prostate cancer achieved via HDAC inhibition. PMID:22114073

Acetylation of histone deacetylase 1 regulates NuRD corepressor complex activity.

PubMed

Yang, Tao; Jian, Wei; Luo, Yi; Fu, Xueqi; Noguchi, Constance; Bungert, Jörg; Huang, Suming; Qiu, Yi

2012-11-23

HDAC1-containing NuRD complex is required for GATA-1-mediated repression and activation. GATA-1 associated with acetylated HDAC1-containing NuRD complex, which has no deacetylase activity, for gene activation. Acetylated HDAC1 converts NuRD complex from a repressor to an activator during GATA-1-directed erythroid differentiation program. HDAC1 acetylation may function as a master regulator for the activity of HDAC1 containing complexes. Histone deacetylases (HDACs) play important roles in regulating cell proliferation and differentiation. The HDAC1-containing NuRD complex is generally considered as a corepressor complex and is required for GATA-1-mediated repression. However, recent studies also show that the NuRD complex is involved in GATA-1-mediated gene activation. We tested whether the GATA-1-associated NuRD complex loses its deacetylase activity and commits the GATA-1 complex to become an activator during erythropoiesis. We found that GATA-1-associated deacetylase activity gradually decreased upon induction of erythroid differentiation. GATA-1-associated HDAC1 is increasingly acetylated after differentiation. It has been demonstrated earlier that acetylated HDAC1 has no deacetylase activity. Indeed, overexpression of an HDAC1 mutant, which mimics acetylated HDAC1, promotes GATA-1-mediated transcription and erythroid differentiation. Furthermore, during erythroid differentiation, acetylated HDAC1 recruitment is increased at GATA-1-activated genes, whereas it is significantly decreased at GATA-1-repressed genes. Interestingly, deacetylase activity is not required for Mi2 remodeling activity, suggesting that remodeling activity may be required for both activation and repression. Thus, our data suggest that NuRD can function as a coactivator or repressor and that acetylated HDAC1 converts the NuRD complex from a repressor to an activator during GATA-1-directed erythroid differentiation.

Effect of the angiotensin II receptor blocker valsartan on cardiac hypertrophy and myocardial histone deacetylase expression in rats with aortic constriction

PubMed Central

XU, WEI-PING; YAO, TONG-QING; JIANG, YI-BO; ZHANG, MAO-ZHEN; WANG, YUE-PENG; YU, YING; LI, JING-XIANG; LI, YI-GANG

2015-01-01

The aim of the present study was to observe the myocardial expression of members of the histone deacetylase (HDAC) family (HDAC2, HDAC5 and HDAC9) in rats with or without myocardial hypertrophy (MH) in the presence and absence of the angiotensin II receptor blocker valsartan. Adult male Wistar rats were randomly divided into three groups (n=6/group): Sham-operated control rats, treated with distilled water (1 ml/day) through gavage; rats with MH (established through aortic constriction), treated with distilled water (1 ml/day) through gavage; and MH + valsartan rats, treated with 20 mg/kg/day valsartan through gavage. Treatments commenced one day after surgery and continued for eight weeks. Body weight (BW), heart weight (HW) and plasma atrial natriuretic peptide (ANP) and brain natriuretic peptide (BNP) levels were determined, and the myocardial expression of HDAC2, HDAC5 and HDAC9 was analyzed through a reverse transcription semi-quantitative polymerase chain reaction. The BWs of the rats in the three groups were similar at baseline; however, after eight weeks the BW of the rats in the MH + valsartan group was significantly reduced compared with that of the MH rats. Furthermore, the HW/BW ratio and plasma ANP and BNP levels were increased, the myocardial HDAC2 expression was significantly upregulated and the HDAC5 and HDAC9 expression was significantly downregulated in the MH rats compared with those in the control rats; however, these changes were significantly attenuated by valsartan. Modulation of myocardial HDAC5, HDAC9 and HDAC2 expression may therefore be one of the anti-hypertrophic mechanisms of valsartan in this rat MH model. PMID:26136964

HDAC inhibitors induce global changes in histone lysine and arginine methylation and alter expression of lysine demethylases.

PubMed

Lillico, Ryan; Sobral, Marina Gomez; Stesco, Nicholas; Lakowski, Ted M

2016-02-05

Histone deacetylase (HDAC) inhibitors are cancer treatments that inhibit the removal of the epigenetic modification acetyllysine on histones, resulting in altered gene expression. Such changes in expression may influence other histone epigenetic modifications. We describe a validated liquid chromatography-tandem mass spectrometry (LC-MS/MS) method to quantify lysine acetylation and methylation and arginine methylation on histones extracted from cultured cells treated with HDAC inhibitors. The HDAC inhibitors vorinostat, mocetinostat and entinostat induced 400-600% hyperacetylation in HEK 293 and K562 cells. All HDAC inhibitors decreased histone methylarginines in HEK 293 cells but entinostat produced dose dependent reductions in asymmetric dimethylarginine, not observed in K562 cells. Vorinostat produced increases in histone lysine methylation and decreased expression of some lysine demethylases (KDM), measured by quantitative PCR. Entinostat had variable effects on lysine methylation and decreased expression of some KDM while increasing expression of others. Mocetinostat produced dose dependent increases in histone lysine methylation by LC-MS/MS. This was corroborated with a multiplex colorimetric assay showing increases in histone H3 lysine 4, 9, 27, 36 and 79 methylation. Increases in lysine methylation were correlated with dose dependent decreases in the expression of seven KDM. Mocetinostat functions as an HDAC inhibitor and a de facto KDM inhibitor. Copyright © 2015 Elsevier B.V. All rights reserved.

Boric acid inhibits embryonic histone deacetylases: A suggested mechanism to explain boric acid-related teratogenicity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Di Renzo, Francesca; Cappelletti, Graziella; Broccia, Maria L.

2007-04-15

Histone deacetylases (HDAC) control gene expression by changing histonic as well as non histonic protein conformation. HDAC inhibitors (HDACi) are considered to be among the most promising drugs for epigenetic treatment for cancer. Recently a strict relationship between histone hyperacetylation in specific tissues of mouse embryos exposed to two HDACi (valproic acid and trichostatin A) and specific axial skeleton malformations has been demonstrated. The aim of this study is to verify if boric acid (BA), that induces in rodents malformations similar to those valproic acid and trichostatin A-related, acts through similar mechanisms: HDAC inhibition and histone hyperacetylation. Pregnant mice weremore » treated intraperitoneally with a teratogenic dose of BA (1000 mg/kg, day 8 of gestation). Western blot analysis and immunostaining were performed with anti hyperacetylated histone 4 (H4) antibody on embryos explanted 1, 3 or 4 h after treatment and revealed H4 hyperacetylation at the level of somites. HDAC enzyme assay was performed on embryonic nuclear extracts. A significant HDAC inhibition activity (compatible with a mixed type partial inhibition mechanism) was evident with BA. Kinetic analyses indicate that BA modifies substrate affinity by a factor {alpha} = 0.51 and maximum velocity by a factor {beta} = 0.70. This work provides the first evidence for HDAC inhibition by BA and suggests such a molecular mechanism for the induction of BA-related malformations.« less

Disposition, Metabolism and Histone Deacetylase and Acetyltransferase Inhibition Activity of Tetrahydrocurcumin and Other Curcuminoids

PubMed Central

Novaes, Júlia T.; Sayre, Casey L.; Majeed, Muhammed; Ho, Emmanuel A.; Oliveira, Ana Luísa de P.; Martinez, Stephanie E.; Davies, Neal M.; Lakowski, Ted M.

2017-01-01

Tetrahydrocurcumin (THC), curcumin and calebin-A are curcuminoids found in turmeric (Curcuma longa). Curcuminoids have been established to have a variety of pharmacological activities and are used as natural health supplements. The purpose of this study was to identify the metabolism, excretion, antioxidant, anti-inflammatory and anticancer properties of these curcuminoids and to determine disposition of THC in rats after oral administration. We developed a UHPLC–MS/MS assay for THC in rat serum and urine. THC shows multiple redistribution phases with corresponding increases in urinary excretion rate. In-vitro antioxidant activity, histone deacetylase (HDAC) activity, histone acetyltransferase (HAT) activity and anti-inflammatory inhibitory activity were examined using commercial assay kits. Anticancer activity was determined in Sup-T1 lymphoma cells. Our results indicate THC was poorly absorbed after oral administration and primarily excreted via non-renal routes. All curcuminoids exhibited multiple pharmacological effects in vitro, including potent antioxidant activity as well as inhibition of CYP2C9, CYP3A4 and lipoxygenase activity without affecting the release of TNF-α. Unlike curcumin and calebin-A, THC did not inhibit HDAC1 and PCAF and displayed a weaker growth inhibition activity against Sup-T1 cells. We show evidence for the first time that curcumin and calebin-A inhibit HAT and PCAF, possibly through a Michael-addition mechanism. PMID:29023392

Fli1 Represses Transcription of the Human α2(I) Collagen Gene by Recruitment of the HDAC1/p300 Complex

PubMed Central

Asano, Yoshihide; Trojanowska, Maria

2013-01-01

Fli1, a member of the Ets transcription factor family, is a key repressor of the human α2(I) collagen (COL1A2) gene. Although our previous studies have delineated that TGF-β induces displacement of Fli1 from the COL1A2 promoter through sequential post-translational modifications, the detailed mechanism by which Fli1 functions as a potent transcriptional repressor of the COL1A2 gene has not been fully investigated. To address this issue, we carried out a series of experiments especially focusing on protein-protein interaction and epigenetic transcriptional regulation. The combination of tandem affinity purification and mass spectrometry identified HDAC1 as a Fli1 interacting protein. Under quiescent conditions, HDAC1 induced deacetylation of Fli1 resulting in an increase of Fli1 DNA binding ability and p300 enhanced this process by promoting the formation of a Fli1-HDAC1-p300 complex. TGF-β-induced phosphorylation of Fli1 at threonine 312 led to disassembly of this protein complex. In quiescent dermal fibroblasts Fli1, HDAC1, and p300 occupied the −404 to −237 region, including the Fli1 binding site, of the COL1A2 promoter. TGF-β induced Fli1 and HDAC1 dissociation from the COL1A2 promoter, while promoting Ets1 and p300 recruitment. Furthermore, acetylation levels of histone H3 around the Fli1 binding site in the COL1A2 promoter inversely correlated with the DNA occupancy of Fli1 and HDAC1, while positively correlating with that of Ets1 and p300. In the functional studies, HDAC1 overexpression magnified the inhibitory effect of Fli1 on the COL1A2 promoter. Moreover, pharmacological blockade of HDAC1 by entinostat enhanced collagen production in dermal fibroblasts. Collectively, these results indicate that under quiescent conditions Fli1 recruits HDAC1/p300 to the COL1A2 promoter and suppresses the expression of the COL1A2 gene by chromatin remodeling through histone deacetylation. TGF-β-dependent phosphorylation of Fli1 at threonine 312 is a critical step regulating the remodeling of the Fli1 transcription repressor complex, leading to transcriptional activation of the COL1A2 gene. PMID:24058639

The promise and perils of HDAC inhibitors in neurodegeneration

PubMed Central

Didonna, Alessandro; Opal, Puneet

2015-01-01

Histone deacetylases (HDACs) represent emerging therapeutic targets in the context of neurodegeneration. Indeed, pharmacologic inhibition of HDACs activity in the nervous system has shown beneficial effects in several preclinical models of neurological disorders. However, the translation of such therapeutic approach to clinics has been only marginally successful, mainly due to our still limited knowledge about HDACs physiological role particularly in neurons. Here, we review the potential benefits along with the risks of targeting HDACs in light of what we currently know about HDAC activity in the brain. PMID:25642438

Comparative modeling and benchmarking data sets for human histone deacetylases and sirtuin families.

PubMed

Xia, Jie; Tilahun, Ermias Lemma; Kebede, Eyob Hailu; Reid, Terry-Elinor; Zhang, Liangren; Wang, Xiang Simon

2015-02-23

Histone deacetylases (HDACs) are an important class of drug targets for the treatment of cancers, neurodegenerative diseases, and other types of diseases. Virtual screening (VS) has become fairly effective approaches for drug discovery of novel and highly selective histone deacetylase inhibitors (HDACIs). To facilitate the process, we constructed maximal unbiased benchmarking data sets for HDACs (MUBD-HDACs) using our recently published methods that were originally developed for building unbiased benchmarking sets for ligand-based virtual screening (LBVS). The MUBD-HDACs cover all four classes including Class III (Sirtuins family) and 14 HDAC isoforms, composed of 631 inhibitors and 24609 unbiased decoys. Its ligand sets have been validated extensively as chemically diverse, while the decoy sets were shown to be property-matching with ligands and maximal unbiased in terms of "artificial enrichment" and "analogue bias". We also conducted comparative studies with DUD-E and DEKOIS 2.0 sets against HDAC2 and HDAC8 targets and demonstrate that our MUBD-HDACs are unique in that they can be applied unbiasedly to both LBVS and SBVS approaches. In addition, we defined a novel metric, i.e. NLBScore, to detect the "2D bias" and "LBVS favorable" effect within the benchmarking sets. In summary, MUBD-HDACs are the only comprehensive and maximal-unbiased benchmark data sets for HDACs (including Sirtuins) that are available so far. MUBD-HDACs are freely available at http://www.xswlab.org/ .

O-GlcNAcylation of histone deacetylases 1 in hepatocellular carcinoma promotes cancer progression.

PubMed

Zhu, Guizhou; Tao, Tao; Zhang, Dongmei; Liu, Xiaojuan; Qiu, Huiyuan; Han, LiJian; Xu, Zhiwei; Xiao, Ying; Cheng, Chun; Shen, Aiguo

2016-08-01

Hepatocellular carcinoma (HCC) is a malignant tumor originating in the liver. Previous studies have indicated that O-GlcNAc transferase (OGT) and histone deacetylase-1 (HDAC1) play important roles in the pathogenesis of HCC. In the present study, we investigated the physical link between OGT and HDAC1. The O-GlcNAcylation of HDAC1 is overexpressed in HCC. We found that HDAC1 has two major sites of O-GlcNAcylation in its histone deacetylase domain. HDAC1 O-GlcNAcylation increases the activated phosphorylation of HDAC1, which enhances its enzyme activity. HDAC1 O-GlcNAc mutants promote the p21 transcription regulation through affecting the acetylation levels of histones from chromosome, and then influence the proliferation of HCC cells. We also found that mutants of O-GlcNAcylation site of HDAC1 affect invasion and migration of HepG2 cells. E-cadherin level is highly up-regulated in HDAC1 O-GlcNAc mutant-treated liver cancer cells, which inhibit the occurrence and development of HCC. Our findings suggest that OGT promotes the O-GlcNAc modification of HDAC1in the development of HCC. Therefore, inhibiting O-GlcNAcylation of HDAC1 may repress the progression of HCC. © The Author 2016. Published by Oxford University Press. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

YY1 Protects Cardiac Myocytes from Pathologic Hypertrophy by Interacting with HDAC5

PubMed Central

Dockstader, Karen; McKinsey, Timothy A.

2008-01-01

YY1 is a transcription factor that can repress or activate the transcription of a variety of genes. Here, we show that the function of YY1 as a repressor in cardiac myocytes is tightly dependent on its ability to interact with histone deacetylase 5 (HDAC5). YY1 interacts with HDAC5, and overexpression of YY1 prevents HDAC5 nuclear export in response to hypertrophic stimuli and the increase in cell size and re-expression of fetal genes that accompany pathological cardiac hypertrophy. Knockdown of YY1 results in up-regulation of all genes present during fetal development and increases the cell size of neonatal cardiac myocytes. Moreover, overexpression of a YY1 deletion construct that does not interact with HDAC5 results in transcription activation, suggesting that HDAC5 is necessary for YY1 function as a transcription repressor. In support of this relationship, we show that knockdown of HDAC5 results in transcription activation by YY1. Finally, we show that YY1 interaction with HDAC5 is dependent on the HDAC5 phosphorylation domain and that overexpression of YY1 reduces HDAC5 phosphorylation in response to hypertrophic stimuli. Our results strongly suggest that YY1 functions as an antihypertrophic factor by preventing HDAC5 nuclear export and that up-regulation of YY1 in human heart failure may be a protective mechanism against pathological hypertrophy. PMID:18632988

Selective inhibition of class I but not class IIb histone deacetylases exerts cardiac protection from ischemia reperfusion

PubMed Central

Aune, Sverre E.; Herr, Daniel J.; Mani, Santhosh K.; Menick, Donald R.

2014-01-01

While inhibition of class I/IIb histone deacetylases (HDACs) protects the mammalian heart from ischemia reperfusion (IR) injury, class selective effects remain unexamined. We hypothesized that selective inhibition of class I HDACs would preserve left ventricular contractile function following IR in isolated hearts. Male Sprague Dawley rats (n=6 per group) were injected with vehicle (dimethylsulfoxide, 0.63 mg/kg), the class I/IIb HDAC inhibitor trichostatin A (1 mg/kg), the class I HDAC inhibitor entinostat (MS-275, 10 mg/kg), or the HDAC6 (class IIb) inhibitor tubastatin A (10 mg/kg). After 24 h, hearts were isolated and perfused in Langendorff mode for 30 min (Sham) or subjected to 30 min global ischemia and 120 min global reperfusion (IR). A saline filled balloon attached to a pressure transducer was placed in the LV to monitor contractile function. After perfusion, LV tissue was collected for measurements of antioxidant protein levels and infarct area. At the conclusion of IR, MS-275 pretreatment was associated with significant preservation of developed pressure, rate of pressure generation, rate of pressure relaxation and rate pressure product, as compared to vehicle treated hearts. There was significant reduction of infarct area with MS-275 pretreatment. Contractile function was not significantly restored in hearts treated with trichostatin A or tubastatin A. Mitochondrial superoxide dismutase (SOD2) and catalase protein and mRNA in hearts from animals pretreated with MS-275 were increased following IR, as compared to Sham. This was associated with a dramatic enrichment of nuclear FOXO3a transcription factor, which mediates the expression of SOD2 and catalase. Tubastatin A treatment was associated with significantly decreased catalase levels after IR. Class I HDAC inhibition elicits protection of contractile function following IR, which is associated with increased expression of endogenous antioxidant enzymes. Class I/IIb HDAC inhibition with trichostatin A or selective inhibition of HDAC6 with tubastatin A was not protective. This study highlights the need for the development of new strategies that target specific HDAC isoforms in cardiac ischemia reperfusion. PMID:24632412

Sodium Butyrate Improves Locomotor Impairment and Early Mortality in a Rotenone-Induced Drosophila Model of Parkinson’s Disease

PubMed Central

St. Laurent, Robyn; O’Brien, Liam M.; Ahmad, S. Tariq

2013-01-01

Parkinson’s disease (PD) is a neurodegenerative disorder primarily affecting the dopaminergic neurons in the nigrastriatal pathway resulting in debilitating motor impairment in both familial and sporadic cases. Histone deacetylase (HDAC) inhibitors have been recently implicated as a therapeutic candidate because of their ability to correct the disrupted HDAC activity in PD and other neurodegenerative diseases. Sodium butyrate (SB), an HDAC inhibitor, reduces degeneration of dopaminergic neurons in a mutant alpha-synuclein Drosophila transgenic model of familial PD. Chronic exposure to the pesticide rotenone also causes selective degeneration of dopaminergic neurons and causes locomotor impairment and early mortality in a Drosophila model of chemically-induced PD. This study investigated the effects of sodium butyrate on locomotor impairment and early mortality in a rotenone-induced PD model. We show that treatment with 10 mM SB-supplemented food rescued the rotenone-induced locomotor impairment and early mortality in flies. Additionally, flies with the genetic knockdown of HDAC activity through Sin3A loss-of-function mutation (Sin3Alof) were resistant to rotenone-induced locomotor impairment and early mortality. Furthermore, SB-supplemented Sin3Alof flies had a modest additive effect for improving locomotor impairment. We also show SB-mediated improvement of rotenone-induced locomotor impairment was associated with elevated dopamine levels in the brain. However, the possibility of SB-mediated protective role through mechanisms independent from dopamine system is also discussed. These findings demonstrate that HDAC inhibitors like SB can ameliorate locomotor impairment in a rotenone-induced PD model. PMID:23623990

Stroke Induces Nuclear Shuttling of Histone Deacetylase 4.

PubMed

Kassis, Haifa; Shehadah, Amjad; Chopp, Michael; Roberts, Cynthia; Zhang, Zheng Gang

2015-07-01

Histone deacetylases (HDACs) 4 and 5 are abundantly expressed in the brain and have been implicated in the regulation of neurodegeneration. Under physiological conditions, HDACs 4 and 5 are expressed in the cytoplasm of brain cells where they cannot directly access chromatin. In response to external stimuli, they can shuttle to the nucleus and regulate gene expression. However, the effect of stroke on nuclear shuttling of HDACs 4 and 5 remains unknown. Using a rat model of middle cerebral artery occlusion, we examined the subcellular localization of HDACs 4 and 5 in the peri-infarct cortex during brain repair after stroke. Stroke significantly increased nuclear HDAC4 immunoreactivity in neurons, but not in astrocytes or in oligodendrocytes, of the peri-infarct cortex at 2, 7, and 14 days after middle cerebral artery occlusion. Neurons with nuclear HDAC4 immunoreactivity distributed across all layers of the peri-infarct cortex and were Ctip2+ excitatory and parvalbumin+ inhibitory neurons. These neurons were not TUNEL or BrdU positive. Furthermore, nuclear HDAC4 immunoreactivity was positively and significantly correlated with increased dendritic, axonal, and myelin densities as determined by microtubule-associated protein 2, phosphorylated neurofilament heavy chain, and myelin basic protein, respectively. Unlike HDAC4, stroke did not alter nuclear localization of HDAC5. Our data show that stroke induces nuclear shuttling of HDAC4 in neurons in the peri-infarct cortex, and that increased nuclear HDAC4 is strongly associated with neuronal remodeling but not with neuronal cell death, suggesting a role for nuclear HDAC4 in promoting neuronal recovery after ischemic injury. © 2015 American Heart Association, Inc.

Entropy as a Driver of Selectivity for Inhibitor Binding to Histone Deacetylase 6.

PubMed

Porter, Nicholas J; Wagner, Florence F; Christianson, David W

2018-05-18

Among the metal-dependent histone deacetylases, the class IIb isozyme HDAC6 is remarkable because of its role in the regulation of microtubule dynamics in the cytosol. Selective inhibition of HDAC6 results in microtubule hyperacetylation, leading to cell cycle arrest and apoptosis, which is a validated strategy for cancer chemotherapy and the treatment of other disorders. HDAC6 inhibitors generally consist of a Zn 2+ -binding group such as a hydroxamate, a linker, and a capping group; the capping group is a critical determinant of isozyme selectivity. Surprisingly, however, even "capless" inhibitors exhibit appreciable HDAC6 selectivity. To probe the chemical basis for this selectivity, we now report high-resolution crystal structures of HDAC6 complexed with capless cycloalkyl hydroxamate inhibitors 1-4. Each inhibitor hydroxamate group coordinates to the catalytic Zn 2+ ion with canonical bidentate geometry. Additionally, the olefin moieties of compounds 2 and 4 bind in an aromatic crevice between the side chains of F583 and F643. Reasoning that similar binding could be achieved in the representative class I isozyme HDAC8, we employed isothermal titration calorimetry to study the thermodynamics of inhibitor binding. These measurements indicate that the entropy of inhibitor binding is generally positive for binding to HDAC6 and negative for binding to HDAC8, resulting in ≤313-fold selectivity for binding to HDAC6 relative to HDAC8. Thus, favorable binding entropy contributes to HDAC6 selectivity. Notably, cyclohexenyl hydroxamate 2 represents a promising lead for derivatization with capping groups that may further enhance its impressive 313-fold thermodynamic selectivity for HDAC6 inhibition.

Prognostic and clinical significance of histone deacetylase 1 expression in breast cancer: A meta-analysis.

PubMed

Qiao, Weiqiang; Liu, Heyang; Liu, Ruidong; Liu, Qipeng; Zhang, Ting; Guo, Wanying; Li, Peng; Deng, Miao

2018-05-05

There are conflicting reports about the role of histone deacetylase 1 (HDAC1) in breast cancer prognosis. Here, we conducted a meta-analysis to investigate the prognostic significance of HDAC1 in breast cancer. We searched different databases to identify studies evaluating the association between HDAC1 expression and its prognostic value in breast cancer. The pooled hazard ratios (HRs) and odds radios (ORs) with 95% confidence intervals (95% CIs) were calculated from these studies to assess specific correlation. Our meta-analysis of four databases identified 7 eligible studies with 1429 total patients. We found that HDAC1 over-expression did not correlate with disease-free survival (DFS) and overall survival (OS) in breast cancer. Subgroup analysis indicated an association between up-regulated HDAC1 expression and better OS (HR = 0.47, 95% CI: 0.23-0.97; P = 0.04) in Asian breast cancer patients. However, false-positive report probability (FPRP) analysis and trial sequential analysis (TSA) indicated that the results need further validation. Furthermore, HDAC1 over-expression was associated with positive estrogen receptor (ER) expression (OR, 3.30; 95% CI, 1.11-9.83; P = 0.03) and negative human epidermal growth factor receptor 2 (HER2) expression (OR, 1.79; 95% CI, 1.22-2.61; P = 0.003), but there were no significant differences between patients based on age, tumor size, lymph node metastasis, nuclear grade, or progesterone receptor (PR) expression. Overall, our meta-analysis demonstrated an association between increased HDAC1 expression and better OS in Asian breast cancer patients. In addition, HDAC1 over-expression correlated with positive ER and negative HER2 expression in breast cancer. However, researches in large patients' randomised controlled trials (RCTs) are needed to confirm the results. Copyright © 2018 Elsevier B.V. All rights reserved.

Epigenetic influences on sensory regeneration: histone deacetylases regulate supporting cell proliferation in the avian utricle.

PubMed

Slattery, Eric L; Speck, Judith D; Warchol, Mark E

2009-09-01

The sensory hair cells of the cochlea and vestibular organs are essential for normal hearing and balance function. The mammalian ear possesses a very limited ability to regenerate hair cells and their loss can lead to permanent sensory impairment. In contrast, hair cells in the avian ear are quickly regenerated after acoustic trauma or ototoxic injury. The very different regenerative abilities of the avian vs. mammalian ear can be attributed to differences in injury-evoked expression of genes that either promote or inhibit the production of new hair cells. Gene expression is regulated both by the binding of cis-regulatory molecules to promoter regions as well as through structural modifications of chromatin (e.g., methylation and acetylation). This study examined effects of histone deacetylases (HDACs), whose main function is to modify histone acetylation, on the regulation of regenerative proliferation in the chick utricle. Cultures of regenerating utricles and dissociated cells from the utricular sensory epithelia were treated with the HDAC inhibitors valproic acid, trichostatin A, sodium butyrate, and MS-275. All of these molecules prevent the enzymatic removal of acetyl groups from histones, thus maintaining nuclear chromatin in a "relaxed" (open) configuration. Treatment with all inhibitors resulted in comparable decreases in supporting cell proliferation. We also observed that treatment with the HDAC1-, 2-, and 3-specific inhibitor MS-275 was sufficient to reduce proliferation and that two class I HDACs--HDAC1 and HDAC2--were expressed in the sensory epithelium of the utricle. These results suggest that inhibition of specific type I HDACs is sufficient to prevent cell cycle entry in supporting cells. Notably, treatment with HDAC inhibitors did not affect the differentiation of replacement hair cells. We conclude that histone deacetylation is a positive regulator of regenerative proliferation but is not critical for avian hair cell differentiation.

Expression of HDAC2 but Not HDAC1 Transcript Is Reduced in Dorsolateral Prefrontal Cortex of Patients with Schizophrenia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schroeder, Frederick A.; Gilbert, Tonya M.; Feng, Ningping

Postmortem brain studies support dysregulated expression of the histone deacetylase enzymes, HDAC1 and HDAC2, as a central feature in diseases including schizophrenia, bipolar disorder, and depression.

Expression of HDAC2 but Not HDAC1 Transcript Is Reduced in Dorsolateral Prefrontal Cortex of Patients with Schizophrenia

DOE PAGES

Schroeder, Frederick A.; Gilbert, Tonya M.; Feng, Ningping; ...

2016-11-28

Postmortem brain studies support dysregulated expression of the histone deacetylase enzymes, HDAC1 and HDAC2, as a central feature in diseases including schizophrenia, bipolar disorder, and depression.

Class IIa Histone Deacetylases Are Conserved Regulators of Circadian Function*

PubMed Central

Fogg, Paul C. M.; O'Neill, John S.; Dobrzycki, Tomasz; Calvert, Shaun; Lord, Emma C.; McIntosh, Rebecca L. L.; Elliott, Christopher J. H.; Sweeney, Sean T.; Hastings, Michael H.; Chawla, Sangeeta

2014-01-01

Class IIa histone deacetylases (HDACs) regulate the activity of many transcription factors to influence liver gluconeogenesis and the development of specialized cells, including muscle, neurons, and lymphocytes. Here, we describe a conserved role for class IIa HDACs in sustaining robust circadian behavioral rhythms in Drosophila and cellular rhythms in mammalian cells. In mouse fibroblasts, overexpression of HDAC5 severely disrupts transcriptional rhythms of core clock genes. HDAC5 overexpression decreases BMAL1 acetylation on Lys-537 and pharmacological inhibition of class IIa HDACs increases BMAL1 acetylation. Furthermore, we observe cyclical nucleocytoplasmic shuttling of HDAC5 in mouse fibroblasts that is characteristically circadian. Mutation of the Drosophila homolog HDAC4 impairs locomotor activity rhythms of flies and decreases period mRNA levels. RNAi-mediated knockdown of HDAC4 in Drosophila clock cells also dampens circadian function. Given that the localization of class IIa HDACs is signal-regulated and influenced by Ca2+ and cAMP signals, our findings offer a mechanism by which extracellular stimuli that generate these signals can feed into the molecular clock machinery. PMID:25271152

Class IIa histone deacetylases are conserved regulators of circadian function.

PubMed

Fogg, Paul C M; O'Neill, John S; Dobrzycki, Tomasz; Calvert, Shaun; Lord, Emma C; McIntosh, Rebecca L L; Elliott, Christopher J H; Sweeney, Sean T; Hastings, Michael H; Chawla, Sangeeta

2014-12-05

Class IIa histone deacetylases (HDACs) regulate the activity of many transcription factors to influence liver gluconeogenesis and the development of specialized cells, including muscle, neurons, and lymphocytes. Here, we describe a conserved role for class IIa HDACs in sustaining robust circadian behavioral rhythms in Drosophila and cellular rhythms in mammalian cells. In mouse fibroblasts, overexpression of HDAC5 severely disrupts transcriptional rhythms of core clock genes. HDAC5 overexpression decreases BMAL1 acetylation on Lys-537 and pharmacological inhibition of class IIa HDACs increases BMAL1 acetylation. Furthermore, we observe cyclical nucleocytoplasmic shuttling of HDAC5 in mouse fibroblasts that is characteristically circadian. Mutation of the Drosophila homolog HDAC4 impairs locomotor activity rhythms of flies and decreases period mRNA levels. RNAi-mediated knockdown of HDAC4 in Drosophila clock cells also dampens circadian function. Given that the localization of class IIa HDACs is signal-regulated and influenced by Ca(2+) and cAMP signals, our findings offer a mechanism by which extracellular stimuli that generate these signals can feed into the molecular clock machinery. © 2014 by The American Society for Biochemistry and Molecular Biology, Inc.

The clinical development of histone deacetylase inhibitors as targeted anticancer drugs.

PubMed

Marks, Paul A

2010-09-01

Histone deacetylase (HDAC) inhibitors are being developed as a new, targeted class of anticancer drugs. This review focuses on the mechanisms of action of the HDAC inhibitors, which selectively induce cancer cell death. There are 11 zinc-dependent HDACs in humans and the biological roles of these lysine deacetylases are not completely understood. It is clear that these different HDACs are not redundant in their activity. This review focuses on the mechanisms by which HDAC inhibitors can induce transformed cell growth arrest and cell death, inhibit cell mobility and have antiangiogenesis activity. There are more than a dozen HDAC inhibitors, including hydroxamates, cyclic peptides, benzamides and fatty acids, in various stages of clinical trials and many more compounds in preclinical development. The chemically different HDAC inhibitors may target different HDACs. There are extensive preclinical studies with transformed cells in culture and tumor-bearing animal models, as well as limited clinical studies reported to date, which indicate that HDAC inhibitors will be most useful when used in combination with cytotoxic or other targeted anticancer agents.

Orally available stilbene derivatives as potent HDAC inhibitors with antiproliferative activities and antitumor effects in human tumor xenografts.

PubMed

Kachhadia, Virendra; Rajagopal, Sridharan; Ponpandian, Thanasekaran; Vignesh, Radhakrishnan; Anandhan, Karnambaram; Prabhu, Daivasigamani; Rajendran, Praveen; Nidhyanandan, Saranya; Roy, Anshu Mittal; Ahamed, Fakrudeen Ali; Surendran, Narayanan; Rajagopal, Sriram; Narayanan, Shridhar; Gopalan, Balasubramanian

2016-01-27

Herein we report the synthesis and activity of a novel class of HDAC inhibitors based on 2, 3-diphenyl acrylic acid derivatives. The compounds in this series have shown to be potent HDAC inhibitors possessing significant antiproliferative activity. Further compounds in this series were subjected to metabolic stability in human liver microsomes (HLM), mouse liver microsomes (MLM), and exhibits promising stability in both. These efforts culminated with the identification of a developmental candidate (5a), which displayed desirable PK/PD relationships, significant efficacy in the xenograft models and attractive ADME profiles. Copyright © 2015 Elsevier Masson SAS. All rights reserved.

Targeting histone deacetylases: perspectives for epigenetic-based therapy in cardio-cerebrovascular disease

PubMed Central

Wang, Zi-Ying; Qin, Wen; Yi, Fan

2015-01-01

Although the pathogenesis of cardio-cerebrovascular disease (CCVD) is multifactorial, an increasing number of experimental and clinical studies have highlighted the importance of histone deacetylase (HDAC)-mediated epigenetic processes in the development of cardio-cerebrovascular injury. HDACs are a family of enzymes to balance the acetylation activities of histone acetyltransferases on chromatin remodeling and play essential roles in regulating gene transcription. To date, 18 mammalian HDACs are identified and grouped into four classes based on similarity to yeast orthologs. The zinc-dependent HDAC family currently consists of 11 members divided into three classes (class I, II, and IV) on the basis of structure, sequence homology, and domain organization. In comparison, class III HDACs (also known as the sirtuins) are composed of a family of NAD+-dependent protein-modifying enzymes related to the Sir2 gene. HDAC inhibitors are a group of compounds that block HDAC activities typically by binding to the zinc-containing catalytic domain of HDACs and have displayed anti-inflammatory and antifibrotic effects in the cardio-cerebrovascular system. In this review, we summarize the current knowledge about classifications, functions of HDACs and their roles and regulatory mechanisms in the cardio-cerebrovascular system. Pharmacological targeting of HDAC-mediated epigenetic processes may open new therapeutic avenues for the treatment of CCVD. PMID:25870619

Acetanilide and bromoacetyl-lysine derivatives as activators for human histone deacetylase 8.

PubMed

Mukhtar, Yusif M; Huang, Yajun; Liu, Jiajia; Chen, Di; Zheng, Weiping

2017-06-01

In the current study, seven compounds (i.e. 1-7) were found to be novel activators for the N ε -acetyl-lysine deacetylation reaction catalyzed by human histone deacetylase 8 (HDAC8). When assessed with the commercially available HDAC8 peptide substrate Fluor-de-Lys®-HDAC8 that harbors the unnatural 7-amino-4-methylcoumarin (AMC) residue immediately C-terminal to the N ε -acetyl-lysine residue to be deacetylated, our compounds exhibited comparable activation potency to that of TM-2-51, the strongest HDAC8 activator reported in the current literature. However, when assessed with an AMC-less peptide substrate derived from the native HDAC8 non-histone substrate protein Zinc finger protein ZNF318, while our compounds were all found to be able to activate HDAC8 deacetylation reaction, TM-2-51 was found not to be able to. Our compounds also seemed to be largely selective for HDAC8 over other classical HDACs. Moreover, treatment with the strongest activator among our compounds (i.e. 7) was found to decrease the K M of the above AMC-less HDAC8 substrate, while nearly maintaining the k cat of the HDAC8-catalyzed deacetylation on this substrate. Copyright © 2017 Elsevier Ltd. All rights reserved.

Anti-inflammatory effects of [6]-shogaol: potential roles of HDAC inhibition and HSP70 induction.

PubMed

Shim, Sehwan; Kim, Sokho; Choi, Dea-Seung; Kwon, Young-Bae; Kwon, Jungkee

2011-11-01

Ginger extracts have been reported to have anti-inflammatory, anti-oxidant, and anti-cancer effects. [6]-shogaol is one of the most bioactive components of ginger rhizomes. This study assessed the [6]-shogaol's ability to protect cultured primary rat astrocytes against lipopolysaccharide (LPS)-induced inflammation. [6]-shogaol was shown to suppress the release of pro-inflammatory cytokines and decreased the level of inducible nitric oxide syntheses (iNOS), cyclooxygenase-2 (COX-2), and phospho-NF-kB in LPS-treated astrocytes. Furthermore, [6]-shogaol treatment markedly up-regulated histone H3 acetylation and suppressed histone deacetylase (HDAC)1 expression. In addition, [6]-shogaol treatment also increased the expression of heat-shock protein (HSP)70. The neuroprotective, neurotrphic, and anti-inflammatory properties of [6]-shogaol may be translated to improvements in neurological performance. [6]-Shogaol's ability to inhibit HDAC was comparable to that of commonly used HDAC inhibitors Trichostatin A and MS275. Taken together, our results suggest that [6]-shogaol can significantly attenuate a variety of neuroinflammatory responses by inducing HSP70, that is associated with HDAC inhibition in cortical astrocytes. Copyright © 2011 Elsevier Ltd. All rights reserved.

gp-91 mediates histone deacetylase inhibition-induced cardioprotection

PubMed Central

Zhao, Ting C; Zhang, Ling X; Cheng, Guangmao; Liu, Jun T

2010-01-01

We have recently shown that the inhibition of histone deacetylases (HDAC) protects the heart against ischemia and reperfusion (I/R) injury. The mechanism by which HDAC inhibition induces cardioprotection remains unknown. We sought to investigate whether the genetic disruption of gp-91, a subunit of NADPH-oxidase, would mitigate cardioprotection of HDAC inhibition. Wild-type and gp-91−/− mice were treated with a potent inhibitor of HDACs, trichostatin A (TSA, 0.1mg/kg, i.p.). Twenty-four hours later, the perfused hearts were subjected to 30 min of ischemia and 30 min of reperfusion. HDAC inhibition in wild-type mice produced marked improvements in ventricular functional recovery and the reduction of infarct size. TSA-induced cardioprotection was eliminated with genetic deletion of gp91. Notably, Western blot and immunostaining displayed a significant increase in gp-91 in myocardium following HDAC inhibition, which resulted in a mildly subsequent increase in the production of reactive oxygen species (ROS). The pretreatment of H9c2 cardiomyoblasts with TSA (50 nmol/L) decreased cell necrosis and increased viability in response to simulated ischemia (SI), which was abrogated by the transfection of cells with gp-91 siRNA, but not by scrambled siRNA. Furthermore, treatment of PLB-985 gp91+/+cells with TSA increased the resistance to SI, which also diminished with genetic disruption of gp91 in gp91phox-deficient PLB-985 cells. TSA treatment inhibited the increased active caspase-3 in H9c2 cardiomyoblasts and PLB-985 gp91+/+cells exposed to SI, which were prevented by knockdown of gp-91 by siRNA. These results suggest that a cascade consisting of gp-91 and HDAC inhibition plays an essential role in orchestrating the cardioprotective effect. PMID:20433879

Characterization of the Regulation and Function of Zinc-Dependent Histone Deacetylases During Mouse Liver Regeneration

PubMed Central

Huang, Jiansheng; Barr, Emily; Rudnick, David A.

2013-01-01

The studies reported here were undertaken to define the regulation and functional importance of zinc-dependent histone deacetylase (Zn-HDAC) activity during liver regeneration using the mouse partial hepatectomy (PH) model. The results showed that hepatic HDAC activity was significantly increased in nuclear and cytoplasmic fractions following PH. Further analyses showed isoform-specific effects of PH on HDAC mRNA and protein expression, with increased expression of the class I HDACs, 1 and 8, and class II HDAC4 in regenerating liver. Hepatic expression of (class II) HDAC5 was unchanged after PH; however HDAC5 exhibited transient nuclear accumulation in regenerating liver. These changes in hepatic HDAC expression, subcellular localization, and activity coincided with diminished histone acetylation in regenerating liver. The significance of these events was investigated by determining the effects of suberoylanilide hydroxyamic acid (SAHA, a specific inhibitor of Zn-HDAC activity) on hepatic regeneration. The results showed that SAHA-treatment suppressed the effects of PH on histone deacetylation and hepatocellular BrdU incorporation. Further examination showed that SAHA blunted hepatic expression and activation of cell cycle signals downstream of induction of cyclin D1 expression in mice subjected to PH. Conclusion The data reported here demonstrate isoform-specific regulation of Zn-HDAC expression, subcellular localization, and activity in regenerating liver. These studies also indicate that HDAC activity promotes liver regeneration by regulating hepatocellular cell cycle progression at a step downstream of cyclin D1 induction. PMID:23258575

Comparative Modeling and Benchmarking Data Sets for Human Histone Deacetylases and Sirtuin Families

PubMed Central

Xia, Jie; Tilahun, Ermias Lemma; Kebede, Eyob Hailu; Reid, Terry-Elinor; Zhang, Liangren; Wang, Xiang Simon

2015-01-01

Histone Deacetylases (HDACs) are an important class of drug targets for the treatment of cancers, neurodegenerative diseases and other types of diseases. Virtual screening (VS) has become fairly effective approaches for drug discovery of novel and highly selective Histone Deacetylases Inhibitors (HDACIs). To facilitate the process, we constructed the Maximal Unbiased Benchmarking Data Sets for HDACs (MUBD-HDACs) using our recently published methods that were originally developed for building unbiased benchmarking sets for ligand-based virtual screening (LBVS). The MUBD-HDACs covers all 4 Classes including Class III (Sirtuins family) and 14 HDACs isoforms, composed of 631 inhibitors and 24,609 unbiased decoys. Its ligand sets have been validated extensively as chemically diverse, while the decoy sets were shown to be property-matching with ligands and maximal unbiased in terms of “artificial enrichment” and “analogue bias”. We also conducted comparative studies with DUD-E and DEKOIS 2.0 sets against HDAC2 and HDAC8 targets, and demonstrate that our MUBD-HDACs is unique in that it can be applied unbiasedly to both LBVS and SBVS approaches. In addition, we defined a novel metric, i.e. NLBScore, to detect the “2D bias” and “LBVS favorable” effect within the benchmarking sets. In summary, MUBD-HDACs is the only comprehensive and maximal-unbiased benchmark data sets for HDACs (including Sirtuins) that is available so far. MUBD-HDACs is freely available at http://www.xswlab.org/. PMID:25633490

Histone deacetylase (HDAC)-1, -2, -4 and -6 expression in human pancreatic adenocarcinoma: associations with clinicopathological parameters, tumor proliferative capacity and patients' survival.

PubMed

Giaginis, Constantinos; Damaskos, Christos; Koutsounas, Ioannis; Zizi-Serbetzoglou, Adamantia; Tsoukalas, Nicolaos; Patsouris, Efstratios; Kouraklis, Gregorios; Theocharis, Stamatios

2015-10-26

Histone deacetylases (HDACs) have been associated with malignant tumor development and progression in humans. HDAC inhibitors (HDACIs) are currently being explored as anti-cancer agents in clinical trials. The present study aimed to evaluate the clinical significance of HDAC-1, -2, -4 and -6 protein expression in pancreatic adenocarcinoma. HDAC-1, -2, -4 and -6 protein expression was assessed immunohistochemically on 70 pancreatic adenocarcinoma tissue specimens and was statistically analyzed with clinicopathological characteristics and patients' survival. Enhanced HDAC-1 expression was significantly associated with increased tumor proliferative capacity (p = 0.0238) and borderline with the absence of lymph node metastases (p = 0.0632). Elevated HDAC-4 expression was significantly associated with the absence of organ metastases (p = 0.0453) and borderline with the absence of lymph node metastases (p = 0.0571) and tumor proliferative capacity (p = 0.0576). Enhanced HDAC-6 expression was significantly associated with earlier histopathological stage (p = 0.0115) and borderline with smaller tumor size (p = 0.0864). Pancreatic adenocarcinoma patients with enhanced HDAC-1 and -6 expression showed significantly longer survival times compared to those with low expression (p = 0.0022 and p = 0.0113, respectively), while a borderline association concerning HDAC-2 expression was noted (p = 0.0634). The present study suggested that HDACs may be implicated in pancreatic malignant disease progression, being considered of clinical utility with potential use as therapeutic targets.

Valproic acid defines a novel class of HDAC inhibitors inducing differentiation of transformed cells

PubMed Central

Göttlicher, Martin; Minucci, Saverio; Zhu, Ping; Krämer, Oliver H.; Schimpf, Annemarie; Giavara, Sabrina; Sleeman, Jonathan P.; Lo Coco, Francesco; Nervi, Clara; Pelicci, Pier Giuseppe; Heinzel, Thorsten

2001-01-01

Histone deacetylases (HDACs) play important roles in transcriptional regulation and pathogenesis of cancer. Thus, HDAC inhibitors are candidate drugs for differentiation therapy of cancer. Here, we show that the well-tolerated antiepileptic drug valproic acid is a powerful HDAC inhibitor. Valproic acid relieves HDAC-dependent transcriptional repression and causes hyperacetylation of histones in cultured cells and in vivo. Valproic acid inhibits HDAC activity in vitro, most probably by binding to the catalytic center of HDACs. Most importantly, valproic acid induces differentiation of carcinoma cells, transformed hematopoietic progenitor cells and leukemic blasts from acute myeloid leukemia patients. More over, tumor growth and metastasis formation are significantly reduced in animal experiments. Therefore, valproic acid might serve as an effective drug for cancer therapy. PMID:11742974

Histone deacetylases as regulators of inflammation and immunity.

PubMed

Shakespear, Melanie R; Halili, Maria A; Irvine, Katharine M; Fairlie, David P; Sweet, Matthew J

2011-07-01

Histone deacetylases (HDACs) remove an acetyl group from lysine residues of target proteins to regulate cellular processes. Small-molecule inhibitors of HDACs cause cellular growth arrest, differentiation and/or apoptosis, and some are used clinically as anticancer drugs. In animal models, HDAC inhibitors are therapeutic for several inflammatory diseases, but exacerbate atherosclerosis and compromise host defence. Loss of HDAC function has also been linked to chronic lung diseases in humans. These contrasting effects might reflect distinct roles for individual HDACs in immune responses. Here, we review the current understanding of innate and adaptive immune pathways that are regulated by classical HDAC enzymes. The objective is to provide a rationale for targeting (or not targeting) individual HDAC enzymes with inhibitors for future immune-related applications. Copyright © 2011 Elsevier Ltd. All rights reserved.

Novel histone deacetylase 8-selective inhibitor 1,3,4-oxadiazole-alanine hybrid induces apoptosis in breast cancer cells.

PubMed

Pidugu, Vijaya Rao; Yarla, Nagendra Sastry; Bishayee, Anupam; Kalle, Arunasree M; Satya, Alapati Krishna

2017-11-01

Identification of isoform-specific histone deacetylase inhibitors (HDACi) is a significant advantage to overcome the adverse side effects of pan-HDACi for the treatment of various diseases, including cancer. We have designed, and synthesized novel 1,3,4 oxadiazole with glycine/alanine hybrids as HDAC8-specific inhibitors and preliminary evaluation has indicated that 1,3,4 oxadiazole with alanine hybrid [(R)-2-amino-N-((5-phenyl-1,3,4-oxadiazol-2-yl)methyl)propanamide (10b)] to be a potent HDAC8 inhibitor. In the present study, the in vitro efficacy of the molecule in inhibiting the cancer cell proliferation and the underlying molecular mechanism was studied. 10b inhibited the growth of MDA-MB-231 and MCF7 breast cancer cells, with a lower IC 50 of 230 and 1000 nM, respectively, compared to K562, COLO-205 and HepG2 cells and was not cytotoxic to normal breast epithelial cells, MCF10A. 10b was specific to HDAC8 and did not affect the expression of other class I HDACs. Further, a dose-dependent increase in H3K9 acetylation levels demonstrated the HDAC-inhibitory activity of 10b in MDA-MB-231 cells. Flow cytometric analysis indicated a dose-dependent increase and decrease in the percent apoptotic cells and mitochondrial membrane potential, respectively, when treated with 10b. Immunoblot analysis showed a modulation of Bax/Bcl2 ratio with a decrease in Bcl2 expression and no change in Bax expression. 10b treatment resulted in induction of p21 and inhibition of CDK1 proteins along with cytochrome c release from mitochondria, activation of caspases-3 and -9 and cleavage of poly ADP-ribose polymerase leading to apoptotic death of MDA-MB-231 and MCF7 cells. In conclusion, our results clearly demonstrated the efficacy of 10b as an anticancer agent against breast cancer.

Potent histone deacetylase inhibitors built from trichostatin A and cyclic tetrapeptide antibiotics including trapoxin

PubMed Central

Furumai, Ryohei; Komatsu, Yasuhiko; Nishino, Norikazu; Khochbin, Saadi; Yoshida, Minoru; Horinouchi, Sueharu

2001-01-01

Trichostatin A (TSA) and trapoxin (TPX) are potent inhibitors of histone deacetylases (HDACs). TSA is proposed to block the catalytic reaction by chelating a zinc ion in the active-site pocket through its hydroxamic acid group. On the other hand, the epoxyketone is suggested to be the functional group of TPX capable of alkylating the enzyme. We synthesized a novel TPX analogue containing a hydroxamic acid instead of the epoxyketone. The hybrid compound cyclic hydroxamic acid-containing peptide (CHAP) 1 inhibited HDAC1 at low nanomolar concentrations. The HDAC1 inhibition by CHAP1 was reversible as it was by TSA, in contrast to the irreversible inhibition by TPX. CHAP with an aliphatic chain length of five, which corresponded to that of acetylated lysine, was stronger than those with other lengths. These results suggest that TPX is a substrate mimic and that the replacement of the epoxyketone with the hydroxamic acid converted TPX to an inhibitor chelating the zinc like TSA. Interestingly, HDAC6, but not HDAC1 or HDAC4, was resistant to TPX and CHAP1, whereas TSA inhibited these HDACs to a similar extent. HDAC6 inhibition by TPX at a high concentration was reversible, probably because HDAC6 is not alkylated by TPX. We further synthesized the counterparts of all known naturally occurring cyclic tetrapeptides containing the epoxyketone. HDAC1 was highly sensitive to all these CHAPs much more than HDAC6, indicating that the structure of the cyclic tetrapeptide framework affects the target enzyme specificity. These results suggest that CHAP is a unique lead to develop isoform-specific HDAC inhibitors. PMID:11134513

Histone Deacetylase Inhibitors Trichostatin A and MCP30 Relieve Benzene-Induced Hematotoxicity via Restoring Topoisomerase IIα.

PubMed

Chen, Jingjing; Zheng, Zhouyi; Chen, Yi; Li, Jiaqi; Qian, Shanhu; Shi, Yifen; Sun, Lan; Han, Yixiang; Zhang, Shenghui; Yu, Kang

2016-01-01

Dysfunction of histone acetylation inhibits topoisomerase IIα (Topo IIα), which is implicated in benzene-induced hematotoxicity in patients with chronic benzene exposure. Whether histone deacetylase (HDAC) inhibitors can relieve benzene-induced hematotoxicity remains unclear. Here we showed that hydroquinone, a main metabolite of benzene, increased the HDAC activity, decreased the Topo IIα expression and induced apoptosis in human bone marrow mononuclear cells in vitro, and treatment with two HDAC inhibitors, namely trichostatin A (TSA) or a mixture of ribosome-inactivating proteins MCP30, almost completely reversed these effects. We further established a benzene poisoning murine model by inhaling benzene vapor in a container and found that benzene poisoning decreased the expression and activity of Topo IIα, and impaired acetylation of histone H4 and H3. The analysis of regulatory factors of Topo IIα promoter found that benzene poisoning decreased the mRNA levels of SP1 and C-MYB, and increased the mRNA level of SP3. Both TSA and MCP30 significantly enhanced the acetylation of histone H3 and H4 in Topo IIα promoter and increased the expression and activity of Topo IIα in benzene poisoning mice, which contributed to relieve the symptoms of hematotoxicity. Thus, treatment with HDAC inhibitors represents an attractive approach to reduce benzene-induced hematotoxicity.

Therapeutic fetal-globin inducers reduce transcriptional repression in hemoglobinopathy erythroid progenitors through distinct mechanisms.

PubMed

Dai, Yan; Sangerman, Jose; Luo, Hong Yuan; Fucharoen, Suthat; Chui, David H K; Faller, Douglas V; Perrine, Susan P

2016-01-01

Pharmacologic augmentation of γ-globin expression sufficient to reduce anemia and clinical severity in patients with diverse hemoglobinopathies has been challenging. In studies here, representative molecules from four chemical classes, representing several distinct primary mechanisms of action, were investigated for effects on γ-globin transcriptional repressors, including components of the NuRD complex (LSD1 and HDACs 2-3), and the downstream repressor BCL11A, in erythroid progenitors from hemoglobinopathy patients. Two HDAC inhibitors (MS-275 and SB939), a short-chain fatty acid derivative (sodium dimethylbutyrate [SDMB]), and an agent identified in high-throughput screening, Benserazide, were studied. These therapeutics induced γ-globin mRNA in progenitors above same subject controls up to 20-fold, and increased F-reticulocytes up to 20%. Cellular protein levels of BCL11A, LSD-1, and KLF1 were suppressed by the compounds. Chromatin immunoprecipitation assays demonstrated a 3.6-fold reduction in LSD1 and HDAC3 occupancy in the γ-globin gene promoter with Benserazide exposure, 3-fold reduction in LSD-1 and HDAC2 occupancy in the γ-globin gene promoter with SDMB exposure, while markers of gene activation (histone H3K9 acetylation and H3K4 demethylation), were enriched 5.7-fold. These findings identify clinical-stage oral therapeutics which inhibit or displace major co-repressors of γ-globin gene transcription and may suggest a rationale for combination therapy to produce enhanced efficacy. Copyright © 2015 Elsevier Inc. All rights reserved.

Therapeutic γ-globin inducers reduce transcriptional repression in hemoglobinopathy erythroid progenitors through distinct mechanisms

PubMed Central

Dai, Yan; Sangerman, Jose; Hong, Yuan Luo; Fuchareon, Suthat; Chui, David H.K.; Faller, Douglas V.; Perrine, Susan P.

2015-01-01

Pharmacologic augmentation of γ-globin expression sufficient to reduce anemia and clinical severity in patients with diverse hemoglobinopathies has been challenging. In studies here, representative molecules from four chemical classes, representing several distinct primary mechanisms of action, were investigated for effects on γ-globin transcriptional repressors, including components of the NuRD complex (LSD1 and HDACs 2-3), and the downstream repressor BCL11A, in erythroid progenitors from hemoglobinopathy patients. Two HDAC inhibitors (MS-275 and SB939), a short-chain fatty acid derivative (sodium dimethylbutyrate [SDMB]), and an agent identified in high-throughput screening, Benserazide, were studied. These therapeutics induced γ globin mRNA in progenitors above same subject controls up to 20-fold, and increased F-reticulocytes up to 20%. Cellular protein levels of BCL11A, LSD-1, and KLF1 were suppressed by the compounds. Chromatin immunoprecipitation assays demonstrated a 3.6-fold reduction in LSD1 and HDAC3 occupancy in the γ-globin gene promoter with Benserazide exposure, 3-fold reduction in LSD-1 and HDAC2 occupancy in the γ-globin gene promoter with SDMB exposure, while markers of gene activation (histone H3K9 acetylation and H3K4 demethylation), were enriched 5.7-fold. These findings identify clinical-stage oral therapeutics which inhibit or displace major co-repressors of γ-globin gene transcription and may suggest a rationale for combination therapy to produce enhanced efficacy. PMID:26603726

HDAC5-mTORC1 Interaction in Differential Regulation of Ghrelin and Nucleobindin 2 (NUCB2)/Nesfatin-1.

PubMed

Ma, Liangxiao; Tang, Hong; Yin, Yue; Yu, Ruili; Zhao, Jing; Li, Yin; Mulholland, Michael W; Zhang, Weizhen

2015-11-01

Sodium valporate (VPA), a broad-spectrum inhibitor of histone deacetylases (HDACs), increased ghrelin whereas decreased nesfatin-1 in mice fed normal chow diet or high-fat diet. Alterations in ghrelin and nucleobindin 2/nesfatin-1 were mediated by HDAC5 but not HDAC4. Activation of mTORC1 significantly attenuated the effect of VPA on ghrelin and nesfatin-1 levels. HDAC5 coimmunoprecipitated with raptor. Inhibition of HDAC5 by VPA, trichostatin A, or siHDAC5 markedly increased acetylation of raptor Lys840 and subsequent phosphorylation of raptor Ser792, resulting in suppression of mTORC1 signaling. A raptor mutant lacking the Lys840 acetylation site showed a decrement in phosphorylation of raptor Ser792 and subsequent increase in mTORC1 signaling. These alterations were associated with reciprocal changes in ghrelin and nucleobindin 2/nesfatin-1 expression. These findings reveal HDAC5-mTORC1 signaling as a novel mechanism in the differential regulation of gastric ghrelin and nesfatin-1.

HDAC inhibitors: a 2013-2017 patent survey.

PubMed

Faria Freitas, Micaela; Cuendet, Muriel; Bertrand, Philippe

2018-04-19

Zinc-dependent histone deacetylases (HDAC) inhibitors represent an important class of biologically active compounds with four of them approved by the FDA. A wide range of molecules has been reported for applications in several human diseases.Area covered: This review covers recent efforts in the synthesis and applications of HDAC inhibitors from 2013-2017.Expert opinion: HDAC inhibitors represent an important class of biologically active compounds for single or combination therapies. The current synthetic methodologies are oriented towards selective HDAC isoforms to achieve better therapeutic effects. Among the recent patents available, most of them focus on HDAC6 selective inhibitors. Beside this search for isoform selectivity, the quest for zinc binding groups with better pharmacokinetic properties and high potency against HDACs only motivates medicinal chemists, as well as the design of inhibitors targeting HDACs and at the same time another biological target. If the major applications are for anticancer activity, one can note the emerging applications in neurological or metabolic disorders or for the stimulation of the immune system.

SAHA-based novel HDAC inhibitor design by core hopping method.

PubMed

Zang, Lan-Lan; Wang, Xue-Jiao; Li, Xiao-Bo; Wang, Shu-Qing; Xu, Wei-Ren; Xie, Xian-Bin; Cheng, Xian-Chao; Ma, Huan; Wang, Run-Ling

2014-11-01

The catalytic activity of the histone deacetylase (HDAC) is directly relevant to the pathogenesis of cancer, and HDAC inhibitors represented a promising strategy for cancer therapy. SAHA (suberoanilide hydroxamic acid), an effective HDAC inhibitor, is an anti-cancer agent against T-cell lymphoma. However, SAHA has adverse effects such as poor pharmacokinetic properties and severe toxicities in clinical use. In order to identify better HDAC inhibitors, a compound database was established by core hopping of SAHA, which was then docked into HDAC-8 (PDB ID: 1T69) active site to select a number of candidates with higher docking score and better interaction with catalytic zinc ion. Further ADMET prediction was done to give ten compounds. Molecular dynamics simulation of the representative compound 101 was performed to study the stability of HDAC8-inhibitor system. This work provided an approach to design novel high-efficiency HDAC inhibitors with better ADMET properties. Copyright © 2014 Elsevier Inc. All rights reserved.

Sensitivity of osteosarcoma cells to HDAC inhibitor AR-42 mediated apoptosis.

PubMed

Murahari, Sridhar; Jalkanen, Aimee L; Kulp, Samuel K; Chen, Ching-Shih; Modiano, Jaime F; London, Cheryl A; Kisseberth, William C

2017-01-21

Osteosarcoma (OS) is the most common primary bone tumor in both humans and dogs and is the second leading cause of cancer related deaths in children and young adults. Limb sparing surgery along with chemotherapy has been the mainstay of treatment for OS. Many patients are not cured with current therapies, presenting a real need for developing new treatments. Histone deacetylase (HDAC) inhibitors are a promising new class of anticancer agents. In this study, we investigated the activity of the novel HDAC inhibitor AR-42 in a panel of human and canine OS cell lines. The effect of AR-42 and suberoylanilide hydroxamic acid (SAHA) alone or in combination with doxorubicin on OS cell viability was assessed. Induction of histone acetylation after HDAC inhibitor treatment was confirmed by Western blotting. Drug-induced apoptosis was analyzed by FACS. Apoptosis was assessed further by measuring caspase 3/7 enzymatic activity, nucleosome fragmentation, and caspase cleavage. Effects on Akt signaling were demonstrated by assessing phosphorylation of Akt and downstream signaling molecules. AR-42 was a potent inhibitor of cell viability and induced a greater apoptotic response compared to SAHA when used at the same concentrations. Normal osteoblasts were much less sensitive. The combination of AR-42 with doxorubicin resulted in a potent inhibition of cell viability and apparent synergistic effect. Furthermore, we showed that AR-42 and SAHA induced cell death via the activation of the intrinsic mitochondrial pathway through activation of caspase 3/7. This potent apoptotic activity was associated with the greater ability of AR-42 to downregulate survival signaling through Akt. These results confirm that AR-42 is a potent inhibitor of HDAC activity and demonstrates its ability to significantly inhibit cell survival through its pleiotropic effects in both canine and human OS cells and suggests that spontaneous OS in pet dogs may be a useful large animal model for preclinical evaluation of HDAC inhibitors. HDAC inhibition in combination with standard doxorubicin treatment offers promising potential for chemotherapeutic intervention in both canine and human OS.

Exploitation of Nontraditional Crop, Yacon, in Breast Cancer Prevention Using Preclinical Rat Model

DTIC Science & Technology

2010-07-01

cellular signaling pathways – HDAC and downstream targets - AMPK/Akt-mTOR and ghrelin -IGF1 axis. Mammary carcinogenesis was initiated by injection of...reducing a gastrointestinal peptide- ghrelin that is a growth hormone secretagogue 3;4. Reduction of serum ghrelin results in decreases of IGF-1 5...tumors in rats, 2) increase butyrate and decrease ghrelin and insulin-like growth factor 1 (IGF-1) in the blood, 3) inhibit HDAC, and downregulate

Zinc Deprivation Mediates Alcohol-Induced Hepatocyte IL-8 Analog Expression in Rodents via an Epigenetic Mechanism

PubMed Central

Zhao, Yantao; Zhong, Wei; Sun, Xiuhua; Song, Zhenyuan; Clemens, Dahn L.; Kang, Y. James; McClain, Craig J.; Zhou, Zhanxiang

2011-01-01

Neutrophil infiltration caused by IL-8 production is a central mechanism in alcohol-induced hepatitis. This study was performed to examine if an epigenetic mechanism is involved in alcohol-induced IL-8 production. Mice were pair-fed an alcohol-containing liquid diet for 4 weeks. Alcohol exposure induced hepatitis as indicated by increased expression of keratinocyte-derived cytokine (mouse IL-8) and neutrophil infiltration. Alcohol exposure induced histone 3 hyperacetylation owing to inhibition of histone deacetylase (HDAC) in association with NF-κB activation. Cell culture studies showed that alcohol exposure induced IL-8 and cytokine-induced neutrophil chemoattractant-1 (CINC-1, rat IL-8) production in human VL-17A cells and rat H4IIEC3 cells, respectively, dependent on acetaldehyde production, oxidative stress, and zinc release. Zinc deprivation alone induced CINC-1 production and acted synergistically with lipopolysaccharide or tumor necrosis factor-α on CINC-1 production. Zinc deprivation induced histone 3 hyperacetylation at lysine 9 through suppression of HDAC activity. Zinc deprivation caused nuclear translocation of NF-κB, and reduced HDAC binding to NF-κB. Chromatin immunoprecipitation (ChIP) showed that zinc deprivation caused histone 3 hyperacetylation as well as increased NF-κB binding to the CINC-1 promoter. In conclusion, inactivation of HDAC caused by zinc deprivation is a novel mechanism underlying IL-8 up-regulation in alcoholic hepatitis. PMID:21708112

Effect of agomelatine on memory deficits and hippocampal gene expression induced by chronic social defeat stress in mice

PubMed Central

Martin, Vincent; Allaïli, Najib; Euvrard, Marine; Marday, Tevrasamy; Riffaud, Armance; Franc, Bernard; Mocaër, Elisabeth; Gabriel, Cecilia; Fossati, Philippe; Lehericy, Stéphane; Lanfumey, Laurence

2017-01-01

Chronic stress is known to induce not only anxiety and depressive-like phenotypes in mice but also cognitive impairments, for which the action of classical antidepressant compounds remains unsatisfactory. In this context, we investigated the effects of chronic social defeat stress (CSDS) on anxiety-, social- and cognitive-related behaviors, as well as hippocampal Bdnf, synaptic plasticity markers (PSD-95, Synaptophysin, Spinophilin, Synapsin I and MAP-2), and epigenetic modifying enzymes (MYST2, HDAC2, HDAC6, MLL3, KDM5B, DNMT3B, GADD45B) gene expression in C57BL/6J mice. CSDS for 10 days provoked long-lasting anxious-like phenotype in the open field and episodic memory deficits in the novel object recognition test. While total Bdnf mRNA level was unchanged, Bdnf exon IV, MAP-2, HDAC2, HDAC6 and MLL3 gene expression was significantly decreased in the CSDS mouse hippocampus. In CSDS mice treated 3 weeks with 50 mg/kg/d agomelatine, an antidepressant with melatonergic receptor agonist and 5-HT2C receptor antagonist properties, the anxious-like phenotype was not reversed, but the treatment successfully prevented the cognitive impairments and hippocampal gene expression modifications. Altogether, these data evidenced that, in mice, agomelatine was effective in alleviating stress-induced altered cognitive functions, possibly through a mechanism involving BDNF signaling, synaptic plasticity and epigenetic remodeling. PMID:28374847

Activatable Fluorescence Probe via Self-Immolative Intramolecular Cyclization for Histone Deacetylase Imaging in Live Cells and Tissues.

PubMed

Liu, Xianjun; Xiang, Meihao; Tong, Zongxuan; Luo, Fengyan; Chen, Wen; Liu, Feng; Wang, Fenglin; Yu, Ru-Qin; Jiang, Jian-Hui

2018-05-01

Histone deacetylases (HDACs) play essential roles in transcription regulation and are valuable theranostic targets. However, there are no activatable fluorescent probes for imaging of HDAC activity in live cells. Here, we develop for the first time a novel activatable two-photon fluorescence probe that enables in situ imaging of HDAC activity in living cells and tissues. The probe is designed by conjugating an acetyl-lysine mimic substrate to a masked aldehyde-containing fluorophore via a cyanoester linker. Upon deacetylation by HDAC, the probe undergoes a rapid self-immolative intramolecular cyclization reaction, producing a cyanohydrin intermediate that is spontaneously rapidly decomposed into the highly fluorescent aldehyde-containing two-photon fluorophore. The probe is shown to exhibit high sensitivity, high specificity, and fast response for HDAC detection in vitro. Imaging studies reveal that the probe is able to directly visualize and monitor HDAC activity in living cells. Moreover, the probe is demonstrated to have the capability of two-photon imaging of HDAC activity in deep tissue slices up to 130 μm. This activatable fluorescent probe affords a useful tool for evaluating HDAC activity and screening HDAC-targeting drugs in both live cell and tissue assays.

Histone deacetylase inhibitors: current status and overview of recent clinical trials.

PubMed

Ma, Xujun; Ezzeldin, Hany H; Diasio, Robert B

2009-10-01

Histone deacetylase (HDAC) inhibitors are a new group of anticancer agents that have a potential role in the regulation of gene expression, induction of cell death, apoptosis and cell cycle arrest of cancer cells by altering the acetylation status of chromatin and other non-histone proteins. In clinical trials, HDAC inhibitors have demonstrated promising antitumour activity as monotherapy in cutaneous T-cell lymphoma and other haematological malignancies. In solid tumours, several HDAC inhibitors have been shown to be efficacious as single agents; however, results of most clinical trials were in favour of using HDAC inhibitors either prior to the initiation of chemotherapy or in combination with other treatments. Currently, the molecular basis of response to HDAC inhibitors in patients is not fully understood. In this review, we summarize the current status of HDAC inhibitors, as single agents or in combination with other agents in different phases of clinical trials. In most of the clinical trials, HDAC inhibitors were tolerable and exerted biological or antitumor activity. HDAC inhibitors have been studied in phase I, II and III clinical trials with variable efficacy. The combination of HDAC inhibitors with other anticancer agents including epigenetic or chemotherapeutic agents demonstrated favourable clinical outcome.

Histone Deacetylases 5 and 9 Govern Responsiveness of the Heart to a Subset of Stress Signals and Play Redundant Roles in Heart Development

PubMed Central

Chang, Shurong; McKinsey, Timothy A.; Zhang, Chun Li; Richardson, James A.; Hill, Joseph A.; Olson, Eric N.

2004-01-01

The adult heart responds to stress signals by hypertrophic growth, which is often accompanied by activation of a fetal cardiac gene program and eventual cardiac demise. We showed previously that histone deacetylase 9 (HDAC9) acts as a suppressor of cardiac hypertrophy and that mice lacking HDAC9 are sensitized to cardiac stress signals. Here we report that mice lacking HDAC5 display a similar cardiac phenotype and develop profoundly enlarged hearts in response to pressure overload resulting from aortic constriction or constitutive cardiac activation of calcineurin, a transducer of cardiac stress signals. In contrast, mice lacking either HDAC5 or HDAC9 show a hypertrophic response to chronic β-adrenergic stimulation identical to that of wild-type littermates, suggesting that these HDACs modulate a specific subset of cardiac stress response pathways. We also show that compound mutant mice lacking both HDAC5 and HDAC9 show a propensity for lethal ventricular septal defects and thin-walled myocardium. These findings reveal central roles for HDACs 5 and 9 in the suppression of a subset of cardiac stress signals as well as redundant functions in the control of cardiac development. PMID:15367668

Histone deacetylases 5 and 9 govern responsiveness of the heart to a subset of stress signals and play redundant roles in heart development.

PubMed

Chang, Shurong; McKinsey, Timothy A; Zhang, Chun Li; Richardson, James A; Hill, Joseph A; Olson, Eric N

2004-10-01

The adult heart responds to stress signals by hypertrophic growth, which is often accompanied by activation of a fetal cardiac gene program and eventual cardiac demise. We showed previously that histone deacetylase 9 (HDAC9) acts as a suppressor of cardiac hypertrophy and that mice lacking HDAC9 are sensitized to cardiac stress signals. Here we report that mice lacking HDAC5 display a similar cardiac phenotype and develop profoundly enlarged hearts in response to pressure overload resulting from aortic constriction or constitutive cardiac activation of calcineurin, a transducer of cardiac stress signals. In contrast, mice lacking either HDAC5 or HDAC9 show a hypertrophic response to chronic beta-adrenergic stimulation identical to that of wild-type littermates, suggesting that these HDACs modulate a specific subset of cardiac stress response pathways. We also show that compound mutant mice lacking both HDAC5 and HDAC9 show a propensity for lethal ventricular septal defects and thin-walled myocardium. These findings reveal central roles for HDACs 5 and 9 in the suppression of a subset of cardiac stress signals as well as redundant functions in the control of cardiac development.

Histone Deacetylase Inhibitors in Clinical Studies as Templates for New Anticancer Agents

PubMed Central

Mottamal, Madhusoodanan; Zheng, Shilong; Huang, Tien L.; Wang, Guangdi

2015-01-01

Histone dacetylases (HDACs) are a group of enzymes that remove acetyl groups from histones and regulate expression of tumor suppressor genes. They are implicated in many human diseases, especially cancer, making them a promising therapeutic target for treatment of the latter by developing a wide variety of inhibitors. HDAC inhibitors interfere with HDAC activity and regulate biological events, such as cell cycle, differentiation and apoptosis in cancer cells. As a result, HDAC inhibitor-based therapies have gained much attention for cancer treatment. To date, the FDA has approved three HDAC inhibitors for cutaneous/peripheral T-cell lymphoma and many more HDAC inhibitors are in different stages of clinical development for the treatment of hematological malignancies as well as solid tumors. In the intensifying efforts to discover new, hopefully more therapeutically efficacious HDAC inhibitors, molecular modeling-based rational drug design has played an important role in identifying potential inhibitors that vary in molecular structures and properties. In this review, we summarize four major structural classes of HDAC inhibitors that are in clinical trials and different computer modeling tools available for their structural modifications as a guide to discover additional HDAC inhibitors with greater therapeutic utility. PMID:25738536

HDAC6 maintains mitochondrial connectivity under hypoxic stress by suppressing MARCH5/MITOL dependent MFN2 degradation

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kim, Hak-June; Nagano, Yoshito; Choi, Su Jin

2015-09-04

Mitochondria undergo fusion and fission in response to various metabolic stresses. Growing evidences have suggested that the morphological change of mitochondria by fusion and fission plays a critical role in protecting mitochondria from metabolic stresses. Here, we showed that hypoxia treatment could induce interaction between HDAC6 and MFN2, thus protecting mitochondrial connectivity. Mechanistically, we demonstrated that a mitochondrial ubiquitin ligase MARCH5/MITOL was responsible for hypoxia-induced MFN2 degradation in HDAC6 deficient cells. Notably, genetic abolition of HDAC6 in amyotrophic lateral sclerosis model mice showed MFN2 degradation with MARCH5 induction. Our results indicate that HDAC6 is a critical regulator of MFN2 degradationmore » by MARCH5, thus protecting mitochondrial connectivity from hypoxic stress. - Highlights: • Hypoxic stress induces the interaction between HDAC6 and MFN2. • Hypoxic stress activates MARCH5 in HDAC6 deficient cells to degrade MFN2. • HDAC6 is required to maintain mitochondrial connectivity under hypoxia. • MARCH5 is increased and promotes the degradation of MFN2 in HDAC6 KO ALS mice.« less

Kinetic and Thermodynamic Rationale for SAHA Being a Preferential Human HDAC8 Inhibitor as Compared to the Structurally Similar Ligand, TSA

PubMed Central

Singh, Raushan K.; Lall, Naveena; Leedahl, Travis S.; McGillivray, Abigail; Mandal, Tanmay; Haldar, Manas; Mallik, Sanku; Cook, Gregory; Srivastava, D.K.

2013-01-01

Of the different hydroxamate-based histone deacetylase (HDAC) inhibitors, Suberoylanilide hydroxamic acid (SAHA) has been approved by the FDA for treatment of T-cell lymphoma. Interestingly, a structurally similar inhibitor, Trichostatin A (TSA), which has a higher in vitro inhibitory-potency against HDAC8, reportedly shows a poor efficacy in clinical settings. In order to gain the molecular insight into the above discriminatory feature, we performed transient kinetic and isothermal titration calorimetric studies for the interaction of SAHA and TSA to the recombinant form of human HDAC8. The transient kinetic data revealed that the binding of both the inhibitors to the enzyme showed the biphasic profiles, which represented an initial encounter of enzyme with the inhibitor followed by the isomerization of the transient enzyme-inhibitor complexes. The temperature-dependent transient kinetic studies with the above inhibitors revealed that the bimolecular process is primarily dominated by favorable enthalpic changes, as opposed to the isomerization step; which is solely contributed by entropic changes. The standard binding-enthalpy (ΔH0) of SAHA, deduced from the transient kinetic as well as the isothermal titration calorimetric experiments, was 2–3 kcal/mol higher as compared to TSA. The experimental data presented herein suggests that SAHA serves as a preferential (target-specific/selective) HDAC8 inhibitor as compared to TSA. Arguments are presented that the detailed kinetic and thermodynamic studies may guide in the rational design of HDAC inhibitors as therapeutic agents. PMID:24079912

Calcium signals act through histone deacetylase to mediate pronephric kidney morphogenesis.

PubMed

Rothschild, Sarah C; Lee, Hunter J; Ingram, Sarah R; Mohammadi, Daniel K; Walsh, Gregory S; Tombes, Robert M

2018-06-01

Autosomal dominant polycystic kidney disease is the most common monogenetic kidney disorder and is linked to mutations in PKD1 and PKD2. PKD2, a Ca 2+ -conducting TRP channel enriched in ciliated cells and gated by extracellular signals, is necessary to activate the multifunctional Ca 2+/ calmodulin-dependent protein kinase type 2 (CaMK-II), enabling kidney morphogenesis and cilia stability. In this study, antisense morpholino oligonucleotides and pharmacological compounds were employed to investigate the roles of class II HDAC family members (HDAC 4, 5, and 6) in Zebrafish kidney development. While all three class II HDAC genes were expressed throughout the embryo during early development, HDAC5-morphant embryos exhibited anterior cysts and destabilized cloacal cilia, similar to PKD2 and CaMK-II morphants. In contrast, HDAC4-morphant embryos exhibited elongated cloacal cilia and lacked anterior kidney defects. Suppression of HDAC4 partially reversed the cilia shortening and anterior convolution defects caused by CaMK-II deficiency, whereas HDAC5 loss exacerbated these defects. EGFP-HDAC4, but not EGFP-HDAC5, translocated into the nucleus upon CaMK-II suppression in pronephric kidney cells. These results support a model by which activated CaMK-II sequesters HDAC4 in the cytosol to enable primary cilia formation and kidney morphogenesis. Developmental Dynamics 247:807-817, 2018. © 2018 Wiley Periodicals, Inc. © 2018 Wiley Periodicals, Inc.

Inside HDAC with HDAC inhibitors.

PubMed

Bertrand, Philippe

2010-06-01

Histone deacetylase inhibitors are a large group of diverse molecules intrinsically able to inhibit cell proliferation in various cancer cell lines. Their apoptotic effects have been linked to the modulation in the expression of several regulatory tumor suppressor genes caused by the modified status of histone acetylation, a key event in chromatin remodelling. As the initial histone deacetylase activity of HDAC has been extended to other proteins, the possible other biological mechanisms modified by HDAC inhibitor treatments are still to be clarified. The need for HDAC isoform selective inhibitors is an important issue to serve this goal. This review discusses the approaches proposed by several research groups working on the synthesis of HDAC inhibitors, based on modelling studies and the way these findings were used to obtain new HDAC inhibitors with possible isoform selectivity. Copyright (c) 2010 Elsevier Masson SAS. All rights reserved.

Discovery of potent HDAC inhibitors based on chlamydocin with inhibitory effects on cell migration.

PubMed

Wang, Shimiao; Li, Xiaohui; Wei, Yingdong; Xiu, Zhilong; Nishino, Norikazu

2014-03-01

The histone deacetylase (HDAC) family is a promising drug target class owing to the importance of these enzymes in a variety of cellular processes. Docking studies were conducted to identify novel HDAC inhibitors. Subtle modifications in the recognition domain were introduced into a series of chlamydocin analogues, and the resulting scaffolds were combined with various zinc binding domains. Remarkably, cyclo(L-Asu(NHOH)-L-A3mc6c-L-Phe-D-Pro, compound 1 b), with a methyl group at positions 3 or 5 on the aliphatic ring, exhibited better antiproliferative effects than trichostatin A (TSA) against MCF-7 and K562 cell lines. In addition to cell-cycle arrest and apoptosis, cell migration inhibition was observed in cells treated with compound 1 b. Subsequent western blot analysis revealed that the balance between matrix metalloproteinase 2 (MMP2) and tissue inhibitors of metalloproteinase 1 (TIMP1) determines the degree of metalloproteinase activity in MCF-7 cells, thereby regulating cell migration. The improved inhibitory activity imparted by altering the hydrophobic substitution pattern at the bulky cap group is a valuable approach in the development of novel HDAC inhibitors. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

miR-2861 as novel HDAC5 inhibitor in CHO cells enhances productivity while maintaining product quality.

PubMed

Fischer, Simon; Paul, Albert Jesuran; Wagner, Andreas; Mathias, Sven; Geiss, Melanie; Schandock, Franziska; Domnowski, Martin; Zimmermann, Jörg; Handrick, René; Hesse, Friedemann; Otte, Kerstin

2015-10-01

Histone deacetylase (HDAC) inhibitors have been exploited for years to improve recombinant protein expression in mammalian production cells. However, global HDAC inhibition is associated with negative effects on various cellular processes. microRNAs (miRNAs) have been shown to regulate gene expression in almost all eukaryotic cell types by controlling entire cellular pathways. Since miRNAs recently have gained much attention as next-generation cell engineering tool to improve Chinese hamster ovary (CHO) cell factories, we were interested if miRNAs are able to specifically repress HDAC expression in CHO cells to circumvent limitations of unspecific HDAC inhibition. We discovered a novel miRNA in CHO cells, miR-2861, which was shown to enhance productivity in various recombinant CHO cell lines. Furthermore, we demonstrate that miR-2861 might post-transcriptionally regulate HDAC5 in CHO cells. Intriguingly, siRNA-mediated HDAC5 suppression could be demonstrated to phenocopy pro-productive effects of miR-2861 in CHO cells. This supports the notion that miRNA-induced inhibition of HDAC5 may contribute to productivity enhancing effects of miR-2861. Furthermore, since product quality is fundamental to safety and functionality of biologics, we examined the effect of HDAC inhibition on critical product quality attributes. In contrast to unspecific HDAC inhibition using VPA, enforced expression of miR-2861 did not negatively influence antibody aggregation or N-glycosylation. Our findings highlight the superiority of miRNA-mediated inhibition of specific HDACs and present miR-2861 as novel cell engineering tool for improving CHO manufacturing cells. © 2015 Wiley Periodicals, Inc.

[Erythromycin restores oxidative stress-induced corticosteroid responsiveness of human THP-1 cells by up-regulating the expression of histone deacetylase 2].

PubMed

Zhang, Yang; He, Zhiyi; Sun, Xuejiao; Li, Zhanhua; Zhao, Lin; Mao, Congzheng; Huang, Dongmei; Zhang, Jianquan; Zhong, Xiaoning

2014-04-01

To investigate the effect of erythromycin (EM) on corticosteroid insensitivity of human THP-1 cells induced by cigarette smoke extract (CSE) and its mechanism. THP-1 cells were treated with EM followed by CSE stimulation. Histone deacetylase-2 (HDAC2) short interference RNA (HDAC2-siRNA) was transfected into the cells using Lipofectamine(TM); 2000. Interleukin-8 (IL-8) level in supernatants was measured by ELISA and HDAC2 expression was determined by real-time quantitative PCR (qRT-PCR) and Western blotting. The inhibition ratio of IL-8 in the EM group was significantly higher than that in the CSE group, but lower than that in the control group (P<0.05). The half-maximal inhibitory concentration of dexamethasone (IC50;-Dex) in the EM group was lower than that in the CSE group, but higher than that in the control group (P<0.05). The expression of HDAC2 protein in the EM group was higher than that in the CSE group, but lower than that in the control group (P<0.05). Besides, HDAC2 mRNA and HDAC2 protein expressions were lower in the HDAC2-siRNA group than in the scrambled oligonucleotide (SC) group. EM could reverse HDAC2 mRNA and HDAC2 protein reduction induced by HDAC2-siRNA (P<0.05). Corticosteroid sensitivity of THP-1 cells could be reduced by CSE. EM could reverse the corticosteroid insensitivity by up-regulating the expression of HDAC2 protein.

Roles of histone deacetylases in epigenetic regulation: emerging paradigms from studies with inhibitors.

PubMed

Delcuve, Geneviève P; Khan, Dilshad H; Davie, James R

2012-03-12

The zinc-dependent mammalian histone deacetylase (HDAC) family comprises 11 enzymes, which have specific and critical functions in development and tissue homeostasis. Mounting evidence points to a link between misregulated HDAC activity and many oncologic and nononcologic diseases. Thus the development of HDAC inhibitors for therapeutic treatment garners a lot of interest from academic researchers and biotechnology entrepreneurs. Numerous studies of HDAC inhibitor specificities and molecular mechanisms of action are ongoing. In one of these studies, mass spectrometry was used to characterize the affinities and selectivities of HDAC inhibitors toward native HDAC multiprotein complexes in cell extracts. Such a novel approach reproduces in vivo molecular interactions more accurately than standard studies using purified proteins or protein domains as targets and could be very useful in the isolation of inhibitors with superior clinical efficacy and decreased toxicity compared to the ones presently tested or approved. HDAC inhibitor induced-transcriptional reprogramming, believed to contribute largely to their therapeutic benefits, is achieved through various and complex mechanisms not fully understood, including histone deacetylation, transcription factor or regulator (including HDAC1) deacetylation followed by chromatin remodeling and positive or negative outcome regarding transcription initiation. Although only a very low percentage of protein-coding genes are affected by the action of HDAC inhibitors, about 40% of noncoding microRNAs are upregulated or downregulated. Moreover, a whole new world of long noncoding RNAs is emerging, revealing a new class of potential targets for HDAC inhibition. HDAC inhibitors might also regulate transcription elongation and have been shown to impinge on alternative splicing.

Characterization of the regulation and function of zinc-dependent histone deacetylases during rodent liver regeneration.

PubMed

Huang, Jiansheng; Barr, Emily; Rudnick, David A

2013-05-01

The studies reported here were undertaken to define the regulation and functional importance of zinc-dependent histone deacetylase (Zn-HDAC) activity during liver regeneration using the mouse partial hepatectomy (PH) model. The results showed that hepatic HDAC activity was significantly increased in nuclear and cytoplasmic fractions following PH. Further analyses showed isoform-specific effects of PH on HDAC messenger RNA (mRNA) and protein expression, with increased expression of the class I HDACs, 1 and 8, and class II HDAC4 in regenerating liver. Hepatic expression of (class II) HDAC5 was unchanged after PH; however, HDAC5 exhibited transient nuclear accumulation in regenerating liver. These changes in hepatic HDAC expression, subcellular localization, and activity coincided with diminished histone acetylation in regenerating liver. The significance of these events was investigated by determining the effects of suberoylanilide hydroxyamic acid (SAHA, a specific inhibitor of Zn-HDAC activity) on hepatic regeneration. The results showed that SAHA treatment suppressed the effects of PH on histone deacetylation and hepatocellular bromodeoxyuridine (BrdU) incorporation. Further examination showed that SAHA blunted hepatic expression and activation of cell cycle signals downstream of induction of cyclin D1 expression in mice subjected to PH. The data reported here demonstrate isoform-specific regulation of Zn-HDAC expression, subcellular localization, and activity in regenerating liver. These studies also indicate that HDAC activity promotes liver regeneration by regulating hepatocellular cell cycle progression at a step downstream of cyclin D1 induction. Copyright © 2012 American Association for the Study of Liver Diseases.

Structure of ‘linkerless’ hydroxamic acid inhibitor-HDAC8 complex confirms the formation of an isoform-specific subpocket

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tabackman, Alexa A.; Frankson, Rochelle; Marsan, Eric S.

Histone deacetylases (HDACs) catalyze the hydrolysis of acetylated lysine side chains in histone and non-histone proteins, and play a critical role in the regulation of many biological processes, including cell differentiation, proliferation, senescence, and apoptosis. Aberrant HDAC activity is associated with cancer, making these enzymes important targets for drug design. In general, HDAC inhibitors (HDACi) block the proliferation of tumor cells by inducing cell differentiation, cell cycle arrest, and/or apoptosis, and comprise some of the leading therapies in cancer treatments. To date, four HDACi have been FDA approved for the treatment of cancers: suberoylanilide hydroxamic acid (SAHA, Vorinostat, Zolinza®), romidepsinmore » (FK228, Istodax®), belinostat (Beleodaq®), and panobinostat (Farydak®). Most current inhibitors are pan-HDACi, and non-selectively target a number of HDAC isoforms. Six previously reported HDACi were rationally designed, however, to target a unique sub-pocket found only in HDAC8. While these inhibitors were indeed potent against HDAC8, and even demonstrated specificity for HDAC8 over HDACs 1 and 6, there were no structural data to confirm the mode of binding. Here we report the X-ray crystal structure of Compound 6 complexed with HDAC8 to 1.98 Å resolution. We also describe the use of molecular docking studies to explore the binding interactions of the other 5 related HDACi. Our studies confirm that the HDACi induce the formation of and bind in the HDAC8-specific subpocket, offering insights into isoform-specific inhibition.« less

Histone deacetylase-mediated regulation of endolysosomal pH.

PubMed

Prasad, Hari; Rao, Rajini

2018-05-04

The pH of the endolysosomal system is tightly regulated by a balance of proton pump and leak mechanisms that are critical for storage, recycling, turnover, and signaling functions in the cell. Dysregulation of endolysosomal pH has been linked to aging, amyloidogenesis, synaptic dysfunction, and various neurodegenerative disorders, including Alzheimer's disease. Therefore, understanding the mechanisms that regulate luminal pH may be key to identifying new targets for managing these disorders. Meta-analysis of yeast microarray databases revealed that nutrient-limiting conditions inhibited the histone deacetylase (HDAC) Rpd3 and thereby up-regulated transcription of the endosomal Na + /H + exchanger Nhx1, resulting in vacuolar alkalinization. Consistent with these findings, Rpd3 inhibition by the HDAC inhibitor and antifungal drug trichostatin A induced Nhx1 expression and vacuolar alkalinization. Bioinformatics analysis of Drosophila and mouse databases revealed that caloric control of the Nhx1 orthologs DmNHE3 and NHE6, respectively, is also mediated by HDACs. We show that NHE6 is a target of the transcription factor cAMP-response element-binding protein (CREB), a known regulator of cellular responses to low-nutrient conditions, providing a molecular mechanism for nutrient- and HDAC-dependent regulation of endosomal pH. Of note, pharmacological targeting of the CREB pathway to increase NHE6 expression helped regulate endosomal pH and correct defective clearance of amyloid Aβ in an apoE4 astrocyte model of Alzheimer's disease. These observations from yeast, fly, mouse, and cell culture models point to an evolutionarily conserved mechanism for HDAC-mediated regulation of endosomal NHE expression. Our insights offer new therapeutic strategies for modulation of endolysosomal pH in fungal infection and human disease. © 2018 Prasad and Rao.

In situ defect annealing of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction and a hydrothermal diamond anvil cell

DOE PAGES

Palomares, Raul I.; Tracy, Cameron L.; Zhang, Fuxiang; ...

2015-04-16

Hydrothermal diamond anvil cells (HDACs) provide facile means for coupling synchrotron Xray techniques with pressure up to 10 GPa and temperature up to 1300 K. This manuscript reports on an application of the HDAC as an ambient-pressure sample environment for performing in situ defect annealing and thermal expansion studies of swift heavy ion irradiated CeO 2 and ThO 2 using synchrotron X-ray diffraction. The advantages of the in situ HDAC technique over conventional annealing methods include: rapid temperature ramping and quench times, high-resolution measurement capability, simultaneous annealing of multiple samples, and prolonged temperature- and apparatus stability at high temperatures. Isochronalmore » annealing between 300 K and 1100 K revealed 2-stage and 1-stage defect recovery processes for irradiated CeO 2 and ThO 2, respectively; indicating that the morphology of the defects produced by swift heavy ion irradiation of these two materials differs significantly. These results suggest that electronic configuration plays a major role in both the radiation-induced defect production and high temperature defect recovery mechanisms of CeO 2 and ThO 2.« less

Can Small Chemical Modifications of Natural Pan-inhibitors Modulate the Biological Selectivity? The Case of Curcumin Prenylated Derivatives Acting as HDAC or mPGES-1 Inhibitors.

PubMed

Iranshahi, Mehrdad; Chini, Maria Giovanna; Masullo, Milena; Sahebkar, Amirhossein; Javidnia, Azita; Chitsazian Yazdi, Mahsa; Pergola, Carlo; Koeberle, Andreas; Werz, Oliver; Pizza, Cosimo; Terracciano, Stefania; Piacente, Sonia; Bifulco, Giuseppe

2015-12-24

Curcumin, or diferuloylmethane, a polyphenolic molecule isolated from the rhizome of Curcuma longa, is reported to modulate multiple molecular targets involved in cancer and inflammatory processes. On the basis of its pan-inhibitory characteristics, here we show that simple chemical modifications of the curcumin scaffold can regulate its biological selectivity. In particular, the curcumin scaffold was modified with three types of substituents at positions C-1, C-8, and/or C-8' [C5 (isopentenyl, 5-8), C10 (geranyl, 9-12), and C15 (farnesyl, 13, 14)] in order to make these molecules more selective than the parent compound toward two specific targets: histone deacetylase (HDAC) and microsomal prostaglandin E2 synthase-1 (mPGES-1). From combined in silico and in vitro analyses, three selective inhibitors by proper substitution at position 8 were revealed. Compound 13 has improved HDAC inhibitory activity and selectivity with respect to the parent compound, while 5 and 9 block the mPGES-1 enzyme. We hypothesize about the covalent interaction of curcumin, 5, and 9 with the mPGES-1 binding site.

Betaine recovers hypothalamic neural injury by inhibiting astrogliosis and inflammation in fructose-fed rats.

PubMed

Li, Jian-Mei; Ge, Chen-Xu; Xu, Min-Xuan; Wang, Wei; Yu, Rong; Fan, Chen-Yu; Kong, Ling-Dong

2015-02-01

Hypothalamic astrogliosis and inflammation cause neural injury, playing a critical role in metabolic syndrome development. This study investigated whether and how fructose caused hypothalamic astrogliosis and inflammation in vivo and in vitro. The inhibitory effects of betaine on hypothalamic neural injury, astrogliosis, and inflammation were explored to address its improvement of fructose-induced metabolic syndrome. Rats or astrocytes were exposed to fructose and then treated with betaine. Neural injury, proinflammatory markers, Toll-like receptor 4/nuclear factor-κB (TLR4/NF-κB) pathway, and histone deacetylases 3 (HDAC3) expressions were evaluated. The reduction of pro-opiomelanocortin and melanocortin 4 receptor positive neurons in fructose-fed rats was ameliorated by betaine. Moreover, fructose induced astrogliosis and proinflammatory cytokine production by increasing TLR4, MyD88 (where MyD88 is myeloid differentiation factor 88), and NF-κB expression in rat hypothalamus and astrocytes. HDAC3 overexpression preserved the prolonged inflammation in fructose-stimulated astrocytes by regulating nuclear NF-κB-dependent transcription. Betaine suppressed TLR4/NF-κB pathway activation and HDAC3 expression, contributing to its inhibition of hypothalamic astrogliosis and inflammation in animal and cell models. These findings suggest that betaine inhibits fructose-caused astrogliosis and inflammation by the suppression of TLR4/NF-κB pathway activation and HDAC3 expression to protect against hypothalamic neural injury, which, at least partly, contributes to the improvement of fructose-induced metabolic syndrome. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Increased EGFR expression induced by a novel oncogene, CUG2, confers resistance to doxorubicin through Stat1-HDAC4 signaling.

PubMed

Kaowinn, Sirichat; Jun, Seung Won; Kim, Chang Seok; Shin, Dong-Myeong; Hwang, Yoon-Hwae; Kim, Kyujung; Shin, Bosung; Kaewpiboon, Chutima; Jeong, Hyeon Hee; Koh, Sang Seok; Krämer, Oliver H; Johnston, Randal N; Chung, Young-Hwa

2017-12-01

Previously, it has been found that the cancer upregulated gene 2 (CUG2) and the epidermal growth factor receptor (EGFR) both contribute to drug resistance of cancer cells. Here, we explored whether CUG2 may exert its anticancer drug resistance by increasing the expression of EGFR. EGFR expression was assessed using Western blotting, immunofluorescence and capacitance assays in A549 lung cancer and immortalized bronchial BEAS-2B cells, respectively, stably transfected with a CUG2 expression vector (A549-CUG2; BEAS-CUG2) or an empty control vector (A549-Vec; BEAS-Vec). After siRNA-mediated EGFR, Stat1 and HDAC4 silencing, antioxidant and multidrug resistance protein and mRNA levels were assessed using Western blotting and RT-PCR. In addition, the respective cells were treated with doxorubicin after which apoptosis and reactive oxygen species (ROS) levels were measured. Stat1 acetylation was assessed by immunoprecipitation. We found that exogenous CUG2 overexpression induced EGFR upregulation in A549 and BEAS-2B cells, whereas EGFR silencing sensitized these cells to doxorubicin-induced apoptosis. In addition, we found that exogenous CUG2 overexpression reduced the formation of ROS during doxorubicin treatment by enhancing the expression of antioxidant and multidrug resistant proteins such as MnSOD, Foxo1, Foxo4, MRP2 and BCRP, whereas EGFR silencing congruently increased the levels of ROS by decreasing the expression of these proteins. We also found that EGFR silencing and its concomitant Akt, ERK, JNK and p38 MAPK inhibition resulted in a decreased Stat1 phosphorylation and, thus, a decreased activation. Since also acetylation can affect Stat1 activation via a phospho-acetyl switch, HDAC inhibition may sensitize cells to doxorubicin-induced apoptosis. Interestingly, we found that exogenous CUG2 overexpression upregulated HDAC4, but not HDAC2 or HDAC3. Conversely, we found that HDAC4 silencing sensitized the cells to doxorubicin resistance by decreasing Stat1 phosphorylation and EGFR expression, thus indicating an interplay between HDAC4, Stat1 and EGFR. Taken together, we conclude that CUG2-induced EGFR upregulation confers doxorubicin resistance to lung (cancer) cells through Stat1-HDAC4 signaling.

Histone Deacetylase (HDAC) Inhibitors - Emerging Roles in Neuronal Memory, Learning, Synaptic Plasticity and Neural Regeneration

PubMed Central

Ahmad Ganai, Shabir; Ramadoss, Mahalakshmi; Mahadevan, Vijayalakshmi

2016-01-01

Epigenetic regulation of neuronal signalling through histone acetylation dictates transcription programs that govern neuronal memory, plasticity and learning paradigms. Histone Acetyl Transferases (HATs) and Histone Deacetylases (HDACs) are antagonistic enzymes that regulate gene expression through acetylation and deacetylation of histone proteins around which DNA is wrapped inside a eukaryotic cell nucleus. The epigenetic control of HDACs and the cellular imbalance between HATs and HDACs dictate disease states and have been implicated in muscular dystrophy, loss of memory, neurodegeneration and autistic disorders. Altering gene expression profiles through inhibition of HDACs is now emerging as a powerful technique in therapy. This review presents evolving applications of HDAC inhibitors as potential drugs in neurological research and therapy. Mechanisms that govern their expression profiles in neuronal signalling, plasticity and learning will be covered. Promising and exciting possibilities of HDAC inhibitors in memory formation, fear conditioning, ischemic stroke and neural regeneration have been detailed. PMID:26487502

Histone Deacetylase (HDAC) Inhibitors - emerging roles in neuronal memory, learning, synaptic plasticity and neural regeneration.

PubMed

Ganai, Shabir Ahmad; Ramadoss, Mahalakshmi; Mahadevan, Vijayalakshmi

2016-01-01

Epigenetic regulation of neuronal signalling through histone acetylation dictates transcription programs that govern neuronal memory, plasticity and learning paradigms. Histone Acetyl Transferases (HATs) and Histone Deacetylases (HDACs) are antagonistic enzymes that regulate gene expression through acetylation and deacetylation of histone proteins around which DNA is wrapped inside a eukaryotic cell nucleus. The epigenetic control of HDACs and the cellular imbalance between HATs and HDACs dictate disease states and have been implicated in muscular dystrophy, loss of memory, neurodegeneration and autistic disorders. Altering gene expression profiles through inhibition of HDACs is now emerging as a powerful technique in therapy. This review presents evolving applications of HDAC inhibitors as potential drugs in neurological research and therapy. Mechanisms that govern their expression profiles in neuronal signalling, plasticity and learning will be covered. Promising and exciting possibilities of HDAC inhibitors in memory formation, fear conditioning, ischemic stroke and neural regeneration have been detailed.

False HDAC Inhibition by Aurone Compound.

PubMed

Itoh, Yukihiro; Suzuki, Miki; Matsui, Taiji; Ota, Yosuke; Hui, Zi; Tsubaki, Kazunori; Suzuki, Takayoshi

2016-01-01

Fluorescence assays are useful tools for estimating enzymatic activity. Their simplicity and manageability make them suitable for screening enzyme inhibitors in drug discovery studies. However, researchers need to pay attention to compounds that show auto-fluorescence and quench fluorescence, because such compounds lower the accuracy of the fluorescence assay systems by producing false-positive or negative results. In this study, we found that aurone compound 7, which has been reported as a histone deacetylase (HDAC) inhibitor, gave false-positive results. Although compound 7 was identified by an in vitro HDAC fluorescence assay, it did not show HDAC inhibitory activity in a cell-based assay, leading us to suspect its in vitro HDAC inhibitory activity. As a result of verification experiments, we found that compound 7 interferes with the HDAC fluorescence assay by quenching the HDAC fluorescence signal. Our findings underscore the faults of fluorescence assays and call attention to careless interpretation.

Inhibition mechanism of SAHA in HDAC: a revisit.

PubMed

Zhou, Jingwei; Wu, Ruibo; Luo, Hai-Bin

2015-11-28

SAHA (vorinostat, Merck) is a famous clinical drug for zinc-containing histone deacetylase (HDAC) targets against cancer and several other human disorders, whose inhibition mechanism (namely the protonation mechanism) upon binding to HDAC has been debated for more than ten years. It is very challenging to verify experimentally and is still controversial theoretically. The popular "Class-dependent" (namely "Tyr-dependent") hypothesis is that the deprotonation of SAHA is mostly regulated by the conserved Tyr308 in class I HDAC while it is replaced by the His843 in class IIa HDAC. Herein, by elaborate QM(DFT)/MM MD simulations, we exclude the prevalent "Class-dependent" mechanism and advance a novel "Metal-dependent" mechanism, where the remote second metal site (K(+) in most HDAC and Ca(2+) in HDAC2) determines the protonation of SAHA. This proof-of-principle "Metal-dependent" mechanism opens up a new avenue to utilize the second metal site for isoform-selective inhibitor design.

The Class I HDAC Inhibitor RGFP963 Enhances Consolidation of Cued Fear Extinction

ERIC Educational Resources Information Center

Bowers, Mallory E.; Xia, Bing; Carreiro, Samantha; Ressler, Kerry J.

2015-01-01

Evidence indicates that broad, nonspecific histone deacetylase (HDAC) inhibition enhances learning and memory, however, the contribution of the various HDACs to specific forms of learning is incompletely understood. Here, we show that the Class I HDAC inhibitor, RGFP963, enhances consolidation of cued fear extinction. However, RGFP966, a strong…

HDAC5-mTORC1 Interaction in Differential Regulation of Ghrelin and Nucleobindin 2 (NUCB2)/Nesfatin-1

PubMed Central

Ma, Liangxiao; Tang, Hong; Yin, Yue; Yu, Ruili; Zhao, Jing; Li, Yin

2015-01-01

Sodium valporate (VPA), a broad-spectrum inhibitor of histone deacetylases (HDACs), increased ghrelin whereas decreased nesfatin-1 in mice fed normal chow diet or high-fat diet. Alterations in ghrelin and nucleobindin 2/nesfatin-1 were mediated by HDAC5 but not HDAC4. Activation of mTORC1 significantly attenuated the effect of VPA on ghrelin and nesfatin-1 levels. HDAC5 coimmunoprecipitated with raptor. Inhibition of HDAC5 by VPA, trichostatin A, or siHDAC5 markedly increased acetylation of raptor Lys840 and subsequent phosphorylation of raptor Ser792, resulting in suppression of mTORC1 signaling. A raptor mutant lacking the Lys840 acetylation site showed a decrement in phosphorylation of raptor Ser792 and subsequent increase in mTORC1 signaling. These alterations were associated with reciprocal changes in ghrelin and nucleobindin 2/nesfatin-1 expression. These findings reveal HDAC5-mTORC1 signaling as a novel mechanism in the differential regulation of gastric ghrelin and nesfatin-1. PMID:26357899

HDAC inhibitors and immunotherapy; a double edged sword?

PubMed Central

Kroesen, Michiel; Armandari, Inna; Hoogerbrugge, Peter M.; Adema, Gosse J.

2014-01-01

Epigenetic modifications, like histone acetylation, are essential for regulating gene expression within cells. Cancer cells acquire pathological epigenetic modifications resulting in gene expression patterns that facilitate and sustain tumorigenesis. Epigenetic manipulation therefore is emerging as a novel targeted therapy for cancer. Histone Acetylases (HATs) and Histone Deacetylases (HDACs) regulate histone acetylation and hence gene expression. Histone deacetylase (HDAC) inhibitors are well known to affect cancer cell viability and biology and are already in use for the treatment of cancer patients. Immunotherapy can lead to clinical benefit in selected cancer patients, especially in patients with limited disease after tumor debulking. HDAC inhibitors can potentially synergize with immunotherapy by elimination of tumor cells. The direct effects of HDAC inhibitors on immune cell function, however, remain largely unexplored. Initial data have suggested HDAC inhibitors to be predominantly immunosuppressive, but more recent reports have challenged this view. In this review we will discuss the effects of HDAC inhibitors on tumor cells and different immune cell subsets, synergistic interactions and possible mechanisms. Finally, we will address future challenges and potential application of HDAC inhibitors in immunocombination therapy of cancer. PMID:25115382

Metabolism as a key to histone deacetylase inhibition

PubMed Central

Rajendran, Praveen; Williams, David E.; Ho, Emily; Dashwood, Roderick H.

2012-01-01

There is growing interest in the epigenetic mechanisms that are dysregulated in cancer and other human pathologies. Under this broad umbrella, modulators of histone deacetylase (HDAC) activity have gained interest as both cancer chemopreventive and therapeutic agents. Of the first generation, FDA-approved HDAC inhibitors to have progressed to clinical trials, vorinostat represents a “direct acting” compound with structural features suitable for docking into the HDAC pocket, whereas romidepsin can be considered a prodrug that undergoes reductive metabolism to generate the active intermediate (a zinc-binding thiol). It is now evident that other agents, including those in the human diet, can be converted by metabolism to intermediates that affect HDAC activity. Examples are cited of short-chain fatty acids, seleno-α-keto acids, small molecule thiols, mercapturic acid metabolites, indoles, and polyphenols. The findings are discussed in the context of putative endogenous HDAC inhibitors generated by intermediary metabolism (e.g. pyruvate), the yin–yang of HDAC inhibition versus HDAC activation, and the screening assays that might be most appropriate for discovery of novel HDAC inhibitors in the future. PMID:21599534

HDAC6 regulates the dynamics of lytic granules in cytotoxic T lymphocytes

PubMed Central

Núñez-Andrade, Norman; Iborra, Salvador; Trullo, Antonio; Moreno-Gonzalo, Olga; Calvo, Enrique; Catalán, Elena; Menasche, Gaël; Sancho, David; Vázquez, Jesús; Yao, Tso-Pang

2016-01-01

HDAC6 is a tubulin deacetylase involved in many cellular functions related to cytoskeleton dynamics including cell migration and autophagy. In addition, HDAC6 affects antigen-dependent CD4+ T cell activation. In this study, we show that HDAC6 contributes to the cytotoxic function of CD8+ T cells. Immunization studies revealed defective cytotoxic activity in vivo in the absence of HDAC6. Adoptive transfer of wild-type or Hdac6-/- CD8+ T cells to Rag1-/- mice demonstrated specific impairment in CD8+ T cell responses against vaccinia infection. Mechanistically, HDAC6-deficient cytotoxic T lymphocytes (CTLs) showed defective in vitro cytolytic activity related to altered dynamics of lytic granules, inhibited kinesin 1 – dynactin mediated terminal transport of lytic granules to the immune synapse and deficient exocytosis, but not to target cell recognition, T cell receptor (TCR) activation or interferon (IFNγ) production. Our results establish HDAC6 as an effector of the immune cytotoxic response that acts by affecting the dynamics, transport and secretion of lytic granules by CTLs. PMID:26869226

Endogenous Modulators and Pharmacological Inhibitors of Histone Deacetylases in Cancer Therapy

PubMed Central

Spiegel, Sarah; Milstien, Sheldon; Grant, Steven

2012-01-01

The class I histone deacetylases HDAC1 and HDAC2 belong to a family of 11 zinc-dependent human HDACs and are overexpressed in many cancers. Inhibitors of these HDACs now in clinical trials show activity against several types of cancers. This review is focuse on recent advances in both clinical and preclinical efforts to understand the basis for HDACi actions, with an emphasis on implications for rational combinations with conventional or other targeted agents. We will address new perspectives on the molecular mechanisms by which HDACs act and how these actions relate to cancer. We will also review new evidence demonstrating that HDACs are direct intracellular targets of the potent sphingolipid mediator sphingosine-1-phosphate (S1P), the first identified endogenous nuclear regulator of these enzymes, linking sphingolipid metabolism in the nucleus to remodeling of chromatin and epigenetic regulation of gene expression. Understanding how endogenous molecules regulate HDAC activity in vivo may facilitate the search for safer and more effective anti-cancer drugs capable of interfering with HDAC functions in a highly specific manner. PMID:21725353

HDAC6 Brain Mapping with [ 18 F]Bavarostat Enabled by a Ru-Mediated Deoxyfluorination

DOE Office of Scientific and Technical Information (OSTI.GOV)

Strebl, Martin G.; Campbell, Arthur J.; Zhao, Wen -Ning

Histone deacetylase 6 (HDAC6) function and dysregulation have been implicated in the etiology of certain cancers and more recently in central nervous system (CNS) disorders including Rett syndrome, Alzheimer’s and Parkinson’s diseases, and major depressive disorder. HDAC6-selective inhibitors have therapeutic potential, but in the CNS drug space the development of highly brain penetrant HDAC inhibitors has been a persistent challenge. Moreover, no tool exists to directly characterize HDAC6 and its related biology in the living human brain. Here, we report a highly brain penetrant HDAC6 inhibitor, Bavarostat, that exhibits excellent HDAC6 selectivity (>80-fold over all other Zn-containing HDAC paralogues), modulatesmore » tubulin acetylation selectively over histone acetylation, and has excellent brain penetrance. We further demonstrate that Bavarostat can be radiolabeled with 18F by deoxyfluorination through in situ formation of a ruthenium π-complex of the corresponding phenol precursor: the only method currently suitable for synthesis of [ 18F]Bavarostat. In conclusion, by using [ 18F]Bavarostat in a series of rodent and nonhuman primate imaging experiments, we demonstrate its utility for mapping HDAC6 in the living brain, which sets the stage for first-in-human neurochemical imaging of this important target.« less

HDAC6 Brain Mapping with [ 18 F]Bavarostat Enabled by a Ru-Mediated Deoxyfluorination

DOE PAGES

Strebl, Martin G.; Campbell, Arthur J.; Zhao, Wen -Ning; ...

2017-09-06

Histone deacetylase 6 (HDAC6) function and dysregulation have been implicated in the etiology of certain cancers and more recently in central nervous system (CNS) disorders including Rett syndrome, Alzheimer’s and Parkinson’s diseases, and major depressive disorder. HDAC6-selective inhibitors have therapeutic potential, but in the CNS drug space the development of highly brain penetrant HDAC inhibitors has been a persistent challenge. Moreover, no tool exists to directly characterize HDAC6 and its related biology in the living human brain. Here, we report a highly brain penetrant HDAC6 inhibitor, Bavarostat, that exhibits excellent HDAC6 selectivity (>80-fold over all other Zn-containing HDAC paralogues), modulatesmore » tubulin acetylation selectively over histone acetylation, and has excellent brain penetrance. We further demonstrate that Bavarostat can be radiolabeled with 18F by deoxyfluorination through in situ formation of a ruthenium π-complex of the corresponding phenol precursor: the only method currently suitable for synthesis of [ 18F]Bavarostat. In conclusion, by using [ 18F]Bavarostat in a series of rodent and nonhuman primate imaging experiments, we demonstrate its utility for mapping HDAC6 in the living brain, which sets the stage for first-in-human neurochemical imaging of this important target.« less

HDAC Inhibitors as Novel Anti-Cancer Therapeutics.

PubMed

De Souza, Cristabelle; Chatterji, Biswa Prasun

2015-01-01

Malignant growth of cells is a condition characterized by unchecked cellular proliferation, genetic instability and epigenetic dysregulation. Up-regulated HDAC (Histone Deacetylase) enzyme activity is associated with a closed chromatin assembly and subsequent gene repression, forming a characteristic feature of malignantly transformed cells. Novel therapeutics are now targeting the zinc containing HDAC enzymes for treating various types of cancers. Recently, a spate of drugs acting via HDAC inhibition have been undergoing clinical trials and several patents present exciting molecules like PCI-24781 (Abexinostat), ITF- 2357 (Givinostat); MS-275 (Entinostat), MGCD 0103 (Mocetinostat), LBH-589 (Panobinostat), FK228 (Romidepsin), PXD-101 (Belinostat) and Valproic Acid to be used as alternatives or adjuvants to traditional chemotherapeutics. However, only three HDAC inhibitors have acquired FDA approval till date. Recently, PXD-101 obtained FDA approval for the treatment of Refractory or Relapsed Peripheral T cell lymphoma. The current article reviews patents that have introduced novel molecules that are HDAC isoform specific, superior to first generation HDAC inhibitors like SAHA (Suberoylanilide Hydroxamic Acid) and TSA (Trichostatin A) and can be modified structurally to reduce toxic side effects and increase specificity. These molecules can combine the best characteristics of an ideal HDAC inhibiting drug either as monotherapy or in combinatorial therapy for cancer treatment thus, indicating promise to be included in the next generation of target specific HDAC inhibiting drugs.

Hdac6 Knock-Out Increases Tubulin Acetylation but Does Not Modify Disease Progression in the R6/2 Mouse Model of Huntington's Disease

PubMed Central

Bobrowska, Anna; Paganetti, Paolo; Matthias, Patrick; Bates, Gillian P.

2011-01-01

Huntington's disease (HD) is a progressive neurodegenerative disorder for which there is no effective disease modifying treatment. Following-on from studies in HD animal models, histone deacetylase (HDAC) inhibition has emerged as an attractive therapeutic option. In parallel, several reports have demonstrated a role for histone deacetylase 6 (HDAC6) in the modulation of the toxicity caused by the accumulation of misfolded proteins, including that of expanded polyglutamine in an N-terminal huntingtin fragment. An important role for HDAC6 in kinesin-1 dependent transport of brain-derived neurotrophic factor (BDNF) from the cortex to the striatum has also been demonstrated. To elucidate the role that HDAC6 plays in HD progression, we evaluated the effects of the genetic depletion of HDAC6 in the R6/2 mouse model of HD. Loss of HDAC6 resulted in a marked increase in tubulin acetylation throughout the brain. Despite this, there was no effect on the onset and progression of a wide range of behavioural, physiological, molecular and pathological HD-related phenotypes. We observed no change in the aggregate load or in the levels of soluble mutant exon 1 transprotein. HDAC6 genetic depletion did not affect the efficiency of BDNF transport from the cortex to the striatum. Therefore, we conclude that HDAC6 inhibition does not modify disease progression in R6/2 mice and HDAC6 should not be prioritized as a therapeutic target for HD. PMID:21677773

HDAC6 inhibition suppresses chondrosarcoma by restoring the expression of primary cilia.

PubMed

Xiang, Wei; Guo, Fengjing; Cheng, Weiting; Zhang, Jiaming; Huang, Junming; Wang, Rui; Ma, Zhongxi; Xu, Kai

2017-07-01

Chondrosarcoma is a bone tumor characterized by the secretion of a cartilage-like extracellular matrix. It has been proved to lack extracellular sensor primary cilia. This study aimed to illustrate a feasible therapeutic method for chondrosarcoma by regulating primary cilia assembly through inhibiting histone deacetylases 6 (HDAC6) activation. In order to detect the interaction between primary cilia and HDAC6 in human chondrosarcoma, Tubastatin A and small interfering RNA (siRNA) were used to inhibit the endogenous expression of HDAC6. Cell viability test and Transwell assay were applied to evaluate the effects of malignant biological properties. Primary cilia staining and related proteins were detected. The abnormal expression of HDAC6 and cilia intraflagellar transport protein 88 (IFT88) was found in chondrosarcoma tissues. The inhibition of HDAC6 could downregulate the proliferation of chondrosarcoma cells in a concentration- and time-dependent manner and suppress the invasion capacity of tumor cells. Besides, the downregulation of HDAC6 exhibited a negative effect on the proliferation of relevant proteins but a positive effect on the primary cilia-related expression of IFT88 and acetylated α-tubulin. Primary cilia restoration could be observed after HDAC6 siRNA transfection. The Aurora A-HDAC6 cascade was involved in regulating primary cilia resorption by affecting α-tubulin deacetylation and Tubastatin A could inhibit chondrosarcoma cell growth in vivo. These results indicate that restricting HDAC6 can restore primary cilia assembly accompanied with suppressed chondrosarcoma cell proliferation and invasion capacities. Thus, promoting primary cilia restoration by targeting HDAC6 may be a feasible potential therapeutic method for chondro-sarcoma treatment.

Declined Expression of Histone Deacetylase 6 Contributes to Periodontal Ligament Stem Cell Aging.

PubMed

Li, Qian; Ma, Yushi; Zhu, Yunyan; Zhang, Ting; Zhou, Yanheng

2017-01-01

Identification of regulators for aging-associated stem cell (SC) dysfunctions is a critical topic in SC biology and SC-based therapies. Periodontal ligament stem cell (PDLSC), a kind of dental mesenchymal SC with dental regeneration potential, ages with functional deterioration in both in vivo and ex vivo expansion. However, little is known about regulators for PDLSC aging. Expression changes of a potential regulator for PDLSC aging, histone deacetylase 6 (HDAC6), were evaluated within various models. Senescence-associated phenotypic and functional alternations of PDLSC in loss-of-function models for HDAC6 were examined using HDAC6-specific pharmacologic inhibitors or RNA interference-based knockdown. Involvement of p27 Kip1 in HDAC6-associated aging was demonstrated by its acetylation and stability changes along with overexpression or functional inhibition of HDAC6. Expression of HDAC6 decreased significantly in replicative senescence and induced SC aging models. Loss-of-function experiments suggested that pharmacologic inhibition of deacetylase activity of HDAC6 accelerated PDLSC senescence and impaired its SC activities, which showed reduced osteogenic differentiation and diminished migration capacities. Examination of markers for proliferative exhaustion of SCs revealed that protein level of p27 Kip1 was specifically elevated after HDAC6 inhibition. HDAC6 physically interacted with p27 Kip1 and could deacetylate p27 Kip1 . Importantly, acetylation of p27 Kip1 was negatively regulated by HDAC6, which correlated with alteration of p27 Kip1 protein levels. Data suggest that HDAC6 plays an important role in PDLSC aging, which is dependent, at least partially, on regulation of p27 Kip1 acetylation.

Evaluation of 6-([18F] fluoroacetamido)-1-hexanoic-anilide (18F-FAHA) as imaging probe in tumor xenograft mice model

NASA Astrophysics Data System (ADS)

Li, Fiona; Cho, Sung Ju; Yu, Lihai; Hudson, Robert H. E.; Luyt, Leonard G.; Pin, Christopher L.; Kovacs, Michael S.; Koropatnick, James; Lee, Ting-Yim

2016-03-01

Alteration in genetic expression is as important as gene mutation in cancer development and proliferation. Epigenetic changes affect gene expression without altering the DNA sequence. Histone deacetylase (HDAC), an enzyme facilitating histone remodelling, can lead to silencing of tumor suppressor genes making HDAC inhibitors viable anticancer drugs against tumors with increased activity of the enzyme. In this study we evaluated 18F-fluroacetamido-1-hexanoicanilide (18F-FAHA), an artificial HDAC substrate, as imaging probe of HDAC activity of human tumor xenografts in immunocompromised host mice. Human breast and melanoma cell lines, MDA-MB-468 and MDA-MB-435 respectively, known to overexpress HDAC activity were xenografted into immunocompromised mice and HDAC activity was imaged using 18F-FAHA. The melanoma group was treated with saline, SAHA (suberoylanilide hydroxamic acid, an approved anticancer HDAC inhibitor) in DMSO, or DMSO as positive control. Tracer kinetic modelling and SUV were used to estimate HDAC activity from dynamic PET data. Both breast tumor and melanoma group showed great variability in binding rate constant (BRC) of 18F-FAHA suggesting highly variable inter- and intra-tumoral HDAC activity. For the SAHA treated melanoma group, HDAC activity, as monitored by BRC of 18F-FAHA, decreased more than the two (positive and negative) control groups but not tumor growth. Our preliminary study showed that noninvasive PET imaging with 18F-FAHA has the potential to identify patients for whom treatment with HDAC inhibitors are appropriate, to assess the effectiveness of that treatment as an early marker of target reduction, and also eliminate the need for invasive tissue biopsy to individualize treatment.

Histone deacetylase and GATA-binding factor 6 regulate arterial remodeling in angiotensin II-induced hypertension.

PubMed

Kim, Gwi Ran; Cho, Soo-Na; Kim, Hyung-Seok; Yu, Seon Young; Choi, Sin Young; Ryu, Yuhee; Lin, Ming Quan; Jin, Li; Kee, Hae Jin; Jeong, Myung Ho

2016-11-01

Histone deacetylase (HDAC) inhibitors have been reported to improve essential and secondary hypertension. However, the specific HDAC that might serve as a therapeutic target and the associated upstream and downstream molecules involved in regulating hypertension remain unknown. Our study was aimed at investigating whether a selective inhibitor of class II HDAC (MC1568) modulates hypertension, elucidating the underlying mechanism. Hypertension was established by administering angiotensin II (Ang II) to mice before treatment with MC1568. SBP was measured. Treatment with MC1568 reduced elevated SBP; attenuated arterial remodeling in the kidney's small arteries and thoracic aorta; and inhibited cell cycle regulatory gene expression, vascular smooth muscle cell (VSMC) proliferation, DNA synthesis, and VSMC hypertrophy in vivo and in vitro. Ang II enhanced the expression of phosphorylated HDAC4 and GATA-binding factor 6 (GATA6) proteins, which were specifically localized in the cytoplasm of cells in the arteries of kidneys and in aortas. Forced expression and knockdown of HDAC4 increased and decreased, respectively, the proliferation and expression of cell cycle genes in VSMCs. GATA6, a newly described binding partner of HDAC4, markedly enhanced the size and number of VSMCs. Calcium/calmodulin-dependent kinase IIα (CaMKIIα), but not HDAC4, translocated from the nucleus to the cytoplasm in response to Ang II. CaMKIIα and protein kinase D1 were associated with VSMC hypertrophy and hyperplasia via direct interaction with HDAC4. MC1568 treatment weakened the association between HDAC4 and CaMKIIα. These results suggest that class II HDAC inhibition attenuates hypertension by negatively regulating VSMC hypertrophy and hyperplasia via the CaMKIIα/protein kinase D1/HDAC4/GATA6 pathway.

Combination of proteasome and class I HDAC inhibitors induces apoptosis of NPC cells through an HDAC6-independent ER stress-induced mechanism.

PubMed

Hui, Kwai Fung; Chiang, Alan K S

2014-12-15

The current paradigm stipulates that inhibition of histone deacetylase (HDAC) 6 is essential for the combinatorial effect of proteasome and HDAC inhibitors for the treatment of cancers. Our study aims to investigate the effect of combining different class I HDAC inhibitors (without HDAC6 action) with a proteasome inhibitor on apoptosis of nasopharyngeal carcinoma (NPC). We found that combination of a proteasome inhibitor, bortezomib, and several class I HDAC inhibitors, including MS-275, apicidin and romidepsin, potently induced killing of NPC cells both in vitro and in vivo. Among the drug pairs, combination of bortezomib and romidepsin (bort/romidepsin) was the most potent and could induce apoptosis at low nanomolar concentrations. The apoptosis of NPC cells was reactive oxygen species (ROS)- and caspase-dependent but was independent of HDAC6 inhibition. Of note, bort/romidepsin might directly suppress the formation of aggresome through the downregulation of c-myc. In addition, two markers of endoplasmic reticulum (ER) stress-induced apoptosis, ATF-4 and CHOP/GADD153, were upregulated, whereas a specific inhibitor of caspase-4 (an initiator of ER stress-induced apoptosis) could suppress the apoptosis. When ROS level in the NPC cells was reduced to the untreated level, ER stress-induced caspase activation was abrogated. Collectively, our data demonstrate a model of synergism between proteasome and class I HDAC inhibitors in the induction of ROS-dependent ER stress-induced apoptosis of NPC cells, independent of HDAC6 inhibition, and provide the rationale to combine the more specific and potent class I HDAC inhibitors with proteasome inhibitors for the treatment of cancers. © 2014 UICC.

Pharmacokinetic optimization of class-selective histone deacetylase inhibitors and identification of associated candidate predictive biomarkers of hepatocellular carcinoma tumor response.

PubMed

Wong, Jason C; Tang, Guozhi; Wu, Xihan; Liang, Chungen; Zhang, Zhenshan; Guo, Lei; Peng, Zhenghong; Zhang, Weixing; Lin, Xianfeng; Wang, Zhanguo; Mei, Jianghua; Chen, Junli; Pan, Song; Zhang, Nan; Liu, Yongfu; Zhou, Mingwei; Feng, Lichun; Zhao, Weili; Li, Shijie; Zhang, Chao; Zhang, Meifang; Rong, Yiping; Jin, Tai-Guang; Zhang, Xiongwen; Ren, Shuang; Ji, Ying; Zhao, Rong; She, Jin; Ren, Yi; Xu, Chunping; Chen, Dawei; Cai, Jie; Shan, Song; Pan, Desi; Ning, Zhiqiang; Lu, Xianping; Chen, Taiping; He, Yun; Chen, Li

2012-10-25

Herein, we describe the pharmacokinetic optimization of a series of class-selective histone deacetylase (HDAC) inhibitors and the subsequent identification of candidate predictive biomarkers of hepatocellular carcinoma (HCC) tumor response for our clinical lead using patient-derived HCC tumor xenograft models. Through a combination of conformational constraint and scaffold hopping, we lowered the in vivo clearance (CL) and significantly improved the bioavailability (F) and exposure (AUC) of our HDAC inhibitors while maintaining selectivity toward the class I HDAC family with particular potency against HDAC1, resulting in clinical lead 5 (HDAC1 IC₅₀ = 60 nM, mouse CL = 39 mL/min/kg, mouse F = 100%, mouse AUC after single oral dose at 10 mg/kg = 6316 h·ng/mL). We then evaluated 5 in a biomarker discovery pilot study using patient-derived tumor xenograft models, wherein two out of the three models responded to treatment. By comparing tumor response status to compound tumor exposure, induction of acetylated histone H3, candidate gene expression changes, and promoter DNA methylation status from all three models at various time points, we identified preliminary candidate response prediction biomarkers that warrant further validation in a larger cohort of patient-derived tumor models and through confirmatory functional studies.

Sex-switching of the Drosophila brain by two antagonistic chromatin factors

PubMed Central

Ito, Hiroki; Sato, Kosei; Yamamoto, Daisuke

2013-01-01

In Drosophila melanogaster, the fruitless (fru) gene encoding BTB-Zn-finger transcription factors organizes male sexual behavior by controlling the development of sexually dimorphic neuronal circuitry. However, the molecular mechanism by which fru controls the sexual fate of neurons has been unknown. Our recent study represents a first step toward clarification of this mechanism. We have shown that: (1) Fru forms a complex with the transcriptional cofactor Bonus (Bon), which recruits either of two chromatin regulators, Histone deacetylase 1 (HDAC1) or Heterochromatin protein 1a (HP1a), to Fru-target sites; (2) the Fru-Bon complex has a masculinizing effect on single sexually-dimorphic neurons when it recruits HDAC1, whereas it has a demasculinizing effect when it recruits HP1a; (3) HDAC1 or HP1a thus recruited to Fru-target sites determines the sexual fate of single neurons in an all-or-none manner, as manipulations of HDAC1 or HP1a expression levels affect the proportion of male-typical neurons and female-typical neurons without producing neurons of intersexual characteristics. Here, we hypothesize that chromatin landscape changes induced by ecdysone surges direct the HDAC1- or HP1a-containing Fru complex to distinct targets, thereby allowing them to switch the neuronal sexual fate in the brain. PMID:23519136

The Histone Deacetylase Inhibitor Trichostatin A Promotes Totipotency in the Male Gametophyte[W

PubMed Central

Li, Hui; Soriano, Mercedes; Cordewener, Jan; Muiño, Jose M.; Riksen, Tjitske; Fukuoka, Hiroyuki; Angenent, Gerco C.; Boutilier, Kim

2014-01-01

The haploid male gametophyte, the pollen grain, is a terminally differentiated structure whose function ends at fertilization. Plant breeding and propagation widely use haploid embryo production from in vitro–cultured male gametophytes, but this technique remains poorly understood at the mechanistic level. Here, we show that histone deacetylases (HDACs) regulate the switch to haploid embryogenesis. Blocking HDAC activity with trichostatin A (TSA) in cultured male gametophytes of Brassica napus leads to a large increase in the proportion of cells that switch from pollen to embryogenic growth. Embryogenic growth is enhanced by, but not dependent on, the high-temperature stress that is normally used to induce haploid embryogenesis in B. napus. The male gametophyte of Arabidopsis thaliana, which is recalcitrant to haploid embryo development in culture, also forms embryogenic cell clusters after TSA treatment. Genetic analysis suggests that the HDAC protein HDA17 plays a role in this process. TSA treatment of male gametophytes is associated with the hyperacetylation of histones H3 and H4. We propose that the totipotency of the male gametophyte is kept in check by an HDAC-dependent mechanism and that the stress treatments used to induce haploid embryo development in culture impinge on this HDAC-dependent pathway. PMID:24464291

Sodium Valproate, a Histone Deacetylase Inhibitor, Is Associated With Reduced Stroke Risk After Previous Ischemic Stroke or Transient Ischemic Attack

PubMed Central

Brookes, Rebecca L.; Crichton, Siobhan; Wolfe, Charles D.A.; Yi, Qilong; Li, Linxin; Hankey, Graeme J.; Rothwell, Peter M.

2018-01-01

Background and Purpose— A variant in the histone deacetylase 9 (HDAC9) gene is associated with large artery stroke. Therefore, inhibiting HDAC9 might offer a novel secondary preventative treatment for ischemic stroke. The antiepileptic drug sodium valproate (SVA) is a nonspecific inhibitor of HDAC9. We tested whether SVA therapy given after ischemic stroke was associated with reduced recurrent stroke rate. Methods— Data were pooled from 3 prospective studies recruiting patients with previous stroke or transient ischemic attack and long-term follow-up: the South London Stroke Register, The Vitamins to Prevent Stroke Study, and the Oxford Vascular Study. Patients receiving SVA were compared with patients who received antiepileptic drugs other than SVA using survival analysis and Cox Regression. Results— A total of 11 949 patients with confirmed ischemic event were included. Recurrent stroke rate was lower in patient taking SVA (17 of 168) than other antiepileptic drugs (105 of 530; log-rank survival analysis P=0.002). On Cox regression, controlling for potential cofounders, SVA remained associated with reduced stroke (hazard ratio=0.44; 95% confidence interval: 0.3–0.7; P=0.002). A similar result was obtained when patients taking SVA were compared with all cases not taking SVA (Cox regression, hazard ratio=0.47; 95% confidence interval: 0.29–0.77; P=0.003). Conclusions— These results suggest that exposure to SVA, an inhibitor of HDAC, may be associated with a lower recurrent stroke risk although we cannot exclude residual confounding in this study design. This supports the hypothesis that HDAC9 is important in the ischemic stroke pathogenesis and that its inhibition, by SVA or a more specific HDAC9 inhibitor, is worthy of evaluation as a treatment to prevent recurrent ischemic stroke. PMID:29247141

Histone deacetylase inhibitors suppress RSV infection and alleviate virus-induced airway inflammation

PubMed Central

Feng, Qiuqin; Su, Zhonglan; Song, Shiyu; Xu, Hui; Zhang, Bin; Yi, Long; Tian, Man; Wang, Hongwei

2016-01-01

Respiratory syncytial virus (RSV) is the leading cause of lower respiratory tract infections in infants and young children. However, the majority of RSV-infected patients only show mild symptoms. Different severities of infection and responses among the RSV-infected population indicate that epigenetic regulation as well as personal genetic background may affect RSV infectivity. Histone deacetylase (HDAC) is an important epigenetic regulator in lung diseases. The present study aimed to explore the possible connection between HDAC expression and RSV-induced lung inflammation. To address this question, RSV-infected airway epithelial cells (BEAS-2B) were prepared and a mouse model of RSV infection was established, and then treated with various concentrations of HDAC inhibitors (HDACis), namely trichostatin A (TSA) and suberoylanilide hydroxamic acid (SAHA). Viral replication and markers of virus-induced airway inflammation or oxidative stress were assessed. The activation of the nuclear factor-κB (NF-κB), cyclo-oxygenase-2 (COX-2), mitogen-activated protein kinase (MAPK) and signal transducer and activator of transcription 3 (STAT3) signaling pathways was evaluated by western blot analysis. Our results showed that RSV infection in airway epithelial cells (AECs) significantly decreased histone acetylation levels by altering HDAC2 expression. The treatment of RSV-infected AECs with HDACis significantly restricted RSV replication by upregulating the interferon-α (IFN-α) related signaling pathways. The treatment of RSV-infected AECs with HDACis also significantly inhibited RSV-induced pro-inflammatory cytokine release [interleukin (IL)-6 and IL-8] and oxidative stress-related molecule production [malondialdehyde (MDA), and nitrogen monoxide (NO)]. The activation of NF-κB, COX-2, MAPK and Stat3, which orchestrate pro-inflammatory gene expression and oxidative stress injury, was also significantly inhibited. Our in vivo study using a mouse model of RSV infection validated these results. Treatment with HDACis alleviated airway inflammation and reduced in vivo RSV replication. Our data demonstrated that RSV reduced histone acetylation by enhancing HDAC2 expression. Treatment with HDACis (TSA/SAHA) significantly inhibited RSV replication and decreased RSV-induced airway inflammation and oxidative stress. Therefore, the inhibition of HDACs represents a novel therapeutic approach in modulating RSV-induced lung disease. PMID:27460781

Azetidinones as zinc-binding groups to design selective HDAC8 inhibitors.

PubMed

Galletti, Paola; Quintavalla, Arianna; Ventrici, Caterina; Giannini, Giuseppe; Cabri, Walter; Penco, Sergio; Gallo, Grazia; Vincenti, Silvia; Giacomini, Daria

2009-12-01

2-Azetidinones, commonly known as beta-lactams, are well-known heterocyclic compounds. Herein we described the synthesis and biological evaluation of a series of novel beta-lactams. In vitro inhibition assays against HDAC isoforms showed an interesting isoform-selectivity of these compounds towards HDAC6 and HDAC8. The isoform selectivity changed in response to modification of the azetidinone-ring nitrogen atom substituent. The presence of an N-thiomethyl group is a prerequisite for the activity of these compounds in the micromolar range towards HDAC8.

Multimodal HDAC Inhibitors with Improved Anticancer Activity.

PubMed

Schobert, Rainer; Biersack, Bernhard

2018-01-01

Histone deacetylases (HDACs) play a significant role in the proliferation and dissemination of cancer and represent promising epigenetic drug targets. The HDAC inhibitor vorinostat featuring a zinc-binding hydroxamate fragment was already clinically approved. However, HDAC inhibitors containing hydroxamic acids are often hampered by acquired or intrinsic drug resistance and may lead to enhanced tumor aggressiveness. In order to overcome these drawbacks of hydroxamate HDAC inhibitors, a series of multimodal derivatives of this compound class, including such with different zinc-binding groups, was recently developed and showed promising anticancer activity. This review provides an overview of the chemistry and pleiotropic anticancer modes of action of these conceptually new HDAC inhibitors. Copyright© Bentham Science Publishers; For any queries, please email at epub@benthamscience.org.

Contractile actin cables induced by Bacillus anthracis lethal toxin depend on the histone acetylation machinery.

PubMed

Rolando, Monica; Stefani, Caroline; Doye, Anne; Acosta, Maria I; Visvikis, Orane; Yevick, Hannah G; Buchrieser, Carmen; Mettouchi, Amel; Bassereau, Patricia; Lemichez, Emmanuel

2015-10-01

It remains a challenge to decode the molecular basis of the long-term actin cytoskeleton rearrangements that are governed by the reprogramming of gene expression. Bacillus anthracis lethal toxin (LT) inhibits mitogen-activated protein kinase (MAPK) signaling, thereby modulating gene expression, with major consequences for actin cytoskeleton organization and the loss of endothelial barrier function. Using a laser ablation approach, we characterized the contractile and tensile mechanical properties of LT-induced stress fibers. These actin cables resist pulling forces that are transmitted at cell-matrix interfaces and at cell-cell discontinuous adherens junctions. We report that treating the cells with trichostatin A (TSA), a broad range inhibitor of histone deacetylases (HDACs), or with MS-275, which targets HDAC1, 2 and 3, induces stress fibers. LT decreased the cellular levels of HDAC1, 2 and 3 and reduced the global HDAC activity in the nucleus. Both the LT and TSA treatments induced Rnd3 expression, which is required for the LT-mediated induction of actin stress fibers. Furthermore, we reveal that treating the LT-intoxicated cells with garcinol, an inhibitor of histone acetyl-transferases (HATs), disrupts the stress fibers and limits the monolayer barrier dysfunctions. These data demonstrate the importance of modulating the flux of protein acetylation in order to control actin cytoskeleton organization and the endothelial cell monolayer barrier. © 2015 Wiley Periodicals, Inc.

Histone Deacetylase Inhibitors Trichostatin A and MCP30 Relieve Benzene-Induced Hematotoxicity via Restoring Topoisomerase IIα

PubMed Central

Chen, Yi; Li, Jiaqi; Qian, Shanhu; Shi, Yifen; Sun, Lan; Han, Yixiang; Zhang, Shenghui; Yu, Kang

2016-01-01

Dysfunction of histone acetylation inhibits topoisomerase IIα (Topo IIα), which is implicated in benzene-induced hematotoxicity in patients with chronic benzene exposure. Whether histone deacetylase (HDAC) inhibitors can relieve benzene-induced hematotoxicity remains unclear. Here we showed that hydroquinone, a main metabolite of benzene, increased the HDAC activity, decreased the Topo IIα expression and induced apoptosis in human bone marrow mononuclear cells in vitro, and treatment with two HDAC inhibitors, namely trichostatin A (TSA) or a mixture of ribosome-inactivating proteins MCP30, almost completely reversed these effects. We further established a benzene poisoning murine model by inhaling benzene vapor in a container and found that benzene poisoning decreased the expression and activity of Topo IIα, and impaired acetylation of histone H4 and H3. The analysis of regulatory factors of Topo IIα promoter found that benzene poisoning decreased the mRNA levels of SP1 and C-MYB, and increased the mRNA level of SP3. Both TSA and MCP30 significantly enhanced the acetylation of histone H3 and H4 in Topo IIα promoter and increased the expression and activity of Topo IIα in benzene poisoning mice, which contributed to relieve the symptoms of hematotoxicity. Thus, treatment with HDAC inhibitors represents an attractive approach to reduce benzene-induced hematotoxicity. PMID:27058040

First-in-human study of the toxicity, pharmacokinetics, and pharmacodynamics of CG200745, a pan-HDAC inhibitor, in patients with refractory solid malignancies.

PubMed

Kim, Kyu-pyo; Park, Seong Joon; Kim, Jeong-Eun; Hong, Yong Sang; Lee, Jae-Lyun; Bae, Kyun-Seop; Cha, Hyunju; Kwon, Sool-Ki; Ro, Seonggu; Cho, JoongMyung; Kim, Tae Won

2015-10-01

The aim of the present study was to assess the safety, maximum tolerated dose (MTD), pharmacokinetics, pharmacodynamics, and efficacy of single and multiple doses of intravenous CG200745, a novel histone deacetylase (HDAC) inhibitor, in patients with advanced solid malignancies. Two to six patients received intravenous CG200745 according to the 2 + 4 dose-escalating method. This first-in-human trial was comprised of two parts: Part 1 was a single ascending dose, and Part 2 was multiple ascending doses weekly for 3 weeks, and then 1 week off. For the first cycle, pharmacokinetic sampling for CG200745 and pharmacodynamic sampling for acetylated histone H4 in peripheral blood mononuclear cells (PBMCs) were performed on day 1 for Part 1 and on days 1 and 15 for Part 2. Examination of acetylated histone H4 in pre- and post-biopsy samples was performed in accessible patients. In all, 28 patients were treated at 13 dose levels (1.8-250 mg/m(2)) and received a total of 71 cycles of CG200745. Hematologic toxicities included grade 3/4 neutropenia (22.2 %) that did not last a week and non-hematologic toxicities included fatigue (22.2 %) and anorexia (16.7 %) that did not exceed grade 2. No dose-limiting toxic effects were noted. Dose proportionality was observed for both the maximum concentration and area under the curve. The elimination half-life was 5.67 ± 2.69 h (mean ± standard deviation). An increase in PBMC acetylated histone H4 was observed at dose levels up to 51 mg/m(2), which plateaued at higher dose levels. At 24 h, 75 % of patients (6/8) showed higher relative acetylation in tumor tissue compared to PBMCs. Although there was no partial or complete response, 57.1 % of patients (16/28) had stable disease that lasted at least 6 weeks. CG200745 can be safely administered at effective dose levels that inhibit HDAC in PBMCs and tumor tissue. Although MTD was not reached, further escalation was not performed because acetylated histone H4 plateaued at dose levels higher than 51 mg/m(2). Additional phase II trials are recommended at 250 mg/m(2).

Zinc deprivation mediates alcohol-induced hepatocyte IL-8 analog expression in rodents via an epigenetic mechanism.

PubMed

Zhao, Yantao; Zhong, Wei; Sun, Xiuhua; Song, Zhenyuan; Clemens, Dahn L; Kang, Y James; McClain, Craig J; Zhou, Zhanxiang

2011-08-01

Neutrophil infiltration caused by IL-8 production is a central mechanism in alcohol-induced hepatitis. This study was performed to examine if an epigenetic mechanism is involved in alcohol-induced IL-8 production. Mice were pair-fed an alcohol-containing liquid diet for 4 weeks. Alcohol exposure induced hepatitis as indicated by increased expression of keratinocyte-derived cytokine (mouse IL-8) and neutrophil infiltration. Alcohol exposure induced histone 3 hyperacetylation owing to inhibition of histone deacetylase (HDAC) in association with NF-κB activation. Cell culture studies showed that alcohol exposure induced IL-8 and cytokine-induced neutrophil chemoattractant-1 (CINC-1, rat IL-8) production in human VL-17A cells and rat H4IIEC3 cells, respectively, dependent on acetaldehyde production, oxidative stress, and zinc release. Zinc deprivation alone induced CINC-1 production and acted synergistically with lipopolysaccharide or tumor necrosis factor-α on CINC-1 production. Zinc deprivation induced histone 3 hyperacetylation at lysine 9 through suppression of HDAC activity. Zinc deprivation caused nuclear translocation of NF-κB, and reduced HDAC binding to NF-κB. Chromatin immunoprecipitation (ChIP) showed that zinc deprivation caused histone 3 hyperacetylation as well as increased NF-κB binding to the CINC-1 promoter. In conclusion, inactivation of HDAC caused by zinc deprivation is a novel mechanism underlying IL-8 up-regulation in alcoholic hepatitis. Copyright © 2011 American Society for Investigative Pathology. Published by Elsevier Inc. All rights reserved.

MutSβ and histone deacetylase complexes promote expansions of trinucleotide repeats in human cells

PubMed Central

Gannon, Anne-Marie M.; Frizzell, Aisling; Healy, Evan; Lahue, Robert S.

2012-01-01

Trinucleotide repeat (TNR) expansions cause at least 17 heritable neurological diseases, including Huntington’s disease. Expansions are thought to arise from abnormal processing of TNR DNA by specific trans-acting proteins. For example, the DNA repair complex MutSβ (MSH2–MSH3 heterodimer) is required in mice for on-going expansions of long, disease-causing alleles. A distinctive feature of TNR expansions is a threshold effect, a narrow range of repeat units (∼30–40 in humans) at which mutation frequency rises dramatically and disease can initiate. The goal of this study was to identify factors that promote expansion of threshold-length CTG•CAG repeats in a human astrocytic cell line. siRNA knockdown of the MutSβ subunits MSH2 or MSH3 impeded expansions of threshold-length repeats, while knockdown of the MutSα subunit MSH6 had no effect. Chromatin immunoprecipitation experiments indicated that MutSβ, but not MutSα, was enriched at the TNR. These findings imply a direct role for MutSβ in promoting expansion of threshold-length CTG•CAG tracts. We identified the class II deacetylase HDAC5 as a novel promoting factor for expansions, joining the class I deacetylase HDAC3 that was previously identified. Double knockdowns were consistent with the possibility that MutSβ, HDAC3 and HDAC5 act through a common pathway to promote expansions of threshold-length TNRs. PMID:22941650

Molecular mechanisms underlying the antitumor activity of (E)-N-hydroxy-3-(1-(4-methoxyphenylsulfonyl)-1,2,3,4-tetrahydroquinolin-6-yl)acrylamide in human colorectal cancer cells in vitro and in vivo

PubMed Central

Chen, Chun-Han; Lee, Chia-Hwa; Liou, Jing-Ping; Teng, Che-Ming; Pan, Shiow-Lin

2015-01-01

Upregulation of class I histone deacetylases (HDAC) correlates with poor prognosis in colorectal cancer (CRC) patients. Previous study revealed that (E)-N-hydroxy-3-(1-(4-methoxyphenylsulfonyl)-1,2,3,4-tetrahydroquinolin-6-yl)acrylamide (Compound 11) is a potent and selective class I HDAC inhibitor, exhibited significant anti-proliferative activity in various human cancer cell lines. In current study, we demonstrated that compound 11 exhibited significant anti-proliferative and cytotoxic activity in CRC cells. Notably, compound 11 was less potent than SAHA in inhibiting HDAC6 as evident from the lower expression of acetyl-α-tubulin, suggesting higher selectivity for class I HDACs. Mechanistically, compound 11 induced cell-cycle arrest at the G2/M phase, activated both intrinsic- and extrinsic-apoptotic pathways, altered the expression of Bcl-2 family proteins and exerted a potent inhibitory effect on survival signals (p-Akt, p-ERK) in CRC cells. Moreover, we provide evidence that compound 11 suppressed motility, decreased mesenchymal markers (N-cadherin and vimentin) and increased epithelial marker (E-cadherin) through down-regulation of Akt. The anti-tumor activity and underlying molecular mechanisms of compound 11 were further confirmed using the HCT116 xenograft model in vivo. Our findings provide evidence of the significant anti-tumor activity of compound 11 in a preclinical model, supporting its potential as a novel therapeutic agent for CRC. PMID:26462017

Synthesis and biological evaluation of largazole zinc-binding group analogs.

PubMed

Kim, Bumki; Ratnayake, Ranjala; Lee, Hyunji; Shi, Guqin; Zeller, Sabrina L; Li, Chenglong; Luesch, Hendrik; Hong, Jiyong

2017-06-15

Histone acetylation is an extensively investigated post-translational modification that plays an important role as an epigenetic regulator. It is controlled by histone acetyl transferases (HATs) and histone deacetylases (HDACs). The overexpression of HDACs and consequent hypoacetylation of histones have been observed in a variety of different diseases, leading to a recent focus of HDACs as attractive drug targets. The natural product largazole is one of the most potent natural HDAC inhibitors discovered so far and a number of largazole analogs have been prepared to define structural requirements for its HDAC inhibitory activity. However, previous structure-activity relationship studies have heavily investigated the macrocycle region of largazole, while there have been only limited efforts to probe the effect of various zinc-binding groups (ZBGs) on HDAC inhibition. Herein, we prepared a series of largazole analogs with various ZBGs and evaluated their HDAC inhibition and cytotoxicity. While none of the analogs tested were as potent or selective as largazole, the Zn 2+ -binding affinity of each ZBG correlated with HDAC inhibition and cytotoxicity. We expect that our findings will aid in building a deeper understanding of the role of ZBGs in HDAC inhibition as well as provide an important basis for the future development of new largazole analogs with non-thiol ZBGs as novel therapeutics for cancer. Copyright © 2017 Elsevier Ltd. All rights reserved.

HDAC inhibitors, MS-275 and salermide, potentiates the anticancer effect of EF24 in human pancreatic cancer cells.

PubMed

Yar Saglam, Atiye Seda; Yilmaz, Akin; Onen, Hacer Ilke; Alp, Ebru; Kayhan, Handan; Ekmekci, Abdullah

2016-01-01

Histone deacetylases (HDACs) play a major role in the regulation of chromatin structure and gene expression by changing acetylation status of histone and non-histone proteins. MS-275 (entinostat, MS) is a well-known benzamide-based HDACI and Salermide (SAL), a reverse amide compound HDACI, have antiproliferative effects on several human cancer cells. In this study, we aimed to investigate the effects of HDACIs (MS and SAL) alone and/or combined use with EF24 (EF), a novel synthetic curcumin analog, on human pancreatic cancer cell line (BxPC-3). In vitro, BxPC-3 cells were exposed to varying concentrations of MS, SAL with or without EF, and their effects on cell viability, acetylated Histone H3 and H4 levels, cytotoxicity, and cleaved caspase 3 levels, and cell cycle distribution were measured. The viability of BxPC-3 cells decreased significantly after treatment with EF, MS and SAL treatments. MS and SAL treatment increased the acetylation of histone H3 and H4 in a dose dependent manner. MS and SAL alone or combined with EF were increased the number of cells in G1 phase. In addition, treatment with agents significantly decreased the ratio of cell in G2/M phase. There were significant dose-dependent increases at cleaved Caspase 3 levels after MS treatment but not after SAL treatment. Our results showed that HDAC inhibitors (MS and SAL), when combined with EF, may effectively reduce pancreatic cancer cell (BxPC-3) progression and stop the cell cycle at G1 phase. Further molecular analyses are needed to understand the fundamental molecular consequences of HDAC inhibition in pancreas cancer cells.

HDAC6 interacts with PTPN1 to enhance melanoma cells progression.

PubMed

Liu, Jiaqi; Luan, Wenjie; Zhang, Yong; Gu, Jianying; Shi, Yuedong; Yang, Yanwen; Feng, Zihao; Qi, Fazhi

2018-01-22

Histone deacetylase 6 (HDAC6) plays an important role in oncogenic transformation and cancer metastasis. Our previous study has demonstrated that HDAC6 was highly expressed in melanoma cells, and contributed to the proliferation and metastasis of melanoma cells. However, the underlying mechanism of HDAC6 in melanoma metastasis and progression remains largely unclear. In this study, we reported that HDAC6 directly interacted with Tyrosine-protein phosphatase non-receptor type 1 (PTPN1) by performing co-immunoprecipitation (Co-IP) combined with liquid chromatography tandem mass spectrometry (LC-MS/MS). HDAC6 increased the protein level of PTPN1 independent of histone modifying activity. In addition, PTPN1 promoted proliferation, colony formation and migration while decreased apoptosis of melanoma cells through activating extracellular signal-regulated kinase 1/2 (ERK1/2). Furthermore, we found that matrix metallopeptidase 9 (MMP9) was increased by HDAC6/PTPN1/ERK1/2 axis, which might serve as a mechanism for melanoma invasion and metastasis. In conclusion, HDAC6 might enhance aggressive melanoma cells progression via interacting with PTPN1, which was independent of its histone modifying activity. Copyright © 2017. Published by Elsevier Inc.

HDAC4 as a potential therapeutic target in neurodegenerative diseases: a summary of recent achievements

PubMed Central

Mielcarek, Michal; Zielonka, Daniel; Carnemolla, Alisia; Marcinkowski, Jerzy T.; Guidez, Fabien

2015-01-01

For the past decade protein acetylation has been shown to be a crucial post-transcriptional modification involved in the regulation of protein functions. Histone acetyltransferases (HATs) mediate acetylation of histones which results in the nucleosomal relaxation associated with gene expression. The reverse reaction, histone deacetylation, is mediated by histone deacetylases (HDACs) leading to chromatin condensation followed by transcriptional repression. HDACs are divided into distinct classes: I, IIa, IIb, III, and IV, on the basis of size and sequence homology, as well as formation of distinct repressor complexes. Implications of HDACs in many diseases, such as cancer, heart failure, and neurodegeneration, have identified these molecules as unique and attractive therapeutic targets. The emergence of HDAC4 among the members of class IIa family as a major player in synaptic plasticity raises important questions about its functions in the brain. The characterization of HDAC4 specific substrates and molecular partners in the brain will not only provide a better understanding of HDAC4 biological functions but also might help to develop new therapeutic strategies to target numerous malignancies. In this review we highlight and summarize recent achievements in understanding the biological role of HDAC4 in neurodegenerative processes. PMID:25759639

4-Hydroxybenzoic acid derivatives as HDAC6-specific inhibitors modulating microtubular structure and HSP90α chaperone activity against prostate cancer.

PubMed

Seidel, Carole; Schnekenburger, Michael; Mazumder, Aloran; Teiten, Marie-Hélène; Kirsch, Gilbert; Dicato, Mario; Diederich, Marc

2016-01-01

Histone deacetylase (HDAC)6 is a unique isoenzyme targeting specific substrates including α-tubulin and heat shock protein (HSP)90. HDAC6 is involved in protein trafficking and degradation, cell shape and migration. Deregulation of HDAC6 activity is associated with a variety of diseases including cancer leading to a growing interest for developing HDAC6 inhibitors. Here, we identified two new structurally related 4-hydroxybenzoic acids as selective HDAC6 inhibitors reducing proliferation, colony and spheroid formation as well as viability of prostate cancer cells. Both compounds strongly enhanced α-tubulin acetylation leading to remodeling of microtubular organization. Furthermore, 4-hydroxybenzoic acids decreased HSP90α regulation of the human androgen receptor in prostate cancer cells by increasing HSP90α acetylation levels. Collectively, our data support the potential of 4-hydroxybenzoic acid derivatives as HDAC6-specific inhibitors with anti-cancer properties. Copyright © 2015 Elsevier Inc. All rights reserved.

Homology modeling of parasite histone deacetylases to guide the structure-based design of selective inhibitors.

PubMed

Melesina, Jelena; Robaa, Dina; Pierce, Raymond J; Romier, Christophe; Sippl, Wolfgang

2015-11-01

Histone deacetylases (HDACs) are promising epigenetic targets for the treatment of various diseases, including cancer and neurodegenerative disorders. There is evidence that they can also be addressed to treat parasitic infections. Recently, the first X-ray structure of a parasite HDAC was published, Schistosoma mansoni HDAC8, giving structural insights into its inhibition. However, most of the targets from parasites of interest still lack this structural information. Therefore, we prepared homology models of relevant parasitic HDACs and compared them to human and S. mansoni HDACs. The information about known S. mansoni HDAC8 inhibitors and compounds that affect the growth of Trypanosoma, Leishmania and Plasmodium species was used to validate the models by docking and molecular dynamics studies. Our results provide analysis of structural features of parasitic HDACs and should be helpful for selecting promising candidates for biological testing and for structure-based optimisation of parasite-specific inhibitors. Copyright © 2015 Elsevier Inc. All rights reserved.

HDAC inhibition inhibits brachial plexus avulsion induced neuropathic pain.

PubMed

Zhao, Yingbo; Wu, Tianjian

2018-05-09

Introduction Neuropathic pain induced by brachial plexus avulsion (BPA) is a pathological condition. We hypothesized that inhibition of histone deacetylase (HDAC) could suppress BPA-induced neuropathic pain through inhibition of transient reception potential (TRP) overexpression and protein kinase B (Akt) mediated mammalian target of rapamycin (mTOR) activation. Methods We generated a rat BPA model, administered HDAC inhibitor Tricostatin A (TSA) for 7 days post-surgery and assessed the effects on HDAC expression, Akt phosphorylation, neuroinflammation and mTOR activation. Results TSA treatment alleviated BPA induced mechanical hyperalgesia, suppressed Akt phosphorylation and increased HDAC. We found suppressed pro-inflammatory cytokine levels, TRP cation channel subfamily V member 1 (TRPV1) and TRP melastatin 8 (TRPM8) expression and mTOR activity in TSA treated BPA rats. Discussion Our results suggest that altered HDAC and Akt signaling are involved in BPA-induced neuropathic pain and that inhibition of HDAC could be an effective therapeutic approach in reducing neuropathic pain. This article is protected by copyright. All rights reserved. © 2018 Wiley Periodicals, Inc.

HDAC1 links early life stress to schizophrenia-like phenotypes

PubMed Central

Bahari-Javan, Sanaz; Varbanov, Hristo; Halder, Rashi; Benito, Eva; Kaurani, Lalit; Burkhardt, Susanne; Anderson-Schmidt, Heike; Anghelescu, Ion; Budde, Monika; Stilling, Roman M.; Costa, Joan; Medina, Juan; Figge, Christian; Folkerts, Here; Gade, Katrin; Heilbronner, Urs; Koller, Manfred; Konrad, Carsten; Nussbeck, Sara Y.; Scherk, Harald; Spitzer, Carsten; Stierl, Sebastian; Stöckel, Judith; Thiel, Andreas; von Hagen, Martin; Zimmermann, Jörg; Zitzelsberger, Antje; Schulz, Sybille; Schmitt, Andrea; Delalle, Ivana; Falkai, Peter; Schulze, Thomas G.; Dityatev, Alexander; Sananbenesi, Farahnaz; Fischer, André

2017-01-01

Schizophrenia is a devastating disease that arises on the background of genetic predisposition and environmental risk factors, such as early life stress (ELS). In this study, we show that ELS-induced schizophrenia-like phenotypes in mice correlate with a widespread increase of histone-deacetylase 1 (Hdac1) expression that is linked to altered DNA methylation. Hdac1 overexpression in neurons of the medial prefrontal cortex, but not in the dorsal or ventral hippocampus, mimics schizophrenia-like phenotypes induced by ELS. Systemic administration of an HDAC inhibitor rescues the detrimental effects of ELS when applied after the manifestation of disease phenotypes. In addition to the hippocampus and prefrontal cortex, mice subjected to ELS exhibit increased Hdac1 expression in blood. Moreover, Hdac1 levels are increased in blood samples from patients with schizophrenia who had encountered ELS, compared with patients without ELS experience. Our data suggest that HDAC1 inhibition should be considered as a therapeutic approach to treat schizophrenia. PMID:28533418

HDAC6 regulates thermogenesis of brown adipocytes through activating PKA to induce UCP1 expression.

PubMed

Jung, Suna; Han, Miae; Korm, Sovannarith; Lee, Se-In; Noh, Solhee; Phorl, Sophors; Naskar, Rema; Lee, Kye-Sung; Kim, Geon-Hee; Choi, Yun-Jaie; Lee, Joo Yong

2018-06-08

Mitochondrial uncoupling protein 1 (UCP1) is responsible for nonshivering thermogenesis in brown adipose tissue (BAT). UCP1 increases the conductance of the inner mitochondrial membrane (IMM) for protons to make BAT mitochondria generate heat rather than ATP. HDAC6 is a cytosolic deacetylase for non-histone substrates to regulate various cellular processes, including mitochondrial quality control and dynamics. Here, we showed that the body temperature of HDAC6 knockout mice is slightly decreased in normal hosing condition. Interestingly, UCP1 was downregulated in BAT of HDAC6 knockout mice, which extensively linked mitochondrial thermogenesis. Mechanistically, we showed that cAMP-PKA signaling plays a key role in HDAC6-dependent UCP1 expression. Notably, the size of brown adipocytes and lipid droplets in HDAC6 knockout BAT is increased. Taken together, our findings suggested that HDAC6 contributes to mitochondrial thermogenesis in BAT by increasing UCP1 expression through cAMP-PKA signaling pathway. Copyright © 2018. Published by Elsevier Inc.

Enhancing the Sensitivity of Pharmacophore-Based Virtual Screening by Incorporating Customized ZBG Features: A Case Study Using Histone Deacetylase 8.

PubMed

Hou, Xuben; Du, Jintong; Liu, Renshuai; Zhou, Yi; Li, Minyong; Xu, Wenfang; Fang, Hao

2015-04-27

As key regulators of epigenetic regulation, human histone deacetylases (HDACs) have been identified as drug targets for the treatment of several cancers. The proper recognition of zinc-binding groups (ZBGs) will help improve the accuracy of virtual screening for novel HDAC inhibitors. Here, we developed a high-specificity ZBG-based pharmacophore model for HDAC8 inhibitors by incorporating customized ZBG features. Subsequently, pharmacophore-based virtual screening led to the discovery of three novel HDAC8 inhibitors with low micromole IC50 values (1.8-1.9 μM). Further studies demonstrated that compound H8-A5 was selective for HDAC8 over HDAC 1/4 and showed antiproliferation activity in MDA-MB-231 cancer cells. Molecular docking and molecular dynamic studies suggested a possible binding mode for H8-A5, which provides a good starting point for the development of HDAC8 inhibitors in cancer treatment.

Functional differences in epigenetic modulators-superiority of mercaptoacetamide-based histone deacetylase inhibitors relative to hydroxamates in cortical neuron neuroprotection studies.

PubMed

Kozikowski, Alan P; Chen, Yufeng; Gaysin, Arsen; Chen, Bin; D'Annibale, Melissa A; Suto, Carla M; Langley, Brett C

2007-06-28

We compare the ability of two structurally different classes of epigenetic modulators, namely, histone deacetylase (HDAC) inhibitors containing either a hydroxamate or a mercaptoacetamide as the zinc binding group, to protect cortical neurons in culture from oxidative stress-induced death. This study reveals that some of the mercaptoacetamide-based HDAC inhibitors are fully protective, whereas the hydroxamates show toxicity at higher concentrations. Our present results appear to be consistent with the possibility that the mercaptoacetamide-based HDAC inhibitors interact with a different subset of the HDAC isozymes [less activity at HDAC1 and 2 correlates with less inhibitor toxicity], or alternatively, are interacting selectively with only the cytoplasmic HDACs that are crucial for protection from oxidative stress.

HDAC inhibitors TSA and sodium butyrate enhanced the human IL-5 expression by altering histone acetylation status at its promoter region.

PubMed

Han, Songyan; Lu, Jun; Zhang, Yu; Cheng, Cao; Li, Lin; Han, Liping; Huang, Baiqu

2007-02-15

The expression of IL-5 correlated tightly with the maturation and differentiation of eosinophils, and is considered as a cytokine responsible for allergic inflammation. We report here that inhibition of HDAC activity by Trichostatin A (TSA) and sodium butyrate (NaBu), the two specific HDAC inhibitors, resulted in the elevation of both endogenous and exogenous activity of IL-5 promoter. We demonstrated that both the mRNA expression and protein production of IL-5 were stimulated by TSA and NaBu treatments. ChIP assays showed that treatments of TSA and NaBu caused hyperacetylation of histones H3 and H4 on IL-5 promoter in Jurkat cells, which consequently promoted the exogenous luciferase activity driven by this promoter. Moreover, site-directed mutagenesis studies showed that the binding sites for transcription factors NFAT, GATA3 and YY1 on IL-5 promoter were critical for the effects of TSA and NaBu, suggesting that the transcriptional activation of IL-5 gene by these inhibitors was achieved by affecting HDAC function on IL-5 promoter via transcription factors. These data will contribute to elucidating the unique mechanism of IL-5 transcriptional control and to the therapy of allergic disorders related to IL-5.

Isolation and characterization of an osmotic stress and ABA induced histone deacetylase in Arachis hygogaea

PubMed Central

Su, Liang-Chen; Deng, Bin; Liu, Shuai; Li, Li-Mei; Hu, Bo; Zhong, Yu-Ting; Li, Ling

2015-01-01

Histone acetylation, which together with histone methylation regulates gene activity in response to stress, is an important epigenetic modification. There is an increasing research focus on histone acetylation in crops, but there is no information to date in peanut (Arachis hypogaea). We showed that osmotic stress and ABA affect the acetylation of histone H3 loci in peanut seedlings by immunoblotting experiments. Using RNA-seq data for peanut, we found a RPD3/HDA1-like superfamily histone deacetylase (HDAC), termed AhHDA1, whose gene is up-regulated by PEG-induced water limitation and ABA signaling. We isolated and characterized AhHDA1 from A. hypogaea, showing that AhHDA1 is very similar to an Arabidopsis HDAC (AtHDA6) and, in recombinant form, possesses HDAC activity. To understand whether and how osmotic stress and ABA mediate the peanut stress response by epigenetics, the expression of AhHDA1 and stress-responsive genes following treatment with PEG, ABA, and the specific HDAC inhibitor trichostatin A (TSA) were analyzed. AhHDA1 transcript levels were enhanced by all three treatments, as was expression of peanut transcription factor genes, indicating that AhHDA1 might be involved in the epigenetic regulation of stress resistance genes that comprise the responses to osmotic stress and ABA. PMID:26217363

Leukemia/lymphoma-related factor, a POZ domain-containing transcriptional repressor, interacts with histone deacetylase-1 and inhibits cartilage oligomeric matrix protein gene expression and chondrogenesis.

PubMed

Liu, Chuan-ju; Prazak, Lisa; Fajardo, Marc; Yu, Shuang; Tyagi, Neetu; Di Cesare, Paul E

2004-11-05

Mutations in the human cartilage oligomeric matrix protein (COMP) gene have been linked to the development of pseudoachondroplasia and multiple epiphyseal dysplasia. We previously cloned the promoter region of the COMP gene and delineated a minimal negative regulatory element (NRE) that is both necessary and sufficient to repress its promoter (Issack, P. S., Fang, C. H., Leslie, M. P., and Di Cesare, P. E. (2000) J. Orthop. Res. 18, 345-350; Issack, P. S., Liu, C. J., Prazak, L., and Di Cesare, P. E. (2004) J. Orthop. Res. 22, 751-758). In this study, a yeast one-hybrid screen for proteins that associate with the NRE led to the identification of the leukemia/lymphoma-related factor (LRF), a transcriptional repressor that contains a POZ (poxvirus zinc finger) domain, as an NRE-binding protein. LRF bound directly to the NRE both in vitro and in living cells. Nine nucleotides (GAGGGTCCC) in the 30-bp NRE are essential for binding to LRF. LRF showed dose-dependent inhibition of COMP-specific reporter gene activity, and exogenous overexpression of LRF repressed COMP gene expression in both rat chondrosarcoma cells and bone morphogenetic protein-2-treated C3H10T1/2 progenitor cells. In addition, LRF also inhibited bone morphogenetic protein-2-induced chondrogenesis in high density micromass cultures of C3H10T1/2 cells, as evidenced by lack of expression of other chondrocytic markers, such as aggrecan and collagen types II, IX, X, and XI, and by Alcian blue staining. LRF associated with histone deacetylase-1 (HDAC1), and experiments utilizing the HDAC inhibitor trichostatin A revealed that LRF-mediated repression requires deacetylase activity. LRF is the first transcription factor found to bind directly to the COMP gene promoter, to recruit HDAC1, and to regulate both COMP gene expression and chondrogenic differentiation.

Genetic and Chemical Screenings Identify HDAC3 as a Key Regulator in Hepatic Differentiation of Human Pluripotent Stem Cells.

PubMed

Li, Shuang; Li, Mushan; Liu, Xiaojian; Yang, Yuanyuan; Wei, Yuda; Chen, Yanhao; Qiu, Yan; Zhou, Tingting; Feng, Zhuanghui; Ma, Danjun; Fang, Jing; Ying, Hao; Wang, Hui; Musunuru, Kiran; Shao, Zhen; Zhao, Yongxu; Ding, Qiurong

2018-05-24

Hepatocyte-like cells (HLCs) derived from human pluripotent stem cells (hPSCs) offer a promising cell resource for disease modeling and transplantation. However, differentiated HLCs exhibit an immature phenotype and comprise a heterogeneous population. Thus, a better understanding of HLC differentiation will improve the likelihood of future application. Here, by taking advantage of CRISPR-Cas9-based genome-wide screening technology and a high-throughput hPSC screening platform with a reporter readout, we identified several potential genetic regulators of HLC differentiation. By using a chemical screening approach within our platform, we also identified compounds that can further promote HLC differentiation and preserve the characteristics of in vitro cultured primary hepatocytes. Remarkably, both screenings identified histone deacetylase 3 (HDAC3) as a key regulator in hepatic differentiation. Mechanistically, HDAC3 formed a complex with liver transcriptional factors, e.g., HNF4, and co-regulated the transcriptional program during hepatic differentiation. This study highlights a broadly useful approach for studying and optimizing hPSC differentiation. Copyright © 2018 The Author(s). Published by Elsevier Inc. All rights reserved.

Histone deacetylase 5 modulates the effects of social adversity in early life on cocaine-induced behavior.

PubMed

Valzania, Alessandro; Catale, Clarissa; Viscomi, Maria Teresa; Puglisi-Allegra, Stefano; Carola, Valeria

2017-03-15

Psychostimulants induce stable changes in neural plasticity and behavior in a transcription-dependent manner. Further, stable cellular changes require transcription that is regulated by epigenetic mechanisms that alter chromatin structure, such as histone acetylation. This mechanism is typically catalyzed by enzymes with histone acetyltransferase or histone deacetylase (HDAC) activity. Class IIa HDACs are notable for their high expression in important regions of the brain reward circuitry and their neural activity-dependent shuttling in and out of the cell nucleus. In particular, HDAC5 has an important modulatory function in cocaine-induced behaviors and social defeat stress-induced effects. Although a mutation in HDAC5 has been shown to cause hypersensitive responses to chronic cocaine use whether this response worsens during chronic early life stress has not been examined yet. In this study, we exposed mouse pups to two different early life stress paradigms (social isolation, ESI, and social threat, EST) to determine whether the heterozygous null mutation in HDAC5 (HDAC5+/-) moderated the effects of exposure to stress in early life on adult cocaine-induced conditioned place preference (CPP). Notably, HDAC5+/- mice that had been exposed to ESI were more susceptible to developing cocaine-induced CPP and more resistant to extinguishing this behavior. The same effect was not observed for HDAC5+/- mice experiencing EST, suggesting that only ESI induces behavioral changes by acting precisely through HDAC5-related biological pathways. Finally, an analysis of c-Fos expression performed to discover the neurobiological substrates that mediated this phenotype, identified the dorsolateral striatum as an important structure that mediates the interaction between HDAC5 mutation and ESI. Our data demonstrate that decreased HDAC5 function is able to exacerbate the long-term behavioral effects of adverse rearing environment in mouse. Copyright © 2016 Elsevier Inc. All rights reserved.

HDAC2 Suppresses IL17A-Mediated Airway Remodeling in Human and Experimental Modeling of COPD.

PubMed

Lai, Tianwen; Tian, Baoping; Cao, Chao; Hu, Yue; Zhou, Jiesen; Wang, Yong; Wu, Yanping; Li, Zhouyang; Xu, Xuchen; Zhang, Min; Xu, Feng; Cao, Yuan; Chen, Min; Wu, Dong; Wu, Bin; Dong, Chen; Li, Wen; Ying, Songmin; Chen, Zhihua; Shen, Huahao

2018-04-01

Although airway remodeling is a central feature of COPD, the mechanisms underlying its development have not been fully elucidated. The goal of this study was to determine whether histone deacetylase (HDAC) 2 protects against cigarette smoke (CS)-induced airway remodeling through IL-17A-dependent mechanisms. Sputum samples and lung tissue specimens were obtained from control subjects and patients with COPD. The relationships between HDAC2, IL-17A, and airway remodeling were investigated. The effect of HDAC2 on IL-17A-mediated airway remodeling was assessed by using in vivo models of COPD induced by CS and in vitro culture of human bronchial epithelial cells and primary human fibroblasts exposed to CS extract, IL-17A, or both. HDAC2 and IL-17A expression in the sputum cells and lung tissue samples of patients with COPD were associated with bronchial wall thickening and collagen deposition. Il-17a deficiency (Il-17a -/- ) resulted in attenuation of, whereas Hdac2 deficiency (Hdac2 +/- ) exacerbated, CS-induced airway remodeling in mice. IL-17A deletion also attenuated airway remodeling in CS-exposed Hdac2 +/- mice. HDAC2 regulated IL-17A production partially through modulation of CD4 + T cells during T helper 17 cell differentiation and retinoid-related orphan nuclear receptor γt in airway epithelial cells. In vitro, IL-17A deficiency attenuated CS-induced mouse fibroblast activation from Hdac2 +/- mice. IL-17A-induced primary human fibroblast activation was at least partially mediated by autocrine production of transforming growth factor beta 1. These findings suggest that activation of HDAC2 and/or inhibition of IL-17A production could prevent the development of airway remodeling by suppressing airway inflammation and modulating fibroblast activation in COPD. Copyright © 2017. Published by Elsevier Inc.

Hippocampal HDAC4 contributes to postnatal fluoxetine-evoked depression-like behavior.

PubMed

Sarkar, Ambalika; Chachra, Parul; Kennedy, Pamela; Pena, Catherine J; Desouza, Lynette A; Nestler, Eric J; Vaidya, Vidita A

2014-08-01

Fluoxetine treatment in adulthood evokes antidepressant and anxiolytic responses. Paradoxically, postnatal fluoxetine (PNFlx) induces persistent depression- and anxiety-like behaviors. The mechanistic underpinnings of this paradox remain poorly understood. Here, we examined specific molecular changes in the rat hippocampus that accompany perturbed emotionality observed across life following PNFlx. PNFlx-induced hippocampal gene regulation observed in microarray and quantitative PCR studies indicate functional enrichment of genes involved in response to organic substances, protein kinase pathways, DNA binding, and transcriptional repression. We noted specific transcripts (Hdac4, mammalian target of rapamycin (mTOR), Gnai1, protein kinase C gamma (Prkcc), and hyperpolarization-activated cyclic nucleotide-gated channel 1 (Hcn1)) that were consistently dysregulated across life, and selectively influenced by postnatal, but not adult, fluoxetine. Increased histone deacetylase-4 (HDAC4) recruitment, accompanied by decreased activating histone acetylation marks at the mTOR and Gnai1 promoters, indicate a role for HDAC4 in PNFlx-mediated gene dysregulation. Strikingly, coadministration of the HDAC inhibitor sodium butyrate with PNFlx prevented the dysregulation of Hdac4 and mTOR, and the emergence of depression- and anxiety-like behavior. Importantly, we also find that retreatment of PNFlx animals with fluoxetine in adulthood reversed the increased Hdac4 expression, prevented HDAC4 recruitment to the mTOR and Gnai1 promoters, and attenuated the decline in mTOR and Gnai1 expression, coincident with normalization of PNFlx-evoked depression- and anxiety-like behavior. Further, we show that viral-mediated hippocampal overexpression of Hdac4 was sufficient to induce depression-, but not anxiety-, like behavior in adulthood. Our results highlight the unique nature of molecular signatures evoked by PNFlx, and implicate HDAC4 in the dysregulated gene expression and emergence of perturbed emotionality following fluoxetine exposure in early life.

Cdyl: a new transcriptional co-repressor

PubMed Central

Caron, Cécile; Pivot-Pajot, Christophe; van Grunsven, Leo A.; Col, Edwige; Lestrat, Cécile; Rousseaux, Sophie; Khochbin, Saadi

2003-01-01

Cdyl (chromodomain-Y-like) is a chromodomain-containing protein that is predominantly expressed during mouse spermiogenesis. In its carboxy-terminal portion, there is a domain with homology to the coenzyme A (CoA) pocket of the enoyl-CoA hydratase/isomerase, which is shown here to be able to bind CoA and histone deacetylases (HDACs). It also efficiently represses transcription. Moreover, the binding of Hdac1 represses the ability of Cdyl to bind CoA, and a Cdyl–CoA interaction only occurs in the absence of HDACs. These data suggest that Cdyl is primarily a transcriptional co-repressor. However, the degradation of cellular Hdac1 and Hdac2, as observed here in the elongating spermatids, may provide an HDAC-free environment in which Cdyl could bind CoA and participate in the global chromatin remodelling that occurs in these cells. PMID:12947414

Promiscuous Actions of Small Molecule Inhibitors of the Protein Kinase D-Class IIa HDAC Axis in Striated Muscle

PubMed Central

Lemon, Douglas D.; Harrison, Brooke C.; Horn, Todd R.; Stratton, Matthew S.; Ferguson, Bradley S.; Wempe, Michael F.; McKinsey, Timothy A.

2015-01-01

PKD-mediated phosphorylation of class IIa HDACs frees the MEF2 transcription factor to activate genes that govern muscle differentiation and growth. Studies of the regulation and function of this signaling axis have involved MC1568 and Gö-6976, which are small molecule inhibitors of class IIa HDAC and PKD catalytic activity, respectively. We describe unanticipated effects of these compounds. MC1568 failed to inhibit class IIa HDAC catalytic activity in vitro, and exerted divergent effects on skeletal muscle differentiation compared to a bona fide inhibitor of these HDACs. In cardiomyocytes, Gö-6976 triggered calcium signaling and activated stress-inducible kinases. Based on these findings, caution is warranted when employing MC1568 and Gö-6976 as pharmacological tool compounds to assess functions of class IIa HDACs and PKD. PMID:25816750

Tetraspanin CD9 modulates human lymphoma cellular proliferation via histone deacetylase activity

DOE Office of Scientific and Technical Information (OSTI.GOV)

Herr, Michael J.; Department of Medicine, The University of Tennessee Health Science Center, Memphis, TN 38163; Department of Molecular Sciences, The University of Tennessee Health Science Center, Memphis, TN 38163

2014-05-16

Highlights: • CD9 is differentially expressed in human Burkitt’s lymphoma cells. • We found that CD9 expression promotes these cells proliferation. • CD9 expression also increases HDAC activity. • HDAC inhibition decreased both cell proliferation and importantly CD9 expression. • CD9 may dictate HDAC efficacy and play a role in HDAC regulation. - Abstract: Non-Hodgkin Lymphoma (NHL) is a type of hematological malignancy that affects two percent of the overall population in the United States. Tetraspanin CD9 is a cell surface protein that has been thoroughly demonstrated to be a molecular facilitator of cellular phenotype. CD9 expression varies in twomore » human lymphoma cell lines, Raji and BJAB. In this report, we investigated the functional relationship between CD9 and cell proliferation regulated by histone deacetylase (HDAC) activity in these two cell lines. Introduction of CD9 expression in Raji cells resulted in significantly increased cell proliferation and HDAC activity compared to Mock transfected Raji cells. The increase in CD9–Raji cell proliferation was significantly inhibited by HDAC inhibitor (HDACi) treatment. Pretreatment of BJAB cells with HDAC inhibitors resulted in a significant decrease in endogenous CD9 mRNA and cell surface expression. BJAB cells also displayed decreased cell proliferation after HDACi treatment. These results suggest a significant relationship between CD9 expression and cell proliferation in human lymphoma cells that may be modulated by HDAC activity.« less

The multi zinc-finger protein Trps1 acts as a regulator of histone deacetylation during mitosis.

PubMed

Wuelling, Manuela; Pasdziernik, Markus; Moll, Carina N; Thiesen, Andrea M; Schneider, Sabine; Johannes, Christian; Vortkamp, Andrea

2013-07-15

TRPS1, the gene mutated in human "Tricho-Rhino-Phalangeal syndrome," encodes a multi zinc-finger nuclear regulator of chondrocyte proliferation and differentiation. Here, we have identified a new function of Trps1 in controlling mitotic progression in chondrocytes. Loss of Trps1 in mice leads to an increased proportion of cells arrested in mitosis and, subsequently, to chromosome segregation defects. Searching for the molecular basis of the defect, we found that Trps1 acts as regulator of histone deacetylation. Trps1 interacts with two histone deacetylases, Hdac1 and Hdac4, thereby increasing their activity. Loss of Trps1 results in histone H3 hyperacetylation, which is maintained during mitosis. Consequently, chromatin condensation and binding of HP1 is impaired, and Trps1-deficient chondrocytes accumulate in prometaphase. Overexpression of Hdac4 rescues the mitotic defect of Trps1-deficient chondrocytes, identifying Trps1 as an important regulator of chromatin deacetylation during mitosis in chondrocytes. Our data provide the first evidence that the control of mitosis can be linked to the regulation of chondrocyte differentiation by epigenetic consequences of altered Hdac activity.

Tonic LAT-HDAC7 Signals Sustain Nur77 and Irf4 Expression to Tune Naive CD4 T Cells.

PubMed

Myers, Darienne R; Lau, Tannia; Markegard, Evan; Lim, Hyung W; Kasler, Herbert; Zhu, Minghua; Barczak, Andrea; Huizar, John P; Zikherman, Julie; Erle, David J; Zhang, Weiguo; Verdin, Eric; Roose, Jeroen P

2017-05-23

CD4 + T cells differentiate into T helper cell subsets in feedforward manners with synergistic signals from the T cell receptor (TCR), cytokines, and lineage-specific transcription factors. Naive CD4 + T cells avoid spontaneous engagement of feedforward mechanisms but retain a prepared state. T cells lacking the adaptor molecule LAT demonstrate impaired TCR-induced signals yet cause a spontaneous lymphoproliferative T helper 2 (T H 2) cell syndrome in mice. Thus, LAT constitutes an unexplained maintenance cue. Here, we demonstrate that tonic signals through LAT constitutively export the repressor HDAC7 from the nucleus of CD4 + T cells. Without such tonic signals, HDAC7 target genes Nur77 and Irf4 are repressed. We reveal that Nur77 suppresses CD4 + T cell proliferation and uncover a suppressive role for Irf4 in T H 2 polarization; halving Irf4 gene-dosage leads to increases in GATA3 + and IL-4 + cells. Our studies reveal that naive CD4 + T cells are dynamically tuned by tonic LAT-HDAC7 signals. Published by Elsevier Inc.

Synchrotron x-ray spectroscopy of EuHN O3 aqueous solutions at high temperatures and pressures and Nb-bearing silicate melt phases coexisting with hydrothermal fluids using a modified hydrothermal diamond anvil cell and rail assembly

USGS Publications Warehouse

Mayanovic, Robert A.; Anderson, Alan J.; Bassett, William A.; Chou, I.-Ming

2007-01-01

A modified hydrothermal diamond anvil cell (HDAC) rail assembly has been constructed for making synchrotron x-ray absorption spectroscopy, x-ray fluorescence, and x-ray mapping measurements on fluids or solid phases in contact with hydrothermal fluids up to ???900??C and 700 MPa. The diamond anvils of the HDAC are modified by laser milling grooves or holes, for the reduction of attenuation of incident and fluorescent x rays and sample cavities. The modified HDAC rail assembly has flexibility in design for measurement of light elements at low concentrations or heavy elements at trace levels in the sample and the capability to probe minute individual phases of a multiphase fluid-based system using focused x-ray microbeam. The supporting rail allows for uniform translation of the HDAC, rotation and tilt stages, and a focusing mirror, which is used to illuminate the sample for visual observation using a microscope, relative to the direction of the incident x-ray beam. A structure study of Eu(III) aqua ion behavior in high-temperature aqueous solutions and a study of Nb partitioning and coordination in a silicate melt in contact with a hydrothermal fluid are described as applications utilizing the modified HDAC rail assembly. ?? 2007 American Institute of Physics.

Histone Deacetylase Adaptation in Single Ventricle Heart Disease and a Young Animal Model of Right Ventricular Hypertrophy

PubMed Central

Blakeslee, Weston W.; Demos-Davies, Kimberly M.; Lemon, Douglas D.; Lutter, Katharina M.; Cavasin, Maria A.; Payne, Sam; Nunley, Karin; Long, Carlin S.; McKinsey, Timothy A.; Miyamoto, Shelley D.

2017-01-01

Background Histone deacetylase (HDAC) inhibitors are promising therapeutics for various forms of cardiac disease. The purpose of this study was to assess cardiac HDAC catalytic activity and expression in children with single ventricle heart disease of right ventricular morphology (SV), as well as in a rodent model of right ventricular hypertrophy (RVH). Methods Homogenates of RV explants from non-failing controls and SV children were assayed for HDAC catalytic activity and HDAC isoform expression. Postnatal 1-day old rat pups were placed in hypoxic conditions and echocardiographic analysis, gene expression, HDAC catalytic activity and isoform expression studies of the RV were performed. Results Class I, IIa, and IIb HDAC catalytic activity and protein expression were elevated in hearts of SV children. Hypoxic neonatal rats demonstrated RVH, abnormal gene expression and elevated class I and class IIb HDAC catalytic activity and protein expression in the RV compared to control. Conclusions These data suggest that myocardial HDAC adaptations occur in the SV heart and could represent a novel therapeutic target. While further characterization of the hypoxic neonatal rat is needed, this animal model may be suitable for pre-clinical investigations of pediatric RV disease and could serve as a useful model for future mechanistic studies. PMID:28549058

Class I HDACs Regulate Angiotensin II-Dependent Cardiac Fibrosis via Fibroblasts and Circulating Fibrocytes

PubMed Central

Williams, Sarah M.; Golden-Mason, Lucy; Ferguson, Bradley S.; Douglas, Katherine B.; Cavasin, Maria A.; Demos-Davies, Kim; Yeager, Michael E.; Stenmark, Kurt R.; McKinsey, Timothy A.

2014-01-01

Fibrosis, which is defined as excessive accumulation of fibrous connective tissue, contributes to the pathogenesis of numerous diseases involving diverse organ systems. Cardiac fibrosis predisposes individuals to myocardial ischemia, arrhythmias and sudden death, and is commonly associated with diastolic dysfunction. Histone deacetylase (HDAC) inhibitors block cardiac fibrosis in pre-clinical models of heart failure. However, which HDAC isoforms govern cardiac fibrosis, and the mechanisms by which they do so, remains unclear. Here, we show that selective inhibition of class I HDACs potently suppresses angiotensin II (Ang II)-mediated cardiac fibrosis by targeting two key effector cell populations, cardiac fibroblasts and bone marrow-derived fibrocytes. Class I HDAC inhibition blocks cardiac fibroblast cell cycle progression through derepression of the genes encoding the cyclin-dependent kinase (CDK) inhibitors, p15 and p57. In contrast, class I HDAC inhibitors block agonist-dependent differentiation of fibrocytes through a mechanism involving repression of ERK1/2 signaling. These findings define novel roles for class I HDACs in the control of pathological cardiac fibrosis. Furthermore, since fibrocytes have been implicated in the pathogenesis of a variety of human diseases, including heart, lung and kidney failure, our results suggest broad utility for isoform-selective HDAC inhibitors as anti-fibrotic agents that function, in part, by targeting these circulating mesenchymal cells. PMID:24374140

Structural studies of human histone deacetylase 8 and its site-specific variants complexed with substrate and inhibitors.

PubMed

Dowling, Daniel P; Gantt, Stephanie L; Gattis, Samuel G; Fierke, Carol A; Christianson, David W

2008-12-23

Metal-dependent histone deacetylases (HDACs) require Zn(2+) or Fe(2+) to regulate the acetylation of lysine residues in histones and other proteins in eukaryotic cells. Isozyme HDAC8 is perhaps the archetypical member of the class I HDAC family and serves as a paradigm for studying structure-function relationships. Here, we report the structures of HDAC8 complexes with trichostatin A and 3-(1-methyl-4-phenylacetyl-1H-2-pyrrolyl)-N-hydroxy-2-propenamide (APHA) in a new crystal form. The structure of the APHA complex reveals that the hydroxamate CO group accepts a hydrogen bond from Y306 but does not coordinate to Zn(2+) with favorable geometry, perhaps due to the constraints of its extended pi system. Additionally, since APHA binds to only two of the three protein molecules in the asymmetric unit of this complex, the structure of the third monomer represents the first structure of HDAC8 in the unliganded state. Comparison of unliganded and liganded structures illustrates ligand-induced conformational changes in the L2 loop that likely accompany substrate binding and catalysis. Furthermore, these structures, along with those of the D101N, D101E, D101A, and D101L variants, support the proposal that D101 is critical for the function of the L2 loop. However, amino acid substitutions for D101 can also trigger conformational changes of Y111 and W141 that perturb the substrate binding site. Finally, the structure of H143A HDAC8 complexed with an intact acetylated tetrapeptide substrate molecule confirms the importance of D101 for substrate binding and reveals how Y306 and the active site zinc ion together bind and activate the scissile amide linkage of acetyllysine.

Zinc binding in HDAC inhibitors: a DFT study.

PubMed

Wang, Difei; Helquist, Paul; Wiest, Olaf

2007-07-06

Histone deacetylases (HDACs) are attractive targets for the treatment of cancers and a variety of other diseases. Most currently studied HDAC inhibitors contain hydroxamic acids, which are potentially problematic in the development of practical drugs. DFT calculations of the binding modes and free energies of binding for a variety of other functionalities in a model active site of HDAC are described. The protonation state of hydroxamic acids in the active site and the origin of the high affinity are discussed. These results emphasize the importance of a carefully chosen pKa for zinc binding and provide guidance for the design of novel, non-hydroxamic acid HDAC inhibitors.

Epigenetic control of skull morphogenesis by histone deacetylase 8

PubMed Central

Haberland, Michael; Mokalled, Mayssa H.; Montgomery, Rusty L.; Olson, Eric N.

2009-01-01

Histone deacetylases (Hdacs) are transcriptional repressors with crucial roles in mammalian development. Here we provide evidence that Hdac8 specifically controls patterning of the skull by repressing a subset of transcription factors in cranial neural crest cells. Global deletion of Hdac8 in mice leads to perinatal lethality due to skull instability, and this is phenocopied by conditional deletion of Hdac8 in cranial neural crest cells. Hdac8 specifically represses the aberrant expression of homeobox transcription factors such as Otx2 and Lhx1. These findings reveal how the identity and patterning of vertebrate-specific portions of the skull are epigenetically controlled by a histone deacetylase. PMID:19605684

Vorinostat, an HDAC inhibitor attenuates epidermoid squamous cell carcinoma growth by dampening mTOR signaling pathway in a human xenograft murine model

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kurundkar, Deepali; Srivastava, Ritesh K.; Chaudhary, Sandeep C.

Histone deacetylase (HDAC) inhibitors are potent anticancer agents and show efficacy against various human neoplasms. Vorinostat is a potent HDAC inhibitor and has shown potential to inhibit growth of human xenograft tumors. However, its effect on the growth of skin neoplasm remains undefined. In this study, we show that vorinostat (2 μM) reduced expression of HDAC1, 2, 3, and 7 in epidermoid carcinoma A431 cells. Consistently, it increased acetylation of histone H3 and p53. Vorinostat (100 mg/kg body weight, IP) treatment reduced human xenograft tumor growth in highly immunosuppressed nu/nu mice. Histologically, the vorinostat-treated tumor showed features of well-differentiation withmore » large necrotic areas. Based on proliferating cell nuclear antigen (PCNA) staining and expression of cyclins D1, D2, E, and A, vorinostat seems to impair proliferation by down-regulating the expression of these proteins. However, it also induced apoptosis. The mechanism by which vorinostat blocks proliferation and makes tumor cells prone to apoptosis, involved inhibition of mTOR signaling which was accompanied by reduction in cell survival AKT and extracellular-signal regulated kinase (ERK) signaling pathways. Our data provide a novel mechanism-based therapeutic intervention for cutaneous squamous cell carcinoma (SCC). Vorinostat may be utilized to cure skin neoplasms in organ transplant recipient (OTR). These patients have high morbidity and surgical removal of these lesions which frequently develop in these patients, is difficult. -- Highlights: ► Vorinostat reduces SCC growth in a xenograft murine model. ► Vorinostat dampens proliferation and induces apoptosis in tumor cells. ► Diminution in mTOR, Akt and ERK signaling underlies inhibition in proliferation. ► Vorinostat by inhibiting HDACs inhibits epithelial–mesenchymal transition.« less

Comprehensive identification of genes driven by ERV9-LTRs reveals TNFRSF10B as a re-activatable mediator of testicular cancer cell death

PubMed Central

Beyer, U; Krönung, S K; Leha, A; Walter, L; Dobbelstein, M

2016-01-01

The long terminal repeat (LTR) of human endogenous retrovirus type 9 (ERV9) acts as a germline-specific promoter that induces the expression of a proapoptotic isoform of the tumor suppressor homologue p63, GTAp63, in male germline cells. Testicular cancer cells silence this promoter, but inhibitors of histone deacetylases (HDACs) restore GTAp63 expression and give rise to apoptosis. We show here that numerous additional transcripts throughout the genome are driven by related ERV9-LTRs. 3' Rapid amplification of cDNA ends (3'RACE) was combined with next-generation sequencing to establish a large set of such mRNAs. HDAC inhibitors induce these ERV9-LTR-driven genes but not the LTRs from other ERVs. In particular, a transcript encoding the death receptor DR5 originates from an ERV9-LTR inserted upstream of the protein coding regions of the TNFRSF10B gene, and it shows an expression pattern similar to GTAp63. When treating testicular cancer cells with HDAC inhibitors as well as the death ligand TNF-related apoptosis-inducing ligand (TRAIL), rapid cell death was observed, which depended on TNFRSF10B expression. HDAC inhibitors also cooperate with cisplatin (cDDP) to promote apoptosis in testicular cancer cells. ERV9-LTRs not only drive a large set of human transcripts, but a subset of them acts in a proapoptotic manner. We propose that this avoids the survival of damaged germ cells. HDAC inhibition represents a strategy of restoring the expression of a class of ERV9-LTR-mediated genes in testicular cancer cells, thereby re-enabling tumor suppression. PMID:26024393

Beta-adrenergic signaling promotes tumor angiogenesis and prostate cancer progression through HDAC2-mediated suppression of thrombospondin-1.

PubMed

Hulsurkar, M; Li, Z; Zhang, Y; Li, X; Zheng, D; Li, W

2017-03-01

Chronic behavioral stress and beta-adrenergic signaling have been shown to promote cancer progression, whose underlying mechanisms are largely unclear, especially the involvement of epigenetic regulation. Histone deacetylase-2 (HDAC2), an epigenetic regulator, is critical for stress-induced cardiac hypertrophy. It is unknown whether it is necessary for beta-adrenergic signaling-promoted cancer progression. Using xenograft models, we showed that chronic behavioral stress and beta-adrenergic signaling promote angiogenesis and prostate cancer progression. HDAC2 was induced by beta-adrenergic signaling in vitro and in mouse xenografts. We next uncovered that HDAC2 is a direct target of cAMP response element-binding protein (CREB) that is activated by beta-adrenergic signaling. Notably, HDAC2 is necessary for beta-adrenergic signaling to induce angiogenesis. We further demonstrated that, upon CREB activation, HDAC2 represses thrombospondin-1 (TSP1), a potent angiogenesis inhibitor, through epigenetic regulation. Together, these data establish a novel pathway that HDAC2 and TSP1 act downstream of CREB activation in beta-adrenergic signaling to promote cancer progression.

Chemical and structural biology of protein lysine deacetylases

PubMed Central

YOSHIDA, Minoru; KUDO, Norio; KOSONO, Saori; ITO, Akihiro

2017-01-01

Histone acetylation is a reversible posttranslational modification that plays a fundamental role in regulating eukaryotic gene expression and chromatin structure/function. Key enzymes for removing acetyl groups from histones are metal (zinc)-dependent and NAD+-dependent histone deacetylases (HDACs). The molecular function of HDACs have been extensively characterized by various approaches including chemical, molecular, and structural biology, which demonstrated that HDACs regulate cell proliferation, differentiation, and metabolic homeostasis, and that their alterations are deeply involved in various human disorders including cancer. Notably, drug discovery efforts have achieved success in developing HDAC-targeting therapeutics for treatment of several cancers. However, recent advancements in proteomics technology have revealed much broader aspects of HDACs beyond gene expression control. Not only histones but also a large number of cellular proteins are subject to acetylation by histone acetyltransferases (HATs) and deacetylation by HDACs. Furthermore, some of their structures can flexibly accept and hydrolyze other acyl groups on protein lysine residues. This review mainly focuses on structural aspects of HDAC enzymatic activity regulated by interaction with substrates, co-factors, small molecule inhibitors, and activators. PMID:28496053

Ketamine produces antidepressant-like effects through phosphorylation-dependent nuclear export of histone deacetylase 5 (HDAC5) in rats

PubMed Central

Choi, Miyeon; Lee, Seung Hoon; Wang, Sung Eun; Ko, Seung Yeon; Song, Mihee; Choi, June-Seek; Duman, Ronald S.; Son, Hyeon

2015-01-01

Ketamine produces rapid antidepressant-like effects in animal assays for depression, although the molecular mechanisms underlying these behavioral actions remain incomplete. Here, we demonstrate that ketamine rapidly stimulates histone deacetylase 5 (HDAC5) phosphorylation and nuclear export in rat hippocampal neurons through calcium/calmodulin kinase II- and protein kinase D-dependent pathways. Consequently, ketamine enhanced the transcriptional activity of myocyte enhancer factor 2 (MEF2), which leads to regulation of MEF2 target genes. Transfection of a HDAC5 phosphorylation-defective mutant (Ser259/Ser498 replaced by Ala259/Ala498, HDAC5-S/A), resulted in resistance to ketamine-induced nuclear export, suppression of ketamine-mediated MEF2 transcriptional activity, and decreased expression of MEF2 target genes. Behaviorally, viral-mediated hippocampal knockdown of HDAC5 blocked or occluded the antidepressant effects of ketamine both in unstressed and stressed animals. Taken together, our results reveal a novel role of HDAC5 in the actions of ketamine and suggest that HDAC5 could be a potential mechanism contributing to the therapeutic actions of ketamine. PMID:26647181

A role for histone deacetylases in the cellular and behavioral mechanisms underlying learning and memory.

PubMed

Mahgoub, Melissa; Monteggia, Lisa M

2014-10-01

Histone deacetylases (HDACs) are a family of chromatin remodeling enzymes that restrict access of transcription factors to the DNA, thereby repressing gene expression. In contrast, histone acetyltransferases (HATs) relax the chromatin structure allowing for an active chromatin state and promoting gene transcription. Accumulating data have demonstrated a crucial function for histone acetylation and histone deacetylation in regulating the cellular and behavioral mechanisms underlying synaptic plasticity and learning and memory. In trying to delineate the roles of individual HDACs, genetic tools have been used to manipulate HDAC expression in rodents, uncovering distinct contributions of individual HDACs in regulating the processes of memory formation. Moreover, recent findings have suggested an important role for HDAC inhibitors in enhancing learning and memory processes as well as ameliorating symptoms related to neurodegenerative diseases. In this review, we focus on the role of HDACs in learning and memory, as well as significant data emerging from the field in support of HDAC inhibitors as potential therapeutic targets for the treatment of cognitive disorders. © 2014 Mahgoub and Monteggia; Published by Cold Spring Harbor Laboratory Press.