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Krasilnikova MM, Humphries CL, Shinsky EM. Friedreich's ataxia: new insights. Emerg Top Life Sci 2023; 7:313-323. [PMID: 37698160 DOI: 10.1042/etls20230017] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/28/2023] [Revised: 08/09/2023] [Accepted: 08/29/2023] [Indexed: 09/13/2023]
Abstract
Friedreich ataxia (FRDA) is an inherited disease that is typically caused by GAA repeat expansion within the first intron of the FXN gene coding for frataxin. This results in the frataxin deficiency that affects mostly muscle, nervous, and cardiovascular systems with progressive worsening of the symptoms over the years. This review summarizes recent progress that was achieved in understanding of molecular mechanism of the disease over the last few years and latest treatment strategies focused on overcoming the frataxin deficiency.
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Affiliation(s)
- Maria M Krasilnikova
- Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, U.S.A
| | - Casey L Humphries
- Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, U.S.A
| | - Emily M Shinsky
- Biochemistry and Molecular Biology, The Pennsylvania State University, University Park, Pennsylvania, U.S.A
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2
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Mukherjee A, Zamani F, Suzuki T. Evolution of Slow-Binding Inhibitors Targeting Histone Deacetylase Isoforms. J Med Chem 2023; 66:11672-11700. [PMID: 37651268 DOI: 10.1021/acs.jmedchem.3c01160] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/02/2023]
Abstract
Because the overexpression of histone deacetylase enzymes (HDACs) has been linked to numerous diseases, including various cancers and neurodegenerative disorders, HDAC inhibitors have emerged as promising therapeutic agents. However, most HDAC inhibitors lack both subclass and isoform selectivity, which leads to potential toxicity. Unlike classical hydroxamate HDAC inhibitors, slow-binding HDAC inhibitors form tight and prolonged bonds with HDAC enzymes. This distinct mechanism of action improves both selectivity and toxicity profiles, which makes slow-binding HDAC inhibitors a promising class of therapeutic agents for various diseases. Therefore, the development of slow-binding HDAC inhibitors that can effectively target a wide range of HDAC isoforms is crucial. This Perspective provides valuable insights into the potential and progress of slow-binding HDAC inhibitors as promising drug candidates for the treatment of various diseases.
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Affiliation(s)
| | - Farzad Zamani
- SANKEN, Osaka University, Mihogaoka, Ibaraki, Osaka 567-0047, Japan
| | - Takayoshi Suzuki
- SANKEN, Osaka University, Mihogaoka, Ibaraki, Osaka 567-0047, Japan
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3
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Alva E, Rubens J, Chi S, Rosenberg T, Reddy A, Raabe EH, Margol A. Recent progress and novel approaches to treating atypical teratoid rhabdoid tumor. Neoplasia 2023; 37:100880. [PMID: 36773516 PMCID: PMC9929860 DOI: 10.1016/j.neo.2023.100880] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2022] [Revised: 01/12/2023] [Accepted: 01/23/2023] [Indexed: 02/11/2023]
Abstract
Atypical teratoid rhabdoid tumors (AT/RT) are malignant central nervous system (CNS) tumors that occur mostly in young children and have historically carried a very poor prognosis. While recent clinical trial results show that this tumor is curable, outcomes are still poor compared to other central nervous system embryonal tumors. We here review prior AT/RT clinical trials and highlight promising pre-clinical results that may inform novel clinical approaches to this aggressive cancer.
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Affiliation(s)
- Elizabeth Alva
- Division of Pediatric Hematology-Oncology, Department of Pediatrics, University of Alabama at Birmingham, Birmingham, Alabama, USA
| | - Jeffrey Rubens
- Division of Pediatric Oncology, Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA
| | - Susan Chi
- Dana-Farber Cancer Institute, Children's Hospital Boston, Boston, MA, USA
| | - Tom Rosenberg
- Dana-Farber Cancer Institute, Children's Hospital Boston, Boston, MA, USA
| | - Alyssa Reddy
- Departments of Neurology and Pediatrics, University of California San Francisco, San Francisco, CA, USA
| | - Eric H Raabe
- Division of Pediatric Oncology, Department of Oncology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Ashley Margol
- Children's Hospital Los Angeles, Los Angeles, CA, USA; Department of Pediatrics, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA.
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4
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Schäker-Hübner L, Haschemi R, Büch T, Kraft FB, Brumme B, Schöler A, Jenke R, Meiler J, Aigner A, Bendas G, Hansen FK. Balancing Histone Deacetylase (HDAC) Inhibition and Drug‐likeness: Biological and Physicochemical Evaluation of Class I Selective HDAC Inhibitors. ChemMedChem 2022; 17:e202100755. [PMID: 35073610 PMCID: PMC9303312 DOI: 10.1002/cmdc.202100755] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2021] [Indexed: 11/08/2022]
Abstract
Herein we report the structure‐activity and structure‐physicochemical property relationships of a series of class I selective ortho‐aminoanilides targeting the “foot‐pocket” in HDAC1&2. To balance the structural benefits and the physicochemical disadvantages of these substances, we started with a set of HDACi related to tacedinaline (CI‐994) and evaluated their solubility, lipophilicity (log D7.4) and inhibition of selected HDAC isoforms. Subsequently, we selected the most promising “capless” HDACi and transferred its ZBG to our previously published scaffold featuring a peptoid‐based cap group. The resulting hit compound 10 c (LSH‐A54) showed favorable physicochemical properties and is a potent, selective HDAC1/2 inhibitor. The following evaluation of its slow binding properties revealed that LSH‐A54 binds tightly to HDAC1 in an induced‐fit mechanism. The potent HDAC1/2 inhibitory properties were reflected by attenuated cell migration in a modified wound healing assay and reduced cell viability in a clonogenic survival assay in selected breast cancer cell lines.
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Affiliation(s)
| | - Reza Haschemi
- Rheinische Friedrich-Wilhelms-Universität Bonn: Rheinische Friedrich-Wilhelms-Universitat Bonn Pharmaceutical and Cell Biological Chemistry GERMANY
| | - Thomas Büch
- Leipzig University: Universitat Leipzig Rudolf-Böhm-Institut GERMANY
| | - Fabian B Kraft
- Rheinische Friedrich-Wilhelms-Universitat Bonn Pharmaceutical and Cell Biological Chemistry GERMANY
| | - Birke Brumme
- Leipzig University: Universitat Leipzig Institute for Drug Discovery GERMANY
| | - Andrea Schöler
- Leipzig University: Universitat Leipzig Institute for Drug Discovery GERMANY
| | - Robert Jenke
- Leipzig University: Universitat Leipzig Rudlof-Böhm-Institut GERMANY
| | - Jens Meiler
- Leipzig University: Universitat Leipzig Institute for Drug Discovery GERMANY
| | - Achim Aigner
- Leipzig University: Universitat Leipzig Rudolf-Böhm-Institut GERMANY
| | - Gerd Bendas
- Rheinische Friedrich-Wilhelms-Universität Bonn: Rheinische Friedrich-Wilhelms-Universitat Bonn Pharmaceutical and Cell Biological Chemistry GERMANY
| | - Finn Kristian Hansen
- Rheinische Friedrich-Wilhelms-Universitat Bonn Pharmaceutical Institute An der Immenburg 4 53121 Bonn GERMANY
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In Silico Analysis to Explore Lineage-Independent and -Dependent Transcriptional Programs Associated with the Process of Endothelial and Neural Differentiation of Human Induced Pluripotent Stem Cells. J Clin Med 2021; 10:jcm10184161. [PMID: 34575270 PMCID: PMC8471316 DOI: 10.3390/jcm10184161] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2021] [Revised: 09/11/2021] [Accepted: 09/13/2021] [Indexed: 11/17/2022] Open
Abstract
Despite a major interest in understanding how the endothelial cell phenotype is established, the underlying molecular basis of this process is not yet fully understood. We have previously reported the generation of induced pluripotent stem cells (iPS) from human umbilical vein endothelial cells and differentiation of the resulting HiPS back to endothelial cells (Ec-Diff), as well as neural (Nn-Diff) cell lineage that contained both neurons and astrocytes. Furthermore, the identities of these cell lineages were established by gene array analysis. Here, we explored the same arrays to gain insight into the gene alteration processes that accompany the establishment of endothelial vs. non-endothelial neural cell phenotypes. We compared the expression of genes that code for transcription factors and epigenetic regulators when HiPS is differentiated into these endothelial and non-endothelial lineages. Our in silico analyses have identified cohorts of genes that are similarly up- or downregulated in both lineages, as well as those that exhibit lineage-specific alterations. Based on these results, we propose that genes that are similarly altered in both lineages participate in priming the stem cell for differentiation in a lineage-independent manner, whereas those that are differentially altered in endothelial compared to neural cells participate in a lineage-specific differentiation process. Specific GATA family members and their cofactors and epigenetic regulators (DNMT3B, PRDM14, HELLS) with a major role in regulating DNA methylation were among participants in priming HiPS for lineage-independent differentiation. In addition, we identified distinct cohorts of transcription factors and epigenetic regulators whose alterations correlated specifically with the establishment of endothelial vs. non-endothelial neural lineages.
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Schmitt HM, Fehrman RL, Maes ME, Yang H, Guo LW, Schlamp CL, Pelzel HR, Nickells RW. Increased Susceptibility and Intrinsic Apoptotic Signaling in Neurons by Induced HDAC3 Expression. Invest Ophthalmol Vis Sci 2021; 62:14. [PMID: 34398198 PMCID: PMC8375002 DOI: 10.1167/iovs.62.10.14] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2020] [Accepted: 07/05/2021] [Indexed: 12/12/2022] Open
Abstract
Purpose Inhibition or targeted deletion of histone deacetylase 3 (HDAC3) is neuroprotective in a variety neurodegenerative conditions, including retinal ganglion cells (RGCs) after acute optic nerve damage. Consistent with this, induced HDAC3 expression in cultured cells shows selective toxicity to neurons. Despite an established role for HDAC3 in neuronal pathology, little is known regarding the mechanism of this pathology. Methods Induced expression of an HDAC3-mCherry fusion protein in mouse RGCs was accomplished by transduction with AAV2/2-Pgk-HDAC3-mCherry. Increased susceptibility to optic nerve damage in HDAC3-mCherry expressing RGCs was evaluated in transduced mice that received acute optic nerve crush surgery. Expression of HDAC3-FLAG or HDAC3-mCherry was induced by nucleofection or transfection of plasmids into differentiated or undifferentiated 661W tissue culture cells. Immunostaining for cleaved caspase 3, localization of a GFP-BAX fusion protein, and quantitative RT-PCR was used to evaluate HDAC3-induced damage. Results Induced expression of exogenous HDAC3 in RGCs by viral-mediated gene transfer resulted in modest levels of cell death but significantly increased the sensitivity of these neurons to axonal damage. Undifferentiated 661W retinal precursor cells were resilient to induced HDAC3 expression, but after differentiation, HDAC3 induced GFP-BAX recruitment to the mitochondria and BAX/BAK dependent activation of caspase 3. This was accompanied by an increase in accumulation of transcripts for the JNK2/3 kinases and the p53-regulated BH3-only gene Bbc3/Puma. Cell cycle arrest of undifferentiated 661W cells did not increase their sensitivity to HDAC3 expression. Conclusions Collectively, these results indicate that HDAC3-induced toxicity to neurons is mediated by the intrinsic apoptotic pathway.
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Affiliation(s)
- Heather M. Schmitt
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison WI, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
- Department of Ophthalmology, Duke University, Durham, NC, United States
| | - Rachel L. Fehrman
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison WI, United States
| | - Margaret E. Maes
- Institute of Science and Technology Austria, Klosterneuburg, Austria
| | - Huan Yang
- Department of Surgery, University of Wisconsin-Madison, Madison, WI, United States
| | - Lian-Wang Guo
- Department of Surgery, University of Virginia School of Medicine, Charlottesville, VA, United States
| | - Cassandra L. Schlamp
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison WI, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
| | - Heather R. Pelzel
- Department of Biological Sciences, University of Wisconsin-Whitewater, Whitewater, WI, United States
| | - Robert W. Nickells
- Department of Ophthalmology and Visual Sciences, University of Wisconsin-Madison, Madison WI, United States
- McPherson Eye Research Institute, University of Wisconsin-Madison, Madison, WI, United States
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Nicholson C, Ishii M, Annamalai B, Chandler K, Chwa M, Kenney MC, Shah N, Rohrer B. J or H mtDNA haplogroups in retinal pigment epithelial cells: Effects on cell physiology, cargo in extracellular vesicles, and differential uptake of such vesicles by naïve recipient cells. Biochim Biophys Acta Gen Subj 2021; 1865:129798. [PMID: 33217521 PMCID: PMC8396072 DOI: 10.1016/j.bbagen.2020.129798] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2020] [Revised: 10/19/2020] [Accepted: 10/23/2020] [Indexed: 01/11/2023]
Abstract
PURPOSE Extracellular vesicles (EVs) are predicted to represent the internal state of cells. In polarized RPE monolayers, EVs can mediate long-distance communication, requiring endocytosis via protein-protein interactions. EV uptake from oxidatively stressed donor cells triggers loss in transepithelial resistance (TER) in recipient monolayers mediated by HDAC6. Here, we examine EVs released from RPE cells with identical nuclear genes but different mitochondrial (mt)DNA haplogroups (H, J). J-cybrids produce less ATP, and the J-haplogroup is associated with a higher risk for age-related macular degeneration. METHODS Cells were grown as mature monolayers to either collect EVs from apical surfaces or to serve as naïve recipient cells. Transfer assays, transferring EVs to a recipient monolayer were performed, monitoring TER and EV-uptake. The presence of known EV surface proteins was quantified by protein chemistry. RESULTS H- and J-cybrids were confirmed to exhibit different levels of TER and energy metabolism. EVs from J-cybrids reduced TER in recipient ARPE-19 cells, whereas EVs from H-cybrids were ineffective. TER reduction was mediated by HDAC6 activity, and EV uptake required interaction between integrin and its ligands and surface proteoglycans. Protein quantifications confirmed elevated levels of fibronectin and annexin A2 on J-cybrid EVs. CONCLUSIONS We speculate that RPE EVs have a finite set of ligands (membrane proteoglycans and integrins and/or annexin A2) that are elevated in EVs from stressed cells; and that if EVs released by the RPE could be captured from serum, that they might provide a disease biomarker of RPE-dependent diseases.
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Affiliation(s)
- Crystal Nicholson
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Masaaki Ishii
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Balasubramaniam Annamalai
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Kyrie Chandler
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Marilyn Chwa
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California Irvine, Irvine, CA 92697, United States of America
| | - M Cristina Kenney
- Gavin Herbert Eye Institute, Department of Ophthalmology, University of California Irvine, Irvine, CA 92697, United States of America
| | - Navjot Shah
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States of America; Department of Neurosciences Medical University of South Carolina, Charleston, SC 29425, United States of America; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, United States of America.
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Vilema-Enríquez G, Quinlan R, Kilfeather P, Mazzone R, Saqlain S, Del Molino Del Barrio I, Donato A, Corda G, Li F, Vedadi M, Németh AH, Brennan PE, Wade-Martins R. Inhibition of the SUV4-20 H1 histone methyltransferase increases frataxin expression in Friedreich's ataxia patient cells. J Biol Chem 2020; 295:17973-17985. [PMID: 33028632 PMCID: PMC7939392 DOI: 10.1074/jbc.ra120.015533] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/28/2020] [Indexed: 12/11/2022] Open
Abstract
The molecular mechanisms of reduced frataxin (FXN) expression in Friedreich's ataxia (FRDA) are linked to epigenetic modification of the FXN locus caused by the disease-associated GAA expansion. Here, we identify that SUV4-20 histone methyltransferases, specifically SUV4-20 H1, play an important role in the regulation of FXN expression and represent a novel therapeutic target. Using a human FXN-GAA-Luciferase repeat expansion genomic DNA reporter model of FRDA, we screened the Structural Genomics Consortium epigenetic probe collection. We found that pharmacological inhibition of the SUV4-20 methyltransferases by the tool compound A-196 increased the expression of FXN by ∼1.5-fold in the reporter cell line. In several FRDA cell lines and patient-derived primary peripheral blood mononuclear cells, A-196 increased FXN expression by up to 2-fold, an effect not seen in WT cells. SUV4-20 inhibition was accompanied by a reduction in H4K20me2 and H4K20me3 and an increase in H4K20me1, but only modest (1.4-7.8%) perturbation in genome-wide expression was observed. Finally, based on the structural activity relationship and crystal structure of A-196, novel small molecule A-196 analogs were synthesized and shown to give a 20-fold increase in potency for increasing FXN expression. Overall, our results suggest that histone methylation is important in the regulation of FXN expression and highlight SUV4-20 H1 as a potential novel therapeutic target for FRDA.
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Affiliation(s)
| | - Robert Quinlan
- Structural Genomics Consortium, University of Oxford, Oxford, United Kingdom; Alzheimer's Research UK Oxford Drug Discovery Institute, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Peter Kilfeather
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Roberta Mazzone
- Structural Genomics Consortium, University of Oxford, Oxford, United Kingdom; Alzheimer's Research UK Oxford Drug Discovery Institute, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Saba Saqlain
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | | | - Annalidia Donato
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Gabriele Corda
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom
| | - Fengling Li
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada
| | - Masoud Vedadi
- Structural Genomics Consortium, University of Toronto, Toronto, Ontario, Canada; Department of Pharmacology and Toxicology, University of Toronto, Toronto, Ontario, Canada
| | - Andrea H Németh
- Nuffield Department of Clinical Neurosciences, University of Oxford, Oxford, United Kingdom; Oxford Centre for Genomic Medicine, Oxford University Hospitals National Health Service Trust, Oxford, United Kingdom
| | - Paul E Brennan
- Structural Genomics Consortium, University of Oxford, Oxford, United Kingdom; Alzheimer's Research UK Oxford Drug Discovery Institute, Target Discovery Institute, Nuffield Department of Medicine, University of Oxford, Oxford, United Kingdom
| | - Richard Wade-Martins
- Department of Physiology, Anatomy and Genetics, University of Oxford, Oxford, United Kingdom.
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Zhang K, Zhao H, Zhang K, Hua C, Qin X, Xu S. Chromatin-regulating genes are associated with postoperative prognosis and isocitrate dehydrogenase mutation in astrocytoma. ANNALS OF TRANSLATIONAL MEDICINE 2020; 8:1594. [PMID: 33437793 PMCID: PMC7791220 DOI: 10.21037/atm-20-7229] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
Background Abnormality in chromatin regulation is a major determinant in the progression of multiple neoplasms. Astrocytoma is a malignant histologic morphology of glioma that is commonly accompanied by chromatin dysregulation. However, the systemic interpretation of the expression characteristics of chromatin-regulating genes in astrocytoma is unclear. Methods In this study, we investigated the expression profile of chromatin regulation genes in 194 astrocytoma patients sourced from The Cancer Genome Atlas (TCGA) database. The relevance of gene expression and postoperative survival outcomes was assessed. Results Based on the expression patterns of chromatin regulation genes, two primary clusters and three subclusters with significantly different survival outcomes were identified. The patients in cluster_1 (or subcluster_1) had a poorer prognosis than the other groups, and this particular cohort were older, with a more advanced grade of tumor and isocitrate dehydrogenase-wildtype distribution. Detection of the differentially expressed genes revealed that the group with poor prognosis was characterized by downregulation of H2AFY2, WAC, HDAC5, ZMYND11, TET1, SATB1, and MYST4, and overexpression of EYA4. Moreover, all eight genes were significantly correlated with overall survival (OS) in astrocytoma. Age-associated genes were investigated and the expression levels of EYA4, TET1, SATB1, WAC, ZMYND11, and H2AFY2 were found to be closely correlated with advanced age. Regression analysis suggested that the expression levels of H2AFY2, HILS1, EYA1, EYA4, and KDM5B were independently associated with IDH mutation status. The differential expressions of 34 common genes were significantly associated with age, grade, and IDH mutant. Conclusions The study revealed that the expression pattern of chromatin regulation genes was significantly associated with postoperative prognosis in astrocytoma. Moreover, the differential expression of particular genes was strongly associated with clinical characteristics such as age, grade, and IDH subtype. These results suggest that the genes involved in chromatin regulation play important roles in the biological process of astrocytoma progression, and these molecules could potentially serve as therapeutic targets in astrocytoma.
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Affiliation(s)
- Kun Zhang
- Jilin Provincial Key Laboratory on Molecular and Chemical Genetic, The Second Hospital of Jilin University, Changchun, China
| | - Hongguang Zhao
- Department of Nuclear Medicine, The First Hospital of Jilin University, Changchun, China
| | - Kewei Zhang
- Department of Thoracic Surgery, The First Hospital of Jilin University, Changchun, China
| | - Cong Hua
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, China
| | - Xiaowei Qin
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, China
| | - Songbai Xu
- Department of Neurosurgery, The First Hospital of Jilin University, Changchun, China
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Cappellacci L, Perinelli DR, Maggi F, Grifantini M, Petrelli R. Recent Progress in Histone Deacetylase Inhibitors as Anticancer Agents. Curr Med Chem 2020; 27:2449-2493. [PMID: 30332940 DOI: 10.2174/0929867325666181016163110] [Citation(s) in RCA: 71] [Impact Index Per Article: 17.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/21/2018] [Revised: 07/29/2018] [Accepted: 10/09/2018] [Indexed: 12/13/2022]
Abstract
Histone Deacetylase (HDAC) inhibitors are a relatively new class of anti-cancer agents that play important roles in epigenetic or non-epigenetic regulation, inducing death, apoptosis, and cell cycle arrest in cancer cells. Recently, their use has been clinically validated in cancer patients resulting in the approval by the FDA of four HDAC inhibitors, vorinostat, romidepsin, belinostat and panobinostat, used for the treatment of cutaneous/peripheral T-cell lymphoma and multiple myeloma. Many more HDAC inhibitors are at different stages of clinical development for the treatment of hematological malignancies as well as solid tumors. Also, clinical trials of several HDAC inhibitors for use as anti-cancer drugs (alone or in combination with other anti-cancer therapeutics) are ongoing. In the intensifying efforts to discover new, hopefully, more therapeutically efficacious HDAC inhibitors, molecular modelingbased rational drug design has played an important role. In this review, we summarize four major structural classes of HDAC inhibitors (hydroxamic acid derivatives, aminobenzamide, cyclic peptide and short-chain fatty acids) 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.
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Affiliation(s)
- Loredana Cappellacci
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Diego R Perinelli
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Filippo Maggi
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Mario Grifantini
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
| | - Riccardo Petrelli
- School of Pharmacy, Medicinal Chemistry Unit, University of Camerino, Via S. Agostino 1, 62032 Camerino, Italy
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11
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Investigating developmental and disease mechanisms of the cerebellum with pluripotent stem cells. Mol Cell Neurosci 2020; 107:103530. [PMID: 32693017 DOI: 10.1016/j.mcn.2020.103530] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 04/15/2020] [Accepted: 07/15/2020] [Indexed: 01/02/2023] Open
Abstract
The cerebellum is a brain region located in the dorsal part of the anterior hindbrain, composed of a highly stereotyped neural circuit structure with small sets of neurons. The cerebellum is involved in a wide variety of functions such as motor control, learning, cognition and others. Damage to the cerebellum often leads to impairments in motor skills (cerebellar ataxia). Cerebellar ataxia can occur as a result of neurodegenerative diseases such as spinocerebellar ataxia. Recent advances in technologies related to pluripotent stem cells and their neural differentiation has enabled researchers to investigate the mechanisms of development and of disease in the human brain. Here, we review recent applications of leading-edge stem cell technologies to the mechanistic investigation of human cerebellar development and neurological diseases affecting the cerebellum.
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Abstract
IMPACT STATEMENT Brain development and degeneration are highly complex processes that are regulated by a large number of molecules and signaling pathways the identities of which are being unraveled. Accumulating evidence points to histone deacetylases and epigenetic mechanisms as being important regulators of these processes. In this review, we describe that histone deacetylase-3 (HDAC3) is a particularly crucial regulator of both neurodevelopment and neurodegeneration. In addition, HDAC3 regulates memory formation, synaptic plasticity, and the cognitive impairment associated with normal aging. Understanding how HDAC3 functions contributes to the normal development and functioning of the brain while also promoting neurodegeneration could lead to the development of therapeutic approaches for neurodevelopmental, neuropsychiatric, and neurodegenerative disorders.
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13
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Gottesfeld JM. Molecular Mechanisms and Therapeutics for the GAA·TTC Expansion Disease Friedreich Ataxia. Neurotherapeutics 2019; 16:1032-1049. [PMID: 31317428 PMCID: PMC6985418 DOI: 10.1007/s13311-019-00764-x] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022] Open
Abstract
Friedreich ataxia (FRDA), the most common inherited ataxia, is caused by transcriptional silencing of the nuclear FXN gene, encoding the essential mitochondrial protein frataxin. Currently, there is no approved therapy for this fatal disorder. Gene silencing in FRDA is due to hyperexpansion of the triplet repeat sequence GAA·TTC in the first intron of the FXN gene, which results in chromatin histone modifications consistent with heterochromatin formation. Frataxin is involved in mitochondrial iron homeostasis and the assembly and transfer of iron-sulfur clusters to various mitochondrial enzymes and components of the electron transport chain. Frataxin insufficiency leads to progressive spinocerebellar neurodegeneration, causing symptoms of gait and limb ataxia, slurred speech, muscle weakness, sensory loss, and cardiomyopathy in many patients, resulting in death in early adulthood. Numerous approaches are being taken to find a treatment for FRDA, including excision or correction of the repeats by genome engineering methods, gene activation with small molecules or artificial transcription factors, delivery of frataxin to affected cells by protein replacement therapy, gene therapy, or small molecules to increase frataxin protein levels, and therapies aimed at countering the cellular consequences of reduced frataxin. This review will summarize the mechanisms involved in repeat-mediated gene silencing and recent efforts aimed at development of therapeutics.
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Affiliation(s)
- Joel M Gottesfeld
- Department of Molecular Medicine, The Scripps Research Institute, La Jolla, California, 92037, USA.
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Świtońska K, Szlachcic WJ, Handschuh L, Wojciechowski P, Marczak Ł, Stelmaszczuk M, Figlerowicz M, Figiel M. Identification of Altered Developmental Pathways in Human Juvenile HD iPSC With 71Q and 109Q Using Transcriptome Profiling. Front Cell Neurosci 2019; 12:528. [PMID: 30713489 PMCID: PMC6345698 DOI: 10.3389/fncel.2018.00528] [Citation(s) in RCA: 24] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2018] [Accepted: 12/19/2018] [Indexed: 12/29/2022] Open
Abstract
In Huntington disease (HD) subtle symptoms in patients may occur years or even decades prior to diagnosis. HD changes at a molecular level may begin as early as in cells that are non-lineage committed such as stem cells or HD patients induced pluripotent stem cells (iPSCs) offering opportunity to enhance the understanding of the HD pathogenesis. In addition, juvenile HD non-linage committed cells were previously not directly investigated in detail by RNA-seq. In the present manuscript, we define the early HD and juvenile HD transcriptional alterations using 6 human HD iPS cell lines from two patients, one with 71 CAGs and one with 109 CAG repeats. We identified 107 (6 HD lines), 198 (3 HD71Q lines) and 217 (3 HD109Q lines) significantly dysregulated mRNAs in each comparison group. The analyses showed that many of dysregulated transcripts in HD109Q iPSC lines are involved in DNA damage response and apoptosis, such as CCND1, CDKN1A, TP53, BAX, TNFRSF10B, TNFRSF10C, TNFRSF10D, DDB2, PLCB1, PRKCQ, HSH2D, ZMAT3, PLK2, and RPS27L. Most of them were identified as downregulated and their proteins are direct interactors with TP53. HTT probably alters the level of several TP53 interactors influencing apoptosis. This may lead to accumulation of an excessive number of progenitor cells and potential disruption of cell differentiation and production of mature neurons. In addition, HTT effects on cell polarization also demonstrated in the analysis may result in a generation of incorrect progenitors. Bioinformatics analysis of transcripts dysregulated in HD71Q iPSC lines showed that several of them act as transcription regulators during the early multicellular stages of development, such as ZFP57, PIWIL2, HIST1H3C, and HIST1H2BB. Significant upregulation of most of these transcripts may lead to a global increase in expression level of genes involved in pathways critical for embryogenesis and early neural development. In addition, MS analysis revealed altered levels of TP53 and ZFP30 proteins reflecting the functional significance of dysregulated mRNA levels of these proteins which were associated with apoptosis and DNA binding. Our finding very well corresponds to the fact that mutation in the HTT gene may cause precocious neurogenesis and identifies pathways likely disrupted during development.
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Affiliation(s)
- Karolina Świtońska
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
| | | | - Luiza Handschuh
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
| | - Paweł Wojciechowski
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland.,Institute of Computing Science, Poznan University of Technology, Poznań, Poland
| | - Łukasz Marczak
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
| | - Michał Stelmaszczuk
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
| | - Marek Figlerowicz
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
| | - Maciej Figiel
- Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznań, Poland
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15
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Schreiber AM, Misiorek JO, Napierala JS, Napierala M. Progress in understanding Friedreich's ataxia using human induced pluripotent stem cells. Expert Opin Orphan Drugs 2019; 7:81-90. [PMID: 30828501 DOI: 10.1080/21678707.2019.1562334] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 01/02/2023]
Abstract
Introduction Friedreich's ataxia (FRDA) is an autosomal recessive multisystem disease mainly affecting the peripheral and central nervous systems, and heart. FRDA is caused by a GAA repeat expansion in the first intron of the frataxin (FXN) gene, that leads to reduced expression of FXN mRNA and frataxin protein. Neuronal and cardiac cells are primary targets of frataxin deficiency and generating models via differentiation of induced pluripotent stem cells (iPSCs) into these cell types is essential for progress towards developing therapies for FRDA. Areas covered This review is focused on modeling FRDA using human iPSCs and various iPSC-differentiated cell types. We emphasized the importance of patient and corrected isogenic cell line pairs to minimize effects caused by biological variability between individuals. Expert opinion The versatility of iPSC-derived cellular models of FRDA is advantageous for developing new therapeutic strategies, and rigorous testing in such models will be critical for approval of the first treatment for FRDA. Creating a well-characterized and diverse set of iPSC lines, including appropriate isogenic controls, will facilitate achieving this goal. Also, improvement of differentiation protocols, especially towards proprioceptive sensory neurons and organoid generation, is necessary to utilize the full potential of iPSC technology in the drug discovery process.
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Affiliation(s)
- Anna M Schreiber
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Julia O Misiorek
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
| | - Jill S Napierala
- Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham AL, United States
| | - Marek Napierala
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland.,Department of Biochemistry and Molecular Genetics, University of Alabama at Birmingham, Birmingham AL, United States
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16
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Shah N, Ishii M, Brandon C, Ablonczy Z, Cai J, Liu Y, Chou CJ, Rohrer B. Extracellular vesicle-mediated long-range communication in stressed retinal pigment epithelial cell monolayers. Biochim Biophys Acta Mol Basis Dis 2018; 1864:2610-2622. [PMID: 29684588 DOI: 10.1016/j.bbadis.2018.04.016] [Citation(s) in RCA: 57] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/11/2018] [Revised: 04/03/2018] [Accepted: 04/17/2018] [Indexed: 02/06/2023]
Abstract
Retinal pigment epithelium (RPE) alterations in age-related macular degeneration occur in patches, potentially involving long-distance communication between damaged and healthy areas. Communication along the epithelium might be mediated by extracellular vesicles (EVs). To test this hypothesis, EVs were collected from supernatants of polarized ARPE-19 and primary porcine RPE monolayers for functional and biochemical assays. EVs from oxidatively stressed donor cells reduced barrier function in recipient RPE monolayers when compared to control EVs. The effect on barrier function was dependent on EV uptake, which occurred rapidly with EVs from oxidatively stressed donor cells. Mass spectrometry-based proteomic analysis of EVs identified HDAC6, which is known to reduce tight junction stability. Activity assays confirmed the presence of HDAC6 in EVs, and EV transfer assays using HDAC6 inhibitors confirmed its effect in monolayers. These findings demonstrate that EVs can communicate stress messages to healthy RPE cells, potentially contributing to RPE dysfunction.
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Affiliation(s)
- Navjot Shah
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, United States
| | - Masakii Ishii
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, United States
| | - Carlene Brandon
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Zsolt Ablonczy
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Jingwen Cai
- Cellular Biology & Anatomy, Augusta University, Augusta, GA 30912, United States
| | - Yutao Liu
- Cellular Biology & Anatomy, Augusta University, Augusta, GA 30912, United States
| | - C James Chou
- Department of Drug Discovery, Medical University of South Carolina, Charleston, SC 29425, United States
| | - Bärbel Rohrer
- Department of Ophthalmology, Medical University of South Carolina, Charleston, SC 29425, United States; Ralph H. Johnson VA Medical Center, Charleston, SC 29401, United States; Department of Neurosciences, Medical University of South Carolina, Charleston, SC 29425, United States.
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17
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Edenharter O, Clement J, Schneuwly S, Navarro JA. Overexpression of Drosophila frataxin triggers cell death in an iron-dependent manner. J Neurogenet 2017; 31:189-202. [PMID: 28838288 DOI: 10.1080/01677063.2017.1363200] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/31/2017] [Indexed: 10/24/2022]
Abstract
Friedreich ataxia (FRDA) is the most important autosomal recessive ataxia in the Caucasian population. FRDA patients display severe neurological and cardiac symptoms that reflect a strong cellular and axonal degeneration. FRDA is caused by a loss of function of the mitochondrial protein frataxin which impairs the biosynthesis of iron-sulfur clusters and in turn the catalytic activity of several enzymes in the Krebs cycle and the respiratory chain leading to a diminished energy production. Although FRDA is due to frataxin depletion, overexpression might also be very helpful to better understand cellular functions of frataxin. In this work, we have increased frataxin expression in neurons to elucidate specific roles that frataxin might play in these tissues. Using molecular, biochemical, histological and behavioral methods, we report that frataxin overexpression is sufficient to increase oxidative phosphorylation, modify mitochondrial morphology, alter iron homeostasis and trigger oxidative stress-dependent cell death. Interestingly, genetic manipulation of mitochondrial iron metabolism by silencing mitoferrin successfully improves cell survival under oxidative-attack conditions, although enhancing antioxidant defenses or mitochondrial fusion failed to ameliorate frataxin overexpression phenotypes. This result suggests that cell degeneration is directly related to enhanced incorporation of iron into the mitochondria. Drosophila frataxin overexpression might also provide an alternative approach to identify processes that are important in FRDA such as changes in mitochondrial morphology and oxidative stress induced cell death.
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Affiliation(s)
- Oliver Edenharter
- a Institute of Zoology , University of Regensburg , Regensburg , Germany
| | - Janik Clement
- a Institute of Zoology , University of Regensburg , Regensburg , Germany
| | - Stephan Schneuwly
- a Institute of Zoology , University of Regensburg , Regensburg , Germany
| | - Juan A Navarro
- a Institute of Zoology , University of Regensburg , Regensburg , Germany
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18
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She A, Kurtser I, Reis SA, Hennig K, Lai J, Lang A, Zhao WN, Mazitschek R, Dickerson BC, Herz J, Haggarty SJ. Selectivity and Kinetic Requirements of HDAC Inhibitors as Progranulin Enhancers for Treating Frontotemporal Dementia. Cell Chem Biol 2017; 24:892-906.e5. [PMID: 28712747 DOI: 10.1016/j.chembiol.2017.06.010] [Citation(s) in RCA: 28] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 02/06/2017] [Accepted: 06/19/2017] [Indexed: 11/18/2022]
Abstract
Frontotemporal dementia (FTD) arises from neurodegeneration in the frontal, insular, and anterior temporal lobes. Autosomal dominant causes of FTD include heterozygous mutations in the GRN gene causing haploinsufficiency of progranulin (PGRN) protein. Recently, histone deacetylase (HDAC) inhibitors have been identified as enhancers of PGRN expression, although the mechanisms through which GRN is epigenetically regulated remain poorly understood. Using a chemogenomic toolkit, including optoepigenetic probes, we show that inhibition of class I HDACs is sufficient to upregulate PGRN in human neurons, and only inhibitors with apparent fast binding to their target HDAC complexes are capable of enhancing PGRN expression. Moreover, we identify regions in the GRN promoter in which elevated H3K27 acetylation and transcription factor EB (TFEB) occupancy correlate with HDAC-inhibitor-mediated upregulation of PGRN. These findings have implications for epigenetic and cis-regulatory mechanisms controlling human GRN expression and may advance translational efforts to develop targeted therapeutics for treating PGRN-deficient FTD.
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Affiliation(s)
- Angela She
- Chemical Neurobiology Laboratory, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Center for Genomic Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Iren Kurtser
- Chemical Neurobiology Laboratory, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Center for Genomic Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Surya A Reis
- Chemical Neurobiology Laboratory, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Center for Genomic Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Krista Hennig
- Chemical Neurobiology Laboratory, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Center for Genomic Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Jenny Lai
- Chemical Neurobiology Laboratory, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Center for Genomic Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Audrey Lang
- Chemical Neurobiology Laboratory, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Center for Genomic Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Wen-Ning Zhao
- Chemical Neurobiology Laboratory, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Center for Genomic Medicine, Harvard Medical School, Boston, MA 02114, USA
| | - Ralph Mazitschek
- Center for Systems Biology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Bradford C Dickerson
- MGH Frontotemporal Disorders Unit, Gerontology Research Unit, Alzheimer's Disease Research Center, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
| | - Joachim Herz
- Departments of Molecular Genetics, Neuroscience, Neurology and Neurotherapeutics, University of Texas Southwestern Medical Center at Dallas, Dallas, TX 75390-9046, USA
| | - Stephen J Haggarty
- Chemical Neurobiology Laboratory, Departments of Neurology & Psychiatry, Massachusetts General Hospital, Center for Genomic Medicine, Harvard Medical School, Boston, MA 02114, USA.
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19
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Polak U, Li Y, Butler JS, Napierala M. Alleviating GAA Repeat Induced Transcriptional Silencing of the Friedreich's Ataxia Gene During Somatic Cell Reprogramming. Stem Cells Dev 2016; 25:1788-1800. [PMID: 27615158 PMCID: PMC5155629 DOI: 10.1089/scd.2016.0147] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/01/2016] [Accepted: 09/09/2016] [Indexed: 12/13/2022] Open
Abstract
Friedreich's ataxia (FRDA) is the most common autosomal recessive ataxia. This severe neurodegenerative disease is caused by an expansion of guanine-adenine-adenine (GAA) repeats located in the first intron of the frataxin (FXN) gene, which represses its transcription. Although transcriptional silencing is associated with heterochromatin-like changes in the vicinity of the expanded GAAs, the exact mechanism and pathways involved in transcriptional inhibition are largely unknown. As major remodeling of the epigenome is associated with somatic cell reprogramming, modulating chromatin modification pathways during the cellular transition from a somatic to a pluripotent state is likely to generate permanent changes to the epigenetic landscape. We hypothesize that the epigenetic modifications in the vicinity of the GAA repeats can be reversed by pharmacological modulation during somatic cell reprogramming. We reprogrammed FRDA fibroblasts into induced pluripotent stem cells (iPSCs) in the presence of various small molecules that target DNA methylation and histone acetylation and methylation. Treatment of FRDA iPSCs with two compounds, sodium butyrate (NaB) and Parnate, led to an increase in FXN expression and correction of repressive marks at the FXN locus, which persisted for several passages. However, prolonged culture of the epigenetically modified FRDA iPSCs led to progressive expansions of the GAA repeats and a corresponding decrease in FXN expression. Furthermore, we uncovered that differentiation of these iPSCs into neurons also results in resilencing of the FXN gene. Taken together, these results demonstrate that transcriptional repression caused by long GAA repeat tracts can be partially or transiently reversed by altering particular epigenetic modifications, thus revealing possibilities for detailed analyses of silencing mechanism and development of new therapeutic approaches for FRDA.
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Affiliation(s)
- Urszula Polak
- Department of Molecular Carcinogenesis, Center for Cancer Epigenetics, University of Texas MD Anderson Cancer Center, Smithville, Texas
| | - Yanjie Li
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama
| | - Jill Sergesketter Butler
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama
| | - Marek Napierala
- Department of Biochemistry and Molecular Genetics, UAB Stem Cell Institute, University of Alabama at Birmingham, Birmingham, Alabama
- Department of Molecular Biomedicine, Institute of Bioorganic Chemistry, Polish Academy of Sciences, Poznan, Poland
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20
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Abstract
INTRODUCTION Friedreich's ataxia (FRDA) is an autosomal recessive neurodegenerative disease caused by expansion of a GAA·TTC triplet in the first intron of the FXN gene, encoding the essential mitochondrial protein frataxin. Repeat expansion results in transcriptional silencing through an epigenetic mechanism, resulting in significant decreases in frataxin protein in affected individuals. Since the FXN protein coding sequence is unchanged in FRDA, an attractive therapeutic approach for this disease would be to increase transcription of pathogenic alleles with small molecules that target the silencing mechanism. AREAS COVERED We review the evidence that histone postsynthetic modifications and heterochromatin formation are responsible for FXN gene silencing in FRDA, along with efforts to reverse silencing with drugs that target histone modifying enzymes. Chemical and pharmacological properties of histone deacetylase (HDAC) inhibitors, which reverse silencing, together with enzyme target profiles and kinetics of inhibition, are discussed. Two HDAC inhibitors have been studied in human clinical trials and the properties of these compounds are compared and contrasted. Efforts to improve on bioavailability, metabolic stability, and target activity are reviewed. EXPERT OPINION 2-aminobenzamide class I HDAC inhibitors are attractive therapeutic small molecules for FRDA. These molecules increase FXN gene expression in human neuronal cells derived from patient induced pluripotent stem cells, and in two mouse models for the disease, as well as in circulating lymphocytes in patients treated in a phase Ib clinical trial. Medicinal chemistry efforts have identified compounds with improved brain penetration, metabolic stability and efficacy in the human neuronal cell model. A clinical candidate will soon be identified for further human testing.
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Affiliation(s)
- Elisabetta Soragni
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California 92037 USA
| | - Joel M Gottesfeld
- Department of Cell and Molecular Biology, The Scripps Research Institute, La Jolla, California 92037 USA
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21
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Chutake YK, Lam CC, Costello WN, Anderson MP, Bidichandani SI. Reversal of epigenetic promoter silencing in Friedreich ataxia by a class I histone deacetylase inhibitor. Nucleic Acids Res 2016; 44:5095-104. [PMID: 26896803 PMCID: PMC4914082 DOI: 10.1093/nar/gkw107] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/28/2015] [Revised: 02/13/2016] [Accepted: 02/15/2016] [Indexed: 12/27/2022] Open
Abstract
Friedreich ataxia, the most prevalent inherited ataxia, is caused by an expanded GAA triplet-repeat sequence in intron 1 of the FXN gene. Repressive chromatin spreads from the expanded GAA triplet-repeat sequence to cause epigenetic silencing of the FXN promoter via altered nucleosomal positioning and reduced chromatin accessibility. Indeed, deficient transcriptional initiation is the predominant cause of transcriptional deficiency in Friedreich ataxia. Treatment with 109, a class I histone deacetylase (HDAC) inhibitor, resulted in increased level of FXN transcript both upstream and downstream of the expanded GAA triplet-repeat sequence, without any change in transcript stability, suggesting that it acts via improvement of transcriptional initiation. Quantitative analysis of transcriptional initiation via metabolic labeling of nascent transcripts in patient-derived cells revealed a >3-fold increase (P < 0.05) in FXN promoter function. A concomitant 3-fold improvement (P < 0.001) in FXN promoter structure and chromatin accessibility was observed via Nucleosome Occupancy and Methylome Sequencing, a high-resolution in vivo footprint assay for detecting nucleosome occupancy in individual chromatin fibers. No such improvement in FXN promoter function or structure was observed upon treatment with a chemically-related inactive compound (966). Thus epigenetic promoter silencing in Friedreich ataxia is reversible, and the results implicate class I HDACs in repeat-mediated promoter silencing.
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Affiliation(s)
- Yogesh K Chutake
- Department of Pediatrics, University of Oklahoma College of Medicine, Oklahoma City, OK 73104, USA
| | - Christina C Lam
- Department of Pediatrics, University of Oklahoma College of Medicine, Oklahoma City, OK 73104, USA
| | - Whitney N Costello
- Department of Pediatrics, University of Oklahoma College of Medicine, Oklahoma City, OK 73104, USA
| | - Michael P Anderson
- Department of Biochemistry & Molecular Biology, University of Oklahoma College of Medicine, Oklahoma City, OK 73104, USA
| | - Sanjay I Bidichandani
- Department of Pediatrics, University of Oklahoma College of Medicine, Oklahoma City, OK 73104, USA Department of Biostatistics & Epidemiology, University of Oklahoma College of Public Health, Oklahoma City, OK 73104, USA
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22
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Advancing drug discovery for neuropsychiatric disorders using patient-specific stem cell models. Mol Cell Neurosci 2016; 73:104-15. [PMID: 26826498 DOI: 10.1016/j.mcn.2016.01.011] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2015] [Revised: 01/22/2016] [Accepted: 01/25/2016] [Indexed: 12/17/2022] Open
Abstract
Compelling clinical, social, and economic reasons exist to innovate in the process of drug discovery for neuropsychiatric disorders. The use of patient-specific, induced pluripotent stem cells (iPSCs) now affords the ability to generate neuronal cell-based models that recapitulate key aspects of human disease. In the context of neuropsychiatric disorders, where access to physiologically active and relevant cell types of the central nervous system for research is extremely limiting, iPSC-derived in vitro culture of human neurons and glial cells is transformative. Potential applications relevant to early stage drug discovery, include support of quantitative biochemistry, functional genomics, proteomics, and perhaps most notably, high-throughput and high-content chemical screening. While many phenotypes in human iPSC-derived culture systems may prove adaptable to screening formats, addressing the question of which in vitro phenotypes are ultimately relevant to disease pathophysiology and therefore more likely to yield effective pharmacological agents that are disease-modifying treatments requires careful consideration. Here, we review recent examples of studies of neuropsychiatric disorders using human stem cell models where cellular phenotypes linked to disease and functional assays have been reported. We also highlight technical advances using genome-editing technologies in iPSCs to support drug discovery efforts, including the interpretation of the functional significance of rare genetic variants of unknown significance and for the purpose of creating cell type- and pathway-selective functional reporter assays. Additionally, we evaluate the potential of in vitro stem cell models to investigate early events of disease pathogenesis, in an effort to understand the underlying molecular mechanism, including the basis of selective cell-type vulnerability, and the potential to create new cell-based diagnostics to aid in the classification of patients and subsequent selection for clinical trials. A number of key challenges remain, including the scaling of iPSC models to larger cohorts and integration with rich clinicopathological information and translation of phenotypes. Still, the overall use of iPSC-based human cell models with functional cellular and biochemical assays holds promise for supporting the discovery of next-generation neuropharmacological agents for the treatment and ultimately prevention of a range of severe mental illnesses.
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