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Nong Y, Hou Y, Pu Y, Li S, Lan Y. Development and Validation of High-Content Analysis for Screening HDAC6-Selective Inhibitors. SLAS DISCOVERY 2021; 26:628-641. [PMID: 33783263 DOI: 10.1177/24725552211002463] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Throughout recent decades, histone deacetylase (HDAC) inhibitors have shown encouraging potential in cancer treatment, and several pan-HDAC inhibitors have been approved for treating malignant cancers. Numerous adverse effects of pan-HDAC inhibitors have been reported, however, during preclinical and clinical evaluations. To avoid undesirable responses, an increasing number of investigations are focusing on the development of isotype-selective HDAC inhibitors. In this study, we present an effective and quantitative cellular assay using high-content analysis (HCA) to determine compounds' inhibition of the activity of HDAC6 and Class I HDAC isoforms, by detecting the acetylation of their corresponding substrates (i.e., α-tubulin and histone H3). Several conditions that are critical for HCA assays, such as cell seeding number, fixation and permeabilization reagent, and antibody dilution, have been fully validated in this study. We used selective HDAC6 inhibitors and inhibitors targeting different HDAC isoforms to optimize and validate the capability of the HCA assay. The results indicated that the HCA assay is a robust assay for quantifying compounds' selectivity of HDAC6 and Class I HDAC isoforms in cells. Moreover, we screened a panel of compounds for HDAC6 selectivity using this HCA assay, which provided valuable information for the structure-activity relationship (SAR). In summary, our results suggest that the HCA assay is a powerful tool for screening selective HDAC6 inhibitors.
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Affiliation(s)
- Yunhong Nong
- Discovery Project Unit, HitGen, Chengdu, Sichuan, China
| | - Yanyan Hou
- Discovery Project Unit, HitGen, Chengdu, Sichuan, China
| | - Yuting Pu
- Discovery Project Unit, HitGen, Chengdu, Sichuan, China
| | - Si Li
- Discovery Project Unit, HitGen, Chengdu, Sichuan, China
| | - Yan Lan
- Discovery Project Unit, HitGen, Chengdu, Sichuan, China
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2
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Okechukwu C. Deciphering and manipulating the epigenome for the treatment of Parkinson’s and Alzheimer’s disease. MGM JOURNAL OF MEDICAL SCIENCES 2021. [DOI: 10.4103/mgmj.mgmj_90_20] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/04/2022] Open
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3
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Narayan P, Reid S, Scotter EL, McGregor AL, Mehrabi NF, Singh-Bains MK, Glass M, Faull RLM, Snell RG, Dragunow M. Inconsistencies in histone acetylation patterns among different HD model systems and HD post-mortem brains. Neurobiol Dis 2020; 146:105092. [PMID: 32979507 DOI: 10.1016/j.nbd.2020.105092] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2020] [Revised: 08/28/2020] [Accepted: 09/21/2020] [Indexed: 01/10/2023] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG trinucleotide repeat expansion in exon 1 of the huntingtin gene. Emerging evidence shows that additional epigenetic factors can modify disease phenotypes. Harnessing the ability of the epigenome to modify the disease for therapeutic purposes is therefore of interest. Epigenome modifiers, such as histone deacetylase inhibitors (HDACi), have improved pathology in a range of HD models. Yet in clinical trials, HDACi have failed to alleviate HD symptoms in patients. This study investigated potential reasons for the lack of translation of the therapeutic benefits of HDACi from lab to clinic. We analysed histone acetylation patterns of immuno-positive nuclei from brain sections and tissue microarrays from post-mortem human control and HD cases alongside several well-established HD models (OVT73 transgenic HD sheep, YAC128 mice, and an in vitro cell model expressing 97Q mutant huntingtin). Significant increases in histone H4 acetylation were observed in post-mortem HD cases, OVT73 transgenic HD sheep and in vitro models; these changes were absent in YAC128 mice. In addition, nuclear labelling for acetyl-histone H4 levels were inversely proportional to mutant huntingtin aggregate load in HD human cortex. Our data raise concerns regarding the utility of HDACi for the treatment of HD when regions of pathology exhibit already elevated histone acetylation patterns and emphasize the importance of searching for alternative epigenetic targets in future therapeutic strategies aiming to rescue HD phenotypes.
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Affiliation(s)
- Pritika Narayan
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Suzanne Reid
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Emma L Scotter
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand.
| | - Ailsa L McGregor
- School of Pharmacy, University of Otago, Dunedin 9016, New Zealand.
| | - Nasim F Mehrabi
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand.
| | | | - Michelle Glass
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; Department of Pharmacology and Toxicology, University of Otago, Dunedin 9016, New Zealand.
| | - Richard L M Faull
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand.
| | - Russell G Snell
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand; School of Biological Sciences, University of Auckland, Auckland 1010, New Zealand.
| | - Mike Dragunow
- Centre for Brain Research, University of Auckland, Auckland 1023, New Zealand.
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4
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Altered microglia and neurovasculature in the Alzheimer's disease cerebellum. Neurobiol Dis 2019; 132:104589. [PMID: 31454549 DOI: 10.1016/j.nbd.2019.104589] [Citation(s) in RCA: 35] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 07/30/2019] [Accepted: 08/23/2019] [Indexed: 12/12/2022] Open
Abstract
Traditionally regarded to coordinate movement, the cerebellum also exerts non-motor functions including the regulation of cognitive and behavioral processing, suggesting a potential role in neurodegenerative conditions affecting cognition, such as Alzheimer's disease (AD). This study aims to investigate neuropathology and AD-related molecular changes within the neocerebellum using post-mortem human brain tissue microarrays (TMAs). Immunohistochemistry was conducted on neocerebellar paraffin-embedded TMAs from 24 AD and 24 matched control cases, and free-floating neocerebellar sections from 6 AD and 6 controls. Immunoreactivity was compared between control and AD groups for neuropathological hallmarks (amyloid-β, tau, ubiquitin), Purkinje cells (calbindin), microglia (IBA1, HLA-DR), astrocytes (GFAP) basement-membrane associated molecules (fibronectin, collagen IV), endothelial cells (CD31/PECAM-1) and mural cells (PDGFRβ, αSMA). Amyloid-β expression (total immunolabel intensity) and load (area of immunolabel) was increased by >4-fold within the AD cerebellum. Purkinje cell counts, ubiquitin and tau immunoreactivity were unchanged in AD. IBA1 expression and load was increased by 91% and 69%, respectively, in AD, with no change in IBA1-positive cell number. IBA1-positive cell process length and branching was reduced by 22% and 41%, respectively, in AD. HLA-DR and GFAP immunoreactivity was unchanged in AD. HLA-DR-positive cell process length and branching was reduced by 33% and 49%, respectively, in AD. Fibronectin expression was increased by 27% in AD. Collagen IV, PDGFRβ and αSMA immunoreactivity was unchanged in AD. The number of CD31-positive vessels was increased by 98% in AD, suggesting the increase in CD31 expression and load in AD is due to greater vessel number. The PDGFRβ/CD31 load ratio was reduced by 59% in AD. These findings provide evidence of molecular changes affecting microglia and the neurovasculature within the AD neocerebellum. These changes, occurring without overt neuropathology, support the hypothesis of microglial and neurovascular dysfunction as drivers of AD, which has implications on the neocerebellar contribution to AD symptomatology and pathophysiology.
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Woelfel JR, Dudley-Javoroski S, Shields RK. Precision Physical Therapy: Exercise, the Epigenome, and the Heritability of Environmentally Modified Traits. Phys Ther 2018; 98:946-952. [PMID: 30388254 PMCID: PMC6185994 DOI: 10.1093/ptj/pzy092] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/01/2018] [Accepted: 06/12/2018] [Indexed: 12/14/2022]
Abstract
One of the newest frontiers of physical therapy is the field of epigenetics, which examines how pervasive environmental factors such as exercise regulate the expression of genes. The epigenome may be one of the most powerful systems through which exercise exerts its beneficial effects on health and longevity. Large epidemiology studies show that individuals who regularly exercise demonstrate a lower "epigenetic age," experience fewer metabolic diseases, and enjoy greater longevity. However, the dose, mode, intensity, and duration of exercise required to achieve a healthy epigenetic profile is unknown. As experts in exercise prescription, physical therapists are ideally suited to contribute to the discovery of this dose-response relationship. This perspective makes a case for the genesis of "precision physical therapy," which capitalizes on epigenetic discoveries to optimize exercise-based interventions. Summarized here is the emerging body of knowledge supporting epigenetic adaptations to exercise in humans, including the intriguing possibility that these environmentally modified traits could be passed down to offspring. In the future, it is likely that epigenetic data will enhance our understanding of individual disease risk and individual response to prescribed exercise. The profession of physical therapy must be alert to new epigenetic knowledge that can enhance the specificity and efficacy of movement-based treatments.
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Affiliation(s)
- Jessica R Woelfel
- Department of Emergency Medicine, Carver College of Medicine, University of Iowa, Iowa City, Iowa
| | - Shauna Dudley-Javoroski
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, University of Iowa
| | - Richard K Shields
- Department of Physical Therapy and Rehabilitation Science, Carver College of Medicine, 1–252 Medical Education Building, University of Iowa, Iowa City, IA 52252 (USA),Address all correspondence to Dr Shields at:
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Teijido O, Cacabelos R. Pharmacoepigenomic Interventions as Novel Potential Treatments for Alzheimer's and Parkinson's Diseases. Int J Mol Sci 2018; 19:E3199. [PMID: 30332838 PMCID: PMC6213964 DOI: 10.3390/ijms19103199] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Revised: 10/05/2018] [Accepted: 10/08/2018] [Indexed: 12/22/2022] Open
Abstract
Cerebrovascular and neurodegenerative disorders affect one billion people around the world and result from a combination of genomic, epigenomic, metabolic, and environmental factors. Diagnosis at late stages of disease progression, limited knowledge of gene biomarkers and molecular mechanisms of the pathology, and conventional compounds based on symptomatic rather than mechanistic features, determine the lack of success of current treatments, including current FDA-approved conventional drugs. The epigenetic approach opens new avenues for the detection of early presymptomatic pathological events that would allow the implementation of novel strategies in order to stop or delay the pathological process. The reversibility and potential restoring of epigenetic aberrations along with their potential use as targets for pharmacological and dietary interventions sited the use of epidrugs as potential novel candidates for successful treatments of multifactorial disorders involving neurodegeneration. This manuscript includes a description of the most relevant epigenetic mechanisms involved in the most prevalent neurodegenerative disorders worldwide, as well as the main potential epigenetic-based compounds under investigation for treatment of those disorders and their limitations.
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Affiliation(s)
- Oscar Teijido
- EuroEspes Biomedical Research Center, Institute of Medical Science and Genomic Medicine, 15165 La Coruña, Spain.
| | - Ramón Cacabelos
- EuroEspes Biomedical Research Center, Institute of Medical Science and Genomic Medicine, 15165 La Coruña, Spain.
- Chair of Genomic Medicine, Continental University Medical School, Huancayo 12000, Peru.
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7
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Eom J, Feisst V, Ranjard L, Loomes K, Damani T, Jackson-Patel V, Locke M, Sheppard H, Narayan P, Dunbar PR. Visualization and Quantification of Mesenchymal Cell Adipogenic Differentiation Potential with a Lineage Specific Marker. J Vis Exp 2018. [PMID: 29658914 PMCID: PMC5933300 DOI: 10.3791/57153] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
Several dyes are currently available for use in detecting differentiation of mesenchymal cells into adipocytes. Dyes, such as Oil Red O, are cheap, easy to use and widely utilized by laboratories analyzing the adipogenic potential of mesenchymal cells. However, they are not specific to changes in gene transcription. We have developed a gene-specific differentiation assay to analyze when a mesenchymal cell has switched its fate to an adipogenic lineage. Immuno-labelling against fatty acid binding protein-4 (FABP4), a lineage-specific marker of adipogenic differentiation, enabled visualization and quantification of differentiated cells. The ability to quantify adipogenic differentiation potential of mesenchymal cells in a 96 well microplate format has promising implications for a number of applications. Hundreds of clinical trials involve the use of adult mesenchymal stromal cells and it is currently difficult to correlate therapeutic outcomes within and especially between such clinical trials. This simple high-throughput FABP4 assay provides a quantitative assay for assessing the differentiation potential of patient-derived cells and is a robust tool for comparing different isolation and expansion methods. This is particularly important given the increasing recognition of the heterogeneity of the cells being administered to patients in mesenchymal cell products. The assay also has potential utility in high throughput drug screening, particularly in obesity and pre-diabetes research.
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Affiliation(s)
- Jennifer Eom
- School of Biological Sciences, The University of Auckland
| | - Vaughan Feisst
- School of Biological Sciences, The University of Auckland
| | - Louis Ranjard
- Research School of Biology, The Australian National University
| | - Kerry Loomes
- School of Biological Sciences, The University of Auckland
| | - Tanvi Damani
- School of Biological Sciences, The University of Auckland
| | - Victoria Jackson-Patel
- School of Biological Sciences, The University of Auckland; Auckland Cancer Society Research Centre, Faculty of Medical and Health Sciences, The University of Auckland
| | - Michelle Locke
- Department of Plastic Surgery, Counties Manukau District Health Board; Department of Surgery, Faculty of Medical and Health Sciences, The University of Auckland
| | | | - Pritika Narayan
- School of Biological Sciences, The University of Auckland; Biomedical Imaging Research Unit, Faculty of Medical and Health Sciences, The University of Auckland;
| | - P Rod Dunbar
- School of Biological Sciences, The University of Auckland; Maurice Wilkins Centre, The University of Auckland
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8
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Murray HC, Low VF, Swanson ME, Dieriks BV, Turner C, Faull RL, Curtis MA. Distribution of PSA-NCAM in normal, Alzheimer’s and Parkinson’s disease human brain. Neuroscience 2016; 330:359-75. [DOI: 10.1016/j.neuroscience.2016.06.003] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/31/2016] [Revised: 06/01/2016] [Accepted: 06/02/2016] [Indexed: 12/25/2022]
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9
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Bennett NK, Dhaliwal A, Moghe PV. Convergence of Highly Resolved and Rapid Screening Platforms with Dynamically Engineered, Cell Phenotype-Prescriptive Biomaterials. ACTA ACUST UNITED AC 2016; 2:142-151. [PMID: 27482508 DOI: 10.1007/s40495-016-0057-y] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/01/2022]
Abstract
Biophysical and biochemical cues from the cellular microenvironment initiate intracellular signaling through cellular membrane receptors and trigger specific cell developmental programs. Extracellular substrates and matrix scaffolds engineered to mimic cell's native physiological environment must incorporate the multifactorial parameters (composition, micro and nanoscale organization and topography) of the extracellular matrix as well as the dynamic nature of the matrix. The design of such engineered biomaterials is challenged by the inherent complexity and dynamic nature of the cell-extracellular matrix reciprocity, while the validation of robust microenvironments requires a deeper, higher content phenotypic resolution of cell-matrix interactions alongside a rapid screening capability. To this end, high-throughput platforms are integral to facilitating the screening and optimization of complex engineered microenvironments for directing desired cell developmental pathway. This review highlights the recent advances in biomaterial platforms that present dynamic cues and enable high throughput screening of cell's response to a combination of micro-environmental factors. We also address some newer techniques involving high content image informatics to elucidate emergent cellular behaviors with a focus on stem cell regenerative endpoints.
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Affiliation(s)
- Neal K Bennett
- Department of Biomedical Engineering, Rutgers University, Piscataway, NJ
| | - Anandika Dhaliwal
- Department of Biomedical Engineering, Rutgers University, Piscataway, NJ
| | - Prabhas V Moghe
- Department of Biomedical Engineering, Rutgers University, Piscataway, NJ; Department of Chemical and Biochemical Engineering, Rutgers University, Piscataway, NJ
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10
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Narayan PJ, Kim SL, Lill C, Feng S, Faull RLM, Curtis MA, Dragunow M. Assessing fibrinogen extravasation into Alzheimer's disease brain using high-content screening of brain tissue microarrays. J Neurosci Methods 2015; 247:41-9. [PMID: 25813427 DOI: 10.1016/j.jneumeth.2015.03.017] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2015] [Revised: 03/10/2015] [Accepted: 03/12/2015] [Indexed: 12/21/2022]
Abstract
BACKGROUND Tissue microarrays are commonly used to evaluate disease pathology however methods to automate and quantify pathological changes are limited. NEW METHOD This article demonstrates the utility of the VSlide scanner (MetaSystems) for automated image acquisition from immunolabelled tissue microarray slides, and subsequent automated image analysis with MetaXpress (Molecular Devices) software to obtain objective, efficient and reproducible data from immunolabelled tissue microarray sections. RESULTS Significant increases in fibrinogen immunolabelling were observed in 29 Alzheimer's disease cases compared to 28 control cases analysed from a single tissue microarray slide. Western blot analysis also demonstrated significant increases in fibrinogen immunolabelling in 6 Alzheimer's cases compared to 6 control cases. The observed changes were also validated with gold standard blinded manual H-scoring. COMPARISON WITH EXISTING METHOD VSlide Metafer software offers a 'tissue microarray acquisition' plugin for easy mapping of tissue cores with their original position on the tissue microarray map. High resolution VSlide images are compatible with MetaXpress image analysis software. This article details the coupling of these two technologies to accurately and reproducibly analyse immunolabelled tissue microarrays within minutes, compared to the gold standard method of manual counting using H-scores which is significantly slower and prone to inter-observer variation. CONCLUSIONS Here, we couple brain tissue microarray technology with high-content screening and automated image analysis as a powerful way to address bottle necks in data generation and improve throughput, as well as sensitivity to study biological/pathological changes in brain disease.
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Affiliation(s)
- Pritika J Narayan
- Gravida, National Centre for Growth and Development, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Biomedical Imaging Research Unit, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Sue-Ling Kim
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Claire Lill
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Sheryl Feng
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Richard L M Faull
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Maurice A Curtis
- Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand
| | - Michael Dragunow
- Gravida, National Centre for Growth and Development, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand; Centre for Brain Research, Faculty of Medical and Health Sciences, The University of Auckland, Private Bag 92019, Auckland, New Zealand.
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11
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Increased acetyl and total histone levels in post-mortem Alzheimer's disease brain. Neurobiol Dis 2015; 74:281-94. [DOI: 10.1016/j.nbd.2014.11.023] [Citation(s) in RCA: 84] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2014] [Revised: 11/20/2014] [Accepted: 11/26/2014] [Indexed: 11/19/2022] Open
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12
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Lin XP, Feng L, Xie CG, Chen DB, Pei Z, Liang XL, Xie QY, Li XH, Pan SY. Valproic acid attenuates the suppression of acetyl histone H3 and CREB activity in an inducible cell model of Machado-Joseph disease. Int J Dev Neurosci 2014; 38:17-22. [PMID: 25068645 DOI: 10.1016/j.ijdevneu.2014.07.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2014] [Revised: 07/15/2014] [Accepted: 07/16/2014] [Indexed: 11/26/2022] Open
Abstract
Machado-Joseph disease (MJD) is caused by a (CAG)n trinucleotide repeat expansion that is translated into an abnormally long polyglutamine tract. This disease is considered the most common form of spinocerebellar ataxia (SCA). In the present study, we developed stable inducible cell lines (PC12Tet-On-Ataxin-3-Q28/84) expressing ataxin-3 with either normal or abnormal CAG repeats under doxycycline control. The expression of acetyl histone H3 and the induction of c-Fos in response to cAMP were strongly suppressed in cells expressing the protein with the expanded polyglutamine tract. Treatment with valproic acid, a histone deacetylase inhibitor (HDACi), attenuated mutant ataxin-3-induced cell toxicity and suppression of acetyl histone H3, phosphorylated cAMP-responsive element binding protein (p-CREB) as well as c-Fos expression. These results indicate that VPA can stimulate the up-regulation of gene transcription through hyperacetylation. Thus, VPA might have a therapeutic effect on MJD.
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Affiliation(s)
- X P Lin
- Department of Huiqiao Building, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
| | - L Feng
- Department of Neurological Intensive Care Unit, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - C G Xie
- Department of Neurology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - D B Chen
- Department of Neurology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Z Pei
- Department of Neurology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - X L Liang
- Department of Neurology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China
| | - Q Y Xie
- Department of Hyperbaric Oxygen Therapy, Guangzhou General Hospital of Guangzhou Military Area Command of Chinese PLA, Guangzhou, Guangdong Province, China
| | - X H Li
- Department of Neurology, First Affiliated Hospital, Sun Yat-sen University, Guangzhou, Guangdong Province, China.
| | - S Y Pan
- Department of Neurology, Nanfang Hospital, Southern Medical University, Guangzhou, Guangdong Province, China
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Chang FM, Ou TY, Cheng WN, Chou ML, Lee KC, Chin YP, Lin CP, Chang KD, Lin CT, Su CH. Short-term exposure to fluconazole induces chromosome loss in Candida albicans: an approach to produce haploid cells. Fungal Genet Biol 2014; 70:68-76. [PMID: 25038494 DOI: 10.1016/j.fgb.2014.06.009] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2014] [Revised: 06/16/2014] [Accepted: 06/19/2014] [Indexed: 02/07/2023]
Abstract
Candida albicans is considered to be an obligate diploid fungus. Here, we describe an approach to isolate aneuploids or haploids induced by the short-term (12-16 h) exposure of diploid reference strains SC5314 and CAI4 to the most commonly used antifungal drug, fluconazole, followed by repeated single-cell separation among small morphologically distinct colonies in the inhibition zone. The isolated strains had altered cell morphology and LOH events in the MTL and other marker alleles of the analyzed loci at 8 chromosomes of C. albicans with decreased DNA content. The present study employed next-generation sequencing (NGS) combined flow cytometry analysis of the DNA content to analyze the haploid, autodiploid, and aneuploid strains that arose from the fluconazole treatment instead of using the conventional single nucleotide polymorphism/comparative genome hybridization (SNP/CGH) method. A multiple-alignment tool was also developed based on sequenced data from NGS to establish haplotype mapping for each chromosome of the selected strains. These findings revealed that C. albicans experiences 'concerted chromosome loss' to form strains with homozygous alleles and that it even has a haploid status after short-term exposure to fluconazole. Additionally, we developed a new platform to analyze chromosome copy number using NGS.
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Affiliation(s)
- Fang-Mo Chang
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - Tsong-Yih Ou
- Division of Infectious Disease, Department of Internal Medicine, Wan Fang Hospital, Taipei Medical University, Taipei, Taiwan
| | - Wei-Ning Cheng
- Department of Microbiology and Immunology, Taipei Medical University, Taipei, Taiwan
| | - Ming-Li Chou
- Department of Microbiology and Immunology, Taipei Medical University, Taipei, Taiwan
| | - Kai-Cheng Lee
- Department of Microbiology and Immunology, Taipei Medical University, Taipei, Taiwan
| | - Yi-Ping Chin
- Department of Microbiology and Immunology, Taipei Medical University, Taipei, Taiwan
| | | | | | - Che-Tong Lin
- School of Dentistry, College of Oral Medicine, Taipei Medical University, Taipei, Taiwan
| | - Ching-Hua Su
- Department of Microbiology and Immunology, Taipei Medical University, Taipei, Taiwan.
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14
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Coppieters N, Dieriks BV, Lill C, Faull RLM, Curtis MA, Dragunow M. Global changes in DNA methylation and hydroxymethylation in Alzheimer's disease human brain. Neurobiol Aging 2013; 35:1334-44. [PMID: 24387984 DOI: 10.1016/j.neurobiolaging.2013.11.031] [Citation(s) in RCA: 235] [Impact Index Per Article: 21.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2013] [Revised: 11/25/2013] [Accepted: 11/29/2013] [Indexed: 11/17/2022]
Abstract
DNA methylation (5-methylcytosine [5mC]) is one of several epigenetic markers altered in Alzheimer's disease (AD) brain. More recently, attention has been given to DNA hydroxymethylation (5-hydroxymethylcytosine [5hmC]), the oxidized form of 5mC. Whereas 5mC is generally associated with the inhibition of gene expression, 5hmC has been associated with increased gene expression and is involved in cellular processes such as differentiation, development, and aging. Recent findings point toward a role for 5hmC in the development of diseases including AD, potentially opening new pathways for treating AD through correcting methylation and hydroxymethylation alterations. In the present study, levels of 5mC and 5hmC were investigated in the human middle frontal gyrus (MFG) and middle temporal gyrus (MTG) by immunohistochemistry. Immunoreactivity for 5mC and 5hmC were significantly increased in AD MFG (N = 13) and MTG (N = 29) compared with age-matched controls (MFG, N = 13 and MTG, N = 29). Global levels of 5mC and 5hmC positively correlated with each other and with markers of AD including amyloid beta, tau, and ubiquitin loads. Our results showed a global hypermethylation in the AD brain and revealed that levels of 5hmC were also significantly increased in AD MFG and MTG with no apparent influence of gender, age, postmortem delay, or tissue storage time. Using double-fluorescent immunolabeling, we found that in control and AD brains, levels of 5mC and 5hmC were low in astrocytes and microglia but were elevated in neurons. In addition, our colocalization study showed that within the same nuclei, 5mC and 5hmC mostly do not coexist. The present study clearly demonstrates the involvement of 5mC and 5hmC in AD emphasizing the need for future studies determining the exact time frame of these epigenetic changes during the progression of AD pathology.
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Affiliation(s)
- Natacha Coppieters
- Departments of Pharmacology and Clinical Pharmacology, The University of Auckland, Auckland, New Zealand; Gravida National Centre for Growth and Development, The University of Auckland, Auckland, New Zealand; Centre for Brain Research, The University of Auckland, Auckland, New Zealand
| | - Birger V Dieriks
- Centre for Brain Research, The University of Auckland, Auckland, New Zealand; Department of Anatomy with Radiology, The University of Auckland, Auckland, New Zealand
| | - Claire Lill
- Centre for Brain Research, The University of Auckland, Auckland, New Zealand; Department of Anatomy with Radiology, The University of Auckland, Auckland, New Zealand
| | - Richard L M Faull
- Centre for Brain Research, The University of Auckland, Auckland, New Zealand; Department of Anatomy with Radiology, The University of Auckland, Auckland, New Zealand
| | - Maurice A Curtis
- Centre for Brain Research, The University of Auckland, Auckland, New Zealand; Department of Anatomy with Radiology, The University of Auckland, Auckland, New Zealand
| | - Mike Dragunow
- Departments of Pharmacology and Clinical Pharmacology, The University of Auckland, Auckland, New Zealand; Gravida National Centre for Growth and Development, The University of Auckland, Auckland, New Zealand; Centre for Brain Research, The University of Auckland, Auckland, New Zealand.
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15
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Hasan A, Mitchell A, Schneider A, Halene T, Akbarian S. Epigenetic dysregulation in schizophrenia: molecular and clinical aspects of histone deacetylase inhibitors. Eur Arch Psychiatry Clin Neurosci 2013; 263:273-84. [PMID: 23381549 DOI: 10.1007/s00406-013-0395-2] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/15/2012] [Accepted: 01/18/2013] [Indexed: 12/22/2022]
Abstract
Notwithstanding the considerable advances in the treatment options for schizophrenia, the cognitive symptoms in particular are not receptive to antipsychotic treatment and considered one of the main predictors for poor social and functional outcome of the disease. Recent findings in preclinical model systems indicate that epigenetic modulation might emerge as a promising target for the treatment of cognitive disorders. The aim of this review is to introduce some of the principles of chromatin biology to the reader and to discuss a possible role in the neurobiology and pathophysiology of schizophrenia. We will discuss potential epigenetic targets for drug therapy, including histone deacetylase inhibitors (HDACi). In a second part, conceptual and practical challenges associated with clinical trials of chromatin-modifying drugs in psychiatric patient populations are discussed, including safety profiles, the potential for adverse effects and general issues revolving around pharmacokinetics and pharmacodynamics. Additional investigations are required in order to fully evaluate the potential of HDACi and similar "epigenetic therapies" as novel treatment options for schizophrenia and other psychotic disease.
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Affiliation(s)
- Alkomiet Hasan
- Deparment of Psychiatry and Psychotherapy, Ludwig-Maximilians-University, Nussbaumstr. 7, 80336 Munich, Germany.
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16
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Kasprzyk L, Defossez PA, Miotto B. [Epigenetic regulation in neuronal differentiation and brain function]. Biol Aujourdhui 2013; 207:1-17. [PMID: 23694721 DOI: 10.1051/jbio/2013001] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2012] [Indexed: 11/15/2022]
Abstract
DNA methylation compacts chromatin structure and represses gene transcription. It is important for numerous cellular processes, including embryonic development, X-chromosome inactivation, suppression of transposable elements, and cellular differentiation. In addition, environmental cues, including drugs, pollutants, trauma or early-life social environment, alter DNA methylation patterns in different organs. For instance, studies have unravelled a complex and dynamic interplay between environment, DNA methylation and neuron function during development and in the adult. This crosstalk is hypothesized as an essential molecular event underlying the effects of long-term memory, drug addiction, and several psychotic and behavioural disorders. In this review, we give a summary of this exciting field of research and highlight the molecular functions of DNA methylation and of proteins interacting with methylated DNA.
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Affiliation(s)
- Laetitia Kasprzyk
- Unité d'Épigénétique et Destin Cellulaire, CNRS UMR7216, Université Paris Diderot 35, rue Hélène Brion, 75205 Paris Cedex 13, France
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17
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Xu Z, Li H, Jin P. Epigenetics-Based Therapeutics for Neurodegenerative Disorders. CURRENT GERIATRICS REPORTS 2012; 1:229-236. [PMID: 23526405 DOI: 10.1007/s13670-012-0027-0] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
Epigenetic regulation, such as DNA methylation and histone modification, is implicated in the aberrant changes in gene expression that occur during the progression of neurodegeneration. Many epigenetics-based drugs have been developed recently for the treatment of some neurodegenerative disorders, including Alzheimer's, Parkinson's, and Huntington's diseases. Here we review recent studies that highlight the role of epigenetic modifications in neurodegeneration, among them DNA methylation and demethylation and histone acetylation and deacetylation; we also explore the possibility of using epigenetics-based therapeutics to treat neurodegenerative disorders.
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Affiliation(s)
- Zihui Xu
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA 30322, USA ; Division of Histology and Embryology, Department of Anatomy, Tongji Medical College, Huazhong University of Science and Technology, P. R. China
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18
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Abstract
Despite decades of research in the field of Alzheimer's disease (AD), a real understanding of its molecular pathophysiology and treatments relevant to the day-to-day lives of patients remain out of reach. Research has, with good reason, focused on certain key pathways and potential mechanisms, but sometimes this has been at the expense of work on other theories, which may be slowing down progress in this field. Interesting theories at present include oxidative stress and caloric restriction. Work on the Aβ cascade should continue but with a shift in focus to its intracellular effects and an awareness that additional pathogenetic factors and processes must be involved--most importantly, brain aging. Hyperphosphorylation of tau, for instance, provides another interesting pathway, with one old drug showing promise in this regard. Moreover, work in epigenetics and on protein homeostasis has produced interesting findings and both lines of investigation may reveal suitable targets for future intervention. Taken together, analysis of the biochemistry of aged neurons and the interplay with pathways of neurodegeneration may lead to a better understanding of AD and how to treat and prevent this condition.
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19
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Samaroo HD, Opsahl AC, Schreiber J, O'Neill SM, Marconi M, Qian J, Carvajal-Gonzalez S, Tate B, Milici AJ, Bales KR, Stephenson DT. High throughput object-based image analysis of β-amyloid plaques in human and transgenic mouse brain. J Neurosci Methods 2011; 204:179-188. [PMID: 22019329 DOI: 10.1016/j.jneumeth.2011.10.003] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/29/2011] [Revised: 10/05/2011] [Accepted: 10/07/2011] [Indexed: 01/30/2023]
Abstract
Advances in imaging technology have enabled automated approaches for quantitative image analysis. In this study, a high content object based image analysis method was developed for quantification of β-amyloid (Aβ) plaques in postmortem brains of Alzheimer's disease (AD) subjects and in transgenic mice over overexpressing Aβ. Digital images acquired from immunohistochemically stained sections of the superior frontal gyrus were analyzed for Aβ plaque burden using a Definiens object-based segmentation approach. Blinded evaluation of Aβ stained sections from AD and aged matched human subjects accurately identified AD cases with one exception. Brains from transgenic mice overexpressing Aβ (PS1APP mice) were also evaluated by our Definiens object based image analysis approach. We observed an age-dependent increase in the amount of Aβ plaque load that we quantified in both the hippocampus and cortex. From the contralateral hemisphere, we measured the amount of Aβ in brain homogenates biochemically and observed a significant correlation between our biochemical measurements and those that we measured by our object based Definiens system in the hippocampus. Assessment of Aβ plaque load in PS1APP mice using a manual segmentation technique (Image-Pro Plus) confirmed the results of our object-based image analysis approach. Image acquisition and analysis of 32 stained human slides and 100 mouse slides were executed in 8 h and 22 h, respectively supporting the relatively high throughput features of the Definiens platform. The data show that digital imaging combined with object based image analysis is a reliable and efficient approach to quantifying Aβ plaques in human and mouse brain.
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Affiliation(s)
- Harry D Samaroo
- Neuroscience Biology, Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA
| | - Alan C Opsahl
- Investigative Pathology, Pfizer Global Research & Development, USA
| | - Jan Schreiber
- Definiens AG, Trappentreustrasse 1, 80339 München, Germany
| | - Sharon M O'Neill
- Neuroscience Biology, Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA
| | - Michael Marconi
- Neuroscience Biology, Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA
| | - Jessie Qian
- Investigative Pathology, Pfizer Global Research & Development, USA
| | - Santos Carvajal-Gonzalez
- Neuroscience Biology, Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA
| | - Barbara Tate
- Neuroscience Biology, Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA
| | - Anthony J Milici
- Neuroscience Biology, Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA
| | - Kelly R Bales
- Neuroscience Biology, Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA.
| | - Diane T Stephenson
- Neuroscience Biology, Pfizer Global Research & Development, Eastern Point Road, Groton, CT 06340, USA
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