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Maiese K. Nicotinamide as a Foundation for Treating Neurodegenerative Disease and Metabolic Disorders. Curr Neurovasc Res 2021; 18:134-149. [PMID: 33397266 PMCID: PMC8254823 DOI: 10.2174/1567202617999210104220334] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2020] [Revised: 12/18/2020] [Accepted: 12/22/2020] [Indexed: 02/06/2023]
Abstract
Neurodegenerative disorders impact more than one billion individuals worldwide and are intimately tied to metabolic disease that can affect another nine hundred individuals throughout the globe. Nicotinamide is a critical agent that may offer fruitful prospects for neurodegenerative diseases and metabolic disorders, such as diabetes mellitus. Nicotinamide protects against multiple toxic environments that include reactive oxygen species exposure, anoxia, excitotoxicity, ethanolinduced neuronal injury, amyloid (Aß) toxicity, age-related vascular disease, mitochondrial dysfunction, insulin resistance, excess lactate production, and loss of glucose homeostasis with pancreatic β-cell dysfunction. However, nicotinamide offers cellular protection in a specific concentration range, with dosing outside of this range leading to detrimental effects. The underlying biological pathways of nicotinamide that involve the silent mating type information regulation 2 homolog 1 (Saccharomyces cerevisiae) (SIRT1), the mechanistic target of rapamycin (mTOR), AMP activated protein kinase (AMPK), and mammalian forkhead transcription factors (FoxOs) may offer insight for the clinical translation of nicotinamide into a safe and efficacious therapy through the modulation of oxidative stress, apoptosis, and autophagy. Nicotinamide is a highly promising target for the development of innovative strategies for neurodegenerative disorders and metabolic disease, but the benefits of this foundation depend greatly on gaining a further understanding of nicotinamide's complex biology.
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Affiliation(s)
- Kenneth Maiese
- Cellular and Molecular Signaling, New York, New York 10022
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2
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Kadam A, Jubin T, Roychowdhury R, Begum R. Role of PARP-1 in mitochondrial homeostasis. Biochim Biophys Acta Gen Subj 2020; 1864:129669. [PMID: 32553688 DOI: 10.1016/j.bbagen.2020.129669] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2020] [Revised: 06/04/2020] [Accepted: 06/09/2020] [Indexed: 12/11/2022]
Abstract
BACKGROUND Nuclear poly(ADP-ribose) polymerase-1 (PARP-1) is a well characterised protein that accounts for the majority of PARylation reactions using NAD+ as a substrate, regulating diverse cellular functions. In addition to its nuclear functions, several recent studies have identified localization of PARP-1 in mitochondria and emphasized its possible role in maintaining mitochondrial homeostasis. Various reports suggest that nuclear PARP-1 has been implicated in diverse mitochondria-specific communication processes. SCOPE OF REVIEW The present review emphasizes on the potential role of PARP-1 in mitochondrial processes such as bioenergetics, mtDNA maintenance, cell death and mitophagy. MAJOR CONCLUSIONS The origin of mitochondrial PARP-1 is still an enigma; however researchers are trying to establish the cross-talk between nuclear and mitochondrial PARP-1 and how these PARP-1 pools modulate mitochondrial activity. GENERAL SIGNIFICANCE A better understanding of the possible role of PARP-1 in mitochondrial homeostasis helps us to explore the potential therapeutic targets to protect mitochondrial dysfunctions.
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Affiliation(s)
- Ashlesha Kadam
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat, India
| | - Tina Jubin
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat, India
| | - Rittwika Roychowdhury
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat, India
| | - Rasheedunnisa Begum
- Department of Biochemistry, Faculty of Science, The Maharaja Sayajirao University of Baroda, Vadodara 390002, Gujarat, India.
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Abstract
PURPOSE Radiotherapy (RT) is a mainstay in the treatment of solid tumors and works by inducing free radical stress in tumor cells, leading to loss of reproductive integrity. The optimal treatment strategy has to consider damage to both tumor and normal cells and is determined by five factors known as the 5 R's of radiobiology: Reoxygenation, DNA repair, radiosensitivity, redistribution in the cell cycle and repopulation. The aim of this review is (i) to present evidence that these 5 R's are strongly influenced by cellular and whole-body metabolism that in turn can be modified through ketogenic therapy in form of ketogenic diets and short-term fasting and (ii) to stimulate new research into this field including some research questions deserving further study. CONCLUSIONS Preclinical and some preliminary clinical data support the hypothesis that ketogenic therapy could be utilized as a complementary treatment in order to improve the outcome after RT, both in terms of higher tumor control and in terms of lower normal tissue complication probability. The first effect relates to the metabolic shift from glycolysis toward mitochondrial metabolism that selectively increases ROS production and impairs ATP production in tumor cells. The second effect is based on the differential stress resistance phenomenon, which is achieved when glucose and growth factors are reduced and ketone bodies are elevated, reprogramming normal but not tumor cells from proliferation toward maintenance and stress resistance. Underlying both effects are metabolic differences between normal and tumor cells that ketogenic therapy seeks to exploit. Specifically, the recently discovered role of the ketone body β-hydroxybutyrate as an endogenous class-I histone deacetylase inhibitor suggests a dual role as a radioprotector of normal cells and a radiosensitzer of tumor cells that opens up exciting possibilities to employ ketogenic therapy as a cost-effective adjunct to radiotherapy against cancer.
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Affiliation(s)
- Rainer J Klement
- a Department of Radiotherapy and Radiation Oncology , Leopoldina Hospital , Schweinfurt , Germany
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4
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Weidele K, Beneke S, Bürkle A. The NAD + precursor nicotinic acid improves genomic integrity in human peripheral blood mononuclear cells after X-irradiation. DNA Repair (Amst) 2017; 52:12-23. [PMID: 28216063 DOI: 10.1016/j.dnarep.2017.02.001] [Citation(s) in RCA: 20] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2016] [Revised: 02/02/2017] [Accepted: 02/02/2017] [Indexed: 01/07/2023]
Abstract
NAD+ is an essential cofactor for enzymes catalyzing redox-reactions as well as an electron carrier in energy metabolism. Aside from this, NAD+ consuming enzymes like poly(ADP-ribose) polymerases and sirtuins are important regulators involved in chromatin-restructuring processes during repair and epigenetics/transcriptional adaption. In order to replenish cellular NAD+ levels after cleavage, synthesis starts from precursors such as nicotinamide, nicotinamide riboside or nicotinic acid to match the need for this essential molecule. In the present study, we investigated the impact of supplementation with nicotinic acid on resting and proliferating human mononuclear blood cells with a focus on DNA damage and repair processes. We observed that nicotinic acid supplementation increased NAD+ levels as well as DNA repair efficiency and enhanced genomic stability evaluated by micronucleus test after x-ray treatment. Interestingly, resting cells displayed lower basal levels of DNA breaks compared to proliferating cells, but break-induction rates were identical. Despite similar levels of p53 protein upregulation after irradiation, higher NAD+ concentrations led to reduced acetylation of this protein, suggesting enhanced SIRT1 activity. Our data reveal that even in normal primary human cells cellular NAD+ levels may be limiting under conditions of genotoxic stress and that boosting the NAD+ system with nicotinic acid can improve genomic stability.
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Affiliation(s)
- Kathrin Weidele
- Molecular Toxicology Group, Department of Biology, University of Konstanz, Universitaetsstr. 10, 78457 Konstanz, Germany.
| | - Sascha Beneke
- Molecular Toxicology Group, Department of Biology, University of Konstanz, Universitaetsstr. 10, 78457 Konstanz, Germany.
| | - Alexander Bürkle
- Molecular Toxicology Group, Department of Biology, University of Konstanz, Universitaetsstr. 10, 78457 Konstanz, Germany.
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5
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Wang Y, Luo J. Acetylation of BLM protein regulates its function in response to DNA damage. RSC Adv 2017. [DOI: 10.1039/c7ra06666j] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
This study first revealed the acetylation of the BLM protein and studied this regulatory process in the DNA damage response.
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Affiliation(s)
- Yankun Wang
- Department of Medical Genetics
- Peking University Health Science Center
- Beijing
- China
| | - Jianyuan Luo
- Department of Medical Genetics
- Peking University Health Science Center
- Beijing
- China
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6
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Lin CC, Liaw SF, Chiu CH, Chen WJ, Lin MW, Chang FT. Effects of nasal CPAP on exhaled SIRT1 and tumor necrosis factor-α in patients with obstructive sleep apnea. Respir Physiol Neurobiol 2016; 228:39-46. [DOI: 10.1016/j.resp.2016.03.001] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2015] [Revised: 02/06/2016] [Accepted: 03/01/2016] [Indexed: 10/22/2022]
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Martin A, Tegla CA, Cudrici CD, Kruszewski AM, Azimzadeh P, Boodhoo D, Mekala AP, Rus V, Rus H. Role of SIRT1 in autoimmune demyelination and neurodegeneration. Immunol Res 2015; 61:187-97. [PMID: 25281273 DOI: 10.1007/s12026-014-8557-5] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Multiple sclerosis (MS) is a demyelinating disease characterized by chronic inflammation of the central nervous system, in which many factors can act together to influence disease susceptibility and progression. SIRT1 is a member of the histone deacetylase class III family of proteins and is an NAD(+)-dependent histone and protein deacetylase. SIRT1 can induce chromatin silencing through the deacetylation of histones and plays an important role as a key regulator of a wide variety of cellular and physiological processes including DNA damage, cell survival, metabolism, aging, and neurodegeneration. It has gained a lot of attention recently because many studies in animal models of demyelinating and neurodegenerative diseases have shown that SIRT1 induction can ameliorate the course of the disease. SIRT1 expression was found to be decreased in the peripheral blood mononuclear cells of MS patients during relapses. SIRT1 represents a possible biomarker of relapses and a potential new target for therapeutic intervention in MS. Modulation of SIRT1 may be a valuable strategy for treating or preventing MS and neurodegenerative central nervous system disorders.
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Affiliation(s)
- Alvaro Martin
- Department of Neurology, University of Maryland School of Medicine, Baltimore, MD, 21201, USA
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Chen WJ, Liaw SF, Lin CC, Chiu CH, Lin MW, Chang FT. Effect of Nasal CPAP on SIRT1 and Endothelial Function in Obstructive Sleep Apnea Syndrome. Lung 2015; 193:1037-45. [PMID: 26345325 DOI: 10.1007/s00408-015-9790-y] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2015] [Accepted: 08/19/2015] [Indexed: 10/23/2022]
Abstract
BACKGROUND Sirtuin 1 (SIRT1), a histone/protein deacetylase, has been implicated in aging, metabolism, and stress resistance. SIRT1 regulates endothelial nitric oxide (NO) synthase, restores NO availability, and is involved in different aspects of cardiovascular disease. The aim of this study was to evaluate any abnormalities with regard to SIRT1 protein level in the blood, SIRT1 activity, and impaired endothelial function in patients with obstructive sleep apnea syndrome (OSAS). We also investigated whether or not OSAS patients who received nasal continuous positive airway pressure (CPAP) treatment showed improvements in the levels of SIRT1. METHODS Thirty-five patients with moderately severe to severe OSAS who requested nasal CPAP treatment and 20 healthy controls were prospectively enrolled. The SIRT1 protein levels in blood and its activity, and the serum levels of nitric oxide derivative (NO x ) were assessed. All subjects participated in sleep studies, which were repeated 3 months after nasal CPAP treatment in the patients with OSAS. RESULTS In the patients with OSAS, the level of SIRT1 in the blood, its activity, and that of NO x was lower than those of normal subjects before nasal CPAP treatment. After nasal CPAP treatment, the level of SIRT1 in the blood and its activity increased from 0.55 ± 0.32 pg/μg of total protein and 3085.53 ± 1071.57 arbitrary fluorescence units (AFUs)/μg of total protein to 1.13 ± 0.43 pg/μg of total protein and 5344.65 ± 1579.71 AFUs/μg of total protein. The serum levels of NO x in the patients with OSAS increased from 16.36 ± 5.78 to 25.94 ± 5.17 µM. CONCLUSIONS Successful treatment for OSAS with nasal CPAP can restore blood levels of the SIRT1 protein and its activity and serum levels of NO x .
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Affiliation(s)
- Wei-Ji Chen
- Chest Division, Department of Internal Medicine, Department of Medical Research, Mackay Memorial Hospital, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan, ROC
| | - Shwu-Fang Liaw
- Chest Division, Department of Internal Medicine, Department of Medical Research, Mackay Memorial Hospital, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan, ROC
| | - Ching-Chi Lin
- Division of Pulmonary Medicine, Department of Internal Medicine, Taipei Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, No. 289, Jianguo Rd., Xindian Dist., New Taipei City, 23142, Taiwan, ROC. .,Chest Division, Department of Internal Medicine, Department of Medical Research, Mackay Memorial Hospital, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan, ROC.
| | - Chung-Hsin Chiu
- Chest Division, Department of Internal Medicine, Department of Medical Research, Mackay Memorial Hospital, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan, ROC
| | - Mei-Wei Lin
- Chest Division, Department of Internal Medicine, Department of Medical Research, Mackay Memorial Hospital, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan, ROC
| | - Feng-Ting Chang
- Chest Division, Department of Internal Medicine, Department of Medical Research, Mackay Memorial Hospital, Mackay Junior College of Medicine, Nursing, and Management, Taipei, Taiwan, ROC
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Nair GG, Vincent RK, Odorico JS. Ectopic Ptf1a expression in murine ESCs potentiates endocrine differentiation and models pancreas development in vitro. Stem Cells 2014; 32:1195-207. [PMID: 24375815 DOI: 10.1002/stem.1616] [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: 06/13/2013] [Revised: 10/04/2013] [Accepted: 10/25/2013] [Indexed: 11/09/2022]
Abstract
Besides its role in exocrine differentiation, pancreas-specific transcription factor 1a (PTF1a) is required for pancreas specification from the foregut endoderm and ultimately for endocrine cell formation. Examining the early role of PTF1a in pancreas development has been challenging due to limiting amounts of embryonic tissue material for study. Embryonic stem cells (ESCs) which can be differentiated in vitro, and without limit to the amount of experimental material, can serve as a model system to study these early developmental events. To this end, we derived and characterized a mouse ESC line with tetracycline-inducible expression of PTF1a (tet-Ptf1a mESCs). We found that transient ectopic expression of PTF1a initiated the pancreatic program in differentiating ESCs causing cells to activate PDX1 expression in bud-like structures resembling pancreatic primordia in vivo. These bud-like structures also expressed progenitor markers characteristic of a developing pancreatic epithelium. The epithelium differentiated to generate a wave of NGN3+ endocrine progenitors, and further formed cells of all three pancreatic lineages. Notably, the insulin+ cells in the cultures were monohormonal, and expressed PDX1 and NKX6.1. PTF1a-induced cultures differentiated into significantly more endocrine and exocrine cells and the ratio of endocrine-to-exocrine cell differentiation could be regulated by retinoic acid (RA) and nicotinamide (Nic) signaling. Moreover, induced cultures treated with RA and Nic exhibited a modest glucose response. Thus, this tet-Ptf1a ESC-based in vitro system is a valuable new tool for interrogating the role of PTF1a in pancreas development and in directing differentiation of ESCs to endocrine cells.
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Affiliation(s)
- Gopika G Nair
- Division of Transplantation, Department of Surgery, University of Wisconsin-Madison School of Medicine and Public Health, Madison, Wisconsin, USA
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10
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Lee KT, Kwon H, Lee D, Bahn YS. A Nudix Hydrolase Protein, Ysa1, Regulates Oxidative Stress Response and Antifungal Drug Susceptibility in Cryptococcus neoformans. MYCOBIOLOGY 2014; 42:52-58. [PMID: 24808735 PMCID: PMC4004948 DOI: 10.5941/myco.2014.42.1.52] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/15/2014] [Revised: 02/20/2014] [Accepted: 02/20/2014] [Indexed: 05/30/2023]
Abstract
A nucleoside diphosphate-linked moiety X (Nudix) hydrolase-like gene, YSA1, has been identified as one of the gromwell plant extract-responsive genes in Cryptococcus neoformans. Ysa1 is known to control intracellular concentrations of ADP-ribose or O-acetyl-ADP-ribose, and has diverse biological functions, including the response to oxidative stress in the ascomycete yeast, Saccharomyces cerevisiae. In this study, we characterized the role of YSA1 in the stress response and adaptation of the basidiomycete yeast, C. neoformans. We constructed three independent deletion mutants for YSA1, and analyzed their mutant phenotypes. We found that ysa1 mutants did not show increased sensitivity to reactive oxygen species-producing oxidative damage agents, such as hydrogen peroxide and menadione, but exhibited increased sensitivity to diamide, which is a thiol-specific oxidant. Ysa1 was dispensable for the response to most environmental stresses, such as genotoxic, osmotic, and endoplasmic reticulum stress. In conclusion, modulation of YSA1 may regulate the cellular response and adaptation of C. neoformans to certain oxidative stresses and contribute to the evolution of antifungal drug resistance.
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Affiliation(s)
- Kyung-Tae Lee
- Department of Biotechnology, Center for Fungal Pathogenesis, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Hyojeong Kwon
- Department of Biotechnology, Center for Fungal Pathogenesis, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
| | - Dohyun Lee
- Nutrex Technology Co., Ltd., Seongnam 463-400, Korea
| | - Yong-Sun Bahn
- Department of Biotechnology, Center for Fungal Pathogenesis, College of Life Science and Biotechnology, Yonsei University, Seoul 120-749, Korea
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11
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Luna A, Aladjem MI, Kohn KW. SIRT1/PARP1 crosstalk: connecting DNA damage and metabolism. Genome Integr 2013; 4:6. [PMID: 24360018 PMCID: PMC3898398 DOI: 10.1186/2041-9414-4-6] [Citation(s) in RCA: 60] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2013] [Accepted: 12/02/2013] [Indexed: 12/20/2022] Open
Abstract
An intricate network regulates the activities of SIRT1 and PARP1 proteins and continues to be uncovered. Both SIRT1 and PARP1 share a common co-factor nicotinamide adenine dinucleotide (NAD+) and several common substrates, including regulators of DNA damage response and circadian rhythms. We review this complex network using an interactive Molecular Interaction Map (MIM) to explore the interplay between these two proteins. Here we discuss how NAD + competition and post-transcriptional/translational feedback mechanisms create a regulatory network sensitive to environmental cues, such as genotoxic stress and metabolic states, and examine the role of those interactions in DNA repair and ultimately, cell fate decisions.
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Affiliation(s)
- Augustin Luna
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
- Bioinformatics Program, Boston University, Boston, MA 02215, USA
| | - Mirit I Aladjem
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
| | - Kurt W Kohn
- Laboratory of Molecular Pharmacology, Center for Cancer Research, National Cancer Institute, NIH, Bethesda, MD 20892, USA
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12
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Martínez-Redondo P, Vaquero A. The diversity of histone versus nonhistone sirtuin substrates. Genes Cancer 2013; 4:148-63. [PMID: 24020006 DOI: 10.1177/1947601913483767] [Citation(s) in RCA: 106] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023] Open
Abstract
The members of the Sir2 family, or sirtuins, are major regulators of the response to different types of stress. The members of the family have adapted to increasing complexities throughout evolution and have become diversified by increasing their number, specificity, and localization and acquiring novel functions. Sirtuins have been consistently implicated in the cross-talk between the genomic information and environment from the prokaryotes onward. Evidence suggests that in the transition to eukaryotes, histones became one of the basic and most conserved targets of the family, to the extent that in yeast and mammals, sirtuins were originally described as NAD(+)-dependent histone deacetylases and classified as class III histone deacetylases. A growing number of studies have determined that sirtuins also target a wide range of nonhistone proteins. Many of these targets are also directly or indirectly related to chromatin regulation. The number of targets has grown considerably in the last decade but has provoked an ill-founded discussion that neglects the importance of histones as sirtuin targets. In this review, we summarize our knowledge regarding the range of sirtuin targets described to date and discuss the different functional implications of histone and nonhistone targets throughout evolution.
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Affiliation(s)
- Paloma Martínez-Redondo
- Cancer Epigenetics and Biology Program, Chromatin Biology Laboratory, Institut d'Investigació Biomèdica de Bellvitge, Barcelona, Spain
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13
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Autophagy and genomic integrity. Cell Death Differ 2013; 20:1444-54. [PMID: 23933813 DOI: 10.1038/cdd.2013.103] [Citation(s) in RCA: 130] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2013] [Revised: 06/07/2013] [Accepted: 07/02/2013] [Indexed: 01/25/2023] Open
Abstract
DNA lesions, constantly produced by endogenous and exogenous sources, activate the DNA damage response (DDR), which involves detection, signaling and repair of the damage. Autophagy, a lysosome-dependent degradation pathway that is activated by stressful situations such as starvation and oxidative stress, regulates cell fate after DNA damage and also has a pivotal role in the maintenance of nuclear and mitochondrial genomic integrity. Here, we review important evidence regarding the role played by autophagy in preventing genomic instability and tumorigenesis, as well as in micronuclei degradation. Several pathways governing autophagy activation after DNA injury and the influence of autophagy upon the processing of genomic lesions are also discussed herein. In this line, the mechanisms by which several proteins participate in both DDR and autophagy, and the importance of this crosstalk in cancer and neurodegeneration will be presented in an integrated fashion. At last, we present a hypothetical model of the role played by autophagy in dictating cell fate after genotoxic stress.
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Chang MJ, Xiao JH, Wang Y, Yan YL, Yang J, Wang JL. 2, 3, 5, 4'-Tetrahydroxystilbene-2-O-beta-D-glucoside improves gastrointestinal motility disorders in STZ-induced diabetic mice. PLoS One 2012; 7:e50291. [PMID: 23226517 PMCID: PMC3513302 DOI: 10.1371/journal.pone.0050291] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2012] [Accepted: 10/22/2012] [Indexed: 01/19/2023] Open
Abstract
Oxidative stress has recently been considered as a pivotal player in the pathogenesis of diabetic gastrointestinal dysfunction. We therefore investigated the role of 2, 3, 5, 4'-tetrahydroxystilbene-2-O-beta-D-glucoside (THSG) that has a strong anti-oxidant property, in diabetic gastrointestinal dysmotility as well as the underlying protective mechanisms. THSG restored the delayed gastric emptying and the increased intestinal transit in streptozotocin (STZ)-induced diabetic mice. Loss of neuronal nitric oxide synthase (nNOS) expression and impaired nonadrenergic, noncholinergic (NANC) relaxations in diabetic mice were relieved by long-term preventive treatment with THSG. Meanwhile, THSG (10(-7)~10(-4) mol/L) enhanced concentration-dependently NANC relaxations of isolated colons in diabetic mice. Diabetic mice displayed a significant increase in Malondialdehyde (MDA) level and decrease in the activity of glutathione peroxidase (GSH-Px), which were ameliorated by THSG. Inhibition of caspase-3 and activation of ERK phosphorylation related MAPK pathway were involved in prevention of enhanced apoptosis in diabetes afforded by THSG. Moreover, THSG prevented the significant decrease in PPAR-γ and SIRT1 expression in diabetic ileum. Our study indicates that THSG improves diabetic gastrointestinal disorders through activation of MAPK pathway and upregulation of PPAR-γ and SIRT1.
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Affiliation(s)
- Mu-Jun Chang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Jun-Hua Xiao
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Yong Wang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Yong-Li Yan
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Jun Yang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
| | - Jia-Ling Wang
- Department of Pharmacology, Tongji Medical College, Huazhong University of Science and Technology, Hangkong Rode, Wuhan, China
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15
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Abstract
Pyridine nucleotides (PNs), such as NAD(H) and NADP(H), mediate electron transfer in many catabolic and anabolic processes. In general, NAD(+) and NADP(+) receive electrons to become NADH and NADPH by coupling with catabolic processes. These electrons are utilized for biologically essential reactions such as ATP production, anabolism and cellular oxidation-reduction (redox) regulation. Thus, in addition to ATP, NADH and NADPH could be defined as high-energy intermediates and "molecular units of currency" in energy transfer. We discuss the significance of PNs as energy/electron transporters and signal transducers, in regulating cell death and/or survival processes. In the first part of this review, we describe the role of NADH and NADPH as electron donors for NADPH oxidases (Noxs), glutathione (GSH), and thioredoxin (Trx) systems in cellular redox regulation. Noxs produce superoxide/hydrogen peroxide yielding oxidative environment, whereas GSH and Trx systems protect against oxidative stress. We then describe the role of NAD(+) and NADH as signal transducers through NAD(+)-dependent enzymes such as PARP-1 and Sirt1. PARP-1 is activated by damaged DNA in order to repair the DNA, which attenuates energy production through NAD(+) consumption; Sirt1 is activated by an increased NAD(+)/NADH ratio to facilitate signal transduction for metabolic adaption as well as stress responses. We conclude that PNs serve as an important interface for distinct cellular responses, including stress response, energy metabolism, and cell survival/death.
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Affiliation(s)
- Shin-Ichi Oka
- Cardiovascular Research Institute, UMDNJ-Newark, 185 S Orange Ave, MSB G609, Newark, NJ 07103, USA
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16
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Massudi H, Grant R, Braidy N, Guest J, Farnsworth B, Guillemin GJ. Age-associated changes in oxidative stress and NAD+ metabolism in human tissue. PLoS One 2012; 7:e42357. [PMID: 22848760 PMCID: PMC3407129 DOI: 10.1371/journal.pone.0042357] [Citation(s) in RCA: 378] [Impact Index Per Article: 31.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/09/2012] [Accepted: 07/04/2012] [Indexed: 01/07/2023] Open
Abstract
Nicotinamide adenine dinucleotide (NAD+) is an essential electron transporter in mitochondrial respiration and oxidative phosphorylation. In genomic DNA, NAD+ also represents the sole substrate for the nuclear repair enzyme, poly(ADP-ribose) polymerase (PARP) and the sirtuin family of NAD-dependent histone deacetylases. Age associated increases in oxidative nuclear damage have been associated with PARP-mediated NAD+ depletion and loss of SIRT1 activity in rodents. In this study, we further investigated whether these same associations were present in aging human tissue. Human pelvic skin samples were obtained from consenting patients aged between 15–77 and newborn babies (0–1 year old) (n = 49) previously scheduled for an unrelated surgical procedure. DNA damage correlated strongly with age in both males (p = 0.029; r = 0.490) and females (p = 0.003; r = 0.600) whereas lipid oxidation (MDA) levels increased with age in males (p = 0.004; r = 0.623) but not females (p = 0.3734; r = 0.200). PARP activity significantly increased with age in males (p<0.0001; r = 0.768) and inversely correlated with tissue NAD+ levels (p = 0.0003; r = −0.639). These associations were less evident in females. A strong negative correlation was observed between NAD+ levels and age in both males (p = 0.001; r = −0.706) and females (p = 0.01; r = −0.537). SIRT1 activity also negatively correlated with age in males (p = 0.007; r = −0.612) but not in females. Strong positive correlations were also observed between lipid peroxidation and DNA damage (p<0.0001; r = 0.4962), and PARP activity and NAD+ levels (p = 0.0213; r = 0.5241) in post pubescent males. This study provides quantitative evidence in support of the hypothesis that hyperactivation of PARP due to an accumulation of oxidative damage to DNA during aging may be responsible for increased NAD+ catabolism in human tissue. The resulting NAD+ depletion may play a major role in the aging process, by limiting energy production, DNA repair and genomic signalling.
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Affiliation(s)
- Hassina Massudi
- Department of Pharmacology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
- Australasian Research Institute, Sydney Adventist Hospital, Sydney, New South Wales, Australia
| | - Ross Grant
- Department of Pharmacology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
- Australasian Research Institute, Sydney Adventist Hospital, Sydney, New South Wales, Australia
- * E-mail:
| | - Nady Braidy
- Department of Pharmacology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
- School of Psychiatry, University of New South Wales, Faculty of Medicine, Sydney, New South Wales, Australia
| | - Jade Guest
- Department of Pharmacology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
- Australasian Research Institute, Sydney Adventist Hospital, Sydney, New South Wales, Australia
| | - Bruce Farnsworth
- Australasian Research Institute, Sydney Adventist Hospital, Sydney, New South Wales, Australia
| | - Gilles J. Guillemin
- Department of Pharmacology, School of Medical Sciences, Faculty of Medicine, University of New South Wales, Sydney, New South Wales, Australia
- St Vincent's Centre for Applied Medical Research, Sydney, New South Wales, Australia
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Xie Y, Zhang J, Ye S, He M, Ren R, Yuan D, Shao C. SirT1 regulates radiosensitivity of hepatoma cells differently under normoxic and hypoxic conditions. Cancer Sci 2012; 103:1238-44. [PMID: 22448750 DOI: 10.1111/j.1349-7006.2012.02285.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/25/2011] [Revised: 01/10/2012] [Accepted: 03/21/2012] [Indexed: 01/07/2023] Open
Abstract
Intratumoral hypoxic cells are more resistant to radiotherapy due to a reduction in lifespan of DNA-damaging free radicals and augmentation of post-irradiation molecular restoration. SirT1, a member of the mammalian sirtuin family, deacetylates various transcription factors to trigger cell defense and survival in response to stresses and DNA damage. In this study, we provide new evidence indicating that overexpression of SirT1 in hepatoma HepG2 cells allowed the cells to become much more resistant to irradiation under hypoxia than under normoxia. When SirT1 was knocked down in both HepG2 and SK-Hep-1 cells, the radiosensitivity was increased, especially under hypoxia. But this enhanced radiosensitivity in SirT1-deficient cells was extensively decreased by infecting cells with c-Myc siRNA. Furthermore, the expression of c-Myc protein and its acetylation were increased in the SirT1 knockdown cells and these increments under hypoxic conditions were much more notable than under normoxia. In addition, c-Myc interference significantly suppressed phosphorylated p53 protein expression after irradiation, especially under hypoxic conditions. The current findings indicate that SirT1 confers a higher radioresistance in hypoxic cells than in normoxic cells due to the decreased levels of c-Myc protein and its acetylation, and that a c-Myc-dependent radiation-induced phosphorylated p53 may be involved. SirT1 could serve as a novel target of radiation damage and thus as a potential strategy to advance the efficiency of radiotherapy in hepatoma entities.
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Affiliation(s)
- Yuexia Xie
- Institute of Radiation Medicine, Fudan University, Shanghai, China
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18
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Dancy BCR, Ming SA, Papazyan R, Jelinek CA, Majumdar A, Sun Y, Dancy BM, Drury WJ, Cotter RJ, Taverna SD, Cole PA. Azalysine analogues as probes for protein lysine deacetylation and demethylation. J Am Chem Soc 2012; 134:5138-48. [PMID: 22352831 PMCID: PMC3313494 DOI: 10.1021/ja209574z] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
Reversible lysine acetylation and methylation regulate the function of a wide variety of proteins, including histones. Here, we have synthesized azalysine-containing peptides in acetylated and unacetylated forms as chemical probes of the histone deacetylases (HDAC8, Sir2Tm, and SIRT1) and the histone demethylase, LSD1. We have shown that the acetyl-azalysine modification is a fairly efficient substrate for the sirtuins, but a weaker substrate for HDAC8, a classical HDAC. In addition to deacetylation by sirtuins, the acetyl-azalysine analogue generates a novel ADP-ribose adduct that was characterized by mass spectrometry, Western blot analysis, and nuclear magnetic resonance spectroscopy. This peptide-ADP-ribose adduct is proposed to correspond to a derailed reaction intermediate, providing unique evidence for the direct 2'-hydroxyl attack on the O-alkylimidate intermediate that is formed in the course of sirtuin catalyzed deacetylation. An unacetylated azalysine-containing H3 peptide proved to be a potent inhibitor of the LSD1 demethylase, forming an FAD adduct characteristic of previously reported related structures, providing a new chemical probe for mechanistic analysis.
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Affiliation(s)
| | | | | | | | - Ananya Majumdar
- The Johns Hopkins Biomolecular NMR Center, Johns Hopkins University, Baltimore, MD 21218
| | | | | | | | | | | | - Philip A. Cole
- Corresponding Author: Philip A. Cole, Department of Pharmacology and Molecular Sciences, Johns Hopkins University School of Medicine, 725 N. Wolfe St, 316 Hunterian Building, Baltimore, MD 21205, Tel: 410-614-8849/614-0540, Fax: 410-955-3023,
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Kirpich I, Ghare S, Zhang J, Gobejishvili L, Kharebava G, Barve SJ, Barker D, Moghe A, McClain CJ, Barve S. Binge alcohol-induced microvesicular liver steatosis and injury are associated with down-regulation of hepatic Hdac 1, 7, 9, 10, 11 and up-regulation of Hdac 3. Alcohol Clin Exp Res 2012; 36:1578-86. [PMID: 22375794 DOI: 10.1111/j.1530-0277.2012.01751.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2011] [Accepted: 12/18/2011] [Indexed: 12/26/2022]
Abstract
BACKGROUND Binge, as well as chronic, alcohol consumption affects global histone acetylation leading to changes in gene expression. It is becoming increasingly evident that these histone-associated epigenetic modifications play an important role in the development of alcohol-mediated hepatic injury. METHODS C57BL/6 mice were gavaged 3 times (12-hour intervals) with ethanol (EtOH; 4.5 g/kg). Hepatic histone deacetylase (Hdac) mRNAs were assessed by qRT-PCR. Total HDAC activity was estimated by a colorimetric HDAC activity/inhibition assay. Histone acetylation levels were evaluated by Western blot. Liver steatosis and injury were evaluated by histopathology, plasma aminotransferase (ALT) activity, and liver triglyceride accumulation. Expression of fatty acid synthase (Fas) and carnitine palmitoyl transferase 1a (Cpt1a) was also examined. HDAC 9 association with Fas promoter was analyzed. RESULTS Binge alcohol exposure resulted in alterations of hepatic Hdac mRNA levels. Down-regulation of HDAC Class I (Hdac 1), Class II (Hdac 7, 9, 10), and Class IV (Hdac 11) and up-regulation of HDAC Class I (Hdac 3) gene expression were observed. Correspondent to the decrease in HDAC activity, an increase in hepatic histone acetylation was observed. These molecular events were associated with microvesicular hepatic steatosis and injury characterized by increased hepatic triglycerides (48.02 ± 3.83 vs. 19.90 ± 3.48 mg/g liver, p < 0.05) and elevated plasma ALT activity (51.98 ± 6.91 vs. 20.8 ± 0.62 U/l, p < 0.05). Hepatic steatosis was associated with an increase in FAS and a decrease in CPT1a mRNA and protein expression. Fas promoter analysis revealed that binge EtOH treatment decreased HDAC 9 occupancy at the Fas promoter resulting in its transcriptional activation. CONCLUSIONS Deregulation of hepatic Hdac expression likely plays a major role in the binge alcohol-induced hepatic steatosis and liver injury by affecting lipogenesis and fatty acid β-oxidation.
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Affiliation(s)
- Irina Kirpich
- Division of Gastroenterology, Hepatology, and Nutrition, Department of Medicine, University of Louisville School of Medicine, Kentucky, USA
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Kirkland JB. Niacin status and genomic instability in bone marrow cells; mechanisms favoring the progression of leukemogenesis. Subcell Biochem 2012; 56:21-36. [PMID: 22116692 DOI: 10.1007/978-94-007-2199-9_2] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 05/31/2023]
Abstract
Niacin deficiency causes dramatic genomic instability in bone marrow cells in an in vivo rat model. The end result is seen in the increased incidence of sister chromatid exchanges, micronuclei, chromosomal aberrations and the eventual development of nitrosourea-induced leukemias. From a mechanistic perspective, niacin deficiency delays excision repair and causes double strand break accumulation, which in turn favor chromosome breaks and translocations. Niacin deficiency also impairs cell cycle arrest and apoptosis in response to DNA damage, which combine to encourage the survival of cells with leukemogenic potential. Niacin deficiency also enhances the level of oxidant damage found in cellular proteins and DNA, but not through depression of GSH levels. Pharmacological supplementation of niacin decreases the development of nitrosourea-induced leukemias, while short term effects of high niacin intake include a large increase in cellular NAD+ and poly(ADP-ribose) content and enhanced apoptosis. These results are important to cancer patients, which tend to be niacin deficient, are exposed to large doses of genotoxic drugs, and suffer short-term bone marrow suppression and long-term development of secondary leukemias. The data from our rat model suggest that niacin supplementation of cancer patients may decrease the severity of short and long-term side effects, and may also improve tumor cell killing through activation of poly(ADP-ribose)-dependent apoptosis pathways.
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Affiliation(s)
- James B Kirkland
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada, N1G 2W1,
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Sancho-Pelluz J, Paquet-Durand F. HDAC inhibition prevents Rd1 mouse photoreceptor degeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2012; 723:107-13. [PMID: 22183322 DOI: 10.1007/978-1-4614-0631-0_15] [Citation(s) in RCA: 11] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
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Sancho-Pelluz J, Alavi MV, Sahaboglu A, Kustermann S, Farinelli P, Azadi S, van Veen T, Romero FJ, Paquet-Durand F, Ekström P. Excessive HDAC activation is critical for neurodegeneration in the rd1 mouse. Cell Death Dis 2011; 1:e24. [PMID: 21364632 PMCID: PMC3032332 DOI: 10.1038/cddis.2010.4] [Citation(s) in RCA: 94] [Impact Index Per Article: 7.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Inherited retinal degenerations, collectively termed retinitis pigmentosa (RP), constitute one of the leading causes of blindness in the developed world. RP is at present untreatable and the underlying neurodegenerative mechanisms are unknown, even though the genetic causes are often established. Acetylation and deacetylation of histones, carried out by histone acetyltransferases (HATs) and histone deacetylases (HDACs), respectively, affects cellular division, differentiation, death and survival. We found acetylation of histones and probably other proteins to be dramatically reduced in degenerating photoreceptors in the rd1 human homologous mouse model for RP. Using a custom developed in situ HDAC activity assay, we show that overactivation of HDAC classes I/II temporally precedes photoreceptor degeneration. Moreover, pharmacological inhibition of HDACs I/II activity in rd1 organotypic retinal explants decreased activity of poly-ADP-ribose-polymerase and strongly reduced photoreceptor cell death. These findings highlight the importance of protein acetylation for photoreceptor cell death and survival and propose certain HDAC classes as novel targets for the pharmacological intervention in RP.
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Affiliation(s)
- J Sancho-Pelluz
- Division of Experimental Ophthalmology, Institute for Ophthalmic Research, University of Tübingen, Tübingen, Germany
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Abstract
It has long been understood that many of the same manipulations that increase longevity in Caenorhabditis elegans also increase resistance to various acute stressors, and vice-versa; moreover these findings hold in more complex organisms as well. Nevertheless, the mechanistic relationship between these phenotypes remains unclear, and in many cases the overlap between stress resistance and longevity is inexact. Here we review the known connections between stress resistance and longevity, discuss instances in which these connections are absent, and summarize the theoretical explanations that have been posited for these phenomena.
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Affiliation(s)
- Katherine I. Zhou
- Department of Molecular, Cellular and Developmental Biology, PO Box 208103, Yale University, New Haven, CT 06520
| | - Zachary Pincus
- Department of Molecular, Cellular and Developmental Biology, PO Box 208103, Yale University, New Haven, CT 06520
| | - Frank J. Slack
- Department of Molecular, Cellular and Developmental Biology, PO Box 208103, Yale University, New Haven, CT 06520
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Mandrekar P. Epigenetic regulation in alcoholic liver disease. World J Gastroenterol 2011; 17:2456-64. [PMID: 21633650 PMCID: PMC3103803 DOI: 10.3748/wjg.v17.i20.2456] [Citation(s) in RCA: 65] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/20/2011] [Revised: 03/02/2011] [Accepted: 03/09/2011] [Indexed: 02/06/2023] Open
Abstract
Alcoholic liver disease (ALD) is characterized by steatosis or fat deposition in the liver and inflammation, which leads to cirrhosis and hepatocellular carcinoma. Induction of target genes without involving changes in DNA sequence seems to contribute greatly to liver injury. Chromatin modifications including alterations in histones and DNA, as well as post-transcriptional changes collectively referred to as epigenetic effects are altered by alcohol. Recent studies have pointed to a significant role for epigenetic mechanisms at the nucleosomal level influencing gene expression and disease outcome in ALD. Specifically, epigenetic alterations by alcohol include histone modifications such as changes in acetylation and phosphorylation, hypomethylation of DNA, and alterations in miRNAs. These modifications can be induced by alcohol-induced oxidative stress that results in altered recruitment of transcriptional machinery and abnormal gene expression. Delineating these mechanisms in initiation and progression of ALD is becoming a major area of interest. This review summarizes key epigenetic mechanisms that are dysregulated by alcohol in the liver. Alterations by alcohol in histone and DNA modifications, enzymes related to histone acetylation such as histone acetyltransferases, histone deacetylases and sirtuins, and methylation enzymes such as DNA methyltransferases are discussed. Chromatin modifications and miRNA alterations that result in immune cell dysfunction contributing to inflammatory cytokine production in ALD is reviewed. Finally, the role of alcohol-mediated oxidative stress in epigenetic regulation in ALD is described. A better understanding of these mechanisms is crucial for designing novel epigenetic based therapies to ameliorate ALD.
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25
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Maiese K, Chong ZZ, Shang YC, Hou J. Novel avenues of drug discovery and biomarkers for diabetes mellitus. J Clin Pharmacol 2011; 51:128-52. [PMID: 20220043 PMCID: PMC3033756 DOI: 10.1177/0091270010362904] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Globally, developed nations spend a significant amount of their resources on health care initiatives that poorly translate into increased population life expectancy. As an example, the United States devotes 16% of its gross domestic product to health care, the highest level in the world, but falls behind other nations that enjoy greater individual life expectancy. These observations point to the need for pioneering avenues of drug discovery to increase life span with controlled costs. In particular, innovative drug development for metabolic disorders such as diabetes mellitus becomes increasingly critical given that the number of diabetic people will increase exponentially over the next 20 years. This article discusses the elucidation and targeting of novel cellular pathways that are intimately tied to oxidative stress in diabetes mellitus for new treatment strategies. Pathways that involve wingless, β-nicotinamide adenine dinucleotide (NAD(+)) precursors, and cytokines govern complex biological pathways that determine both cell survival and longevity during diabetes mellitus and its complications. Furthermore, the role of these entities as biomarkers for disease can further enhance their utility irrespective of their treatment potential. Greater understanding of the intricacies of these unique cellular mechanisms will shape future drug discovery for diabetes mellitus to provide focused clinical care with limited or absent long-term complications.
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Affiliation(s)
- Kenneth Maiese
- Department of Neurology, 8C-1 UHC, Wayne State University School of Medicine, 4201 St. Antoine, Detroit, MI 48201, USA.
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Wang C, Tian L, Popov VM, Pestell RG. Acetylation and nuclear receptor action. J Steroid Biochem Mol Biol 2011; 123:91-100. [PMID: 21167281 PMCID: PMC3056342 DOI: 10.1016/j.jsbmb.2010.12.003] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/14/2010] [Revised: 12/03/2010] [Accepted: 12/06/2010] [Indexed: 01/06/2023]
Abstract
Acetylation is an essential post-translational modification featuring an acetyl group that is covalently conjugated to a protein substrate. Histone acetylation was first proposed nearly half a century ago by Dr. Vincent Allfrey. Subsequent studies have shown that the acetylated core histones are often associated with transcriptionally active chromatin. Acetylation at lysine residues of histone tails neutralizes the positive charge, which decreases their binding ability to DNA and increases the accessibility of transcription factors and coactivators to the chromatin template. In addition to histones, a number of non-histone substrates are acetylated. Acetylation of non-histone proteins governs biological processes, such as cellular proliferation and survival, transcriptional activity, and intracellular trafficking. We demonstrated that acetylation of transcription factors can regulate cellular growth. Furthermore, we showed that nuclear receptors (NRs) are acetylated at a phylogenetically conserved motif. Since our initial observations with the estrogen and androgen receptors, more than a dozen NRs have been shown to function as substrates for acetyltransferases with diverse functional consequences. This review focuses on the acetylation of NRs and the effect of acetylation on NR function. We discuss the potential role of acetylation in disease initiation and progression with an emphasis on tumorigenesis.
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Affiliation(s)
- Chenguang Wang
- Department of Stem Cell Biology and Regenerative Medicine, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10th Street, Philadelphia, PA 19107, USA
| | - Lifeng Tian
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10th Street, Philadelphia, PA 19107, USA
| | - Vladimir M. Popov
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10th Street, Philadelphia, PA 19107, USA
| | - Richard G. Pestell
- Department of Cancer Biology, Kimmel Cancer Center, Thomas Jefferson University, 233 S. 10th Street, Philadelphia, PA 19107, USA
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Robers MB, Loh C, Carlson CB, Yang H, Frey EA, Hermanson SB, Bi K. Measurement of the cellular deacetylase activity of SIRT1 on p53 via LanthaScreen® technology. MOLECULAR BIOSYSTEMS 2010; 7:59-66. [PMID: 20931131 DOI: 10.1039/c0mb00026d] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Upon genomic insult, the tumor suppressor p53 is phosphorylated and acetylated at specific serine and lysine residues, increasing its stability and transactivation function. Deacetylases, including the type III histone deacetylase SIRT1, remove acetyl groups from p53 and counterbalance acetyltransferase activity during a DNA damage response. This report describes a series of high-throughput LanthaScreen® time-resolved Förster resonance energy transfer (TR-FRET) immunoassays for detection of intracellular p53 phosphorylation of Ser15 and acetylation of Lys382 upon treatment with DNA damage agents, such as etoposide. These assays were used to measure the deacetylase activity of SIRT1 and/or Type I/II Histone deacetylases (HDACs). First, BacMam-mediated overexpression of SIRT1 resulted in dose-dependent deacetylation of GFP-p53 following etoposide treatment of U-2 OS cells, confirming that GFP-p53 serves as a SIRT1 substrate in this assay format. Further, overexpression of the acetyltransferase p300 via BacMam increased the acetylation of GFP-p53 at Lys382. Next, siRNA-mediated knockdown of SIRT1 resulted in increased GFP-p53 acetylation, indicating that endogenous SIRT1 activity can also be measured in U-2 OS cells. Consistent with these results, GFP-p53 acetylation was also increased upon treatment of cells with a small-molecule inhibitor of SIRT1, EX-527. The effect of this compound was dramatically increased when used in combination with chemotherapeutic drug and/or the HDAC inhibitor Trichostatin A, confirming a proposed synergistic mechanism of p53 deacetylation by SIRT1 and Type I/II HDACs. Taken together, the cellular assays described here can be used as high-throughput alternatives to traditional immunoassays such as western blotting for identifying pharmacological modulators of specific p53-modifying enzymes.
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Affiliation(s)
- Matthew B Robers
- Discovery Assays and Services, Life Technologies Corporation, Madison, WI 53719, USA
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Small molecule modulators of histone acetylation and methylation: a disease perspective. BIOCHIMICA ET BIOPHYSICA ACTA-GENE REGULATORY MECHANISMS 2010; 1799:810-28. [PMID: 20888936 DOI: 10.1016/j.bbagrm.2010.09.005] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/18/2010] [Revised: 09/18/2010] [Accepted: 09/24/2010] [Indexed: 11/22/2022]
Abstract
Chromatin modifications have gained immense significance in the past few decades as key regulators of gene expression. The enzymes responsible for these modifications along with the other non-histone proteins, remodeling factors and small RNAs modulate the chromatin dynamicity, which in turn directs the chromatin function. A concerted action of different modifying enzymes catalyzes these modifications, which are read by effector modules and converted to functional outcomes by various protein complexes. Several small molecules in the physiological system such as acetyl CoA, NAD(+), and ATP are actively involved in regulating these functional outcomes. Recent understanding in the field of epigenetics indicate the possibility of the existence of a network, 'the epigenetic language' involving cross talk among different modifications that could regulate cellular processes like transcription, replication and repair. Hence, these modifications are essential for the cellular homeostasis, and any alteration in this balance leads to a pathophysiological condition or disease manifestation. Therefore, it is becoming more evident that modulators of these modifying enzymes could be an attractive therapeutic strategy, popularly referred to as 'Epigenetic therapy.' Although this field is currently monopolized by DNA methylation and histone deacetylase inhibitors, this review highlights the modulators of the other modifications namely histone acetylation, lysine methylation and arginine methylation and argues in favor of their therapeutic potential.
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Fan W, Luo J. SIRT1 Regulates UV-Induced DNA Repair through Deacetylating XPA. Mol Cell 2010; 39:247-58. [DOI: 10.1016/j.molcel.2010.07.006] [Citation(s) in RCA: 174] [Impact Index Per Article: 12.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2009] [Revised: 04/13/2010] [Accepted: 06/02/2010] [Indexed: 11/26/2022]
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Maiese K, Shang YC, Chong ZZ, Hou J. Diabetes mellitus: channeling care through cellular discovery. Curr Neurovasc Res 2010; 7:59-64. [PMID: 20158461 DOI: 10.2174/156720210790820217] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2009] [Accepted: 12/29/2009] [Indexed: 12/13/2022]
Abstract
Diabetes mellitus (DM) impacts a significant portion of the world's population and care for this disorder places an economic burden on the gross domestic product for any particular country. Furthermore, both Type 1 and Type 2 DM are becoming increasingly prevalent and there is increased incidence of impaired glucose tolerance in the young. The complications of DM are protean and can involve multiple systems throughout the body that are susceptible to the detrimental effects of oxidative stress and apoptotic cell injury. For these reasons, innovative strategies are necessary for the implementation of new treatments for DM that are generated through the further understanding of cellular pathways that govern the pathological consequences of DM. In particular, both the precursor for the coenzyme beta-nicotinamide adenine dinucleotide (NAD(+)), nicotinamide, and the growth factor erythropoietin offer novel platforms for drug discovery that involve cellular metabolic homeostasis and inflammatory cell control. Interestingly, these agents and their tightly associated pathways that consist of cell cycle regulation, protein kinase B, forkhead transcription factors, and Wnt signaling also function in a broader sense as biomarkers for disease onset and progression.
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Affiliation(s)
- Kenneth Maiese
- Division of Cellular and Molecular Cerebral Ischemia, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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Voghel G, Thorin-Trescases N, Mamarbachi AM, Villeneuve L, Mallette FA, Ferbeyre G, Farhat N, Perrault LP, Carrier M, Thorin E. Endogenous oxidative stress prevents telomerase-dependent immortalization of human endothelial cells. Mech Ageing Dev 2010; 131:354-63. [PMID: 20399802 DOI: 10.1016/j.mad.2010.04.004] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2010] [Revised: 02/26/2010] [Accepted: 04/09/2010] [Indexed: 10/19/2022]
Abstract
INTRODUCTION With aging, oxidative stress accelerates vascular endothelial cell (EC) telomere shortening-induced senescence, and may promote atherosclerosis in humans. Our aim was to investigate whether an antioxidant treatment combined with telomerase (hTERT) over-expression would prevent senescence of EC isolated from patients with severe atherosclerosis. METHODS Cells were isolated from internal mammary arteries (n=11 donors), cultured until senescence with or without N-acetylcystein (NAC) and infected, or not, with a lentivirus over-expressing hTERT. RESULTS Compared to control EC, hTERT-NAC cells had increased telomerase activity, longer telomeres and underwent more cell divisions. According to the donor, hTERT-NAC either delayed (n=5) or prevented (n=4) EC senescence, the latter leading to cell immortalization. Lack of cell immortalization by hTERT-NAC was accompanied by an absence of beneficial effect of NAC alone in paired EC. Accordingly, lack of EC immortalization by hTERT-NAC was associated with high endogenous susceptibility to oxidation. In EC where hTERT-NAC did not immortalize EC, p53, p21 and p16 expression increased with senescence, while oxidative-dependent DNA damage associated with senescence was not prevented. CONCLUSION Our data suggest that irreversible oxidative stress-dependent damages associated with cardiovascular risk factors are responsible for senescence of EC from atherosclerotic patients.
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Affiliation(s)
- Guillaume Voghel
- Department of Surgery, Research Center, Montreal Heart Institute, Université de Montréal, Montréal, Québec, Canada
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Morandi E, Severini C, Quercioli D, Perdichizzi S, Mascolo MG, Horn W, Vaccari M, Nucci MC, Lodi V, Violante FS, Bolognesi C, Grilli S, Silingardi P, Colacci A. Gene expression changes in medical workers exposed to radiation. Radiat Res 2009; 172:500-8. [PMID: 19772471 DOI: 10.1667/rr1545.1] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/03/2022]
Abstract
The use of nuclear resources for medical purposes causes considerable concern about occupational exposure. Nevertheless, little information is available regarding the effects of low-dose irradiations protracted over time. We used oligomicroarrays to identify the genes that are transcriptionally regulated by persistent exposure to extremely low doses of ionizing radiation in 28 exposed professionals (mean cumulative effective dose +/- SD, 19 +/- 38 mSv) compared with a matched sample of nonexposed subjects. We identified 256 modulated genes from peripheral blood mononuclear cells profiles, and the main biological processes we found were DNA packaging and mitochondrial electron transport NADH to ubiquinone. Next we investigated whether a different pattern existed when only 22 exposed subjects with accumulated doses >2.5 mSv, a threshold corresponding to the natural background radiation in Italy per year, and mean equal to 25 +/- 41 mSv were used. In addition to DNA packaging and NADH dehydrogenase function, the analysis of the higher-exposed subgroup revealed a significant modulation of ion homeostasis and programmed cell death as well. The changes in gene expression that we found suggest different mechanisms from those involved in high-dose studies that may help to define new biomarkers of radiation exposure for accumulated doses below 25 mSv.
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Affiliation(s)
- Elena Morandi
- Environmental Carcinogenesis and Risk Assessment, Environmental Protection and Health Prevention Agency-Emilia-Romagna Region (ER-EPA), 40126, Bologna County, Italy
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Maiese K, Chong ZZ, Hou J, Shang YC. The vitamin nicotinamide: translating nutrition into clinical care. Molecules 2009; 14:3446-85. [PMID: 19783937 PMCID: PMC2756609 DOI: 10.3390/molecules14093446] [Citation(s) in RCA: 173] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2009] [Revised: 09/08/2009] [Accepted: 09/08/2009] [Indexed: 12/13/2022] Open
Abstract
Nicotinamide, the amide form of vitamin B(3) (niacin), is changed to its mononucleotide compound with the enzyme nicotinic acide/nicotinamide adenylyltransferase, and participates in the cellular energy metabolism that directly impacts normal physiology. However, nicotinamide also influences oxidative stress and modulates multiple pathways tied to both cellular survival and death. During disorders that include immune system dysfunction, diabetes, and aging-related diseases, nicotinamide is a robust cytoprotectant that blocks cellular inflammatory cell activation, early apoptotic phosphatidylserine exposure, and late nuclear DNA degradation. Nicotinamide relies upon unique cellular pathways that involve forkhead transcription factors, sirtuins, protein kinase B (Akt), Bad, caspases, and poly (ADP-ribose) polymerase that may offer a fine line with determining cellular longevity, cell survival, and unwanted cancer progression. If one is cognizant of the these considerations, it becomes evident that nicotinamide holds great potential for multiple disease entities, but the development of new therapeutic strategies rests heavily upon the elucidation of the novel cellular pathways that nicotinamide closely governs.
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Affiliation(s)
- Kenneth Maiese
- Division of Cellular and Molecular Cerebral Ischemia, Wayne State University School of Medicine, Detroit, Michigan 48201, USA.
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Nakamaru Y, Vuppusetty C, Wada H, Milne JC, Ito M, Rossios C, Elliot M, Hogg J, Kharitonov S, Goto H, Bemis JE, Elliott P, Barnes PJ, Ito K. A protein deacetylase SIRT1 is a negative regulator of metalloproteinase-9. FASEB J 2009; 23:2810-9. [PMID: 19376817 DOI: 10.1096/fj.08-125468] [Citation(s) in RCA: 172] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Inappropriate elevation of matrix metalloproteinase-9 (MMP9) is reported to be involved in the pathogenesis of chronic obstructive pulmonary disease (COPD). The object of this study was to identify the molecular mechanism underlying this increase of MMP9 expression, and here we show that oxidative stress-dependent reduction of a protein deacetylase, SIRT1, known as a putative antiaging enzyme, causes elevation of MMP9 expression. A sirtuin inhibitor, splitomycin, and SIRT1 knockdown by RNA interference led an increase in MMP9 expression in human monocytic U937 cells and in primary sputum macrophages, which was detected by RT-PCR, Western blot, activity assay, and zymography. In fact, the SIRT1 level was significantly decreased in peripheral lungs of patients with COPD, and this increase was inversely correlated with MMP9 expression and MMP9 promoter activation detected by a chromatin immunoprecipitation assay. H(2)O(2) reduced SIRT1 expression and activity in U937 cells; furthermore, cigarette smoke exposure also caused reduction of SIRT1 expression in lung tissue of A/J mice, with concomitant elevation of MMP9. Intranasal treatment of a selective and novel SIRT1 small molecule activator, SRT2172, blocked the increase of MMP9 expression in the lung as well as pulmonary neutrophilia and the reduction in exercise tolerance. Thus, SIRT1 is a negative regulator of MMP9 expression, and SIRT1 activation is implicated as a novel therapeutic approach to treating chronic inflammatory diseases, in which MMP9 is abundant.
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Affiliation(s)
- Yuji Nakamaru
- Airway Disease Section, National Heart and Lung Institute, Imperial College, London, UK
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Abstract
Chemotherapy often causes damage to hematopoietic tissues, leading to acute bone marrow suppression and the long term development of leukemias. Niacin deficiency, which is common in cancer patients, causes dramatic genomic instability in bone marrow cells in an in vivo rat model. From a mechanistic perspective, niacin deficiency delays excision repair and causes double strand break accumulation, which in turn favors chromosome breaks and translocations. Niacin deficiency also impairs cell cycle arrest and apoptosis in response to DNA damage, which combine to encourage the survival of cells with leukemogenic potential. Conversely, pharmacological supplementation of rats with niacin increases bone marrow poly(ADP-ribose) formation and apoptosis. Improvement of niacin status in rats significantly decreased nitrosourea-induced leukemia incidence. The data from our rat model suggest that niacin supplementation of cancer patients may decrease the severity of short- and long-term side effects of chemotherapy, and could improve tumor cell killing through activation of poly(ADP-ribose)-dependent apoptosis pathways.
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Liu FC, Liao CH, Chang YW, Liou JT, Day YJ. Splitomicin suppresses human platelet aggregation via inhibition of cyclic AMP phosphodiesterase and intracellular Ca++ release. Thromb Res 2009; 124:199-207. [PMID: 19327818 DOI: 10.1016/j.thromres.2009.02.013] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2008] [Revised: 02/11/2009] [Accepted: 02/19/2009] [Indexed: 01/03/2023]
Abstract
Splitomicin is derived from beta-naphthol and is an inhibitor of Silent Information Regulator 2 (SIR2). Its naphthoic moiety might be responsible for its inhibitory effects on platelets. The major goal of our study was to examine possible mechanisms of action of splitomicin on platelet aggregation in order to promote development of a novel anti-platelet aggregation therapy for cardiovascular and cerebrovascular diseases. To study the inhibitory effects of splitomicin on platelet aggregation, we used washed human platelets, and monitored platelet aggregation and ATP release induced by thrombin (0.1 U/ml), collagen (2 microg/ml), arachidonic acid (AA) (0.5 mM), U46619 (2 microM) or ADP (10 microM). Splitomicin inhibited platelet aggregation induced by thrombin, collagen, AA and U46619 with a concentration dependent manner. Splitomicin increased cAMP and this effect was enhanced when splitomicin (150 microM) was combined with PGE1 (0.5 microM). It did not further increase cAMP when combined with IBMX. This data indicated that splitomicin increases cAMP by inhibiting activity of phosphodiestease. In addition, splitomicin (300 microM) attenuated intracellular Ca(++) mobilization, and production of thromboxane B2 (TXB2) in platelets that was induced by thrombin, collagen, AA or U46619. The inhibitory mechanism of splitomicin on platelet aggregation may increase cyclic AMP levels via inhibition of cyclic AMP phosphodiesterase activity and subsequent inhibition of intracellular Ca(++) mobilization, TXB2 formation and ATP release.
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Affiliation(s)
- Fu-Chao Liu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Linkou, Taiwan, ROC
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Szabo C. Role of nitrosative stress in the pathogenesis of diabetic vascular dysfunction. Br J Pharmacol 2009; 156:713-27. [PMID: 19210748 DOI: 10.1111/j.1476-5381.2008.00086.x] [Citation(s) in RCA: 117] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/03/2023] Open
Abstract
Here we overview the role of reactive nitrogen species (nitrosative stress) and associated pathways in the pathogenesis of diabetic vascular complications. Increased extracellular glucose concentration, a principal feature of diabetes mellitus, induces a dysregulation of reactive oxygen and nitrogen generating pathways. These processes lead to a loss of the vascular endothelium to produce biologically active nitric oxide (NO), which impairs vascular relaxations. Mitochondria play a crucial role in this process: endothelial cells placed in increase extracellular glucose respond with a marked increase in mitochondrial superoxide formation. Superoxide, when combining with NO generated by the endothelial cells (produced by the endothelial isoform of NO synthase), leads to the formation of peroxynitrite, a cytotoxic oxidant. Reactive oxygen and nitrogen species trigger endothelial cell dysfunction through a multitude of mechanisms including substrate depletion and uncoupling of endothelial isoform of NO synthase. Another pathomechanism involves DNA strand breakage and activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP). PARP-mediated poly(ADP-ribosyl)ation and inhibition of glyceraldehyde-3-phosphate dehydrogenase importantly contributes to the development of diabetic vascular complications: it induces activation of multiple pathways of injury including activation of nuclear factor kappa B, activation of protein kinase C and generation of intracellular advanced glycation end products. Reactive species generation and PARP play key roles in the pathogenesis of 'glucose memory' and in the development of injury in endothelial cells exposed to alternating high/low glucose concentrations.
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Affiliation(s)
- Csaba Szabo
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555-0833, USA.
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Szabo C. Role of nitrosative stress in the pathogenesis of diabetic vascular dysfunction. Br J Pharmacol 2009. [PMID: 19210748 DOI: 10.111/j.1476-5381.2008.00086.x] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Here we overview the role of reactive nitrogen species (nitrosative stress) and associated pathways in the pathogenesis of diabetic vascular complications. Increased extracellular glucose concentration, a principal feature of diabetes mellitus, induces a dysregulation of reactive oxygen and nitrogen generating pathways. These processes lead to a loss of the vascular endothelium to produce biologically active nitric oxide (NO), which impairs vascular relaxations. Mitochondria play a crucial role in this process: endothelial cells placed in increase extracellular glucose respond with a marked increase in mitochondrial superoxide formation. Superoxide, when combining with NO generated by the endothelial cells (produced by the endothelial isoform of NO synthase), leads to the formation of peroxynitrite, a cytotoxic oxidant. Reactive oxygen and nitrogen species trigger endothelial cell dysfunction through a multitude of mechanisms including substrate depletion and uncoupling of endothelial isoform of NO synthase. Another pathomechanism involves DNA strand breakage and activation of the nuclear enzyme poly(ADP-ribose) polymerase (PARP). PARP-mediated poly(ADP-ribosyl)ation and inhibition of glyceraldehyde-3-phosphate dehydrogenase importantly contributes to the development of diabetic vascular complications: it induces activation of multiple pathways of injury including activation of nuclear factor kappa B, activation of protein kinase C and generation of intracellular advanced glycation end products. Reactive species generation and PARP play key roles in the pathogenesis of 'glucose memory' and in the development of injury in endothelial cells exposed to alternating high/low glucose concentrations.
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Affiliation(s)
- Csaba Szabo
- Department of Anesthesiology, The University of Texas Medical Branch, Galveston, TX 77555-0833, USA.
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39
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Liu FC, Liao CH, Chang YW, Liou JT, Day YJ. A new insight of anti-platelet effects of sirtinol in platelets aggregation via cyclic AMP phosphodiesterase. Biochem Pharmacol 2009; 77:1364-73. [PMID: 19426675 DOI: 10.1016/j.bcp.2009.01.011] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2008] [Revised: 01/15/2009] [Accepted: 01/20/2009] [Indexed: 12/21/2022]
Abstract
Sirtinol, a cell permeable six-membered lactone ring, is derived from naphthol and potent inhibitor of SIR2 and its naphtholic may have the inhibitory effects on platelets aggregation. In this study, platelet function was examined by collagen/epinephrine (CEPI) and collagen/ADP-induced closure times using the PFA-100 system reveal that CEPI-CT and CADP-CT were prolonged by sirtinol. The platelets aggregation regulated by physiological agonists such as: thrombin, collagen and AA and U46619 were significantly inhibited by sirtinol. Increases cAMP level was observed when sirtinol treated with Prostaglandin E1 in washed platelets. Moreover, sirtinol attenuated intracellular Ca(2+) release and thromboxane B2 formation stimulated by thrombin, collagen, AA and U46619 in human washed platelets. This study indicated that sirtinol could inhibit the platelet aggregation induced by physiological agonists, AA and U46619. The mechanism of action may include an increase of cAMP level with enhanced VASP-Ser157 phosphorylation via inhibition of cAMP phosphodiesterase activity and subsequent inhibition of intracellular Ca(2+) mobilization, thromboxane A2 formation, and ATP release during the platelet aggregation.
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Affiliation(s)
- Fu-Chao Liu
- Department of Anesthesiology, Chang Gung Memorial Hospital, Linkou Taiwan, ROC
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40
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Song S, McCann KE, Brown JM. Radiosensitization of yeast cells by inhibition of histone h4 acetylation. Radiat Res 2008; 170:618-627. [PMID: 18959465 DOI: 10.1667/rr1420.1] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/01/2008] [Accepted: 07/22/2008] [Indexed: 01/25/2023]
Abstract
Deletion of genes for proteins involved in histone H4 acetylation produces sensitivity to DNA-damaging agents in both Saccharomyces cerevisiae and mammalian cells. In the present studies, we show that treating wild-type yeast cells with histone acetyl transferase (HAT) inhibitors, which are chemicals that cause a global decrease in histone H4 acetylation, sensitizes the cells to ionizing radiation. Using HAT inhibitors, we have placed histone H4 acetylation into the RAD51-mediated homologous recombination repair pathway. We further show that yeast cells with functionally defective HAT proteins have normal phospho-H2A (gamma-H2A) induction after irradiation but a reduced rate of loss of gamma-H2A. This argues that HAT-defective cells are able to detect DNA double-strand breaks normally but have a defect in the repair of these lesions. We also show that cells treated with HAT inhibitors have intact G1 and G2 checkpoints after exposure to ionizing radiation, suggesting that G1 and G2 checkpoint activation is independent of histone H4 acetylation.
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Affiliation(s)
- Suisui Song
- Department of Radiation Oncology, Division of Radiation and Cancer Biology, Stanford University of School of Medicine, Stanford, California
| | - Kelly E McCann
- Department of Radiation Oncology, Division of Radiation and Cancer Biology, Stanford University of School of Medicine, Stanford, California
| | - J Martin Brown
- Department of Radiation Oncology, Division of Radiation and Cancer Biology, Stanford University of School of Medicine, Stanford, California
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41
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Bäckdahl L, Bushell A, Beck S. Inflammatory signalling as mediator of epigenetic modulation in tissue-specific chronic inflammation. Int J Biochem Cell Biol 2008; 41:176-84. [PMID: 18793748 DOI: 10.1016/j.biocel.2008.08.023] [Citation(s) in RCA: 102] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2008] [Revised: 08/18/2008] [Accepted: 08/19/2008] [Indexed: 12/19/2022]
Abstract
Recent successes of therapeutic intervention in chronic inflammatory diseases using epigenetic modifiers such as histone deacetylase inhibitors and inhibitors of DNA methylation suggest that epigenetic reprogramming plays a role in the aetiology of these diseases. The epigenetic signature of a given immune cell is reflected in the history of modifications from different signals the cell has been subjected to during differentiation. Like other cells, differentiating immune cells are dependent on a complex combination of inter- and intracell signalling as well as transcription machineries to modulate their epigenomes in order to mediate differentiation. Despite extensive research into these processes, the link between cellular signalling and epigenetic modulation remains poorly understood. Here, we review recent progress and discuss key factors driving epigenetic modulation in chronic inflammation.
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Affiliation(s)
- Liselotte Bäckdahl
- Medical Genomics Group, UCL Cancer Institute, University College London, London WC1E 6BT, UK.
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42
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Modulation of SIRT1 expression in different neurodegenerative models and human pathologies. Neuroscience 2008; 154:1388-97. [DOI: 10.1016/j.neuroscience.2008.04.065] [Citation(s) in RCA: 95] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/14/2008] [Revised: 04/21/2008] [Accepted: 04/29/2008] [Indexed: 12/26/2022]
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43
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Lee YA, Cho EJ, Yokozawa T. Protective effect of persimmon (Diospyros kaki) peel proanthocyanidin against oxidative damage under H2O2-induced cellular senescence. Biol Pharm Bull 2008; 31:1265-9. [PMID: 18520066 DOI: 10.1248/bpb.31.1265] [Citation(s) in RCA: 51] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/22/2022]
Abstract
8-Hydroxy-2'-deoxyguanosine (8-OHdG), one of the most abundant oxidative DNA adducts, is used as an indicator of oxidative DNA damage associated with aging. Among homologs of the silent information regulator (Sir), sirtuin 1 (SIRT1) is suggested as a regulator of the apoptotic response to DNA damage. Since it has been suggested that the aging process can be delayed by the attenuation of oxidative damage such as DNA damage or SIRT1 modulation, we focused on the protective effect against cellular oxidative damage of persimmon peel, a proanthocyanidin-rich food, in relation to its level of polymerization. We confirmed that 8-OHdG expression in TIG-1 human fibroblasts was increased by treatment with 300 microM H2O2 for 2 h. On the other hand, the nuclear SIRT1 level was decreased in H2O2-treated as compared with non-pretreated cells. However, pretreatments with polymers and oligomers led to a decrease in 8-OHdG and elevation in nuclear SIRT1 expression in a concentration-dependent manner. In particular, oligomers exerted a stronger effect. The present study supports the protective potential of proanthocyanidin from persimmon peel against oxidative damage under the aging process, and suggests that the polymerization of proanthocyanidin plays an important role in retarding aging in a cellular senescence model.
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Affiliation(s)
- Young A Lee
- Institute of Natural Medicine, University of Toyama, Sugitani, Toyama, Japan
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44
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Maiese K. Triple play: promoting neurovascular longevity with nicotinamide, WNT, and erythropoietin in diabetes mellitus. Biomed Pharmacother 2008; 62:218-32. [PMID: 18342481 PMCID: PMC2431130 DOI: 10.1016/j.biopha.2008.01.009] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2008] [Accepted: 01/23/2008] [Indexed: 12/17/2022] Open
Abstract
Oxidative stress is a principal pathway for the dysfunction and ultimate destruction of cells in the neuronal and vascular systems for several disease entities, not promoting the ravages of oxidative stress to any less of a degree than diabetes mellitus. Diabetes mellitus is increasing in incidence as a result of changes in human behavior that relate to diet and daily exercise and is predicted to affect almost 400 million individuals worldwide in another two decades. Furthermore, both type 1 and type 2 diabetes mellitus can lead to significant disability in the nervous and cardiovascular systems, such as cognitive loss and cardiac insufficiency. As a result, innovative strategies that directly target oxidative stress to preserve neuronal and vascular longevity could offer viable therapeutic options to diabetic patients in addition to more conventional treatments that are designed to control serum glucose levels. Here we discuss the novel application of nicotinamide, Wnt signaling, and erythropoietin that modulate cellular oxidative stress and offer significant promise for the prevention of diabetic complications in the nervous and vascular systems. Essential to this process is the precise focus upon diverse as well as common cellular pathways governed by nicotinamide, Wnt signaling, and erythropoietin to outline not only the potential benefits, but also the challenges and possible detriments of these therapies. In this way, new avenues of investigation can hopefully bypass toxic complications, or at the very least, avoid contraindications that may limit care and offer both safe and robust clinical treatment for patients.
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Affiliation(s)
- Kenneth Maiese
- Division of Cellular and Molecular Cerebral Ischemia, Wayne State University School of Medicine, Detroit, MI 48201, USA.
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45
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Stünkel W, Peh BK, Tan YC, Nayagam VM, Wang X, Salto-Tellez M, Ni B, Entzeroth M, Wood J. Function of the SIRT1 protein deacetylase in cancer. Biotechnol J 2008; 2:1360-8. [PMID: 17806102 DOI: 10.1002/biot.200700087] [Citation(s) in RCA: 179] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/02/2023]
Abstract
The NAD(+)-dependent protein deacetylase SIRT1 is linked to cellular survival pathways by virtue of keeping the tumor suppressor gene p53 and members of the forkhead transcription factor family deacetylated. To validate SIRT1 as a therapeutic anti-cancer target, we performed immunohistochemistry experiments to study the in vivo expression of SIRT1 in cancer specimens. We show that human SIRT1 is highly expressed in cancer cell lines as well as in tissue samples from colon carcinoma patients. Interestingly, there is a strong cytosolic component in the SIRT1 expression pattern. We further characterized SIRT1 in p53-wild-type and -mutant cell lines and show that SIRT1 mRNA-knockdown leads to a p53-independent decrease of cell proliferation and induction of apoptosis. In addition, SIRT1 expression has been found to be inducible upon DNA damage. A previously discovered small molecule SIRT1 inhibitor with nanomolar in vitro activity has been tested in cancer relevant assays. The SIRT1 inhibitory compound showed no potent anti-proliferative activity despite hitting its molecular target within tumor cells. From these studies we conclude that it may not be sufficient to block the catalytic function of SIRT1, and that its survival effects may be mainly brought about by means other then the deacetylase function. The increased cytosolic expression of SIRT1 in cancer cells could be an indicator of such novel functions.
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Affiliation(s)
- Walter Stünkel
- S*BIO PTE Ltd, 1 Singapore Science Park II, Singapore, Singapore
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46
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Alvira D, Yeste-Velasco M, Folch J, Verdaguer E, Canudas AM, Pallàs M, Camins A. Comparative analysis of the effects of resveratrol in two apoptotic models: inhibition of complex I and potassium deprivation in cerebellar neurons. Neuroscience 2007; 147:746-56. [PMID: 17583434 DOI: 10.1016/j.neuroscience.2007.04.029] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/22/2007] [Revised: 04/03/2007] [Accepted: 04/17/2007] [Indexed: 12/16/2022]
Abstract
The mechanism involved in neuronal apoptosis is largely unknown. Studies performed on neuronal cell cultures provide information about the pathways which orchestrate the process of neuronal loss and potential drugs for the treatment of neurological disorders. In the present study we select resveratrol, a natural antioxidant, as a potential drug for the treatment of neurodegenerative diseases. We evaluate the neuroprotective effects of resveratrol in two apoptotic models in rat cerebellar granule neurons (CGNs): the inhibition of mitochondrial complex I using 1-methyl-4-phenylpyridinium (MPP(+)) (an in vitro model of Parkinson's disease) and serum potassium withdrawal. We study the role of the mammalian silent information regulator 2 (SIRT1) in the process of neuroprotection mediated by resveratrol. Because recent studies have demonstrated that SIRT1 is involved in cell survival and has antiaging properties, we also measured changes in the expression of this protein after the addition of these two apoptotic stimuli. MPP(+)--induced loss of cell viability and apoptosis in CGNs was prevented by the addition of RESV (1 microM to 100 microM). However, the neuroprotective effects were not mediated by the activation of SIRT1, since sirtinol-an inhibitor of this enzyme--did not attenuate them. Furthermore MPP(+) decreases the protein expression of SIRT1. RESV did not prevent serum potassium withdrawal-induced apoptosis although it did completely attenuate oxidative stress production by these apoptotic stimuli. Furthermore, serum potassium withdrawal increases the expression of SIRT1. Our results indicate that the antiapoptotic effects of RESV in MPP(+) are independent of the stimulation of SIRT1 and depend on its antioxidant properties. Furthermore, because SIRT1 is involved in neuronal survival depending on the apoptotic stimuli, changes in the expression of SIRT1 could be involved in the regulation of the apoptotic route.
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Affiliation(s)
- D Alvira
- Unitat de Farmacologia i Farmacognòsia, Facultat de Farmàcia, Universitat de Barcelona, Nucli Universitari de Pedralbes, 08028 Barcelona, Spain
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47
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Schreiber V, Dantzer F, Ame JC, de Murcia G. Poly(ADP-ribose): novel functions for an old molecule. Nat Rev Mol Cell Biol 2006; 7:517-28. [PMID: 16829982 DOI: 10.1038/nrm1963] [Citation(s) in RCA: 1475] [Impact Index Per Article: 81.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
The addition to proteins of the negatively charged polymer of ADP-ribose (PAR), which is synthesized by PAR polymerases (PARPs) from NAD(+), is a unique post-translational modification. It regulates not only cell survival and cell-death programmes, but also an increasing number of other biological functions with which novel members of the PARP family have been associated. These functions include transcriptional regulation, telomere cohesion and mitotic spindle formation during cell division, intracellular trafficking and energy metabolism.
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Affiliation(s)
- Valérie Schreiber
- Département Intégrité du Génome de l'UMR 7175, Centre National de la Recherche Scientifique, Ecole Supérieure de Biotechnologie de Strasbourg, Boulevard S. Brant, BP 10413, F-67412 Illkirch Cedex, France.
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48
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Chowdari KV, Northup A, Pless L, Wood J, Joo YH, Mirnics K, Lewis DA, Levitt PR, Bacanu SA, Nimgaonkar VL. DNA pooling: a comprehensive, multi-stage association analysis of ACSL6 and SIRT5 polymorphisms in schizophrenia. GENES BRAIN AND BEHAVIOR 2006; 6:229-39. [PMID: 16827919 DOI: 10.1111/j.1601-183x.2006.00251.x] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Many candidate gene association studies have evaluated incomplete, unrepresentative sets of single nucleotide polymorphisms (SNPs), producing non-significant results that are difficult to interpret. Using a rapid, efficient strategy designed to investigate all common SNPs, we tested associations between schizophrenia and two positional candidate genes: ACSL6 (Acyl-Coenzyme A synthetase long-chain family member 6) and SIRT5 (silent mating type information regulation 2 homologue 5). We initially evaluated the utility of DNA sequencing traces to estimate SNP allele frequencies in pooled DNA samples. The mean variances for the DNA sequencing estimates were acceptable and were comparable to other published methods (mean variance: 0.0008, range 0-0.0119). Using pooled DNA samples from cases with schizophrenia/schizoaffective disorder (Diagnostic and Statistical Manual of Mental Disorders edition IV criteria) and controls (n=200, each group), we next sequenced all exons, introns and flanking upstream/downstream sequences for ACSL6 and SIRT5. Among 69 identified SNPs, case-control allele frequency comparisons revealed nine suggestive associations (P<0.2). Each of these SNPs was next genotyped in the individual samples composing the pools. A suggestive association with rs 11743803 at ACSL6 remained (allele-wise P=0.02), with diminished evidence in an extended sample (448 cases, 554 controls, P=0.062). In conclusion, we propose a multi-stage method for comprehensive, rapid, efficient and economical genetic association analysis that enables simultaneous SNP detection and allele frequency estimation in large samples. This strategy may be particularly useful for research groups lacking access to high throughput genotyping facilities. Our analyses did not yield convincing evidence for associations of schizophrenia with ACSL6 or SIRT5.
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Affiliation(s)
- K V Chowdari
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15213, USA
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