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Gong Y, Laheji F, Berenson A, Li Y, Moser A, Qian A, Frosch M, Sadjadi R, Hahn R, Maguire CA, Eichler F. Role of Basal Forebrain Neurons in Adrenomyeloneuropathy in Mice and Humans. Ann Neurol 2024; 95:442-458. [PMID: 38062617 PMCID: PMC10949091 DOI: 10.1002/ana.26849] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2023] [Revised: 11/28/2023] [Accepted: 12/05/2023] [Indexed: 12/27/2023]
Abstract
OBJECTIVE X-linked adrenoleukodystrophy is caused by mutations in the peroxisomal half-transporter ABCD1. The most common manifestation is adrenomyeloneuropathy, a hereditary spastic paraplegia of adulthood. The present study set out to understand the role of neuronal ABCD1 in mice and humans with adrenomyeloneuropathy. METHODS Neuronal expression of ABCD1 during development was assessed in mice and humans. ABCD1-deficient mice and human brain tissues were examined for corresponding pathology. Next, we silenced ABCD1 in cholinergic Sh-sy5y neurons to investigate its impact on neuronal function. Finally, we tested adeno-associated virus vector-mediated ABCD1 delivery to the brain in mice with adrenomyeloneuropathy. RESULTS ABCD1 is highly expressed in neurons located in the periaqueductal gray matter, basal forebrain and hypothalamus. In ABCD1-deficient mice (Abcd1-/y), these structures showed mild accumulations of α-synuclein. Similarly, healthy human controls had high expression of ABCD1 in deep gray nuclei, whereas X-ALD patients showed increased levels of phosphorylated tau, gliosis, and complement activation in those same regions, albeit not to the degree seen in neurodegenerative tauopathies. Silencing ABCD1 in Sh-sy5y neurons impaired expression of functional proteins and decreased acetylcholine levels, similar to observations in plasma of Abcd1-/y mice. Notably, hind limb clasping in Abcd1-/y mice was corrected through transduction of ABCD1 in basal forebrain neurons following intracerebroventricular gene delivery. INTERPRETATION Our study suggests that the basal forebrain-cortical cholinergic pathway may contribute to dysfunction in adrenomyeloneuropathy. Rescuing peroxisomal transport activity in basal forebrain neurons and supporting glial cells might represent a viable therapeutic strategy. ANN NEUROL 2024;95:442-458.
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Affiliation(s)
- Yi Gong
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston
| | - Fiza Laheji
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston
| | - Anna Berenson
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston
| | - Yedda Li
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston
| | - Ann Moser
- Peroxisome Disease Lab, Hugo W Moser Research Institute, Baltimore, MD, USA
| | - April Qian
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston
| | - Matthew Frosch
- Massachusetts General Hospital, Department of Neuropathology, Harvard Medical School, Boston
| | - Reza Sadjadi
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston
| | - Ryan Hahn
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston
| | - Casey A. Maguire
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston
| | - Florian Eichler
- Massachusetts General Hospital, Department of Neurology, Harvard Medical School, Boston
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Unveiling the Role of the Proton Gateway, Uncoupling Proteins (UCPs), in Cancer Cachexia. Cancers (Basel) 2023; 15:cancers15051407. [PMID: 36900198 PMCID: PMC10000250 DOI: 10.3390/cancers15051407] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 01/30/2023] [Accepted: 02/20/2023] [Indexed: 02/25/2023] Open
Abstract
Uncoupling proteins (UCPs) are identified as carriers of proton ions between the mitochondrial inner membrane and the mitochondrial matrix. ATP is mainly generated through oxidative phosphorylation in mitochondria. The proton gradient is generated across the inner mitochondrial membrane and the mitochondrial matrix, which facilitates a smooth transfer of electrons across ETC complexes. Until now, it was thought that the role of UCPs was to break the electron transport chain and thereby inhibit the synthesis of ATP. UCPs allow protons to pass from the inner mitochondrial membrane to the mitochondrial matrix and decrease the proton gradient across the membrane, which results in decreased ATP synthesis and increased production of heat by mitochondria. In recent years, the role of UCPs in other physiological processes has been deciphered. In this review, we first highlighted the different types of UCPs and their precise location across the body. Second, we summarized the role of UCPs in different diseases, mainly metabolic disorders such as obesity and diabetes, cardiovascular complications, cancer, wasting syndrome, neurodegenerative diseases, and kidney complications. Based on our findings, we conclude that UCPs play a major role in maintaining energy homeostasis, mitochondrial functions, ROS production, and apoptosis. Finally, our findings reveal that mitochondrial uncoupling by UCPs may treat many diseases, and extensive clinical studies are required to meet the unmet need of certain diseases.
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Mehramiz M, Porter T, Laws SM, Rainey-Smith SR. Sleep, Sirtuin 1 and Alzheimer's disease: A review. AGING BRAIN 2022; 2:100050. [PMID: 36908890 PMCID: PMC9997138 DOI: 10.1016/j.nbas.2022.100050] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 08/01/2022] [Accepted: 08/09/2022] [Indexed: 11/25/2022] Open
Abstract
Sleep plays a major role in brain health, and cognition. Disrupted sleep is a well-described symptom of Alzheimer's disease (AD). However, accumulating evidence suggests suboptimal sleep also increases AD risk. The deacetylase Sirtuin 1 (Sirt 1), encoded by the SIRT1 gene, impacts sleep via its relationship to wake-sleep neurotransmitters and somnogens. Evidence from animal and human studies supports a significant and complex relationship between sleep, Sirt 1/ SIRT1 and AD. Numerous hypotheses attempt to explain the critical impact of Sirt 1/ SIRT1 on wake- and sleep- promoting neurons, their related mechanisms and neurotransmitters. However, there is a paucity of studies assessing the interaction between sleep and Sirt 1/ SIRT1, as a principal component of sleep regulation, on AD pathology. In this review, we explore the potential association between Sirt 1/ SIRT1, sleep, and AD aetiology. Given sleep is a likely modifiable risk factor for AD, and recent studies suggest Sirt 1/ SIRT1 activation can be modulated by lifestyle or dietary approaches, further research in this area is required to explore its potential as a target for AD prevention and treatment.
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Affiliation(s)
- Mehrane Mehramiz
- Centre for Precision Health, Edith Cowan University, Joondalup, WA, Australia.,Collaborative Genomics and Translation Group, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Tenielle Porter
- Centre for Precision Health, Edith Cowan University, Joondalup, WA, Australia.,Collaborative Genomics and Translation Group, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA, Australia
| | - Simon M Laws
- Centre for Precision Health, Edith Cowan University, Joondalup, WA, Australia.,Collaborative Genomics and Translation Group, School of Medical and Health Sciences, Edith Cowan University, Joondalup, WA, Australia.,School of Pharmacy and Biomedical Sciences, Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Bentley, WA, Australia
| | - Stephanie R Rainey-Smith
- Centre for Healthy Ageing, Health Futures Institute, Murdoch University, Murdoch, WA, Australia.,Lifestyle Approaches Towards Cognitive Health Research Group, Murdoch University, Murdoch, WA, Australia.,Australian Alzheimer's Research Foundation (Ralph and Patricia Sarich Neuroscience Research Institute), Nedlands, WA, Australia.,Centre of Excellence for Alzheimer's Disease Research and Care, Edith Cowan University, Joondalup, WA, Australia.,School of Psychological Science, University of Western Australia, Crawley, WA, Australia
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4
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Mitochondrial Uncoupling Proteins (UCPs) as Key Modulators of ROS Homeostasis: A Crosstalk between Diabesity and Male Infertility? Antioxidants (Basel) 2021; 10:antiox10111746. [PMID: 34829617 PMCID: PMC8614977 DOI: 10.3390/antiox10111746] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2021] [Revised: 10/27/2021] [Accepted: 10/28/2021] [Indexed: 12/14/2022] Open
Abstract
Uncoupling proteins (UCPs) are transmembrane proteins members of the mitochondrial anion transporter family present in the mitochondrial inner membrane. Currently, six homologs have been identified (UCP1-6) in mammals, with ubiquitous tissue distribution and multiple physiological functions. UCPs are regulators of key events for cellular bioenergetic metabolism, such as membrane potential, metabolic efficiency, and energy dissipation also functioning as pivotal modulators of ROS production and general cellular redox state. UCPs can act as proton channels, leading to proton re-entry the mitochondrial matrix from the intermembrane space and thus collapsing the proton gradient and decreasing the membrane potential. Each homolog exhibits its specific functions, from thermogenesis to regulation of ROS production. The expression and function of UCPs are intimately linked to diabesity, with their dysregulation/dysfunction not only associated to diabesity onset, but also by exacerbating oxidative stress-related damage. Male infertility is one of the most overlooked diabesity-related comorbidities, where high oxidative stress takes a major role. In this review, we discuss in detail the expression and function of the different UCP homologs. In addition, the role of UCPs as key regulators of ROS production and redox homeostasis, as well as their influence on the pathophysiology of diabesity and potential role on diabesity-induced male infertility is debated.
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Keskin-Aktan A, Akbulut KG, Abdi S, Akbulut H. SIRT2 and FOXO3a expressions in the cerebral cortex and hippocampus of young and aged male rats: antioxidant and anti-apoptotic effects of melatonin. Biol Futur 2021; 73:71-85. [PMID: 34708398 DOI: 10.1007/s42977-021-00102-3] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 10/17/2021] [Indexed: 12/14/2022]
Abstract
Melatonin has antioxidant, anti-apoptotic and anti-aging effects in the brain. Sirtuin2 (SIRT2) accumulates in the central nervous system with aging, and its inhibition appears to be protective in aging and aging-related neurodegenerative diseases. Forkhead Box-class O3a (FOXO3a) transcription factor is one of the main targets of SIRT2, and SIRT2-mediated FOXO3a deacetylation is closely related to aging, oxidative stress, and apoptosis. This study aimed to investigate the effects of melatonin on SIRT2 and FOXO3a expressions in the cerebral cortex and hippocampus of aged rats. Young (3 months, n = 18) and aged (22 months, n = 18) male Wistar rats were divided into control (4% DMSO-PBS, sc, for 21 days), melatonin (10 mg/kg, sc, for 21 days) and salermide (1 mM; 25 μl/100 g bw, ip, for 21 days) groups. SIRT2, FOXO3a, Bcl-2, Bax and Bim expressions in the cerebral cortex and hippocampus were demonstrated by Western blotting. SIRT2 and FOXO3a protein levels were also measured by a sandwich ELISA method. Oxidative stress index (OSI) was calculated by measuring total oxidant status (TOS) and total antioxidant status (TAS). Aging increased SIRT2, FOXO3a, Bim (only in the cerebral cortex), Bax (only in the hippocampus), TOS, and OSI, while decreasing Bcl-2, Bcl-2/Bax and TAS in both brain regions. Melatonin decreased SIRT2, FOXO3a, oxidative stress parameters and pro-apoptotic proteins, while increasing TAS, Bcl-2 and Bcl-2/Bax, more specifically in the hippocampus of the aged brain. Our results indicate that inhibition of SIRT2 and FOXO3a expressions appears to be involved in the protective effects of melatonin in the hippocampus of aged rats.
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Affiliation(s)
- Arzu Keskin-Aktan
- Department of Physiology, School of Medicine, Afyonkarahisar Health Sciences University, Afyonkarahisar, 03200, Turkey.
| | | | - Samira Abdi
- Department of Basic Oncology, Institute of Cancer Research, Ankara University, Ankara, Turkey
| | - Hakan Akbulut
- Department of Basic Oncology, Institute of Cancer Research, Ankara University, Ankara, Turkey
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Lin JY, Kuo WW, Baskaran R, Kuo CH, Chen YA, Chen WST, Ho TJ, Day CH, Mahalakshmi B, Huang CY. Swimming exercise stimulates IGF1/ PI3K/Akt and AMPK/SIRT1/PGC1α survival signaling to suppress apoptosis and inflammation in aging hippocampus. Aging (Albany NY) 2020; 12:6852-6864. [PMID: 32320382 PMCID: PMC7202519 DOI: 10.18632/aging.103046] [Citation(s) in RCA: 75] [Impact Index Per Article: 18.8] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Accepted: 03/09/2020] [Indexed: 12/22/2022]
Abstract
Hippocampus is one of the most vulnerable brain regions in terms of age-related pathological change. Exercise is presumed to delay the aging process and promote health because it seems to improve the function of most of the aging mechanisms. The purpose of this study is to evaluate the effects of swimming exercise training on brain inflammation, apoptotic and survival pathways in the hippocampus of D-galactose-induced aging in SD rats. The rats were allocated to the following groups: (1) control; (2) swimming exercise; (3) induced-aging by injecting D-galactose; (4) induced-aging rats with swimming exercise. The longevity-related AMPK/SIRT1/PGC-1α signaling pathway and brain IGF1/PI3K/Akt survival pathway were significantly reduced in D-galactose-induced aging group compared to non-aging control group and increased after exercise training. The inflammation pathway markers were over-expressed in induced-aging hippocampus, exercise significantly inhibited the inflammatory signaling activity. Fas-dependent and mitochondrial-dependent apoptotic pathways were significantly increased in the induced-aging group relative to the control group whereas they were decreased in the aging-exercise group. This study demonstrated that swimming exercise not only reduced aging-induced brain apoptosis and inflammatory signaling activity, but also enhanced the survival pathways in the hippocampus, which provides one of the new beneficial effects for exercise training in aging brain.
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Affiliation(s)
- Jing-Ying Lin
- Department of Medical Imaging and Radiological Science, Central Taiwan University of Science and Technology, Taichung, Taiwan
| | - Wei-Wen Kuo
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan
| | - Rathinasamy Baskaran
- Department of Bioinformatics and Medical Engineering, Asia University, Taichung, Taiwan
| | - Chia-Hua Kuo
- Laboratory of Exercise Biochemistry, University of Taipei, Taipei, Taiwan
| | - Yun-An Chen
- Department of Biological Science and Technology, China Medical University, Taichung, Taiwan
| | - William Shao-Tsu Chen
- Division of Addictive Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Tzu Chi University, Hualien, Taiwan
| | - Tsung-Jung Ho
- Department of Chinese Medicine, Hualien Tzu Chi Hospital, Buddhist Tzu Chi Medical Foundation, Tzu Chi University, Hualien, Taiwan
| | | | - B Mahalakshmi
- Institute of Research and Development, Duy Tan University, Da Nang, Vietnam
| | - Chih-Yang Huang
- Graduate Institute of Biomedical Sciences, China Medical University, Taichung, Taiwan.,Center of General Education, Buddhist Tzu Chi Medical Foundation, Tzu Chi University of Science and Technology, Hualien, Taiwan.,Department of Medical Research, China Medical University Hospital, China Medical University, Taichung, Taiwan.,Department of Biotechnology, Asia University, Taichung, Taiwan
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7
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Elibol B, Kilic U. High Levels of SIRT1 Expression as a Protective Mechanism Against Disease-Related Conditions. Front Endocrinol (Lausanne) 2018; 9:614. [PMID: 30374331 PMCID: PMC6196295 DOI: 10.3389/fendo.2018.00614] [Citation(s) in RCA: 93] [Impact Index Per Article: 15.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Accepted: 09/27/2018] [Indexed: 01/11/2023] Open
Abstract
SIRT1 protein, a member of Silent Information Regulator 2 (Sir2) protein family, have gained considerable attention as epigenetic regulators for a great area in the human physiology. Changes in sirtuin expression are critical in several diseases, including metabolic syndrome, cardiovascular diseases, cancer and neurodegeneration. Here, we provide an overview of the association of the increasing level of SIRT1 protein for regulating some disease related conditions such as obesity, cardiovascular diseases and neurodegeneration. This review also provides a detailed molecular understanding of the interaction of the some basic molecules with increasing SIRT1 levels rather than reduction of the SIRT1 expression. In this context, the current approaches to enhancing the expression of SIRT1 points the importance of epigenetics in several age-related diseases to provide a healthy aging by developing novel therapies which can prevent or damp the progression of some diseases.
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Affiliation(s)
- Birsen Elibol
- Department of Medical Biology, Faculty of Medicine, Bezmialem Vakif University, Istanbul, Turkey
| | - Ulkan Kilic
- Department of Medical Biology, Faculty of Medicine, University of Health Sciences, Istanbul, Turkey
- *Correspondence: Ulkan Kilic
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8
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Song J, Kim J. Role of Sirtuins in Linking Metabolic Syndrome with Depression. Front Cell Neurosci 2016; 10:86. [PMID: 27065808 PMCID: PMC4814520 DOI: 10.3389/fncel.2016.00086] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 03/21/2016] [Indexed: 12/20/2022] Open
Abstract
Depression is now widely regarded as a common disabling disorder that affects negatively the social functioning all over the world. Depression is associated with diverse phenomenon in brain such as neuroinflammation, synaptic dysfunction, and cognitive deficit. Recent studies reported that depression occurs by various metabolic changes, leading to metabolic syndrome. Sirtuins (SIRTs) are NAD+-dependent class III histone deacetylases, known to regulate diverse biological mechanism such as longevity, genomic stability, and inflammation. The modulation of sirtuin activity has been highlighted as a promising approach to reduce neurodegenerative processes. In this review, we summarize the recent discoveries regarding the potential relationship between SIRTs and depression caused by metabolic disorders (Mets). Ultimately, we suggest the possibility that SIRTs will be novel targets to alleviate neuropathogenesis induced by depression.
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Affiliation(s)
- Juhyun Song
- Department of Biomedical Engineering, Dongguk University Seoul, South Korea
| | - Jongpil Kim
- Department of Biomedical Engineering, Dongguk University Seoul, South Korea
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9
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Szafranski K, Abraham KJ, Mekhail K. Non-coding RNA in neural function, disease, and aging. Front Genet 2015; 6:87. [PMID: 25806046 PMCID: PMC4353379 DOI: 10.3389/fgene.2015.00087] [Citation(s) in RCA: 67] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/01/2014] [Accepted: 02/18/2015] [Indexed: 12/03/2022] Open
Abstract
Declining brain and neurobiological function is arguably one of the most common features of human aging. The study of conserved aging processes as well as the characterization of various neurodegenerative diseases using different genetic models such as yeast, fly, mouse, and human systems is uncovering links to non-coding RNAs. These links implicate a variety of RNA-regulatory processes, including microRNA function, paraspeckle formation, RNA–DNA hybrid regulation, nucleolar RNAs and toxic RNA clearance, amongst others. Here we highlight these connections and reveal over-arching themes or questions related to recently appreciated roles of non-coding RNA in neural function and dysfunction across lifespan.
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Affiliation(s)
- Kirk Szafranski
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Karan J Abraham
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto Toronto, ON, Canada
| | - Karim Mekhail
- Department of Laboratory Medicine and Pathobiology, Faculty of Medicine, University of Toronto Toronto, ON, Canada ; Canada Research Chairs Program, Faculty of Medicine, University of Toronto Toronto, ON, Canada
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10
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Yu P, McKinney EC, Kandasamy MM, Albert AL, Meagher RB. Characterization of brain cell nuclei with decondensed chromatin. Dev Neurobiol 2014; 75:738-56. [PMID: 25369517 DOI: 10.1002/dneu.22245] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2014] [Revised: 10/22/2014] [Accepted: 10/30/2014] [Indexed: 12/14/2022]
Abstract
Although multipotent cell types have enlarged nuclei with decondensed chromatin, this property has not been exploited to enhance the characterization of neural progenitor cell (NPC) populations in the brain. We found that mouse brain cell nuclei that expressed exceptionally high levels of the pan neuronal marker NeuN/FOX3 (NeuN-High) had decondensed chromatin relative to most NeuN-Low or NeuN-Neg (negative) nuclei. Purified NeuN-High nuclei expressed significantly higher levels of transcripts encoding markers of neurogenesis, neuroplasticity, and learning and memory (ARC, BDNF, ERG1, HOMER1, NFL/NEF1, SYT1), subunits of chromatin modifying machinery (SIRT1, HDAC1, HDAC2, HDAC11, KAT2B, KAT3A, KAT3B, KAT5, DMNT1, DNMT3A, Gadd45a, Gadd45b) and markers of NPC and cell cycle activity (BRN2, FOXG1, KLF4, c-MYC, OCT4, PCNA, SHH, SOX2) relative to neuronal NeuN-Low or to mostly non-neuronal NeuN-Neg nuclei. NeuN-High nuclei expressed higher levels of HDAC1, 2, 4, and 5 proteins. The cortex, hippocampus, hypothalamus, thalamus, and nucleus accumbens contained high percentages of large decondensed NeuN-High nuclei, while the cerebellum, and pons contained very few. NeuN-High nuclei have the properties consistent with their being derived from extremely active neurons with elevated rates of chromatin modification and/or NPC-like cells with multilineage developmental potential. The further analysis of decondensed neural cell nuclei should provide novel insights into neurobiology and neurodegenerative disease.
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Affiliation(s)
- Ping Yu
- Department of Genetics, University of Georgia, Davison Life Sciences Building, Athens, Georgia, 30602
| | - Elizabeth C McKinney
- Department of Genetics, University of Georgia, Davison Life Sciences Building, Athens, Georgia, 30602
| | - Muthugapatti M Kandasamy
- Department of Genetics, University of Georgia, Davison Life Sciences Building, Athens, Georgia, 30602
| | | | - Richard B Meagher
- Department of Genetics, University of Georgia, Davison Life Sciences Building, Athens, Georgia, 30602
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11
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Perreten Lambert H, Zenger M, Azarias G, Chatton JY, Magistretti PJ, Lengacher S. Control of mitochondrial pH by uncoupling protein 4 in astrocytes promotes neuronal survival. J Biol Chem 2014; 289:31014-28. [PMID: 25237189 DOI: 10.1074/jbc.m114.570879] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
Brain activity is energetically costly and requires a steady and highly regulated flow of energy equivalents between neural cells. It is believed that a substantial share of cerebral glucose, the major source of energy of the brain, will preferentially be metabolized in astrocytes via aerobic glycolysis. The aim of this study was to evaluate whether uncoupling proteins (UCPs), located in the inner membrane of mitochondria, play a role in setting up the metabolic response pattern of astrocytes. UCPs are believed to mediate the transmembrane transfer of protons, resulting in the uncoupling of oxidative phosphorylation from ATP production. UCPs are therefore potentially important regulators of energy fluxes. The main UCP isoforms expressed in the brain are UCP2, UCP4, and UCP5. We examined in particular the role of UCP4 in neuron-astrocyte metabolic coupling and measured a range of functional metabolic parameters including mitochondrial electrical potential and pH, reactive oxygen species production, NAD/NADH ratio, ATP/ADP ratio, CO2 and lactate production, and oxygen consumption rate. In brief, we found that UCP4 regulates the intramitochondrial pH of astrocytes, which acidifies as a consequence of glutamate uptake, with the main consequence of reducing efficiency of mitochondrial ATP production. The diminished ATP production is effectively compensated by enhancement of glycolysis. This nonoxidative production of energy is not associated with deleterious H2O2 production. We show that astrocytes expressing more UCP4 produced more lactate, which is used as an energy source by neurons, and had the ability to enhance neuronal survival.
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Affiliation(s)
- Hélène Perreten Lambert
- From the School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Manuel Zenger
- From the School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland
| | - Guillaume Azarias
- the Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland, and
| | - Jean-Yves Chatton
- the Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, Switzerland, and
| | - Pierre J Magistretti
- From the School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland, the King Abdullah University of Science and Technology, Thuwal 23955-6900, Kingdom of Saudi Arabia, the Center for Psychiatric Neuroscience, 1008 Prilly-Lausanne, Switzerland
| | - Sylvain Lengacher
- From the School of Life Sciences, Brain Mind Institute, Ecole Polytechnique Fédérale de Lausanne, 1015 Lausanne, Switzerland, the Center for Psychiatric Neuroscience, 1008 Prilly-Lausanne, Switzerland
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Seo DB, Jeong HW, Lee SJ, Lee SJ. Coumestrol induces mitochondrial biogenesis by activating Sirt1 in cultured skeletal muscle cells. JOURNAL OF AGRICULTURAL AND FOOD CHEMISTRY 2014; 62:4298-4305. [PMID: 24712520 DOI: 10.1021/jf404882w] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/03/2023]
Abstract
The mitochondrion is a central organelle in cellular energy homeostasis; thus, reduced mitochondrial activity has been associated with aging and metabolic disorders. This paper provides biological evidence that coumestrol, which is a natural isoflavone, activates mitochondrial biogenesis. In cultured myocytes, coumestrol activated the silent information regulator two ortholog 1 (Sirt1) through the elevation of the intracellular NAD(+)/NADH ratio. Coumestrol also increased the mitochondrial contents and induced the expression of key proteins in the mitochondrial electron transfer chain in cultured myocytes. A Sirt1 inhibitor and Sirt1-targeting siRNAs abolished the effect of coumestrol on mitochondrial biogenesis. Similar to an increase in mitochondrial content, coumestrol improved myocyte function with increased ATP concentration. Taken together, the data suggest that coumestrol is a novel inducer of mitochondrial biogenesis through the activation of Sirt1.
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Affiliation(s)
- Dae-Bang Seo
- College of Life and Environmental Sciences, Division of Food Science, Korea University , Seoul 136-713, Republic of Korea
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13
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Du G, Song Y, Zhang T, Ma L, Bian N, Chen X, Feng J, Chang Q, Li Z. Simvastatin attenuates TNF‑α‑induced apoptosis in endothelial progenitor cells via the upregulation of SIRT1. Int J Mol Med 2014; 34:177-82. [PMID: 24718722 DOI: 10.3892/ijmm.2014.1740] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Accepted: 04/01/2014] [Indexed: 01/30/2023] Open
Abstract
Endothelial progenitor cells (EPCs) originate from the bone marrow and can be classified as either early or late EPCs. The focus of this study was on late EPCs, as they play an important role in angiogenesis and vascular proliferation. Evidence suggests that inflammatory and oxidative changes can increase EPC apoptosis. Of note, tumor necrosis factor-α (TNF-α) is a contributing risk factor to the development of atherosclerosis and plays a key role as both an inflammatory mediator and an inducer of apoptosis in endothelial cells. Additionally, a member of the sirtuin family, silent information regulator type-1 (SIRT1), promotes cell survival by repressing p53- and non-p53-dependent apoptosis in response to DNA damage and oxidative stress. Statins have also been shown to play a key role in the prevention of endothelial apoptosis and senescence via their lipid-lowering and anti-inflammatory actions. However, there is little evidence that statins themselves attenuate EPC apoptosis induced by TNF-α. The aim of this study was to demonstrate the effectiveness of one of the most commonly used statins, simvastatin, on decreasing TNF-α-induced apoptosis in EPCs. The results indicated that SIRT1 protein expression was decreased by TNF-α in a time- and dose-dependent manner and that while TNF-α caused a marked increase in the percentage of apoptotic EPCs, application of simvastatin decreased this percentage. A high concentration of simvastatin promoted the expression of SIRT1 and increased the proliferation of EPCs. In conclusion, findings of this study showed that simvastatin is crucial in counteracting the TNF-α-induced apoptosis of EPCs and that this protection may involve the actions of SIRT1.
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Affiliation(s)
- Gang Du
- Department of Internal Medicine, The First Affiliated Hospital of Jinan University, Guangzhou 510630, P.R. China
| | - Yunlin Song
- Intensive Care Unit, The First Affiliated Hospital of Xinjiang Medical University, Urumqi 830011, P.R. China
| | - Tao Zhang
- Department of Internal Medicine, The First Affiliated Hospital of Jinan University, Guangzhou 510630, P.R. China
| | - Long Ma
- Intensive Care Unit, The First Affiliated Hospital of Xinjiang Medical University, Urumqi 830011, P.R. China
| | - Ning Bian
- Department of Internal Medicine, The First Affiliated Hospital of Jinan University, Guangzhou 510630, P.R. China
| | - Xiaoming Chen
- Department of Internal Medicine, The First Affiliated Hospital of Jinan University, Guangzhou 510630, P.R. China
| | - Jianyi Feng
- Department of Internal Medicine, The First Affiliated Hospital of Jinan University, Guangzhou 510630, P.R. China
| | - Qing Chang
- Department of Histology and Embryology, Medical College of Jinan University, Guangzhou 510632, P.R. China
| | - Zicheng Li
- Department of Internal Medicine, The First Affiliated Hospital of Jinan University, Guangzhou 510630, P.R. China
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14
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Huang R, Wang ZR, Sun Y, Zhang G, Lu YP. [Mechanism of Nampt gene expression regulation]. YI CHUAN = HEREDITAS 2013; 34:1561-9. [PMID: 23262103 DOI: 10.3724/sp.j.1005.2012.01561] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Nicotinamide phosphoribosyltransferase (NAMPT), also known as pre-B cell colony-enhancing factor (PBEF) or visfatin, is a crucial rate-limiting enzyme of NAD biosynthetic pathway. It may affect the metabolism, inflammatory response, cell proliferation, differentiation, and apoptosis, especially the aging and other physiological progresses through regulating NAD biosynthesis and nonenzyme routes in the organisms and cells. This review mainly focuses on recent progresses in the expression modulation and feedback regulation of Nampt gene.
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Affiliation(s)
- Rui Huang
- College of Life, Anhui Normal University, Wuhu 241000, China.
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15
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Morris BJ. Seven sirtuins for seven deadly diseases of aging. Free Radic Biol Med 2013; 56:133-71. [PMID: 23104101 DOI: 10.1016/j.freeradbiomed.2012.10.525] [Citation(s) in RCA: 280] [Impact Index Per Article: 25.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/25/2012] [Revised: 08/31/2012] [Accepted: 10/05/2012] [Indexed: 12/14/2022]
Abstract
Sirtuins are a class of NAD(+)-dependent deacetylases having beneficial health effects. This extensive review describes the numerous intracellular actions of the seven mammalian sirtuins, their protein targets, intracellular localization, the pathways they modulate, and their role in common diseases of aging. Selective pharmacological targeting of sirtuins is of current interest in helping to alleviate global disease burden. Since all sirtuins are activated by NAD(+), strategies that boost NAD(+) in cells are of interest. While most is known about SIRT1, the functions of the six other sirtuins are now emerging. Best known is the involvement of sirtuins in helping cells adapt energy output to match energy requirements. SIRT1 and some of the other sirtuins enhance fat metabolism and modulate mitochondrial respiration to optimize energy harvesting. The AMP kinase/SIRT1-PGC-1α-PPAR axis and mitochondrial sirtuins appear pivotal to maintaining mitochondrial function. Downregulation with aging explains much of the pathophysiology that accumulates with aging. Posttranslational modifications of sirtuins and their substrates affect specificity. Although SIRT1 activation seems not to affect life span, activation of some of the other sirtuins might. Since sirtuins are crucial to pathways that counter the decline in health that accompanies aging, pharmacological agents that boost sirtuin activity have clinical potential in treatment of diabetes, cardiovascular disease, dementia, osteoporosis, arthritis, and other conditions. In cancer, however, SIRT1 inhibitors could have therapeutic value. Nutraceuticals such as resveratrol have a multiplicity of actions besides sirtuin activation. Their net health benefit and relative safety may have originated from the ability of animals to survive environmental changes by utilizing these stress resistance chemicals in the diet during evolution. Each sirtuin forms a key hub to the intracellular pathways affected.
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Affiliation(s)
- Brian J Morris
- Basic & Clinical Genomics Laboratory, School of Medical Sciences and Bosch Institute, Building F13, University of Sydney, NSW 2006, Australia.
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Ramsden DB, Ho PW, Ho JW, Liu H, So DH, Tse H, Chan K, Ho S. Human neuronal uncoupling proteins 4 and 5 (UCP4 and UCP5): structural properties, regulation, and physiological role in protection against oxidative stress and mitochondrial dysfunction. Brain Behav 2012; 2:468-78. [PMID: 22950050 PMCID: PMC3432969 DOI: 10.1002/brb3.55] [Citation(s) in RCA: 92] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/31/2011] [Revised: 03/07/2012] [Accepted: 03/09/2012] [Indexed: 01/07/2023] Open
Abstract
Uncoupling proteins (UCPs) belong to a large family of mitochondrial solute carriers 25 (SLC25s) localized at the inner mitochondrial membrane. UCPs transport protons directly from the intermembrane space to the matrix. Of five structural homologues (UCP1 to 5), UCP4 and 5 are principally expressed in the central nervous system (CNS). Neurons derived their energy in the form of ATP that is generated through oxidative phosphorylation carried out by five multiprotein complexes (Complexes I-V) embedded in the inner mitochondrial membrane. In oxidative phosphorylation, the flow of electrons generated by the oxidation of substrates through the electron transport chain to molecular oxygen at Complex IV leads to the transport of protons from the matrix to the intermembrane space by Complex I, III, and IV. This movement of protons to the intermembrane space generates a proton gradient (mitochondrial membrane potential; MMP) across the inner membrane. Complex V (ATP synthase) uses this MMP to drive the conversion of ADP to ATP. Some electrons escape to oxygen-forming harmful reactive oxygen species (ROS). Proton leakage back to the matrix which bypasses Complex V resulting in a major reduction in ROS formation while having a minimal effect on MMP and hence, ATP synthesis; a process termed "mild uncoupling." UCPs act to promote this proton leakage as means to prevent excessive build up of MMP and ROS formation. In this review, we discuss the structure and function of mitochondrial UCPs 4 and 5 and factors influencing their expression. Hypotheses concerning the evolution of the two proteins are examined. The protective mechanisms of the two proteins against neurotoxins and their possible role in regulating intracellular calcium movement, particularly with regard to the pathogenesis of Parkinson's disease are discussed.
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Affiliation(s)
- David B. Ramsden
- School of Medicine and School of Biosciences, University of Birmingham, United Kingdom
| | - Philip W.‐L. Ho
- Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, PR China
- Research Centre of Heart, Brain, Hormone and Healthy Aging (HBHA), University of Hong Kong, Hong Kong, PR China
| | - Jessica W.‐M. Ho
- Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, PR China
| | - Hui‐Fang Liu
- Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, PR China
| | - Danny H.‐F. So
- Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, PR China
| | - Ho‐Man Tse
- Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, PR China
| | - Koon‐Ho Chan
- Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, PR China
- Research Centre of Heart, Brain, Hormone and Healthy Aging (HBHA), University of Hong Kong, Hong Kong, PR China
| | - Shu‐Leong Ho
- Division of Neurology, Department of Medicine, University of Hong Kong, Hong Kong, PR China
- Research Centre of Heart, Brain, Hormone and Healthy Aging (HBHA), University of Hong Kong, Hong Kong, PR China
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Abstract
PURPOSE OF REVIEW Sirtuins are a family of enzymes highly conserved in evolution and involved in mechanisms known to promote healthy ageing and longevity. This review aims to discuss recent advances in understanding the role of sirtuins, in particular mammalian SIRT1, in promoting longevity and its potential molecular basis for neuroprotection against cognitive ageing and Alzheimer's disease pathology. RECENT FINDINGS Accumulative increase in oxidative stress during ageing has been shown to decrease SIRT1 activity in catabolic tissue, possibly by direct inactivation by reactive oxygen. SIRT1 overexpression prevents oxidative stress-induced apoptosis and increases resistance to oxidative stress through regulation of the FOXO family of forkhead transcription factors. In addition, resveratrol strongly stimulates SIRT1 deacetylase activity in a dose-dependent manner by increasing its binding affinity to both the acetylated substrate and NAD(+). Recently, SIRT1 has been shown to affect amyloid production through its influence over the ADAM10 gene. Upregulation of SIRT1 can also induce the Notch pathway and inhibit mTOR signalling. SUMMARY Recent studies have revealed some of the mechanisms and pathways that are associated with the neuroprotective effects of SIRT1.
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