51
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Valor LM, Guiretti D. What's wrong with epigenetics in Huntington's disease? Neuropharmacology 2013; 80:103-14. [PMID: 24184315 DOI: 10.1016/j.neuropharm.2013.10.025] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/29/2013] [Revised: 10/16/2013] [Accepted: 10/21/2013] [Indexed: 12/15/2022]
Abstract
Huntington's disease (HD) can be considered the paradigm of epigenetic dysregulation in neurodegenerative disorders. In this review, we attempted to compile the evidence that indicates, on the one hand, that several epigenetic marks (histone acetylation, methylation, ubiquitylation, phosphorylation and DNA modifications) are altered in multiple models and in postmortem patient samples, and on the other hand, that pharmacological treatments aimed to reverse such alterations have beneficial effects on HD phenotypic and biochemical traits. However, the working hypotheses regarding the biological significance of epigenetic dysregulation in this disease and the mechanisms of action of the tested ameliorative strategies need to be refined. Understanding the complexity of the epigenetics in HD will provide useful insights to examine the role of epigenetic dysregulation in other neuropathologies, such as Alzheimer's or Parkinson's diseases.
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Affiliation(s)
- Luis M Valor
- Instituto de Neurociencias de Alicante (Universidad Miguel Hernández, Consejo Superior de Investigaciones Científicas), Av. Santiago Ramón y Cajal s/n, Sant Joan d'Alacant, 03550 Alicante, Spain.
| | - Deisy Guiretti
- Instituto de Neurociencias de Alicante (Universidad Miguel Hernández, Consejo Superior de Investigaciones Científicas), Av. Santiago Ramón y Cajal s/n, Sant Joan d'Alacant, 03550 Alicante, Spain
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52
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Chaturvedi RK, Flint Beal M. Mitochondrial diseases of the brain. Free Radic Biol Med 2013; 63:1-29. [PMID: 23567191 DOI: 10.1016/j.freeradbiomed.2013.03.018] [Citation(s) in RCA: 329] [Impact Index Per Article: 27.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/22/2011] [Revised: 03/21/2013] [Accepted: 03/22/2013] [Indexed: 12/13/2022]
Abstract
Neurodegenerative disorders are debilitating diseases of the brain, characterized by behavioral, motor and cognitive impairments. Ample evidence underpins mitochondrial dysfunction as a central causal factor in the pathogenesis of neurodegenerative disorders including Parkinson's disease, Huntington's disease, Alzheimer's disease, Amyotrophic lateral sclerosis, Friedreich's ataxia and Charcot-Marie-Tooth disease. In this review, we discuss the role of mitochondrial dysfunction such as bioenergetics defects, mitochondrial DNA mutations, gene mutations, altered mitochondrial dynamics (mitochondrial fusion/fission, morphology, size, transport/trafficking, and movement), impaired transcription and the association of mutated proteins with mitochondria in these diseases. We highlight the therapeutic role of mitochondrial bioenergetic agents in toxin and in cellular and genetic animal models of neurodegenerative disorders. We also discuss clinical trials of bioenergetics agents in neurodegenerative disorders. Lastly, we shed light on PGC-1α, TORC-1, AMP kinase, Nrf2-ARE, and Sirtuins as novel therapeutic targets for neurodegenerative disorders.
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Affiliation(s)
- Rajnish K Chaturvedi
- CSIR-Indian Institute of Toxicology Research, 80 MG Marg, Lucknow 226001, India.
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53
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Guedes-Dias P, Oliveira JM. Lysine deacetylases and mitochondrial dynamics in neurodegeneration. Biochim Biophys Acta Mol Basis Dis 2013; 1832:1345-59. [DOI: 10.1016/j.bbadis.2013.04.005] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/30/2012] [Revised: 03/30/2013] [Accepted: 04/02/2013] [Indexed: 11/28/2022]
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54
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Im AR, Kim YH, Uddin MR, Chae SW, Lee HW, Jung WS, Kim YH, Kang BJ, Kim YS, Lee MY. Protection from antimycin A-induced mitochondrial dysfunction by Nelumbo nucifera seed extracts. ENVIRONMENTAL TOXICOLOGY AND PHARMACOLOGY 2013; 36:19-29. [PMID: 23542413 DOI: 10.1016/j.etap.2013.02.015] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/15/2012] [Revised: 02/07/2013] [Accepted: 02/16/2013] [Indexed: 06/02/2023]
Abstract
Antimycin A (AMA) damages the mitochondria through inhibition of mitochondrial electron transport. In this study, exposure of L6 rat skeletal muscle cells to AMA induced a decrease in ATP content, followed by a decrease in mitochondrial membrane potential, leading to apoptosis. We evaluated the protective effects of water and ethanol extracts of Nelumbo nucifera seeds on L6 cells with AMA-induced oxidative stress. We found that the extracts reduced cellular apoptosis; preserved the mitochondrial membrane potential; protected mitochondrial ATP production; inhibited p53, Bax, and caspase 3 activities; and induced Bcl-2 production. Our results suggested that AMA induced apoptosis in L6 cells via impairment of mitochondrial function. N. nucifera extracts protected the cells from this mitochondria-mediated cell death.
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Affiliation(s)
- A-Rang Im
- Korea Institute of Oriental Medicine, Daejeon 305-811, South Korea
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55
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Fan J, Alsarraf O, Dahrouj M, Platt KA, Chou CJ, Rice DS, Crosson CE. Inhibition of HDAC2 protects the retina from ischemic injury. Invest Ophthalmol Vis Sci 2013; 54:4072-80. [PMID: 23696608 DOI: 10.1167/iovs.12-11529] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/31/2023] Open
Abstract
PURPOSE Protein acetylation is an essential mechanism in regulating transcriptional and inflammatory events. Studies have shown that nonselective histone deacetylase (HDAC) inhibitors can protect the retina from ischemic injury in rats. However, the role of specific HDAC isoforms in retinal degenerative processes remains obscure. The purpose of this study was to investigate the role of HDAC2 isoform in a mouse model of ischemic retinal injury. METHODS Localization of HDAC2 in mice retinas was evaluated by immunohistochemical analyses. To investigate whether selective reduction in HDAC2 activity can protect the retina from ischemic injury, Hdac2⁺/⁻ mice were utilized. Electroretinographic (ERG) and morphometric analyses were used to assess retinal function and morphology. RESULTS Our results demonstrated that HDAC2 is primarily localized in nuclei in inner nuclear and retinal ganglion cell layers, and HDAC2 activity accounted for approximately 35% of the total activities of HDAC1, 2, 3, and 6 in the retina. In wild-type mice, ERG a- and b-waves from ischemic eyes were significantly reduced when compared to pre-ischemia baseline values. Morphometric examination of these eyes revealed significant degeneration of inner retinal layers. In Hdac2⁺/⁻ mice, ERG a- and b-waves from ischemic eyes were significantly greater than those measured in ischemic eyes from wild-type mice. Morphologic measurements demonstrated that Hdac2⁺/⁻ mice exhibit significantly less retinal degeneration than wild-type mice. CONCLUSIONS This study demonstrated that suppressing HDAC2 expression can effectively reduce ischemic retinal injury. Our results support the idea that the development of selective HDAC2 inhibitors may provide an efficacious treatment for ischemic retinal injury.
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Affiliation(s)
- Jie Fan
- Storm Eye Institute, Department of Ophthalmology, Medical University of South Carolina, Charleston, South Carolina 29425, USA.
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56
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Silva AC, Almeida S, Laço M, Duarte AI, Domingues J, Oliveira CR, Januário C, Rego AC. Mitochondrial respiratory chain complex activity and bioenergetic alterations in human platelets derived from pre-symptomatic and symptomatic Huntington's disease carriers. Mitochondrion 2013; 13:801-9. [PMID: 23707479 DOI: 10.1016/j.mito.2013.05.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2012] [Revised: 04/17/2013] [Accepted: 05/07/2013] [Indexed: 01/14/2023]
Abstract
Mitochondrial dysfunction has been implicated in Huntington's disease (HD) pathogenesis. We analyzed the activity of mitochondrial complexes (Cx) I-IV, protein levels of selected Cx subunits and adenine nucleotides in platelet mitochondria from pre-symptomatic versus symptomatic HD human carriers and age-matched control individuals. Mitochondrial platelets exhibited reduced activity of citrate synthase in pre-symptomatic and Cx-I in pre-symptomatic and symptomatic HD carriers. Positive correlation between Cx activity and protein subunits was observed for Cx-I in symptomatic HD patient's mitochondria. Moreover, AMP increased in mitochondria from pre-symptomatic HD carriers. Results highlight mitochondrial changes occurring before the onset of HD clinical symptoms.
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Affiliation(s)
- Ana C Silva
- CNC - Center for Neuroscience and Cell Biology, University of Coimbra, Portugal
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57
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Chaturvedi RK, Beal MF. Mitochondria targeted therapeutic approaches in Parkinson's and Huntington's diseases. Mol Cell Neurosci 2012; 55:101-14. [PMID: 23220289 DOI: 10.1016/j.mcn.2012.11.011] [Citation(s) in RCA: 105] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2012] [Revised: 11/20/2012] [Accepted: 11/27/2012] [Indexed: 12/18/2022] Open
Abstract
Substantial evidence from both genetic and toxin induced animal and cellular models and postmortem human brain tissue indicates that mitochondrial dysfunction plays a central role in pathophysiology of the neurodegenerative disorders including Parkinson's disease (PD), and Huntington's disease (HD). This review discusses the emerging understanding of the role of mitochondrial dysfunction including bioenergetics defects, mitochondrial DNA mutations, familial nuclear DNA mutations, altered mitochondrial fusion/fission and morphology, mitochondrial transport/trafficking, altered transcription and increased interaction of pathogenic proteins with mitochondria in the pathogenesis of PD and HD. This review recapitulates some of the key therapeutic strategies applied to surmount mitochondrial dysfunction in these debilitating disorders. We discuss the therapeutic role of mitochondrial bioenergetic agents such as creatine, Coenzyme-Q10, mitochondrial targeted antioxidants and peptides, the SIRT1 activator resveratrol, and the pan-PPAR agonist bezafibrate in toxin and genetic cellular and animal models of PD and HD. We also summarize the phase II-III clinical trials conducted using some of these agents. Lastly, we discuss PGC-1α, TORC and Sirtuins as potential therapeutic targets for mitochondrial dysfunction in neurodegenerative disorders. This article is part of a Special Issue entitled 'Mitochondrial function and dysfunction in neurodegeneration'.
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Affiliation(s)
- Rajnish K Chaturvedi
- Developmental Toxicology Division, Systems Toxicology Group, CSIR-Indian Institute of Toxicology Research (CSIR-IITR), 80 MG Marg, Lucknow 226001, India.
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58
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Ribeiro M, Rosenstock TR, Cunha-Oliveira T, Ferreira IL, Oliveira CR, Rego AC. Glutathione redox cycle dysregulation in Huntington's disease knock-in striatal cells. Free Radic Biol Med 2012; 53:1857-67. [PMID: 22982598 DOI: 10.1016/j.freeradbiomed.2012.09.004] [Citation(s) in RCA: 53] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/23/2012] [Revised: 09/04/2012] [Accepted: 09/06/2012] [Indexed: 01/06/2023]
Abstract
Huntington's disease (HD) is a CAG repeat disorder affecting the HD gene, which encodes for huntingtin (Htt) and is characterized by prominent cell death in the striatum. Oxidative stress was previously implicated in HD neurodegeneration, but the role of the major endogenous antioxidant system, the glutathione redox cycle, has been less studied following expression of full-length mutant Htt (FL-mHtt). Thus, in this work we analyzed the glutathione system in striatal cells derived from HD knock-in mice expressing mutant Htt versus wild-type cells. Mutant cells showed increased intracellular reactive oxygen species (ROS) and caspase-3 activity, which were significantly prevented following treatment with glutathione ethyl ester. Interestingly, mutant cells exhibited an increase in intracellular levels of both reduced and oxidized forms of glutathione, and enhanced activities of glutathione peroxidase (GPx) and glutathione reductase (GRed). Furthermore, glutathione-S-transferase (GST) and γ-glutamyl transpeptidase (γ-GT) activities were also increased in mutant cells. Nevertheless, glutamate-cysteine ligase (GCL) and glutathione synthetase (GS) activities and levels of GCL catalytic subunit were decreased in cells expressing FL-mHtt, highly suggesting decreased de novo synthesis of glutathione. Enhanced intracellular total glutathione, despite decreased synthesis, could be explained by decreased extracellular glutathione in mutant cells. This occurred concomitantly with decreased mRNA expression levels and activity of the multidrug resistance protein 1 (Mrp1), a transport protein that mediates cellular export of glutathione disulfide and glutathione conjugates. Additionally, inhibition of Mrp1 enhanced intracellular GSH in wild-type cells only. These data suggest that FL-mHtt affects the export of glutathione by decreasing the expression of Mrp1. Data further suggest that boosting of GSH-related antioxidant defense mechanisms induced by FL-mHtt is insufficient to counterbalance increased ROS formation and emergent apoptotic features in HD striatal cells.
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Affiliation(s)
- Márcio Ribeiro
- CNC-Center for Neuroscience and Cell Biology, University of Coimbra, Coimbra, Portugal
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59
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Brose RD, Shin G, McGuinness MC, Schneidereith T, Purvis S, Dong GX, Keefer J, Spencer F, Smith KD. Activation of the stress proteome as a mechanism for small molecule therapeutics. Hum Mol Genet 2012; 21:4237-52. [PMID: 22752410 DOI: 10.1093/hmg/dds247] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023] Open
Abstract
Various small molecule pharmacologic agents with different known functions produce similar outcomes in diverse Mendelian and complex disorders, suggesting that they may induce common cellular effects. These molecules include histone deacetylase inhibitors, 4-phenylbutyrate (4PBA) and trichostatin A, and two small molecules without direct histone deacetylase inhibitor activity, hydroxyurea (HU) and sulforaphane. In some cases, the therapeutic effects of histone deacetylase inhibitors have been attributed to an increase in expression of genes related to the disease-causing gene. However, here we show that the pharmacological induction of mitochondrial biogenesis was necessary for the potentially therapeutic effects of 4PBA or HU in two distinct disease models, X-linked adrenoleukodystrophy and sickle cell disease. We hypothesized that a common cellular response to these four molecules is induction of mitochondrial biogenesis and peroxisome proliferation and activation of the stress proteome, or adaptive cell survival response. Treatment of human fibroblasts with these four agents induced mitochondrial and peroxisomal biogenesis as monitored by flow cytometry, immunofluorescence and/or western analyses. In treated normal human fibroblasts, all four agents induced the adaptive cell survival response: heat shock, unfolded protein, autophagic and antioxidant responses and the c-jun N-terminal kinase pathway, at the transcriptional and translational levels. Thus, activation of the evolutionarily conserved stress proteome and mitochondrial biogenesis may be a common cellular response to such small molecule therapy and a common basis of therapeutic action in various diseases. Modulation of this novel therapeutic target could broaden the range of treatable diseases without directly targeting the causative genetic abnormalities.
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Affiliation(s)
- Rebecca Deering Brose
- McKusick-Nathans Institute of Genetic Medicine, Johns Hopkins University, Baltimore, MD 21205, USA
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60
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Ehrlich ME. Huntington's disease and the striatal medium spiny neuron: cell-autonomous and non-cell-autonomous mechanisms of disease. Neurotherapeutics 2012; 9:270-84. [PMID: 22441874 PMCID: PMC3337013 DOI: 10.1007/s13311-012-0112-2] [Citation(s) in RCA: 107] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022] Open
Abstract
Huntington's disease is an autosomal dominant disorder caused by a mutation in the gene encoding the protein huntingtin on chromosome 4. The mutation is an expanded CAG repeat in the first exon, encoding a polyglutamine tract. If the polyglutamine tract is > 40, penetrance is 100% and death is inevitable. Despite the widespread expression of huntingtin, HD has long been considered primarily as a disease of the striatum. It is characterized by selective vulnerability with dysfunction followed by death of the medium size spiny neuron. Considerable effort is being expended to determine whether striatal damage is cell-autonomous, non-cell-autonomous, requiring cell-cell and region to region communication, or both. We review data supporting both mechanisms. We also attempt to organize the data into common mechanisms that may arise outside the medium, spiny neuron, but ultimately have their greatest impact in the striatum.
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Affiliation(s)
- Michelle E Ehrlich
- Department of Pediatrics, Mount Sinai School of Medicine, Annenberg 14-44, 1 Gustave L. Levy Place, New York, NY 10019, USA.
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61
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Jin YN, Hwang WY, Jo C, Johnson GVW. Metabolic state determines sensitivity to cellular stress in Huntington disease: normalization by activation of PPARγ. PLoS One 2012; 7:e30406. [PMID: 22276192 PMCID: PMC3262812 DOI: 10.1371/journal.pone.0030406] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2011] [Accepted: 12/15/2011] [Indexed: 11/17/2022] Open
Abstract
Impairments in mitochondria and transcription are important factors in the pathogenesis of Huntington disease (HD), a neurodegenerative disease caused by a polyglutamine expansion in the huntingtin protein. This study investigated the effect of different metabolic states and peroxisome proliferator-activated receptor γ (PPARγ) activation on sensitivity to cellular stressors such as H(2)O(2) or thapsigargin in HD. Striatal precursor cells expressing wild type (STHdh(Q7)) or mutant huntingtin (STHdh(Q111)) were prepared in different metabolic conditions (glucose vs. pyruvate). Due to the fact that STHdh(Q111) cells exhibit mitochondrial deficits, we expected that in the pyruvate condition, where ATP is generated primarily by the mitochondria, there would be greater differences in cell death between the two cell types compared to the glucose condition. Intriguingly, it was the glucose condition that gave rise to greater differences in cell death. In the glucose condition, thapsigargin treatment resulted in a more rapid loss of mitochondrial membrane potential (ΔΨm), a greater activation of caspases (3, 8, and 9), and a significant increase in superoxide/reactive oxygen species (ROS) in STHdh(Q111) compared to STHdh(Q7), while both cell types showed similar kinetics of ΔΨm-loss and similar levels of superoxide/ROS in the pyruvate condition. This suggests that bioenergetic deficiencies are not the primary contributor to the enhanced sensitivity of STHdh(Q111) cells to stressors compared to the STHdh(Q7) cells. PPARγ activation significantly attenuated thapsigargin-induced cell death, concomitant with an inhibition of caspase activation, a delay in ΔΨm loss, and a reduction of superoxide/ROS generation in STHdh(Q111) cells. Expression of mutant huntingtin in primary neurons induced superoxide/ROS, an effect that was significantly reduced by constitutively active PPARγ. These results provide significant insight into the bioenergetic disturbances in HD with PPARγ being a potential therapeutic target for HD.
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Affiliation(s)
- Youngnam N Jin
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York, United States of America
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62
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Raymond LA, André VM, Cepeda C, Gladding CM, Milnerwood AJ, Levine MS. Pathophysiology of Huntington's disease: time-dependent alterations in synaptic and receptor function. Neuroscience 2011; 198:252-73. [PMID: 21907762 PMCID: PMC3221774 DOI: 10.1016/j.neuroscience.2011.08.052] [Citation(s) in RCA: 240] [Impact Index Per Article: 17.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2011] [Revised: 07/31/2011] [Accepted: 08/22/2011] [Indexed: 01/27/2023]
Abstract
Huntington's disease (HD) is a progressive, fatal neurological condition caused by an expansion of CAG (glutamine) repeats in the coding region of the Huntington gene. To date, there is no cure but great strides have been made to understand pathophysiological mechanisms. In particular, genetic animal models of HD have been instrumental in elucidating the progression of behavioral and physiological alterations, which had not been possible using classic neurotoxin models. Our groups have pioneered the use of transgenic HD mice to examine the excitotoxicity hypothesis of striatal neuronal dysfunction and degeneration, as well as alterations in excitation and inhibition in striatum and cerebral cortex. In this review, we focus on synaptic and receptor alterations of striatal medium-sized spiny (MSNs) and cortical pyramidal neurons in genetic HD mouse models. We demonstrate a complex series of alterations that are region-specific and time-dependent. In particular, many changes are bidirectional depending on the degree of disease progression, that is, early vs. late, and also on the region examined. Early synaptic dysfunction is manifested by dysregulated glutamate release in striatum followed by progressive disconnection between cortex and striatum. The differential effects of altered glutamate release on MSNs originating the direct and indirect pathways is also elucidated, with the unexpected finding that cells of the direct striatal pathway are involved early in the course of the disease. In addition, we review evidence for early N-methyl-D-aspartate receptor (NMDAR) dysfunction leading to enhanced sensitivity of extrasynaptic receptors and a critical role of GluN2B subunits. Some of the alterations in late HD could be compensatory mechanisms designed to cope with early synaptic and receptor dysfunctions. The main findings indicate that HD treatments need to be designed according to the stage of disease progression and should consider regional differences.
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Affiliation(s)
- Lynn A. Raymond
- Department of Psychiatry and Brain Research Centre, University of British Columbia, Vancouver, Canada
| | - Véronique M. André
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Carlos Cepeda
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
| | - Clare M. Gladding
- Department of Psychiatry and Brain Research Centre, University of British Columbia, Vancouver, Canada
| | - Austen J. Milnerwood
- Department of Psychiatry and Brain Research Centre, University of British Columbia, Vancouver, Canada
| | - Michael S. Levine
- Intellectual and Developmental Disabilities Research Center, Semel Institute for Neuroscience and Human Behavior, David Geffen School of Medicine, University of California Los Angeles, Los Angeles, CA, USA
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63
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Naia L, Ribeiro MJ, Rego AC. Mitochondrial and metabolic-based protective strategies in Huntington's disease: the case of creatine and coenzyme Q. Rev Neurosci 2011; 23:13-28. [PMID: 22150069 DOI: 10.1515/rns.2011.060] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/20/2011] [Accepted: 10/26/2011] [Indexed: 01/15/2023]
Abstract
Huntington's disease (HD) is a neurodegenerative genetic disorder caused by an expansion of CAG repeats in the HD gene encoding for huntingtin (Htt), resulting in progressive death of striatal neurons, with clinical symptoms of chorea, dementia and dramatic weight loss. Metabolic and mitochondrial dysfunction caused by the expanded polyglutamine sequence have been described along with other mechanisms of neurodegeneration previously described in human tissues and animal models of HD. In this review, we focus on mitochondrial and metabolic disturbances affecting both the central nervous system and peripheral cells, including mitochondrial DNA damage, mitochondrial complexes defects, loss of calcium homeostasis and transcriptional deregulation. Glucose abnormalities have also been described in peripheral tissues of HD patients and in HD animal and cellular models. Moreover, there are no effective neuroprotective treatments available in HD. Thus, we briefly discuss the role of creatine and coenzyme Q10 that target mitochondrial dysfunction and impaired bioenergetics and have been previously used in HD clinical trials.
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Affiliation(s)
- Luana Naia
- Center for Neuroscience and Cell Biology, University of Coimbra, 3004-504 Coimbra, Portugal
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64
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Bowman AB, Kwakye GF, Herrero Hernández E, Aschner M. Role of manganese in neurodegenerative diseases. J Trace Elem Med Biol 2011; 25:191-203. [PMID: 21963226 PMCID: PMC3230726 DOI: 10.1016/j.jtemb.2011.08.144] [Citation(s) in RCA: 256] [Impact Index Per Article: 18.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2011] [Accepted: 08/16/2011] [Indexed: 12/17/2022]
Abstract
Manganese (Mn) is an essential ubiquitous trace element that is required for normal growth, development and cellular homeostasis. Exposure to high Mn levels causes a clinical disease characterized by extrapyramidal symptom resembling idiopathic Parkinson's disease (IPD). The present review focuses on the role of various transporters in maintaining brain Mn homeostasis along with recent methodological advances in real-time measurements of intracellular Mn levels. We also provide an overview on the role for Mn in IPD, discussing the similarities (and differences) between manganism and IPD, and the relationship between α-synuclein and Mn-related protein aggregation, as well as mitochondrial dysfunction, Mn and PD. Additional sections of the review discuss the link between Mn and Huntington's disease (HD), with emphasis on huntingtin function and the potential role for altered Mn homeostasis and toxicity in HD. We conclude with a brief survey on the potential role of Mn in the etiologies of Alzheimer's disease (AD), amyotrophic lateral sclerosis (ALS) and prion disease. Where possible, we discuss the mechanistic commonalities inherent to Mn-induced neurotoxicity and neurodegenerative disorders.
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Affiliation(s)
- Aaron B Bowman
- Department of Neurology, Vanderbilt Kennedy Center, Center for Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN 37232-8552, United States
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65
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Schneider L, Giordano S, Zelickson BR, Johnson M, Benavides G, Ouyang X, Fineberg N, Darley-Usmar VM, Zhang J. Differentiation of SH-SY5Y cells to a neuronal phenotype changes cellular bioenergetics and the response to oxidative stress. Free Radic Biol Med 2011; 51:2007-17. [PMID: 21945098 PMCID: PMC3208787 DOI: 10.1016/j.freeradbiomed.2011.08.030] [Citation(s) in RCA: 157] [Impact Index Per Article: 11.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/10/2011] [Revised: 08/23/2011] [Accepted: 08/24/2011] [Indexed: 12/13/2022]
Abstract
Cell differentiation is associated with changes in metabolism and function. Understanding these changes during differentiation is important in the context of stem cell research, cancer, and neurodegenerative diseases. An early event in neurodegenerative diseases is the alteration of mitochondrial function and increased oxidative stress. Studies using both undifferentiated and differentiated SH-SY5Y neuroblastoma cells have shown distinct responses to cellular stressors; however, the mechanisms remain unclear. We hypothesized that because the regulation of glycolysis and oxidative phosphorylation is modulated during cellular differentiation, this would change bioenergetic function and the response to oxidative stress. To test this, we used retinoic acid (RA) to induce differentiation of SH-SY5Y cells and assessed changes in cellular bioenergetics using extracellular flux analysis. After exposure to RA, the SH-SY5Y cells had an increased mitochondrial membrane potential, without changing mitochondrial number. Differentiated cells exhibited greater stimulation of mitochondrial respiration with uncoupling and an increased bioenergetic reserve capacity. The increased reserve capacity in the differentiated cells was suppressed by the inhibitor of glycolysis 2-deoxy-d-glucose. Furthermore, we found that differentiated cells were substantially more resistant to cytotoxicity and mitochondrial dysfunction induced by the reactive lipid species 4-hydroxynonenal or the reactive oxygen species generator 2,3-dimethoxy-1,4-naphthoquinone. We then analyzed the levels of selected mitochondrial proteins and found an increase in complex IV subunits, which we propose contributes to the increase in reserve capacity in the differentiated cells. Furthermore, we found an increase in MnSOD that could, at least in part, account for the increased resistance to oxidative stress. Our findings suggest that profound changes in mitochondrial metabolism and antioxidant defenses occur upon differentiation of neuroblastoma cells to a neuron-like phenotype.
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Affiliation(s)
- Lonnie Schneider
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Samantha Giordano
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Blake R. Zelickson
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Michelle Johnson
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Gloria Benavides
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Xiaosen Ouyang
- Department of Pathology, University of Alabama at Birmingham
- Department of Veterans Affairs, Birmingham VA Medical Center
| | - Naomi Fineberg
- Department of Biostatistics, UAB School of Public Health
| | - Victor M. Darley-Usmar
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
| | - Jianhua Zhang
- Center for Free Radical Biology, University of Alabama at Birmingham
- Department of Pathology, University of Alabama at Birmingham
- Department of Veterans Affairs, Birmingham VA Medical Center
- Corresponding author: Jianhua Zhang, Ph.D., Department of Pathology, University of Alabama at Birmingham, BMRII-534, 901 19 Street South, Birmingham, AL 35294-0017, USA, Phone: 205-996-5153; Fax: 205-934-7447;
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Reddy PH, Shirendeb UP. Mutant huntingtin, abnormal mitochondrial dynamics, defective axonal transport of mitochondria, and selective synaptic degeneration in Huntington's disease. Biochim Biophys Acta Mol Basis Dis 2011; 1822:101-10. [PMID: 22080977 DOI: 10.1016/j.bbadis.2011.10.016] [Citation(s) in RCA: 130] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/17/2011] [Revised: 10/25/2011] [Accepted: 10/25/2011] [Indexed: 11/19/2022]
Abstract
Huntington's disease (HD) is a progressive, fatal neurodegenerative disease caused by expanded polyglutamine repeats in the HD gene. HD is characterized by chorea, seizures, involuntary movements, dystonia, cognitive decline, intellectual impairment and emotional disturbances. Research into mutant huntingtin (Htt) and mitochondria has found that mutant Htt interacts with the mitochondrial protein dynamin-related protein 1 (Drp1), enhances GTPase Drp1 enzymatic activity, and causes excessive mitochondrial fragmentation and abnormal distribution, leading to defective axonal transport of mitochondria and selective synaptic degeneration. This article summarizes latest developments in HD research and focuses on the role of abnormal mitochondrial dynamics and defective axonal transport in HD neurons. This article also discusses the therapeutic strategies that decrease mitochondrial fragmentation and neuronal damage in HD.
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Affiliation(s)
- P Hemachandra Reddy
- Neurogenetics Laboratory, Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, 505 NW 185th Avenue, Beaverton, OR 97006, USA.
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67
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Brooks SP, Jones L, Dunnett SB. Comparative analysis of pathology and behavioural phenotypes in mouse models of Huntington's disease. Brain Res Bull 2011; 88:81-93. [PMID: 22004616 DOI: 10.1016/j.brainresbull.2011.10.002] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2011] [Accepted: 10/03/2011] [Indexed: 12/30/2022]
Abstract
The longitudinal characterisation of Huntington's disease (HD) mouse lines is essential for the understanding of the differential developmental time course, nature and severity of phenotype progression over time. This overview outlines detailed behavioural, neuropathological and gene expression studies in four HD mouse lines: R6/1, YAC128, HdhQ92 and HdhQ150 and outlines their relevance to human HD. The review describes the similarities and differences between the models at the behavioural, anatomical and genetic levels of pathology and how these phenotypes interact in the development of disease in the lines. The HdhQ150 mouse demonstrates the most similarities to the functional deficits observed in human HD. The neuropathological profile with early cortical development of intense aggregate/inclusion pathology in the YAC128 mouse suggests that this line most resembles the development of inclusion pathology in the human disease. The gene expression analyses of the mouse lines find significant similarities between each of the lines and human HD, which converge as the mice age. In the YAC128 and HdhQ92 mouse lines some severe functional deficits are progressive whilst others are not, despite the concomitant ongoing development of neuropathological and gene expression changes. We suggest that the YAC128 and R6/1 lines may be more representative of the juvenile form of HD. The suitability of the different mouse models studied here for different types of pre-clinical therapeutic trials is discussed.
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Affiliation(s)
- Simon P Brooks
- Brain Repair Group, School of Biosciences, Cardiff University, Wales, UK.
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68
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Kwakye GF, Li D, Bowman AB. Novel high-throughput assay to assess cellular manganese levels in a striatal cell line model of Huntington's disease confirms a deficit in manganese accumulation. Neurotoxicology 2011; 32:630-9. [PMID: 21238486 PMCID: PMC3135664 DOI: 10.1016/j.neuro.2011.01.002] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/26/2010] [Revised: 12/19/2010] [Accepted: 01/07/2011] [Indexed: 02/05/2023]
Abstract
In spite of the essentiality of manganese (Mn) as a trace element necessary for a variety of physiological processes, Mn in excess accumulates in the brain and has been associated with dysfunction and degeneration of the basal ganglia. Despite the high sensitivity, limited chemical interference, and multi-elemental advantages of traditional methods for measuring Mn levels, they lack the feasibility to assess Mn transport dynamics in a high-throughput manner. Our lab has previously reported decreased net Mn accumulation in a mutant striatal cell line model of Huntington's disease (STHdh(Q111/Q111)) relative to wild-type following Mn exposure. To evaluate Mn transport dynamics in these striatal cell lines, we have developed a high-throughput fluorescence-quenching extraction assay (Cellular Fura-2 Manganese Extraction Assay - CFMEA). CFMEA utilizes changes in fura-2 fluorescence upon excitation at 360 nm (Ca(2+) isosbestic point) and emission at 535 nm, as an indirect measurement of total cellular Mn content. Here, we report the establishment, development, and application of CFMEA. Specifically, we evaluate critical extraction and assay conditions (e.g. extraction buffer, temperature, and fura-2 concentration) required for efficient extraction and quantitative detection of cellular Mn from cultured cells. Mn concentrations can be derived from quenching of fura-2 fluorescence with standard curves based on saturation one-site specific binding kinetics. Importantly, we show that extracted calcium and magnesium concentrations below 10 μM have negligible influence on measurements of Mn by fura-2. CFMEA is able to accurately measure extracted Mn levels from cultured striatal cells over a range of at least 0.1-10 μM. We have used two independent Mn supplementation approaches to validate the quantitative accuracy of CFMEA over a 0-200 μM cellular Mn-exposure range. Finally, we have utilized CFMEA to experimentally confirm a deficit in net Mn accumulation in the mutant HD striatal cell line versus wild-type cells. To conclude, we have developed and applied a novel assay to assess Mn transport dynamics in cultured striatal cell lines. CFMEA provides a rapid means of evaluating Mn transport kinetics in cellular toxicity and disease models.
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Affiliation(s)
- Gunnar F. Kwakye
- Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
- Vanderbilt Kennedy Center for Research on Human Development, Nashville, TN
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN
- Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN
| | - Daphne Li
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
- Vanderbilt Kennedy Center for Research on Human Development, Nashville, TN
| | - Aaron B. Bowman
- Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN
- Vanderbilt Kennedy Center for Research on Human Development, Nashville, TN
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN
- Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN
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69
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Kwakye GF, Li D, Kabobel OA, Bowman AB. Cellular fura-2 manganese extraction assay (CFMEA). ACTA ACUST UNITED AC 2011; Chapter 12:Unit12.18. [PMID: 21553393 DOI: 10.1002/0471140856.tx1218s48] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
Cellular manganese (Mn) uptake and transport dynamics can be measured using a cellular fura-2 manganese extraction assay (CFMEA). The assay described here uses immortalized murine striatal cell line and primary cortical astrocytes, but the method is equally adaptable to other cultured mammalian cells. An ultrasensitive fluorescent nucleic acid stain for quantification of double-stranded DNA (dsDNA) in solution, Quant-iT PicoGreen, has been utilized for normalization of Mn concentration in the cultured cells, following Mn (II) chloride (MnCl(2)) exposure. Depending on the cell type and density, other methods, e.g., protein determination assays or cell counts, may also be used for normalization. Methods are described for rapidly stopping Mn uptake and transport processes at specified times, extraction, and quantification of cellular Mn content, and normalization of Mn levels to dsDNA concentration.
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Affiliation(s)
- Gunnar F Kwakye
- Vanderbilt University Medical Center, Nashville, Tennessee, USA
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70
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Bioenergetic dysfunction in Huntington's disease human cybrids. Exp Neurol 2011; 231:127-34. [PMID: 21684277 DOI: 10.1016/j.expneurol.2011.05.024] [Citation(s) in RCA: 48] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/03/2011] [Revised: 04/30/2011] [Accepted: 05/28/2011] [Indexed: 12/23/2022]
Abstract
In this work we studied the mitochondrial-associated metabolic pathways in Huntington's disease (HD) versus control (CTR) cybrids, a cell model in which the contribution of mitochondrial defects from patients is isolated. HD cybrids exhibited an interesting increase in ATP levels, when compared to CTR cybrids. Concomitantly, we observed increased glycolytic rate in HD cybrids, as revealed by increased lactate/pyruvate ratio, which was reverted after inhibition of glycolysis. A decrease in glucose-6-phosphate dehydrogenase activity in HD cybrids further indicated decreased rate of the pentose-phosphate pathway. ATP levels of HD cybrids were significantly decreased under glycolysis inhibition, which was accompanied by a decrease in phosphocreatine. Nevertheless, pyruvate supplementation could not recover HD cybrids' ATP or phosphocreatine levels, suggesting a dysfunction in mitochondrial use of that substrate. Oligomycin also caused a decrease in ATP levels, suggesting a partial support of ATP generation by the mitochondria. Nevertheless, mitochondrial NADH/NAD(t) levels were decreased in HD cybrids, which was correlated with a decrease in pyruvate dehydrogenase activity and protein expression, suggesting decreased tricarboxylic acid cycle (TCA) input from glycolysis. Interestingly, the activity of alpha-ketoglutarate dehydrogenase, a critical enzyme complex that links the TCA to amino acid synthesis and degradation, was increased in HD cybrids. In accordance, mitochondrial levels of glutamate were increased and alanine was decreased, whereas aspartate and glutamine levels were unchanged in HD cybrids. Conversely, malate dehydrogenase activity from total cell extracts was unchanged in HD cybrids. Our results suggest that inherent dysfunction of mitochondria from HD patients affects cellular bioenergetics in an otherwise functional nuclear background.
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71
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Reddy PH, Reddy TP. Mitochondria as a therapeutic target for aging and neurodegenerative diseases. Curr Alzheimer Res 2011; 8:393-409. [PMID: 21470101 PMCID: PMC3295247 DOI: 10.2174/156720511795745401] [Citation(s) in RCA: 178] [Impact Index Per Article: 12.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2010] [Accepted: 11/11/2010] [Indexed: 01/14/2023]
Abstract
Mitochondria are cytoplasmic organelles responsible for life and death. Extensive evidence from animal models, postmortem brain studies of and clinical studies of aging and neurodegenerative diseases suggests that mitochondrial function is defective in aging and neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and amyotrophic lateral sclerosis. Several lines of research suggest that mitochondrial abnormalities, including defects in oxidative phosphorylation, increased accumulation of mitochondrial DNA defects, impaired calcium influx, accumulation of mutant proteins in mitochondria, and mitochondrial membrane potential dissipation are important cellular changes in both early and late-onset neurodegenerative diseases. Further, emerging evidence suggests that structural changes in mitochondria, including increased mitochondrial fragmentation and decreased mitochondrial fusion, are critical factors associated with mitochondrial dysfunction and cell death in aging and neurodegenerative diseases. This paper discusses research that elucidates features of mitochondria that are associated with cellular dysfunction in aging and neurodegenerative diseases and discusses mitochondrial structural and functional changes, and abnormal mitochondrial dynamics in neurodegenerative diseases. It also outlines mitochondria-targeted therapeutics in neurodegenerative diseases.
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Affiliation(s)
- P H Reddy
- Neurogenetics Laboratory, Division of Neuroscience, Oregon National Primate Research Center, Oregon Health & Science University, Beaverton, OR 97006, USA.
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72
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Zündorf G, Reiser G. Calcium dysregulation and homeostasis of neural calcium in the molecular mechanisms of neurodegenerative diseases provide multiple targets for neuroprotection. Antioxid Redox Signal 2011; 14:1275-88. [PMID: 20615073 PMCID: PMC3122891 DOI: 10.1089/ars.2010.3359] [Citation(s) in RCA: 329] [Impact Index Per Article: 23.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/29/2022]
Abstract
The intracellular free calcium concentration subserves complex signaling roles in brain. Calcium cations (Ca(2+)) regulate neuronal plasticity underlying learning and memory and neuronal survival. Homo- and heterocellular control of Ca(2+) homeostasis supports brain physiology maintaining neural integrity. Ca(2+) fluxes across the plasma membrane and between intracellular organelles and compartments integrate diverse cellular functions. A vast array of checkpoints controls Ca(2+), like G protein-coupled receptors, ion channels, Ca(2+) binding proteins, transcriptional networks, and ion exchangers, in both the plasma membrane and the membranes of mitochondria and endoplasmic reticulum. Interactions between Ca(2+) and reactive oxygen species signaling coordinate signaling, which can be either beneficial or detrimental. In neurodegenerative disorders, cellular Ca(2+)-regulating systems are compromised. Oxidative stress, perturbed energy metabolism, and alterations of disease-related proteins result in Ca(2+)-dependent synaptic dysfunction, impaired plasticity, and neuronal demise. We review Ca(2+) control processes relevant for physiological and pathophysiological conditions in brain tissue. Dysregulation of Ca(2+) is decisive for brain cell death and degeneration after ischemic stroke, long-term neurodegeneration in Alzheimer's disease, Parkinson's disease, Huntington's disease, inflammatory processes, such as in multiple sclerosis, epileptic sclerosis, and leucodystrophies. Understanding the underlying molecular processes is of critical importance for the development of novel therapeutic strategies to prevent neurodegeneration and confer neuroprotection.
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Affiliation(s)
- Gregor Zündorf
- Institut für Neurobiochemie, Medizinische Fakultät der Otto-von-Guericke-Universität Magdeburg, Magdeburg, Germany
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73
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Abstract
Huntington disease (HD) is an autosomal dominant neurodegenerative disease with complete penetrance. Although the understanding of the cellular mechanisms that drive neurodegeneration in HD and account for the characteristic pattern of neuronal vulnerability is incomplete, defects in energy metabolism, particularly mitochondrial function, represent a common thread in studies of HD pathogenesis in humans and animal models. Here we review the clinical, biochemical, and molecular evidence of an energy deficit in HD and discuss the mechanisms underlying mitochondrial and related alterations.
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Affiliation(s)
- Fanny Mochel
- INSERM UMR S975, Institut du Cerveau et de la Moelle,
AP-HP, Département de Génétique, and
Unité Fonctionnelle Neurométabolique, Hôpital La Salpêtrière, Paris, France.
Université Pierre et Marie Curie, Paris, France.
Department of Neurology, University of Texas Southwestern Medical Center and VA North Texas Medical Center, Dallas, Texas, USA.
Neuromuscular Center, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas, USA
| | - Ronald G. Haller
- INSERM UMR S975, Institut du Cerveau et de la Moelle,
AP-HP, Département de Génétique, and
Unité Fonctionnelle Neurométabolique, Hôpital La Salpêtrière, Paris, France.
Université Pierre et Marie Curie, Paris, France.
Department of Neurology, University of Texas Southwestern Medical Center and VA North Texas Medical Center, Dallas, Texas, USA.
Neuromuscular Center, Institute for Exercise and Environmental Medicine, Texas Health Presbyterian Hospital, Dallas, Texas, USA
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74
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Rosenstock TR, Bertoncini CRA, Teles AV, Hirata H, Fernandes MJS, Smaili SS. Glutamate-induced alterations in Ca2+ signaling are modulated by mitochondrial Ca2+ handling capacity in brain slices of R6/1 transgenic mice. Eur J Neurosci 2011; 32:60-70. [PMID: 20608968 DOI: 10.1111/j.1460-9568.2010.07268.x] [Citation(s) in RCA: 22] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Huntington's disease is a neurodegenerative disorder caused by an expansion of CAGs repeats and characterized by alterations in mitochondrial functions. Although changes in Ca(2+) handling have been suggested, the mechanisms involved are not completely understood. The aim of this study was to investigate the possible alterations in Ca(2+) handling capacity and the relationship with mitochondrial dysfunction evaluated by NAD(P)H fluorescence, reactive oxygen species levels, mitochondrial membrane potential (DeltaPsi(m)) measurements and respiration in whole brain slices from R6/1 mice of different ages, evaluated in situ by real-time real-space microscopy. We show that the cortex and striatum of the 9-month-old R6/1 transgenic mice present a significant sustained increase in cytosolic Ca(2+) induced by glutamate (Glu). This difference in Glu response was partially reduced in R6/1 when in the absence of extracellular Ca(2+), indicating that N-methyl-D-aspartate receptors participation in this response is more important in transgenic mice. In addition, Glu also lead to a decrease in NAD(P)H fluorescence, a loss in DeltaPsi(m) and a further increase in respiration, which may have evoked a decrease in mitochondrial Ca(2+) Ca(2+)(m) uptake capacity. Taken together, these results show that alterations in Ca(2+) homeostasis in transgenic mice are associated with a decrease in Ca(2+)(m) uptake mechanism with a diminished Ca(2+) handling ability that ultimately causes dysfunctions and worsening of the neurodegenerative and the disease processes.
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Affiliation(s)
- T R Rosenstock
- Departamento de Farmacologia, Universidade Federal de São Paulo (UNIFESP/EPM), São Paulo, SP, Brazil
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75
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Mitochondrial bioenergetics and dynamics in Huntington's disease: tripartite synapses and selective striatal degeneration. J Bioenerg Biomembr 2010; 42:227-34. [PMID: 20454921 DOI: 10.1007/s10863-010-9287-6] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
Abstract
Preferential striatal neurodegeneration is a hallmark of Huntington's disease (HD) pathogenesis, which has been associated with mitochondrial dysfunction. Evidence from genetic HD models suggest that mutant huntingtin (mHtt) compromises mitochondrial bioenergetics and dynamics, preventing efficient calcium handling and ATP generation in neuronal networks. Striatal neurons receive abundant glutamatergic input from the cortex, forming tripartite synapses with astrocytic partners. These are involved in bidirectional communication, play neuroprotective roles, and emerging evidence suggests that astrocyte dysfunction supports non-cell autonomous neurodegeneration. In addition to mHtt effects, inherent mitochondria vulnerability within striatal neurons and astrocytes may contribute for preferential neurodegeneration in HD. Dysfunctional astrocytic mitochondria in cortico-striatal tripartite synapses might be particularly relevant in the pathogenesis of juvenile/infantile HD, frequently associated with seizures and abnormally large mHtt polyglutamine expansions. This review discusses our work, primarily addressing in situ mitochondrial function in neurons and astrocytes, in the context of related work within the HD-mitochondria field.
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76
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Perry GM, Tallaksen-Greene S, Kumar A, Heng MY, Kneynsberg A, van Groen T, Detloff PJ, Albin RL, Lesort M. Mitochondrial calcium uptake capacity as a therapeutic target in the R6/2 mouse model of Huntington's disease. Hum Mol Genet 2010; 19:3354-71. [PMID: 20558522 PMCID: PMC2916705 DOI: 10.1093/hmg/ddq247] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2010] [Accepted: 06/10/2010] [Indexed: 11/14/2022] Open
Abstract
Huntington's disease (HD) is an incurable autosomal-dominant neurodegenerative disorder initiated by an abnormally expanded polyglutamine domain in the huntingtin protein. It is proposed that abnormal mitochondrial Ca2+ capacity results in an increased susceptibility to mitochondrial permeability transition (MPT) induction that may contribute significantly to HD pathogenesis. The in vivo contribution of these hypothesized defects remains to be elucidated. In this proof-of-principle study, we examined whether increasing mitochondrial Ca2+ capacity could ameliorate the well-characterized phenotype of the R6/2 transgenic mouse model. Mouse models lacking cyclophilin D demonstrate convincingly that cyclophilin D is an essential component and a key regulator of MPT induction. Mitochondria of cyclophilin D knockout mice are particularly resistant to Ca2+ overload. We generated R6/2 mice with normal, reduced or absent cyclophilin D expression and examined the effect of increasing mitochondrial Ca2+ capacity on the behavioral and neuropathological features of the R6/2 model. A predicted outcome of this approach was the finding that cyclophilin D deletion enhanced the R6/2 brain mitochondria Ca2+ capacity significantly. Increased neuronal mitochondrial Ca2+ capacity failed to ameliorate either the behavioral and neuropathological features of R6/2 mice. We found no alterations in body weight changes, lifespan, RotaRod performances, grip strength, overall activity and no significant effect on the neuropathological features of R6/2 mice. The results of this study demonstrate that increasing neuronal mitochondrial Ca2+-buffering capacity is not beneficial in the R6/2 mouse model of HD.
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Affiliation(s)
| | - Sara Tallaksen-Greene
- VAAAHS GRECC, Ann Arbor, MI, USA and
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | | | - Mary Y. Heng
- VAAAHS GRECC, Ann Arbor, MI, USA and
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
| | | | | | - Peter J. Detloff
- Department of Biochemistry & Molecular Genetics, University of Alabama at Birmingham, Birmingham, AL, USA
| | - Roger L. Albin
- VAAAHS GRECC, Ann Arbor, MI, USA and
- Department of Neurology, University of Michigan, Ann Arbor, MI, USA
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77
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Miller JP, Holcomb J, Al-Ramahi I, de Haro M, Gafni J, Zhang N, Kim E, Sanhueza M, Torcassi C, Kwak S, Botas J, Hughes RE, Ellerby LM. Matrix metalloproteinases are modifiers of huntingtin proteolysis and toxicity in Huntington's disease. Neuron 2010; 67:199-212. [PMID: 20670829 PMCID: PMC3098887 DOI: 10.1016/j.neuron.2010.06.021] [Citation(s) in RCA: 138] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/15/2010] [Indexed: 01/27/2023]
Abstract
Proteolytic cleavage of huntingtin (Htt) is known to be a key event in the pathogenesis of Huntington's disease (HD). Our understanding of proteolytic processing of Htt has thus far focused on the protease families-caspases and calpains. Identifying critical proteases involved in Htt proteolysis and toxicity using an unbiased approach has not been reported. To accomplish this, we designed a high-throughput western blot-based screen to examine the generation of the smallest N-terminal polyglutamine-containing Htt fragment. We screened 514 siRNAs targeting the repertoire of human protease genes. This screen identified 11 proteases that, when inhibited, reduced Htt fragment accumulation. Three of these belonged to the matrix metalloproteinase (MMP) family. One family member, MMP-10, directly cleaves Htt and prevents cell death when knocked down in striatal Hdh(111Q/111Q) cells. Correspondingly, MMPs are activated in HD mouse models, and loss of function of Drosophila homologs of MMPs suppresses Htt-induced neuronal dysfunction in vivo.
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Affiliation(s)
| | | | - Ismael Al-Ramahi
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
| | - Maria de Haro
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
| | | | | | - Eugene Kim
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
| | - Mario Sanhueza
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
| | | | - Seung Kwak
- CHDI Foundation, Inc., 300 Alexander Park, Suite 110, Princeton, NJ 08540
| | - Juan Botas
- Department of Molecular and Human Genetics, Baylor College of Medicine, Houston, Texas 77030
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78
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Kidd SK, Schneider JS. Protection of dopaminergic cells from MPP+-mediated toxicity by histone deacetylase inhibition. Brain Res 2010; 1354:172-8. [PMID: 20654591 DOI: 10.1016/j.brainres.2010.07.041] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2010] [Revised: 07/12/2010] [Accepted: 07/14/2010] [Indexed: 01/08/2023]
Abstract
Although the pathophysiological processes involved in dopamine (DA) neuron degeneration in Parkinson's disease (PD) are not completely known, apoptotic cell death has been suggested to be involved and can be modeled in DAergic cell lines using the mitochondrial toxin 1-methyl-4-phenylpyridinium (MPP(+)). Recently, it has been suggested that histone deacetylase inhibitors (HDACIs) may reduce apoptotic cell death in various model systems. However, their utility in interfering with DA cell death remains unclear. The HDACIs sodium butyrate (NaB), valproate (VPA) and suberoylanilide hydroxamic acid (SAHA) were tested for their ability to prevent MPP(+)-mediated cytotoxicity in human derived SK-N-SH and rat derived MES 23.5 cells. All three HDACIs at least partially prevented MPP(+)-mediated apoptotic cell death. The protective effects of these HDACIs coincided with significant increases in histone acetylation. These results suggest that HDACIs may be potentially neuroprotective against DA cell death and should be explored further in animal models of PD.
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Affiliation(s)
- Sarah K Kidd
- Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA 19107, USA
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79
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Zuccato C, Valenza M, Cattaneo E. Molecular mechanisms and potential therapeutical targets in Huntington's disease. Physiol Rev 2010; 90:905-81. [PMID: 20664076 DOI: 10.1152/physrev.00041.2009] [Citation(s) in RCA: 617] [Impact Index Per Article: 41.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Huntington's disease (HD) is a neurodegenerative disorder caused by a CAG repeat expansion in the gene encoding for huntingtin protein. A lot has been learned about this disease since its first description in 1872 and the identification of its causative gene and mutation in 1993. We now know that the disease is characterized by several molecular and cellular abnormalities whose precise timing and relative roles in pathogenesis have yet to be understood. HD is triggered by the mutant protein, and both gain-of-function (of the mutant protein) and loss-of-function (of the normal protein) mechanisms are involved. Here we review the data that describe the emergence of the ancient huntingtin gene and of the polyglutamine trait during the last 800 million years of evolution. We focus on the known functions of wild-type huntingtin that are fundamental for the survival and functioning of the brain neurons that predominantly degenerate in HD. We summarize data indicating how the loss of these beneficial activities reduces the ability of these neurons to survive. We also review the different mechanisms by which the mutation in huntingtin causes toxicity. This may arise both from cell-autonomous processes and dysfunction of neuronal circuitries. We then focus on novel therapeutical targets and pathways and on the attractive option to counteract HD at its primary source, i.e., by blocking the production of the mutant protein. Strategies and technologies used to screen for candidate HD biomarkers and their potential application are presented. Furthermore, we discuss the opportunities offered by intracerebral cell transplantation and the likely need for these multiple routes into therapies to converge at some point as, ideally, one would wish to stop the disease process and, at the same time, possibly replace the damaged neurons.
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Affiliation(s)
- Chiara Zuccato
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milan, Italy
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80
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Abstract
Huntington's disease (HD) is caused by a CAG repeat expansion in exon 1 of the HD gene resulting in a long polyglutamine tract in the N-terminus of the protein huntingtin. Patients carrying the mutation display chorea in early stages followed by akinesia and sometimes dystonia in late stages. Other major symptoms include depression, anxiety, irritability or aggressive behavior, and apathy. Although many neuronal systems are affected, dysfunction and subsequent neurodegeneration in the basal ganglia and cortex are the most apparent pathologies. In HD, the primary hypothesis has been that there is an initial overactivity of glutamate neurotransmission that produces excitotoxicity followed by a series of complex changes that are different in the striatum and in the cortex. This review will focus on evidence for alterations in dopamine (DA)-glutamate interactions in HD, concentrating on the striatum and cortex. The most recent evidence points to decreases in DA and glutamate neurotransmission as the HD phenotype develops. However, there is some evidence for increased DA and glutamate functions that could be responsible for some of the early HD phenotype. Significant evidence indicates that glutamate and dopamine neurotransmission is affected in HD, compromising the fine balance in which DA modulates glutamate-induced excitation in the basal ganglia and cortex. Restoring the balance between glutamate and dopamine could be helpful to treat HD symptoms.
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Affiliation(s)
- Véronique M André
- Intellectual and Developmental Disabilities Research Center, Semel Institute, Department of Psychiatry and Biobehavioral Sciences, University of California, Los Angeles, USA. <>
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81
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Pandey M, Mohanakumar KP, Usha R. Mitochondrial functional alterations in relation to pathophysiology of Huntington’s disease. J Bioenerg Biomembr 2010; 42:217-26. [DOI: 10.1007/s10863-010-9288-5] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/19/2022]
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82
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Oliveira JMA. Nature and cause of mitochondrial dysfunction in Huntington's disease: focusing on huntingtin and the striatum. J Neurochem 2010; 114:1-12. [PMID: 20403078 DOI: 10.1111/j.1471-4159.2010.06741.x] [Citation(s) in RCA: 72] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Polyglutamine expansion mutation in huntingtin causes Huntington's disease (HD). How mutant huntingtin (mHtt) preferentially kills striatal neurons remains unknown. The link between mitochondrial dysfunction and HD pathogenesis stemmed from postmortem brain data and mitochondrial toxin models. Current evidence from genetic models, containing mHtt, supports mitochondrial dysfunction with yet uncertain nature and cause. Because mitochondria composition and function varies across tissues and cell-types, mitochondrial dysfunction in HD vulnerable striatal neurons may have distinctive features. This review focuses on mHtt and the striatum, integrating experimental evidence from patients, mice, primary cultures and striatal cell-lines. I address the nature (specific deficits) and cause (mechanisms linked to mHtt) of HD mitochondrial dysfunction, considering limitations of isolated vs. in situ mitochondria approaches, and the complications introduced by glia and glycolysis in brain and cell-culture studies. Current evidence relegates respiratory chain impairment to a late secondary event. Upstream events include defective mitochondrial calcium handling, ATP production and trafficking. Also, transcription abnormalities affecting mitochondria composition, reduced mitochondria trafficking to synapses, and direct interference with mitochondrial structures enriched in striatal neurons, are possible mechanisms by which mHtt amplifies striatal vulnerability. Insights from common neurodegenerative disorders with selective vulnerability and mitochondrial dysfunction (Alzheimer's and Parkinson's diseases) are also addressed.
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Affiliation(s)
- Jorge M A Oliveira
- REQUIMTE, Department of Drug Sciences, Faculty of Pharmacy, University of Porto, 4050-047 Porto, Portugal.
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Ferreira IL, Nascimento MV, Ribeiro M, Almeida S, Cardoso SM, Grazina M, Pratas J, Santos MJ, Januário C, Oliveira CR, Rego AC. Mitochondrial-dependent apoptosis in Huntington's disease human cybrids. Exp Neurol 2010; 222:243-55. [DOI: 10.1016/j.expneurol.2010.01.002] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Revised: 11/26/2009] [Accepted: 01/05/2010] [Indexed: 12/23/2022]
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Crosson CE, Mani SK, Husain S, Alsarraf O, Menick DR. Inhibition of histone deacetylase protects the retina from ischemic injury. Invest Ophthalmol Vis Sci 2010; 51:3639-45. [PMID: 20164449 DOI: 10.1167/iovs.09-4538] [Citation(s) in RCA: 89] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023] Open
Abstract
PURPOSE. The pathogenesis of retinal ischemia results from a series of events involving changes in gene expression and inflammatory cytokines. Protein acetylation is an essential mechanism in regulating transcriptional and inflammatory events. The purpose of this study was to investigate the neuroprotective action of the histone deacetylase (HDAC) inhibitor trichostatin A (TSA) in a retinal ischemic model. METHODS. To investigate whether HDAC inhibition can reduce ischemic injury, rats were treated with TSA (2.5 mg/kg intraperitoneally) twice daily on days 0, 1, 2, and 3. Seven days after ischemic injury, morphometric and electroretinographic (ERG) analyses were used to assess retinal structure and function. Western blot and immunohistochemical analyses were used to evaluate TSA-induced changes in histone-H3 acetylation and MMP secretion. RESULTS. In vehicle-treated animals, ERG a- and b-waves from ischemic eyes were significantly reduced compared with contralateral responses. In addition, histologic examination of these eyes revealed significant degeneration of inner retinal layers. In rats treated with TSA, amplitudes of ERG a- and b-waves from ischemic eyes were significantly increased, and normal inner retina morphology was preserved. Ischemia also increased the levels of retinal TNF-alpha, which was blocked by TSA treatment. In astrocyte cultures, the addition of TNF-alpha (10 ng/mL) stimulated the secretion of MMP-1 and MMP-3, which were blocked by TSA (100 nM). CONCLUSIONS. These studies provide the first evidence that suppressing HDAC activity can protect the retina from ischemic injury. This neuroprotective response is associated with the suppression of retinal TNF-alpha expression and signaling. The use of HDAC inhibitors may provide a novel treatment for ischemic retinal injury.
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Affiliation(s)
- Craig E Crosson
- Department of Ophthalmology, Storm Eye Institute, Gazes Cardiac Research Institute, Medical University of South Carolina, Charleston, South Carolina, USA.
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Williams BB, Li D, Wegrzynowicz M, Vadodaria BK, Anderson JG, Kwakye GF, Aschner M, Erikson KM, Bowman AB. Disease-toxicant screen reveals a neuroprotective interaction between Huntington's disease and manganese exposure. J Neurochem 2010; 112:227-37. [PMID: 19845833 PMCID: PMC3083829 DOI: 10.1111/j.1471-4159.2009.06445.x] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Recognizing the similarities between Huntington's disease (HD) pathophysiology and the neurotoxicology of various metals, we hypothesized that they may exhibit disease-toxicant interactions revealing cellular pathways underlying neurodegeneration. Here, we utilize metals and the STHdh mouse striatal cell line model of HD to perform a gene-environment interaction screen. We report that striatal cells expressing mutant Huntingtin exhibit elevated sensitivity to cadmium toxicity and resistance to manganese toxicity. This neuroprotective gene-environment interaction with manganese is highly specific, as it does not occur with iron, copper, zinc, cobalt, cadmium, lead, or nickel ions. Analysis of the Akt cell stress signaling pathway showed diminished activation with manganese exposure and elevated activation after cadmium exposure in the mutant cells. Direct examination of intracellular manganese levels found that mutant cells have a significant impairment in manganese accumulation. Furthermore, YAC128Q mice, a HD model, showed decreased total striatal manganese levels following manganese exposure relative to wild-type mice. Thus, this disease-toxicant interaction screen has revealed that expression of mutant Huntingtin results in heightened sensitivity to cadmium neurotoxicity and a selective impairment of manganese accumulation.
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Affiliation(s)
- B. Blairanne Williams
- Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
| | - Daphne Li
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
| | - Michal Wegrzynowicz
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
| | - Bhavin K. Vadodaria
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
| | - Joel G. Anderson
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC, USA, 27402-6107
| | - Gunnar F. Kwakye
- Neuroscience Graduate Program, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
| | - Michael Aschner
- Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Departments of Pediatrics and Pharmacology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
| | - Keith M. Erikson
- Department of Nutrition, University of North Carolina at Greensboro, Greensboro, NC, USA, 27402-6107
| | - Aaron B. Bowman
- Department of Neurology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Vanderbilt Kennedy Center for Research on Human Development, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Vanderbilt Brain Institute, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
- Center in Molecular Toxicology, Vanderbilt University Medical Center, Nashville, TN, USA, 37232
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Damiano M, Galvan L, Déglon N, Brouillet E. Mitochondria in Huntington's disease. Biochim Biophys Acta Mol Basis Dis 2010; 1802:52-61. [DOI: 10.1016/j.bbadis.2009.07.012] [Citation(s) in RCA: 213] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2009] [Revised: 07/31/2009] [Accepted: 07/31/2009] [Indexed: 11/16/2022]
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Huang HY, Lin SZ, Chen WF, Li KW, Kuo JS, Wang MJ. Urocortin modulates dopaminergic neuronal survival via inhibition of glycogen synthase kinase-3β and histone deacetylase. Neurobiol Aging 2009; 32:1662-77. [PMID: 19875195 DOI: 10.1016/j.neurobiolaging.2009.09.010] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2009] [Revised: 08/19/2009] [Accepted: 09/27/2009] [Indexed: 11/27/2022]
Abstract
Urocortin (UCN) is a member of the corticotropin-releasing hormone (CRH) family of neuropeptides that regulates stress responses. Although UCN is principally expressed in dopaminergic neurons in rat substantia nigra (SN), the function of UCN in modulating dopaminergic neuronal survival remains unclear. Using primary mesencephalic cultures, we demonstrated that dopaminergic neurons underwent spontaneous cell death when their age increased in culture. Treatment of mesencephalic cultures with UCN markedly prolonged the survival of dopaminergic neurons, whereas neutralization of UCN with anti-UCN antibody accelerated dopaminergic neurons degeneration. UCN increased intracellular cAMP levels followed by phosphorylating glycogen synthase kinase-3β (GSK-3β) on Ser9. Moreover, UCN directly inhibited the histone deacetylase (HDAC) activity and induced a robust increase in histone H3 acetylation levels. Using pharmacological approaches, we further demonstrated that inhibition of GSK-3β and HDAC contributes to UCN-mediated neuroprotection. These results suggest that dopaminergic neuron-derived UCN might be involved in an autocrine protective signaling mechanism.
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Affiliation(s)
- Hsin-Yi Huang
- Department of Research, Neuro-Medical Scientific Center, Buddhist Tzu Chi General Hospital, Hualien 970, Taiwan, ROC
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89
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Quintanilla RA, Johnson GV. Role of mitochondrial dysfunction in the pathogenesis of Huntington's disease. Brain Res Bull 2009; 80:242-7. [PMID: 19622387 PMCID: PMC2757461 DOI: 10.1016/j.brainresbull.2009.07.010] [Citation(s) in RCA: 133] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/30/2009] [Revised: 07/12/2009] [Accepted: 07/13/2009] [Indexed: 11/16/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder that is caused by a pathological expansion of CAG repeats within the gene encoding for a 350 kD protein called huntingtin. This polyglutamine expansion within huntingtin is the causative factor in the pathogenesis of HD, however the underlying mechanisms have not been fully elucidated. Nonetheless, it is becoming increasingly clear that alterations in mitochondrial function play key roles in the pathogenic processes in HD. The net result of these events is compromised energy metabolism and increased oxidative damage, which eventually contribute to neuronal dysfunction and death. Mitochondria from striatal cells of a genetically accurate model of HD take up less calcium and at a slower rate than mitochondria from striatal cells derived from normal mice. Further, respiration in mitochondria from these mutant huntingtin-expressing cells is inhibited at significantly lower calcium concentrations compared to mitochondria from wild-type cells. Considering these and other findings this review explores the evidence suggesting that mutant huntingtin, directly or indirectly impairs mitochondrial function, which compromises cytosolic and mitochondrial calcium homeostasis, and contributes to neuronal dysfunction and death in HD.
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Affiliation(s)
| | - Gail V.W. Johnson
- Department of Anesthesiology, University of Rochester, Rochester, NY, 14642-0002, USA
- Department of Pharmacology and Physiology, University of Rochester, Rochester, NY, 14642
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Reddy PH, Mao P, Manczak M. Mitochondrial structural and functional dynamics in Huntington's disease. BRAIN RESEARCH REVIEWS 2009; 61:33-48. [PMID: 19394359 PMCID: PMC2748129 DOI: 10.1016/j.brainresrev.2009.04.001] [Citation(s) in RCA: 130] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Subscribe] [Scholar Register] [Received: 03/25/2009] [Revised: 04/13/2009] [Accepted: 04/15/2009] [Indexed: 11/23/2022]
Abstract
Huntington's disease (HD) is an autosomal, dominantly inherited neurodegenerative disorder, characterized by chorea, involuntary movements, and cognitive impairments. Tremendous progress has been made since the discovery of HD gene in 1993, in terms of developing animal models to study the disease process, unraveling the expression and function of wild-type and mutant huntingtin (Htt) proteins in the central and peripheral nervous systems, and understanding expanded CAG repeat containing mutant Htt protein interactions with CNS proteins in the disease process. HD progression has been found to involve several pathomechanisms, including expanded CAG repeat protein interaction with other CNS proteins, transcriptional dysregulation, calcium dyshomeostasis, abnormal vesicle trafficking, and defective mitochondrial bioenergetics. Recent studies have found that mutant Htt is associated with mitochondria and causes mitochondrial structural changes, decreases mitochondrial trafficking, and impairs mitochondrial dynamics in the neurons affected by HD. This article discusses recent developments in HD research, with a particular focus on intracellular and intramitochondrial calcium influx, mitochondrial DNA defects, and mitochondrial structural and functional abnormalities in HD development and progression. Further, this article outlines the current status of mitochondrial therapeutics with a special reference to Dimebon.
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Affiliation(s)
- P Hemachandra Reddy
- Neurogenetics Laboratory, Neuroscience Division, Oregon National Primate Research Center, West Campus, Oregon Health and Science University, Beaverton, OR 97006, USA.
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The brain uncoupling protein UCP4 attenuates mitochondrial toxin-induced cell death: role of extracellular signal-regulated kinases in bioenergetics adaptation and cell survival. Neurotox Res 2009; 16:14-29. [PMID: 19526295 DOI: 10.1007/s12640-009-9039-8] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2008] [Revised: 01/11/2009] [Accepted: 02/27/2009] [Indexed: 12/25/2022]
Abstract
Increased bioenergetics demand can stimulate compensatory increases in glucose metabolism. We previously reported that neural cells expressing the brain uncoupling protein UCP4 exhibit enhanced dependency on glucose for support of cellular bioenergetics and survival. The switch from oxidative toward glycolytic metabolism reduces the production of toxic reactive oxygen species (ROS) and increases cellular resistance to toxicity induced by 3-nitropropionic acid, a mitochondrial complex II inhibitor that compromises cellular bioenergetics. In this study we elucidate the underlying mechanism whereby expression of UCP4 promotes bioenergetics adaptation and cell survival. We found that activation of extracellular signal-regulated kinases (ERKs) is necessary and sufficient for the increased dependency on glucose utilization. Pharmacological inhibition of ERKs not only abrogated bioenergetics adaptation but also reduced the activation of cAMP-responsive element-binding (CREB) protein suggesting that CREB protein signaling contributes in part to UCP4-dependent cell death rescue from 3-nitropropionic acid-induced toxicity. We also demonstrated that activation of ERKs by growth factors ameliorated the bioenergetics compromise and reduced cellular toxicity induced by 3-nitropropionic acid. Collectively, our results support the involvement of ERKs in UCP4 dependent bioenergetics adaptation and cell survival.
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92
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Oliveira JM, Gonçalves J. In Situ Mitochondrial Ca2+ Buffering Differences of Intact Neurons and Astrocytes from Cortex and Striatum. J Biol Chem 2009; 284:5010-20. [DOI: 10.1074/jbc.m807459200] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
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Kazantsev AG, Thompson LM. Therapeutic application of histone deacetylase inhibitors for central nervous system disorders. Nat Rev Drug Discov 2008; 7:854-68. [PMID: 18827828 DOI: 10.1038/nrd2681] [Citation(s) in RCA: 562] [Impact Index Per Article: 33.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
Histone deacetylases (HDACs)--enzymes that affect the acetylation status of histones and other important cellular proteins--have been recognized as potentially useful therapeutic targets for a broad range of human disorders. Pharmacological manipulations using small-molecule HDAC inhibitors--which may restore transcriptional balance to neurons, modulate cytoskeletal function, affect immune responses and enhance protein degradation pathways--have been beneficial in various experimental models of brain diseases. Although mounting data predict a therapeutic benefit for HDAC-based therapy, drug discovery and development of clinical candidates face significant challenges. Here, we summarize the current state of development of HDAC therapeutics and their application for the treatment of human brain disorders such as Rubinstein-Taybi syndrome, Rett syndrome, Friedreich's ataxia, Huntington's disease and multiple sclerosis.
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Affiliation(s)
- Aleksey G Kazantsev
- Harvard Medical School, Massachusetts General Hospital, Mass General Institute for Neurodegenerative Disease, Charlestown, Massachusetts 02129-4404, USA.
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Quintanilla RA, Jin YN, Fuenzalida K, Bronfman M, Johnson GVW. Rosiglitazone treatment prevents mitochondrial dysfunction in mutant huntingtin-expressing cells: possible role of peroxisome proliferator-activated receptor-gamma (PPARgamma) in the pathogenesis of Huntington disease. J Biol Chem 2008; 283:25628-25637. [PMID: 18640979 PMCID: PMC2533094 DOI: 10.1074/jbc.m804291200] [Citation(s) in RCA: 108] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2008] [Revised: 07/15/2008] [Indexed: 01/15/2023] Open
Abstract
Peroxisome proliferator-activated receptor-gamma (PPARgamma) is a member of the PPAR family of transcription factors. Synthetic PPARgamma agonists are used as oral anti-hyperglycemic drugs for the treatment of non-insulin-dependent diabetes. However, emerging evidence indicates that PPARgamma activators can also prevent or attenuate neurodegeneration. Given these previous findings, the focus of this report is on the potential neuroprotective role of PPARgamma activation in preventing the loss of mitochondrial function in Huntington disease (HD). For these studies we used striatal cells that express wild-type (STHdh(Q7/Q7)) or mutant (STHdh(Q111/Q111)) huntingtin protein at physiological levels. Treatment of mutant cells with thapsigargin resulted in a significant decrease in mitochondrial calcium uptake, an increase in reactive oxygen species production, and a significant decrease in mitochondrial membrane potential. PPARgamma activation by rosiglitazone prevented the mitochondrial dysfunction and oxidative stress that occurred when mutant striatal cells were challenged with pathological increases in calcium. The beneficial effects of rosiglitazone were likely mediated by activation of PPARgamma, as all protective effects were prevented by the PPARgamma antagonist GW9662. Additionally, the PPARgamma signaling pathway was significantly impaired in the mutant striatal cells with decreases in PPARgamma expression and reduced PPARgamma transcriptional activity. Treatment with rosiglitazone increased mitochondrial mass levels, suggesting a role for the PPARgamma pathway in mitochondrial function in striatal cells. Altogether, this evidence indicates that PPARgamma activation by rosiglitazone attenuates mitochondrial dysfunction in mutant huntingtin-expressing striatal cells, and this could be an important therapeutic avenue to ameliorate the mitochondrial dysfunction that occurs in HD.
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Affiliation(s)
| | - Youngnam N Jin
- Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642-0002
| | - Karen Fuenzalida
- Centro de Regulación Celular y Patologia Joaquín V. Luco and Millennium Institute for Fundamental and Applied Biology, Department of Cellular and Molecular Biology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 114-D, Chile
| | - Miguel Bronfman
- Centro de Regulación Celular y Patologia Joaquín V. Luco and Millennium Institute for Fundamental and Applied Biology, Department of Cellular and Molecular Biology, Facultad de Ciencias Biológicas, Pontificia Universidad Católica de Chile, Alameda 340, Santiago 114-D, Chile
| | - Gail V W Johnson
- Department of Anesthesiology, University of Rochester, Rochester, New York 14642; Department of Pharmacology and Physiology, University of Rochester, Rochester, New York 14642-0002.
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Seo H, Kim W, Isacson O. Compensatory changes in the ubiquitin-proteasome system, brain-derived neurotrophic factor and mitochondrial complex II/III in YAC72 and R6/2 transgenic mice partially model Huntington's disease patients. Hum Mol Genet 2008; 17:3144-53. [PMID: 18640989 DOI: 10.1093/hmg/ddn211] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/18/2022] Open
Abstract
Intraneuronal protein aggregates of the mutated huntingtin in Huntington's disease (HD) brains suggest an overload and/or dysfunction of the ubiquitin-proteasome system (UPS). There is a general inhibition of the UPS in many brain regions (cerebellum, cortex, substantia nigra and caudate-putamen) and skin fibroblasts from HD patients. In the current experiment, the widely used mutant huntingtin-exon 1 CAG repeat HD transgenic mice model (R6/2) (with 144 CAG repeat and exon 1) during late-stage pathology, had increases in proteasome activity in the striatum. However, this discrepancy with HD patient tissue was not apparent in the mutant CAG repeat huntingtin full-length HD (YAC72) transgenic mouse model during post-symptomatic and late-stage pathology, which then also showed UPS inhibition similar to HD patients' brains. In both types of HD model mice, we determined biochemical changes, including expression of brain-derived neurotrophic factor (BDNF) and mitochondrial complex II/III (MCII/III) activities related to HD pathology. We found increases of both BDNF expression, and MCII/III activities in YAC72 transgenic mice, and no change of BDNF expression in R6/2 mice. Our data show that extreme CAG repeat lengths in R6/2 mice is paradoxically associated with increased proteasome activity, probably as a cellular compensatory biochemical change in response to the underlying mutation. Changes in HD patients for UPS function, BDNF expression and MCII/III activity are only partially modeled in R6/2 and YAC72 mice, with the latter at 16 months of age being most congruent with the human disease.
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Affiliation(s)
- Hyemyung Seo
- Neuroregeneration Laboratories, Center for Neuroregeneration Research, McLean Hospital, Harvard MedicalSchool, 115 Mill Street, Belmont, MA 02478, USA
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Zhang H, Li Q, Graham RK, Slow E, Hayden MR, Bezprozvanny I. Full length mutant huntingtin is required for altered Ca2+ signaling and apoptosis of striatal neurons in the YAC mouse model of Huntington's disease. Neurobiol Dis 2008; 31:80-8. [PMID: 18502655 PMCID: PMC2528878 DOI: 10.1016/j.nbd.2008.03.010] [Citation(s) in RCA: 86] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2007] [Revised: 03/23/2008] [Accepted: 03/25/2008] [Indexed: 12/13/2022] Open
Abstract
Huntington's disease (HD) is caused by a progressive loss of striatal medium spiny neurons (MSN). The molecular trigger of HD is a polyglutamine expansion in the Huntingtin protein (Htt). The mutant Htt protein forms insoluble nuclear aggregates which have been proposed to play a key role in causing neuronal cell death in HD. Other lines of investigation suggest that expression of mutant Htt facilitates activity of the NR2B subtype of NMDA receptors and the type 1 inositol 1,4,5-trisphosphate receptors (InsP(3)R1), and that disturbed calcium (Ca(2+)) signaling causes apoptosis of MSNs in HD. The YAC128 transgenic HD mouse model expresses the full-length human Htt protein with 120Q CAG repeat expansion and displays an age-dependent loss of striatal neurons as seen in human HD brain. In contrast, the shortstop mice express an amino-terminal fragment of the mutant Htt protein (exons 1 and 2) and display no behavioral abnormalities or striatal neurodegeneration despite widespread formation of neuronal inclusions. Here we compared Ca(2+) signals in primary MSN neuronal cultures derived from YAC128 and shortstop mice to their wild-type non-transgenic littermates. Repetitive application of glutamate results in supranormal Ca(2+) responses in YAC128 MSNs, but not in shortstop MSNs. In addition, while currents mediated by the NR2B subtype of NMDA receptors were increased in YAC128 MSNs, currents in SS MSNs were found to be similar to WT. Furthermore, YAC128 MSNs were sensitized to glutamate-induced apoptosis. Consistent with these findings, we found that application of glutamate induced rapid loss of mitochondrial membrane potential in YAC128 MSNs. In contrast, SS MSNs do not show increased cell death postglutamate treatment nor accelerated loss of mitochondrial membrane potential following glutamate stimulation. Glutamate-induced loss of mitochondrial membrane potential in YAC128 MSNs could be prevented by inhibitors of NR2B NMDA receptors and mGluR1/5 receptors. Our results are consistent with the hypothesis that disturbed neuronal Ca(2+) signaling plays a significant role in the degeneration of MSN containing full-length mutant Htt(exp). Furthermore, the results obtained with neurons from shortstop mice provide additional evidence that not all fragments of mutant Htt(exp) are toxic to neurons.
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Affiliation(s)
- Hua Zhang
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA
| | - Qin Li
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA
| | - Rona K Graham
- Center for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Elizabeth Slow
- Center for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Michael R. Hayden
- Center for Molecular Medicine and Therapeutics, Department of Medical Genetics, Child and Family Research Institute, University of British Columbia, Vancouver, British Columbia, Canada
| | - Ilya Bezprozvanny
- Department of Physiology, University of Texas Southwestern Medical Center at Dallas, Dallas, Texas 75390, USA
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Zhang H, Das S, Li QZ, Dragatsis I, Repa J, Zeitlin S, Hajnóczky G, Bezprozvanny I. Elucidating a normal function of huntingtin by functional and microarray analysis of huntingtin-null mouse embryonic fibroblasts. BMC Neurosci 2008; 9:38. [PMID: 18412970 PMCID: PMC2377268 DOI: 10.1186/1471-2202-9-38] [Citation(s) in RCA: 24] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2007] [Accepted: 04/15/2008] [Indexed: 11/10/2022] Open
Abstract
Background The polyglutamine expansion in huntingtin (Htt) protein is a cause of Huntington's disease (HD). Htt is an essential gene as deletion of the mouse Htt gene homolog (Hdh) is embryonic lethal in mice. Therefore, in addition to elucidating the mechanisms responsible for polyQ-mediated pathology, it is also important to understand the normal function of Htt protein for both basic biology and for HD. Results To systematically search for a mouse Htt function, we took advantage of the Hdh +/- and Hdh-floxed mice and generated four mouse embryonic fibroblast (MEF) cells lines which contain a single copy of the Hdh gene (Hdh-HET) and four MEF lines in which the Hdh gene was deleted (Hdh-KO). The function of Htt in calcium (Ca2+) signaling was analyzed in Ca2+ imaging experiments with generated cell lines. We found that the cytoplasmic Ca2+ spikes resulting from the activation of inositol 1,4,5-trisphosphate receptor (InsP3R) and the ensuing mitochondrial Ca2+ signals were suppressed in the Hdh-KO cells when compared to Hdh-HET cells. Furthermore, in experiments with permeabilized cells we found that the InsP3-sensitivity of Ca2+ mobilization from endoplasmic reticulum was reduced in Hdh-KO cells. These results indicated that Htt plays an important role in modulating InsP3R-mediated Ca2+ signaling. To further evaluate function of Htt, we performed genome-wide transcription profiling of generated Hdh-HET and Hdh-KO cells by microarray. Our results revealed that 106 unique transcripts were downregulated by more than two-fold with p < 0.05 and 173 unique transcripts were upregulated at least two-fold with p < 0.05 in Hdh-KO cells when compared to Hdh-HET cells. The microarray results were confirmed by quantitative real-time PCR for a number of affected transcripts. Several signaling pathways affected by Hdh gene deletion were identified from annotation of the microarray results. Conclusion Functional analysis of generated Htt-null MEF cells revealed that Htt plays a direct role in Ca2+ signaling by modulating InsP3R sensitivity to InsP3. The genome-wide transcriptional profiling of Htt-null cells yielded novel and unique information about the normal function of Htt in cells, which may contribute to our understanding and treatment of HD.
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Affiliation(s)
- Hua Zhang
- Department of Physiology, UT Southwestern Medical Center at Dallas, Dallas, TX 75390, USA.
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Orr AL, Li S, Wang CE, Li H, Wang J, Rong J, Xu X, Mastroberardino PG, Greenamyre JT, Li XJ. N-terminal mutant huntingtin associates with mitochondria and impairs mitochondrial trafficking. J Neurosci 2008; 28:2783-92. [PMID: 18337408 PMCID: PMC2652473 DOI: 10.1523/jneurosci.0106-08.2008] [Citation(s) in RCA: 314] [Impact Index Per Article: 18.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2007] [Revised: 02/04/2008] [Accepted: 02/04/2008] [Indexed: 11/21/2022] Open
Abstract
Huntington's disease (HD) is caused by polyglutamine (polyQ) expansion in huntingtin (htt), a large (350 kDa) protein that localizes predominantly to the cytoplasm. Proteolytic cleavage of mutant htt yields polyQ-containing N-terminal fragments that are prone to misfolding and aggregation. Disease progression in HD transgenic models correlates with age-related accumulation of soluble and aggregated forms of N-terminal mutant htt fragments, suggesting that multiple forms of mutant htt are involved in the selective neurodegeneration in HD. Although mitochondrial dysfunction is implicated in the pathogenesis of HD, it remains unclear which forms of cytoplasmic mutant htt associate with mitochondria to affect their function. Here we demonstrate that specific N-terminal mutant htt fragments associate with mitochondria in Hdh(CAG)150 knock-in mouse brain and that this association increases with age. The interaction between soluble N-terminal mutant htt and mitochondria interferes with the in vitro association of microtubule-based transport proteins with mitochondria. Mutant htt reduces the distribution and transport rate of mitochondria in the processes of cultured neuronal cells. Reduced ATP level was also found in the synaptosomal fraction isolated from Hdh(CAG)150 knock-in mouse brain. These findings suggest that specific N-terminal mutant htt fragments, before the formation of aggregates, can impair mitochondrial function directly and that this interaction may be a novel target for therapeutic strategies in HD.
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Affiliation(s)
- Adam L. Orr
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Shihua Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Chuan-En Wang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - He Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
- Division of Histology and Embryology, Tongji Medical College, Huazhong University of Science and Technology, Wuhan 430030, People's Republic of China, and
| | - Jianjun Wang
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Juan Rong
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Xingshun Xu
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
| | - Pier Giorgio Mastroberardino
- Pittsburgh Institute for Neurodegenerative Diseases and the Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - J. Timothy Greenamyre
- Pittsburgh Institute for Neurodegenerative Diseases and the Department of Neurology, University of Pittsburgh, Pittsburgh, Pennsylvania 15260
| | - Xiao-Jiang Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, Georgia 30322
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Brioschi A, Zara GP, Calderoni S, Gasco MR, Mauro A. Cholesterylbutyrate solid lipid nanoparticles as a butyric acid prodrug. Molecules 2008; 13:230-54. [PMID: 18305415 PMCID: PMC6245427 DOI: 10.3390/molecules13020230] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2008] [Revised: 01/31/2008] [Accepted: 02/01/2008] [Indexed: 12/25/2022] Open
Abstract
Cholesterylbutyrate (Chol-but) was chosen as a prodrug of butyric acid. Butyrate is not often used in vivo because its half-life is very short and therefore too large amounts of the drug would be necessary for its efficacy. In the last few years butyric acid's anti-inflammatory properties and its inhibitory activity towards histone deacetylases have been widely studied, mainly in vitro. Solid Lipid Nanoparticles (SLNs), whose lipid matrix is Chol-but, were prepared to evaluate the delivery system of Chol-but as a prodrug and to test its efficacy in vitro and in vivo. Chol-but SLNs were prepared using the microemulsion method; their average diameter is on the order of 100-150 nm and their shape is spherical. The antineoplastic effects of Chol-but SLNs were assessed in vitro on different cancer cell lines and in vivo on a rat intracerebral glioma model. The anti-inflammatory activity was evaluated on adhesion of polymorphonuclear cells to vascular endothelial cells. In the review we will present data on Chol-but SLNs in vitro and in vivo experiments, discussing the possible utilisation of nanoparticles for the delivery of prodrugs for neoplastic and chronic inflammatory diseases.
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Affiliation(s)
- Andrea Brioschi
- Istituto Auxologico Italiano, IRCCS - Department of Neurology - Ospedale S. Giuseppe, Piancavallo, PO. Box 1 - 28921 Verbania, Italy.
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