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Burtscher J, Strasser B, Pepe G, Burtscher M, Kopp M, Di Pardo A, Maglione V, Khamoui AV. Brain-Periphery Interactions in Huntington's Disease: Mediators and Lifestyle Interventions. Int J Mol Sci 2024; 25:4696. [PMID: 38731912 PMCID: PMC11083237 DOI: 10.3390/ijms25094696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2024] [Revised: 04/22/2024] [Accepted: 04/23/2024] [Indexed: 05/13/2024] Open
Abstract
Prominent pathological features of Huntington's disease (HD) are aggregations of mutated Huntingtin protein (mHtt) in the brain and neurodegeneration, which causes characteristic motor (such as chorea and dystonia) and non-motor symptoms. However, the numerous systemic and peripheral deficits in HD have gained increasing attention recently, since those factors likely modulate disease progression, including brain pathology. While whole-body metabolic abnormalities and organ-specific pathologies in HD have been relatively well described, the potential mediators of compromised inter-organ communication in HD have been insufficiently characterized. Therefore, we applied an exploratory literature search to identify such mediators. Unsurprisingly, dysregulation of inflammatory factors, circulating mHtt, and many other messenger molecules (hormones, lipids, RNAs) were found that suggest impaired inter-organ communication, including of the gut-brain and muscle-brain axis. Based on these findings, we aimed to assess the risks and potentials of lifestyle interventions that are thought to improve communication across these axes: dietary strategies and exercise. We conclude that appropriate lifestyle interventions have great potential to reduce symptoms and potentially modify disease progression (possibly via improving inter-organ signaling) in HD. However, impaired systemic metabolism and peripheral symptoms warrant particular care in the design of dietary and exercise programs for people with HD.
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Affiliation(s)
- Johannes Burtscher
- Institute of Sport Sciences, University of Lausanne, 1015 Lausanne, Switzerland
| | - Barbara Strasser
- Ludwig Boltzmann Institute for Rehabilitation Research, 1100 Vienna, Austria;
- Faculty of Medicine, Sigmund Freud Private University, 1020 Vienna, Austria
| | - Giuseppe Pepe
- IRCCS Neuromed, 86077 Pozzilli, Italy; (G.P.); (A.D.P.); (V.M.)
| | - Martin Burtscher
- Department of Sport Science, University of Innsbruck, 6020 Innsbruck, Austria; (M.B.); (M.K.)
| | - Martin Kopp
- Department of Sport Science, University of Innsbruck, 6020 Innsbruck, Austria; (M.B.); (M.K.)
| | - Alba Di Pardo
- IRCCS Neuromed, 86077 Pozzilli, Italy; (G.P.); (A.D.P.); (V.M.)
| | | | - Andy V. Khamoui
- Department of Exercise Science and Health Promotion, Florida Atlantic University, Boca Raton, FL 33458, USA;
- Institute for Human Health and Disease Intervention, Florida Atlantic University, Jupiter, FL 33458, USA
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2
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Baev AY, Vinokurov AY, Potapova EV, Dunaev AV, Angelova PR, Abramov AY. Mitochondrial Permeability Transition, Cell Death and Neurodegeneration. Cells 2024; 13:648. [PMID: 38607087 PMCID: PMC11011324 DOI: 10.3390/cells13070648] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2024] [Revised: 03/27/2024] [Accepted: 04/06/2024] [Indexed: 04/13/2024] Open
Abstract
Neurodegenerative diseases are chronic conditions occurring when neurons die in specific brain regions that lead to loss of movement or cognitive functions. Despite the progress in understanding the mechanisms of this pathology, currently no cure exists to treat these types of diseases: for some of them the only help is alleviating the associated symptoms. Mitochondrial dysfunction has been shown to be involved in the pathogenesis of most the neurodegenerative disorders. The fast and transient permeability of mitochondria (the mitochondrial permeability transition, mPT) has been shown to be an initial step in the mechanism of apoptotic and necrotic cell death, which acts as a regulator of tissue regeneration for postmitotic neurons as it leads to the irreparable loss of cells and cell function. In this study, we review the role of the mitochondrial permeability transition in neuronal death in major neurodegenerative diseases, covering the inductors of mPTP opening in neurons, including the major ones-free radicals and calcium-and we discuss perspectives and difficulties in the development of a neuroprotective strategy based on the inhibition of mPTP in neurodegenerative disorders.
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Affiliation(s)
- Artyom Y. Baev
- Laboratory of Experimental Biophysics, Centre for Advanced Technologies, Tashkent 100174, Uzbekistan;
- Department of Biophysics, Faculty of Biology, National University of Uzbekistan, Tashkent 100174, Uzbekistan
| | - Andrey Y. Vinokurov
- Cell Physiology and Pathology Laboratory, Orel State University, Orel 302026, Russia; (A.Y.V.); (E.V.P.); (A.V.D.)
| | - Elena V. Potapova
- Cell Physiology and Pathology Laboratory, Orel State University, Orel 302026, Russia; (A.Y.V.); (E.V.P.); (A.V.D.)
| | - Andrey V. Dunaev
- Cell Physiology and Pathology Laboratory, Orel State University, Orel 302026, Russia; (A.Y.V.); (E.V.P.); (A.V.D.)
| | - Plamena R. Angelova
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK;
| | - Andrey Y. Abramov
- Department of Clinical and Movement Neurosciences, UCL Queen Square Institute of Neurology, Queen Square, London WC1N 3BG, UK;
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Age-associated alterations of brain mitochondria energetics. Biochem Biophys Res Commun 2023; 643:1-7. [PMID: 36584587 DOI: 10.1016/j.bbrc.2022.12.070] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2022] [Revised: 11/28/2022] [Accepted: 12/22/2022] [Indexed: 12/25/2022]
Abstract
The study aimed to explore the role of age-associated elevated cytosolic Ca2+ in changes of brain mitochondria energetic processes. Two groups of rats, young adults (4 months) and advanced old (24 months), were evaluated for potential alterations of mitochondrial parameters, the oxidative phosphorylation (OxPhos), membrane potential, calcium retention capacity, activity of glutamate/aspartate carrier (aralar), and ROS formation. We demonstrated that the brain mitochondria of older animals have a lower resistance to Ca2+ stress with resulting consequences. The suppressed complex I OxPhos and decreased membrane potential were accompanied by reduction of the Ca2+ threshold required for induction of mPTP. The Ca2+ binding sites of mitochondrial aralar mediated a lower activity of old brain mitochondria. The altered interaction between aralar and mPTP may underlie mitochondrial dysregulation leading to energetic depression during aging. At the advanced stages of aging, the declined metabolism is accompanied by the diminished oxidative background.
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Kim H, Gomez-Pastor R. HSF1 and Its Role in Huntington's Disease Pathology. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2023; 1410:35-95. [PMID: 36396925 DOI: 10.1007/5584_2022_742] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
PURPOSE OF REVIEW Heat shock factor 1 (HSF1) is the master transcriptional regulator of the heat shock response (HSR) in mammalian cells and is a critical element in maintaining protein homeostasis. HSF1 functions at the center of many physiological processes like embryogenesis, metabolism, immune response, aging, cancer, and neurodegeneration. However, the mechanisms that allow HSF1 to control these different biological and pathophysiological processes are not fully understood. This review focuses on Huntington's disease (HD), a neurodegenerative disease characterized by severe protein aggregation of the huntingtin (HTT) protein. The aggregation of HTT, in turn, leads to a halt in the function of HSF1. Understanding the pathways that regulate HSF1 in different contexts like HD may hold the key to understanding the pathomechanisms underlying other proteinopathies. We provide the most current information on HSF1 structure, function, and regulation, emphasizing HD, and discussing its potential as a biological target for therapy. DATA SOURCES We performed PubMed search to find established and recent reports in HSF1, heat shock proteins (Hsp), HD, Hsp inhibitors, HSF1 activators, and HSF1 in aging, inflammation, cancer, brain development, mitochondria, synaptic plasticity, polyglutamine (polyQ) diseases, and HD. STUDY SELECTIONS Research and review articles that described the mechanisms of action of HSF1 were selected based on terms used in PubMed search. RESULTS HSF1 plays a crucial role in the progression of HD and other protein-misfolding related neurodegenerative diseases. Different animal models of HD, as well as postmortem brains of patients with HD, reveal a connection between the levels of HSF1 and HSF1 dysfunction to mutant HTT (mHTT)-induced toxicity and protein aggregation, dysregulation of the ubiquitin-proteasome system (UPS), oxidative stress, mitochondrial dysfunction, and disruption of the structural and functional integrity of synaptic connections, which eventually leads to neuronal loss. These features are shared with other neurodegenerative diseases (NDs). Currently, several inhibitors against negative regulators of HSF1, as well as HSF1 activators, are developed and hold promise to prevent neurodegeneration in HD and other NDs. CONCLUSION Understanding the role of HSF1 during protein aggregation and neurodegeneration in HD may help to develop therapeutic strategies that could be effective across different NDs.
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Affiliation(s)
- Hyuck Kim
- Department of Neuroscience, School of Medicine, University of Minnesota, Minneapolis, MN, USA
| | - Rocio Gomez-Pastor
- Department of Neuroscience, School of Medicine, University of Minnesota, Minneapolis, MN, USA.
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Dhankhar J, Shrivastava A, Agrawal N. Amendment of Altered Immune Response by Curcumin in Drosophila Model of Huntington's Disease. J Huntingtons Dis 2023; 12:335-354. [PMID: 37781812 DOI: 10.3233/jhd-230595] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/03/2023]
Abstract
BACKGROUND Though primarily classified as a brain disorder, surplus studies direct Huntington's disease (HD) to be a multi-system disorder affecting various tissues and organs, thus affecting overall physiology of host. Recently, we have reported that neuronal expression of mutant huntingtin induces immune dysregulation in Drosophila and may pose chronic threat to challenged individuals. Therefore, we tested the polyphenolic compound curcumin to circumvent the impact of immune dysregulation in Drosophila model of HD. OBJECTIVE The present study examined the molecular basis underlying immune derangements and immunomodulatory potential of curcumin in HD. METHODS UAS-GAL4 system was used to imitate the HD symptoms in Drosophila, and the desired female progenies (elav > Httex1pQ25; control and elav > Httex1pQ93; diseased) were cultured on food mixed without and with 10 μM concentration of curcumin since early development. Effect of curcumin supplementation was investigated by monitoring the hemocytes' count and their functional abilities in diseased condition. Reactive oxygen species (ROS) level in cells was assessed by DHE staining and mitochondrial dysfunction was assessed by CMXros red dye. In addition, transcript levels of pro-inflammatory cytokines and anti-microbial peptides were monitored by qRT-PCR. RESULTS We found that curcumin supplementation commendably reduced higher crystal cell count and phenoloxidase activity in diseased flies. Interestingly, curcumin significantly managed altered plasmatocytes count, improved their phagocytic activity by upregulating the expression of key phagocytic receptors in HD condition. Moreover, substantial alleviation of ROS levels and mitochondria dysfunction was observed in plasmatocytes of diseased flies upon curcumin supplementation. Furthermore, curcumin administration effectively attenuated transcriptional expression of pro-inflammatory cytokines and AMPs in diseased flies. CONCLUSIONS Our results indicate that curcumin efficiently attenuates immune derangements in HD flies and may prove beneficial in alleviating complexities associated with HD.
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Affiliation(s)
- Jyoti Dhankhar
- Department of Zoology, University of Delhi, Delhi, India
| | | | - Namita Agrawal
- Department of Zoology, University of Delhi, Delhi, India
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Tomczyk M, Braczko A, Mierzejewska P, Podlacha M, Krol O, Jablonska P, Jedrzejewska A, Pierzynowska K, Wegrzyn G, Slominska EM, Smolenski RT. Rosiglitazone Ameliorates Cardiac and Skeletal Muscle Dysfunction by Correction of Energetics in Huntington’s Disease. Cells 2022; 11:cells11172662. [PMID: 36078070 PMCID: PMC9454785 DOI: 10.3390/cells11172662] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/02/2022] [Revised: 08/23/2022] [Accepted: 08/24/2022] [Indexed: 11/16/2022] Open
Abstract
Huntington’s disease (HD) is a rare neurodegenerative disease that is accompanied by skeletal muscle atrophy and cardiomyopathy. Tissues affected by HD (central nervous system [CNS], skeletal muscle, and heart) are known to suffer from deteriorated cellular energy metabolism that manifests already at presymptomatic stages. This work aimed to test the effects of peroxisome proliferator-activated receptor (PPAR)-γ agonist—rosiglitazone on grip strength and heart function in an experimental HD model—on R6/1 mice and to address the mechanisms. We noted that rosiglitazone treatment lead to improvement of R6/1 mice grip strength and cardiac mechanical function. It was accompanied by an enhancement of the total adenine nucleotides pool, increased glucose oxidation, changes in mitochondrial number (indicated as increased citric synthase activity), and reduction in mitochondrial complex I activity. These metabolic changes were supported by increased total antioxidant status in HD mice injected with rosiglitazone. Correction of energy deficits with rosiglitazone was further indicated by decreased accumulation of nucleotide catabolites in HD mice serum. Thus, rosiglitazone treatment may not only delay neurodegeneration but also may ameliorate cardio- and myopathy linked to HD by improvement of cellular energetics.
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Affiliation(s)
- Marta Tomczyk
- Department of Biochemistry, Medical University of Gdansk, 80-211 Gdansk, Poland
- Department of Molecular Biology, University of Gdansk, 80-308 Gdansk, Poland
- Correspondence: (M.T.); (R.T.S.)
| | - Alicja Braczko
- Department of Biochemistry, Medical University of Gdansk, 80-211 Gdansk, Poland
| | | | - Magdalena Podlacha
- Department of Molecular Biology, University of Gdansk, 80-308 Gdansk, Poland
| | - Oliwia Krol
- Department of Biochemistry, Medical University of Gdansk, 80-211 Gdansk, Poland
| | - Patrycja Jablonska
- Department of Biochemistry, Medical University of Gdansk, 80-211 Gdansk, Poland
| | - Agata Jedrzejewska
- Department of Biochemistry, Medical University of Gdansk, 80-211 Gdansk, Poland
| | - Karolina Pierzynowska
- Department of Biochemistry, Medical University of Gdansk, 80-211 Gdansk, Poland
- Department of Molecular Biology, University of Gdansk, 80-308 Gdansk, Poland
| | - Grzegorz Wegrzyn
- Department of Molecular Biology, University of Gdansk, 80-308 Gdansk, Poland
| | - Ewa M. Slominska
- Department of Biochemistry, Medical University of Gdansk, 80-211 Gdansk, Poland
| | - Ryszard T. Smolenski
- Department of Biochemistry, Medical University of Gdansk, 80-211 Gdansk, Poland
- Correspondence: (M.T.); (R.T.S.)
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Effects of Exercise on Skeletal Muscle Pathophysiology in Huntington's Disease. J Funct Morphol Kinesiol 2022; 7:jfmk7020040. [PMID: 35645302 PMCID: PMC9149967 DOI: 10.3390/jfmk7020040] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 05/05/2022] [Accepted: 05/09/2022] [Indexed: 11/17/2022] Open
Abstract
Huntington's disease (HD) is a rare, hereditary, and progressive neurodegenerative disease, characterized by involuntary choreatic movements with cognitive and behavioral disturbances. In order to mitigate impairments in motor function, physical exercise was integrated in HD rehabilitative interventions, showing to be a powerful tool to ameliorate the quality of life of HD-affected patients. This review aims to describe the effects of physical exercise on HD-related skeletal muscle disorders in both murine and human models. We performed a literature search using PubMed, Scopus, and Web of Science databases on the role of physical activity in mouse models of HD and human patients. Fifteen publications fulfilled the criteria and were included in the review. Studies performed on mouse models showed a controversial role played by exercise, whereas in HD-affected patients, physical activity appeared to have positive effects on gait, motor function, UHDMRS scale, cognitive function, quality of life, postural stability, total body mass, fatty acid oxidative capacity, and VO2 max. Physical activity seems to be feasible, safe, and effective for HD patients. However, further studies with longer follow-up and larger cohorts of patients will be needed to draw firm conclusions on the positive effects of exercise for HD patients.
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8
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Interaction of Mitochondrial Calcium and ROS in Neurodegeneration. Cells 2022; 11:cells11040706. [PMID: 35203354 PMCID: PMC8869783 DOI: 10.3390/cells11040706] [Citation(s) in RCA: 46] [Impact Index Per Article: 23.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/21/2022] [Revised: 02/05/2022] [Accepted: 02/14/2022] [Indexed: 02/06/2023] Open
Abstract
Neurodegenerative disorders are currently incurable devastating diseases which are characterized by the slow and progressive loss of neurons in specific brain regions. Progress in the investigation of the mechanisms of these disorders helped to identify a number of genes associated with familial forms of these diseases and a number of toxins and risk factors which trigger sporadic and toxic forms of these diseases. Recently, some similarities in the mechanisms of neurodegenerative diseases were identified, including the involvement of mitochondria, oxidative stress, and the abnormality of Ca2+ signaling in neurons and astrocytes. Thus, mitochondria produce reactive oxygen species during metabolism which play a further role in redox signaling, but this may also act as an additional trigger for abnormal mitochondrial calcium handling, resulting in mitochondrial calcium overload. Combinations of these factors can be the trigger of neuronal cell death in some pathologies. Here, we review the latest literature on the crosstalk of reactive oxygen species and Ca2+ in brain mitochondria in physiology and beyond, considering how changes in mitochondrial metabolism or redox signaling can convert this interaction into a pathological event.
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Chuang CL, Demontis F. Systemic manifestation and contribution of peripheral tissues to Huntington's disease pathogenesis. Ageing Res Rev 2021; 69:101358. [PMID: 33979693 DOI: 10.1016/j.arr.2021.101358] [Citation(s) in RCA: 22] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 03/23/2021] [Accepted: 05/07/2021] [Indexed: 12/11/2022]
Abstract
Huntington disease (HD) is an autosomal dominant neurodegenerative disease that is caused by expansion of cytosine/adenosine/guanine repeats in the huntingtin (HTT) gene, which leads to a toxic, aggregation-prone, mutant HTT-polyQ protein. Beyond the well-established mechanisms of HD progression in the central nervous system, growing evidence indicates that also peripheral tissues are affected in HD and that systemic signaling originating from peripheral tissues can influence the progression of HD in the brain. Herein, we review the systemic manifestation of HD in peripheral tissues, and the impact of systemic signaling on HD pathogenesis. Mutant HTT induces a body wasting syndrome (cachexia) primarily via its activity in skeletal muscle, bone, adipose tissue, and heart. Additional whole-organism effects induced by mutant HTT include decline in systemic metabolic homeostasis, which stems from derangement of pancreas, liver, gut, hypothalamic-pituitary-adrenal axis, and circadian functions. In addition to spreading via the bloodstream and a leaky blood brain barrier, HTT-polyQ may travel long distance via its uptake by neurons and its axonal transport from the peripheral to the central nervous system. Lastly, signaling factors that are produced and/or secreted in response to therapeutic interventions such as exercise or in response to mutant HTT activity in peripheral tissues may impact HD. In summary, these studies indicate that HD is a systemic disease that is influenced by intertissue signaling and by the action of pathogenic HTT in peripheral tissues. We propose that treatment strategies for HD should include the amelioration of HD symptoms in peripheral tissues. Moreover, harnessing signaling between peripheral tissues and the brain may provide a means for reducing HD progression in the central nervous system.
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Singh A, Agrawal N. Deciphering the key mechanisms leading to alteration of lipid metabolism in Drosophila model of Huntington's disease. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166127. [PMID: 33722743 DOI: 10.1016/j.bbadis.2021.166127] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2020] [Revised: 01/27/2021] [Accepted: 03/03/2021] [Indexed: 12/19/2022]
Abstract
Huntington's disease (HD) is an inherited, progressively debilitating disorder marked by prominent degeneration in striatal and cortical brain regions. HD is caused by (CAG)n repeat expansion in huntingtin (HTT) gene that translates into a mutant form of the ubiquitously present Huntingtin (HTT) protein. Extensive metabolic dysfunction coexisting with overt neuropathies has been evidenced in clinical and experimental settings of HD. Body weight loss despite normal to high caloric intake remains a critical determinant of the disease progression and a challenge for therapeutic interventions. In the present study, we intended to monitor the cellular and molecular perturbations in Drosophila, caused by pan-neuronal expression of mHTT (mutant Huntingtin) protein. We found aberrant transcription profile of key lipolytic and lipogenic genes in whole-body of the fly with disease progression. Interestingly, fatbody undergoes extensive alteration of vital cellular processes and eventually surrenders to increased apoptotic cell death in terminal stage of the disease. Extensive mitochondrial dysfunction from early disease stage along with calcium derangement at terminal stage were observed in fatbody, which contribute to its deteriorating integrity. All the mechanisms were monitored progressively, at different disease stages, and many alterations were documented in the early stage itself. Our study hence provides insight into the mechanisms through which neuronal expression of mHTT might be inflicting the profound systemic effects, specifically on lipid metabolism, and may open new therapeutic avenues for alleviation of the multidimensional disease.
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Affiliation(s)
- Akanksha Singh
- Department of Zoology, University of Delhi, Delhi 110007, India
| | - Namita Agrawal
- Department of Zoology, University of Delhi, Delhi 110007, India.
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Romer SH, Metzger S, Peraza K, Wright MC, Jobe DS, Song LS, Rich MM, Foy BD, Talmadge RJ, Voss AA. A mouse model of Huntington's disease shows altered ultrastructure of transverse tubules in skeletal muscle fibers. J Gen Physiol 2021; 153:211860. [PMID: 33683318 PMCID: PMC7931643 DOI: 10.1085/jgp.202012637] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2020] [Revised: 11/05/2020] [Accepted: 01/26/2021] [Indexed: 12/12/2022] Open
Abstract
Huntington’s disease (HD) is a fatal and progressive condition with severe debilitating motor defects and muscle weakness. Although classically recognized as a neurodegenerative disorder, there is increasing evidence of cell autonomous toxicity in skeletal muscle. We recently demonstrated that skeletal muscle fibers from the R6/2 model mouse of HD have a decrease in specific membrane capacitance, suggesting a loss of transverse tubule (t-tubule) membrane in R6/2 muscle. A previous report also indicated that Cav1.1 current was reduced in R6/2 skeletal muscle, suggesting defects in excitation–contraction (EC) coupling. Thus, we hypothesized that a loss and/or disruption of the skeletal muscle t-tubule system contributes to changes in EC coupling in R6/2 skeletal muscle. We used live-cell imaging with multiphoton confocal microscopy and transmission electron microscopy to assess the t-tubule architecture in late-stage R6/2 muscle and found no significant differences in the t-tubule system density, regularity, or integrity. However, electron microscopy images revealed that the cross-sectional area of t-tubules at the triad were 25% smaller in R6/2 compared with age-matched control skeletal muscle. Computer simulation revealed that the resulting decrease in the R6/2 t-tubule luminal conductance contributed to, but did not fully explain, the reduced R6/2 membrane capacitance. Analyses of bridging integrator-1 (Bin1), which plays a primary role in t-tubule formation, revealed decreased Bin1 protein levels and aberrant splicing of Bin1 mRNA in R6/2 muscle. Additionally, the distance between the t-tubule and sarcoplasmic reticulum was wider in R6/2 compared with control muscle, which was associated with a decrease in junctophilin 1 and 2 mRNA levels. Altogether, these findings can help explain dysregulated EC coupling and motor impairment in Huntington’s disease.
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Affiliation(s)
- Shannon H Romer
- Department of Biological Sciences, Wright State University, Dayton, OH.,Odyssey Systems, Environmental Health Effects Laboratory, Navy Medical Research Unit, Dayton, Wright-Patterson Air Force Base, Dayton, OH
| | - Sabrina Metzger
- Department of Neuroscience, Cell Biology, and Physiology, Wright State University, Dayton, OH
| | - Kristiana Peraza
- Department of Biological Sciences, California State Polytechnic University, Pomona, Pomona, CA
| | - Matthew C Wright
- Department of Biological Sciences, California State Polytechnic University, Pomona, Pomona, CA
| | - D Scott Jobe
- Department of Biological Sciences, Wright State University, Dayton, OH
| | - Long-Sheng Song
- Division of Cardiovascular Medicine, Department of Internal Medicine, Abboud Cardiovascular Research Center, University of Iowa Carver College of Medicine, Iowa City, IA
| | - Mark M Rich
- Department of Neuroscience, Cell Biology, and Physiology, Wright State University, Dayton, OH
| | - Brent D Foy
- Department of Physics, Wright State University, Dayton, OH
| | - Robert J Talmadge
- Department of Biological Sciences, California State Polytechnic University, Pomona, Pomona, CA
| | - Andrew A Voss
- Department of Biological Sciences, Wright State University, Dayton, OH
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12
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Bozzi M, Sciandra F. Molecular Mechanisms Underlying Muscle Wasting in Huntington's Disease. Int J Mol Sci 2020; 21:ijms21218314. [PMID: 33167595 PMCID: PMC7664236 DOI: 10.3390/ijms21218314] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/24/2020] [Revised: 11/03/2020] [Accepted: 11/03/2020] [Indexed: 12/13/2022] Open
Abstract
Huntington’s disease (HD) is an autosomal dominant neurodegenerative disorder caused by pathogenic expansions of the triplet cytosine-adenosine-guanosine (CAG) within the Huntingtin gene. These expansions lead to a prolongation of the poly-glutamine stretch at the N-terminus of Huntingtin causing protein misfolding and aggregation. Huntingtin and its pathological variants are widely expressed, but the central nervous system is mainly affected, as proved by the wide spectrum of neurological symptoms, including behavioral anomalies, cognitive decline and motor disorders. Other hallmarks of HD are loss of body weight and muscle atrophy. This review highlights some key elements that likely provide a major contribution to muscle atrophy, namely, alteration of the transcriptional processes, mitochondrial dysfunction, which is strictly correlated to loss of energy homeostasis, inflammation, apoptosis and defects in the processes responsible for the protein quality control. The improvement of muscular symptoms has proven to slow the disease progression and extend the life span of animal models of HD, underlining the importance of a deep comprehension of the molecular mechanisms driving deterioration of muscular tissue.
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Affiliation(s)
- Manuela Bozzi
- Dipartimento Universitario di Scienze Biotecnologiche di Base, Cliniche Intensivologiche e Perioperatorie, Sezione di Biochimica e Biochimica Clinica, Università Cattolica del Sacro Cuore di Roma, Largo F. Vito 1, 00168 Roma, Italy
- Istituto di Scienze e Tecnologie Chimiche “Giulio Natta”– SCITEC Sede di Roma, Largo F. Vito 1, 00168 Roma, Italy;
- Correspondence:
| | - Francesca Sciandra
- Istituto di Scienze e Tecnologie Chimiche “Giulio Natta”– SCITEC Sede di Roma, Largo F. Vito 1, 00168 Roma, Italy;
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Abstract
Huntington's disease (HD) is a fatal, inherited neurodegenerative disorder caused by a mutation in the huntingtin gene (HTT). While mutant HTT is present ubiquitously throughout life, HD onset typically occurs in mid-life, suggesting that aging may play an active role in pathogenesis. Cellular aging is defined as the slow decline in stress resistance and accumulation of damage over time. While different cells and tissues can age at different rates, 9 hallmarks of aging have emerged to better define the cellular aging process. Strikingly, many of the hallmarks of aging are also hallmarks of HD pathology. Models of HD and HD patients possess markers of accelerated aging, and processes that decline during aging also decline at a more rapid rate in HD, further implicating the role of aging in HD pathogenesis. Furthermore, accelerating aging in HD mouse and patient-derived neurons unmasks HD-specific phenotypes, suggesting an active role for the aging process in the onset and progression of HD. Here, we review the overlap between the hallmarks of aging and HD and discuss how aging may contribute to pathogenesis in HD.
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Affiliation(s)
- Emily Machiela
- University of Central Florida, College of Medicine, Burnett School of Biomedical Sciences, Orlando, FL, USA
| | - Amber L. Southwell
- University of Central Florida, College of Medicine, Burnett School of Biomedical Sciences, Orlando, FL, USA
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Rodinova M, Krizova J, Stufkova H, Bohuslavova B, Askeland G, Dosoudilova Z, Juhas S, Juhasova J, Ellederova Z, Zeman J, Eide L, Motlik J, Hansikova H. Deterioration of mitochondrial bioenergetics and ultrastructure impairment in skeletal muscle of a transgenic minipig model in the early stages of Huntington's disease. Dis Model Mech 2019; 12:dmm.038737. [PMID: 31278192 PMCID: PMC6679385 DOI: 10.1242/dmm.038737] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/03/2019] [Accepted: 06/18/2019] [Indexed: 01/08/2023] Open
Abstract
Skeletal muscle wasting and atrophy is one of the more severe clinical impairments resulting from the progression of Huntington's disease (HD). Mitochondrial dysfunction may play a significant role in the etiology of HD, but the specific condition of mitochondria in muscle has not been widely studied during the development of HD. To determine the role of mitochondria in skeletal muscle during the early stages of HD, we analyzed quadriceps femoris muscle from 24-, 36-, 48- and 66-month-old transgenic minipigs that expressed the N-terminal portion of mutated human huntingtin protein (TgHD) and age-matched wild-type (WT) siblings. We found altered ultrastructure of TgHD muscle tissue and mitochondria. There was also significant reduction of activity of citrate synthase and respiratory chain complexes (RCCs) I, II and IV, decreased quantity of oligomycin-sensitivity conferring protein (OSCP) and the E2 subunit of pyruvate dehydrogenase (PDHE2), and differential expression of optic atrophy 1 protein (OPA1) and dynamin-related protein 1 (DRP1) in the skeletal muscle of TgHD minipigs. Statistical analysis identified several parameters that were dependent only on HD status and could therefore be used as potential biomarkers of disease progression. In particular, the reduction of biomarker RCCII subunit SDH30 quantity suggests that similar pathogenic mechanisms underlie disease progression in TgHD minipigs and HD patients. The perturbed biochemical phenotype was detectable in TgHD minipigs prior to the development of ultrastructural changes and locomotor impairment, which become evident at the age of 48 months. Mitochondrial disturbances may contribute to energetic depression in skeletal muscle in HD, which is in concordance with the mobility problems observed in this model.This article has an associated First Person interview with the first author of the paper.
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Affiliation(s)
- Marie Rodinova
- Laboratory for Study of Mitochondrial Disorders, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12108 Prague 2, Czech Republic
| | - Jana Krizova
- Laboratory for Study of Mitochondrial Disorders, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12108 Prague 2, Czech Republic
| | - Hana Stufkova
- Laboratory for Study of Mitochondrial Disorders, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12108 Prague 2, Czech Republic
| | - Bozena Bohuslavova
- Laboratory of Cell Regeneration and Cell Plasticity, Institute of Animal Physiology and Genetics AS CR, 27721 Liběchov, Czech Republic
| | - Georgina Askeland
- Department of Medical Biochemistry, University of Oslo and Oslo University Hospital, 0372 Oslo, Norway
| | - Zaneta Dosoudilova
- Laboratory for Study of Mitochondrial Disorders, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12108 Prague 2, Czech Republic
| | - Stefan Juhas
- Laboratory of Cell Regeneration and Cell Plasticity, Institute of Animal Physiology and Genetics AS CR, 27721 Liběchov, Czech Republic
| | - Jana Juhasova
- Laboratory of Cell Regeneration and Cell Plasticity, Institute of Animal Physiology and Genetics AS CR, 27721 Liběchov, Czech Republic
| | - Zdenka Ellederova
- Laboratory of Cell Regeneration and Cell Plasticity, Institute of Animal Physiology and Genetics AS CR, 27721 Liběchov, Czech Republic
| | - Jiri Zeman
- Laboratory for Study of Mitochondrial Disorders, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12108 Prague 2, Czech Republic
| | - Lars Eide
- Department of Medical Biochemistry, University of Oslo and Oslo University Hospital, 0372 Oslo, Norway
| | - Jan Motlik
- Laboratory of Cell Regeneration and Cell Plasticity, Institute of Animal Physiology and Genetics AS CR, 27721 Liběchov, Czech Republic
| | - Hana Hansikova
- Laboratory for Study of Mitochondrial Disorders, Department of Pediatrics and Adolescent Medicine, First Faculty of Medicine, Charles University and General University Hospital in Prague, 12108 Prague 2, Czech Republic
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Abstract
Polyglutamine (polyQ) diseases are a group of hereditary neurodegenerative disorders caused by expansion of unstable polyQ repeats in their associated disease proteins. To date, the pathogenesis of each disease remains poorly understood, and there are no effective treatments. Growing evidence has indicated that, in addition to neurodegeneration, polyQ-expanded proteins can cause a wide array of abnormalities in peripheral tissues. Indeed, polyQ-expanded proteins are ubiquitously expressed throughout the body and can affect the function of both the central nervous system (CNS) and peripheral tissues. The peripheral effects of polyQ disease proteins include muscle wasting and reduced muscle strength in patients or animal models of spinal and bulbar muscular atrophy (SBMA), Huntington's disease (HD), dentatorubral-pallidoluysian atrophy (DRPLA), and spinocerebellar ataxia type 17 (SCA17). Since skeletal muscle pathology can reflect disease progression and is more accessible for treatment than neurodegeneration in the CNS, understanding how polyQ disease proteins affect skeletal muscle will help elucidate disease mechanisms and the development of new therapeutics. In this review, we focus on important findings in terms of skeletal muscle pathology in polyQ diseases and also discuss the potential mechanisms underlying the major peripheral effects of polyQ disease proteins, as well as their therapeutic implications.
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Affiliation(s)
- Shanshan Huang
- Department of Neurology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Suiqiang Zhu
- Department of Neurology, Tongji Hospital, Huazhong University of Science and Technology, Wuhan, China
| | - Xiao-Jiang Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
| | - Shihua Li
- Department of Human Genetics, Emory University School of Medicine, Atlanta, GA, USA
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16
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Toczek M, Pierzynowska K, Kutryb-Zajac B, Gaffke L, Slominska EM, Wegrzyn G, Smolenski RT. Characterization of adenine nucleotide metabolism in the cellular model of Huntington's disease. NUCLEOSIDES NUCLEOTIDES & NUCLEIC ACIDS 2018; 37:630-638. [PMID: 30587076 DOI: 10.1080/15257770.2018.1481508] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Huntington's disease (HD) is a neurodegenerative disorder that is caused by expanded CAG repeats within the exon-1 of the huntingtin (HTT) gene. It has been shown that HTT interacts with the proteins involved in the gene transcription, endocytosis and metabolism, nevertheless the biochemical pathways by which mutant HTT causes a cellular dysfunction remain unclear. Thus, this study aimed to establish the role of mutant HTT expansion in energy and nucleotide metabolism deteriorations. We examined HEK 293 T cell line transfected with plasmids expressing wild-type (control) or mutant exon 1 of the HTT gene (HD). Analysis of intracellular concentration of adenosine triphosphate (ATP) and nicotinamide adenine dinucleotide (NAD+), as well as activities of intra- and extracellular enzymes of nucleotide catabolism (such as adenine monophosphate deaminase (AMPD), adenosine deaminase (ADA), purine nucleoside phosphorylase (PNP) and ectonucleoside triphosphate diphosphohydrolase (eNTPD), ecto-5'-nucleotidase (e5NT), ecto-adenosine deaminase (eADA) were performed with high pressure liquid chromatography. Protein concentration was measured with Bradford method. We found diminished intracellular ATP concentration (22.5 ± 1.7 in HD; 29.3 ± 1.4 nmol/mg protein in control), increased ADA activity (27.9 ± 1.0 in HD; 21.1 ± 1.6 nmol/min/mg protein in control) and reduced activities of eNTPD (2.4 ± 0.5 in HD; 5.8 ± 0.7 nmol/min/mg protein in control), e5NT (0.1 ± 0.01 in HD; 0.2 ± 0.01 nmol/min/mg protein in control) and eADA (0.3 ± 0.03 in HD; 0.4 ± 0.04 nmol/min/mg protein in control) while NAD+ concentration, AMPD and PNP activities remained unchanged. This study highlights that the mutant HTT expansion resulted in depletion of cellular ATP concentration and reduced rates of extracellular nucleotide breakdown. In conclusion, such changes may contribute to the pathology of HD.
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Affiliation(s)
- Marta Toczek
- a Department of Biochemistry , Medical University of Gdansk , Gdansk , Poland
| | | | | | - Lidia Gaffke
- b Department of Molecular Biology , University of Gdansk , Gdansk , Poland
| | - Ewa M Slominska
- a Department of Biochemistry , Medical University of Gdansk , Gdansk , Poland
| | - Grzegorz Wegrzyn
- b Department of Molecular Biology , University of Gdansk , Gdansk , Poland
| | - Ryszard T Smolenski
- a Department of Biochemistry , Medical University of Gdansk , Gdansk , Poland
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17
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Krizova J, Stufkova H, Rodinova M, Macakova M, Bohuslavova B, Vidinska D, Klima J, Ellederova Z, Pavlok A, Howland DS, Zeman J, Motlik J, Hansikova H. Mitochondrial Metabolism in a Large-Animal Model of Huntington Disease: The Hunt for Biomarkers in the Spermatozoa of Presymptomatic Minipigs. NEURODEGENER DIS 2017. [PMID: 28633139 DOI: 10.1159/000475467] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022] Open
Abstract
BACKGROUND Huntington disease (HD) is a fatal neurodegenerative disorder involving reduced muscle coordination, mental and behavioral changes, and testicular degeneration. In order to further clarify the decreased fertility and penetration ability of the spermatozoa of transgenic HD minipig boars (TgHD), we applied a set of mitochondrial metabolism (MM) parameter measurements to this promising biological material, which can be collected noninvasively in longitudinal studies. OBJECTIVE We aimed to optimize methods for MM measurements in spermatozoa and to establish possible biomarkers of HD in TgHD spermatozoa expressing the N-terminal part of mutated human huntingtin. METHODS Semen samples from 12 TgHD and wild-type animals, aged 12-65 months, were obtained repeatedly during the study. Respiration was measured by polarography, MM was assessed by the detection of oxidation of radiolabeled substrates (mitochondrial energy-generating system; MEGS), and the content of the oxidative phosphorylation system subunits was detected by Western blot. Three possibly interfering factors were statistically analyzed: the effect of HD, generation and aging. RESULTS We found 5 MM parameters which were significantly diminished in TgHD spermatozoa and propose 3 specific MEGS incubations and complex I-dependent respiration as potential biomarkers of HD in TgHD spermatozoa. CONCLUSIONS Our results suggest a link between the gain of toxic function of mutated huntingtin in TgHD spermatozoa and the observed MM and/or glycolytic impairment. We determined 4 biomarkers useful for HD phenotyping and experimental therapy monitoring studies in TgHD minipigs.
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Affiliation(s)
- Jana Krizova
- Laboratory for Study of Mitochondrial Disorders, Department of Pediatrics and Adolescent Medicine, General University Hospital and First Faculty of Medicine, Charles University, Prague, Czech Republic
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18
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Polyzos AA, McMurray CT. The chicken or the egg: mitochondrial dysfunction as a cause or consequence of toxicity in Huntington's disease. Mech Ageing Dev 2017; 161:181-197. [PMID: 27634555 PMCID: PMC5543717 DOI: 10.1016/j.mad.2016.09.003] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2016] [Revised: 09/07/2016] [Accepted: 09/12/2016] [Indexed: 01/30/2023]
Abstract
Mitochondrial dysfunction and ensuing oxidative damage is typically thought to be a primary cause of Huntington's disease, Alzheimer's disease, and Parkinson disease. There is little doubt that mitochondria (MT) become defective as neurons die, yet whether MT defects are the primary cause or a detrimental consequence of toxicity remains unanswered. Oxygen consumption rate (OCR) and glycolysis provide sensitive and informative measures of the functional status MT and the cells metabolic regulation, yet these measures differ depending on the sample source; species, tissue type, age at measurement, and whether MT are measured in purified form or in a cell. The effects of these various parameters are difficult to quantify and not fully understood, but clearly have an impact on interpreting the bioenergetics of MT or their failure in disease states. A major goal of the review is to discuss issues and coalesce detailed information into a reference table to help in assessing mitochondrial dysfunction as a cause or consequence of Huntington's disease.
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Affiliation(s)
- Aris A Polyzos
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, USA.
| | - Cynthia T McMurray
- Molecular Biophysics and Integrated Bioimaging Division, Lawrence Berkeley National Laboratory, 1 Cyclotron Rd., Berkeley, CA 94720, USA.
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19
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Hering T, Braubach P, Landwehrmeyer GB, Lindenberg KS, Melzer W. Fast-to-Slow Transition of Skeletal Muscle Contractile Function and Corresponding Changes in Myosin Heavy and Light Chain Formation in the R6/2 Mouse Model of Huntington's Disease. PLoS One 2016; 11:e0166106. [PMID: 27820862 PMCID: PMC5098792 DOI: 10.1371/journal.pone.0166106] [Citation(s) in RCA: 15] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2016] [Accepted: 10/24/2016] [Indexed: 11/18/2022] Open
Abstract
Huntington´s disease (HD) is a hereditary neurodegenerative disease resulting from an expanded polyglutamine sequence (poly-Q) in the protein huntingtin (HTT). Various studies report atrophy and metabolic pathology of skeletal muscle in HD and suggest as part of the process a fast-to-slow fiber type transition that may be caused by the pathological changes in central motor control or/and by mutant HTT in the muscle tissue itself. To investigate muscle pathology in HD, we used R6/2 mice, a common animal model for a rapidly progressing variant of the disease expressing exon 1 of the mutant human gene. We investigated alterations in the extensor digitorum longus (EDL), a typical fast-twitch muscle, and the soleus (SOL), a slow-twitch muscle. We focussed on mechanographic measurements of excised muscles using single and repetitive electrical stimulation and on the expression of the various myosin isoforms (heavy and light chains) using dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE) of whole muscle and single fiber preparations. In EDL of R6/2, the functional tests showed a left shift of the force-frequency relation and decrease in specific force. Moreover, the estimated relative contribution of the fastest myosin isoform MyHC IIb decreased, whereas the contribution of the slower MyHC IIx isoform increased. An additional change occurred in the alkali MyLC forms showing a decrease in 3f and an increase in 1f level. In SOL, a shift from fast MyHC IIa to the slow isoform I was detectable in male R6/2 mice only, and there was no evidence of isoform interconversion in the MyLC pattern. These alterations point to a partial remodeling of the contractile apparatus of R6/2 mice towards a slower contractile phenotype, predominantly in fast glycolytic fibers.
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Affiliation(s)
- Tanja Hering
- Institute of Applied Physiology, Ulm University, Ulm, Germany
- Department of Neurology, Ulm University, Ulm, Germany
| | - Peter Braubach
- Institute of Applied Physiology, Ulm University, Ulm, Germany
- Institute of Pathology, Hannover Medical School, Hannover, Germany
| | | | | | - Werner Melzer
- Institute of Applied Physiology, Ulm University, Ulm, Germany
- * E-mail:
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20
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Quintanilla RA, Tapia C, Pérez MJ. Possible role of mitochondrial permeability transition pore in the pathogenesis of Huntington disease. Biochem Biophys Res Commun 2016; 483:1078-1083. [PMID: 27638306 DOI: 10.1016/j.bbrc.2016.09.054] [Citation(s) in RCA: 21] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2016] [Revised: 07/14/2016] [Accepted: 09/12/2016] [Indexed: 01/08/2023]
Abstract
Huntington disease (HD) is a devastating neurological disorder that affects the striatum and cortex of patients. HD patients develop progressive motor dysfunction and psychiatric disturbances with gradual dementia. HD is caused by a pathological expansion of CAG repeats in the huntingtin gene that codifies for a protein called huntingtin (Htt), which principal function is not completely understood. Accumulative evidence shows that this pathological expansion modifies Htt function affecting different neuronal targets, including mitochondrial function which is an important factor that contributes to HD. Interestingly, several groups have shown mitochondrial disturbances including calcium handling defects, depolarization, decrease of mitochondrial transport, ATP reduction, and increase of reactive oxygen species (ROS) in cellular and murine HD models. Systematic analysis of this evidence indicates that a mitochondrial structure, the mitochondrial permeability transition pore (mPTP), could be responsible for these changes that affect mitochondria. The mPTP plays an important role in apoptosis and neurodegeneration. It has also been reported to have some physiological functions in heart development and synaptic communication. In HD, the presence of mutant huntingtin (mHtt) activates this mechanism producing a significant compromise of mitochondrial metabolism and bioenergetics. Considering these findings this review explores the evidence that suggests the important role of mPTP in the mitochondrial impairment induced by mHtt, which leads to calcium derangement and contributes to neuronal dysfunction in HD.
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Affiliation(s)
- Rodrigo A Quintanilla
- Laboratory of Neurodegenerative Diseases, CIB, Universidad Autónoma de Chile, Chile; Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes (CIIA), Santiago, Chile.
| | - Cheril Tapia
- Laboratory of Neurodegenerative Diseases, CIB, Universidad Autónoma de Chile, Chile; Centro de Investigación y Estudio del Consumo de Alcohol en Adolescentes (CIIA), Santiago, Chile
| | - María José Pérez
- Laboratory of Neurodegenerative Diseases, CIB, Universidad Autónoma de Chile, Chile
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21
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Melkani GC. Huntington's Disease-Induced Cardiac Disorders Affect Multiple Cellular Pathways. REACTIVE OXYGEN SPECIES (APEX, N.C.) 2016; 2:325-338. [PMID: 29963642 PMCID: PMC6022757 DOI: 10.20455/ros.2016.859] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
Abstract
Huntington's disease (HD) is a rare, inherited, progressive, and fatal neurological disorder resulting from expanded polyglutamine repeats in the huntingtin protein. While HD is predominately characterized as a disease of the central nervous system, mortality surveys and epidemiological studies reveal heart disease as one of the leading causes of death in HD patients. Emerging evidence supports a link between HD and cardiovascular disease, such as cardiac amyloidosis (accumulation of aggregates in the heart). Experimental animal and clinical studies have attempted to explain the mechanisms of HD-induced cardiac pathology in the association of protein misfolding, autophagic defects, oxidative stress, mitochondrial dysfunction, and cell death. HD is increasingly understood as a complex disease with peripheral components of cardiac and skeletal muscle pathophysiology. While the discovery of these linkages and apparent pathological markers is promising, the mechanism of HD-induced cardiac pathology and the nature of its cell autonomy remain elusive. Further study of the wide-ranging cardiac function in HD patients is needed. This review highlights published literature on the pathological factors associated with HD-induced cardiac amyloidosis and other cardiovascular diseases, and addresses gaps in this expanding area of study. Through comprehensive experimental and clinical studies, potential drugs can be tested to attenuate and/or ameliorate HD-induced cardiac pathology and mortality.
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Affiliation(s)
- Girish C Melkani
- Department of Biology, Molecular Biology and Heart Institutes, San Diego State University, San Diego, CA 92182, USA
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22
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Brustovetsky N. Mutant Huntingtin and Elusive Defects in Oxidative Metabolism and Mitochondrial Calcium Handling. Mol Neurobiol 2016; 53:2944-2953. [PMID: 25941077 PMCID: PMC4635103 DOI: 10.1007/s12035-015-9188-0] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Accepted: 04/22/2015] [Indexed: 01/13/2023]
Abstract
Elongation of a polyglutamine (polyQ) stretch in huntingtin protein (Htt) is linked to Huntington's disease (HD) pathogenesis. The mutation in Htt correlates with neuronal dysfunction in the striatum and cerebral cortex and eventually leads to neuronal cell death. The exact mechanisms of the injurious effect of mutant Htt (mHtt) on neurons are not completely understood but might include aberrant gene transcription, defective autophagy, abnormal mitochondrial biogenesis, anomalous mitochondrial dynamics, and trafficking. In addition, deficiency in oxidative metabolism and defects in mitochondrial Ca(2+) handling are considered essential contributing factors to neuronal dysfunction in HD and, consequently, in HD pathogenesis. Since the discovery of the mutation in Htt, the questions whether mHtt affects oxidative metabolism and mitochondrial Ca(2+) handling and, if it does, what mechanisms could be involved were in focus of numerous investigations. However, despite significant research efforts, the detrimental effect of mHtt and the mechanisms by which mHtt might impair oxidative metabolism and mitochondrial Ca(2+) handling remain elusive. In this paper, I will briefly review studies aimed at clarifying the consequences of mHtt interaction with mitochondria and discuss experimental results supporting or arguing against the mHtt effects on oxidative metabolism and mitochondrial Ca(2+) handling.
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Affiliation(s)
- Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, 635 Barnhill Dr., Medical Science Bldg 547, Indianapolis, IN, 46202, USA.
- Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis, IN, 46202, USA.
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23
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Chandra A, Sharma A, Calingasan NY, White JM, Shurubor Y, Yang XW, Beal MF, Johri A. Enhanced mitochondrial biogenesis ameliorates disease phenotype in a full-length mouse model of Huntington's disease. Hum Mol Genet 2016; 25:2269-2282. [PMID: 27008868 DOI: 10.1093/hmg/ddw095] [Citation(s) in RCA: 28] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2015] [Accepted: 03/17/2016] [Indexed: 12/28/2022] Open
Abstract
Huntington's disease (HD) is a devastating illness and at present there is no disease modifying therapy or cure for it; and management of the disease is limited to a few treatment options for amelioration of symptoms. Recently, we showed that the administration of bezafibrate, a pan-PPAR agonist, increases the expression of PGC-1α and mitochondrial biogenesis, and improves phenotype and survival in R6/2 transgenic mouse model of HD. Since the R6/2 mice represent a 'truncated' huntingtin (Htt) mouse model of HD, we tested the efficacy of bezafibrate in a 'full-length' Htt mouse model, the BACHD mice. Bezafibrate treatment restored the impaired PPARγ, PPARδ, PGC-1α signaling pathway, enhanced mitochondrial biogenesis and improved antioxidant defense in the striatum of BACHD mice. Untreated BACHD mice show robust and progressive motor deficits, as well as late-onset and selective neuropathology in the striatum, which was markedly ameliorated in the BACHD mice treated with bezafibrate. Our data demonstrate the efficacy of bezafibrate in ameliorating both neuropathological features and disease phenotype in BACHD mice, and taken together with our previous studies with the R6/2 mice, highlight the strong therapeutic potential of bezafibrate for treatment of HD.
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Affiliation(s)
- Abhishek Chandra
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Abhijeet Sharma
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Noel Y Calingasan
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Joshua M White
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Yevgeniya Shurubor
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - X William Yang
- Center for Neurobehavioral Genetics, Semel Institute for Neuroscience and Human Behavior; Department of Psychiatry and Biobehavioral Sciences; and Brain Research Institute, David Geffen School of Medicine, University of California, Los Angeles, CA 90095, USA
| | - M Flint Beal
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
| | - Ashu Johri
- Feil Family Brain and Mind Research Institute, Weill Cornell Medical College, New York, NY 10065, USA
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24
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de Aragão BC, Rodrigues HA, Valadão PAC, Camargo W, Naves LA, Ribeiro FM, Guatimosim C. Changes in structure and function of diaphragm neuromuscular junctions from BACHD mouse model for Huntington's disease. Neurochem Int 2016; 93:64-72. [DOI: 10.1016/j.neuint.2015.12.013] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2015] [Revised: 12/17/2015] [Accepted: 12/28/2015] [Indexed: 10/22/2022]
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25
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Pellman JJ, Hamilton J, Brustovetsky T, Brustovetsky N. Ca(2+) handling in isolated brain mitochondria and cultured neurons derived from the YAC128 mouse model of Huntington's disease. J Neurochem 2015; 134:652-67. [PMID: 25963273 PMCID: PMC4516671 DOI: 10.1111/jnc.13165] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2015] [Revised: 05/04/2015] [Accepted: 05/05/2015] [Indexed: 01/10/2023]
Abstract
We investigated Ca(2+) handling in isolated brain synaptic and non-synaptic mitochondria and in cultured striatal neurons from the YAC128 mouse model of Huntington's disease. Both synaptic and non-synaptic mitochondria from 2- and 12-month-old YAC128 mice had larger Ca(2+) uptake capacity than mitochondria from YAC18 and wild-type FVB/NJ mice. Synaptic mitochondria from 12-month-old YAC128 mice had further augmented Ca(2+) capacity compared with mitochondria from 2-month-old YAC128 mice and age-matched YAC18 and FVB/NJ mice. This increase in Ca(2+) uptake capacity correlated with an increase in the amount of mutant huntingtin protein (mHtt) associated with mitochondria from 12-month-old YAC128 mice. We speculate that this may happen because of mHtt-mediated sequestration of free fatty acids thereby increasing resistance of mitochondria to Ca(2+)-induced damage. In experiments with striatal neurons from YAC128 and FVB/NJ mice, brief exposure to 25 or 100 μM glutamate produced transient elevations in cytosolic Ca(2+) followed by recovery to near resting levels. Following recovery of cytosolic Ca(2+), mitochondrial depolarization with FCCP produced comparable elevations in cytosolic Ca(2+), suggesting similar Ca(2+) release and, consequently, Ca(2+) loads in neuronal mitochondria from YAC128 and FVB/NJ mice. Together, our data argue against a detrimental effect of mHtt on Ca(2+) handling in brain mitochondria of YAC128 mice. We demonstrate that mutant huntingtin (mHtt) binds to brain synaptic and nonsynaptic mitochondria and the amount of mitochondria-bound mHtt correlates with increased mitochondrial Ca(2+) uptake capacity. We propose that this may happen due to mHtt-mediated sequestration of free fatty acids thereby increasing resistance of mitochondria to Ca(2+)-induced damage.
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Affiliation(s)
- Jessica J. Pellman
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
| | - James Hamilton
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
| | - Tatiana Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
| | - Nickolay Brustovetsky
- Department of Pharmacology and Toxicology, Indiana University School of Medicine, Indianapolis IN 46202, USA
- Stark Neuroscience Research Institute, Indiana University School of Medicine, Indianapolis IN 46202, USA
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26
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Braubach P, Orynbayev M, Andronache Z, Hering T, Landwehrmeyer GB, Lindenberg KS, Melzer W. Altered Ca(2+) signaling in skeletal muscle fibers of the R6/2 mouse, a model of Huntington's disease. ACTA ACUST UNITED AC 2015; 144:393-413. [PMID: 25348412 PMCID: PMC4210430 DOI: 10.1085/jgp.201411255] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/15/2023]
Abstract
Huntington's disease (HD) is caused by an expanded CAG trinucleotide repeat within the gene encoding the protein huntingtin. The resulting elongated glutamine (poly-Q) sequence of mutant huntingtin (mhtt) affects both central neurons and skeletal muscle. Recent reports suggest that ryanodine receptor-based Ca(2+) signaling, which is crucial for skeletal muscle excitation-contraction coupling (ECC), is changed by mhtt in HD neurons. Consequently, we searched for alterations of ECC in muscle fibers of the R6/2 mouse, a mouse model of HD. We performed fluorometric recordings of action potentials (APs) and cellular Ca(2+) transients on intact isolated toe muscle fibers (musculi interossei), and measured L-type Ca(2+) inward currents on internally dialyzed fibers under voltage-clamp conditions. Both APs and AP-triggered Ca(2+) transients showed slower kinetics in R6/2 fibers than in fibers from wild-type mice. Ca(2+) removal from the myoplasm and Ca(2+) release flux from the sarcoplasmic reticulum were characterized using a Ca(2+) binding and transport model, which indicated a significant reduction in slow Ca(2+) removal activity and Ca(2+) release flux both after APs and under voltage-clamp conditions. In addition, the voltage-clamp experiments showed a highly significant decrease in L-type Ca(2+) channel conductance. These results indicate profound changes of Ca(2+) turnover in skeletal muscle of R6/2 mice and suggest that these changes may be associated with muscle pathology in HD.
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Affiliation(s)
- Peter Braubach
- Institute of Applied Physiology and Department of Neurology, Ulm University, D-89081 Ulm, Germany
| | - Murat Orynbayev
- Institute of Applied Physiology and Department of Neurology, Ulm University, D-89081 Ulm, Germany
| | - Zoita Andronache
- Institute of Applied Physiology and Department of Neurology, Ulm University, D-89081 Ulm, Germany
| | - Tanja Hering
- Institute of Applied Physiology and Department of Neurology, Ulm University, D-89081 Ulm, Germany Institute of Applied Physiology and Department of Neurology, Ulm University, D-89081 Ulm, Germany
| | | | - Katrin S Lindenberg
- Institute of Applied Physiology and Department of Neurology, Ulm University, D-89081 Ulm, Germany
| | - Werner Melzer
- Institute of Applied Physiology and Department of Neurology, Ulm University, D-89081 Ulm, Germany
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Zielonka D, Piotrowska I, Marcinkowski JT, Mielcarek M. Skeletal muscle pathology in Huntington's disease. Front Physiol 2014; 5:380. [PMID: 25339908 PMCID: PMC4186279 DOI: 10.3389/fphys.2014.00380] [Citation(s) in RCA: 83] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2014] [Accepted: 09/13/2014] [Indexed: 12/13/2022] Open
Abstract
Huntington's disease (HD) is a hereditary neurodegenerative disorder caused by the expansion of a polyglutamine stretch within the huntingtin protein (HTT). The neurological symptoms, that involve motor, cognitive and psychiatric disturbances, are caused by neurodegeneration that is particularly widespread in the basal ganglia and cereberal cortex. HTT is ubiquitously expressed and in recent years it has become apparent that HD patients experience a wide array of peripheral organ dysfunction including severe metabolic phenotype, weight loss, HD-related cardiomyopathy and skeletal muscle wasting. Although skeletal muscles pathology became a hallmark of HD, the mechanisms underlying muscular atrophy in this disorder are unknown. Skeletal muscles account for approximately 40% of body mass and are highly adaptive to physiological and pathological conditions that may result in muscle hypertrophy (due to increased mechanical load) or atrophy (inactivity, chronic disease states). The atrophy is caused by degeneration of myofibers and their replacement by fibrotic tissue is the major pathological feature in many genetic muscle disorders. Under normal physiological conditions the muscle function is orchestrated by a network of intrinsic hypertrophic and atrophic signals linked to the functional properties of the motor units that are likely to be imbalanced in HD. In this article, we highlight the emerging field of research with particular focus on the recent studies of the skeletal muscle pathology and the identification of new disease-modifying treatments.
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Affiliation(s)
- Daniel Zielonka
- Department of Social Medicine, Poznan University of Medical Sciences Poznan, Poland
| | | | - Jerzy T Marcinkowski
- Department of Social Medicine, Poznan University of Medical Sciences Poznan, Poland
| | - Michal Mielcarek
- Department of Medical and Molecular Genetics, King's College London London, UK
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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: 313] [Impact Index Per Article: 28.5] [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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29
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Ehrnhoefer DE, Skotte NH, Ladha S, Nguyen YTN, Qiu X, Deng Y, Huynh KT, Engemann S, Nielsen SM, Becanovic K, Leavitt BR, Hasholt L, Hayden MR. p53 increases caspase-6 expression and activation in muscle tissue expressing mutant huntingtin. Hum Mol Genet 2013; 23:717-29. [PMID: 24070868 DOI: 10.1093/hmg/ddt458] [Citation(s) in RCA: 40] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
Activation of caspase-6 in the striatum of both presymptomatic and affected persons with Huntington's disease (HD) is an early event in the disease pathogenesis. However, little is known about the role of caspase-6 outside the central nervous system (CNS) and whether caspase activation might play a role in the peripheral phenotypes, such as muscle wasting observed in HD. We assessed skeletal muscle tissue from HD patients and well-characterized mouse models of HD. Cleavage of the caspase-6 specific substrate lamin A is significantly increased in skeletal muscle obtained from HD patients as well as in muscle tissues from two different HD mouse models. p53, a transcriptional activator of caspase-6, is upregulated in neuronal cells and tissues expressing mutant huntingtin. Activation of p53 leads to a dramatic increase in levels of caspase-6 mRNA, caspase-6 activity and cleavage of lamin A. Using mouse embryonic fibroblasts (MEFs) from YAC128 mice, we show that this increase in caspase-6 activity can be mitigated by pifithrin-α (pifα), an inhibitor of p53 transcriptional activity, but not through the inhibition of p53's mitochondrial pro-apoptotic function. Remarkably, the p53-mediated increase in caspase-6 expression and activation is exacerbated in cells and tissues of both neuronal and peripheral origin expressing mutant huntingtin (Htt). These findings suggest that the presence of the mutant Htt protein enhances p53 activity and lowers the apoptotic threshold, which activates caspase-6. Furthermore, these results suggest that this pathway is activated both within and outside the CNS in HD and may contribute to both loss of CNS neurons and muscle atrophy.
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Affiliation(s)
- Dagmar E Ehrnhoefer
- Centre for Molecular Medicine and Therapeutics (CMMT), Department of Medical Genetics, CFRI, University of British Columbia, 950 West 28th Avenue, Vancouver, BC V5Z 4H4, Canada
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30
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Johri A, Chandra A, Flint Beal M. PGC-1α, mitochondrial dysfunction, and Huntington's disease. Free Radic Biol Med 2013; 62:37-46. [PMID: 23602910 PMCID: PMC3722269 DOI: 10.1016/j.freeradbiomed.2013.04.016] [Citation(s) in RCA: 156] [Impact Index Per Article: 14.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/28/2012] [Revised: 04/06/2013] [Accepted: 04/12/2013] [Indexed: 12/15/2022]
Abstract
The constant high energy demand of neurons makes them rely heavily on their mitochondria. Dysfunction of mitochondrial energy metabolism leads to reduced ATP production, impaired calcium buffering, and generation of reactive oxygen species. There is strong evidence that mitochondrial dysfunction results in neurodegeneration and may contribute to the pathogenesis of Huntington's disease (HD). Studies over the past few years have implicated an impaired function of peroxisome proliferator-activated receptor (PPAR)-γ coactivator-1α (PGC-1α), a transcriptional master coregulator of mitochondrial biogenesis, metabolism, and antioxidant defenses, in causing mitochondrial dysfunction in HD. Here we have attempted to discuss in a nutshell, the key findings on the role of PGC-1α in mitochondrial dysfunction in HD and its potential as a therapeutic target to cure HD.
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Affiliation(s)
- Ashu Johri
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York-Presbyterian Hospital, New York, NY 10065, USA.
| | - Abhishek Chandra
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York-Presbyterian Hospital, New York, NY 10065, USA
| | - M Flint Beal
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York-Presbyterian Hospital, New York, NY 10065, USA
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31
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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: 26] [Impact Index Per Article: 2.4] [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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32
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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: 88] [Impact Index Per Article: 7.3] [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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33
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Calì T, Ottolini D, Brini M. Mitochondrial Ca(2+) and neurodegeneration. Cell Calcium 2012; 52:73-85. [PMID: 22608276 PMCID: PMC3396847 DOI: 10.1016/j.ceca.2012.04.015] [Citation(s) in RCA: 95] [Impact Index Per Article: 7.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/19/2012] [Revised: 04/18/2012] [Accepted: 04/20/2012] [Indexed: 12/16/2022]
Abstract
Mitochondria are essential for ensuring numerous fundamental physiological processes such as cellular energy, redox balance, modulation of Ca2+ signaling and important biosynthetic pathways. They also govern the cell fate by participating in the apoptosis pathway. The mitochondrial shape, volume, number and distribution within the cells are strictly controlled. The regulation of these parameters has an impact on mitochondrial function, especially in the central nervous system, where trafficking of mitochondria is critical to their strategic intracellular distribution, presumably according to local energy demands. Thus, the maintenance of a healthy mitochondrial population is essential to avoid the impairment of the processes they regulate: for this purpose, cells have developed mechanisms involving a complex system of quality control to remove damaged mitochondria, or to renew them. Defects of these processes impair mitochondrial function and lead to disordered cell function, i.e., to a disease condition. Given the standard role of mitochondria in all cells, it might be expected that their dysfunction would give rise to similar defects in all tissues. However, damaged mitochondrial function has pleiotropic effects in multicellular organisms, resulting in diverse pathological conditions, ranging from cardiac and brain ischemia, to skeletal muscle myopathies to neurodegenerative diseases. In this review, we will focus on the relationship between mitochondrial (and cellular) derangements and Ca2+ dysregulation in neurodegenerative diseases, emphasizing the evidence obtained in genetic models. Common patterns, that recognize the derangement of Ca2+ and energy control as a causative factor, have been identified: advances in the understanding of the molecular regulation of Ca2+ homeostasis, and on the ways in which it could become perturbed in neurological disorders, may lead to the development of therapeutic strategies that modulate neuronal Ca2+ signaling.
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Affiliation(s)
- Tito Calì
- Department of Comparative Biomedicine and Food Science, University of Padova, Padova, Italy
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34
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Costa V, Scorrano L. Shaping the role of mitochondria in the pathogenesis of Huntington's disease. EMBO J 2012; 31:1853-64. [PMID: 22446390 DOI: 10.1038/emboj.2012.65] [Citation(s) in RCA: 122] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2011] [Accepted: 02/20/2012] [Indexed: 12/28/2022] Open
Abstract
Intense research on the pathogenesis of Huntington's disease (HD), a genetic neurodegenerative disease caused by a polyglutamine expansion in the Huntingtin (Htt) protein, revealed multiple potential mechanisms, among which mitochondrial alterations had emerged as key determinants of the natural history of the disease. Pharmacological and genetic animal models of mitochondrial dysfunction in the striatum, which is mostly affected in HD corroborated a key role for these organelles in the pathogenesis of the disease. Here, we will give an account of the recent evidence indicating that the mitochondria-shaping machinery is altered in HD models and patients. Since its correction can counteract HD mitochondrial dysfunction and cellular damage, drugs impacting on mitochondrial shape are emerging as a new possibility of treatment for this devastating condition.
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Affiliation(s)
- Veronica Costa
- Department of Cell Physiology and Medicine, University of Geneva, Genève, Switzerland
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35
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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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36
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Johri A, Calingasan NY, Hennessey TM, Sharma A, Yang L, Wille E, Chandra A, Beal MF. Pharmacologic activation of mitochondrial biogenesis exerts widespread beneficial effects in a transgenic mouse model of Huntington's disease. Hum Mol Genet 2011; 21:1124-37. [PMID: 22095692 DOI: 10.1093/hmg/ddr541] [Citation(s) in RCA: 120] [Impact Index Per Article: 9.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022] Open
Abstract
There is substantial evidence that impairment of peroxisome proliferator-activated receptor (PPAR)-γ-coactivator 1α (PGC-1α) levels and activity play an important role in Huntington's disease (HD) pathogenesis. We tested whether pharmacologic treatment with the pan-PPAR agonist bezafibrate would correct a deficiency of PGC-1α and exert beneficial effects in a transgenic mouse model of HD. We found that administration of bezafibrate in the diet restored levels of PGC-1α, PPARs and downstream genes to levels which occur in wild-type mice. There were significant improvements in phenotype and survival. In the striatum, astrogliosis and neuronal atrophy were attenuated and numbers of mitochondria were increased. Bezafibrate treatment prevented conversion of type I oxidative to type II glycolytic muscle fibers and increased the numbers of muscle mitochondria. Finally, bezafibrate rescued lipid accumulation and apparent vacuolization of brown adipose tissue in the HD mice. These findings provide strong evidence that treatment with bezafibrate exerts neuroprotective effects which may be beneficial in the treatment of HD.
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Affiliation(s)
- Ashu Johri
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York-Presbyterian Hospital, New York, NY 10065, USA.
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37
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Joshi DC, Bakowska JC. SPG20 protein spartin associates with cardiolipin via its plant-related senescence domain and regulates mitochondrial Ca2+ homeostasis. PLoS One 2011; 6:e19290. [PMID: 21559443 PMCID: PMC3084803 DOI: 10.1371/journal.pone.0019290] [Citation(s) in RCA: 33] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/21/2010] [Accepted: 04/01/2011] [Indexed: 12/15/2022] Open
Abstract
Hereditary spastic paraplegias (HSPs) are a group of neurological disorders characterized clinically by spasticity of lower limbs and pathologically by degeneration of the corticospinal tract. Troyer syndrome is an autosomal recessive HSP caused by a frameshift mutation in the spartin (SPG20) gene. Previously, we established that this mutation results in a lack of expression of the truncated mutant spartin protein. Spartin is involved in many cellular processes and associates with several intracellular organelles, including mitochondria. Spartin contains a conserved plant-related senescence domain at its C-terminus. However, neither the function of this domain nor the roles of spartin in mitochondrial physiology are currently known. In this study, we determined that the plant-related senescence domain of spartin interacts with cardiolipin but not with two other major mitochondrial phospholipids, phosphatidylcholine and phosphatidylethanolamine. We also found that knockdown of spartin by small interfering RNA in a human neuroblastoma cell line resulted in depolarization of the mitochondrial membrane. In addition, depletion of spartin resulted in a significant decrease in both mitochondrial calcium uptake and mitochondrial membrane potential in cells treated with thapsigargin. Our results suggest that impairment of mitochondrial calcium uptake might contribute to the neurodegeneration of long corticospinal axons and the pathophysiology of Troyer syndrome.
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Affiliation(s)
- Dinesh C. Joshi
- Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Maywood, Illinois, United States of America
| | - Joanna C. Bakowska
- Department of Molecular Pharmacology and Therapeutics, Loyola University Chicago, Maywood, Illinois, United States of America
- * E-mail:
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38
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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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Deschepper M, Hoogendoorn B, Brooks S, Dunnett SB, Jones L. Proteomic changes in the brains of Huntington's disease mouse models reflect pathology and implicate mitochondrial changes. Brain Res Bull 2011; 88:210-22. [PMID: 21272615 DOI: 10.1016/j.brainresbull.2011.01.012] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2010] [Revised: 12/23/2010] [Accepted: 01/14/2011] [Indexed: 10/18/2022]
Abstract
Mouse models of Huntington's disease (HD) have been used extensively to recapitulate the pathological cascade of events in human HD. Mutant huntingtin interacts with many other proteins and has a well documented effect on gene expression. We were interested in whether changes in gene expression were translated into changes in the protein abundance in the brains of mouse models of HD. In two different HD knock in mouse models, the HdhQ150 and the HdhQ92, we detected changes in the abundance of proteins in mouse brain between wild-type and homozygous mutant animals. The numbers of changes detected rose with age and phenotypic severity. There were regional differences with most changes seen in the caudate and fewest in the cerebellum, reflecting the known pattern of gene expression changes in human HD and mouse models of HD and the known pathology. However, while some changes in the proteome followed changes in gene expression others did not directly reflect changes in gene expression seen in these animal models. Seven of the sixteen proteins detected have a known mitochondrial function, an enrichment of six-fold over that expected (p=0.001): these mitochondrial proteins show both increases and decreases in abundance implying that a straightforward alteration in mitochondrial number is unlikely to account for this finding.
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Affiliation(s)
- Mia Deschepper
- MRC Centre for Neuropsychiatric Genetics and Genomics, Department of Psychological Medicine, School of Medicine, Cardiff University, UK
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40
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Jin YN, Johnson GVW. The interrelationship between mitochondrial dysfunction and transcriptional dysregulation in Huntington disease. J Bioenerg Biomembr 2010; 42:199-205. [PMID: 20556492 DOI: 10.1007/s10863-010-9286-7] [Citation(s) in RCA: 55] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/07/2023]
Abstract
Huntington disease (HD) is an inherited neurodegenerative disease caused by an abnormal expansion of the CAG repeat region in the huntingtin (Htt) gene. Although the pathogenic mechanisms by which mutant Htt (mHtt) causes HD have not been fully elucidated, it is becoming increasingly apparent that mHtt can impair mitochondrial function directly, as well as indirectly by dysregulation of transcriptional processes. mHtt causes increased sensitivity to Ca(2+)-induced decreases in state 3 respiration and mitochondrial permeability transition pore (mPTP) opening concurrent with a reduction in mitochondrial Ca(2+) uptake capacity. Treatment of striatal cells expressing mHtt with thapsigargin results in a decrease in mitochondrial Ca(2+) uptake and membrane potential and an increase in reactive oxygen species (ROS) production. Transcriptional processes regulated by peroxisome proliferator-activated receptor gamma (PPAR gamma) coactivator-1 alpha (PGC-1 alpha), which are critical for mitochondrial biogenesis, have been shown to be impaired in HD. In addition, the PPAR gamma signaling pathway is impaired by mHtt and the activation of this pathway ameliorates many of the mitochondrial deficits, suggesting that PPAR gamma agonists may represent an important treatment strategy for HD.
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Affiliation(s)
- Youngnam N Jin
- Department of Anesthesiology, University of Rochester, 601 Elmwood Ave, Box 604, Rochester, NY 14642, USA
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41
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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: 1.9] [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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Zuccato C, Valenza M, Cattaneo E. Molecular Mechanisms and Potential Therapeutical Targets in Huntington's Disease. Physiol Rev 2010; 90:905-81. [DOI: 10.1152/physrev.00041.2009] [Citation(s) in RCA: 626] [Impact Index Per Article: 44.7] [Reference Citation Analysis] [Abstract] [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
| | - Marta Valenza
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milan, Italy
| | - Elena Cattaneo
- Department of Pharmacological Sciences and Centre for Stem Cell Research, Università degli Studi di Milano, Milan, Italy
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Chaturvedi RK, Calingasan NY, Yang L, Hennessey T, Johri A, Beal MF. Impairment of PGC-1alpha expression, neuropathology and hepatic steatosis in a transgenic mouse model of Huntington's disease following chronic energy deprivation. Hum Mol Genet 2010; 19:3190-205. [PMID: 20529956 DOI: 10.1093/hmg/ddq229] [Citation(s) in RCA: 113] [Impact Index Per Article: 8.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
We investigated the ability of AMP-activated protein kinase (AMPK) to activate PPARgamma coactivator-1alpha (PGC-1alpha) in the brain, liver and brown adipose tissue (BAT) of the NLS-N171-82Q transgenic mouse model of Huntington's disease (HD). In the striatum of the HD mice, the baseline levels of PGC-1alpha, NRF1, NRF2, Tfam, COX-II, PPARdelta, CREB and ERRalpha mRNA and mitochondrial DNA (mtDNA), were significantly reduced. Administration of the creatine analog beta guanidinopropionic acid (GPA) reduced ATP and PCr levels and increased AMPK mRNA in both the cerebral cortex and striatum. Treatment with GPA significantly increased expression of PGC-1alpha, NRF1, Tfam and downstream genes in the striatum and cerebral cortex of wild-type (WT) mice, but there was no effect on these genes in the HD mice. The striatum of the untreated HD mice showed microvacuolation in the neuropil, as well as gliosis and huntingtin aggregates, which were exacerbated by treatment with GPA. GPA treatment produced a significant increase in mtDNA in the cerebral cortex and striatum of WT mice, but not in HD mice. The HD mice treated with GPA had impaired activation of liver PGC-1alpha and developed hepatic steatosis with accumulation of lipids, degeneration of hepatocytes and impaired activation of gluconeogenesis. The BAT in the HD mice showed vacuolation due to accumulation of neutral lipids, and age-dependent impairment of UCP-1 activation and temperature regulation. Impaired activation of PGC-1alpha, therefore, plays an important role in the behavioral phenotype, metabolic disturbances and pathology of HD, which suggests the possibility that agents that enhance PGC-1alpha function will exert therapeutic benefits in HD patients.
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Affiliation(s)
- Rajnish K Chaturvedi
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York, NY 10065, USA. /
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Gellerich FN, Gizatullina Z, Trumbeckaite S, Nguyen HP, Pallas T, Arandarcikaite O, Vielhaber S, Seppet E, Striggow F. The regulation of OXPHOS by extramitochondrial calcium. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2010; 1797:1018-27. [PMID: 20144582 DOI: 10.1016/j.bbabio.2010.02.005] [Citation(s) in RCA: 82] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/11/2009] [Revised: 02/01/2010] [Accepted: 02/02/2010] [Indexed: 11/29/2022]
Abstract
Despite extensive research, the regulation of mitochondrial function is still not understood completely. Ample evidence shows that cytosolic Ca2+ has a strategic task in co-ordinating the cellular work load and the regeneration of ATP by mitochondria. Currently, the paradigmatic view is that Cacyt2+ taken up by the Ca2+ uniporter activates the matrix enzymes pyruvate dehydrogenase, alpha-ketoglutarate dehydrogenase and isocitrate dehydrogenase. However, we have recently found that Ca2+ regulates the glutamate-dependent state 3 respiration by the supply of glutamate to mitochondria via aralar, a mitochondrial glutamate/aspartate carrier. Since this activation is not affected by ruthenium red, glutamate transport into mitochondria is controlled exclusively by extramitochondrial Ca2+. Therefore, this discovery shows that besides intramitochondrial also extramitochondrial Ca2+ regulates oxidative phosphorylation. This new mechanism acts as a mitochondrial "gas pedal", supplying the OXPHOS with substrate on demand. These results are in line with recent findings of Satrustegui and Palmieri showing that aralar as part of the malate-aspartate shuttle is involved in the Ca2+-dependent transport of reducing hydrogen equivalents (from NADH) into mitochondria. This review summarises results and evidence as well as hypothetical interpretations of data supporting the view that at the surface of mitochondria different regulatory Ca2+-binding sites exist and can contribute to cellular energy homeostasis. Moreover, on the basis of our own data, we propose that these surface Ca2+-binding sites may act as targets for neurotoxic proteins such as mutated huntingtin and others. The binding of these proteins to Ca2+-binding sites can impair the regulation by Ca2+, causing energetic depression and neurodegeneration.
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Affiliation(s)
- Frank N Gellerich
- KeyNeurotek Pharmaceuticals AG, ZENIT Technology Park, Leipziger Str. 44, D-39120 Magdeburg, Germany.
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45
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Abnormal morphology of peripheral cell tissues from patients with Huntington disease. J Neural Transm (Vienna) 2009; 117:77-83. [DOI: 10.1007/s00702-009-0328-4] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/25/2009] [Accepted: 09/20/2009] [Indexed: 12/12/2022]
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46
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van der Burg JMM, Björkqvist M, Brundin P. Beyond the brain: widespread pathology in Huntington's disease. Lancet Neurol 2009; 8:765-74. [DOI: 10.1016/s1474-4422(09)70178-4] [Citation(s) in RCA: 199] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/20/2022]
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47
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Quintanilla RA, Johnson GVW. Role of mitochondrial dysfunction in the pathogenesis of Huntington's disease. Brain Res Bull 2009; 80:242-7. [PMID: 19622387 DOI: 10.1016/j.brainresbull.2009.07.010] [Citation(s) in RCA: 112] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [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)
- Rodrigo A Quintanilla
- Department of Anesthesiology, University of Rochester, Rochester, NY 14642-0002, USA
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Chaturvedi RK, Adhihetty P, Shukla S, Hennessy T, Calingasan N, Yang L, Starkov A, Kiaei M, Cannella M, Sassone J, Ciammola A, Squitieri F, Beal MF. Impaired PGC-1alpha function in muscle in Huntington's disease. Hum Mol Genet 2009; 18:3048-65. [PMID: 19460884 DOI: 10.1093/hmg/ddp243] [Citation(s) in RCA: 184] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigated the role of PPAR gamma coactivator 1alpha (PGC-1alpha) in muscle dysfunction in Huntington's disease (HD). We observed reduced PGC-1alpha and target genes expression in muscle of HD transgenic mice. We produced chronic energy deprivation in HD mice by administering the catabolic stressor beta-guanidinopropionic acid (GPA), a creatine analogue that reduces ATP levels, activates AMP-activated protein kinase (AMPK), which in turn activates PGC-1alpha. Treatment with GPA resulted in increased expression of AMPK, PGC-1alpha target genes, genes for oxidative phosphorylation, electron transport chain and mitochondrial biogenesis, increased oxidative muscle fibers, numbers of mitochondria and motor performance in wild-type, but not in HD mice. In muscle biopsies from HD patients, there was decreased PGC-1alpha, PGC-1beta and oxidative fibers. Oxygen consumption, PGC-1alpha, NRF1 and response to GPA were significantly reduced in myoblasts from HD patients. Knockdown of mutant huntingtin resulted in increased PGC-1alpha expression in HD myoblast. Lastly, adenoviral-mediated delivery of PGC-1alpha resulted increased expression of PGC-1alpha and markers for oxidative muscle fibers and reversal of blunted response for GPA in HD mice. These findings show that impaired function of PGC-1alpha plays a critical role in muscle dysfunction in HD, and that treatment with agents to enhance PGC-1alpha function could exert therapeutic benefits. Furthermore, muscle may provide a readily accessible tissue in which to monitor therapeutic interventions.
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Affiliation(s)
- Rajnish K Chaturvedi
- Department of Neurology and Neuroscience, Weill Medical College of Cornell University, New York-Presbyterian Hospital, New York, NY 10065, USA.
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49
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Seppet E, Gruno M, Peetsalu A, Gizatullina Z, Nguyen HP, Vielhaber S, Wussling MH, Trumbeckaite S, Arandarcikaite O, Jerzembeck D, Sonnabend M, Jegorov K, Zierz S, Striggow F, Gellerich FN. Mitochondria and energetic depression in cell pathophysiology. Int J Mol Sci 2009; 10:2252-2303. [PMID: 19564950 PMCID: PMC2695278 DOI: 10.3390/ijms10052252] [Citation(s) in RCA: 62] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2009] [Revised: 04/25/2009] [Accepted: 05/14/2009] [Indexed: 12/21/2022] Open
Abstract
Mitochondrial dysfunction is a hallmark of almost all diseases. Acquired or inherited mutations of the mitochondrial genome DNA may give rise to mitochondrial diseases. Another class of disorders, in which mitochondrial impairments are initiated by extramitochondrial factors, includes neurodegenerative diseases and syndromes resulting from typical pathological processes, such as hypoxia/ischemia, inflammation, intoxications, and carcinogenesis. Both classes of diseases lead to cellular energetic depression (CED), which is characterized by decreased cytosolic phosphorylation potential that suppresses the cell's ability to do work and control the intracellular Ca(2+) homeostasis and its redox state. If progressing, CED leads to cell death, whose type is linked to the functional status of the mitochondria. In the case of limited deterioration, when some amounts of ATP can still be generated due to oxidative phosphorylation (OXPHOS), mitochondria launch the apoptotic cell death program by release of cytochrome c. Following pronounced CED, cytoplasmic ATP levels fall below the thresholds required for processing the ATP-dependent apoptotic cascade and the cell dies from necrosis. Both types of death can be grouped together as a mitochondrial cell death (MCD). However, there exist multiple adaptive reactions aimed at protecting cells against CED. In this context, a metabolic shift characterized by suppression of OXPHOS combined with activation of aerobic glycolysis as the main pathway for ATP synthesis (Warburg effect) is of central importance. Whereas this type of adaptation is sufficiently effective to avoid CED and to control the cellular redox state, thereby ensuring the cell survival, it also favors the avoidance of apoptotic cell death. This scenario may underlie uncontrolled cellular proliferation and growth, eventually resulting in carcinogenesis.
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Affiliation(s)
- Enn Seppet
- Department of Pathophysiology, University of Tartu, Tartu, Estonia; E-Mail:
(M.G.)
| | - Marju Gruno
- Department of Pathophysiology, University of Tartu, Tartu, Estonia; E-Mail:
(M.G.)
| | - Ants Peetsalu
- Department of Surgery, University of Tartu, Tartu, Estonia; E-Mail:
(A.P.)
| | - Zemfira Gizatullina
- KeyNeurotek AG, ZENIT-Technology Park Magdeburg, Magdeburg, Germany; E-Mails:
(Z.G.);
(D.J.);
(M.S.);
(K.J.);
(F.S.);
(F.N.G.)
| | - Huu Phuc Nguyen
- Department of Medical Genetics, University of Tübingen, Tübingen, Germany; E-Mail:
(H.P.N.)
| | - Stefan Vielhaber
- Department of Neurology, Otto von Guericke University, Magdeburg, Germany; E-Mail:
(S.V.)
| | - Manfred H.P. Wussling
- Bernstein Institute for Physiology, Martin-Luther-University Halle-Wittenberg, Germany; E-Mail:
(M.H.P.W.)
| | - Sonata Trumbeckaite
- Institute for Biomedical Research, Kaunas University of Medicine, Kaunas, Lithuania; E-Mails:
(S.T.);
(O.A.)
| | - Odeta Arandarcikaite
- Institute for Biomedical Research, Kaunas University of Medicine, Kaunas, Lithuania; E-Mails:
(S.T.);
(O.A.)
| | - Doreen Jerzembeck
- KeyNeurotek AG, ZENIT-Technology Park Magdeburg, Magdeburg, Germany; E-Mails:
(Z.G.);
(D.J.);
(M.S.);
(K.J.);
(F.S.);
(F.N.G.)
| | - Maria Sonnabend
- KeyNeurotek AG, ZENIT-Technology Park Magdeburg, Magdeburg, Germany; E-Mails:
(Z.G.);
(D.J.);
(M.S.);
(K.J.);
(F.S.);
(F.N.G.)
| | - Katharina Jegorov
- KeyNeurotek AG, ZENIT-Technology Park Magdeburg, Magdeburg, Germany; E-Mails:
(Z.G.);
(D.J.);
(M.S.);
(K.J.);
(F.S.);
(F.N.G.)
| | - Stephan Zierz
- Department of Neurology, Martin-Luther-University Halle-Wittenberg, Germany; E-Mail:
(S.Z.)
| | - Frank Striggow
- KeyNeurotek AG, ZENIT-Technology Park Magdeburg, Magdeburg, Germany; E-Mails:
(Z.G.);
(D.J.);
(M.S.);
(K.J.);
(F.S.);
(F.N.G.)
| | - Frank N. Gellerich
- KeyNeurotek AG, ZENIT-Technology Park Magdeburg, Magdeburg, Germany; E-Mails:
(Z.G.);
(D.J.);
(M.S.);
(K.J.);
(F.S.);
(F.N.G.)
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Sassone J, Colciago C, Cislaghi G, Silani V, Ciammola A. Huntington's disease: the current state of research with peripheral tissues. Exp Neurol 2009; 219:385-97. [PMID: 19460373 DOI: 10.1016/j.expneurol.2009.05.012] [Citation(s) in RCA: 124] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2008] [Revised: 04/30/2009] [Accepted: 05/09/2009] [Indexed: 01/23/2023]
Abstract
Huntington's disease (HD) is a genetically dominant condition caused by expanded CAG repeats. These repeats code for a glutamine tract in the HD gene product huntingtin (htt), which is a protein expressed in almost all tissues. Although most HD symptoms reflect preferential neuronal death in specific brain regions, even before the HD gene was identified numerous reports had described additional abnormalities in the peripheral tissues of HD patients, including weight loss, altered glucose homeostasis, and sub-cellular abnormalities in fibroblasts, lymphocytes and erythrocytes. Several years have elapsed since the HD mutation was discovered, and analyses of peripheral tissues from HD patients have helped to understand the molecular pathogenesis of the disease and revealed that the molecular mechanisms through which mutated htt leads to cell dysfunction are widely shared between central nervous system (CNS) and peripheral tissues. These studies show that in peripheral tissues, mutated htt causes accumulation of intracellular protein aggregates, impairment of energetic metabolism, transcriptional deregulation and hyperactivation of programmed cell-death mechanisms. Here, we review the current knowledge of peripheral tissue alterations in HD patients and in animal models of HD and focus on how this information can be used to identify potential therapeutic possibilities and biomarkers for disease progression.
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Affiliation(s)
- Jenny Sassone
- Department of Neurology and Laboratory of Neuroscience, Dino Ferrari Center, IRCCS Istituto Auxologico Italiano, University of Milan Medical School, via Spagnoletto 3, 20149, Milan, Italy
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