1
|
Oxygen-Glucose Deprivation Decreases the Motility and Length of Axonal Mitochondria in Cultured Dorsal Root Ganglion Cells of Rats. Cell Mol Neurobiol 2023; 43:1267-1280. [PMID: 35771293 DOI: 10.1007/s10571-022-01247-y] [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: 04/08/2022] [Accepted: 06/20/2022] [Indexed: 11/03/2022]
Abstract
Controlling axonal mitochondria is important for maintaining normal function of the neural network. Oxygen-glucose deprivation (OGD), a model used for mimicking ischemia, eventually induces neuronal cell death similar to axonal degeneration. Axonal mitochondria are disrupted during OGD-induced neural degeneration; however, the mechanism underlying mitochondrial dysfunction has not been completely understood. We focused on the dynamics of mitochondria in axons exposed to OGD; we observed that the number of motile mitochondria significantly reduced in 1 h following OGD exposure. In our observation, the decreased length of stationary mitochondria was affected by the following factors: first, the halt of motile mitochondria; second, the fission of longer stationary mitochondria; and third, a transformation from tubular to spherical shape in OGD-exposed axons. Motile mitochondria reduction preceded stationary mitochondria fragmentation in OGD exposure; these conditions induced the decrease of stationary mitochondria in three different ways. Our results suggest that mitochondrial morphological changes precede the axonal degeneration while ischemia-induced neurodegeneration.
Collapse
|
2
|
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.
Collapse
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.
| |
Collapse
|
3
|
Kedra J, Lin S, Pacheco A, Gallo G, Smith GM. Axotomy Induces Drp1-Dependent Fragmentation of Axonal Mitochondria. Front Mol Neurosci 2021; 14:668670. [PMID: 34149354 PMCID: PMC8209475 DOI: 10.3389/fnmol.2021.668670] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/16/2021] [Accepted: 05/07/2021] [Indexed: 02/02/2023] Open
Abstract
It is well established that CNS axons fail to regenerate, undergo retrograde dieback, and form dystrophic growth cones due to both intrinsic and extrinsic factors. We sought to investigate the role of axonal mitochondria in the axonal response to injury. A viral vector (AAV) containing a mitochondrially targeted fluorescent protein (mitoDsRed) as well as fluorescently tagged LC3 (GFP-LC3), an autophagosomal marker, was injected into the primary motor cortex, to label the corticospinal tract (CST), of adult rats. The axons of the CST were then injured by dorsal column lesion at C4-C5. We found that mitochondria in injured CST axons near the injury site are fragmented and fragmentation of mitochondria persists for 2 weeks before returning to pre-injury lengths. Fragmented mitochondria have consistently been shown to be dysfunctional and detrimental to cellular health. Inhibition of Drp1, the GTPase responsible for mitochondrial fission, using a specific pharmacological inhibitor (mDivi-1) blocked fragmentation. Additionally, it was determined that there is increased mitophagy in CST axons following Spinal cord injury (SCI) based on increased colocalization of mitochondria and LC3. In vitro models revealed that mitochondrial divalent ion uptake is necessary for injury-induced mitochondrial fission, as inhibiting the mitochondrial calcium uniporter (MCU) using RU360 prevented injury-induced fission. This phenomenon was also observed in vivo. These studies indicate that following the injury, both in vivo and in vitro, axonal mitochondria undergo increased fission, which may contribute to the lack of regeneration seen in CNS neurons.
Collapse
Affiliation(s)
- Joseph Kedra
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Shen Lin
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Almudena Pacheco
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - Gianluca Gallo
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States.,Department of Anatomy and Cell Biology, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| | - George M Smith
- Shriners Hospitals Pediatric Research Center, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States.,Department of Neuroscience, Lewis Katz School of Medicine, Temple University, Philadelphia, PA, United States
| |
Collapse
|
4
|
Gatto EM, Rojas NG, Persi G, Etcheverry JL, Cesarini ME, Perandones C. Huntington disease: Advances in the understanding of its mechanisms. Clin Park Relat Disord 2020; 3:100056. [PMID: 34316639 PMCID: PMC8298812 DOI: 10.1016/j.prdoa.2020.100056] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/20/2019] [Revised: 02/01/2020] [Accepted: 04/28/2020] [Indexed: 01/30/2023] Open
Abstract
Huntington disease (HD) is a devastating monogenic autosomal dominant disorder. HD is caused by a CAG expansion in exon 1 of the gene coding for huntingtin, placed in the short arm of chromosome 4. Despite its well-defined genetic origin, the molecular and cellular mechanisms underlying the disease are unclear and complex. Here, we review some of the currently known functions of the wild-type huntingtin protein and discuss the deleterious effects that arise from the expansion of the CAG repeats, which are translated into an abnormally long polyglutamine tract. Also, we present a modern view on the molecular biology of HD as a representative of the group of polyglutamine diseases, with an emphasis on conformational changes of mutant huntingtin, disturbances in its cellular processing, and proteolytic stress in degenerating neurons. The main pathogenetic mechanisms of neurodegeneration in HD are discussed in detail, such as autophagy, impaired mitochondrial biogenesis, lysosomal dysfunction, organelle and protein transport, inflammation, oxidative stress, and transcription factor modulation. However, other unraveling mechanisms are still unknown. This practical and brief review summarizes some of the currently known functions of the wild-type huntingtin protein and the recent findings related to the mechanisms involved in HD pathogenesis.
Collapse
Affiliation(s)
- Emilia M Gatto
- Institute of Neuroscience Buenos Aires (INEBA), Argentina.,Sanatorio de la Trinidad Mitre, Argentina
| | | | - Gabriel Persi
- Institute of Neuroscience Buenos Aires (INEBA), Argentina.,Sanatorio de la Trinidad Mitre, Argentina
| | | | | | - Claudia Perandones
- National Administration of Laboratories and Institutes of Health, ANLIS, Dr. Carlos G. Malbrán, Argentina
| |
Collapse
|
5
|
Role of PGC-1α in Mitochondrial Quality Control in Neurodegenerative Diseases. Neurochem Res 2019; 44:2031-2043. [PMID: 31410709 DOI: 10.1007/s11064-019-02858-6] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2019] [Revised: 07/17/2019] [Accepted: 08/08/2019] [Indexed: 12/13/2022]
Abstract
As one of the major cell organelles responsible for ATP production, it is important that neurons maintain mitochondria with structural and functional integrity; this is especially true for neurons with high metabolic requirements. When mitochondrial damage occurs, mitochondria are able to maintain a steady state of functioning through molecular and organellar quality control, thus ensuring neuronal function. And when mitochondrial quality control (MQC) fails, mitochondria mediate apoptosis. An apparently key molecule in MQC is the transcriptional coactivator peroxisome proliferator activated receptor γ coactivator-1α (PGC-1α). Recent findings have demonstrated that upregulation of PGC-1α expression in neurons can modulate MQC to prevent mitochondrial dysfunction in certain in vivo and in vitro aging or neurodegenerative encephalopathy models, such as Huntington's disease, Alzheimer's disease, and Parkinson's disease. Because mitochondrial function and quality control disorders are the basis of pathogenesis in almost all neurodegenerative diseases (NDDs), the role of PGC-1α may make it a viable entry point for the treatment of such diseases. This review focuses on multi-level MQC in neurons, as well as the regulation of MQC by PGC-1α in these major NDDs.
Collapse
|
6
|
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.
Collapse
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
| |
Collapse
|
7
|
Mitochondria-Targeted Peptide SS31 Attenuates Renal Tubulointerstitial Injury via Inhibiting Mitochondrial Fission in Diabetic Mice. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2019; 2019:2346580. [PMID: 31281569 PMCID: PMC6589270 DOI: 10.1155/2019/2346580] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 01/21/2019] [Revised: 04/10/2019] [Accepted: 04/23/2019] [Indexed: 02/06/2023]
Abstract
Objective Renal tubular injury is an early characteristic of diabetic nephropathy (DN) that is related to mitochondrial dysfunction. In this study, we explore the effects and mechanisms of mitochondria-targeted peptide SS31 on renal tubulointerstitial injury in DN. Method 40 C57BL/6 mice were randomly divided into control group, STZ group, STZ+SS31 group, and STZ+normal saline group. SS31 was intraperitoneally injected to the mice every other day for 24 weeks. Renal lesions and the expression of Drp1, Mfn1, Bcl-2, Bax, Caspase1, IL-1β, and FN were detected. In in vitro studies, HK-2 cells were incubated with different concentrations of D-glucose (5, 30 mM) or combined with SS31 and Drp1 inhibitor Midivi1. Mitochondrial ROS, membrane potential, and morphology have been detected to evaluate the mitochondrial function. Results Compared with diabetic mice, the levels of serum creatinine and microalbuminuria were significantly decreased in the SS31 group. Renal tubulointerstitial fibrosis, oxidative stress, and apoptosis were observed in diabetic mice, while the pathological changes were reduced in the SS31-treatment group. SS31 could decrease the expression of Drp1, Bax, Caspase1, IL-1β, and FN in the renal tissue of diabetic mice, while increasing the expression of Mfn1. Additionally, mitochondria exhibit focal enlargement and crista swelling in renal tubular cells of diabetic mice, while SS31 treatment could partially block these changes. An in vitro study showed that pretreatment with SS31 or Drp1 inhibitor Mdivi1 could restore the level of mitochondrial ROS, the membrane potential levels, and the expressions of Drp1, Bax, Caspase1, IL-1β, and FN in HK-2 cells under high-glucose conditions. Conclusion SS31 protected renal tubulointerstitial injury in diabetic mice through a decrease in mitochondrial fragmentation via suppressing the expression of Drp1 and increasing the expression of Mfn1.
Collapse
|
8
|
Huang NK, Lin CC, Lin YL, Huang CL, Chiou CT, Lee YC, Lee SY, Huang HT, Yang YC. Morphological control of mitochondria as the novel mechanism of Gastrodia elata in attenuating mutant huntingtin-induced protein aggregations. PHYTOMEDICINE : INTERNATIONAL JOURNAL OF PHYTOTHERAPY AND PHYTOPHARMACOLOGY 2019; 59:152756. [PMID: 31004885 DOI: 10.1016/j.phymed.2018.11.016] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2018] [Accepted: 11/13/2018] [Indexed: 06/09/2023]
Abstract
BACKGROUND According to Compendium of Materia Medica, Gastrodia elata (GE) Blume as a top grade and frequently prescribed herbal medicine has been used in treating dizziness, headaches, and epilepsy, indicating a neuroprotective effect. Because GE is capable of suppressing a hyperactive liver and thus calming endogenous wind, and because Huntington's disease (HD) can be classified as a phenomenon of disturbed liver wind, it is suggested that GE might be beneficial in treating HD. However, although current studies support GE for the prevention of diverse neurodegenerations such as HD, its detailed mechanisms remain elusive. PURPOSE To investigate the molecular mechanism of GE in preventing HD by focusing on mitochondrial morphology, which is highly associated with HD etiology and thus proposed as a therapeutic target of neurodegenerations. STUDY DESIGN/METHODS The overexpression of the mutant huntingtin (mHTT) gene in rat pheochromocytoma (PC12) cells was used as an in vitro cell model of HD. A filter retardation assay was applied to measure protein aggregations during HTT expression. Cotransfection with mitochondrial fusion and fission genes was used to test their relationships with HTT aggregates by monitoring with a confocal laser scanning microscope and filter retardation assay. Western blot analysis was used to estimate protein expression under different drug treatments or cotransfections with other related genes. RESULTS The overexpression of mutant but not normal HTT genes significantly resulted in protein aggregations in PC12 cells. GE dose-dependently attenuated mHTT-induced protein aggregations and free radical formations. GE significantly reversed mHTT-induced mitochondrial fragmentation and dysregulation of mitochondrial fusion and fission molecules. The overexpression of mitochondrial fusion genes attenuated mHTT-induced protein aggregations. Further, Mdivi-1, a DRP1 fission molecule inhibitor, significantly reversed mHTT-induced protein aggregations and mitochondrial fragmentation. CONCLUSION GE attenuated mHTT aggregations through the control of mitochondrial fusion and the fission pathway.
Collapse
Affiliation(s)
- Nai-Kuei Huang
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan, ROC; Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan, ROC
| | - Chung-Chih Lin
- Brain Research Center, National Yang-Ming University, Taipei, Taiwan, ROC; Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC; Biophotonics Interdisciplinary Research Center, National Yang-Ming University, Taipei, Taiwan, ROC
| | - Yun-Lian Lin
- School of Chinese Pharmaceutical Sciences and Chinese Medicine Resources, College of Biopharmaceutical and Food Sciences, China Medical University, Taichung, Taiwan, ROC
| | - Chuen-Lin Huang
- Medical Research Center, Cardinal Tien Hospital, Hsintien, New Taipei City, Taiwan, ROC; Graduate Institute of Physiology & Department of Physiology and Biophysics, National Defense Medical Center, Taipei, Taiwan, ROC
| | - Chun-Tang Chiou
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan, ROC
| | - Yi-Chao Lee
- Program for Neural Regenerative Medicine, College of Medical Science and Technology, Taipei Medical University, Taipei, Taiwan, ROC
| | - Shu-Yi Lee
- Department of Life Sciences and Institute of Genome Sciences, National Yang-Ming University, Taipei, Taiwan, ROC
| | - Hung-Tse Huang
- National Research Institute of Chinese Medicine, Ministry of Health and Welfare, Taipei, Taiwan, ROC
| | - Ying-Chen Yang
- Department of Biotechnology and Animal Science, National Ilan University, Ilan, Taiwan, ROC.
| |
Collapse
|
9
|
Soares TR, Reis SD, Pinho BR, Duchen MR, Oliveira JMA. Targeting the proteostasis network in Huntington's disease. Ageing Res Rev 2019; 49:92-103. [PMID: 30502498 PMCID: PMC6320389 DOI: 10.1016/j.arr.2018.11.006] [Citation(s) in RCA: 49] [Impact Index Per Article: 9.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/31/2018] [Revised: 11/19/2018] [Accepted: 11/26/2018] [Indexed: 12/31/2022]
Abstract
Huntington's disease (HD) is an autosomal dominant neurodegenerative disorder caused by a polyglutamine expansion mutation in the huntingtin protein. Expansions above 40 polyglutamine repeats are invariably fatal, following a symptomatic period characterised by choreiform movements, behavioural abnormalities, and cognitive decline. While mutant huntingtin (mHtt) is widely expressed from early life, most patients with HD present in mid-adulthood, highlighting the role of ageing in disease pathogenesis. mHtt undergoes proteolytic cleavage, misfolding, accumulation, and aggregation into inclusion bodies. The emerging model of HD pathogenesis proposes that the chronic production of misfolded mHtt overwhelms the chaperone machinery, diverting other misfolded clients to the proteasome and the autophagy pathways, ultimately leading to a global collapse of the proteostasis network. Multiple converging hypotheses also implicate ageing and its impact in the dysfunction of organelles as additional contributing factors to the collapse of proteostasis in HD. In particular, mitochondrial function is required to sustain the activity of ATP-dependent chaperones and proteolytic machinery. Recent studies elucidating mitochondria-endoplasmic reticulum interactions and uncovering a dedicated proteostasis machinery in mitochondria, suggest that mitochondria play a more active role in the maintenance of cellular proteostasis than previously thought. The enhancement of cytosolic proteostasis pathways shows promise for HD treatment, protecting cells from the detrimental effects of mHtt accumulation. In this review, we consider how mHtt and its post translational modifications interfere with protein quality control pathways, and how the pharmacological and genetic modulation of components of the proteostasis network impact disease phenotypes in cellular and in vivo HD models.
Collapse
Affiliation(s)
- Tânia R Soares
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal; Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK
| | - Sara D Reis
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Brígida R Pinho
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal
| | - Michael R Duchen
- Department of Cell and Developmental Biology, University College London, London, WC1E 6BT, UK; Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, WC1E 6BT, London, UK
| | - Jorge M A Oliveira
- REQUIMTE/LAQV, Department of Drug Sciences, Pharmacology Lab, Faculty of Pharmacy, University of Porto, 4050-313, Porto, Portugal; Consortium for Mitochondrial Research (CfMR), University College London, Gower Street, WC1E 6BT, London, UK.
| |
Collapse
|
10
|
Daghistani HM, Rajab BS, Kitmitto A. Three-dimensional electron microscopy techniques for unravelling mitochondrial dysfunction in heart failure and identification of new pharmacological targets. Br J Pharmacol 2018; 176:4340-4359. [PMID: 30225980 PMCID: PMC6887664 DOI: 10.1111/bph.14499] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2018] [Revised: 07/30/2018] [Accepted: 08/18/2018] [Indexed: 12/23/2022] Open
Abstract
A hallmark of heart failure is mitochondrial dysfunction leading to a bioenergetics imbalance in the myocardium. Consequently, there is much interest in targeting mitochondrial abnormalities to attenuate the pathogenesis of heart failure. This review discusses (i) how electron microscopy (EM) techniques have been fundamental for the current understanding of mitochondrial structure–function, (ii) the paradigm shift in resolutions now achievable by 3‐D EM techniques due to the introduction of direct detection devices and phase plate technology, and (iii) the application of EM for unravelling mitochondrial pathological remodelling in heart failure. We further consider the tremendous potential of multi‐scale EM techniques for the development of therapeutics, structure‐based ligand design and for delineating how a drug elicits nanostructural effects at the molecular, organelle and cellular levels. In conclusion, 3‐D EM techniques have entered a new era of structural biology and are poised to play a pivotal role in discovering new therapies targeting mitochondria for treating heart failure. Linked Articles This article is part of a themed section on Mitochondrial Pharmacology: Featured Mechanisms and Approaches for Therapy Translation. To view the other articles in this section visit http://onlinelibrary.wiley.com/doi/10.1111/bph.v176.22/issuetoc
Collapse
Affiliation(s)
- Hussam M Daghistani
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Bodour S Rajab
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| | - Ashraf Kitmitto
- Division of Cardiovascular Sciences, School of Medical Sciences, Faculty of Biology, Medicine and Health, The University of Manchester, Manchester Academic Health Science Centre, Manchester, UK
| |
Collapse
|
11
|
Abstract
This review systematically examines the evidence for shifts in flux through energy generating biochemical pathways in Huntington’s disease (HD) brains from humans and model systems. Compromise of the electron transport chain (ETC) appears not to be the primary or earliest metabolic change in HD pathogenesis. Rather, compromise of glucose uptake facilitates glucose flux through glycolysis and may possibly decrease flux through the pentose phosphate pathway (PPP), limiting subsequent NADPH and GSH production needed for antioxidant protection. As a result, oxidative damage to key glycolytic and tricarboxylic acid (TCA) cycle enzymes further restricts energy production so that while basal needs may be met through oxidative phosphorylation, those of excessive stimulation cannot. Energy production may also be compromised by deficits in mitochondrial biogenesis, dynamics or trafficking. Restrictions on energy production may be compensated for by glutamate oxidation and/or stimulation of fatty acid oxidation. Transcriptional dysregulation generated by mutant huntingtin also contributes to energetic disruption at specific enzymatic steps. Many of the alterations in metabolic substrates and enzymes may derive from normal regulatory feedback mechanisms and appear oscillatory. Fine temporal sequencing of the shifts in metabolic flux and transcriptional and expression changes associated with mutant huntingtin expression remain largely unexplored and may be model dependent. Differences in disease progression among HD model systems at the time of experimentation and their varying states of metabolic compensation may explain conflicting reports in the literature. Progressive shifts in metabolic flux represent homeostatic compensatory mechanisms that maintain the model organism through presymptomatic and symptomatic stages.
Collapse
Affiliation(s)
- Janet M Dubinsky
- Department of Neuroscience, University of Minnesota, Minneapolis, MN, USA
| |
Collapse
|
12
|
Saavedra A, García-Díaz Barriga G, Pérez-Navarro E, Alberch J. Huntington's disease: novel therapeutic perspectives hanging in the balance. Expert Opin Ther Targets 2018; 22:385-399. [PMID: 29671352 DOI: 10.1080/14728222.2018.1465930] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023]
Abstract
INTRODUCTION Huntington's disease (HD), an autosomal dominant neurodegenerative disorder caused by an expansion of CAG repeats in the huntingtin gene, has long been characterized by the presence of motor symptoms due to the loss of striatal projection neurons. Cognitive dysfunction and neuropsychiatric symptoms are also present and they occur in the absence of cell death in most mouse models, pointing to neuronal dysfunction and abnormal synaptic plasticity as causative mechanisms. Areas covered: Here, we focus on those common mechanisms altered by the presence of mutant huntingtin affecting corticostriatal and hippocampal function as therapeutic targets that could prove beneficial to ameliorate both cognitive and motor function in HD. Specifically, we discuss the importance of reestablishing the balance in (1) synaptic/extrasynaptic N-methyl-D-aspartate receptor signaling, (2) mitochondrial dynamics/trafficking, (3) TrkB/p75NTR signaling, and (4) transcriptional activity. Expert opinion: Mutant huntingtin has a broad impact on multiple cellular processes, which makes it very challenging to design a curative therapeutic strategy. As we point out here, novel therapeutic interventions should look for multi-purpose drugs targeting common and early affected processes leading to corticostriatal and hippocampal dysfunction that additionally operate in a feedforward vicious cycle downstream the activation of extrasynaptic N-methyl-D-aspartate receptor.
Collapse
Affiliation(s)
- Ana Saavedra
- a Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències , Universitat de Barcelona , Barcelona , Spain.,b Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) , Barcelona , Spain.,c Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Spain
| | - Gerardo García-Díaz Barriga
- a Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències , Universitat de Barcelona , Barcelona , Spain.,b Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) , Barcelona , Spain.,c Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Spain
| | - Esther Pérez-Navarro
- a Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències , Universitat de Barcelona , Barcelona , Spain.,b Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) , Barcelona , Spain.,c Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Spain
| | - Jordi Alberch
- a Departament de Biomedicina, Facultat de Medicina i Ciències de la Salut, Institut de Neurociències , Universitat de Barcelona , Barcelona , Spain.,b Institut d'Investigacions Biomèdiques August Pi i Sunyer (IDIBAPS) , Barcelona , Spain.,c Centro de Investigación Biomédica en Red sobre Enfermedades Neurodegenerativas (CIBERNED) , Spain
| |
Collapse
|
13
|
She X, Lu X, Li T, Sun J, Liang J, Zhai Y, Yang S, Gu Q, Wei F, Zhu H, Wang F, Luo X, Sun X. Inhibition of Mitochondrial Fission Preserves Photoreceptors after Retinal Detachment. THE AMERICAN JOURNAL OF PATHOLOGY 2018; 188:1713-1722. [PMID: 29684364 DOI: 10.1016/j.ajpath.2018.03.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/04/2017] [Revised: 02/23/2018] [Accepted: 03/26/2018] [Indexed: 01/13/2023]
Abstract
Photoreceptor degeneration is a leading cause of visual impairment worldwide. Separation of neurosensory retina from the underlying retinal pigment epithelium is a prominent feature preceding photoreceptor degeneration in a variety of retinal diseases. Although ophthalmic surgical procedures have been well developed to restore retinal structures, postoperative patients usually experience progressive photoreceptor degeneration and irreversible vision loss that is incurable at present. Previous studies point to a critical role of mitochondria-mediated apoptotic pathway in photoreceptor degeneration, but the upstream triggers remain largely unexplored. In this study, we show that after experimental retinal detachment induction, photoreceptors activate dynamin-related protein 1 (Drp1)-dependent mitochondrial fission pathway and subsequent apoptotic cascades. Mechanistically, endogenous reactive oxygen species (ROS) are necessary for Drp1 activation in vivo, and exogenous ROS insult is sufficient to activate Drp1-dependent mitochondrial fission in cultured photoreceptors. Accordingly, inhibition of Drp1 activity effectively preserves mitochondrial integrity and rescues photoreceptors. Collectively, our data delineate an ROS-Drp1-mitochondria axis that promotes photoreceptor degeneration in retinal diseased models.
Collapse
Affiliation(s)
- Xiangjun She
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai
| | - Xinmin Lu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai
| | - Tong Li
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai
| | - Junran Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai
| | - Jian Liang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai
| | - Yuanqi Zhai
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai
| | - Shiqi Yang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai
| | - Qing Gu
- Shanghai Key Laboratory of Fundus Diseases, Shanghai, People's Republic of China
| | - Fang Wei
- Shanghai Key Laboratory of Fundus Diseases, Shanghai, People's Republic of China
| | - Hong Zhu
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai
| | - Fenghua Wang
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai
| | - Xueting Luo
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai; Shanghai Key Laboratory of Fundus Diseases, Shanghai, People's Republic of China.
| | - Xiaodong Sun
- Department of Ophthalmology, Shanghai General Hospital (Shanghai First People's Hospital), Shanghai Jiao Tong University School of Medicine, Shanghai; Shanghai Engineering Center for Visual Science and Photomedicine, Shanghai; Shanghai Key Laboratory of Fundus Diseases, Shanghai, People's Republic of China.
| |
Collapse
|
14
|
Wongprayoon P, Govitrapong P. Melatonin as a mitochondrial protector in neurodegenerative diseases. Cell Mol Life Sci 2017; 74:3999-4014. [PMID: 28791420 PMCID: PMC11107580 DOI: 10.1007/s00018-017-2614-x] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2017] [Accepted: 08/03/2017] [Indexed: 12/19/2022]
Abstract
Mitochondria are crucial organelles as their role in cellular energy production of eukaryotes. Because the brain cells demand high energy for maintaining their normal activities, disturbances in mitochondrial physiology may lead to neuropathological events underlying neurodegenerative conditions such as Alzheimer's disease, Parkinson's disease and Huntington's disease. Melatonin is an endogenous compound with a variety of physiological roles. In addition, it possesses potent antioxidant properties which effectively play protective roles in several pathological conditions. Several lines of evidence also reveal roles of melatonin in mitochondrial protection, which could prevent development and progression of neurodegeneration. Since the mitochondrial dysfunction is a primary event in neurodegeneration, the neuroprotection afforded by melatonin is thereby more effective in early stages of the diseases. This article reviews mechanisms which melatonin exerts its protective roles on mitochondria as a potential therapeutic strategy against neurodegenerative disorders.
Collapse
Affiliation(s)
- Pawaris Wongprayoon
- Department of Biopharmacy, Faculty of Pharmacy, Silpakorn University, Nakhon Pathom, 73000, Thailand
| | - Piyarat Govitrapong
- Research Center for Neuroscience, Institute of Molecular Biosciences, Mahidol University, Nakhon Pathom, 73170, Thailand.
- Chulabhorn Graduate Institute, Chulabhorn Royal Academy, Bangkok, 10210, Thailand.
| |
Collapse
|
15
|
Cobalt inhibits motility of axonal mitochondria and induces axonal degeneration in cultured dorsal root ganglion cells of rat. Cell Biol Toxicol 2017; 34:93-107. [PMID: 28656345 DOI: 10.1007/s10565-017-9402-0] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/18/2017] [Accepted: 06/15/2017] [Indexed: 10/19/2022]
Abstract
Cobalt is a trace element that localizes in the human body as cobalamin, also known as vitamin B12. Excessive cobalt exposure induces a peripheral neuropathy, the mechanisms of which are yet to be elucidated. We investigated how cobalt may affect mitochondrial motility in primary cultures of rat dorsal root ganglion (DRG). We observed mitochondrial motility by time-lapse imaging after DsRed2 tagging via lentivirus, mitochondrial structure using transmission electron microscopy (TEM), and axonal swelling using immunocytochemical staining. The concentration of cobaltous ion (Co2+) required to significantly suppress mitochondrial motility is lower than that required to induce axonal swelling following a 24-h treatment. Exposure to relatively low concentrations of Co2+ for 48 h suppressed mitochondrial motility without leading to axonal swelling. TEM images indicated that Co2+ induces mitochondrial destruction. Our results show that destruction of the axonal mitochondria precedes the axonal degeneration induced by Co2+ exposure.
Collapse
|
16
|
Misery loves company - shared features of neurodegenerative disorders. Biochem Biophys Res Commun 2017; 483:979-980. [PMID: 28189152 DOI: 10.1016/j.bbrc.2017.01.099] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
|
17
|
Mdivi-1 Alleviates Early Brain Injury After Experimental Subarachnoid Hemorrhage in Rats, Possibly via Inhibition of Drp1-Activated Mitochondrial Fission and Oxidative Stress. Neurochem Res 2017; 42:1449-1458. [DOI: 10.1007/s11064-017-2201-4] [Citation(s) in RCA: 44] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2017] [Revised: 01/31/2017] [Accepted: 02/02/2017] [Indexed: 01/06/2023]
|