1
|
Picker SM, Parker G, Gissen P. Features of Congenital Arthrogryposis Due to Abnormalities in Collagen Homeostasis, a Scoping Review. Int J Mol Sci 2023; 24:13545. [PMID: 37686358 PMCID: PMC10487887 DOI: 10.3390/ijms241713545] [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: 07/15/2023] [Revised: 08/30/2023] [Accepted: 08/30/2023] [Indexed: 09/10/2023] Open
Abstract
Congenital arthrogryposis (CA) refers to the presence of multiple contractures at birth. It is a feature of several inherited syndromes, notable amongst them are disorders of collagen formation. This review aims to characterize disorders that directly or indirectly impact collagen structure and function leading to CA in search for common phenotypic or pathophysiological features, possible genotype-phenotype correlation, and potential novel treatment approaches based on a better understanding of the underlying pathomechanism. Nine genes, corresponding to five clinical phenotypes, were identified after a literature search. The most notable trend was the extreme phenotype variability. Clinical features across all syndromes ranged from subtle with minimal congenital contractures, to severe with multiple congenital contractures and extra-articular features including skin, respiratory, or other manifestations. Five of the identified genes were involved in the function of the Lysyl Hydroxylase 2 or 3 enzymes, which enable the hydroxylation and/or glycosylation of lysyl residues to allow the formation of the collagen superstructure. Whilst current treatment approaches are post-natal surgical correction, there are also potential in-utero therapies being developed. Cyclosporin A showed promise in treating collagen VI disorders although there is an associated risk of immunosuppression. The treatments that could be in the clinical trials soon are the splice correction therapies in collagen VI-related disorders.
Collapse
Affiliation(s)
| | - George Parker
- Newcastle University Medical School, Newcastle NE2 4HH, UK;
| | - Paul Gissen
- National Institute for Health Research Great Ormond Street Hospital Biomedical Research Centre, University College London, London WC1N 1EH, UK
- Genetics and Genomic Medicine Department, Great Ormond Street Institute of Child Health, University College London, London WC1N 1EH, UK
| |
Collapse
|
2
|
Reggiani C, Marcucci L. A controversial issue: Can mitochondria modulate cytosolic calcium and contraction of skeletal muscle fibers? J Gen Physiol 2022; 154:213356. [PMID: 35849108 PMCID: PMC9297197 DOI: 10.1085/jgp.202213167] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Mitochondria are characterized by a high capacity to accumulate calcium thanks to the electrochemical gradient created by the extrusion of protons in the respiratory chain. Thereby calcium can enter crossing the inner mitochondrial membrane via MCU complex, a high-capacity, low-affinity transport mechanism. Calcium uptake serves numerous purposes, among them the regulation of three dehydrogenases of the citric cycle, apoptosis via permeability transition, and, in some cell types, modulation of cytosolic calcium transients. This Review is focused on mitochondrial calcium uptake in skeletal muscle fibers and aims to reanalyze its functional impact. In particular, we ask whether mitochondrial calcium uptake is relevant for the control of cytosolic calcium transients and therefore of contractile performance. Recent data suggest that this may be the case, at least in particular conditions, as modified expression of MCU complex subunits or of proteins involved in mitochondrial dynamics and ablation of the main cytosolic calcium buffer, parvalbumin.
Collapse
Affiliation(s)
- Carlo Reggiani
- Department of Biomedical Sciences, University of Padova, Padova, Italy,Science and Research Center Koper, Institute for Kinesiology Research, Koper, Slovenia,Correspondence to Carlo Reggiani:
| | - Lorenzo Marcucci
- Department of Biomedical Sciences, University of Padova, Padova, Italy,Center for Biosystems Dynamics Research, RIKEN, Suita, Japan
| |
Collapse
|
3
|
González-Jamett A, Vásquez W, Cifuentes-Riveros G, Martínez-Pando R, Sáez JC, Cárdenas AM. Oxidative Stress, Inflammation and Connexin Hemichannels in Muscular Dystrophies. Biomedicines 2022; 10:biomedicines10020507. [PMID: 35203715 PMCID: PMC8962419 DOI: 10.3390/biomedicines10020507] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2022] [Revised: 02/13/2022] [Accepted: 02/15/2022] [Indexed: 12/16/2022] Open
Abstract
Muscular dystrophies (MDs) are a heterogeneous group of congenital neuromuscular disorders whose clinical signs include myalgia, skeletal muscle weakness, hypotonia, and atrophy that leads to progressive muscle disability and loss of ambulation. MDs can also affect cardiac and respiratory muscles, impairing life-expectancy. MDs in clude Duchenne muscular dystrophy, Emery-Dreifuss muscular dystrophy, facioscapulohumeral muscular dystrophy and limb-girdle muscular dystrophy. These and other MDs are caused by mutations in genes that encode proteins responsible for the structure and function of skeletal muscles, such as components of the dystrophin-glycoprotein-complex that connect the sarcomeric-actin with the extracellular matrix, allowing contractile force transmission and providing stability during muscle contraction. Consequently, in dystrophic conditions in which such proteins are affected, muscle integrity is disrupted, leading to local inflammatory responses, oxidative stress, Ca2+-dyshomeostasis and muscle degeneration. In this scenario, dysregulation of connexin hemichannels seem to be an early disruptor of the homeostasis that further plays a relevant role in these processes. The interaction between all these elements constitutes a positive feedback loop that contributes to the worsening of the diseases. Thus, we discuss here the interplay between inflammation, oxidative stress and connexin hemichannels in the progression of MDs and their potential as therapeutic targets.
Collapse
Affiliation(s)
- Arlek González-Jamett
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (W.V.); (J.C.S.)
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile; (G.C.-R.); (R.M.-P.)
- Correspondence: (A.G.-J.); (A.M.C.)
| | - Walter Vásquez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (W.V.); (J.C.S.)
| | - Gabriela Cifuentes-Riveros
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile; (G.C.-R.); (R.M.-P.)
| | - Rafaela Martínez-Pando
- Escuela de Química y Farmacia, Facultad de Farmacia, Universidad de Valparaíso, Valparaíso 2360102, Chile; (G.C.-R.); (R.M.-P.)
| | - Juan C. Sáez
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (W.V.); (J.C.S.)
| | - Ana M. Cárdenas
- Centro Interdisciplinario de Neurociencia de Valparaíso, Facultad de Ciencias, Universidad de Valparaíso, Valparaíso 2360102, Chile; (W.V.); (J.C.S.)
- Correspondence: (A.G.-J.); (A.M.C.)
| |
Collapse
|
4
|
Olowofolahan AO, Adeosun OA, Olorunsogo OO. Monosodium Glutamate Induces Cytotoxicity in Rat Liver via Mitochondrial Permeability Transition Pore Opening. Cell Biochem Biophys 2020; 78:429-437. [PMID: 32964329 DOI: 10.1007/s12013-020-00944-z] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 09/14/2020] [Indexed: 01/06/2023]
Abstract
Monosodium glutamate (MSG) is a major food additive used as a flavor enhancer. A lot of controversies have been generated over the use of MSG. The present study therefore investigated whether MSG would induce cytotoxicity via the induction of mitochondrial permeability transition (mPT) pore opening. 36 male albino rats were used for this study. The rats were equally divided into six groups: group I is the control while group II, III, IV, V, and VI were orally treated with MSG (25, 50, 100, 200, and 400 mg/kg) daily for 28 days. The opening of the pore, cytochrome c release, mitochondrial ATPase activity, mitochondrial lipid peroxidation and hepatic DNA fragmentation were determined spectrophotometrically. Histological assessment of prostate and brain was carried out. The results show that MSG at concentrations ≤30 µg/ml did not induce mPT pore opening while higher concentrations caused significant induction of pore opening. Also, at lower doses (25 and 50 mg/kg), MSG did not cause any significant induction of mPT pore opening while at higher doses, there were significant induction of pore opening. Similar trend of results was recorded for cytochrome c release, mitochondrial ATPase activity and lipid peroxidation. The histological results show that at low doses (25 and 50 mg/kg), no significant lesion was observed while higher doses caused benign prostatic hyperplasia (BPH) in the prostate and necrotic damage in the brain. MSG administration at low dose is tolerable while high doses induce cytotoxicity via mPT pore opening.
Collapse
Affiliation(s)
- Adeola Oluwakemi Olowofolahan
- Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Nigeria.
| | - Oluwatobi Andrew Adeosun
- Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Nigeria
| | - Olufunso Olabode Olorunsogo
- Department of Biochemistry, Faculty of Basic Medical Sciences, College of Medicine, University of Ibadan, Ibadan, Nigeria
| |
Collapse
|
5
|
Debattisti V, Horn A, Singh R, Seifert EL, Hogarth MW, Mazala DA, Huang KT, Horvath R, Jaiswal JK, Hajnóczky G. Dysregulation of Mitochondrial Ca 2+ Uptake and Sarcolemma Repair Underlie Muscle Weakness and Wasting in Patients and Mice Lacking MICU1. Cell Rep 2020; 29:1274-1286.e6. [PMID: 31665639 PMCID: PMC7007691 DOI: 10.1016/j.celrep.2019.09.063] [Citation(s) in RCA: 58] [Impact Index Per Article: 14.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/12/2019] [Revised: 08/07/2019] [Accepted: 09/20/2019] [Indexed: 01/29/2023] Open
Abstract
Muscle function is regulated by Ca2+, which mediates excitation-contraction coupling, energy metabolism, adaptation to exercise, and sarcolemmal repair. Several of these actions rely on Ca2+ delivery to the mitochondrial matrix via the mitochondrial Ca2+ uniporter, the pore of which is formed by mitochondrial calcium uniporter (MCU). MCU's gatekeeping and cooperative activation are controlled by MICU1. Loss-of-protein mutation in MICU1 causes a neuromuscular disease. To determine the mechanisms underlying the muscle impairments, we used MICU1 patient cells and skeletal muscle-specific MICU1 knockout mice. Both these models show a lower threshold for MCU-mediated Ca2+ uptake. Lack of MICU1 is associated with impaired mitochondrial Ca2+ uptake during excitation-contraction, aerobic metabolism impairment, muscle weakness, fatigue, and myofiber damage during physical activity. MICU1 deficit compromises mitochondrial Ca2+ uptake during sarcolemmal injury, which causes ineffective repair of the damaged myofibers. Thus, dysregulation of mitochondrial Ca2+ uptake hampers myofiber contractile function, likely through energy metabolism and membrane repair.
Collapse
Affiliation(s)
- Valentina Debattisti
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Adam Horn
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue Northwest, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA
| | - Raghavendra Singh
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Erin L Seifert
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Marshall W Hogarth
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue Northwest, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA
| | - Davi A Mazala
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue Northwest, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA
| | - Kai Ting Huang
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA
| | - Rita Horvath
- Wellcome Centre for Mitochondrial Research, Institute of Genetic Medicine, Newcastle University, Newcastle upon Tyne, UK
| | - Jyoti K Jaiswal
- Center for Genetic Medicine Research, Children's National Health System, 111 Michigan Avenue Northwest, Washington, DC 20010, USA; Department of Genomics and Precision Medicine, George Washington University School of Medicine and Health Sciences, Washington, DC 20052, USA.
| | - György Hajnóczky
- MitoCare Center for Mitochondrial Imaging Research and Diagnostics, Department of Pathology, Anatomy and Cell Biology, Thomas Jefferson University, Philadelphia, PA, USA.
| |
Collapse
|
6
|
Nath S. A Novel Conceptual Model for the Dual Role of FOF1-ATP Synthase in Cell Life and Cell Death. Biomol Concepts 2020; 11:143-152. [PMID: 32827389 DOI: 10.1515/bmc-2020-0014] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/29/2020] [Accepted: 07/22/2020] [Indexed: 12/31/2022] Open
Abstract
The mitochondrial permeability transition (MPT) has been one of the longstanding enigmas in biology. Its cause is currently at the center of an extensive scientific debate, and several hypotheses on its molecular nature have been put forward. The present view holds that the transition arises from the opening of a high-conductance channel in the energy-transducing membrane, the permeability transition pore (PTP), also called the mitochondrial megachannel or the multiconductance channel (MMC). Here, the novel hypothesis is proposed that the aqueous access channels at the interface of the c-ring and the a-subunit of FO in the FOF1-ATP synthase are repurposed during induction of apoptosis and constitute the elusive PTP/ MMC. A unifying principle based on regulation by local potentials is advanced to rationalize the action of the myriad structurally and chemically diverse inducers and inhibitors of PTP/MMC. Experimental evidence in favor of the hypothesis and its differences from current models of PTP/MMC are summarized. The hypothesis explains in considerable detail how the binding of Ca2+ to a β-catalytic site (site 3) in the F1 portion of ATP synthase triggers the opening of the PTP/MMC. It is also shown to connect to longstanding proposals within Nath's torsional mechanism of energy transduction and ATP synthesis as to how the binding of MgADP to site 3 does not induce PTP/MMC, but instead catalyzes physiological ATP synthesis in cell life. In the author's knowledge, this is the first model that explains how Ca2+ transforms the FOF1-ATP synthase from an exquisite energy-conserving enzyme in cell life into an energy-dissipating structure that promotes cell death. This has major implications for basic as well as for clinical research, such as for the development of drugs that target the MPT, given the established role of PTP/MMC dysregulation in cancer, ischemia, cardiac hypertrophy, and various neurodegenerative diseases.
Collapse
Affiliation(s)
- Sunil Nath
- Department of Biochemical Engineering and Biotechnology, Indian Institute of Technology Delhi, Hauz Khas, New Delhi 110016, India
| |
Collapse
|
7
|
Abstract
Adult cardiomyocytes are postmitotic cells that undergo very limited cell division. Thus, cardiomyocyte death as occurs during myocardial infarction has very detrimental consequences for the heart. Mitochondria have emerged as an important regulator of cardiovascular health and disease. Mitochondria are well established as bioenergetic hubs for generating ATP but have also been shown to regulate cell death pathways. Indeed many of the same signals used to regulate metabolism and ATP production, such as calcium and reactive oxygen species, are also key regulators of mitochondrial cell death pathways. It is widely hypothesized that an increase in calcium and reactive oxygen species activate a large conductance channel in the inner mitochondrial membrane known as the PTP (permeability transition pore) and that opening of this pore leads to necroptosis, a regulated form of necrotic cell death. Strategies to reduce PTP opening either by inhibition of PTP or inhibiting the rise in mitochondrial calcium or reactive oxygen species that activate PTP have been proposed. A major limitation of inhibiting the PTP is the lack of knowledge about the identity of the protein(s) that form the PTP and how they are activated by calcium and reactive oxygen species. This review will critically evaluate the candidates for the pore-forming unit of the PTP and discuss recent data suggesting that assumption that the PTP is formed by a single molecular identity may need to be reconsidered.
Collapse
Affiliation(s)
- Tyler M Bauer
- Laboratory of Cardiac Physiology, National Heart, Lung and Blood Institute, Bethesda, MD
| | - Elizabeth Murphy
- Laboratory of Cardiac Physiology, National Heart, Lung and Blood Institute, Bethesda, MD
| |
Collapse
|
8
|
Human muscle pathology is associated with altered phosphoprotein profile of mitochondrial proteins in the skeletal muscle. J Proteomics 2020; 211:103556. [PMID: 31655151 DOI: 10.1016/j.jprot.2019.103556] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2019] [Revised: 10/08/2019] [Accepted: 10/17/2019] [Indexed: 12/29/2022]
Abstract
Analysis of human muscle diseases highlights the role of mitochondrial dysfunction in the skeletal muscle. Our previous work revealed that diverse upstream events correlated with altered mitochondrial proteome in human muscle biopsies. However, several proteins showed relatively unchanged expression suggesting that post-translational modifications, mainly protein phosphorylation could influence their activity and regulate mitochondrial processes. We conducted mitochondrial phosphoprotein profiling, by proteomics approach, of healthy human skeletal muscle (n = 10) and three muscle diseases (n = 10 each): Dysferlinopathy, Polymyositis and Distal Myopathy with Rimmed Vacuoles. Healthy human muscle mitochondrial proteins displayed 253 phosphorylation sites (phosphosites), which contributed to metabolic and redox processes and mitochondrial organization etc. Electron transport chain complexes accounted for 84 phosphosites. Muscle pathologies displayed 33 hyperphosphorylated and 14 hypophorphorylated sites with only 5 common proteins, indicating varied phosphorylation profile across muscle pathologies. Molecular modelling revealed altered local structure in the phosphorylated sites of Voltage-Dependent Anion Channel 1 and complex V subunit ATP5B1. Molecular dynamics simulations in complex I subunits NDUFV1, NDUFS1 and NDUFV2 revealed that phosphorylation induced structural alterations thereby influencing electron transfer and potentially altering enzyme activity. We propose that altered phosphorylation at specific sites could regulate mitochondrial protein function in the skeletal muscle during physiological and pathological processes.
Collapse
|
9
|
Schiavone M, Zulian A, Menazza S, Petronilli V, Argenton F, Merlini L, Sabatelli P, Bernardi P. Alisporivir rescues defective mitochondrial respiration in Duchenne muscular dystrophy. Pharmacol Res 2017; 125:122-131. [DOI: 10.1016/j.phrs.2017.09.001] [Citation(s) in RCA: 30] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/26/2017] [Revised: 09/05/2017] [Accepted: 09/05/2017] [Indexed: 01/09/2023]
|
10
|
Mitochondrial permeability transition pore: sensitivity to opening and mechanistic dependence on substrate availability. Sci Rep 2017; 7:10492. [PMID: 28874733 PMCID: PMC5585167 DOI: 10.1038/s41598-017-10673-8] [Citation(s) in RCA: 91] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2017] [Accepted: 08/11/2017] [Indexed: 12/14/2022] Open
Abstract
Mitochondrial Ca2+ uptake has a key role in cellular Ca2+ homeostasis. Excessive matrix Ca2+ concentrations, especially when coincident with oxidative stress, precipitate opening of an inner mitochondrial membrane, high-conductance channel: the mitochondrial permeability transition pore (mPTP). mPTP opening has been implicated as a final cell death pathway in numerous diseases and therefore understanding conditions dictating mPTP opening is crucial for developing targeted therapies. Here, we have investigated the impact of mitochondrial metabolic state on the probability and consequences of mPTP opening. Isolated mitochondria were energised using NADH- or FADH2-linked substrates. The functional consequences of Ca2+-induced mPTP opening were assessed by Ca2+ retention capacity, using fluorescence-based analysis, and simultaneous measurements of mitochondrial Ca2+ handling, membrane potential, respiratory rate and production of reactive oxygen species (ROS). Succinate-induced, membrane potential-dependent reverse electron transfer sensitised mitochondria to mPTP opening. mPTP-induced depolarisation under succinate subsequently inhibited reverse electron transfer. Complex I-driven respiration was reduced after mPTP opening but sustained in the presence of complex II-linked substrates, consistent with inhibition of complex I-supported respiration by leakage of matrix NADH. Additionally, ROS generated at complex III did not sensitise mitochondria to mPTP opening. Thus, cellular metabolic fluxes and metabolic environment dictate mitochondrial functional response to Ca2+ overload.
Collapse
|
11
|
Briston T, Lewis S, Koglin M, Mistry K, Shen Y, Hartopp N, Katsumata R, Fukumoto H, Duchen MR, Szabadkai G, Staddon JM, Roberts M, Powney B. Identification of ER-000444793, a Cyclophilin D-independent inhibitor of mitochondrial permeability transition, using a high-throughput screen in cryopreserved mitochondria. Sci Rep 2016; 6:37798. [PMID: 27886240 PMCID: PMC5122887 DOI: 10.1038/srep37798] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/26/2016] [Accepted: 11/02/2016] [Indexed: 12/19/2022] Open
Abstract
Growing evidence suggests persistent mitochondrial permeability transition pore (mPTP) opening is a key pathophysiological event in cell death underlying a variety of diseases. While it has long been clear the mPTP is a druggable target, current agents are limited by off-target effects and low therapeutic efficacy. Therefore identification and development of novel inhibitors is necessary. To rapidly screen large compound libraries for novel mPTP modulators, a method was exploited to cryopreserve large batches of functionally active mitochondria from cells and tissues. The cryopreserved mitochondria maintained respiratory coupling and ATP synthesis, Ca2+ uptake and transmembrane potential. A high-throughput screen (HTS), using an assay of Ca2+-induced mitochondrial swelling in the cryopreserved mitochondria identified ER-000444793, a potent inhibitor of mPTP opening. Further evaluation using assays of Ca2+-induced membrane depolarisation and Ca2+ retention capacity also indicated that ER-000444793 acted as an inhibitor of the mPTP. ER-000444793 neither affected cyclophilin D (CypD) enzymatic activity, nor displaced of CsA from CypD protein, suggesting a mechanism independent of CypD inhibition. Here we identified a novel, CypD-independent inhibitor of the mPTP. The screening approach and compound described provides a workflow and additional tool to aid the search for novel mPTP modulators and to help understand its molecular nature.
Collapse
Affiliation(s)
- Thomas Briston
- UCL Collaboration Research Group, NGM-PCU, Eisai Ltd., Hatfield, UK
| | - Sian Lewis
- UCL Collaboration Research Group, NGM-PCU, Eisai Ltd., Hatfield, UK
| | - Mumta Koglin
- UCL Collaboration Research Group, NGM-PCU, Eisai Ltd., Hatfield, UK
| | - Kavita Mistry
- UCL Collaboration Research Group, NGM-PCU, Eisai Ltd., Hatfield, UK
| | - Yongchun Shen
- Next Generation Systems CFU, Eisai Inc., Andover, MA, USA
| | - Naomi Hartopp
- UCL Collaboration Research Group, NGM-PCU, Eisai Ltd., Hatfield, UK
| | | | - Hironori Fukumoto
- NGM-PCU, Eisai Co. Ltd., Tsukuba Research Laboratories, Tsukuba, Japan
| | - Michael R. Duchen
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Gyorgy Szabadkai
- Department of Cell and Developmental Biology, University College London, London, UK
- Department of Biomedical Sciences, University of Padua, Padua, Italy
| | - James M. Staddon
- UCL Collaboration Research Group, NGM-PCU, Eisai Ltd., Hatfield, UK
| | - Malcolm Roberts
- UCL Collaboration Research Group, NGM-PCU, Eisai Ltd., Hatfield, UK
| | - Ben Powney
- UCL Collaboration Research Group, NGM-PCU, Eisai Ltd., Hatfield, UK
| |
Collapse
|
12
|
Biasutto L, Azzolini M, Szabò I, Zoratti M. The mitochondrial permeability transition pore in AD 2016: An update. BIOCHIMICA ET BIOPHYSICA ACTA 2016; 1863:2515-30. [PMID: 26902508 DOI: 10.1016/j.bbamcr.2016.02.012] [Citation(s) in RCA: 91] [Impact Index Per Article: 11.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/17/2015] [Revised: 02/04/2016] [Accepted: 02/05/2016] [Indexed: 12/13/2022]
Abstract
Over the past 30years the mitochondrial permeability transition - the permeabilization of the inner mitochondrial membrane due to the opening of a wide pore - has progressed from being considered a curious artifact induced in isolated mitochondria by Ca(2+) and phosphate to a key cell-death-inducing process in several major pathologies. Its relevance is by now universally acknowledged and a pharmacology targeting the phenomenon is being developed. The molecular nature of the pore remains to this day uncertain, but progress has recently been made with the identification of the FOF1 ATP synthase as the probable proteic substrate. Researchers sharing this conviction are however divided into two camps: these believing that only the ATP synthase dimers or oligomers can form the pore, presumably in the contact region between monomers, and those who consider that the ring-forming c subunits in the FO sector actually constitute the walls of the pore. The latest development is the emergence of a new candidate: Spastic Paraplegia 7 (SPG7), a mitochondrial AAA-type membrane protease which forms a 6-stave barrel. This review summarizes recent developments of research on the pathophysiological relevance and on the molecular nature of the mitochondrial permeability transition pore. This article is part of a Special Issue entitled: Mitochondrial Channels edited by Pierre Sonveaux, Pierre Maechler and Jean-Claude Martinou.
Collapse
Affiliation(s)
- Lucia Biasutto
- CNR Neuroscience Institute, Viale G. Colombo 3, 35121 Padova, Italy; University of Padova, Department of Biomedical Sciences, Viale G. Colombo 3, 35121 Padova, Italy
| | - Michele Azzolini
- CNR Neuroscience Institute, Viale G. Colombo 3, 35121 Padova, Italy; University of Padova, Department of Biomedical Sciences, Viale G. Colombo 3, 35121 Padova, Italy
| | - Ildikò Szabò
- CNR Neuroscience Institute, Viale G. Colombo 3, 35121 Padova, Italy; University of Padova, Department of Biology, Viale G. Colombo 3, 35121 Padova, Italy
| | - Mario Zoratti
- CNR Neuroscience Institute, Viale G. Colombo 3, 35121 Padova, Italy; University of Padova, Department of Biomedical Sciences, Viale G. Colombo 3, 35121 Padova, Italy.
| |
Collapse
|
13
|
Zulian A, Tagliavini F, Rizzo E, Pellegrini C, Sardone F, Zini N, Maraldi NM, Santi S, Faldini C, Merlini L, Petronilli V, Bernardi P, Sabatelli P. Melanocytes from Patients Affected by Ullrich Congenital Muscular Dystrophy and Bethlem Myopathy have Dysfunctional Mitochondria That Can be Rescued with Cyclophilin Inhibitors. Front Aging Neurosci 2014; 6:324. [PMID: 25477819 PMCID: PMC4238408 DOI: 10.3389/fnagi.2014.00324] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2014] [Accepted: 11/06/2014] [Indexed: 11/13/2022] Open
Abstract
Ullrich congenital muscular dystrophy and Bethlem myopathy are caused by mutations in collagen VI (ColVI) genes, which encode an extracellular matrix protein; yet, mitochondria play a major role in disease pathogenesis through a short circuit caused by inappropriate opening of the permeability transition pore, a high-conductance channel, which causes a shortage in ATP production. We find that melanocytes do not produce ColVI yet they bind it at the cell surface, suggesting that this protein may play a trophic role and that its absence may cause lesions similar to those seen in skeletal muscle. We show that mitochondria in melanocytes of Ullrich congenital muscular dystrophy and Bethlem myopathy patients display increased size, reduced matrix density, and disrupted cristae, findings that suggest a functional impairment. In keeping with this hypothesis, mitochondria (i) underwent anomalous depolarization after inhibition of the F-ATP synthase with oligomycin, and (ii) displayed decreased respiratory reserve capacity. The non-immunosuppressive cyclophilin inhibitor NIM811 prevented mitochondrial depolarization in response to oligomycin in melanocytes from both Ullrich congenital muscular dystrophy and Bethlem myopathy patients, and partially restored the respiratory reserve of melanocytes from one Bethlem myopathy patient. These results match our recent findings on melanocytes from patients affected by Duchenne muscular dystrophy (Pellegrini et al., 2013), and suggest that skin biopsies may represent a minimally invasive tool to investigate mitochondrial dysfunction and to evaluate drug efficacy in ColVI-related myopathies and possibly in other muscle wasting conditions like aging sarcopenia.
Collapse
Affiliation(s)
- Alessandra Zulian
- Department of Biomedical Sciences, University of Padova , Padova , Italy ; CNR Neuroscience Institute , Padova , Italy
| | - Francesca Tagliavini
- CNR National Research Council of Italy, Institute of Molecular Genetics , Bologna , Italy ; SC Laboratory of Musculoskeletal Cell Biology, IOR , Bologna , Italy
| | - Erika Rizzo
- Department of Biomedical Sciences, University of Padova , Padova , Italy ; CNR Neuroscience Institute , Padova , Italy
| | | | - Francesca Sardone
- CNR National Research Council of Italy, Institute of Molecular Genetics , Bologna , Italy ; SC Laboratory of Musculoskeletal Cell Biology, IOR , Bologna , Italy
| | - Nicoletta Zini
- CNR National Research Council of Italy, Institute of Molecular Genetics , Bologna , Italy ; SC Laboratory of Musculoskeletal Cell Biology, IOR , Bologna , Italy
| | - Nadir Mario Maraldi
- CNR National Research Council of Italy, Institute of Molecular Genetics , Bologna , Italy
| | - Spartaco Santi
- CNR National Research Council of Italy, Institute of Molecular Genetics , Bologna , Italy ; SC Laboratory of Musculoskeletal Cell Biology, IOR , Bologna , Italy
| | - Cesare Faldini
- Rizzoli Orthopaedic Institute, University of Bologna , Bologna , Italy
| | - Luciano Merlini
- SC Laboratory of Musculoskeletal Cell Biology, IOR , Bologna , Italy
| | - Valeria Petronilli
- Department of Biomedical Sciences, University of Padova , Padova , Italy ; CNR Neuroscience Institute , Padova , Italy
| | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padova , Padova , Italy ; CNR Neuroscience Institute , Padova , Italy
| | - Patrizia Sabatelli
- CNR National Research Council of Italy, Institute of Molecular Genetics , Bologna , Italy ; SC Laboratory of Musculoskeletal Cell Biology, IOR , Bologna , Italy
| |
Collapse
|
14
|
Sorato E, Menazza S, Zulian A, Sabatelli P, Gualandi F, Merlini L, Bonaldo P, Canton M, Bernardi P, Di Lisa F. Monoamine oxidase inhibition prevents mitochondrial dysfunction and apoptosis in myoblasts from patients with collagen VI myopathies. Free Radic Biol Med 2014; 75:40-7. [PMID: 25017965 PMCID: PMC4180008 DOI: 10.1016/j.freeradbiomed.2014.07.006] [Citation(s) in RCA: 36] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/20/2014] [Revised: 06/24/2014] [Accepted: 07/03/2014] [Indexed: 11/30/2022]
Abstract
Although mitochondrial dysfunction and oxidative stress have been proposed to play a crucial role in several types of muscular dystrophy (MD), whether a causal link between these two alterations exists remains an open question. We have documented that mitochondrial dysfunction through opening of the permeability transition pore plays a key role in myoblasts from patients as well as in mouse models of MD, and that oxidative stress caused by monoamine oxidases (MAO) is involved in myofiber damage. In the present study we have tested whether MAO-dependent oxidative stress is a causal determinant of mitochondrial dysfunction and apoptosis in myoblasts from patients affected by collagen VI myopathies. We find that upon incubation with hydrogen peroxide or the MAO substrate tyramine myoblasts from patients upregulate MAO-B expression and display a significant rise in reactive oxygen species (ROS) levels, with concomitant mitochondrial depolarization. MAO inhibition by pargyline significantly reduced both ROS accumulation and mitochondrial dysfunction, and normalized the increased incidence of apoptosis in myoblasts from patients. Thus, MAO-dependent oxidative stress is causally related to mitochondrial dysfunction and cell death in myoblasts from patients affected by collagen VI myopathies, and inhibition of MAO should be explored as a potential treatment for these diseases.
Collapse
Affiliation(s)
- E Sorato
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - S Menazza
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - A Zulian
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - P Sabatelli
- Institute of Molecular Genetics, National Research Council of Italy, 40136 Bologna, Italy
| | - F Gualandi
- Department of Medical Science, Section of Medical Genetics, University of Ferrara, 44100 Ferrara, Italy
| | - L Merlini
- Laboratory of Musculoskeletal Cell Biology, Istituto Ortopedico Rizzoli, IRCCS, 40136 Bologna, Italy
| | - P Bonaldo
- Department of Molecular Medicine, University of Padova, 35131 Padova, Italy
| | - M Canton
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy
| | - P Bernardi
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy; Neuroscience Institute, National Research Council of Italy, 35131 Padova, Italy
| | - F Di Lisa
- Department of Biomedical Sciences, University of Padova, 35131 Padova, Italy; Neuroscience Institute, National Research Council of Italy, 35131 Padova, Italy.
| |
Collapse
|
15
|
Abstract
The field of mitochondrial ion channels has recently seen substantial progress, including the molecular identification of some of the channels. An integrative approach using genetics, electrophysiology, pharmacology, and cell biology to clarify the roles of these channels has thus become possible. It is by now clear that many of these channels are important for energy supply by the mitochondria and have a major impact on the fate of the entire cell as well. The purpose of this review is to provide an up-to-date overview of the electrophysiological properties, molecular identity, and pathophysiological functions of the mitochondrial ion channels studied so far and to highlight possible therapeutic perspectives based on current information.
Collapse
|
16
|
Zulian A, Rizzo E, Schiavone M, Palma E, Tagliavini F, Blaauw B, Merlini L, Maraldi NM, Sabatelli P, Braghetta P, Bonaldo P, Argenton F, Bernardi P. NIM811, a cyclophilin inhibitor without immunosuppressive activity, is beneficial in collagen VI congenital muscular dystrophy models. Hum Mol Genet 2014; 23:5353-63. [DOI: 10.1093/hmg/ddu254] [Citation(s) in RCA: 54] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
|
17
|
Da-Ré C, De Pittà C, Zordan MA, Teza G, Nestola F, Zeviani M, Costa R, Bernardi P. UCP4C mediates uncoupled respiration in larvae of Drosophila melanogaster. EMBO Rep 2014; 15:586-91. [PMID: 24639557 PMCID: PMC4210097 DOI: 10.1002/embr.201337972] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2013] [Revised: 02/11/2014] [Accepted: 02/13/2014] [Indexed: 01/21/2023] Open
Abstract
Larvae of Drosophila melanogaster reared at 23°C and switched to 14°C for 1 h are 0.5°C warmer than the surrounding medium. In keeping with dissipation of energy, respiration of Drosophila melanogaster larvae cannot be decreased by the F-ATPase inhibitor oligomycin or stimulated by protonophore. Silencing of Ucp4C conferred sensitivity of respiration to oligomycin and uncoupler, and prevented larva-to-adult progression at 15°C but not 23°C. Uncoupled respiration of larval mitochondria required palmitate, was dependent on Ucp4C and was inhibited by guanosine diphosphate. UCP4C is required for development through the prepupal stages at low temperatures and may be an uncoupling protein.
Collapse
Affiliation(s)
- Caterina Da-Ré
- Department of Biology, University of PadovaPadova, Italy
| | | | - Mauro A Zordan
- Department of Biology, University of PadovaPadova, Italy
| | - Giordano Teza
- Department of Geosciences, University of PadovaPadova, Italy
| | | | - Massimo Zeviani
- MRC Mitocondrial Biology Unit, University of CambridgeCambridge, UK
| | - Rodolfo Costa
- Department of Biology, University of PadovaPadova, Italy
| | - Paolo Bernardi
- Department of Biomedical Sciences, Consiglio Nazionale delle Ricerche Institute of Neuroscience, University of PadovaPadova, Italy
| |
Collapse
|
18
|
Gene expression profiling identifies molecular pathways associated with collagen VI deficiency and provides novel therapeutic targets. PLoS One 2013; 8:e77430. [PMID: 24223098 PMCID: PMC3819505 DOI: 10.1371/journal.pone.0077430] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2013] [Accepted: 09/02/2013] [Indexed: 12/25/2022] Open
Abstract
Ullrich congenital muscular dystrophy (UCMD), caused by collagen VI deficiency, is a common congenital muscular dystrophy. At present, the role of collagen VI in muscle and the mechanism of disease are not fully understood. To address this we have applied microarrays to analyse the transcriptome of UCMD muscle and compare it to healthy muscle and other muscular dystrophies. We identified 389 genes which are differentially regulated in UCMD relative to controls. In addition, there were 718 genes differentially expressed between UCMD and dystrophin deficient muscle. In contrast, only 29 genes were altered relative to other congenital muscular dystrophies. Changes in gene expression were confirmed by real-time PCR. The set of regulated genes was analysed by Gene Ontology, KEGG pathways and Ingenuity Pathway analysis to reveal the molecular functions and gene networks associated with collagen VI defects. The most significantly regulated pathways were those involved in muscle regeneration, extracellular matrix remodelling and inflammation. We characterised the immune response in UCMD biopsies as being mainly mediated via M2 macrophages and the complement pathway indicating that anti-inflammatory treatment may be beneficial to UCMD as for other dystrophies. We studied the immunolocalisation of ECM components and found that biglycan, a collagen VI interacting proteoglycan, was reduced in the basal lamina of UCMD patients. We propose that biglycan reduction is secondary to collagen VI loss and that it may be contributing towards UCMD pathophysiology. Consequently, strategies aimed at over-expressing biglycan and restore the link between the muscle cell surface and the extracellular matrix should be considered.
Collapse
|
19
|
Katsetos CD, Koutzaki S, Melvin JJ. Mitochondrial dysfunction in neuromuscular disorders. Semin Pediatr Neurol 2013; 20:202-15. [PMID: 24331362 DOI: 10.1016/j.spen.2013.10.010] [Citation(s) in RCA: 58] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
This review deciphers aspects of mitochondrial (mt) dysfunction among nosologically, pathologically, and genetically diverse diseases of the skeletal muscle, lower motor neuron, and peripheral nerve, which fall outside the traditional realm of mt cytopathies. Special emphasis is given to well-characterized mt abnormalities in collagen VI myopathies (Ullrich congenital muscular dystrophy and Bethlem myopathy), megaconial congenital muscular dystrophy, limb-girdle muscular dystrophy type 2 (calpainopathy), centronuclear myopathies, core myopathies, inflammatory myopathies, spinal muscular atrophy, Charcot-Marie-Tooth neuropathy type 2, and drug-induced peripheral neuropathies. Among inflammatory myopathies, mt abnormalities are more prominent in inclusion body myositis and a subset of polymyositis with mt pathology, both of which are refractory to corticosteroid treatment. Awareness is raised about instances of phenotypic mimicry between cases harboring primary mtDNA depletion, in the context of mtDNA depletion syndrome, and established neuromuscular disorders such as spinal muscular atrophy. A substantial body of experimental work, derived from animal models, attests to a major role of mitochondria (mt) in the early process of muscle degeneration. Common mechanisms of mt-related cell injury include dysregulation of the mt permeability transition pore opening and defective autophagy. The therapeutic use of mt permeability transition pore modifiers holds promise in various neuromuscular disorders, including muscular dystrophies.
Collapse
Affiliation(s)
- Christos D Katsetos
- Department of Pediatrics, Drexel University College of Medicine, St. Christopher's Hospital for Children, Philadelphia, PA; Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia, PA; Department of Neurology, Drexel University College of Medicine, Philadelphia, PA.
| | - Sirma Koutzaki
- Department of Pathology and Laboratory Medicine, Drexel University College of Medicine, Philadelphia, PA
| | - Joseph J Melvin
- Department of Pediatrics, Drexel University College of Medicine, St. Christopher's Hospital for Children, Philadelphia, PA; Department of Neurology, Drexel University College of Medicine, Philadelphia, PA
| |
Collapse
|
20
|
Yazdi PG, Su H, Ghimbovschi S, Fan W, Coskun PE, Nalbandian A, Knoblach S, Resnick JL, Hoffman E, Wallace DC, Kimonis VE. Differential gene expression reveals mitochondrial dysfunction in an imprinting center deletion mouse model of Prader-Willi syndrome. Clin Transl Sci 2013; 6:347-55. [PMID: 24127921 DOI: 10.1111/cts.12083] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
Prader-Willi syndrome (PWS) is a genetic disorder caused by deficiency of imprinted gene expression from the paternal chromosome 15q11-15q13 and clinically characterized by neonatal hypotonia, short stature, cognitive impairment, hypogonadism, hyperphagia, morbid obesity, and diabetes. Previous clinical studies suggest that a defect in energy metabolism may be involved in the pathogenesis of PWS. We focused our attention on the genes associated with energy metabolism and found that there were 95 and 66 mitochondrial genes differentially expressed in PWS muscle and brain, respectively. Assessment of enzyme activities of mitochondrial oxidative phosphorylation complexes in the brain, heart, liver, and muscle were assessed. We found the enzyme activities of the cardiac mitochondrial complexes II+III were up-regulated in the PWS imprinting center deletion mice compared to the wild-type littermates. These studies suggest that differential gene expression, especially of the mitochondrial genes may contribute to the pathophysiology of PWS.
Collapse
Affiliation(s)
- Puya G Yazdi
- Division of Genetics and Metabolism, Department of Pediatrics, University of California, Irvine, California, USA
| | | | | | | | | | | | | | | | | | | | | |
Collapse
|
21
|
Bernardi P, Bonaldo P. Mitochondrial dysfunction and defective autophagy in the pathogenesis of collagen VI muscular dystrophies. Cold Spring Harb Perspect Biol 2013; 5:a011387. [PMID: 23580791 DOI: 10.1101/cshperspect.a011387] [Citation(s) in RCA: 55] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
Ullrich Congenital Muscular Dystrophy (UCMD), Bethlem Myopathy (BM), and Congenital Myosclerosis are diseases caused by mutations in the genes encoding the extracellular matrix protein collagen VI. A dystrophic mouse model, where collagen VI synthesis was prevented by targeted inactivation of the Col6a1 gene, allowed the investigation of pathogenesis, which revealed the existence of a Ca(2+)-mediated dysfunction of mitochondria and sarcoplasmic reticulum, and of defective autophagy. Key events are dysregulation of the mitochondrial permeability transition pore, an inner membrane high-conductance channel that for prolonged open times causes mitochondrial dysfunction, and inadequate removal of defective mitochondria, which amplifies the damage. Consistently, the Col6a1(-/-) myopathic mice could be cured through inhibition of cyclophilin D, a matrix protein that sensitizes the pore to opening, and through stimulation of autophagy. Similar defects contribute to disease pathogenesis in patients irrespective of the genetic lesion causing the collagen VI defect. These studies indicate that permeability transition pore opening and defective autophagy represent key elements for skeletal muscle fiber death, and provide a rationale for the use of cyclosporin A and its nonimmunosuppressive derivatives in patients affected by collagen VI myopathies, a strategy that holds great promise for treatment.
Collapse
Affiliation(s)
- Paolo Bernardi
- Department of Biomedical Sciences, University of Padova, I-35121 Padova, Italy.
| | | |
Collapse
|
22
|
Pellegrini C, Zulian A, Gualandi F, Manzati E, Merlini L, Michelini ME, Benassi L, Marmiroli S, Ferlini A, Sabatelli P, Bernardi P, Maraldi NM. Melanocytes--a novel tool to study mitochondrial dysfunction in Duchenne muscular dystrophy. J Cell Physiol 2013; 228:1323-31. [PMID: 23169061 PMCID: PMC3601437 DOI: 10.1002/jcp.24290] [Citation(s) in RCA: 27] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/07/2012] [Accepted: 11/09/2012] [Indexed: 12/19/2022]
Abstract
Dystrophin is a subsarcolemmal protein that, by linking the actin cytoskeleton to the extracellular matrix via dystroglycans, is critical for the integrity of muscle fibers. Here, we report that epidermal melanocytes, obtained from conventional skin biopsy, express dystrophin with a restricted localization to the plasma membrane facing the dermal–epidermal junction. In addition the full-length muscle isoform mDp427 was clearly detectable in melanocyte cultures as assessed by immunohistochemistry, RNA, and Western blot analysis. Melanocytes of Duchenne muscular dystrophy (DMD) patients did not express dystrophin, and the ultrastructural analysis revealed typical mitochondrial alterations similar to those occurring in myoblasts from the same patients. Mitochondria of melanocytes from DMD patients readily accumulated tetramethylrhodamine methyl ester, indicating that they are energized irrespective of the presence of dystrophin but, at variance from mitochondria of control donors, depolarized upon the addition of oligomycin, suggesting that they are affected by a latent dysfunction unmasked by inhibition of the ATP synthase. Pure melanocyte cultures can be readily obtained by conventional skin biopsies and may be a feasible and reliable tool alternative to muscle biopsy for functional studies in dystrophinopathies. The mitochondrial dysfunction occurring in DMD melanocytes could represent a promising cellular biomarker for monitoring dystrophinopathies also in response to pharmacological treatments. J. Cell. Physiol. 228: 1323–1331, 2013. © 2012 Wiley Periodicals, Inc.
Collapse
|
23
|
Sabatelli P, Palma E, Angelin A, Squarzoni S, Urciuolo A, Pellegrini C, Tiepolo T, Bonaldo P, Gualandi F, Merlini L, Bernardi P, Maraldi NM. Critical evaluation of the use of cell cultures for inclusion in clinical trials of patients affected by collagen VI myopathies. J Cell Physiol 2012; 227:2927-35. [PMID: 21953374 PMCID: PMC3415679 DOI: 10.1002/jcp.23039] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Collagen VI myopathies (Ullrich congenital muscular dystrophy (UCMD), Bethlem myopathy (BM), and myosclerosis myopathy) share a common pathogenesis, that is, mitochondrial dysfunction due to deregulation of the permeability transition pore (PTP). This effect was first identified in the Col6a1(-/-) mouse model and then in muscle cell cultures from UCMD and BM patients; the normalizing effect of cyclosporin A (CsA) confirmed the pathogenic role of PTP opening. In order to determine whether mitochondrial performance can be used as a criterion for inclusion in clinical trials and as an outcome measure of the patient response to therapy, it is mandatory to establish whether mitochondrial dysfunction is conserved in primary cell cultures from UCMD and BM patients. In this study we report evidence that mitochondrial dysfunction and the consequent increase of apoptotic rate can be detected not only, as previously reported, in muscle, but also in fibroblast cell cultures established from muscle biopsies of collagen VI-related myopathic patients. However, the mitochondrial phenotype is no longer maintained after nine passages in culture. These data demonstrate that the dire consequences of mitochondrial dysfunction are not limited to myogenic cells, and that this parameter can be used as a suitable diagnostic criterion, provided that the cell culture conditions are carefully established.
Collapse
Affiliation(s)
- P Sabatelli
- CNR-National Research Council of Italy, Institute of Molecular Genetics c/o IOR, Bologna, Italy
| | | | | | | | | | | | | | | | | | | | | | | |
Collapse
|
24
|
Cyclosporine A in Ullrich congenital muscular dystrophy: long-term results. OXIDATIVE MEDICINE AND CELLULAR LONGEVITY 2011; 2011:139194. [PMID: 22028947 PMCID: PMC3199070 DOI: 10.1155/2011/139194] [Citation(s) in RCA: 42] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 05/19/2011] [Revised: 08/09/2011] [Accepted: 08/11/2011] [Indexed: 11/18/2022]
Abstract
Six individuals with Ullrich congenital muscular dystrophy (UCMD) and mutations in the genes-encoding collagen VI, aging 5–9, received 3–5 mg/kg of cyclosporine A (CsA) daily for 1 to 3.2 years. The primary outcome measure was the muscle strength evaluated with a myometer and expressed as megalimbs. The megalimbs score showed significant improvement (P = 0.01) in 5 of the 6 patients. Motor function did not change. Respiratory function deteriorated in all. CsA treatment corrected mitochondrial dysfunction, increased muscle regeneration, and decreased the number of apoptotic nuclei. Results from this study demonstrate that long-term treatment with CsA ameliorates performance in the limbs, but not in the respiratory muscles of UCMD patients, and that it is well tolerated. These results suggest considering a trial of CsA or nonimmunosuppressive cyclosporins, that retains the PTP-desensitizing properties of CsA, as early as possible in UCMD patients when diaphragm is less compromised.
Collapse
|
25
|
Abstract
The collagen VI-related myopathy known as Ullrich congenital muscular dystrophy is an early-onset disease that combines substantial muscle weakness with striking joint laxity and progressive contractures. Patients might learn to walk in early childhood; however, this ability is subsequently lost, concomitant with the development of frequent nocturnal respiratory failure. Patients with intermediate phenotypes of collagen VI-related myopathy display a lesser degree of weakness and a longer period of ambulation than do individuals with Ullrich congenital muscular dystrophy, and the spectrum of disease finally encompasses mild Bethlem myopathy, in which ambulation persists into adulthood. Dominant and recessive autosomal mutations in the three major collagen VI genes-COL6A1, COL6A2, and COL6A3-can underlie this entire clinical spectrum, and result in deficient or dysfunctional microfibrillar collagen VI in the extracellular matrix of muscle and other connective tissues, such as skin and tendons. The potential effects on muscle include progressive dystrophic changes, fibrosis and evidence for increased apoptosis, which potentially open avenues for pharmacological intervention. Optimized respiratory management, including noninvasive nocturnal ventilation together with careful orthopedic management, are the current mainstays of treatment and have already led to a considerable improvement in life expectancy for children with Ullrich congenital muscular dystrophy.
Collapse
|
26
|
Rasola A, Bernardi P. Mitochondrial permeability transition in Ca(2+)-dependent apoptosis and necrosis. Cell Calcium 2011; 50:222-33. [PMID: 21601280 DOI: 10.1016/j.ceca.2011.04.007] [Citation(s) in RCA: 386] [Impact Index Per Article: 29.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2011] [Revised: 04/22/2011] [Accepted: 04/28/2011] [Indexed: 12/25/2022]
Abstract
A variety of stimuli utilize an increase of cytosolic free Ca(2+) concentration as a second messenger to transmit signals, through Ca(2+) release from the endoplasmic reticulum or opening of plasma membrane Ca(2+) channels. Mitochondria contribute to the tight spatiotemporal control of this process by accumulating Ca(2+), thus shaping the return of cytosolic Ca(2+) to resting levels. The rise of mitochondrial matrix free Ca(2+) concentration stimulates oxidative metabolism; yet, in the presence of a variety of sensitizing factors of pathophysiological relevance, the matrix Ca(2+) increase can also lead to opening of the permeability transition pore (PTP), a high conductance inner membrane channel. While transient openings may serve the purpose of providing a fast Ca(2+) release mechanism, persistent PTP opening is followed by deregulated release of matrix Ca(2+), termination of oxidative phosphorylation, matrix swelling with inner membrane unfolding and eventually outer membrane rupture with release of apoptogenic proteins and cell death. Thus, a rise in mitochondrial Ca(2+) can convey both apoptotic and necrotic death signals by inducing opening of the PTP. Understanding the signalling networks that govern changes in mitochondrial free Ca(2+) concentration, their interplay with Ca(2+) signalling in other subcellular compartments, and regulation of PTP has important implications in the fine comprehension of the main biological routines of the cell and in disease pathogenesis.
Collapse
Affiliation(s)
- Andrea Rasola
- Department of Biomedical Sciences and CNR Institute of Neuroscience, University of Padova, Italy.
| | | |
Collapse
|
27
|
Reed UC. Congenital muscular dystrophy. Part II: a review of pathogenesis and therapeutic perspectives. ARQUIVOS DE NEURO-PSIQUIATRIA 2010; 67:343-62. [PMID: 19547838 DOI: 10.1590/s0004-282x2009000200035] [Citation(s) in RCA: 38] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/31/2008] [Accepted: 03/14/2009] [Indexed: 11/22/2022]
Abstract
The congenital muscular dystrophies (CMDs) are a group of genetically and clinically heterogeneous hereditary myopathies with preferentially autosomal recessive inheritance, that are characterized by congenital hypotonia, delayed motor development and early onset of progressive muscle weakness associated with dystrophic pattern on muscle biopsy. The clinical course is broadly variable and can comprise the involvement of the brain and eyes. From 1994, a great development in the knowledge of the molecular basis has occurred and the classification of CMDs has to be continuously up dated. In the last number of this journal, we presented the main clinical and diagnostic data concerning the different subtypes of CMD. In this second part of the review, we analyse the main reports from the literature concerning the pathogenesis and the therapeutic perspectives of the most common subtypes of CMD: MDC1A with merosin deficiency, collagen VI related CMDs (Ullrich and Bethlem), CMDs with abnormal glycosylation of alpha-dystroglycan (Fukuyama CMD, Muscle-eye-brain disease, Walker Warburg syndrome, MDC1C, MDC1D), and rigid spine syndrome, another much rare subtype of CMDs not related with the dystrophin/glycoproteins/extracellular matrix complex.
Collapse
|
28
|
Palma E, Tiepolo T, Angelin A, Sabatelli P, Maraldi NM, Basso E, Forte MA, Bernardi P, Bonaldo P. Genetic ablation of cyclophilin D rescues mitochondrial defects and prevents muscle apoptosis in collagen VI myopathic mice. Hum Mol Genet 2009; 18:2024-31. [PMID: 19293339 DOI: 10.1093/hmg/ddp126] [Citation(s) in RCA: 94] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/16/2023] Open
Abstract
Ullrich congenital muscular dystrophy (UCMD) and Bethlem myopathy are inherited muscle disorders caused by mutations of genes encoding the extracellular matrix protein collagen VI (ColVI). Mice lacking ColVI (Col6a1(-/-)) display a myopathic phenotype associated with ultrastructural alterations of mitochondria and sarcoplasmic reticulum, mitochondrial dysfunction with abnormal opening of the permeability transition pore (PTP) and increased apoptosis of muscle fibers. Treatment with cyclosporin (Cs) A, a drug that desensitizes the PTP by binding to cyclophilin (Cyp)-D, was shown to rescue myofiber alterations in Col6a1(-/-) mice and in UCMD patients, suggesting a correlation between PTP opening and pathogenesis of ColVI muscular dystrophies. Here, we show that inactivation of the gene encoding for Cyp-D rescues the disease phenotype of ColVI deficiency. In the absence of Cyp-D, Col6a1(-/-) mice show negligible myofiber degeneration, rescue from mitochondrial dysfunction and ultrastructural defects, and normalized incidence of apoptosis. These findings (i) demonstrate that lack of Cyp-D is equivalent to its inhibition with CsA at curing the mouse dystrophic phenotype; (ii) establish a cause-effect relationship between Cyp-D-dependent PTP regulation and pathogenesis of the ColVI muscular dystrophy and (iii) validate Cyp-D and the PTP as pharmacological targets for the therapy of human ColVI myopathies.
Collapse
Affiliation(s)
- Elena Palma
- Department of Biomedical Sciences, University of Padova, 35121 Padova, Italy
| | | | | | | | | | | | | | | | | |
Collapse
|
29
|
Bernardi P, Bonaldo P, Maraldi NM, Merlini L, Sabatelli P. On the pathogenesis of collagen VI muscular dystrophies--Comment on article of Hicks et al. Brain 2009; 132:e121; author reply e122. [DOI: 10.1093/brain/awp021] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/12/2022] Open
|
30
|
Nowikovsky K, Schweyen RJ, Bernardi P. Pathophysiology of mitochondrial volume homeostasis: potassium transport and permeability transition. BIOCHIMICA ET BIOPHYSICA ACTA-BIOENERGETICS 2008; 1787:345-50. [PMID: 19007745 DOI: 10.1016/j.bbabio.2008.10.006] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/30/2008] [Revised: 10/11/2008] [Accepted: 10/15/2008] [Indexed: 10/21/2022]
Abstract
Regulation of mitochondrial volume is a key issue in cellular pathophysiology. Mitochondrial volume and shape changes can occur following regulated fission-fusion events, which are modulated by a complex network of cytosolic and mitochondrial proteins; and through regulation of ion transport across the inner membrane. In this review we will cover mitochondrial volume homeostasis that depends on (i) monovalent cation transport across the inner membrane, a regulated process that couples electrophoretic K(+) influx on K(+) channels to K(+) extrusion through the K(+)-H(+) exchanger; (ii) the permeability transition, a loss of inner membrane permeability that may be instrumental in triggering cell death. Specific emphasis will be placed on molecular advances on the nature of the transport protein(s) involved, and/or on diseases that depend on mitochondrial volume dysregulation.
Collapse
|