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Lobato AG, Ortiz-Vega N, Canic T, Tao X, Bucan N, Ruan K, Rebelo AP, Schule R, Zuchner S, Syed S, Zhai RG. Loss of Fic causes progressive neurodegeneration in a Drosophila model of hereditary spastic paraplegia. Biochim Biophys Acta Mol Basis Dis 2024; 1870:167348. [PMID: 38986817 DOI: 10.1016/j.bbadis.2024.167348] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2024] [Revised: 07/03/2024] [Accepted: 07/03/2024] [Indexed: 07/12/2024]
Abstract
Hereditary Spastic Paraplegia (HSP) is a group of rare inherited disorders characterized by progressive weakness and spasticity of the legs. Recent newly discovered biallelic variants in the gene FICD were found in patients with a highly similar phenotype to early onset HSP. FICD encodes filamentation induced by cAMP domain protein. FICD is involved in the AMPylation and deAMPylation protein modifications of the endoplasmic reticulum (ER) chaperone BIP, a major constituent of the ER that regulates the unfolded protein response. Although several biochemical properties of FICD have been characterized, the neurological function of FICD and the pathological mechanism underlying HSP are unknown. We established a Drosophila model to gain mechanistic understanding of the function of FICD in HSP pathogenesis, and specifically the role of BIP in neuromuscular physiology. Our studies on Drosophila Fic null mutants uncovered that loss of Fic resulted in locomotor impairment and reduced levels of BIP in the motor neuron circuitry, as well as increased reactive oxygen species (ROS) in the ventral nerve cord of Fic null mutants. Finally, feeding Drosophila Fic null mutants with chemical chaperones PBA or TUDCA, or treatment of patient fibroblasts with PBA, reduced the ROS accumulation. The neuronal phenotypes of Fic null mutants recapitulate several clinical features of HSP patients and further reveal cellular patho-mechanisms. By modeling FICD in Drosophila, we provide potential targets for intervention for HSP, and advance fundamental biology that is important for understanding related rare and common neuromuscular diseases.
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Affiliation(s)
- Amanda G Lobato
- Department of Neurology, University of Chicago, Chicago, IL, USA; Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA; Graduate Program in Human Genetics and Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Natalie Ortiz-Vega
- Department of Neurology, University of Chicago, Chicago, IL, USA; Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA; Graduate Program in Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, FL, USA
| | - Tijana Canic
- Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA; Graduate Program in Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, FL, USA
| | - Xianzun Tao
- Department of Neurology, University of Chicago, Chicago, IL, USA; Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Nika Bucan
- Undergraduate Program in Neuroscience, University of Miami, Coral Gables, FL, USA
| | - Kai Ruan
- Department of Neurology, University of Chicago, Chicago, IL, USA; Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Adriana P Rebelo
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Rebecca Schule
- Hertie Institute for Clinical Brain Research (HIH), Center of Neurology, University of Tübingen, Tübingen, Germany; German Center for Neurodegenerative Diseases (DZNE), University of Tübingen, Tübingen, Germany
| | - Stephan Zuchner
- Dr. John T. Macdonald Foundation Department of Human Genetics and John P. Hussman Institute for Human Genomics, University of Miami Miller School of Medicine, Miami, FL, USA
| | - Sheyum Syed
- Department of Physics, University of Miami, Coral Gables, FL, USA
| | - R Grace Zhai
- Department of Neurology, University of Chicago, Chicago, IL, USA; Department of Molecular and Cellular Pharmacology, University of Miami Miller School of Medicine, Miami, FL, USA.
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Damiani D, Baggiani M, Della Vecchia S, Naef V, Santorelli FM. Pluripotent Stem Cells as a Preclinical Cellular Model for Studying Hereditary Spastic Paraplegias. Int J Mol Sci 2024; 25:2615. [PMID: 38473862 DOI: 10.3390/ijms25052615] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/08/2024] [Revised: 02/12/2024] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
Hereditary spastic paraplegias (HSPs) comprise a family of degenerative diseases mostly hitting descending axons of corticospinal neurons. Depending on the gene and mutation involved, the disease could present as a pure form with limb spasticity, or a complex form associated with cerebellar and/or cortical signs such as ataxia, dysarthria, epilepsy, and intellectual disability. The progressive nature of HSPs invariably leads patients to require walking canes or wheelchairs over time. Despite several attempts to ameliorate the life quality of patients that have been tested, current therapeutical approaches are just symptomatic, as no cure is available. Progress in research in the last two decades has identified a vast number of genes involved in HSP etiology, using cellular and animal models generated on purpose. Although unanimously considered invaluable tools for basic research, those systems are rarely predictive for the establishment of a therapeutic approach. The advent of induced pluripotent stem (iPS) cells allowed instead the direct study of morphological and molecular properties of the patient's affected neurons generated upon in vitro differentiation. In this review, we revisited all the present literature recently published regarding the use of iPS cells to differentiate HSP patient-specific neurons. Most studies have defined patient-derived neurons as a reliable model to faithfully mimic HSP in vitro, discovering original findings through immunological and -omics approaches, and providing a platform to screen novel or repurposed drugs. Thereby, one of the biggest hopes of current HSP research regards the use of patient-derived iPS cells to expand basic knowledge on the disease, while simultaneously establishing new therapeutic treatments for both generalized and personalized approaches in daily medical practice.
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Affiliation(s)
- Devid Damiani
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris, Via dei Giacinti 2, 56128 Pisa, Italy
| | - Matteo Baggiani
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris, Via dei Giacinti 2, 56128 Pisa, Italy
| | - Stefania Della Vecchia
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris, Via dei Giacinti 2, 56128 Pisa, Italy
- Department of Neurosciences, Psychology, Drug Research and Child Health (NEUROFARBA), University of Florence, Viale Pieraccini, 6, 50139 Florence, Italy
| | - Valentina Naef
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris, Via dei Giacinti 2, 56128 Pisa, Italy
| | - Filippo Maria Santorelli
- Molecular Medicine for Neurodegenerative and Neuromuscular Diseases Unit, IRCCS Fondazione Stella Maris, Via dei Giacinti 2, 56128 Pisa, Italy
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Gao X, Feng B, Du C, Hou C, Jin S, Tang D, Zhu J, Lv Y. Expression dynamics indicate the involvement of SPG7 in the reproduction and spermiogenesis of Phascolosoma esculenta. Gene 2024; 895:148028. [PMID: 38007160 DOI: 10.1016/j.gene.2023.148028] [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: 06/28/2023] [Revised: 11/17/2023] [Accepted: 11/22/2023] [Indexed: 11/27/2023]
Abstract
Spastic paraplegia 7 (SPG7) is an m-AAA protease subunit involved in mitochondrial morphology and physiology. However, its function in animal reproduction is yet to be evaluated. In this study, its molecular features, subcellular localization, and expression dynamics were investigated to analyze its potential function in the reproduction of male Phascolosoma esculenta, an economically important marine species in China. The full-length cDNA of P. esculenta spg7 (Pe-spg7) measures 3053 bp and encodes an 853-amino acid protein (Pe-SPG7). Pe-SPG7 includes two transmembrane domains, an AAA domain and a proteolytic domain. Amino acid sequence alignment revealed that SPG7 was conserved during evolution. The mRNA and protein expression of spg7 indicated its involvement in reproduction. Its expression was the highest in coelomic fluid, where spermatids develop, and it was significantly higher in the breeding stage than in the nonbreeding stage. SPG7 was mainly found in the mitochondria of spermatids in the coelomic fluid, indicating that it functions in this organelle in spermatids. Immunofluorescence experiments showed that SPG7 was expressed and colocalized in the mitochondria during spermiogenesis, suggesting its involvement in P. esculenta spermiogenesis. Therefore, SPG7 may participate in spermiogenesis by functioning in the mitochondria and regulate the reproduction of male P. esculenta. This study provided insights into the function of SPG7 in animal reproduction and P. esculenta gametogenesis.
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Affiliation(s)
- Xinming Gao
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education and Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China; College of Ecology, Lishui University, Lishui, Zhejiang, 323000, People's Republic of China
| | - Binbin Feng
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education and Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Chen Du
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education and Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Congcong Hou
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education and Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Shan Jin
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education and Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China
| | - Daojun Tang
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education and Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China.
| | - Junquan Zhu
- Key Laboratory of Applied Marine Biotechnology by the Ministry of Education and Key Laboratory of Marine Biotechnology of Zhejiang Province, School of Marine Sciences, Ningbo University, Ningbo, Zhejiang 315211, People's Republic of China.
| | - Yaoping Lv
- College of Ecology, Lishui University, Lishui, Zhejiang, 323000, People's Republic of China.
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Guangming G, Mei C, Qinfeng Y, Xiang G, Chenchen Z, Qingyuan S, Wei X, Junhua G. Neurexin and neuroligins jointly regulate synaptic degeneration at the Drosophila neuromuscular junction based on TEM studies. Front Cell Neurosci 2023; 17:1257347. [PMID: 38026694 PMCID: PMC10646337 DOI: 10.3389/fncel.2023.1257347] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/12/2023] [Accepted: 09/12/2023] [Indexed: 12/01/2023] Open
Abstract
The Drosophila larval neuromuscular junction (NMJ) is a well-known model system and is often used to study synapse development. Here, we show synaptic degeneration at NMJ boutons, primarily based on transmission electron microscopy (TEM) studies. When degeneration starts, the subsynaptic reticulum (SSR) swells, retracts and folds inward, and the residual SSR then degenerates into a disordered, thin or linear membrane. The axon terminal begins to degenerate from the central region, and the T-bar detaches from the presynaptic membrane with clustered synaptic vesicles to accelerate large-scale degeneration. There are two degeneration modes for clear synaptic vesicles. In the first mode, synaptic vesicles without actin filaments degenerate on the membrane with ultrafine spots and collapse and disperse to form an irregular profile with dark ultrafine particles. In the second mode, clear synaptic vesicles with actin filaments degenerate into dense synaptic vesicles, form irregular dark clumps without a membrane, and collapse and disperse to form an irregular profile with dark ultrafine particles. Last, all residual membranes in NMJ boutons degenerate into a linear shape, and all the residual elements in axon terminals degenerate and eventually form a cluster of dark ultrafine particles. Swelling and retraction of the SSR occurs prior to degradation of the axon terminal, which degenerates faster and with more intensity than the SSR. NMJ bouton degeneration occurs under normal physiological conditions but is accelerated in Drosophila neurexin (dnrx) dnrx273, Drosophila neuroligin (dnlg) dnlg1 and dnlg4 mutants and dnrx83;dnlg3 and dnlg2;dnlg3 double mutants, which suggests that both neurexin and neuroligins play a vital role in preventing synaptic degeneration.
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Affiliation(s)
- Gan Guangming
- School of Medicine, Southeast University, Nanjing, Jiangsu, China
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu, China
| | - Chen Mei
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu, China
| | - Yu Qinfeng
- School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Gao Xiang
- School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Zhang Chenchen
- School of Medicine, Southeast University, Nanjing, Jiangsu, China
| | - Sheng Qingyuan
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu, China
| | - Xie Wei
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu, China
- The Collaborative Innovation Center for Brain Science, Southeast University, Nanjing, Jiangsu, China
| | - Geng Junhua
- School of Life Science and Technology, The Key Laboratory of Developmental Genes and Human Disease, Southeast University, Nanjing, Jiangsu, China
- Shenzhen Research Institute of Southeast University, Shenzhen, Guangdong, China
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Martinello C, Panza E, Orlacchio A. Hereditary spastic paraplegias proteome: common pathways and pathogenetic mechanisms. Expert Rev Proteomics 2023; 20:171-188. [PMID: 37788157 DOI: 10.1080/14789450.2023.2260952] [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: 06/12/2023] [Accepted: 08/31/2023] [Indexed: 10/05/2023]
Abstract
INTRODUCTION Hereditary spastic paraplegias (HSPs) are a group of inherited neurodegenerative disorders characterized by progressive spasticity and weakness of the lower limbs. These conditions are caused by lesions in the neuronal pyramidal tract and exhibit clinical and genetic variability. Ongoing research focuses on understanding the underlying mechanisms of HSP onset, which ultimately lead to neuronal degeneration. Key molecular mechanisms involved include axonal transport, cytoskeleton dynamics, myelination abnormalities, membrane trafficking, organelle morphogenesis, ER homeostasis, mitochondrial dysfunction, and autophagy deregulation. AREAS COVERED This review aims to provide an overview of the shared pathogenetic mechanisms in various forms of HSPs. By examining disease-causing gene products and their associated functional pathways, this understanding could lead to the discovery of new therapeutic targets and the development of treatments to modify the progression of the disease. EXPERT OPINION Investigating gene functionality is crucial for identifying shared pathogenetic pathways underlying different HSP subtypes. Categorizing protein function and identifying pathways aids in finding biomarkers, predicting early onset, and guiding treatment for a better quality of life. Targeting shared mechanisms enables efficient and cost-effective therapies. Prospects involve identifying new disease-causing genes, refining molecular processes, and implementing findings in diagnosis, key for advancing HSP understanding and developing effective treatments.
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Affiliation(s)
- Chiara Martinello
- Dipartimento di Scienze Mediche e Chirurgiche, Università di Bologna, Bologna, Italy
| | - Emanuele Panza
- Dipartimento di Scienze Mediche e Chirurgiche, Università di Bologna, Bologna, Italy
- Unità di Genetica Medica, Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Azienda Ospedaliero-Universitaria di Bologna, Bologna, Italy
| | - Antonio Orlacchio
- Laboratorio di Neurogenetica, Centro Europeo di Ricerca sul Cervello (CERC), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy
- Dipartimento di Medicina e Chirurgia, Università di Perugia, Perugia, Italy
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6
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Barone C, Qi X. Altered Metabolism in Motor Neuron Diseases: Mechanism and Potential Therapeutic Target. Cells 2023; 12:1536. [PMID: 37296656 PMCID: PMC10252517 DOI: 10.3390/cells12111536] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2023] [Revised: 05/21/2023] [Accepted: 05/31/2023] [Indexed: 06/12/2023] Open
Abstract
Motor Neuron Diseases (MND) are neurological disorders characterized by a loss of varying motor neurons resulting in decreased physical capabilities. Current research is focused on hindering disease progression by determining causes of motor neuron death. Metabolic malfunction has been proposed as a promising topic when targeting motor neuron loss. Alterations in metabolism have also been noted at the neuromuscular junction (NMJ) and skeletal muscle tissue, emphasizing the importance of a cohesive system. Finding metabolism changes consistent throughout both neurons and skeletal muscle tissue could pose as a target for therapeutic intervention. This review will focus on metabolic deficits reported in MNDs and propose potential therapeutic targets for future intervention.
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Affiliation(s)
| | - Xin Qi
- Department of Physiology and Biophysics, School of Medicine Case Western Reserve University, Cleveland, OH 44106-4970, USA;
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Carraro M, Bernardi P. The mitochondrial permeability transition pore in Ca 2+ homeostasis. Cell Calcium 2023; 111:102719. [PMID: 36963206 DOI: 10.1016/j.ceca.2023.102719] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 03/17/2023] [Accepted: 03/18/2023] [Indexed: 03/26/2023]
Abstract
The mitochondrial Permeability Transition Pore (PTP) can be defined as a Ca2+ activated mega-channel involved in mitochondrial damage and cell death, making its inhibition a hallmark for therapeutic purposes in many PTP-related paradigms. Although long-lasting PTP openings have been widely studied, the physiological implications of transient openings (also called "flickering" behavior) are still poorly understood. The flickering activity was suggested to play a role in the regulation of Ca2+ and ROS homeostasis, and yet this hypothesis did not reach general consensus. This state of affairs might arise from the lack of unquestionable experimental evidence, due to limitations of the available techniques for capturing transient PTP activity and to a still partial understanding of its molecular identity. In this review we will focus on possible implications of the PTP in physiology, in particular its role as a Ca2+ release pathway, discussing the consequences of its forced inhibition. We will also consider the recent hypothesis of the existence of more permeability pathways and their potential involvement in mitochondrial physiology.
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Affiliation(s)
- Michela Carraro
- Department of Biomedical Sciences, University of Padova and CNR Neuroscience Institute, Via Ugo Bassi 58/B, I-35131 Padova, Italy.
| | - Paolo Bernardi
- Department of Biomedical Sciences, University of Padova and CNR Neuroscience Institute, Via Ugo Bassi 58/B, I-35131 Padova, Italy
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Tian X, Lou S, Shi R. From mitochondria to sarcopenia: role of 17β-estradiol and testosterone. Front Endocrinol (Lausanne) 2023; 14:1156583. [PMID: 37152937 PMCID: PMC10157222 DOI: 10.3389/fendo.2023.1156583] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/01/2023] [Accepted: 04/03/2023] [Indexed: 05/09/2023] Open
Abstract
Sarcopenia, characterized by a loss of muscle mass and strength with aging, is prevalent in older adults. Although the exact mechanisms underlying sarcopenia are not fully understood, evidence suggests that the loss of mitochondrial integrity in skeletal myocytes has emerged as a pivotal contributor to the complex etiology of sarcopenia. Mitochondria are the primary source of ATP production and are also involved in generating reactive oxygen species (ROS), regulating ion signals, and initiating apoptosis signals in muscle cells. The accumulation of damaged mitochondria due to age-related impairments in any of the mitochondrial quality control (MQC) processes, such as proteostasis, biogenesis, dynamics, and mitophagy, can contribute to the decline in muscle mass and strength associated with aging. Interestingly, a decrease in sex hormones (e.g., 17β-estradiol and testosterone), which occurs with aging, has also been linked to sarcopenia. Indeed, 17β-estradiol and testosterone targeted mitochondria and exhibited activities in regulating mitochondrial functions. Here, we overview the current literature on the key mechanisms by which mitochondrial dysfunction contribute to the development and progression of sarcopenia and the potential modulatory effects of 17β-estradiol and testosterone on mitochondrial function in this context. The advance in its understanding will facilitate the development of potential therapeutic agents to mitigate and manage sarcopenia.
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Pareek G. AAA+ proteases: the first line of defense against mitochondrial damage. PeerJ 2022; 10:e14350. [PMID: 36389399 PMCID: PMC9648348 DOI: 10.7717/peerj.14350] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Accepted: 10/16/2022] [Indexed: 11/09/2022] Open
Abstract
Mitochondria play essential cellular roles in Adenosine triphosphate (ATP) synthesis, calcium homeostasis, and metabolism, but these vital processes have potentially deadly side effects. The production of the reactive oxygen species (ROS) and the aggregation of misfolded mitochondrial proteins can lead to severe mitochondrial damage and even cell death. The accumulation of mitochondrial damage is strongly implicated in aging and several incurable diseases, including neurodegenerative disorders and cancer. To oppose this, metazoans utilize a variety of quality control strategies, including the degradation of the damaged mitochondrial proteins by the mitochondrial-resident proteases of the ATPase Associated with the diverse cellular Activities (AAA+) family. This mini-review focuses on the quality control mediated by the mitochondrial-resident proteases of the AAA+ family used to combat the accumulation of damaged mitochondria and on how the failure of this mitochondrial quality control contributes to diseases.
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10
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Panza E, Meyyazhagan A, Orlacchio A. Hereditary spastic paraplegia: Genetic heterogeneity and common pathways. Exp Neurol 2022; 357:114203. [PMID: 35970204 DOI: 10.1016/j.expneurol.2022.114203] [Citation(s) in RCA: 15] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/13/2022] [Revised: 07/11/2022] [Accepted: 08/09/2022] [Indexed: 02/07/2023]
Abstract
Hereditary Spastic Paraplegias (HSPs) are a heterogeneous group of disease, mainly characterized by progressive spasticity and weakness of the lower limbs resulting from distal degeneration of corticospinal tract axons. Although HSPs represent rare or ultra-rare conditions, with reported cases of mutated genes found in single families, overall, with 87 forms described, they are an important health and economic problem for society and patients. In fact, they are chronic and life-hindering conditions, still lacking a specific therapy. Notwithstanding the number of forms described, and 73 causative genes identified, overall, the molecular diagnostic rate varies among 29% to 61.8%, based on recent published analysis, suggesting that more genes are involved in HSP and/or that different molecular diagnostic approaches are necessary. The accumulating data in this field highlight several peculiar features of HSPs, such as genetic heterogeneity, the discovery that different mutations in a single gene can be transmitted in dominant and recessive trait in families and allelic heterogeneity, resulting in the involvement of HSP-genes in other conditions. Based on the observation of protein functions, the activity of many different proteins encoded by HSP-related genes converges into some distinct pathophysiological mechanisms. This suggests that common pathways could be a potential target for a therapy, possibly addressing several forms at once. Furthermore, the overlap of HSP genes with other neurological conditions can further expand this concept.
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Affiliation(s)
- Emanuele Panza
- Dipartimento di Scienze Mediche e Chirurgiche, Università di Bologna, Bologna, Italy
| | - Arun Meyyazhagan
- Dipartimento di Medicina e Chirurgia, Università di Perugia, Perugia, Italy
| | - Antonio Orlacchio
- Dipartimento di Medicina e Chirurgia, Università di Perugia, Perugia, Italy; Laboratorio di Neurogenetica, Centro Europeo di Ricerca sul Cervello (CERC), Istituto di Ricovero e Cura a Carattere Scientifico (IRCCS) Fondazione Santa Lucia, Rome, Italy.
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11
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Rai M, Curley M, Coleman Z, Demontis F. Contribution of proteases to the hallmarks of aging and to age-related neurodegeneration. Aging Cell 2022; 21:e13603. [PMID: 35349763 PMCID: PMC9124314 DOI: 10.1111/acel.13603] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2022] [Revised: 03/10/2022] [Accepted: 03/13/2022] [Indexed: 12/20/2022] Open
Abstract
Protein quality control ensures the degradation of damaged and misfolded proteins. Derangement of proteostasis is a primary cause of aging and age-associated diseases. The ubiquitin-proteasome and autophagy-lysosome play key roles in proteostasis but, in addition to these systems, the human genome encodes for ~600 proteases, also known as peptidases. Here, we examine the role of proteases in aging and age-related neurodegeneration. Proteases are present across cell compartments, including the extracellular space, and their substrates encompass cellular constituents, proteins with signaling functions, and misfolded proteins. Proteolytic processing by proteases can lead to changes in the activity and localization of substrates or to their degradation. Proteases cooperate with the autophagy-lysosome and ubiquitin-proteasome systems but also have independent proteolytic roles that impact all hallmarks of cellular aging. Specifically, proteases regulate mitochondrial function, DNA damage repair, cellular senescence, nutrient sensing, stem cell properties and regeneration, protein quality control and stress responses, and intercellular signaling. The capacity of proteases to regulate cellular functions translates into important roles in preserving tissue homeostasis during aging. Consequently, proteases influence the onset and progression of age-related pathologies and are important determinants of health span. Specifically, we examine how certain proteases promote the progression of Alzheimer's, Huntington's, and/or Parkinson's disease whereas other proteases protect from neurodegeneration. Mechanistically, cleavage by proteases can lead to the degradation of a pathogenic protein and hence impede disease pathogenesis. Alternatively, proteases can generate substrate byproducts with increased toxicity, which promote disease progression. Altogether, these studies indicate the importance of proteases in aging and age-related neurodegeneration.
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Affiliation(s)
- Mamta Rai
- Department of Developmental NeurobiologySt. Jude Children’s Research HospitalMemphisTennesseeUSA
| | - Michelle Curley
- Department of Developmental NeurobiologySt. Jude Children’s Research HospitalMemphisTennesseeUSA
| | - Zane Coleman
- Department of Developmental NeurobiologySt. Jude Children’s Research HospitalMemphisTennesseeUSA
| | - Fabio Demontis
- Department of Developmental NeurobiologySt. Jude Children’s Research HospitalMemphisTennesseeUSA
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12
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Votsi C, Ververis A, Nicolaou P, Christou YP, Christodoulou K, Zamba-Papanicolaou E. A Novel SPG7 Gene Pathogenic Variant in a Cypriot Family With Autosomal Recessive Spastic Ataxia. Front Genet 2022; 12:812640. [PMID: 35096021 PMCID: PMC8793673 DOI: 10.3389/fgene.2021.812640] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/10/2021] [Accepted: 12/20/2021] [Indexed: 11/13/2022] Open
Abstract
The SPG7 gene encodes the paraplegin protein, an inner mitochondrial membrane—localized protease. It was initially linked to pure and complicated hereditary spastic paraplegia with cerebellar atrophy, and now represents a frequent cause of undiagnosed cerebellar ataxia and spastic ataxia. We hereby report the molecular characterization and the clinical features of a large Cypriot family with five affected individuals presenting with spastic ataxia in an autosomal recessive transmission mode, due to a novel SPG7 homozygous missense variant. Detailed clinical histories of the patients were obtained, followed by neurological and neurophysiological examinations. Whole exome sequencing (WES) of the proband, in silico gene panel analysis, variant filtering and family segregation analysis of the candidate variants with Sanger sequencing were performed. RNA and protein expression as well as in vitro protein localization studies and mitochondria morphology evaluation were carried out towards functional characterization of the identified variant. The patients presented with typical spastic ataxia features while some intrafamilial phenotypic variation was noted. WES analysis revealed a novel homozygous missense variant in the SPG7 gene (c.1763C > T, p. Thr588Met), characterized as pathogenic by more than 20 in silico prediction tools. Functional studies showed that the variant does not affect neither the RNA or protein expression, nor the protein localization. However, aberrant mitochondrial morphology has been observed thus indicating mitochondrial dysfunction and further demonstrating the pathogenicity of the identified variant. Our study is the first report of an SPG7 pathogenic variant in the Cypriot population and broadens the spectrum of SPG7 pathogenic variants.
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Affiliation(s)
- Christina Votsi
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Antonis Ververis
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | - Paschalis Nicolaou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
| | | | - Kyproula Christodoulou
- Neurogenetics Department, The Cyprus Institute of Neurology and Genetics, Nicosia, Cyprus
- *Correspondence: Kyproula Christodoulou,
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13
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Pellegrini C, Pirazzini C, Sala C, Sambati L, Yusipov I, Kalyakulina A, Ravaioli F, Kwiatkowska KM, Durso DF, Ivanchenko M, Monti D, Lodi R, Franceschi C, Cortelli P, Garagnani P, Bacalini MG. A Meta-Analysis of Brain DNA Methylation Across Sex, Age, and Alzheimer's Disease Points for Accelerated Epigenetic Aging in Neurodegeneration. Front Aging Neurosci 2021; 13:639428. [PMID: 33790779 PMCID: PMC8006465 DOI: 10.3389/fnagi.2021.639428] [Citation(s) in RCA: 41] [Impact Index Per Article: 13.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Accepted: 02/05/2021] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is characterized by specific alterations of brain DNA methylation (DNAm) patterns. Age and sex, two major risk factors for AD, are also known to largely affect the epigenetic profiles in brain, but their contribution to AD-associated DNAm changes has been poorly investigated. In this study we considered publicly available DNAm datasets of four brain regions (temporal, frontal, entorhinal cortex, and cerebellum) from healthy adult subjects and AD patients, and performed a meta-analysis to identify sex-, age-, and AD-associated epigenetic profiles. In one of these datasets it was also possible to distinguish 5-methylcytosine (5mC) and 5-hydroxymethylcytosine (5hmC) profiles. We showed that DNAm differences between males and females tend to be shared between the four brain regions, while aging differently affects cortical regions compared to cerebellum. We found that the proportion of sex-dependent probes whose methylation is modified also during aging is higher than expected, but that differences between males and females tend to be maintained, with only a few probes showing age-by-sex interaction. We did not find significant overlaps between AD- and sex-associated probes, nor disease-by-sex interaction effects. On the contrary, we found that AD-related epigenetic modifications are significantly enriched in probes whose DNAm varies with age and that there is a high concordance between the direction of changes (hyper or hypo-methylation) in aging and AD, supporting accelerated epigenetic aging in the disease. In summary, our results suggest that age-associated DNAm patterns concur to the epigenetic deregulation observed in AD, providing new insights on how advanced age enables neurodegeneration.
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Affiliation(s)
- Camilla Pellegrini
- Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Chiara Pirazzini
- Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
| | - Claudia Sala
- Department of Physics and Astronomy, University of Bologna, Bologna, Italy
| | - Luisa Sambati
- Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Igor Yusipov
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky University, Nizhny Novgorod, Russia
| | - Alena Kalyakulina
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky University, Nizhny Novgorod, Russia
| | - Francesco Ravaioli
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Katarzyna M. Kwiatkowska
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
| | - Danielle F. Durso
- Department of Neurology, University of Massachusetts Medical School, Worcester, MA, United States
| | - Mikhail Ivanchenko
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky University, Nizhny Novgorod, Russia
| | - Daniela Monti
- Department of Experimental and Clinical Biomedical Sciences “Mario Serio,” University of Florence, Florence, Italy
| | - Raffaele Lodi
- Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Claudio Franceschi
- Institute of Information Technologies, Mathematics and Mechanics, Lobachevsky University, Nizhny Novgorod, Russia
| | - Pietro Cortelli
- Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
- Department of Biomedical and Neuromotor Sciences, University of Bologna, Bologna, Italy
| | - Paolo Garagnani
- Department of Experimental, Diagnostic and Specialty Medicine, University of Bologna, Bologna, Italy
- Department of Laboratory Medicine, Clinical Chemistry, Karolinska Institutet, Karolinska University Hospital, Stockholm, Sweden
- Applied Biomedical Research Center, Policlinico S.Orsola-Malpighi Polyclinic, Bologna, Italy
- National Research Council of Italy Institute of Molecular Genetics “Luigi Luca Cavalli-Sforza,” Unit of Bologna, Bologna, Italy
| | - Maria Giulia Bacalini
- Istituto di Ricovero e Cura a Carattere Scientifico Istituto delle Scienze Neurologiche di Bologna, Bologna, Italy
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14
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Zeng M, He Y, Du H, Yang J, Wan H. Output Regulation and Function Optimization of Mitochondria in Eukaryotes. Front Cell Dev Biol 2020; 8:598112. [PMID: 33330486 PMCID: PMC7718039 DOI: 10.3389/fcell.2020.598112] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/23/2020] [Accepted: 10/26/2020] [Indexed: 12/23/2022] Open
Abstract
The emergence of endosymbiosis between aerobic alpha-proteobacterium and anaerobic eukaryotic cell precursors opened the chapter of eukaryotic evolution. Multiple functions of mitochondria originated from the ancient precursors of mitochondria and underwent remodeling in eukaryotic cells. Due to the dependence on mitochondrial functions, eukaryotic cells need to constantly adjust mitochondrial output based on energy demand and cellular stress. Meanwhile, eukaryotes conduct the metabolic cooperation between different cells through the involvement of mitochondria. Under some conditions, mitochondria might also be transferred to nearby cells to provide a protective mechanism. However, the endosymbiont relationship determines the existence of various types of mitochondrial injury, such as proteotoxic stress, mutational meltdown, oxidative injure, and immune activation caused by released mitochondrial contents. Eukaryotes have a repertoire of mitochondrial optimization processes, including various mitochondrial quality-control proteins, regulation of mitochondrial dynamics and activation of mitochondrial autophagy. When these quality-control processes fail, eukaryotic cells can activate apoptosis to intercept uncontrolled cell death, thereby minimizing the damage to extracellular tissue. In this review, we describe the intracellular and extracellular context-based regulation of mitochondrial output in eukaryotic cells, and introduce new findings on multifaceted quality-control processes to deal with mitochondrial defects.
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Affiliation(s)
- Miaolin Zeng
- College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Yu He
- College of Pharmaceutical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Haixia Du
- College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Jiehong Yang
- College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, China
| | - Haitong Wan
- College of Basic Medical Science, Zhejiang Chinese Medical University, Hangzhou, China.,College of Life Science, Zhejiang Chinese Medical University, Hangzhou, China
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15
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Pareek G, Pallanck LJ. Inactivation of the mitochondrial protease Afg3l2 results in severely diminished respiratory chain activity and widespread defects in mitochondrial gene expression. PLoS Genet 2020; 16:e1009118. [PMID: 33075064 PMCID: PMC7595625 DOI: 10.1371/journal.pgen.1009118] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2020] [Revised: 10/29/2020] [Accepted: 09/15/2020] [Indexed: 11/18/2022] Open
Abstract
The m-AAA proteases play a critical role in the proteostasis of inner mitochondrial membrane proteins, and mutations in the genes encoding these proteases cause severe incurable neurological diseases. To further explore the biological role of the m-AAA proteases and the pathological consequences of their deficiency, we used a genetic approach in the fruit fly Drosophila melanogaster to inactivate the ATPase family gene 3-like 2 (AFG3L2) gene, which encodes a critical component of the m-AAA proteases. We found that null alleles of Drosophila AFG3L2 die early in development, but partial inactivation of AFG3L2 using RNAi allowed survival to the late pupal and adult stages of development. Flies with partial inactivation of AFG3L2 exhibited behavioral defects, neurodegeneration, accumulation of unfolded mitochondrial proteins, and diminished respiratory chain (RC) activity. Further work revealed that the reduced RC activity was primarily a consequence of severely diminished mitochondrial transcription and translation. These defects were accompanied by activation of the mitochondrial unfolded protein response (mito-UPR) and autophagy. Overexpression of mito-UPR components partially rescued the AFG3L2-deficient phenotypes, indicating that protein aggregation partly accounts for the defects of AFG3L2-deficient animals. Our work suggests that strategies designed to activate mitochondrial stress pathways and mitochondrial gene expression could be therapeutic in the diseases caused by mutations in AFG3L2.
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Affiliation(s)
- Gautam Pareek
- Department of Genome Sciences, University of Washington, Seattle, United States of America
| | - Leo J. Pallanck
- Department of Genome Sciences, University of Washington, Seattle, United States of America
- * E-mail:
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16
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Wali G, Kumar KR, Liyanage E, Davis RL, Mackay-Sim A, Sue CM. Mitochondrial Function in Hereditary Spastic Paraplegia: Deficits in SPG7 but Not SPAST Patient-Derived Stem Cells. Front Neurosci 2020; 14:820. [PMID: 32973427 PMCID: PMC7469654 DOI: 10.3389/fnins.2020.00820] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/15/2020] [Accepted: 07/14/2020] [Indexed: 12/22/2022] Open
Abstract
Mutations in SPG7 and SPAST are common causes of hereditary spastic paraplegia (HSP). While some SPG7 mutations cause paraplegin deficiency, other SPG7 mutations cause increased paraplegin expression. Mitochondrial function has been studied in models that are paraplegin-deficient (human, mouse, and Drosophila models with large exonic deletions, null mutations, or knockout models) but not in models of mutations that express paraplegin. Here, we evaluated mitochondrial function in olfactory neurosphere-derived cells, derived from patients with a variety of SPG7 mutations that express paraplegin and compared them to cells derived from healthy controls and HSP patients with SPAST mutations, as a disease control. We quantified paraplegin expression and an extensive range of mitochondrial morphology measures (fragmentation, interconnectivity, and mass), mitochondrial function measures (membrane potential, oxidative phosphorylation, and oxidative stress), and cell proliferation. Compared to control cells, SPG7 patient cells had increased paraplegin expression, fragmented mitochondria with low interconnectivity, reduced mitochondrial mass, decreased mitochondrial membrane potential, reduced oxidative phosphorylation, reduced ATP content, increased mitochondrial oxidative stress, and reduced cellular proliferation. Mitochondrial dysfunction was specific to SPG7 patient cells and not present in SPAST patient cells, which displayed mitochondrial functions similar to control cells. The mitochondrial dysfunction observed here in SPG7 patient cells that express paraplegin was similar to the dysfunction reported in cell models without paraplegin expression. The p.A510V mutation was common to all patients and was the likely species associated with increased expression, albeit seemingly non-functional. The lack of a mitochondrial phenotype in SPAST patient cells indicates genotype-specific mechanisms of disease in these HSP patients.
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Affiliation(s)
- Gautam Wali
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia
| | - Kishore Raj Kumar
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.,Molecular Medicine Laboratory, Department of Neurology, Concord Hospital, Sydney, NSW, Australia.,Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia.,Department of Neurology, Royal North Shore Hospital, Northern Sydney Local Health District, Sydney, NSW, Australia
| | - Erandhi Liyanage
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia
| | - Ryan L Davis
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.,Kinghorn Centre for Clinical Genomics, Garvan Institute of Medical Research, Sydney, NSW, Australia
| | - Alan Mackay-Sim
- Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.,Griffith Institute for Drug Discovery, Griffith University, Brisbane, QLD, Australia
| | - Carolyn M Sue
- Department of Neurogenetics, Royal North Shore Hospital, Kolling Institute of Medical Research, The University of Sydney, Sydney, NSW, Australia.,Faculty of Medicine and Health, Sydney Medical School, The University of Sydney, Sydney, NSW, Australia.,Department of Neurology, Royal North Shore Hospital, Northern Sydney Local Health District, Sydney, NSW, Australia
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17
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SPG7 mutations in amyotrophic lateral sclerosis: a genetic link to hereditary spastic paraplegia. J Neurol 2020; 267:2732-2743. [PMID: 32447552 PMCID: PMC7419373 DOI: 10.1007/s00415-020-09861-w] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Revised: 04/20/2020] [Accepted: 04/22/2020] [Indexed: 12/11/2022]
Abstract
Amyotrophic lateral sclerosis (ALS) and hereditary spastic paraplegia (HSP) are motor neuron diseases sharing clinical, pathological, and genetic similarities. While biallelic SPG7 mutations are known to cause recessively inherited HSP, heterozygous SPG7 mutations have repeatedly been identified in HSP and recently also in ALS cases. However, the frequency and clinical impact of rare SPG7 variants have not been studied in a larger ALS cohort. Here, whole-exome (WES) or targeted SPG7 sequencing was done in a cohort of 214 European ALS patients. The consequences of a splice site variant were analyzed on the mRNA level. The resulting protein alterations were visualized in a crystal structure model. All patients were subjected to clinical, electrophysiological, and neuroradiological characterization. In 9 of 214 (4.2%) ALS cases, we identified five different rare heterozygous SPG7 variants, all of which were previously reported in patients with HSP or ALS. All detected SPG7 variants affect the AAA+ domain of the encoded mitochondrial metalloprotease paraplegin and impair its stability or function according to predictions from mRNA analysis or crystal structure modeling. ALS patients with SPG7 mutations more frequently presented with cerebellar symptoms, flail arm or leg syndrome compared to those without SPG7 mutations, and showed a partial clinical overlap with HSP. Brain MRI findings in SPG7 mutation carriers included cerebellar atrophy and patterns suggestive of frontotemporal dementia. Collectively, our findings suggest that SPG7 acts as a genetic risk factor for ALS. ALS patients carrying SPG7 mutations present with distinct features overlapping with HSP, particularly regarding cerebellar findings.
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18
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Gibellini L, De Gaetano A, Mandrioli M, Van Tongeren E, Bortolotti CA, Cossarizza A, Pinti M. The biology of Lonp1: More than a mitochondrial protease. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2020; 354:1-61. [PMID: 32475470 DOI: 10.1016/bs.ircmb.2020.02.005] [Citation(s) in RCA: 38] [Impact Index Per Article: 9.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
Initially discovered as a protease responsible for degradation of misfolded or damaged proteins, the mitochondrial Lon protease (Lonp1) turned out to be a multifaceted enzyme, that displays at least three different functions (proteolysis, chaperone activity, binding of mtDNA) and that finely regulates several cellular processes, within and without mitochondria. Indeed, LONP1 in humans is ubiquitously expressed, and is involved in regulation of response to oxidative stress and, heat shock, in the maintenance of mtDNA, in the regulation of mitophagy. Furthermore, its proteolytic activity can regulate several biochemical pathways occurring totally or partially within mitochondria, such as TCA cycle, oxidative phosphorylation, steroid and heme biosynthesis and glutamine production. Because of these multiple activities, Lon protease is highly conserved throughout evolution, and mutations occurring in its gene determines severe diseases in humans, including a rare syndrome characterized by Cerebral, Ocular, Dental, Auricular and Skeletal anomalies (CODAS). Finally, alterations of LONP1 regulation in humans can favor tumor progression and aggressiveness, further highlighting the crucial role of this enzyme in mitochondrial and cellular homeostasis.
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Affiliation(s)
- Lara Gibellini
- Department of Medical and Surgical Sciences of Children and Adults, University of Modena and Reggio Emilia, Modena, Italy
| | - Anna De Gaetano
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Mauro Mandrioli
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | - Elia Van Tongeren
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy
| | | | - Andrea Cossarizza
- Department of Medical and Surgical Sciences of Children and Adults, University of Modena and Reggio Emilia, Modena, Italy
| | - Marcello Pinti
- Department of Life Sciences, University of Modena and Reggio Emilia, Modena, Italy.
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19
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Bozi LHM, Campos JC, Zambelli VO, Ferreira ND, Ferreira JCB. Mitochondrially-targeted treatment strategies. Mol Aspects Med 2019; 71:100836. [PMID: 31866004 DOI: 10.1016/j.mam.2019.100836] [Citation(s) in RCA: 40] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2019] [Revised: 12/11/2019] [Accepted: 12/13/2019] [Indexed: 12/13/2022]
Abstract
Disruption of mitochondrial function is a common feature of inherited mitochondrial diseases (mitochondriopathies) and many other infectious and non-infectious diseases including viral, bacterial and protozoan infections, inflammatory and chronic pain, neurodegeneration, diabetes, obesity and cardiovascular diseases. Mitochondria therefore become an attractive target for developing new therapies. In this review we describe critical mechanisms involved in the maintenance of mitochondrial functionality and discuss strategies used to identify and validate mitochondrial targets in different diseases. We also highlight the most recent preclinical and clinical findings using molecules targeting mitochondrial bioenergetics, morphology, number, content and detoxification systems in common pathologies.
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Affiliation(s)
- Luiz H M Bozi
- Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | - Juliane C Campos
- Institute of Biomedical Sciences, University of Sao Paulo, Brazil
| | | | | | - Julio C B Ferreira
- Institute of Biomedical Sciences, University of Sao Paulo, Brazil; Department of Chemical and Systems Biology, School of Medicine, Stanford University, USA.
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20
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Tarasova NV, Vishnyakova PA, Logashina YA, Elchaninov AV. Mitochondrial Calcium Uniporter Structure and Function in Different Types of Muscle Tissues in Health and Disease. Int J Mol Sci 2019; 20:ijms20194823. [PMID: 31569359 PMCID: PMC6801532 DOI: 10.3390/ijms20194823] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2019] [Revised: 09/12/2019] [Accepted: 09/26/2019] [Indexed: 02/07/2023] Open
Abstract
Calcium ions (Ca2+) influx to mitochondrial matrix is crucial for the life of a cell. Mitochondrial calcium uniporter (mtCU) is a protein complex which consists of the pore-forming subunit (MCU) and several regulatory subunits. MtCU is the main contributor to inward Ca2+ currents through the inner mitochondrial membrane. Extensive investigations of mtCU involvement into normal and pathological molecular pathways started from the moment of discovery of its molecular components. A crucial role of mtCU in the control of these pathways is now recognized in both health and disease. In particular, impairments of mtCU function have been demonstrated for cardiovascular and skeletal muscle-associated pathologies. This review summarizes the current state of knowledge on mtCU structure, regulation, and function in different types of muscle tissues in health and disease.
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Affiliation(s)
- Nadezhda V Tarasova
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, Moscow 119991, Russia.
| | - Polina A Vishnyakova
- National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov of Ministry of Healthcare of Russian Federation, 4 Oparina Street, Moscow 117997, Russia.
| | - Yulia A Logashina
- Sechenov First Moscow State Medical University, Institute of Molecular Medicine, Trubetskaya str. 8, bld. 2, Moscow 119991, Russia.
- Shemyakin-Ovchinnikov Institute of Bioorganic Chemistry, Russian Academy of Sciences, Miklukho-Maklaya Street 16/10, Moscow 117997, Russia.
| | - Andrey V Elchaninov
- National Medical Research Center for Obstetrics, Gynecology and Perinatology Named after Academician V.I. Kulakov of Ministry of Healthcare of Russian Federation, 4 Oparina Street, Moscow 117997, Russia.
- Scientific Research Institute of Human Morphology, 3 Tsurupa Street, Moscow 117418, Russia.
- Peoples' Friendship University of Russia, 6 Miklukho-Maklaya Street, Moscow 117198, Russia.
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21
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Abstract
Parkinson’s disease (PD) is a common neurodegenerative disorder characterized by selective and progressive loss of dopaminergic neurons. Genetic and environmental risk factors are associated with this disease. The genetic factors are composed of approximately 20 genes, such as SNCA, parkin, PTEN-induced kinase1 (pink1), leucine-rich repeat kinase 2 (LRRK2), ATP13A2, MAPT, VPS35, and DJ-1, whereas the environmental factors consist of oxidative stress-induced toxins such as 1-methyl-4-phenyl-1, 2, 3, 6-tetrahydropyridine (MPTP), rotenone, and paraquat. The analyses of their functions and mechanisms have provided important insights into the disease process, which has demonstrated that these factors cause oxidative damage and mitochondrial dysfunction. The most invaluable studies have been performed using disease model organisms, such as mice, fruit flies, and worms. Among them, Drosophila melanogaster has emerged as an excellent model organism to study both environmental and genetic factors and provide insights to the pathways relevant for PD pathogenesis, facilitating development of therapeutic strategies. In this review, we have focused on the fly model organism to summarize recent progress, including pathogenesis, neuro-protective compounds, and newer approaches.
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Affiliation(s)
- Binod Aryal
- Department of Bio and Fermentation Convergence Technology, Kookmin University, BK21 PLUS Project, Seoul 02707, Korea
| | - Youngseok Lee
- Department of Bio and Fermentation Convergence Technology, Kookmin University, BK21 PLUS Project, Seoul 02707, Korea
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22
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Inactivation of Lon protease reveals a link between mitochondrial unfolded protein stress and mitochondrial translation inhibition. Cell Death Dis 2018; 9:1168. [PMID: 30518747 PMCID: PMC6281655 DOI: 10.1038/s41419-018-1213-6] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2018] [Accepted: 11/06/2018] [Indexed: 12/31/2022]
Abstract
The mitochondrial Unfolded Protein Response (UPRmt) pathway confers protection from misfolded and aggregated proteins by activating factors that promote protein folding and degradation. Our recent work on Lon protease, a member of the mitochondrial ATPase Associated with diverse cellular Activities (AAA+) family of mitochondrial resident proteases, suggests that mitochondrial translational inhibition may also be a feature of the UPRmt pathway.
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23
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Samstag CL, Hoekstra JG, Huang CH, Chaisson MJ, Youle RJ, Kennedy SR, Pallanck LJ. Deleterious mitochondrial DNA point mutations are overrepresented in Drosophila expressing a proofreading-defective DNA polymerase γ. PLoS Genet 2018; 14:e1007805. [PMID: 30452458 PMCID: PMC6289449 DOI: 10.1371/journal.pgen.1007805] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/18/2018] [Revised: 12/11/2018] [Accepted: 11/01/2018] [Indexed: 01/08/2023] Open
Abstract
Mitochondrial DNA (mtDNA) mutations cause severe maternally inherited syndromes and the accumulation of somatic mtDNA mutations is implicated in aging and common diseases. However, the mechanisms that influence the frequency and pathogenicity of mtDNA mutations are poorly understood. To address this matter, we created a Drosophila mtDNA mutator strain expressing a proofreading-deficient form of the mitochondrial DNA polymerase. Mutator flies have a dramatically increased somatic mtDNA mutation frequency that correlates with the dosage of the proofreading-deficient polymerase. Mutator flies also exhibit mitochondrial dysfunction, shortened lifespan, a progressive locomotor deficit, and loss of dopaminergic neurons. Surprisingly, the frequency of nonsynonymous, pathogenic, and conserved-site mutations in mutator flies exceeded predictions of a neutral mutational model, indicating the existence of a positive selection mechanism that favors deleterious mtDNA variants. We propose from these findings that deleterious mtDNA mutations are overrepresented because they selectively evade quality control surveillance or because they are amplified through compensatory mitochondrial biogenesis. The energy needs of an animal cell are supplied by tiny organelles known as mitochondria. Each of the many mitochondria in a cell has a set of blueprints for making more mitochondria, known as mitochondrial DNA (mtDNA). As animals age, their mtDNA acquires irreversible defects called mutations, which accumulate and may cause aging. Cells can selectively destroy malfunctioning mitochondria, so we hypothesized that mitochondria with harmful mutations would be selectively destroyed. To test our theory, we created a fruit fly strain with a high mtDNA mutation rate. Our hypothesis predicts that, because mitochondria bearing harmful mtDNA mutations would be destroyed, we should detect primarily less harmful mutations in our strain. However, the mtDNA mutations we detected were more harmful than expected by chance. We suggest two possible explanations: First, mitochondria with harmful mtDNA mutations may be degraded less often because they generate little energy and are not damaged by toxic byproducts of energy production. Second, cells may compensate for harmful mtDNA mutations by stimulating mitochondria to multiply, creating more healthy mitochondria but also more mitochondria with harmful mtDNA mutations. Future studies will distinguish between these models and further advance our understanding of aging and aging related disease.
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Affiliation(s)
- Colby L. Samstag
- Molecular and Cellular Biology Program, University of Washington, Seattle, WA, United States of America
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
| | - Jake G. Hoekstra
- Department of Pathology, University of Washington, Seattle, WA, United States of America
| | - Chiu-Hui Huang
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States of America
| | - Mark J. Chaisson
- Computational Biology and Bioinformatics, University of Southern California, Los Angeles, CA, United States of America
| | - Richard J. Youle
- Surgical Neurology Branch, National Institute of Neurological Disorders and Stroke, National Institutes of Health, Bethesda, MD, United States of America
| | - Scott R. Kennedy
- Department of Pathology, University of Washington, Seattle, WA, United States of America
- * E-mail: (SRK); (LJP)
| | - Leo J. Pallanck
- Department of Genome Sciences, University of Washington, Seattle, WA, United States of America
- * E-mail: (SRK); (LJP)
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24
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Lon protease inactivation in Drosophila causes unfolded protein stress and inhibition of mitochondrial translation. Cell Death Discov 2018; 4:51. [PMID: 30374414 PMCID: PMC6197249 DOI: 10.1038/s41420-018-0110-1] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2018] [Accepted: 09/11/2018] [Indexed: 12/24/2022] Open
Abstract
Mitochondrial dysfunction is a frequent participant in common diseases and a principal suspect in aging. To combat mitochondrial dysfunction, eukaryotes have evolved a large repertoire of quality control mechanisms. One such mechanism involves the selective degradation of damaged or misfolded mitochondrial proteins by mitochondrial resident proteases, including proteases of the ATPase Associated with diverse cellular Activities (AAA+) family. The importance of the AAA+ family of mitochondrial proteases is exemplified by the fact that mutations that impair their functions cause a variety of human diseases, yet our knowledge of the cellular responses to their inactivation is limited. To address this matter, we created and characterized flies with complete or partial inactivation of the Drosophila matrix-localized AAA+ protease Lon. We found that a Lon null allele confers early larval lethality and that severely reducing Lon expression using RNAi results in shortened lifespan, locomotor impairment, and respiratory defects specific to respiratory chain complexes that contain mitochondrially encoded subunits. The respiratory chain defects of Lon knockdown (LonKD) flies appeared to result from severely reduced translation of mitochondrially encoded genes. This translational defect was not a consequence of reduced mitochondrial transcription, as evidenced by the fact that mitochondrial transcripts were elevated in abundance in LonKD flies. Rather, the translational defect of LonKD flies appeared to be derived from sequestration of mitochondrially encoded transcripts in highly dense ribonucleoparticles. The translational defect of LonKD flies was also accompanied by a substantial increase in unfolded mitochondrial proteins. Together, our findings suggest that the accumulation of unfolded mitochondrial proteins triggers a stress response that culminates in the inhibition of mitochondrial translation. Our work provides a foundation to explore the underlying molecular mechanisms.
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Monnier V, Llorens JV, Navarro JA. Impact of Drosophila Models in the Study and Treatment of Friedreich's Ataxia. Int J Mol Sci 2018; 19:E1989. [PMID: 29986523 PMCID: PMC6073496 DOI: 10.3390/ijms19071989] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2018] [Revised: 06/26/2018] [Accepted: 07/03/2018] [Indexed: 02/07/2023] Open
Abstract
Drosophila melanogaster has been for over a century the model of choice of several neurobiologists to decipher the formation and development of the nervous system as well as to mirror the pathophysiological conditions of many human neurodegenerative diseases. The rare disease Friedreich’s ataxia (FRDA) is not an exception. Since the isolation of the responsible gene more than two decades ago, the analysis of the fly orthologue has proven to be an excellent avenue to understand the development and progression of the disease, to unravel pivotal mechanisms underpinning the pathology and to identify genes and molecules that might well be either disease biomarkers or promising targets for therapeutic interventions. In this review, we aim to summarize the collection of findings provided by the Drosophila models but also to go one step beyond and propose the implications of these discoveries for the study and cure of this disorder. We will present the physiological, cellular and molecular phenotypes described in the fly, highlighting those that have given insight into the pathology and we will show how the ability of Drosophila to perform genetic and pharmacological screens has provided valuable information that is not easily within reach of other cellular or mammalian models.
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Affiliation(s)
- Véronique Monnier
- Unité de Biologie Fonctionnelle et Adaptative (BFA), Sorbonne Paris Cité, Université Paris Diderot, UMR8251 CNRS, 75013 Paris, France.
| | - Jose Vicente Llorens
- Department of Genetics, University of Valencia, Campus of Burjassot, 96100 Valencia, Spain.
| | - Juan Antonio Navarro
- Lehrstuhl für Entwicklungsbiologie, Universität Regensburg, 93040 Regensburg, Germany.
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