1
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Nheu D, Petratos S. How does Nogo-A signalling influence mitochondrial function during multiple sclerosis pathogenesis? Neurosci Biobehav Rev 2024; 163:105767. [PMID: 38885889 DOI: 10.1016/j.neubiorev.2024.105767] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2024] [Revised: 05/30/2024] [Accepted: 06/08/2024] [Indexed: 06/20/2024]
Abstract
Multiple sclerosis (MS) is a severe neurological disorder that involves inflammation in the brain, spinal cord and optic nerve with key disabling neuropathological outcomes being axonal damage and demyelination. When degeneration of the axo-glial union occurs, a consequence of inflammatory damage to central nervous system (CNS) myelin, dystrophy and death can lead to large membranous structures from dead oligodendrocytes and degenerative myelin deposited in the extracellular milieu. For the first time, this review covers mitochondrial mechanisms that may be operative during MS-related neurodegenerative changes directly activated during accumulating extracellular deposits of myelin associated inhibitory factors (MAIFs), that include the potent inhibitor of neurite outgrowth, Nogo-A. Axonal damage may occur when Nogo-A binds to and signals through its cognate receptor, NgR1, a multimeric complex, to initially stall axonal transport and limit the delivery of important growth-dependent cargo and subcellular organelles such as mitochondria for metabolic efficiency at sites of axo-glial disintegration as a consequence of inflammation. Metabolic efficiency in axons fails during active demyelination and progressive neurodegeneration, preceded by stalled transport of functional mitochondria to fuel axo-glial integrity.
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Affiliation(s)
- Danica Nheu
- Department of Neuroscience, School of Translational Medicine, Monash University, Prahran, VIC 3004, Australia
| | - Steven Petratos
- Department of Neuroscience, School of Translational Medicine, Monash University, Prahran, VIC 3004, Australia.
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2
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Im S, Jeong DJ, Kim E, Choi JH, Jang HJ, Kim YY, Um JH, Lee J, Lee YJ, Lee KM, Choi D, Yoo E, Lee HS, Yun J. A novel marine-derived mitophagy inducer ameliorates mitochondrial dysfunction and thermal hypersensitivity in paclitaxel-induced peripheral neuropathy. Br J Pharmacol 2024. [PMID: 38925168 DOI: 10.1111/bph.16476] [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: 06/29/2023] [Revised: 02/07/2024] [Accepted: 04/25/2024] [Indexed: 06/28/2024] Open
Abstract
BACKGROUND AND PURPOSE Mitochondrial dysfunction contributes to the pathogenesis and maintenance of chemotherapy-induced peripheral neuropathy (CIPN), a significant limitation of cancer chemotherapy. Recently, the stimulation of mitophagy, a pivotal process for mitochondrial homeostasis, has emerged as a promising treatment strategy for neurodegenerative diseases, but its therapeutic effect on CIPN has not been explored. Here, we assessed the mitophagy-inducing activity of 3,5-dibromo-2-(2',4'-dibromophenoxy)-phenol (PDE701), a diphenyl ether derivative isolated from the marine sponge Dysidea sp., and investigated its therapeutic effect on a CIPN model. EXPERIMENTAL APPROACH Mitophagy activity was determined by a previously established mitophagy assay using mitochondrial Keima (mt-Keima). Mitophagy induction was further verified by western blotting, immunofluorescence, and electron microscopy. Mitochondrial dysfunction was analysed by measuring mitochondrial superoxide levels in SH-SY5Y cells and Drosophila larvae. A thermal nociception assay was used to evaluate the therapeutic effect of PDE701 on the paclitaxel-induced thermal hyperalgesia phenotype in Drosophila larvae. KEY RESULTS PDE701 specifically induced mitophagy but was not toxic to mitochondria. PDE701 ameliorated paclitaxel-induced mitochondrial dysfunction in both SH-SY5Y cells and Drosophila larvae. Importantly, PDE701 also significantly ameliorated paclitaxel-induced thermal hyperalgesia in Drosophila larvae. Knockdown of ATG5 or ATG7 abolished the effect of PDE701 on thermal hyperalgesia, suggesting that PDE701 exerts its therapeutic effect through mitophagy induction. CONCLUSION AND IMPLICATIONS This study identified PDE701 as a novel mitophagy inducer and a potential therapeutic compound for CIPN. Our results suggest that mitophagy stimulation is a promising strategy for the treatment of CIPN and that marine organisms are a potential source of mitophagy-inducing compounds.
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Affiliation(s)
- Sangwoo Im
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, Republic of Korea
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea
| | - Dae Jin Jeong
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, Republic of Korea
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea
| | - Eunmi Kim
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, Republic of Korea
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea
| | - Jae-Hyeong Choi
- Korea Institute of Ocean Science & Technology (KIOST), Busan, Republic of Korea
- Department of Applied Ocean Science, University of Science and Technology, Daejeon, Republic of Korea
| | - Hye-Ji Jang
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, Republic of Korea
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea
| | - Young Yeon Kim
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, Republic of Korea
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea
| | - Jee-Hyun Um
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, Republic of Korea
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea
| | - Jihoon Lee
- Korea Institute of Ocean Science & Technology (KIOST), Busan, Republic of Korea
- Department of Applied Ocean Science, University of Science and Technology, Daejeon, Republic of Korea
| | - Yeon-Ju Lee
- Korea Institute of Ocean Science & Technology (KIOST), Busan, Republic of Korea
- Department of Applied Ocean Science, University of Science and Technology, Daejeon, Republic of Korea
| | - Kang-Min Lee
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, Republic of Korea
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea
| | - Dabin Choi
- Altmedical Co., Ltd, Seoul, Republic of Korea
| | - Eunhee Yoo
- Altmedical Co., Ltd, Seoul, Republic of Korea
| | - Hyi-Seung Lee
- Korea Institute of Ocean Science & Technology (KIOST), Busan, Republic of Korea
- Department of Applied Ocean Science, University of Science and Technology, Daejeon, Republic of Korea
| | - Jeanho Yun
- Department of Biochemistry, College of Medicine, Dong-A University, Busan, Republic of Korea
- Department of Translational Biomedical Sciences, Graduate School of Dong-A University, Busan, Republic of Korea
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3
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Bernard A, Mroué M, Bourthoumieu S, Boyce M, Richard L, Sturtz F, Demiot C, Danigo A. Netazepide, an Antagonist of Cholecystokinin Type 2 Receptor, Prevents Vincristine-Induced Sensory Neuropathy in Mice. Pharmaceuticals (Basel) 2024; 17:144. [PMID: 38399359 PMCID: PMC10892341 DOI: 10.3390/ph17020144] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2023] [Revised: 01/12/2024] [Accepted: 01/19/2024] [Indexed: 02/25/2024] Open
Abstract
Among the vinca-alkaloid class, vincristine is a potent chemotherapeutic agent with significant neurotoxic effects and is employed to address a wide spectrum of cancer types. Recently, the therapeutic potential of the cholecystokinin type 2 receptor (CCK2R) as a target for vincristine-induced peripheral neuropathy (VIPN) was demonstrated. In this study, the impact of preventive CCK2R blockade using netazepide (Trio Medicines Ltd., London, UK) was investigated in a mouse model of vincristine-induced peripheral neuropathy. Netazepide is a highly selective CCK2R antagonist under development for the treatment of patients with gastric neuroendocrine tumors caused by hypergastrinemia secondary to chronic autoimmune atrophic gastritis. Vincristine-induced peripheral neuropathy was induced by intraperitoneal injections of vincristine at 100 µg/kg/d for 7 days (D0 to D7). Netazepide (2 mg/kg/d or 5 mg/kg/d, per os) was administered one day before vincristine treatment until D7. Vincristine induced a high tactile allodynia from D1 to D7. VIPN was characterized by dorsal root ganglion neuron (DRG) and intraepidermal nerve fiber (IENF) loss, and enlargement and loss of myelinated axons in the sciatic nerve. Netazepide completely prevented the painful symptoms and nerve injuries induced by vincristine. In conclusion, the fact that netazepide protected against vincristine-induced peripheral neuropathy in a mouse model strongly supports the assessment of its therapeutic potential in patients receiving such chemotherapy.
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Affiliation(s)
- Amandine Bernard
- NeurIT Neuropathies et Innovations Thérapeutiques UR 20218, Faculties of Medicine and Pharmacy, University of Limoges, 87025 Limoges, France; (A.B.); (M.M.); (S.B.); (L.R.); (F.S.); (C.D.)
| | - Mohamad Mroué
- NeurIT Neuropathies et Innovations Thérapeutiques UR 20218, Faculties of Medicine and Pharmacy, University of Limoges, 87025 Limoges, France; (A.B.); (M.M.); (S.B.); (L.R.); (F.S.); (C.D.)
| | - Sylvie Bourthoumieu
- NeurIT Neuropathies et Innovations Thérapeutiques UR 20218, Faculties of Medicine and Pharmacy, University of Limoges, 87025 Limoges, France; (A.B.); (M.M.); (S.B.); (L.R.); (F.S.); (C.D.)
- Department of Cytogenetic, Medical Genetic and Reproduction Biology, University Hospital of Limoges, 87042 Limoges, France
| | - Malcolm Boyce
- Hammersmith Medicines Research Limited and Trio Medicines Limited, 44 Cumberland Avenue, London NW10 7EW, UK;
| | - Laurence Richard
- NeurIT Neuropathies et Innovations Thérapeutiques UR 20218, Faculties of Medicine and Pharmacy, University of Limoges, 87025 Limoges, France; (A.B.); (M.M.); (S.B.); (L.R.); (F.S.); (C.D.)
- Department of Neurology, Reference Center for Rare Peripheral Neuropathies, University Hospital of Limoges, 87042 Limoges, France
| | - Franck Sturtz
- NeurIT Neuropathies et Innovations Thérapeutiques UR 20218, Faculties of Medicine and Pharmacy, University of Limoges, 87025 Limoges, France; (A.B.); (M.M.); (S.B.); (L.R.); (F.S.); (C.D.)
- Department of Biochemistry and Molecular Genetics, University Hospital of Limoges, 87042 Limoges, France
| | - Claire Demiot
- NeurIT Neuropathies et Innovations Thérapeutiques UR 20218, Faculties of Medicine and Pharmacy, University of Limoges, 87025 Limoges, France; (A.B.); (M.M.); (S.B.); (L.R.); (F.S.); (C.D.)
- Transversal and Territorial Therapeutic Education Unit (UTTEP87), University Hospital of Limoges, 87042 Limoges, France
| | - Aurore Danigo
- NeurIT Neuropathies et Innovations Thérapeutiques UR 20218, Faculties of Medicine and Pharmacy, University of Limoges, 87025 Limoges, France; (A.B.); (M.M.); (S.B.); (L.R.); (F.S.); (C.D.)
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4
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Kotaich F, Caillol D, Bomont P. Neurofilaments in health and Charcot-Marie-Tooth disease. Front Cell Dev Biol 2023; 11:1275155. [PMID: 38164457 PMCID: PMC10758125 DOI: 10.3389/fcell.2023.1275155] [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: 08/09/2023] [Accepted: 10/02/2023] [Indexed: 01/03/2024] Open
Abstract
Neurofilaments (NFs) are the most abundant component of mature neurons, that interconnect with actin and microtubules to form the cytoskeleton. Specifically expressed in the nervous system, NFs present the particularity within the Intermediate Filament family of being formed by four subunits, the neurofilament light (NF-L), medium (NF-M), heavy (NF-H) proteins and α-internexin or peripherin. Here, we review the current knowledge on NF proteins and neurofilaments, from their domain structures and their model of assembly to the dynamics of their transport and degradation along the axon. The formation of the filament and its behaviour are regulated by various determinants, including post-transcriptional (miRNA and RBP proteins) and post-translational (phosphorylation and ubiquitination) modifiers. Altogether, the complex set of modifications enable the neuron to establish a stable but elastic NF array constituting the structural scaffold of the axon, while permitting the local expression of NF proteins and providing the dynamics necessary to fulfil local demands and respond to stimuli and injury. Thus, in addition to their roles in mechano-resistance, radial axonal outgrowth and nerve conduction, NFs control microtubule dynamics, organelle distribution and neurotransmission at the synapse. We discuss how the studies of neurodegenerative diseases with NF aggregation shed light on the biology of NFs. In particular, the NEFL and NEFH genes are mutated in Charcot-Marie-Tooth (CMT) disease, the most common inherited neurological disorder of the peripheral nervous system. The clinical features of the CMT forms (axonal CMT2E, CMT2CC; demyelinating CMT1F; intermediate I-CMT) with symptoms affecting the central nervous system (CNS) will allow us to further investigate the physiological roles of NFs in the brain. Thus, NF-CMT mouse models exhibit various degrees of sensory-motor deficits associated with CNS symptoms. Cellular systems brought findings regarding the dominant effect of NF-L mutants on NF aggregation and transport, although these have been recently challenged. Neurofilament detection without NF-L in recessive CMT is puzzling, calling for a re-examination of the current model in which NF-L is indispensable for NF assembly. Overall, we discuss how the fundamental and translational fields are feeding each-other to increase but also challenge our knowledge of NF biology, and to develop therapeutic avenues for CMT and neurodegenerative diseases with NF aggregation.
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Affiliation(s)
| | | | - Pascale Bomont
- ERC team, NeuroMyoGene Institute-Pathophysiology and Genetics of Neuron and Muscle, Inserm U1315, CNRS UMR5261, University of Lyon 1, Lyon, France
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5
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Funakoshi M, Araki T. Mechanism of initiation and regulation of axonal degeneration with special reference to NMNATs and Sarm1. Neurosci Res 2023; 197:3-8. [PMID: 34767875 DOI: 10.1016/j.neures.2021.11.002] [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: 11/01/2021] [Accepted: 11/01/2021] [Indexed: 10/19/2022]
Abstract
Axonal degeneration is observed in a variety of contexts in both the central and peripheral nervous systems. Pathological signaling to regulate the progression of axonal degeneration has long been studied using Wallerian degeneration, the prototypical axonal degradation observed after injury, as a representative model. Understanding metabolism of nicotinamide adenine dinucleotide (NAD+) and the functional regulation of Sarm1 has generated great progress in this field, but there are a number of remaining questions. Here, in this short review, we describe our current understanding of the axonal degeneration mechanism, with special reference to the biology related to wlds mice and Sarm1. Furthermore, variations of axonal degeneration initiation are discussed in order to address the remaining questions needed for mechanistic clarification.
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Affiliation(s)
- Masabumi Funakoshi
- Department of Peripheral Nervous System Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan
| | - Toshiyuki Araki
- Department of Peripheral Nervous System Research, National Institute of Neuroscience, National Center of Neurology and Psychiatry, 4-1-1 Ogawa-Higashi, Kodaira, Tokyo, 187-8502, Japan.
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6
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Dan L, Zhang Z. Alzheimer's disease: an axonal injury disease? Front Aging Neurosci 2023; 15:1264448. [PMID: 37927337 PMCID: PMC10620718 DOI: 10.3389/fnagi.2023.1264448] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/20/2023] [Accepted: 09/14/2023] [Indexed: 11/07/2023] Open
Abstract
Alzheimer's disease (AD) is the primary cause of dementia and is anticipated to impose a substantial economic burden in the future. Over a significant period, the widely accepted amyloid cascade hypothesis has guided research efforts, and the recent FDA approval of an anti- amyloid-beta (Aβ) protofibrils antibody, believed to decelerate AD progression, has further solidified its significance. However, the excessive emphasis placed on the amyloid cascade hypothesis has overshadowed the physiological nature of Aβ and tau proteins within axons. Axons, specialized neuronal structures, sustain damage during the early stages of AD, exerting a pivotal influence on disease progression. In this review, we present a comprehensive summary of the relationship between axonal damage and AD pathology, amalgamating the physiological roles of Aβ and tau proteins, along with the impact of AD risk genes such as APOE and TREM2. Furthermore, we underscore the exceptional significance of axonal damage in the context of AD.
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Affiliation(s)
| | - Zhaohui Zhang
- Department of Neurology, Renmin Hospital of Wuhan University, Wuhan, Hubei, China
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7
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Li X, Zhang T, Li C, Xu W, Guan Y, Li X, Cheng H, Chen S, Yang B, Liu Y, Ren Z, Song X, Jia Z, Wang Y, Tang J. Electrical stimulation accelerates Wallerian degeneration and promotes nerve regeneration after sciatic nerve injury. Glia 2023; 71:758-774. [PMID: 36484493 DOI: 10.1002/glia.24309] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2022] [Revised: 11/12/2022] [Accepted: 11/14/2022] [Indexed: 12/13/2022]
Abstract
Following peripheral nerve injury (PNI), Wallerian degeneration (WD) in the distal stump can generate a microenvironment favorable for nerve regeneration. Brief low-frequency electrical stimulation (ES) is an effective treatment for PNI, but the mechanism underlying its effect on WD remains unclear. Therefore, we hypothesized that ES could enhance nerve regeneration by accelerating WD. To verify this hypothesis, we used a rat model of sciatic nerve transection and provided ES at the distal stump of the injured nerve. The injured nerve was then evaluated after 1, 4, 7, 14 and 21 days post injury (dpi). The results showed that ES significantly promoted the degeneration and clearance of axons and myelin, and the dedifferentiation of Schwann cells. It upregulated the expression of BDNF and NGF and increased the number of monocytes and macrophages. Through transcriptome sequencing, we systematically investigated the effect of ES on the molecular processes involved in WD at 4 dpi. Evaluation of nerves bridged using silicone tubing after transection showed that ES accelerated early axonal and vascular regeneration while delaying gastrocnemius atrophy. These results demonstrate that ES promotes nerve regeneration by accelerating WD and upregulating the expression of neurotrophic factors.
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Affiliation(s)
- Xiangling Li
- The School of Medicine, Jinzhou Medical University, Jinzhou, China.,Department of Orthopedics, The Fourth Medical Center of the General Hospital of People's Liberation Army, Beijing, China.,Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Tieyuan Zhang
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Chaochao Li
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Wenjing Xu
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Yanjun Guan
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Xiaoya Li
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Haofeng Cheng
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China.,School of Medicine, Nankai University, Tianjin, China
| | - Shengfeng Chen
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Boyao Yang
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Yuli Liu
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Zhiqi Ren
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China
| | - Xiangyu Song
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China.,School of Medicine, Hebei North University, Zhangjiakou, China
| | - Zhibo Jia
- Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China.,School of Medicine, Hebei North University, Zhangjiakou, China
| | - Yu Wang
- Department of Orthopedics, The Fourth Medical Center of the General Hospital of People's Liberation Army, Beijing, China.,Institute of Orthopedics, Chinese PLA General Hospital, Beijing Key Lab of Regenerative Medicine in Orthopedics, Key Laboratory of Musculoskeletal Trauma and War Injuries PLA, Beijing, China.,Co-Innovation Center of Neuroregeneration, Nantong University, Nantong, China
| | - Jinshu Tang
- Department of Orthopedics, The Fourth Medical Center of the General Hospital of People's Liberation Army, Beijing, China
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Wang J, Liu WJ, Shi HZ, Zhai HR, Qian JJ, Zhang WN. A Role for PGC-1a in the Control of Abnormal Mitochondrial Dynamics in Alzheimer’s Disease. Cells 2022; 11:cells11182849. [PMID: 36139423 PMCID: PMC9496770 DOI: 10.3390/cells11182849] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/18/2022] [Revised: 09/03/2022] [Accepted: 09/09/2022] [Indexed: 11/17/2022] Open
Abstract
Emerging evidence suggests that the proper control of mitochondrial dynamics provides a window for therapeutic intervention for Alzheimer’s disease (AD) progression. The transcriptional coactivator peroxisome proliferator activated receptor gamma coactivator 1 (PGC-1a) has been shown to regulate mitochondrial biogenesis in neurons. Thus far, the roles of PGC-1a in Alzheimer’s disease and its potential value for restoring mitochondrial dysfunction remain largely unknown. In the present study, we explored the impacts of PGC-1a on AD pathology and neurobehavioral dysfunction and its potential mechanisms with a particular focus on mitochondrial dynamics. Paralleling AD-related pathological deposits, neuronal apoptosis, abnormal mitochondrial dynamics and lowered membrane potential, a remarkable reduction in the expression of PGC-1a was shown in the cortex of APP/PS1 mice at 6 months of age. By infusing AAV-Ppargc1α into the lateral parietal association (LPtA) cortex of the APP/PS1 brain, we found that PGC-1a ameliorated AD-like behavioral abnormalities, such as deficits in spatial reference memory, working memory and sensorimotor gating. Notably, overexpressed PGC-1a in LPtA rescued mitochondrial swelling and damage in neurons, likely through correcting the altered balance in mitochondrial fission–fusion and its abnormal distribution. Our findings support the notion that abnormal mitochondrial dynamics is likely an important mechanism that leading to mitochondrial dysfunction and AD-related pathological and cognitive impairments, and they indicate the potential value of PGC-1a for restoring mitochondrial dynamics as an innovative therapeutic target for AD.
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Affiliation(s)
- Jia Wang
- The Fourth Affiliated Hospital of Jiangsu University, Zhenjiang 212001, China
- Department of Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang 212013, China
- Correspondence: (J.W.); (W.-N.Z.)
| | - Wen-Jun Liu
- Department of Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang 212013, China
| | - Hou-Zhen Shi
- Department of Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang 212013, China
| | - Hong-Ru Zhai
- Department of Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang 212013, China
| | - Jin-Jun Qian
- The Fourth Affiliated Hospital of Jiangsu University, Zhenjiang 212001, China
| | - Wei-Ning Zhang
- Department of Laboratory Medicine, School of Medicine, Jiangsu University, Zhenjiang 212013, China
- Correspondence: (J.W.); (W.-N.Z.)
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Vanisova M, Stufkova H, Kohoutova M, Rakosnikova T, Krizova J, Klempir J, Rysankova I, Roth J, Zeman J, Hansikova H. Mitochondrial organization and structure are compromised in fibroblasts from patients with Huntington's disease. Ultrastruct Pathol 2022; 46:462-475. [PMID: 35946926 DOI: 10.1080/01913123.2022.2100951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/15/2022]
Abstract
Huntington´s disease (HD) is a progressive neurodegenerative disease with onset in adulthood that leads to a complete disability and death in approximately 20 years after onset of symptoms. HD is caused by an expansion of a CAG triplet in the gene for huntingtin. Although the disease causes most damage to striatal neurons, other parts of the nervous system and many peripheral tissues are also markedly affected. Besides huntingtin malfunction, mitochondrial impairment has been previously described as an important player in HD. This study focuses on mitochondrial structure and function in cultivated skin fibroblasts from 10 HD patients to demonstrate mitochondrial impairment in extra-neuronal tissue. Mitochondrial structure, mitochondrial fission, and cristae organization were significantly disrupted and signs of elevated apoptosis were found. In accordance with structural changes, we also found indicators of functional alteration of mitochondria. Mitochondrial disturbances presented in fibroblasts from HD patients confirm that the energy metabolism damage in HD is not localized only to the central nervous system, but also may play role in the pathogenesis of HD in peripheral tissues. Skin fibroblasts can thus serve as a suitable cellular model to make insight into HD pathobiochemical processes and for the identification of possible targets for new therapies.
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Affiliation(s)
- Marie Vanisova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Hana Stufkova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Michaela Kohoutova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Tereza Rakosnikova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Jana Krizova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Jiri Klempir
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Irena Rysankova
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Jan Roth
- Department of Neurology and Centre of Clinical Neuroscience, First Faculty of Medicine, Charles University and General University Hospital, Prague, Czech Republic
| | - Jiri Zeman
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
| | - Hana Hansikova
- Department of Paediatrics and Inherited Metabolic Disorders, First Faculty of Medicine, Charles University and General University Hospital in Prague, Prague, Czech Republic
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10
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Babetto E, Beirowski B. Of axons that struggle to make ends meet: Linking axonal bioenergetic failure to programmed axon degeneration. BIOCHIMICA ET BIOPHYSICA ACTA. BIOENERGETICS 2022; 1863:148545. [PMID: 35339437 DOI: 10.1016/j.bbabio.2022.148545] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 03/07/2022] [Accepted: 03/16/2022] [Indexed: 02/07/2023]
Abstract
Axons are the long, fragile, and energy-hungry projections of neurons that are challenging to sustain. Together with their associated glia, they form the bulk of the neuronal network. Pathological axon degeneration (pAxD) is a driver of irreversible neurological disability in a host of neurodegenerative conditions. Halting pAxD is therefore an attractive therapeutic strategy. Here we review recent work demonstrating that pAxD is regulated by an auto-destruction program that revolves around axonal bioenergetics. We then focus on the emerging concept that axonal and glial energy metabolism are intertwined. We anticipate that these discoveries will encourage the pursuit of new treatment strategies for neurodegeneration.
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Affiliation(s)
- Elisabetta Babetto
- Institute for Myelin and Glia Exploration, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA; Department of Pharmacology and Toxicology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA.
| | - Bogdan Beirowski
- Institute for Myelin and Glia Exploration, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14203, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA.
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11
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Beirowski B. Emerging evidence for compromised axonal bioenergetics and axoglial metabolic coupling as drivers of neurodegeneration. Neurobiol Dis 2022; 170:105751. [PMID: 35569720 DOI: 10.1016/j.nbd.2022.105751] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2022] [Revised: 04/20/2022] [Accepted: 05/09/2022] [Indexed: 10/18/2022] Open
Abstract
Impaired bioenergetic capacity of the nervous system is thought to contribute to the pathogenesis of many neurodegenerative diseases (NDD). Since neuronal synapses are believed to be the major energy consumers in the nervous system, synaptic derangements resulting from energy deficits have been suggested to play a central role for the development of many of these disorders. However, long axons constitute the largest compartment of the neuronal network, require large amounts of energy, are metabolically and structurally highly vulnerable, and undergo early injurious stresses in many NDD. These stresses likely impose additional energy demands for continuous adaptations and repair processes, and may eventually overwhelm axonal maintenance mechanisms. Indeed, pathological axon degeneration (pAxD) is now recognized as an etiological focus in a wide array of NDD associated with bioenergetic abnormalities. In this paper I first discuss the recognition that a simple experimental model for pAxD is regulated by an auto-destruction program that exhausts distressed axons energetically. Provision of the energy substrate pyruvate robustly counteracts this axonal breakdown. Importantly, energy decline in axons is not only a consequence but also an initiator of this program. This opens the intriguing possibility that axon dysfunction and pAxD can be suppressed by preemptively energizing distressed axons. Second, I focus on the emerging concept that axons communicate energetically with their flanking glia. This axoglial metabolic coupling can help offset the axonal energy decline that activates the pAxD program but also jeopardize axon integrity as a result of perturbed glial metabolism. Third, I present compelling evidence that abnormal axonal energetics and compromised axoglial metabolic coupling accompany the activation of the pAxD auto-destruction pathway in models of glaucoma, a widespread neurodegenerative condition with pathogenic overlap to other common NDD. In conclusion, I propose a novel conceptual framework suggesting that therapeutic interventions focused on bioenergetic support of the nervous system should also address axons and their metabolic interactions with glia.
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Affiliation(s)
- Bogdan Beirowski
- Institute for Myelin and Glia Exploration, New York State Center of Excellence in Bioinformatics & Life Sciences (CBLS), University at Buffalo, Buffalo, NY 14203, USA; Department of Biochemistry, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY 14214, USA.
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12
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Yang Y, Chen X, Feng Z, Cai X, Zhu X, Cao M, Yang L, Chen Y, Wang Y, Feng H. MEC17-induced α-tubulin acetylation restores mitochondrial transport function and alleviates axonal injury after intracerebral hemorrhage in mice. J Neurochem 2021; 160:51-63. [PMID: 34407220 DOI: 10.1111/jnc.15493] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Revised: 07/25/2021] [Accepted: 08/09/2021] [Indexed: 02/01/2023]
Abstract
Injury to long axonal projections is a central pathological feature at the early phase of intracerebral hemorrhage (ICH). It has been reported to contribute to persistent functional disability following ICH. However, the molecular mechanisms that drive axonal degeneration remain unclear. Autologous blood was injected into the striatum to mimic the pathology of ICH. Observed significant swollen axons with characteristic retraction bulbs were found around the striatal hematoma at 24 h after ICH. Electronic microscopic examination revealed highly disorganized microtubule and swollen mitochondria in the retraction bulbs. MEC17 is a specific α-tubulin acetyltransferase, ablation of acetylated α-tubulin in MEC17-/- mice aggravated axonal injury, axonal transport mitochondria dysfunction, and motor dysfunction. In contrast, treatment with tubastatin A (TubA), which promotes microtubule acetylation, significantly alleviated axonal injury and protected the integrity of the corticospinal tract and fine motor function after ICH. Moreover, results showed that 41% mitochondria were preferentially bundled to the acetylated α-tubulin in identifiable axons and dendrites in primary neurons. This impaired axonal transport of mitochondria in primary neurons of MEC17-/- mice. Given that opening of mitochondrial permeability transition pore (mPTP) induces mitochondrial dysfunction and impairs ATP supply thereby promoting axonal injury, we enhanced the availability of acetylated α-tubulin using TubA and inhibited mPTP opening with cyclosporin A. The results indicated that this combined treatment synergistically protected corticospinal tract integrity and promoted fine motor control recovery. These findings reveal key intracellular mechanisms that drive axonal degeneration after ICH and highlight the need to target multiple factors and respective regulatory mechanisms as an effective approach to prevent axonal degeneration and motor dysfunction after ICH.
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Affiliation(s)
- Yang Yang
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China.,Department of Neurosurgery and State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University, Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Third Military Medical University (Army Medical University, Chongqing, China.,Wuxi Translational Medicine Center, Wuxi, Jiangsu, China
| | - Xuezhu Chen
- Department of Neurosurgery and State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University, Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Third Military Medical University (Army Medical University, Chongqing, China
| | - Zhizhong Feng
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China
| | - Xianfeng Cai
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China
| | - Xiaoming Zhu
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China
| | - Ming Cao
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China
| | - Likun Yang
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China.,Wuxi Translational Medicine Center, Wuxi, Jiangsu, China
| | - Yujie Chen
- Department of Neurosurgery and State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University, Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Third Military Medical University (Army Medical University, Chongqing, China
| | - Yuhai Wang
- Department of Neurosurgery, The 904th Hospital of PLA, School of Medicine of Anhui Medical University, Wuxi, Jiangsu Province, China.,Wuxi Translational Medicine Center, Wuxi, Jiangsu, China
| | - Hua Feng
- Department of Neurosurgery and State Key Laboratory of Trauma, Burn and Combined Injury, Southwest Hospital, Third Military Medical University (Army Medical University, Chongqing, China.,Chongqing Key Laboratory of Precision Neuromedicine and Neuroregenaration, Third Military Medical University (Army Medical University, Chongqing, China
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Abstract
Significant advances have been made in recent years in identifying the genetic components of Wallerian degeneration, the process that brings the progressive destruction and removal of injured axons. It has now been accepted that Wallerian degeneration is an active and dynamic cellular process that is well regulated at molecular and cellular levels. In this review, we describe our current understanding of Wallerian degeneration, focusing on the molecular players and mechanisms that mediate the injury response, activate the degenerative program, transduce the death signal, execute the destruction order, and finally, clear away the debris. By highlighting the starring roles and sketching out the molecular script of Wallerian degeneration, we hope to provide a useful framework to understand Wallerian and Wallerian-like degeneration and to lay a foundation for developing new therapeutic strategies to treat axon degeneration in neural injury as well as in neurodegenerative disease. Expected final online publication date for the Annual Review of Genetics, Volume 55 is November 2021. Please see http://www.annualreviews.org/page/journal/pubdates for revised estimates.
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Affiliation(s)
- Kai Zhang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201203, China; , , .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Mingsheng Jiang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201203, China; , , .,University of Chinese Academy of Sciences, Beijing 100049, China
| | - Yanshan Fang
- Interdisciplinary Research Center on Biology and Chemistry, Shanghai Institute of Organic Chemistry, Chinese Academy of Sciences, Shanghai 201203, China; , , .,University of Chinese Academy of Sciences, Beijing 100049, China
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Doyle TM, Salvemini D. Mini-Review: Mitochondrial dysfunction and chemotherapy-induced neuropathic pain. Neurosci Lett 2021; 760:136087. [PMID: 34182057 DOI: 10.1016/j.neulet.2021.136087] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/25/2021] [Accepted: 06/14/2021] [Indexed: 02/07/2023]
Abstract
Chemotherapy-induced peripheral neuropathy (CIPN) is a somatosensory axonopathy in cancer patients receiving any of a variety of widely-use antitumor agents. CIPN can lead to long-lasting neuropathic pain that limits the dose or length of otherwise life-saving cancer therapy. Accumulating evidence over the last two decades indicates that many chemotherapeutic agents cause mitochondrial injury in the peripheral sensory nerves by disrupting mitochondrial structure and bioenergetics, increasing nitro-oxidative stress and altering mitochondrial transport, fission, fusion and mitophagy. The accumulation of abnormal and dysfunctional mitochondria in sensory neurons are linked to axonal growth defects resulting in the loss of intraepidermal nerve fibers in the hands and feet, increased spontaneous discharge and the sensitization of peripheral sensory neurons that provoke and promote changes in the central nervous system that establish a chronic neuropathic pain state. This has led to the propose mitotoxicity theory of CIPN. Strategies that improve mitochondrial function have shown success in preventing and reversing CIPN in pre-clinical animal models and have begun to show some progress toward translation to the clinic. In this review, we will review the evidence for, the causes and effects of and current strategies to target mitochondrial dysfunction in CIPN.
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Affiliation(s)
- Timothy M Doyle
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd, St. Louis, MO 63104, USA; Henry and Amelia Nasrallah Center for Neuroscience, Saint Louis University School of Medicine, 1402 S. Grand Blvd, St. Louis, MO 63104, USA
| | - Daniela Salvemini
- Department of Pharmacology and Physiology, Saint Louis University School of Medicine, 1402 S. Grand Blvd, St. Louis, MO 63104, USA; Henry and Amelia Nasrallah Center for Neuroscience, Saint Louis University School of Medicine, 1402 S. Grand Blvd, St. Louis, MO 63104, USA.
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15
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Machine learning-based classification of mitochondrial morphology in primary neurons and brain. Sci Rep 2021; 11:5133. [PMID: 33664336 PMCID: PMC7933342 DOI: 10.1038/s41598-021-84528-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/25/2020] [Accepted: 02/17/2021] [Indexed: 01/31/2023] Open
Abstract
The mitochondrial network continually undergoes events of fission and fusion. Under physiologic conditions, the network is in equilibrium and is characterized by the presence of both elongated and punctate mitochondria. However, this balanced, homeostatic mitochondrial profile can change morphologic distribution in response to various stressors. Therefore, it is imperative to develop a method that robustly measures mitochondrial morphology with high accuracy. Here, we developed a semi-automated image analysis pipeline for the quantitation of mitochondrial morphology for both in vitro and in vivo applications. The image analysis pipeline was generated and validated utilizing images of primary cortical neurons from transgenic mice, allowing genetic ablation of key components of mitochondrial dynamics. This analysis pipeline was further extended to evaluate mitochondrial morphology in vivo through immunolabeling of brain sections as well as serial block-face scanning electron microscopy. These data demonstrate a highly specific and sensitive method that accurately classifies distinct physiological and pathological mitochondrial morphologies. Furthermore, this workflow employs the use of readily available, free open-source software designed for high throughput image processing, segmentation, and analysis that is customizable to various biological models.
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16
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Shahsavani N, Kataria H, Karimi-Abdolrezaee S. Mechanisms and repair strategies for white matter degeneration in CNS injury and diseases. Biochim Biophys Acta Mol Basis Dis 2021; 1867:166117. [PMID: 33667627 DOI: 10.1016/j.bbadis.2021.166117] [Citation(s) in RCA: 14] [Impact Index Per Article: 4.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/21/2020] [Revised: 02/22/2021] [Accepted: 02/23/2021] [Indexed: 12/14/2022]
Abstract
White matter degeneration is an important pathophysiological event of the central nervous system that is collectively characterized by demyelination, oligodendrocyte loss, axonal degeneration and parenchymal changes that can result in sensory, motor, autonomic and cognitive impairments. White matter degeneration can occur due to a variety of causes including trauma, neurotoxic exposure, insufficient blood flow, neuroinflammation, and developmental and inherited neuropathies. Regardless of the etiology, the degeneration processes share similar pathologic features. In recent years, a plethora of cellular and molecular mechanisms have been identified for axon and oligodendrocyte degeneration including oxidative damage, calcium overload, neuroinflammatory events, activation of proteases, depletion of adenosine triphosphate and energy supply. Extensive efforts have been also made to develop neuroprotective and neuroregenerative approaches for white matter repair. However, less progress has been achieved in this area mainly due to the complexity and multifactorial nature of the degeneration processes. Here, we will provide a timely review on the current understanding of the cellular and molecular mechanisms of white matter degeneration and will also discuss recent pharmacological and cellular therapeutic approaches for white matter protection as well as axonal regeneration, oligodendrogenesis and remyelination.
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Affiliation(s)
- Narjes Shahsavani
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Spinal Cord Research Centre, Children's Hospital Research Institute of Manitoba, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Hardeep Kataria
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Spinal Cord Research Centre, Children's Hospital Research Institute of Manitoba, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada
| | - Soheila Karimi-Abdolrezaee
- Department of Physiology and Pathophysiology, Regenerative Medicine Program, Spinal Cord Research Centre, Children's Hospital Research Institute of Manitoba, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, Manitoba, Canada.
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CAILLAUD M, PATEL NH, WHITE A, WOOD M, Contreras KM, TOMA W, Alkhlaif Y, ROBERTS JL, Tran TH, JACKSON AB, POKLIS J, GEWIRTZ DA, DAMAJ MI. Targeting Peroxisome Proliferator-Activated Receptor-α (PPAR- α) to reduce paclitaxel-induced peripheral neuropathy. Brain Behav Immun 2021; 93:172-185. [PMID: 33434562 PMCID: PMC8226373 DOI: 10.1016/j.bbi.2021.01.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/22/2020] [Revised: 01/05/2021] [Accepted: 01/06/2021] [Indexed: 01/27/2023] Open
Abstract
BACKGROUND AND PURPOSE Paclitaxel, a widely used anti-cancer drug, is frequently associated with prolonged and severe peripheral neuropathies (PIPN), associated with neuroinflammation. Currently, PIPN effective treatments are lacking. Peroxisome Proliferator-Activated Receptor-α (PPAR-⍺) can modulate inflammatory responses. Thus, the use of PPAR-⍺ agonists, such as fibrates (fenofibrate and choline-fenofibrate), currently used in dyslipidemia treatment, could represent an interesting therapeutic approach in PIPN. EXPERIMENTAL APPROACH Our studies tested the efficacy of fenofibrate (150 mg/kg, daily, i.p.) and choline fenofibrate (60 mg/kg daily, p.o.) in reversing and preventing the development of PIPN (paclitaxel: 8 mg/kg, i.p., every other day for 4 days) in male and female C57BL/6J mice. Mechanical and cold hypersensitivity, conditioned place preference, sensory nerve action potential (SNAP), as well as the expression of PPAR-⍺, TNF-⍺, IL-1β and IL-6 mRNA were evaluated. KEY RESULTS While fenofibrate treatment partially reversed and prevented the development of mechanical hypersensitivity, this was completely reversed and prevented by choline-fenofibrate. Both fibrates were able to completely reverse and prevent cold hypersensitivity induced by paclitaxel. The reduction of SNAP amplitude induced by paclitaxel was also reversed by both fenofibrate and choline-fenofibrate. Our results indicate that suppression of paclitaxel-induced hypersensitivity by fibrates involves the regulation of PPAR-⍺ expression and decrease neuroinflammation in DRG. Finally, the co-treatment of Paclitaxel and fenofibric acid (fibrates active metabolite) was tested on different cancer cell lines, no decrease in the antitumoral effect of paclitaxel was observed. CONCLUSIONS AND IMPLICATIONS Taken together, our results show for the first time the therapeutic potential (prevention and reversal) of fibrates in PIPN and opens to a potential pharmacological repurposing of these drugs.
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Affiliation(s)
- Martial CAILLAUD
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA.,Corresponding authors:,
| | - Nipa H. PATEL
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - Alyssa WHITE
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - Mackinsey WOOD
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - Katherine M. Contreras
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - Wisam TOMA
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - Yasmin Alkhlaif
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - Jane L. ROBERTS
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - Tammy H. Tran
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - Asti B. JACKSON
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - Justin POKLIS
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - David A. GEWIRTZ
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA
| | - M. Imad DAMAJ
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA.,Translational Research Initiative for Pain and Neuropathy, Virginia Commonwealth University, USA.,Corresponding authors:,
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Gu C. Rapid and Reversible Development of Axonal Varicosities: A New Form of Neural Plasticity. Front Mol Neurosci 2021; 14:610857. [PMID: 33613192 PMCID: PMC7886671 DOI: 10.3389/fnmol.2021.610857] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2020] [Accepted: 01/05/2021] [Indexed: 12/11/2022] Open
Abstract
Axonal varicosities are enlarged, heterogeneous structures along axonal shafts, profoundly affecting axonal conduction and synaptic transmission. They represent a key pathological feature believed to develop via slow accumulation of axonal damage that occurs during irreversible degeneration, for example in mild traumatic brain injury (mTBI), Alzheimer's and Parkinson's diseases, and multiple sclerosis. Here this review first discusses recent in vitro results showing that axonal varicosities can be rapidly and reversibly induced by mechanical stress in cultured primary neurons from the central nervous system (CNS). This notion is further supported by in vivo studies revealing the induction of axonal varicosities across various brain regions in different mTBI mouse models, as a prominent feature of axonal pathology. Limited progress in understanding intrinsic and extrinsic regulatory mechanisms of axonal varicosity induction and development is further highlighted. Rapid and reversible formation of axonal varicosities likely plays a key role in CNS neuron mechanosensation and is a new form of neural plasticity. Future investigation in this emerging research field may reveal how to reverse axonal injury, contributing to the development of new strategies for treating brain injuries and related neurodegenerative diseases.
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Affiliation(s)
- Chen Gu
- Department of Biological Chemistry and Pharmacology, The Ohio State University, Columbus, OH, United States
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19
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Caillaud M, Patel NH, Toma W, White A, Thompson D, Mann J, Tran TH, Roberts JL, Poklis JL, Bigbee JW, Fang X, Gewirtz DA, Damaj MI. A Fenofibrate Diet Prevents Paclitaxel-Induced Peripheral Neuropathy in Mice. Cancers (Basel) 2020; 13:cancers13010069. [PMID: 33383736 PMCID: PMC7795224 DOI: 10.3390/cancers13010069] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/02/2020] [Revised: 12/19/2020] [Accepted: 12/21/2020] [Indexed: 12/16/2022] Open
Abstract
Simple Summary Paclitaxel, a drug used in the treatment of malignancies such as lung, ovarian and breast cancer, often produces severe side effects, among which is peripheral neuropathy. This neuropathy involves diffuse or localized pain, notably burning pain, cold and mechanical hyperexcitability. Recently, fenofibrate, a Food and Drug Administration (FDA)-approved drug for the treatment of dyslipidemia, has been shown to reduce the severity of symptoms in other forms of peripheral neuropathy. In the current work, we tested whether fenofibrate could reverse mechanical and cold hypersensitivity and improve motivation and the reduction in nerve conduction in a mouse model of paclitaxel-induced neuropathy. Our behavioral, histological and molecular assessments indicate that fenofibrate prevents the development of paclitaxel-induced neuropathy. Taken together, our studies support the therapeutic potential of fenofibrate in the prevention of paclitaxel-induced neuropathy and suggest the possible repurposing of this drug for this purpose in the clinic. Abstract Background: Paclitaxel-induced peripheral neuropathy (PIPN) is a major adverse effect of this chemotherapeutic agent that is used in the treatment of a number of solid malignancies. PIPN leads notably to burning pain, cold and mechanical allodynia. PIPN is thought to be a consequence of alterations of mitochondrial function, hyperexcitability of neurons, nerve fiber loss, oxidative stress and neuroinflammation in dorsal root ganglia (DRG) and spinal cord (SC). Therefore, reducing neuroinflammation could potentially attenuate neuropathy symptoms. Peroxisome proliferator-activated receptor-α (PPAR-α) nuclear receptors that modulate inflammatory responses can be targeted by non-selective agonists, such as fenofibrate, which is used in the treatment of dyslipidemia. Methods: Our studies tested the efficacy of a fenofibrate diet (0.2% and 0.4%) in preventing the development of PIPN. Paclitaxel (8 mg/kg) was administered via 4 intraperitoneal (i.p.) injections in C57BL/6J mice (both male and female). Mechanical and cold hypersensitivity, wheel running activity, sensory nerve action potential (SNAP), sciatic nerve histology, intra-epidermal fibers, as well as the expression of PPAR-α and neuroinflammation were evaluated in DRG and SC. Results: Fenofibrate in the diet partially prevented the development of mechanical hypersensitivity but completely prevented cold hypersensitivity and the decrease in wheel running activity induced by paclitaxel. The reduction in SNAP amplitude induced by paclitaxel was also prevented by fenofibrate. Our results indicate that suppression of paclitaxel-induced pain by fenofibrate involves the regulation of PPAR-α expression through reduction in neuroinflammation. Finally, co-administration of paclitaxel and the active metabolite of fenofibrate (fenofibric acid) did not interfere with the suppression of tumor cell growth or clonogenicity by paclitaxel in ovarian and breast cancer cell lines. Conclusions: Taken together, our results show the therapeutic potential of fenofibrate in the prevention of PIPN development.
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Affiliation(s)
- Martial Caillaud
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23284, USA; (W.T.); (A.W.); (D.T.); (J.M.); (J.L.R.); (J.L.P.)
- Correspondence: (M.C.); (M.I.D.)
| | - Nipa H. Patel
- Departments of Pharmacology and Toxicology and Medicine and Massey Cancer Center, Virginia Commonwealth University, Massey Cancer Center, Richmond, VA 23284, USA; (N.H.P.); (T.H.T.); (D.A.G.)
| | - Wisam Toma
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23284, USA; (W.T.); (A.W.); (D.T.); (J.M.); (J.L.R.); (J.L.P.)
| | - Alyssa White
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23284, USA; (W.T.); (A.W.); (D.T.); (J.M.); (J.L.R.); (J.L.P.)
| | - Danielle Thompson
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23284, USA; (W.T.); (A.W.); (D.T.); (J.M.); (J.L.R.); (J.L.P.)
| | - Jared Mann
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23284, USA; (W.T.); (A.W.); (D.T.); (J.M.); (J.L.R.); (J.L.P.)
| | - Tammy H. Tran
- Departments of Pharmacology and Toxicology and Medicine and Massey Cancer Center, Virginia Commonwealth University, Massey Cancer Center, Richmond, VA 23284, USA; (N.H.P.); (T.H.T.); (D.A.G.)
| | - Jane L. Roberts
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23284, USA; (W.T.); (A.W.); (D.T.); (J.M.); (J.L.R.); (J.L.P.)
| | - Justin L. Poklis
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23284, USA; (W.T.); (A.W.); (D.T.); (J.M.); (J.L.R.); (J.L.P.)
| | - John W. Bigbee
- Department of Anatomy and Neurobiology, School of Medicine, Virginia Commonwealth University, Richmond, VA 23284, USA;
| | - Xianjun Fang
- Department of Biochemistry & Molecular Biology, School of Medicine, Virginia Commonwealth University, Richmond, VA 23284, USA;
| | - David A. Gewirtz
- Departments of Pharmacology and Toxicology and Medicine and Massey Cancer Center, Virginia Commonwealth University, Massey Cancer Center, Richmond, VA 23284, USA; (N.H.P.); (T.H.T.); (D.A.G.)
| | - M. Imad Damaj
- Department of Pharmacology and Toxicology and Translational Research Initiative for Pain and Neuropathy, Medical College of Virginia Campus, Virginia Commonwealth University, Richmond, VA 23284, USA; (W.T.); (A.W.); (D.T.); (J.M.); (J.L.R.); (J.L.P.)
- Correspondence: (M.C.); (M.I.D.)
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Korimová A, Dubový P. N-Formylated Peptide Induces Increased Expression of Both Formyl Peptide Receptor 2 (Fpr2) and Toll-Like Receptor 9 (TLR9) in Schwannoma Cells-An In Vitro Model for Early Inflammatory Profiling of Schwann Cells. Cells 2020; 9:cells9122661. [PMID: 33322305 PMCID: PMC7763069 DOI: 10.3390/cells9122661] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/19/2020] [Revised: 12/09/2020] [Accepted: 12/09/2020] [Indexed: 12/12/2022] Open
Abstract
Following nerve injury, disintegrated axonal mitochondria distal to the injury site release mitochondrial formylated peptides and DNA that can induce activation and inflammatory profiling of Schwann cells via formyl peptide receptor 2 (Fpr2) and toll-like receptor 9 (TLR9), respectively. We studied RT4 schwannoma cells to investigate the regulation of Fpr2 and TLR9 after stimulation with fMLF as a prototypical formylated peptide. RT4 cells were treated with fMLF at various concentrations and times with and without pretreatment with inhibitors (chloroquine for activated TLR9, PBP10 for Fpr2). Western blots of Fpr2, TLR9, p-p38, p-NFκB, and IL-6 were compared in relation to inflammatory profiling of RT4 cells and chemokine receptors (CCR2, CXCR4) as potential co-receptors of Fpr2. fMLF stimulation upregulated Fpr2 in RT4 cells at low concentrations (10 nM and 100 nM) but higher concentrations were required (10 µM and 50 µM) when the cells were pretreated with an activated TLR9 inhibitor. Moreover, the higher concentrations of fMLF could modulate TLR9 and inflammatory markers. Upregulation of Fpr2 triggered by 10 nM and 100 nM fMLF coincided with higher levels of chemokine receptors (CCR2, CXCR4) and PKCβ. Treating RT4 cells with fMLF, as an in vitro model of Schwann cells, uncovered Schwann cells’ complex responses to molecular patterns of release from injured axonal mitochondria.
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Fight fire with fire: Neurobiology of capsaicin-induced analgesia for chronic pain. Pharmacol Ther 2020; 220:107743. [PMID: 33181192 DOI: 10.1016/j.pharmthera.2020.107743] [Citation(s) in RCA: 43] [Impact Index Per Article: 10.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2020] [Accepted: 11/04/2020] [Indexed: 12/12/2022]
Abstract
Capsaicin, the pungent ingredient in chili peppers, produces intense burning pain in humans. Capsaicin selectively activates the transient receptor potential vanilloid 1 (TRPV1), which is enriched in nociceptive primary afferents, and underpins the mechanism for capsaicin-induced burning pain. Paradoxically, capsaicin has long been used as an analgesic. The development of topical patches and injectable formulations containing capsaicin has led to application in clinical settings to treat chronic pain conditions, such as neuropathic pain and the potential to treat osteoarthritis. More detailed determination of the neurobiological mechanisms of capsaicin-induced analgesia should provide the logical rationale for capsaicin therapy and help to overcome the treatment's limitations, which include individual differences in treatment outcome and procedural discomfort. Low concentrations of capsaicin induce short-term defunctionalization of nociceptor terminals. This phenomenon is reversible within hours and, hence, likely does not account for the clinical benefit. By contrast, high concentrations of capsaicin lead to long-term defunctionalization mediated by the ablation of TRPV1-expressing afferent terminals, resulting in long-lasting analgesia persisting for several months. Recent studies have shown that capsaicin-induced Ca2+/calpain-mediated ablation of axonal terminals is necessary to produce long-lasting analgesia in a mouse model of neuropathic pain. In combination with calpain, axonal mitochondrial dysfunction and microtubule disorganization may also contribute to the longer-term effects of capsaicin. The analgesic effects subside over time in association with the regeneration of the ablated afferent terminals. Further determination of the neurobiological mechanisms of capsaicin-induced analgesia should lead to more efficacious non-opioidergic analgesic options with fewer adverse side effects.
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Jin J, Chen N, Pan H, Xie W, Xu H, Lei S, Guo Z, Ding R, He Y, Gao J. Triclosan induces ROS-dependent cell death and autophagy in A375 melanoma cells. Oncol Lett 2020; 20:73. [PMID: 32863906 PMCID: PMC7436935 DOI: 10.3892/ol.2020.11934] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2019] [Accepted: 06/23/2020] [Indexed: 12/29/2022] Open
Abstract
Melanoma is a common type of cutaneous tumor, but current drug treatments do not satisfy clinical practice requirements. At present, mitochondrial uncoupling is an effective antitumor treatment. Triclosan, a common antimicrobial, also acts as a mitochondrial uncoupler. The aims of the present study were to investigate the effects of triclosan on melanoma cells and the underlying mechanisms. Mitochondrial membrane potential (MMP), mitochondrial morphology, mitochondrial reactive oxygen species (mito-ROS), intracellular superoxide anion and [Ca2+]i were measured using confocal microscopy. It was found that triclosan application was associated with decreased A375 cell viability in a dose- and time-dependent manner and these effects may have cell specificity. Furthermore, triclosan induced MMP depolarization, ATP content decrease, mito-ROS and [Ca2+]i level increases, excessive mitochondrial fission, AMP-activated protein kinase (AMPK) activation and STAT3 inhibition. Moreover, these aforementioned effects were reversed by acetylcysteine treatment. Triclosan acute treatment also induced mitochondrial swelling, which was reversed after AMPK-knockdown associated with [Ca2+]i overload. Cell death was caused by STAT3 inhibition but not AMPK activation. Moreover, triclosan induced autophagy via the ROS/AMPK/p62/microtubule-associated protein 1A/1B-light chain 3 (LC3) signaling pathway, which may serve a role in feedback protection. Collectively, the present results suggested that triclosan increased mito-ROS production in melanoma cells, following induced cell death via the STAT3/Bcl-2 pathway and autophagy via the AMPK/p62/LC3 pathway.
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Affiliation(s)
- Jing Jin
- Department of Urology, The Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China
| | - Naiwen Chen
- Department of Urology, The Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China.,Department of Surgety, The Second Clinical Medical College of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Huan Pan
- Department of Central Laboratory, The Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China
| | - Wenhua Xie
- Department of Urology, The Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China
| | - Hong Xu
- Department of Urology, The Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China.,Department of Surgety, The Second Clinical Medical College of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Siyu Lei
- Department of Urology, The Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China.,Department of Surgety, The Second Clinical Medical College of Zhejiang Chinese Medical University, Hangzhou, Zhejiang 310053, P.R. China
| | - Zhiqin Guo
- Department of Pathology, The Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China
| | - Renye Ding
- Department of Clinical Laboratory, The Affiliated Hospital of Jiaxing University, Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China
| | - Yi He
- Department of Urology, The Affiliated Hospital of Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China
| | - Jinlai Gao
- Department of Pharmacology, College of Medical, Jiaxing University, Jiaxing, Zhejiang 314001, P.R. China
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23
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Tsialtas I, Gorgogietas VA, Michalopoulou M, Komninou A, Liakou E, Georgantopoulos A, Kalousi FD, Karra AG, Protopapa E, Psarra AMG. Neurotoxic effects of aluminum are associated with its interference with estrogen receptors signaling. Neurotoxicology 2020; 77:114-126. [PMID: 31945389 DOI: 10.1016/j.neuro.2020.01.004] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2019] [Revised: 01/10/2020] [Accepted: 01/12/2020] [Indexed: 12/20/2022]
Abstract
Aluminum compounds have been observed in various brain regions, and their accumulation has been associated with many neurodegenerative disorders. Neurotoxic effects of aluminum are attributed to reactive oxygen species generation, induction of apoptosis and inflammatory reactions activation. Metalloestrogen activity of aluminum has also been linked to breast cancer progression and metastasis. In this study, taking into account the anti-apoptotic and anti-oxidant activities of estrogens in neuronal cells, which are mediated by estrogen receptors, the possible estrogenic activity of aluminum in SH-SY5Y neuroblastoma cells was studied. Our results showed that aluminum in the form of aluminum chlorohydrate (ACH) exhibited no effect on estrogen receptors transcriptional activation, and differential effect on estrogen receptor alpha (ERα) and estrogen receptor beta (ERβ) protein levels. ACH caused reduction in ERβ protein levels, and increase in its mitochondrial localization. ACH-induced reduction in ERβ protein level may be linked, at least in part, to the ACH-induced increase in ERα protein level. This statement is based on our observations showing aluminum-induced reduction in the E2-induced increase in ERα S118 phosphorylation, in MCF-7 and SH-SH5Y cells. Phosphorylation at S118 residue is known to be associated with inhibition of the ubiquitin-induced proteolytic degradation of ERα, leading to its accumulation. Since it is known that ERα negatively regulate ERβ expression, increase in ERα, may contribute to reduction in ERβ levels and subsequent weakening of its anti-apoptotic and anti-oxidant activity, justified by the observed reduction in procaspase 9, mitochondrial cytochrome c, Bcl-2, Bcl-xL and mitochondrial thioredoxin protein level, as well as by the increase in proapoptotic BAX level, in ACH treated SH-SY5Y cells. In addition, increase in mitochondrial ERβ localization may also trigger mitochondrial metabolism, suppress biosynthetic process of gluconeogenesis, as indicated by the observed reduction in the phosphoenolpyruvate carboxykinase protein level, and eventually lead to increase in reactive oxygen species (ROS) generation, known to be implicated in aluminum induced neurodegeneration. This statement was verified by the observed ACH-induced increase in ERβ mitochondrial localization, induction of the mitochondrial membrane depolarization and increase in ROS production, in neuronal-like differentiated SH-SY5Y cells.
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Affiliation(s)
- Ioannis Tsialtas
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Vyron A Gorgogietas
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Maria Michalopoulou
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Aggeliki Komninou
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Eleni Liakou
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | | | - Foteini D Kalousi
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Aikaterini G Karra
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece
| | - Evagelia Protopapa
- Department of Aesthetics and Cosmetology, Faculty of Health & Caring Professions, University of West Attica, Egaleo, Greece
| | - Anna-Maria G Psarra
- Department of Biochemistry and Biotechnology, University of Thessaly, Larissa, Greece.
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24
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Courson JA, Smith I, Do T, Landry PT, Hargrave A, Behzad AR, Hanlon SD, Rumbaut RE, Smith CW, Burns AR. Serial block-face scanning electron microscopy reveals neuronal-epithelial cell fusion in the mouse cornea. PLoS One 2019; 14:e0224434. [PMID: 31721785 PMCID: PMC6853292 DOI: 10.1371/journal.pone.0224434] [Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2019] [Accepted: 10/14/2019] [Indexed: 11/28/2022] Open
Abstract
The cornea is the most highly innervated tissue in the body. It is generally accepted that corneal stromal nerves penetrate the epithelial basal lamina giving rise to intra-epithelial nerves. During the course of a study wherein we imaged corneal nerves in mice, we observed a novel neuronal-epithelial cell interaction whereby nerves approaching the epithelium in the cornea fused with basal epithelial cells, such that their plasma membranes were continuous and the neuronal axoplasm freely abutted the epithelial cytoplasm. In this study we sought to determine the frequency, distribution, and morphological profile of neuronal-epithelial cell fusion events within the cornea. Serial electron microscopy images were obtained from the anterior stroma in the paralimbus and central cornea of 8–10 week old C57BL/6J mice. We found evidence of a novel alternative behavior involving a neuronal-epithelial interaction whereby 42.8% of central corneal nerve bundles approaching the epithelium contain axons that fuse with basal epithelial cells. The average surface-to-volume ratio of a penetrating nerve was 3.32, while the average fusing nerve was smaller at 1.39 (p ≤ 0.0001). Despite this, both neuronal-epithelial cell interactions involve similarly sized discontinuities in the basal lamina. In order to verify the plasma membrane continuity between fused neurons and epithelial cells we used the lipophilic membrane tracer DiI. The majority of corneal nerves were labeled with DiI after application to the trigeminal ganglion and, consistent with our ultrastructural observations, fusion sites recognized as DiI-labeled basal epithelial cells were located at points of stromal nerve termination. These studies provide evidence that neuronal-epithelial cell fusion is a cell-cell interaction that occurs primarily in the central cornea, and fusing nerve bundles are morphologically distinct from penetrating nerve bundles. This is, to our knowledge, the first description of neuronal-epithelial cell fusion in the literature adding a new level of complexity to the current understanding of corneal innervation.
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Affiliation(s)
- Justin A. Courson
- University of Houston, College of Optometry, Houston, TX, United States of America
- * E-mail:
| | - Ian Smith
- University of Houston, College of Optometry, Houston, TX, United States of America
| | - Thao Do
- University of Houston, College of Optometry, Houston, TX, United States of America
| | - Paul T. Landry
- University of Houston, College of Optometry, Houston, TX, United States of America
| | - Aubrey Hargrave
- University of Houston, College of Optometry, Houston, TX, United States of America
| | - Ali R. Behzad
- King Abdullah University of Science and Technology (KAUST), Core Labs, Thuwal, Saudi Arabia
| | - Sam D. Hanlon
- University of Houston, College of Optometry, Houston, TX, United States of America
| | - Rolando E. Rumbaut
- Baylor College of Medicine, Children’s Nutrition Center, Houston, TX, United States of America
- Center for Translational Research on Inflammatory Diseases (CTRID), Michael E. DeBakey Veterans Affairs Medical Center, Houston, TX, United States of America
| | - C. Wayne Smith
- Baylor College of Medicine, Children’s Nutrition Center, Houston, TX, United States of America
| | - Alan R. Burns
- University of Houston, College of Optometry, Houston, TX, United States of America
- Baylor College of Medicine, Children’s Nutrition Center, Houston, TX, United States of America
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25
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Axonal degeneration in an in vitro model of ischemic white matter injury. Neurobiol Dis 2019; 134:104672. [PMID: 31707117 DOI: 10.1016/j.nbd.2019.104672] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2019] [Revised: 10/18/2019] [Accepted: 11/06/2019] [Indexed: 01/15/2023] Open
Abstract
Ischemic white matter injuries underlie cognitive decline in the elderly and vascular dementia. Ischemia in the subcortical white matter is caused by chronic reduction of blood flow due to narrowing of small arterioles. However, it remains unclear how chronic ischemia leads to white matter pathology. We aimed to develop an in vitro model of ischemic white matter injury using organotypic slice cultures. Cultured cerebellar slices preserved fully myelinated white matter tracts that were amenable to chronic hypoxic insult. Prolonged hypoxia caused progressive morphological evidence of axonal degeneration with focal constrictions and swellings. In contrast, myelin sheaths and oligodendrocytes exhibited remarkable resilience to hypoxia. The cytoskeletal degradation of axons was accompanied by mitochondrial shortening and lysosomal activation. Multiple pharmacological manipulations revealed that the AMPA glutamate receptor, calpain proteolysis, and lysosomal proteases were independently implicated in hypoxia-induced axonal degeneration in our model. Thus, our in vitro model would be a novel experimental system to explore molecular mechanisms of ischemic white matter injury. Furthermore, we verified that the in vitro assay could be successfully utilized to screen for molecules that can ameliorate hypoxia/ischemia-induced axonal degeneration.
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26
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Kline RA, Dissanayake KN, Hurtado ML, Martínez NW, Ahl A, Mole AJ, Lamont DJ, Court FA, Ribchester RR, Wishart TM, Murray LM. Altered mitochondrial bioenergetics are responsible for the delay in Wallerian degeneration observed in neonatal mice. Neurobiol Dis 2019; 130:104496. [PMID: 31176719 PMCID: PMC6704473 DOI: 10.1016/j.nbd.2019.104496] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2019] [Revised: 04/26/2019] [Accepted: 06/05/2019] [Indexed: 01/10/2023] Open
Abstract
Neurodegenerative and neuromuscular disorders can manifest throughout the lifespan of an individual, from infant to elderly individuals. Axonal and synaptic degeneration are early and critical elements of nearly all human neurodegenerative diseases and neural injury, however the molecular mechanisms which regulate this process are yet to be fully elucidated. Furthermore, how the molecular mechanisms governing degeneration are impacted by the age of the individual is poorly understood. Interestingly, in mice which are under 3 weeks of age, the degeneration of axons and synapses following hypoxic or traumatic injury is significantly slower. This process, known as Wallerian degeneration (WD), is a molecularly and morphologically distinct subtype of neurodegeneration by which axons and synapses undergo distinct fragmentation and death following a range of stimuli. In this study, we first use an ex-vivo model of axon injury to confirm the significant delay in WD in neonatal mice. We apply tandem mass-tagging quantitative proteomics to profile both nerve and muscle between P12 and P24 inclusive. Application of unbiased in silico workflows to relevant protein identifications highlights a steady elevation in oxidative phosphorylation cascades corresponding to the accelerated degeneration rate. We demonstrate that inhibition of Complex I prevents the axotomy-induced rise in reactive oxygen species and protects axons following injury. Furthermore, we reveal that pharmacological activation of oxidative phosphorylation significantly accelerates degeneration at the neuromuscular junction in neonatal mice. In summary, we reveal dramatic changes in the neuromuscular proteome during post-natal maturation of the neuromuscular system, and demonstrate that endogenous dynamics in mitochondrial bioenergetics during this time window have a functional impact upon regulating the stability of the neuromuscular system.
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Affiliation(s)
- Rachel A Kline
- Centre for Discovery Brain Science, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, UK; Euan McDonald Centre for Motor Neuron Disease Research, University of Edinburgh, UK; The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, EH25 9RG, UK
| | - Kosala N Dissanayake
- Euan McDonald Centre for Motor Neuron Disease Research, University of Edinburgh, UK; Centre for Cognitive and Neural Systems, University of Edinburgh, 1 George Square, Edinburgh EH8 9JZ, UK
| | - Maica Llavero Hurtado
- Euan McDonald Centre for Motor Neuron Disease Research, University of Edinburgh, UK; The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, EH25 9RG, UK
| | - Nicolás W Martínez
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile
| | - Alexander Ahl
- Centre for Discovery Brain Science, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, UK
| | - Alannah J Mole
- Centre for Discovery Brain Science, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, UK; Euan McDonald Centre for Motor Neuron Disease Research, University of Edinburgh, UK
| | - Douglas J Lamont
- Fingerprints Proteomics Facility, Dundee University, Dundee DD1 4HN, United Kingdom
| | - Felipe A Court
- Center for Integrative Biology, Faculty of Sciences, Universidad Mayor, Santiago, Chile; Geroscience Center for Brain Health and Metabolism, Santiago, Chile; The Buck Institute for Research on Aging, Novato, CA, United States
| | - Richard R Ribchester
- Euan McDonald Centre for Motor Neuron Disease Research, University of Edinburgh, UK; Centre for Cognitive and Neural Systems, University of Edinburgh, 1 George Square, Edinburgh EH8 9JZ, UK
| | - Thomas M Wishart
- Euan McDonald Centre for Motor Neuron Disease Research, University of Edinburgh, UK; The Roslin Institute and Royal (Dick) School of Veterinary Studies, University of Edinburgh, Easter Bush, EH25 9RG, UK
| | - Lyndsay M Murray
- Centre for Discovery Brain Science, University of Edinburgh, Hugh Robson Building, Edinburgh EH8 9XD, UK; Euan McDonald Centre for Motor Neuron Disease Research, University of Edinburgh, UK.
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27
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Llobet Rosell A, Neukomm LJ. Axon death signalling in Wallerian degeneration among species and in disease. Open Biol 2019; 9:190118. [PMID: 31455157 PMCID: PMC6731592 DOI: 10.1098/rsob.190118] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Axon loss is a shared feature of nervous systems being challenged in neurological disease, by chemotherapy or mechanical force. Axons take up the vast majority of the neuronal volume, thus numerous axonal intrinsic and glial extrinsic support mechanisms have evolved to promote lifelong axonal survival. Impaired support leads to axon degeneration, yet underlying intrinsic signalling cascades actively promoting the disassembly of axons remain poorly understood in any context, making the development to attenuate axon degeneration challenging. Wallerian degeneration serves as a simple model to study how axons undergo injury-induced axon degeneration (axon death). Severed axons actively execute their own destruction through an evolutionarily conserved axon death signalling cascade. This pathway is also activated in the absence of injury in diseased and challenged nervous systems. Gaining insights into mechanisms underlying axon death signalling could therefore help to define targets to block axon loss. Herein, we summarize features of axon death at the molecular and subcellular level. Recently identified and characterized mediators of axon death signalling are comprehensively discussed in detail, and commonalities and differences across species highlighted. We conclude with a summary of engaged axon death signalling in humans and animal models of neurological conditions. Thus, gaining mechanistic insights into axon death signalling broadens our understanding beyond a simple injury model. It harbours the potential to define targets for therapeutic intervention in a broad range of human axonopathies.
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Affiliation(s)
- Arnau Llobet Rosell
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, VD, Switzerland
| | - Lukas J Neukomm
- Department of Fundamental Neurosciences, University of Lausanne, Rue du Bugnon 9, 1005 Lausanne, VD, Switzerland
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28
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Axonal Degeneration Is Mediated by Necroptosis Activation. J Neurosci 2019; 39:3832-3844. [PMID: 30850513 DOI: 10.1523/jneurosci.0881-18.2019] [Citation(s) in RCA: 34] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2018] [Revised: 02/01/2019] [Accepted: 02/14/2019] [Indexed: 01/22/2023] Open
Abstract
Axonal degeneration, which contributes to functional impairment in several disorders of the nervous system, is an important target for neuroprotection. Several individual factors and subcellular events have been implicated in axonal degeneration, but researchers have so far been unable to identify an integrative signaling pathway activating this self-destructive process. Through pharmacological and genetic approaches, we tested whether necroptosis, a regulated cell-death mechanism implicated in the pathogenesis of several neurodegenerative diseases, is involved in axonal degeneration. Pharmacological inhibition of the necroptotic kinase RIPK1 using necrostatin-1 strongly delayed axonal degeneration in the peripheral nervous system and CNS of wild-type mice of either sex and protected in vitro sensory axons from degeneration after mechanical and toxic insults. These effects were also observed after genetic knock-down of RIPK3, a second key regulator of necroptosis, and the downstream effector MLKL (Mixed Lineage Kinase Domain-Like). RIPK1 inhibition prevented mitochondrial fragmentation in vitro and in vivo, a typical feature of necrotic death, and inhibition of mitochondrial fission by Mdivi also resulted in reduced axonal loss in damaged nerves. Furthermore, electrophysiological analysis demonstrated that inhibition of necroptosis delays not only the morphological degeneration of axons, but also the loss of their electrophysiological function after nerve injury. Activation of the necroptotic pathway early during injury-induced axonal degeneration was made evident by increased phosphorylation of the downstream effector MLKL. Our results demonstrate that axonal degeneration proceeds by necroptosis, thus defining a novel mechanistic framework in the axonal degenerative cascade for therapeutic interventions in a wide variety of conditions that lead to neuronal loss and functional impairment.SIGNIFICANCE STATEMENT We show that axonal degeneration triggered by diverse stimuli is mediated by the activation of the necroptotic programmed cell-death program by a cell-autonomous mechanism. This work represents a critical advance for the field since it identifies a defined degenerative pathway involved in axonal degeneration in both the peripheral nervous system and the CNS, a process that has been proposed as an early event in several neurodegenerative conditions and a major contributor to neuronal death. The identification of necroptosis as a key mechanism for axonal degeneration is an important step toward the development of novel therapeutic strategies for nervous-system disorders, particularly those related to chemotherapy-induced peripheral neuropathies or CNS diseases in which axonal degeneration is a common factor.
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29
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Kounakis K, Tavernarakis N. The Cytoskeleton as a Modulator of Aging and Neurodegeneration. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1178:227-245. [PMID: 31493230 DOI: 10.1007/978-3-030-25650-0_12] [Citation(s) in RCA: 27] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
The cytoskeleton consists of filamentous protein polymers that form organized structures, contributing to a multitude of cell life aspects. It includes three types of polymers: the actin microfilaments, the microtubules and the intermediate filaments. Decades of research have implicated the cytoskeleton in processes that regulate cellular and organismal aging, as well as neurodegeneration associated with injury or neurodegenerative disease, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, Amyotrophic Lateral Sclerosis, or Charcot Marie Tooth disease. Here, we provide a brief overview of cytoskeletal structure and function, and discuss experimental evidence linking cytoskeletal function and dynamics with aging and neurodegeneration.
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Affiliation(s)
- Konstantinos Kounakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece.,Department of Basic Sciences, Medical School, University of Crete, Heraklion, Greece
| | - Nektarios Tavernarakis
- Institute of Molecular Biology and Biotechnology, Foundation for Research and Technology-Hellas, Heraklion, Greece. .,Department of Basic Sciences, Medical School, University of Crete, Heraklion, Greece.
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30
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Korimová A, Klusáková I, Hradilová-Svíženská I, Kohoutková M, Joukal M, Dubový P. Mitochondrial Damage-Associated Molecular Patterns of Injured Axons Induce Outgrowth of Schwann Cell Processes. Front Cell Neurosci 2018; 12:457. [PMID: 30542268 PMCID: PMC6277938 DOI: 10.3389/fncel.2018.00457] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/19/2018] [Accepted: 11/12/2018] [Indexed: 01/13/2023] Open
Abstract
Activated Schwann cells put out cytoplasmic processes that play a significant role in cell migration and axon regeneration. Following nerve injury, axonal mitochondria release mitochondrial damage-associated molecular patterns (mtDAMPs), including formylated peptides and mitochondrial DNA (mtDNA). We hypothesize that mtDAMPs released from disintegrated axonal mitochondria may stimulate Schwann cells to put out cytoplasmic processes. We investigated RT4-D6P2T schwannoma cells (RT4) in vitro treated with N-formyl-L-methionyl-L-leucyl-phenylalanine (fMLP) or cytosine-phospho-guanine oligodeoxynucleotide (CpG ODN) for 1, 6 and 24 h. We also used immunohistochemical detection to monitor the expression of formylpeptide receptor 2 (FPR2) and toll-like receptor 9 (TLR9), the canonical receptors for formylated peptides and mtDNA, in RT4 cells and Schwann cells distal to nerve injury. RT4 cells treated with fMLP put out a significantly higher number of cytoplasmic processes compared to control cells. Preincubation with PBP10, a selective inhibitor of FPR2 resulted in a significant reduction of cytoplasmic process outgrowth. A significantly higher number of cytoplasmic processes was also found after treatment with CpG ODN compared to control cells. Pretreatment with inhibitory ODN (INH ODN) resulted in a reduced number of cytoplasmic processes after subsequent treatment with CpG ODN only at 6 h, but 1 and 24 h treatment with CpG ODN demonstrated an additive effect of INH ODN on the development of cytoplasmic processes. Immunohistochemistry and western blot detected increased levels of tyrosine-phosphorylated paxillin in RT4 cells associated with cytoplasmic process outgrowth after fMLP or CpG ODN treatment. We found increased immunofluorescence of FPR2 and TLR9 in RT4 cells treated with fMLP or CpG ODN as well as in activated Schwann cells distal to the nerve injury. In addition, activated Schwann cells displayed FPR2 and TLR9 immunostaining close to GAP43-immunopositive regenerated axons and their growth cones after nerve crush. Increased FPR2 and TLR9 immunoreaction was associated with activation of p38 and NFkB, respectively. Surprisingly, the growth cones displayed also FPR2 and TLR9 immunostaining. These results present the first evidence that potential mtDAMPs may play a key role in the induction of Schwann cell processes. This reaction of Schwann cells can be mediated via FPR2 and TLR9 that are canonical receptors for formylated peptides and mtDNA. The possible role for FPR2 and TLR9 in growth cones is also discussed.
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Affiliation(s)
- Andrea Korimová
- Department of Anatomy, Division of Neuroanatomy, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Ilona Klusáková
- Department of Anatomy, Division of Neuroanatomy, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Ivana Hradilová-Svíženská
- Department of Anatomy, Division of Neuroanatomy, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Marcela Kohoutková
- Department of Anatomy, Division of Neuroanatomy, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Marek Joukal
- Department of Anatomy, Division of Neuroanatomy, Faculty of Medicine, Masaryk University, Brno, Czechia
| | - Petr Dubový
- Department of Anatomy, Division of Neuroanatomy, Faculty of Medicine, Masaryk University, Brno, Czechia
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Phosphatidylserine is a marker for axonal debris engulfment but its exposure can be decoupled from degeneration. Cell Death Dis 2018; 9:1116. [PMID: 30389906 PMCID: PMC6214901 DOI: 10.1038/s41419-018-1155-z] [Citation(s) in RCA: 27] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/16/2018] [Revised: 09/25/2018] [Accepted: 10/08/2018] [Indexed: 02/08/2023]
Abstract
Apoptotic cells expose Phosphatidylserine (PS), that serves as an “eat me” signal for engulfing cells. Previous studies have shown that PS also marks degenerating axonsduring developmental pruning or in response to insults (Wallerian degeneration), but the pathways that control PS exposure on degenerating axons are largely unknown. Here, we used a series of in vitro assays to systematically explore the regulation of PS exposure during axonal degeneration. Our results show that PS exposure is regulated by the upstream activators of axonal pruning and Wallerian degeneration. However, our investigation of signaling further downstream revealed divergence between axon degeneration and PS exposure. Importantly, elevation of the axonal energetic status hindered PS exposure, while inhibition of mitochondrial activity caused PS exposure, without degeneration. Overall, our results suggest that the levels of PS on the outer axonal membrane can be dissociated from the degeneration process and that the axonal energetic status plays a key role in the regulation of PS exposure.
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Abstract
Nicotinic acid and nicotinamide, collectively referred to as niacin, are nutritional precursors of the bioactive molecules nicotinamide adenine dinucleotide (NAD) and nicotinamide adenine dinucleotide phosphate (NADP). NAD and NADP are important cofactors for most cellular redox reactions, and as such are essential to maintain cellular metabolism and respiration. NAD also serves as a cosubstrate for a large number of ADP-ribosylation enzymes with varied functions. Among the NAD-consuming enzymes identified to date are important genetic and epigenetic regulators, e.g., poly(ADP-ribose)polymerases and sirtuins. There is rapidly growing knowledge of the close connection between dietary niacin intake, NAD(P) availability, and the activity of NAD(P)-dependent epigenetic regulator enzymes. It points to an exciting role of dietary niacin intake as a central regulator of physiological processes, e.g., maintenance of genetic stability, and of epigenetic control mechanisms modulating metabolism and aging. Insight into the role of niacin and various NAD-related diseases ranging from cancer, aging, and metabolic diseases to cardiovascular problems has shifted our view of niacin as a vitamin to current views that explore its potential as a therapeutic.
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Affiliation(s)
- James B Kirkland
- Department of Human Health and Nutritional Sciences, University of Guelph, Guelph, ON, Canada
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33
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Hamid HS, Hayes JM, Feldman EL, Lentz SI. Three-dimensional Imaging and Analysis of Mitochondria within Human Intraepidermal Nerve Fibers. J Vis Exp 2017. [PMID: 28994751 DOI: 10.3791/53369] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022] Open
Abstract
The goal of this protocol is to study mitochondria within intraepidermal nerve fibers. Therefore, 3D imaging and analysis techniques were developed to isolate nerve-specific mitochondria and evaluate disease-induced alterations of mitochondria in the distal tip of sensory nerves. The protocol combines fluorescence immunohistochemistry, confocal microscopy and 3D image analysis techniques to visualize and quantify nerve-specific mitochondria. Detailed parameters are defined throughout the procedures in order to provide a concrete example of how to use these techniques to isolate nerve-specific mitochondria. Antibodies were used to label nerve and mitochondrial signals within tissue sections of skin punch biopsies, which was followed by indirect immunofluorescence to visualize nerves and mitochondria with a green and red fluorescent signal respectively. Z-series images were acquired with confocal microscopy and 3D analysis software was used to process and analyze the signals. It is not necessary to follow the exact parameters described within, but it is important to be consistent with the ones chosen throughout the staining, acquisition and analysis steps. The strength of this protocol is that it is applicable to a wide variety of circumstances where one fluorescent signal is used to isolate other signals that would otherwise be impossible to study alone.
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Clark JA, Yeaman EJ, Blizzard CA, Chuckowree JA, Dickson TC. A Case for Microtubule Vulnerability in Amyotrophic Lateral Sclerosis: Altered Dynamics During Disease. Front Cell Neurosci 2016; 10:204. [PMID: 27679561 PMCID: PMC5020100 DOI: 10.3389/fncel.2016.00204] [Citation(s) in RCA: 37] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/23/2016] [Accepted: 08/15/2016] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is an aggressive multifactorial disease converging on a common pathology: the degeneration of motor neurons (MNs), their axons and neuromuscular synapses. This vulnerability and dysfunction of MNs highlights the dependency of these large cells on their intracellular machinery. Neuronal microtubules (MTs) are intracellular structures that facilitate a myriad of vital neuronal functions, including activity dependent axonal transport. In ALS, it is becoming increasingly apparent that MTs are likely to be a critical component of this disease. Not only are disruptions in this intracellular machinery present in the vast majority of seemingly sporadic cases, recent research has revealed that mutation to a microtubule protein, the tubulin isoform TUBA4A, is sufficient to cause a familial, albeit rare, form of disease. In both sporadic and familial disease, studies have provided evidence that microtubule mediated deficits in axonal transport are the tipping point for MN survivability. Axonal transport deficits would lead to abnormal mitochondrial recycling, decreased vesicle and mRNA transport and limited signaling of key survival factors from the neurons peripheral synapses, causing the characteristic peripheral "die back". This disruption to microtubule dependant transport in ALS has been shown to result from alterations in the phenomenon of microtubule dynamic instability: the rapid growth and shrinkage of microtubule polymers. This is accomplished primarily due to aberrant alterations to microtubule associated proteins (MAPs) that regulate microtubule stability. Indeed, the current literature would argue that microtubule stability, particularly alterations in their dynamics, may be the initial driving force behind many familial and sporadic insults in ALS. Pharmacological stabilization of the microtubule network offers an attractive therapeutic strategy in ALS; indeed it has shown promise in many neurological disorders, ALS included. However, the pathophysiological involvement of MTs and their functions is still poorly understood in ALS. Future investigations will hopefully uncover further therapeutic targets that may aid in combating this awful disease.
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Affiliation(s)
- Jayden A Clark
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
| | - Elise J Yeaman
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
| | - Catherine A Blizzard
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
| | - Jyoti A Chuckowree
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
| | - Tracey C Dickson
- Menzies Institute for Medical Research, University of Tasmania Hobart, TAS, Australia
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35
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Bramley JC, Collins SVA, Clark KB, Buchser WJ. Avian axons undergo Wallerian degeneration after injury and stress. J Comp Physiol A Neuroethol Sens Neural Behav Physiol 2016; 202:813-822. [PMID: 27614771 DOI: 10.1007/s00359-016-1123-y] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2015] [Revised: 06/20/2016] [Accepted: 08/31/2016] [Indexed: 12/22/2022]
Abstract
The integrity of long axons is essential for neural communication. Unfortunately, relatively minor stress to a neuron can cause extensive loss of this integrity. Axon degeneration is the cell-intrinsic program that actively deconstructs an axon after injury or damage. Although ultrastructural examination has revealed signs of axon degeneration in vivo, the occurrence and progression of axon degeneration in avian species have not yet been documented in vitro. Here, we use a novel cell culture system with primary embryonic zebra finch retinal ganglion cells to interrogate the properties of avian axon degeneration. First, we establish that both axotomy and a chemically induced injury (taxol and vincristine) are sufficient to initiate degeneration. These events are dependent on a late influx of calcium. In addition, as in mammals, the NAD pathway is involved, since a decrease in NMN with FK866 can reduce degeneration. Importantly, these retinal ganglion cell axons were sensitive to a pressure-induced injury, which may mimic the effect of high intraocular pressure associated with glaucoma. We have demonstrated that avian neurons undergo Wallerian degeneration in response to both physical and chemical injury. Subsequent avian studies will investigate whether blocking the degeneration pathway can protect individuals from neurodegenerative disease.
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Affiliation(s)
- John C Bramley
- Department of Biology, College of William & Mary, 540 Landrum Dr., Williamsburg, VA, USA
| | - Samantha V A Collins
- Department of Biology, College of William & Mary, 540 Landrum Dr., Williamsburg, VA, USA
| | - Karen B Clark
- Department of Biology, College of William & Mary, 540 Landrum Dr., Williamsburg, VA, USA
| | - William J Buchser
- Department of Biology, College of William & Mary, 540 Landrum Dr., Williamsburg, VA, USA.
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36
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Lassus B, Magnifico S, Pignon S, Belenguer P, Miquel MC, Peyrin JM. Alterations of mitochondrial dynamics allow retrograde propagation of locally initiated axonal insults. Sci Rep 2016; 6:32777. [PMID: 27604820 PMCID: PMC5015069 DOI: 10.1038/srep32777] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2016] [Accepted: 08/08/2016] [Indexed: 12/15/2022] Open
Abstract
In chronic neurodegenerative syndromes, neurons progressively die through a generalized retraction pattern triggering retrograde axonal degeneration toward the cell bodies, which molecular mechanisms remain elusive. Recent observations suggest that direct activation of pro-apoptotic signaling in axons triggers local degenerative events associated with early alteration of axonal mitochondrial dynamics. This raises the question of the role of mitochondrial dynamics on both axonal vulnerability stress and their implication in the spreading of damages toward unchallenged parts of the neuron. Here, using microfluidic chambers, we assessed the consequences of interfering with OPA1 and DRP1 proteins on axonal degeneration induced by local application of rotenone. We found that pharmacological inhibition of mitochondrial fission prevented axonal damage induced by rotenone, in low glucose conditions. While alteration of mitochondrial dynamics per se did not lead to spontaneous axonal degeneration, it dramatically enhanced axonal vulnerability to rotenone, which had no effect in normal glucose conditions, and promoted retrograde spreading of axonal degeneration toward the cell body. Altogether, our results suggest a mitochondrial priming effect in axons as a key process of axonal degeneration. In the context of neurodegenerative diseases, like Parkinson's and Alzheimer's, mitochondria fragmentation could hasten neuronal death and initiate spatial dispersion of locally induced degenerative events.
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Affiliation(s)
- Benjamin Lassus
- CNRS UMR 8256, Biological Adaptation and Ageing, Paris, 75005, France.,Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, Paris, 75005, France
| | - Sebastien Magnifico
- CNRS UMR 8256, Biological Adaptation and Ageing, Paris, 75005, France.,Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, Paris, 75005, France
| | - Sandra Pignon
- CNRS UMR 8256, Biological Adaptation and Ageing, Paris, 75005, France.,Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, Paris, 75005, France
| | - Pascale Belenguer
- CNRS UMR 5169 Research Center on Animal Cognition, Center for Integrative Biology, Toulouse University, Université Toulouse 3 Paul Sabatier, 31400, France
| | - Marie-Christine Miquel
- CNRS UMR 5169 Research Center on Animal Cognition, Center for Integrative Biology, Toulouse University, Université Toulouse 3 Paul Sabatier, 31400, France
| | - Jean-Michel Peyrin
- CNRS UMR 8256, Biological Adaptation and Ageing, Paris, 75005, France.,Sorbonne Universités, UPMC, Institut de Biologie Paris-Seine, Paris, 75005, France
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37
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Jang SY, Shin YK, Park SY, Park JY, Lee HJ, Yoo YH, Kim JK, Park HT. Autophagic myelin destruction by Schwann cells during Wallerian degeneration and segmental demyelination. Glia 2015; 64:730-42. [PMID: 26712109 DOI: 10.1002/glia.22957] [Citation(s) in RCA: 109] [Impact Index Per Article: 12.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2015] [Revised: 11/26/2015] [Accepted: 12/02/2015] [Indexed: 01/17/2023]
Abstract
As lysosomal hydrolysis has long been suggested to be responsible for myelin clearance after peripheral nerve injury, in this study, we investigated the possible role of autophagolysosome formation in myelin phagocytosis by Schwann cells and its final contribution to nerve regeneration. We found that the canonical formation of autophagolysosomes was induced in demyelinating Schwann cells after injury, and the inhibition of autophagy via Schwann cell-specific knockout of the atg7 gene or pharmacological intervention of lysosomal function caused a significant delay in myelin clearance. However, Schwann cell dedifferentiation, as demonstrated by extracellular signal-regulated kinase activation and c-Jun induction, and redifferentiation were not significantly affected, and thus the entire repair program progressed normally in atg7 knockout mice. Finally, autophagic Schwann cells were also found during segmental demyelination in a mouse model of inflammatory peripheral neuropathy. Together, our findings suggest that autophagy is the self-myelin destruction mechanism of Schwann cells, but mechanistically, it is a process distinct from Schwann cell plasticity for nerve repair.
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Affiliation(s)
- So Young Jang
- Department of Physiology, Mitochondria Hub Regulation Center, Dong-a University, Busan, Korea
| | - Yoon Kyung Shin
- Department of Physiology, Mitochondria Hub Regulation Center, Dong-a University, Busan, Korea
| | - So Young Park
- Department of Pharmacology, Mitochondria Hub Regulation Center, Dong-a University, Busan, Korea
| | - Joo Youn Park
- Department of Physiology, Mitochondria Hub Regulation Center, Dong-a University, Busan, Korea
| | - Hye Jeong Lee
- Department of Pharmacology, Mitochondria Hub Regulation Center, Dong-a University, Busan, Korea
| | | | - Jong Kuk Kim
- Neurology, College of Medicine, Dong-a University, Busan, Korea
| | - Hwan Tae Park
- Department of Physiology, Mitochondria Hub Regulation Center, Dong-a University, Busan, Korea
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38
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Hamid HS, Mervak CM, Münch AE, Robell NJ, Hayes JM, Porzio MT, Singleton JR, Smith AG, Feldman EL, Lentz SI. Hyperglycemia- and neuropathy-induced changes in mitochondria within sensory nerves. Ann Clin Transl Neurol 2014; 1:799-812. [PMID: 25493271 PMCID: PMC4241807 DOI: 10.1002/acn3.119] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2013] [Revised: 08/19/2014] [Accepted: 08/22/2014] [Indexed: 02/04/2023] Open
Abstract
Objective This study focused on altered mitochondrial dynamics as a potential mechanism for diabetic peripheral neuropathy (DPN). We employed both an in vitro sensory neuron model and an in situ analysis of human intraepidermal nerve fibers (IENFs) from cutaneous biopsies to measure alterations in the size distribution of mitochondria as a result of hyperglycemia and diabetes, respectively. Methods Neurite- and nerve-specific mitochondrial signals within cultured rodent sensory neurons and human IENFs were measured by employing a three-dimensional visualization and quantification technique. Skin biopsies from distal thigh (DT) and distal leg (DL) were analyzed from three groups of patients; patients with diabetes and no DPN, patients with diabetes and confirmed DPN, and healthy controls. Results This analysis demonstrated an increase in mitochondria distributed within the neurites of cultured sensory neurons exposed to hyperglycemic conditions. Similar changes were observed within IENFs of the DT in DPN patients compared to controls. This change was represented by a significant shift in the size frequency distribution of mitochondria toward larger mitochondria volumes within DT nerves of DPN patients. There was a length-dependent difference in mitochondria within IENFs. Distal leg IENFs from control patients had a significant shift toward larger volumes of mitochondrial signal compared to DT IENFs. Interpretation The results of this study support the hypothesis that altered mitochondrial dynamics may contribute to DPN pathogenesis. Future studies will examine the potential mechanisms that are responsible for mitochondrial changes within IENFs and its effect on DPN pathogenesis.
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Affiliation(s)
- Hussein S Hamid
- University of Michigan Medical School, University of Michigan Ann Arbor, Michigan, 48109
| | - Colin M Mervak
- Department of Neurology, University of Michigan Ann Arbor, Michigan, 48109
| | - Alexandra E Münch
- Division on Metabolism Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Ann Arbor, Michigan, 48105
| | - Nicholas J Robell
- Department of Neurology, University of Michigan Ann Arbor, Michigan, 48109
| | - John M Hayes
- Department of Neurology, University of Michigan Ann Arbor, Michigan, 48109
| | - Michael T Porzio
- Department of Neurology, University of Utah School of Medicine Salt Lake City, Utah, 84132
| | - J Robinson Singleton
- Department of Neurology, University of Utah School of Medicine Salt Lake City, Utah, 84132
| | - A Gordon Smith
- Department of Neurology, University of Utah School of Medicine Salt Lake City, Utah, 84132
| | - Eva L Feldman
- Department of Neurology, University of Michigan Ann Arbor, Michigan, 48109
| | - Stephen I Lentz
- Division on Metabolism Endocrinology and Diabetes, Department of Internal Medicine, University of Michigan Ann Arbor, Michigan, 48105
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Park JY, Jang SY, Shin YK, Suh DJ, Park HT. Calcium-dependent proteasome activation is required for axonal neurofilament degradation. Neural Regen Res 2014; 8:3401-9. [PMID: 25206662 PMCID: PMC4146008 DOI: 10.3969/j.issn.1673-5374.2013.36.005] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/05/2013] [Accepted: 11/28/2013] [Indexed: 12/17/2022] Open
Abstract
Even though many studies have identified roles of proteasomes in axonal degeneration, the molecular mechanisms by which axonal injury regulates proteasome activity are still unclear. In the present study, we found evidence indicating that extracellular calcium influx is an upstream regulator of proteasome activity during axonal degeneration in injured peripheral nerves. In degenerating axons, the increase in proteasome activity and the degradation of ubiquitinated proteins were significantly suppressed by extracellular calcium chelation. In addition, electron microscopic findings revealed selective inhibition of neurofilament degradation, but not microtubule depolymerization or mitochondrial swelling, by the inhibition of calpain and proteasomes. Taken together, our findings suggest that calcium increase and subsequent proteasome activation are an essential initiator of neurofilament degradation in Wallerian degeneration.
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Affiliation(s)
- Joo Youn Park
- Department of Physiology, Mitochondria Hub Regulation Center, College of Medicine, Dong-A University, Busan, South Korea
| | - So Young Jang
- Department of Physiology, Mitochondria Hub Regulation Center, College of Medicine, Dong-A University, Busan, South Korea
| | - Yoon Kyung Shin
- Department of Physiology, Mitochondria Hub Regulation Center, College of Medicine, Dong-A University, Busan, South Korea
| | - Duk Joon Suh
- Department of Physiology, Mitochondria Hub Regulation Center, College of Medicine, Dong-A University, Busan, South Korea
| | - Hwan Tae Park
- Department of Physiology, Mitochondria Hub Regulation Center, College of Medicine, Dong-A University, Busan, South Korea
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40
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Abstract
Mitochondrial dysfunction is the underlying cause of many neurological disorders, including peripheral neuropathies. Mitochondria rely on a proton gradient to generate ATP and interfering with electron transport chain function can lead to the deleterious accumulation of reactive oxygen species (ROS). Notably, loss of mitochondrial potential precedes cellular demise in several programmed cell destruction pathways, including axons undergoing Wallerian degeneration. Here, we demonstrate that mitochondrial depolarization triggers axon degeneration and cell death in primary mouse sensory neurons. These degenerative events are not blocked by inhibitors of canonical programmed cell death pathways such as apoptosis, necroptosis, and parthanatos. Instead, the axodestructive factor Sarm1 is required for this axon degeneration and cell death. In the absence of Sarm1, the mitochondrial poison CCCP still induces depolarization of mitochondria, ATP depletion, calcium influx, and the accumulation of ROS, yet cell death and axon degeneration are blocked. The survival of these neurons despite the accumulation of ROS indicates that Sarm1 acts downstream of ROS generation. Indeed, loss of Sarm1 protects sensory neurons and their axons from prolonged exposure to ROS. Therefore, Sarm1 functions downstream of ROS to induce neuronal cell death and axon degeneration during oxidative stress. These findings highlight the central role for Sarm1 in a novel form of programmed cell destruction that we term sarmoptosis.
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41
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Yang RL, Wang XT, Liu DW, Liu SB. Energy and oxygen metabolism disorder during septic acute kidney injury. Kidney Blood Press Res 2014; 39:240-51. [PMID: 25171106 DOI: 10.1159/000355801] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2014] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Acute kidney injury (AKI) during septic shock, which is one of the most common clinical syndromes in the intensive care unit (ICU), has a high mortality rate and poor prognosis, partly because of a poor understanding of the pathogenesis of renal dysfunction during septic shock. Although ischemic injury of the kidney has been reported to result from adenosine triphosphate (ATP) depletion, increasing evidence has demonstrated that AKI occurs in the absence of renal hypoperfusion and even occurs during normal or increased renal blood flow (RBF); nevertheless, whether energy metabolism disorder is involved in septic AKI and whether it changes according to renal hemodynamics have not been established. Moreover, tubular cell apoptosis, which is closely related to ATP depletion, rather than necrosis, has been shown to be the major form of cell injury during AKI. METHODS We used canine endotoxin shock models to investigate the hemodynamics, renal energy metabolism, renal oxygen metabolism, and pathological changes during septic AKI and to explore the underlying mechanisms of septic AKI. RESULTS The present results revealed that the nicotinamide adenine dinucleotide (NAD+) pool and the ATP/adenosine diphosphate (ADP) ratio were significantly decreased during the early phase of septic AKI, which is accompanied by a decreased renal oxygen extraction ratio (O2ER%) and decreased renal oxygen consumption (VO2). Furthermore, significant apoptosis was observed following renal dysfunction. RBF and renal oxygen delivery were not significantly altered. CONCLUSION These results suggest that imbalanced energy metabolism, rather than tubular cell apoptosis, may be the initiator of renal dysfunction during septic shock.
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Affiliation(s)
- Rong-li Yang
- Critical Care Medicine Department, Peking Union Medical College Hospital, Peking Union Medical College and Chinese Academy of Medical Sciences, Beijing 100730, China
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42
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Bros H, Millward JM, Paul F, Niesner R, Infante-Duarte C. Oxidative damage to mitochondria at the nodes of Ranvier precedes axon degeneration in ex vivo transected axons. Exp Neurol 2014; 261:127-35. [PMID: 24973623 DOI: 10.1016/j.expneurol.2014.06.018] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/07/2014] [Revised: 05/23/2014] [Accepted: 06/18/2014] [Indexed: 12/11/2022]
Abstract
Oxidative stress and mitochondrial dysfunction appear to contribute to axon degeneration in numerous neurological disorders. However, how these two processes interact to cause axonal damage-and how this damage is initiated-remains unclear. In this study we used transected motor axons from murine peripheral roots to investigate whether oxidative stress alters mitochondrial dynamics in myelinated axons. We show that the nodes of Ranvier are the initial sites of mitochondrial damage induced by oxidative stress. There, mitochondria became depolarized, followed by alterations of the external morphology and disruption of the cristae, along with reduced mitochondrial transport. These mitochondrial changes expanded from the nodes of Ranvier bidirectionally towards both internodes and eventually affected the entire mitochondrial population in the axon. Supplementing axonal bioenergetics by applying nicotinamide adenine dinucleotide and methyl pyruvate, rendered the mitochondria at the nodes of Ranvier resistant to these oxidative stress-induced changes. Importantly, this inhibition of mitochondrial damage protected the axons from degeneration. In conclusion, we present a novel ex vivo approach for monitoring mitochondrial dynamics within axons, which proved suitable for detecting mitochondrial changes upon exogenous application of oxidative stress. Our results indicate that the nodes of Ranvier are the site of initial mitochondrial damage in peripheral axons, and suggest that dysregulation of axonal bioenergetics plays a critical role in oxidative stress-triggered mitochondrial alterations and subsequent axonal injury. These novel insights into the mechanisms underlying axon degeneration may have implications for neurological disorders with a degenerative component.
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Affiliation(s)
- Helena Bros
- Institute for Medical Immunology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; Experimental and Clinical Research Center, a joint cooperation between the Charité-Universitätsmedizin Berlin and the Max-Delbrück Center for Molecular Medicine, Lindenberger Weg 80, 13125 Berlin, Germany; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
| | - Jason M Millward
- Institute for Medical Immunology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; Experimental and Clinical Research Center, a joint cooperation between the Charité-Universitätsmedizin Berlin and the Max-Delbrück Center for Molecular Medicine, Lindenberger Weg 80, 13125 Berlin, Germany.
| | - Friedemann Paul
- Experimental and Clinical Research Center, a joint cooperation between the Charité-Universitätsmedizin Berlin and the Max-Delbrück Center for Molecular Medicine, Lindenberger Weg 80, 13125 Berlin, Germany; NeuroCure Clinical Research Center, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany; Clinical and Experimental Multiple Sclerosis Research Center, Department of Neurology, Charité-Universitätsmedizin Berlin, Charitéplatz 1, 10117 Berlin, Germany.
| | - Raluca Niesner
- Deutsches Rheuma-Forschungszentrum, Charitéplatz 1, 10117 Berlin, Germany.
| | - Carmen Infante-Duarte
- Institute for Medical Immunology, Charité-Universitätsmedizin Berlin, Augustenburger Platz 1, 13353 Berlin, Germany; Experimental and Clinical Research Center, a joint cooperation between the Charité-Universitätsmedizin Berlin and the Max-Delbrück Center for Molecular Medicine, Lindenberger Weg 80, 13125 Berlin, Germany.
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Hao N, Lü G, Liu X, Yu B, Wu H, Ji D, Li Y, Han X. Potential role of microRNA: identification and functional analysis of microRNA in corticospinal tract after unilateral lesions of the medullary pyramid. Neurosci Lett 2014; 564:37-42. [PMID: 24513234 DOI: 10.1016/j.neulet.2013.12.050] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/06/2013] [Revised: 12/19/2013] [Accepted: 12/22/2013] [Indexed: 12/14/2022]
Abstract
Corticospinal tract is mainly descending tracts by dominating voluntary movement of the limbs and fine movement of distal limb, especially in mammals. Distal axonal degeneration is called anterograde degeneration. Proximal end is connected to the neuron cell body, whereas retrograde degeneration is very slight with the possibility of regeneration. MicroRNAs (miRNAs) are a short non-coding RNAs that regulate gene expression at the post-transcriptional level by binding with the 3' untranslated region of target mRNAs. In order to understand the mechanism of underlying gene alteration in the rostral and caudal, respectively, after the corticospinal tract injury, we analyzed rostral and caudal mRNA and miRNA, respectively, using microRNA and mRNA profiles. We combined the predicted targets of miRNA with differentially expressed mRNA for selecting intersection gene. To predict the function miRNAs, GO and KEGG enrichment analysis were performed to find genes associated with change of rostral and caudal, respectively. The bioinformatics analysis indicated that changes in miRNA and target mRNA expression affected rostral regeneration, including negative regulation of apoptosis, positive regulation of cell proliferation, cell adhesion, oligodendrocyte development etc. It also affected caudal degeneration, including induction of apoptosis, down-regulating nervous system development, immune response etc. The current results illustrated that corticospinal tract injury produces a wide range changes of miRNAs, whereas mRNA also showed significantly change which affects key biological processes after injury in rostral and caudal.
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Affiliation(s)
- Ning Hao
- Department of Anatomy and Neurobiology, the Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Guangming Lü
- Department of Anatomy and Neurobiology, the Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China.
| | - Xiaodong Liu
- Department of Anatomy and Neurobiology, the Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Bin Yu
- Department of Anatomy and Neurobiology, the Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Huiqun Wu
- Department of Anatomy and Neurobiology, the Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Dafeng Ji
- Department of Anatomy and Neurobiology, the Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Yaofu Li
- Department of Anatomy and Neurobiology, the Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China
| | - Xiao Han
- Department of Anatomy and Neurobiology, the Jiangsu Key Laboratory of Neuroregeneration, Nantong University, Nantong 226001, China
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Sodium channels contribute to degeneration of dorsal root ganglion neurites induced by mitochondrial dysfunction in an in vitro model of axonal injury. J Neurosci 2014; 33:19250-61. [PMID: 24305821 DOI: 10.1523/jneurosci.2148-13.2013] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022] Open
Abstract
Axonal degeneration occurs in multiple neurodegenerative disorders of the central and peripheral nervous system. Although the underlying molecular pathways leading to axonal degeneration are incompletely understood, accumulating evidence suggests contributions of impaired mitochondrial function, disrupted axonal transport, and/or dysfunctional intracellular Ca(2+)-homeostasis in the injurious cascade associated with axonal degeneration. Utilizing an in vitro model of axonal degeneration, we studied a subset of mouse peripheral sensory neurons in which neurites were exposed selectively to conditions associated with the pathogenesis of axonal neuropathies in vivo. Rotenone-induced mitochondrial dysfunction resulted in neurite degeneration accompanied by reduced ATP levels and increased ROS levels in neurites. Blockade of voltage-gated sodium channels with TTX and reverse (Ca(2+)-importing) mode of the sodium-calcium exchanger (NCX) with KB-R7943 partially protected rotenone-treated neurites from degeneration, suggesting a contribution of sodium channels and reverse NCX activity to the degeneration of neurites resulting from impaired mitochondrial function. Pharmacological inhibition of the Na(+)/K(+)-ATPase with ouabain induced neurite degeneration, which was attenuated by TTX and KB-R7943, supporting a contribution of sodium channels in axonal degenerative pathways accompanying impaired Na(+)/K(+)-ATPase activity. Conversely, oxidant stress (H2O2)-induced neurite degeneration was not attenuated by TTX. Our results demonstrate that both energetic and oxidative stress targeted selectively to neurites induces neurite degeneration and that blockade of sodium channels and of reverse NCX activity blockade partially protects neurites from injury due to energetic stress, but not from oxidative stress induced by H2O2.
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