1
|
Deck M, Van Hameren G, Campbell G, Bernard-Marissal N, Devaux J, Berthelot J, Lattard A, Médard JJ, Gautier B, Guelfi S, Abbou S, Quintana P, Chao de la Barca JM, Reynier P, Lenaers G, Chrast R, Tricaud N. Physiology of PNS axons relies on glycolytic metabolism in myelinating Schwann cells. PLoS One 2022; 17:e0272097. [PMID: 36194565 PMCID: PMC9531822 DOI: 10.1371/journal.pone.0272097] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/02/2022] [Accepted: 07/12/2022] [Indexed: 11/18/2022] Open
Abstract
While lactate shuttle theory states that glial cells metabolize glucose into lactate to shuttle it to neurons, how glial cells support axonal metabolism and function remains unclear. Lactate production is a common occurrence following anaerobic glycolysis in muscles. However, several other cell types, including some stem cells, activated macrophages and tumor cells, can produce lactate in presence of oxygen and cellular respiration, using Pyruvate Kinase 2 (PKM2) to divert pyruvate to lactate dehydrogenase. We show here that PKM2 is also upregulated in myelinating Schwann cells (mSC) of mature mouse sciatic nerve versus postnatal immature nerve. Deletion of this isoform in PLP-expressing cells in mice leads to a deficit of lactate in mSC and in peripheral nerves. While the structure of myelin sheath was preserved, mutant mice developed a peripheral neuropathy. Peripheral nerve axons of mutant mice failed to maintain lactate homeostasis upon activity, resulting in an impaired production of mitochondrial ATP. Action potential propagation was not altered but axonal mitochondria transport was slowed down, muscle axon terminals retracted and motor neurons displayed cellular stress. Additional reduction of lactate availability through dichloroacetate treatment, which diverts pyruvate to mitochondrial oxidative phosphorylation, further aggravated motor dysfunction in mutant mice. Thus, lactate production through PKM2 enzyme and aerobic glycolysis is essential in mSC for the long-term maintenance of peripheral nerve axon physiology and function.
Collapse
Affiliation(s)
- Marie Deck
- INM, INSERM, Université de Montpellier, Montpellier, France
- * E-mail: (NT); (MD)
| | | | | | | | - Jérôme Devaux
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Jade Berthelot
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Alise Lattard
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Jean-Jacques Médard
- Departments of Clinical Neuroscience and Neuroscience, Karolinska Intitutet, Stockholm, Sweden
| | - Benoît Gautier
- INM, INSERM, Université de Montpellier, Montpellier, France
| | - Sophie Guelfi
- INM, INSERM, Université de Montpellier, Montpellier, France
| | | | | | - Juan Manuel Chao de la Barca
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France
- Equipe Mitolab, MITOVASC, CNRS 6015, INSERM U1083, Université d’Angers, Angers, France
| | - Pascal Reynier
- Département de Biochimie et Génétique, Centre Hospitalier Universitaire, Angers, France
- Equipe Mitolab, MITOVASC, CNRS 6015, INSERM U1083, Université d’Angers, Angers, France
| | - Guy Lenaers
- Equipe Mitolab, MITOVASC, CNRS 6015, INSERM U1083, Université d’Angers, Angers, France
| | - Roman Chrast
- Departments of Clinical Neuroscience and Neuroscience, Karolinska Intitutet, Stockholm, Sweden
| | - Nicolas Tricaud
- I-Stem, UEVE/UPS U861, INSERM, AFM, Corbeil-Essonnes, France
- * E-mail: (NT); (MD)
| |
Collapse
|
2
|
Tricaud N, Gautier B, Berthelot J, Gonzalez S, Van Hameren G. Traumatic and Diabetic Schwann Cell Demyelination Is Triggered by a Transient Mitochondrial Calcium Release through Voltage Dependent Anion Channel 1. Biomedicines 2022; 10:biomedicines10061447. [PMID: 35740468 PMCID: PMC9220872 DOI: 10.3390/biomedicines10061447] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2022] [Revised: 06/07/2022] [Accepted: 06/08/2022] [Indexed: 11/16/2022] Open
Abstract
A large number of peripheral neuropathies, among which are traumatic and diabetic peripheral neuropathies, result from the degeneration of the myelin sheath, a process called demyelination. Demyelination does not result from Schwann cell death but from Schwann cell dedifferentiation, which includes reprograming and several catabolic and anabolic events. Starting around 4 h after nerve injury, activation of MAPK/cJun pathways is the earliest characterized step of this dedifferentiation program. Here we show, using real-time in vivo imaging, that Schwann cell mitochondrial pH, motility and calcium content are altered as soon as one hour after nerve injury. Mitochondrial calcium release occurred through the VDAC outer membrane channel and mPTP inner membrane channel. This calcium influx in the cytoplasm induced Schwann-cell demyelination via MAPK/c-Jun activation. Blocking calcium release through VDAC silencing or VDAC inhibitor TRO19622 prevented demyelination. We found that the kinetics of mitochondrial calcium release upon nerve injury were altered in the Schwann cells of diabetic mice suggesting a permanent leak of mitochondrial calcium in the cytoplasm. TRO19622 treatment alleviated peripheral nerve defects and motor deficit in diabetic mice. Together, these data indicate that mitochondrial calcium homeostasis is instrumental in the Schwann cell demyelination program and that blocking VDAC constitutes a molecular basis for developing anti-demyelinating drugs for diabetic peripheral neuropathy.
Collapse
Affiliation(s)
- Nicolas Tricaud
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
- I-Stem, UEVE/UPS U861, INSERM U861, AFM, 91100 Corbeil-Essonnes, France
- Correspondence:
| | - Benoit Gautier
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
| | - Jade Berthelot
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
| | - Sergio Gonzalez
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
| | - Gerben Van Hameren
- Institut des Neurosciences de Montpellier, Univ. Montpellier, INSERM, 34000 Montpellier, France; (B.G.); (J.B.); (S.G.); (G.V.H.)
| |
Collapse
|
3
|
Wang Y, Xu Y, Zhou K, Zhang S, Wang Y, Li T, Xie C, Zhang X, Song J, Wang X, Zhu C. Autophagy Inhibition Reduces Irradiation-Induced Subcortical White Matter Injury Not by Reducing Inflammation, but by Increasing Mitochondrial Fusion and Inhibiting Mitochondrial Fission. Mol Neurobiol 2021; 59:1199-1213. [PMID: 34962635 PMCID: PMC8857090 DOI: 10.1007/s12035-021-02653-x] [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: 03/12/2021] [Accepted: 11/15/2021] [Indexed: 12/12/2022]
Abstract
Radiotherapy is an effective tool in the treatment of malignant brain tumors, but irradiation-induced late-onset toxicity remains a major problem. The purpose of this study was to investigate if genetic inhibition of autophagy has an impact on subcortical white matter development in the juvenile mouse brain after irradiation. Ten-day-old selective neural Atg7 knockout (KO) mice and wild-type (WT) littermates were subjected to a single 6-Gy dose of whole-brain irradiation and evaluated at 5 days after irradiation. Neural Atg7 deficiency partially prevented myelin disruption compared to the WT mice after irradiation, as indicated by myelin basic protein staining. Irradiation induced oligodendrocyte progenitor cell loss in the subcortical white matter, and Atg7 deficiency partly prevented this. There was no significant change between the KO and WT mice in the number of microglia and astrocytes in the subcortical white matter after irradiation. Transcriptome analysis showed that the GO mitochondrial gene expression pathway was significantly enriched in the differentially expressed genes between the KO and WT group after irradiation. Compared with WT mice, expression of the mitochondrial fusion protein OPA1 and phosphorylation of the mitochondrial fission protein DRP1 (P-DRP1) were dramatically decreased in KO mice under physiological conditions. The protein levels of OPA1and P-DRP1 showed no differences in WT mice between the non-irradiated group and the irradiated group but had remarkably increased levels in the KO mice after irradiation. These results indicate that inhibition of autophagy reduces irradiation-induced subcortical white matter injury not by reducing inflammation, but by increasing mitochondrial fusion and inhibiting mitochondrial fission.
Collapse
Affiliation(s)
- Yafeng Wang
- Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Children's Hospital Affiliated To Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, 450018, China.,Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530, Göteborg, Sweden
| | - Yiran Xu
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530, Göteborg, Sweden
| | - Kai Zhou
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530, Göteborg, Sweden.,Department of Women's and Children's Health, Karolinska Institute, 17176, Stockholm, Sweden
| | - Shan Zhang
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530, Göteborg, Sweden
| | - Yong Wang
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530, Göteborg, Sweden
| | - Tao Li
- Henan Provincial Key Laboratory of Children's Genetics and Metabolic Diseases, Children's Hospital Affiliated To Zhengzhou University, Henan Children's Hospital, Zhengzhou Children's Hospital, Zhengzhou, 450018, China.,Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530, Göteborg, Sweden
| | - Cuicui Xie
- Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530, Göteborg, Sweden.,Department of Women's and Children's Health, Karolinska Institute, 17176, Stockholm, Sweden
| | - Xiaoli Zhang
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Juan Song
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China
| | - Xiaoyang Wang
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China.,Centre for Perinatal Medicine and Health, Institute of Clinical Sciences, Sahlgrenska Academy, Gothenburg University, 40530, Gothenburg, Sweden
| | - Changlian Zhu
- Henan Key Laboratory of Child Brain Injury and Henan Pediatric Clinical Research Center, Institute of Neuroscience and Third Affiliated Hospital of Zhengzhou University, Zhengzhou, 450052, China. .,Center for Brain Repair and Rehabilitation, Institute of Neuroscience and Physiology, Sahlgrenska Academy, University of Gothenburg, 40530, Göteborg, Sweden. .,Department of Women's and Children's Health, Karolinska Institute, 17176, Stockholm, Sweden.
| |
Collapse
|
4
|
Mitochondria in Myelinating Oligodendrocytes: Slow and Out of Breath? Metabolites 2021; 11:metabo11060359. [PMID: 34198810 PMCID: PMC8226700 DOI: 10.3390/metabo11060359] [Citation(s) in RCA: 33] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/11/2021] [Revised: 06/01/2021] [Accepted: 06/02/2021] [Indexed: 12/23/2022] Open
Abstract
Myelin is a lipid-rich membrane that wraps around axons and facilitates rapid action potential propagation. In the brain, myelin is synthesized and maintained by oligodendrocytes. These cells have a high metabolic demand that requires mitochondrial ATP production during the process of myelination, but they rely less on mitochondrial respiration after myelination is complete. Mitochondria change in morphology and distribution during oligodendrocyte development. Furthermore, the morphology and dynamic properties of mitochondria in mature oligodendrocytes seem different from any other brain cell. Here, we first give a brief introduction to oligodendrocyte biology and function. We then review the current knowledge on oligodendrocyte metabolism and discuss how the available data on mitochondrial morphology and mobility as well as transcriptome and proteome studies can shed light on the metabolic properties of oligodendrocytes.
Collapse
|
5
|
Bikmulina PY, Kosheleva NV, Shpichka AI, Efremov YM, Yusupov VI, Timashev PS, Rochev YA. Beyond 2D: effects of photobiomodulation in 3D tissue-like systems. JOURNAL OF BIOMEDICAL OPTICS 2020; 25:1-16. [PMID: 32351077 PMCID: PMC7189416 DOI: 10.1117/1.jbo.25.4.048001] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/12/2020] [Accepted: 04/09/2020] [Indexed: 05/02/2023]
Abstract
SIGNIFICANCE Currently, various scaffolds with immobilized cells are widely used in tissue engineering and regenerative medicine. However, the physiological activity and cell viability in such constructs might be impaired due to a lack of oxygen and nutrients. Photobiomodulation (PBM) is a promising method of preconditioning cells to increase their metabolic activity and to activate proliferation or differentiation. AIM Investigation of the potential of PBM for stimulation of cell activities in hydrogels. APPROACH Mesenchymal stromal cells (MSCs) isolated from human gingival mucosa were encapsulated in modified fibrin hydrogels with different thicknesses and concentrations. Constructs with cells were subjected to a single-time exposure to red (630 nm) and near-infrared (IR) (840 nm) low-intensity irradiation. After 3 days of cultivation, the viability and physiological activity of the cells were analyzed using confocal microscopy and a set of classical tests for cytotoxicity. RESULTS The cell viability in fibrin hydrogels depended both on the thickness of the hydrogels and the concentration of gel-forming proteins. The PBM was able to improve cell viability in hydrogels. The most pronounced effect was achieved with near-IR irradiation at the 840-nm wavelength. CONCLUSIONS PBM using near-IR light can be applied for stimulation of MSCs metabolism and proliferation in hydrogel-based constructs with thicknesses up to 3 mm.
Collapse
Affiliation(s)
- Polina Y. Bikmulina
- Sechenov First Moscow State Medical University, Institute for Regenerative Medicine, Moscow, Russia
| | - Nastasia V. Kosheleva
- Lomonosov Moscow State University, Faculty of Biology, Moscow, Russia
- FSBSI “Institute of General Pathology and Pathophysiology,” Moscow, Russia
- FSBEI FPE “Russian Medical Academy of Continuous Professional Education,” Ministry of Healthcare of Russia, Moscow, Russia
| | - Anastasia I. Shpichka
- Sechenov First Moscow State Medical University, Institute for Regenerative Medicine, Moscow, Russia
- Lomonosov Moscow State University, Chemistry Department, Moscow, Russia
| | - Yuri M. Efremov
- Sechenov First Moscow State Medical University, Institute for Regenerative Medicine, Moscow, Russia
| | - Vladimir I. Yusupov
- Institute of Photon Technologies of FSRC “Crystallography and Photonics” RAS, Troitsk, Moscow, Russia
| | - Peter S. Timashev
- Sechenov First Moscow State Medical University, Institute for Regenerative Medicine, Moscow, Russia
- Lomonosov Moscow State University, Chemistry Department, Moscow, Russia
- Institute of Photon Technologies of FSRC “Crystallography and Photonics” RAS, Troitsk, Moscow, Russia
- N.N. Semenov Institute of Chemical Physics, Department of Polymers and Composites, Moscow, Russia
| | - Yury A. Rochev
- Sechenov First Moscow State Medical University, Institute for Regenerative Medicine, Moscow, Russia
- National University of Ireland, National Centre for Biomedical Engineering Science, Galway, Ireland
| |
Collapse
|
6
|
van Hameren G, Campbell G, Deck M, Berthelot J, Gautier B, Quintana P, Chrast R, Tricaud N. In vivo real-time dynamics of ATP and ROS production in axonal mitochondria show decoupling in mouse models of peripheral neuropathies. Acta Neuropathol Commun 2019; 7:86. [PMID: 31186069 PMCID: PMC6558672 DOI: 10.1186/s40478-019-0740-4] [Citation(s) in RCA: 39] [Impact Index Per Article: 7.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2019] [Accepted: 05/16/2019] [Indexed: 12/31/2022] Open
Abstract
Mitochondria are critical for the function and maintenance of myelinated axons notably through Adenosine triphosphate (ATP) production. A direct by-product of this ATP production is reactive oxygen species (ROS), which are highly deleterious for neurons. While ATP shortage and ROS levels increase are involved in several neurodegenerative diseases, it is still unclear whether the real-time dynamics of both ATP and ROS production in axonal mitochondria are altered by axonal or demyelinating neuropathies. To answer this question, we imaged and quantified mitochondrial ATP and hydrogen peroxide (H2O2) in resting or stimulated peripheral nerve myelinated axons in vivo, using genetically-encoded fluorescent probes, two-photon time-lapse and CARS imaging. We found that ATP and H2O2 productions are intrinsically higher in nodes of Ranvier even in resting conditions. Axonal firing increased both ATP and H2O2 productions but with different dynamics: ROS production peaked shortly and transiently after the stimulation while ATP production increased gradually for a longer period of time. In neuropathic MFN2R94Q mice, mimicking Charcot-Marie-Tooth 2A disease, defective mitochondria failed to upregulate ATP production following axonal activity. However, elevated H2O2 production was largely sustained. Finally, inducing demyelination with lysophosphatidylcholine resulted in a reduced level of ATP while H2O2 level soared. Taken together, our results suggest that ATP and ROS productions are decoupled under neuropathic conditions, which may compromise axonal function and integrity.
Collapse
Affiliation(s)
- Gerben van Hameren
- Institut des Neurosciences de Montpellier, INSERM U1051, Université de Montpellier, 34091, Montpellier, France.
| | - Graham Campbell
- Institut des Neurosciences de Montpellier, INSERM U1051, Université de Montpellier, 34091, Montpellier, France
| | - Marie Deck
- Institut des Neurosciences de Montpellier, INSERM U1051, Université de Montpellier, 34091, Montpellier, France
| | - Jade Berthelot
- Institut des Neurosciences de Montpellier, INSERM U1051, Université de Montpellier, 34091, Montpellier, France
| | - Benoit Gautier
- Institut des Neurosciences de Montpellier, INSERM U1051, Université de Montpellier, 34091, Montpellier, France
| | - Patrice Quintana
- Institut des Neurosciences de Montpellier, INSERM U1051, Université de Montpellier, 34091, Montpellier, France
| | - Roman Chrast
- Department of Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden
- Department of Clinical Neuroscience, Karolinska Institutet, 171 77, Stockholm, Sweden
| | - Nicolas Tricaud
- Institut des Neurosciences de Montpellier, INSERM U1051, Université de Montpellier, 34091, Montpellier, France.
| |
Collapse
|
7
|
Altered interplay between endoplasmic reticulum and mitochondria in Charcot-Marie-Tooth type 2A neuropathy. Proc Natl Acad Sci U S A 2019; 116:2328-2337. [PMID: 30659145 DOI: 10.1073/pnas.1810932116] [Citation(s) in RCA: 68] [Impact Index Per Article: 13.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/25/2022] Open
Abstract
Mutations in the MFN2 gene encoding Mitofusin 2 lead to the development of Charcot-Marie-Tooth type 2A (CMT2A), a dominant axonal form of peripheral neuropathy. Mitofusin 2 is localized at both the outer membrane of mitochondria and the endoplasmic reticulum and is particularly enriched at specialized contact regions known as mitochondria-associated membranes (MAM). We observed that expression of MFN2R94Q induces distal axonal degeneration in the absence of overt neuronal death. The presence of mutant protein leads to reduction in endoplasmic reticulum and mitochondria contacts in CMT2A patient-derived fibroblasts, in primary neurons and in vivo, in motoneurons of a mouse model of CMT2A. These changes are concomitant with endoplasmic reticulum stress, calcium handling defects, and changes in the geometry and axonal transport of mitochondria. Importantly, pharmacological treatments reinforcing endoplasmic reticulum-mitochondria cross-talk, or reducing endoplasmic reticulum stress, restore the mitochondria morphology and prevent axonal degeneration. These results highlight defects in MAM as a cellular mechanism contributing to CMT2A pathology mediated by mutated MFN2.
Collapse
|
8
|
Hajjar H, Boukhaddaoui H, Rizgui A, Sar C, Berthelot J, Perrin-Tricaud C, Rigneault H, Tricaud N. Label-free non-linear microscopy to measure myelin outcome in a rodent model of Charcot-Marie-Tooth diseases. JOURNAL OF BIOPHOTONICS 2018; 11:e201800186. [PMID: 30091529 DOI: 10.1002/jbio.201800186] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 05/16/2018] [Revised: 07/27/2018] [Accepted: 08/07/2018] [Indexed: 05/21/2023]
Abstract
Myelin sheath produced by Schwann cells covers and nurtures axons to speed up nerve conduction in peripheral nerves. Demyelinating peripheral neuropathies result from the loss of this myelin sheath and so far, no treatment exists to prevent Schwann cell demyelination. One major hurdle to design a therapy for demyelination is the lack of reliable measures to evaluate the outcome of the treatment on peripheral myelin in patients but also in living animal models. Non-linear microscopy techniques which include second harmonic generation (SHG), third harmonic generation (THG) and coherent anti-stokes Raman scattering (CARS) were used to image myelin ex vivo and in vivo in the sciatic nerve of healthy and demyelinating mice and rats. SHG did not label myelin and THG required too much light power to be compatible with live imaging. CARS is the most reliable of these techniques for in vivo imaging and it allows for the analysis and quantification of myelin defects in a rat model of CMT1A disease. This microscopic technique therefore constitutes a promising, reliable and robust readout tool in the development of new treatments for demyelinating peripheral neuropathies.
Collapse
Affiliation(s)
- Helene Hajjar
- Institut des Neurosciences de Montpellier, Université de Montpellier, Montpellier, France
| | - Hassan Boukhaddaoui
- Institut des Neurosciences de Montpellier, Université de Montpellier, Montpellier, France
- Montpellier Ressources Imagerie (MRI), Montpellier, France
| | - Amel Rizgui
- Institut des Neurosciences de Montpellier, Université de Montpellier, Montpellier, France
| | - Chamroeun Sar
- Institut des Neurosciences de Montpellier, Université de Montpellier, Montpellier, France
- Montpellier Ressources Imagerie (MRI), Montpellier, France
| | - Jade Berthelot
- Institut des Neurosciences de Montpellier, Université de Montpellier, Montpellier, France
| | - Claire Perrin-Tricaud
- Institut des Neurosciences de Montpellier, Université de Montpellier, Montpellier, France
| | - Herve Rigneault
- CNRS, École Centrale Marseille, Institut Fresnel, Aix-Marseille Université, Marseille, France
| | - Nicolas Tricaud
- Institut des Neurosciences de Montpellier, Université de Montpellier, Montpellier, France
| |
Collapse
|
9
|
Tricaud N, Park HT. Wallerian demyelination: chronicle of a cellular cataclysm. Cell Mol Life Sci 2017; 74:4049-4057. [PMID: 28600652 PMCID: PMC5641270 DOI: 10.1007/s00018-017-2565-2] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/17/2017] [Revised: 05/10/2017] [Accepted: 06/01/2017] [Indexed: 12/23/2022]
Abstract
Wallerian demyelination is characteristic of peripheral nerve degeneration after traumatic injury. After axonal degeneration, the myelinated Schwann cell undergoes a stereotypical cellular program that results in the disintegration of the myelin sheath, a process termed demyelination. In this review, we chronologically describe this program starting from the late and visible features of myelin destruction and going backward to the initial molecular steps that trigger the nuclear reprogramming few hours after injury. Wallerian demyelination is a wonderful model for myelin degeneration occurring in the diverse forms of demyelinating peripheral neuropathies that plague human beings.
Collapse
Affiliation(s)
- Nicolas Tricaud
- INSERM U1051, Institut des Neurosciences de Montpellier (INM), Université de Montpellier, Montpellier, France.
| | - Hwan Tae Park
- Peripheral Neuropathy Research Center, Department of Physiology, College of Medicine, Dong-A University, Busan, South Korea
| |
Collapse
|
10
|
Rougon G, Brasselet S, Debarbieux F. Advances in Intravital Non-Linear Optical Imaging of the Central Nervous System in Rodents. Brain Plast 2016; 2:31-48. [PMID: 29765847 PMCID: PMC5928564 DOI: 10.3233/bpl-160028] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022] Open
Abstract
Purpose of review: Highly coordinated cellular interactions occur in the healthy or pathologic adult rodent central nervous system (CNS). Until recently, technical challenges have restricted the analysis of these events to largely static modes of study such as immuno-fluorescence and electron microscopy on fixed tissues. The development of intravital imaging with subcellular resolution is required to probe the dynamics of these events in their natural context, the living brain. Recent findings: This review focuses on the recently developed live non-linear optical imaging modalities, the core principles involved, the identified technical challenges that limit their use and the scope of their applications. We highlight some practical applications for these modalities with a specific attention given to Experimental Autoimmune Encephalomyelitis (EAE), a rodent model of a chronic inflammatory disease of the CNS characterized by the formation of disseminated demyelinating lesions accompanied by axonal degeneration. Summary: We conclude that label-free nonlinear optical imaging combined to two photon imaging will continue to contribute richly to comprehend brain function and pathogenesis and to develop effective therapeutic strategies.
Collapse
Affiliation(s)
- Geneviève Rougon
- Aix-Marseille Université, CNRS, Institut des Neurosciences de la Timone, UMR 7289, Marseille, France
| | - Sophie Brasselet
- Aix-Marseille Université, CNRS, Centrale Marseille, Institut Fresnel, UMR 7249, Marseille, France
| | - Franck Debarbieux
- Aix-Marseille Université, CNRS, Institut des Neurosciences de la Timone, UMR 7289, Marseille, France
| |
Collapse
|
11
|
Exploring the Applicability of Nano-Poration for Remote Control in Smart Drug Delivery Systems. J Membr Biol 2016; 250:31-40. [PMID: 27561639 DOI: 10.1007/s00232-016-9922-1] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/20/2015] [Accepted: 08/16/2016] [Indexed: 12/25/2022]
Abstract
Smart drug delivery systems represent an interesting tool to significantly improve the efficiency and the precision in the treatment of a broad category of diseases. In this context, a drug delivery mediated by nanosecond pulsed electric fields seems a promising technique, allowing for a controlled release and uptake of drugs by the synergy between the electropulsation and nanocarriers with encapsulated drugs. The main concern about the use of electroporation for drug delivery applications is the difference in dimension between the liposome (nanometer range) and the cell (micrometer range). The choice of liposome dimension is not trivial. Liposomes larger than 500 nm of diameter could be recognized as pathogen agents by the immune system, while liposomes of smaller size would require external electric field of high amplitudes for the membrane electroporation that could compromise the cell viability. The aim of this work is to theoretically study the possibility of a simultaneous cell and liposomes electroporation. The numerical simulations reported the possibility to electroporate the cell and a significant percentage of liposomes with comparable values of external electric field, when a 12 nsPEF is used.
Collapse
|
12
|
Imaging of neuronal mitochondria in situ. Curr Opin Neurobiol 2016; 39:152-63. [PMID: 27454347 DOI: 10.1016/j.conb.2016.06.006] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/16/2016] [Revised: 06/04/2016] [Accepted: 06/07/2016] [Indexed: 11/21/2022]
Abstract
Neuronal mitochondria are receiving a rapidly increasing level of attention. This is to a significant part due to the ability to visualize neuronal mitochondria in novel ways, especially in vivo. Such an approach allows studying neuronal mitochondria in an intact tissue context, during different developmental states and in various genetic backgrounds and disease conditions. Hence, in vivo imaging of mitochondria in the nervous system can reveal aspects of the 'mitochondrial life cycle' in neurons that hitherto have remained obscure or could only be inferred indirectly. In this survey of the current literature, we review the new insights that have emerged from studies using mitochondrial imaging in intact neural preparations ranging from worms to mice.
Collapse
|
13
|
Gonzalez S, Berthelot J, Jiner J, Perrin-Tricaud C, Fernando R, Chrast R, Lenaers G, Tricaud N. Blocking mitochondrial calcium release in Schwann cells prevents demyelinating neuropathies. J Clin Invest 2016; 126:1023-38. [PMID: 26878172 DOI: 10.1172/jci84505] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2015] [Accepted: 12/18/2015] [Indexed: 02/06/2023] Open
Abstract
Schwann cells produce myelin sheath around peripheral nerve axons. Myelination is critical for rapid propagation of action potentials, as illustrated by the large number of acquired and hereditary peripheral neuropathies, such as diabetic neuropathy or Charcot-Marie-Tooth diseases, that are commonly associated with a process of demyelination. However, the early molecular events that trigger the demyelination program in these diseases remain unknown. Here, we used virally delivered fluorescent probes and in vivo time-lapse imaging in a mouse model of demyelination to investigate the underlying mechanisms of the demyelination process. We demonstrated that mitochondrial calcium released by voltage-dependent anion channel 1 (VDAC1) after sciatic nerve injury triggers Schwann cell demyelination via ERK1/2, p38, JNK, and c-JUN activation. In diabetic mice, VDAC1 activity was altered, resulting in a mitochondrial calcium leak in Schwann cell cytoplasm, thereby priming the cell for demyelination. Moreover, reduction of mitochondrial calcium release, either by shRNA-mediated VDAC1 silencing or pharmacological inhibition, prevented demyelination, leading to nerve conduction and neuromuscular performance recovery in rodent models of diabetic neuropathy and Charcot-Marie-Tooth diseases. Therefore, this study identifies mitochondria as the early key factor in the molecular mechanism of peripheral demyelination and opens a potential opportunity for the treatment of demyelinating peripheral neuropathies.
Collapse
|