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Guo YS, Bi X. Enriched environment enhanced the astrocyte-derived BDNF and VEGF expression and alleviate white matter injuries of rats with ischemic stroke. Neurol Res 2024; 46:272-283. [PMID: 38145566 DOI: 10.1080/01616412.2023.2298136] [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: 05/04/2023] [Accepted: 12/17/2023] [Indexed: 12/27/2023]
Abstract
OBJECTIVES Numerous studies have shown that an enriched environment can promote ischemic stroke and improve cognitive function. In addition, white matter is closely related to cognitive function. The effects and mechanisms of the enriched environment on white matter recovery after stroke have not been elucidated. This study will analyse the effects of the enriched environment on white matter and cognitive function in the post-stroke brain from the perspective of astrocytes and their secretions. METHODS Stroke models were used for middle cerebral artery occlusion model. post-operative rats were divided into sham-operated, standard and enriched environment groups. The degree of cerebral infarction was assessed by TTC staining and the degree of white matter damage was assessed by Luxol-Fast Blue staining. The prognosis after stroke was assessed using the longa score and Morris water maze test. Western Blot and immunofluorescence were used to quantify and localize astrocytes and their associated secretory factors and myelin protein markers. RESULTS We found that ischemic stroke can cause severe demyelination. After EE treatment, there was a significant increase in cerebral remyelination and a significant improvement in neurological and cognitive functions. Astrocyte, BDNF, and VEGF expression were significantly higher than in rats in the standard circumstances of stroke model. CONCLUSION These data suggest that the enriched environment contributes to brain white matter recovery and improvement of cognitive function after stroke. The mechanism is related to astrocytes and their secretions. EE can activate astrocytes to secrete BDNF and VEGF, which may be crucial to promote white matter recovery.
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Affiliation(s)
- Yi-Sha Guo
- Department of Physical Therapy, Affiliated Yangzhi Rehabilitation Hospital of Tongji University, Shanghai, China
- Department of rehabilitation medicine, Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
| | - Xia Bi
- Department of rehabilitation medicine, Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, China
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2
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Xiao J. Thirty years of BDNF study in central myelination: From biology to therapy. J Neurochem 2023; 167:321-336. [PMID: 37747083 DOI: 10.1111/jnc.15968] [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: 07/29/2023] [Revised: 09/05/2023] [Accepted: 09/07/2023] [Indexed: 09/26/2023]
Abstract
Being the highest expressed neurotrophin in the mammalian brain, the brain-derived neurotrophic factor (BDNF) is essential to neural development and plasticity in both health and diseases. Following the discovery of BDNF by Yves-Alain Barde in 1982, the main feature of BDNF's activity in myelination was first described by Cellerino et al. in 1997. Since then, genetic manipulation of the BDNF-encoding gene and its receptors in murine models has revealed the contribution of BDNF to the myelinating process in the central nervous system (CNS). The series of BDNF or receptor mouse mutants as well as the BDNF polymorphism in humans have provided new insights into the roles that BDNF signaling plays in myelination in a complex manner. 2024 marks the 30th year of BDNF's research in myelination. Here, we share our perspective on the 30-year history of BDNF in the field of CNS myelination from phenotyping to therapeutic development, focusing on genetic evidence regarding the mechanism by which BDNF regulates myelin formation and repair in the CNS. This review also discusses the current hypotheses of BDNF's action on CNS myelination: axonal- and oligodendroglial-driven mechanisms, which may be ultimately activity-dependent. Last, this review raises the challenges and opportunities of developing BDNF-based therapies for neurodegenerative diseases, opening unanswered questions for future investigation.
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Affiliation(s)
- Junhua Xiao
- School of Health Sciences, Swinburne University of Technology, Hawthorn, Victoria, Australia
- School of Allied Health, La Trobe University, Bundoora, Victoria, Australia
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3
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Jiang G, Ayaki T, Maki T, Yasuda K, Yoshii D, Kaji S, Takahashi R. Evaluation of BCAS1-positive immature oligodendrocytes after cerebral ischemic stroke and SVD. Neurosci Lett 2023; 812:137405. [PMID: 37479175 DOI: 10.1016/j.neulet.2023.137405] [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: 05/02/2023] [Revised: 07/02/2023] [Accepted: 07/18/2023] [Indexed: 07/23/2023]
Abstract
Ischemic cerebrovascular disease is an important cause of physical disability and dementia. Oligodendrocytes (OLGs), which differentiate from oligodendrocyte precursor cells (OPCs), are crucial for remyelination of the damaged brain and functional recovery. Breast carcinoma amplified sequence 1 (BCAS1) has recently been shown to be highly expressed in newly formed pre-myelinating oligodendrocytes (pre-mOLGs), while its expression level is reduced in mature OLGs. In this study, we analyzed BCAS1 expression by immunohistochemical analysis of human post-mortem brain tissue from six stroke patients (death within 2 months after stroke onset) and eight small vessel disease (SVD) patients. Control post-mortem brain tissue was from eight age-matched patients without any obvious central nervous system (CNS) pathology. The Olig2 expression in the area corresponding to the same section of the BCAS1-stained slice was analyzed to determine the total oligodendrocyte lineage. The percentage of differentiating OPCs in the oligodendrocyte lineage was calculated as the ratio of BCAS1+ to Olig2+ cells (BCAS1+/Olig2+). The stroke and SVD cases showed demyelination with decreased expression of myelin basic protein (MBP, a mature OLG marker). The stroke cases showed significantly increased numbers of early-stage BCAS1+ cells with an immature morphology and Olig2+ cells (pan-oligodendrocyte lineages) in the peri-infarct areas in both the cortex and white matter, but showed no increase in the number of late-stage BCAS1+ cells with a mature morphology. In contrast, the SVD cases showed no significant increase in Olig2+ and BCAS1+ cells. These results indicated that remyelination dysfunction could be attributed to insufficient maturation of OPCs in stroke and impaired recruitment of OPCs in SVD.
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Affiliation(s)
- Guanhua Jiang
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Takashi Ayaki
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan.
| | - Takakuni Maki
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ken Yasuda
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Daisuke Yoshii
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Seiji Kaji
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
| | - Ryosuke Takahashi
- Department of Neurology, Kyoto University Graduate School of Medicine, Kyoto, Japan
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4
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Rahman MM, Islam MR, Supti FA, Dhar PS, Shohag S, Ferdous J, Shuvo SK, Akter A, Hossain MS, Sharma R. Exploring the Therapeutic Effect of Neurotrophins and Neuropeptides in Neurodegenerative Diseases: at a Glance. Mol Neurobiol 2023:10.1007/s12035-023-03328-5. [PMID: 37052791 DOI: 10.1007/s12035-023-03328-5] [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: 11/28/2022] [Accepted: 03/22/2023] [Indexed: 04/14/2023]
Abstract
Neurotrophins and neuropeptides are the essential regulators of peripheral nociceptive nerves that help to induce, sensitize, and maintain pain. Neuropeptide has a neuroprotective impact as it increases trophic support, regulates calcium homeostasis, and reduces excitotoxicity and neuroinflammation. In contrast, neurotrophins target neurons afflicted by ischemia, epilepsy, depression, and eating disorders, among other neuropsychiatric conditions. Neurotrophins are reported to inhibit neuronal death. Strategies maintained for "brain-derived neurotrophic factor (BDNF) therapies" are to upregulate BDNF levels using the delivery of protein and genes or compounds that target BDNF production and boosting BDNF signals by expanding with BDNF mimetics. This review discusses the mechanisms of neurotrophins and neuropeptides against acute neural damage as well as highlighting neuropeptides as a potential therapeutic agent against Parkinson's disease (PD), Huntington's disease (HD), Alzheimer's disease (AD), and Machado-Joseph disease (MJD), the signaling pathways affected by neurotrophins and their receptors in both standard and diseased CNS systems, and future perspectives that can lead to the potent application of neurotrophins and neuropeptides in neurodegenerative diseases (NDs).
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Affiliation(s)
- Md Mominur Rahman
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, 1207, Bangladesh
| | - Md Rezaul Islam
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, 1207, Bangladesh
| | - Fatema Akter Supti
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, 1207, Bangladesh
| | - Puja Sutro Dhar
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, 1207, Bangladesh
| | - Sheikh Shohag
- Department of Genetic Engineering and Biotechnology, Faculty of Earth and Ocean Science, Bangabandhu Sheikh Mujibur Rahman Maritime University, Mirpur 12, Dhaka, 1216, Bangladesh
| | - Jannatul Ferdous
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, 1207, Bangladesh
| | - Shakil Khan Shuvo
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, 1207, Bangladesh
| | - Aklima Akter
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, 1207, Bangladesh
| | - Md Sarowar Hossain
- Department of Pharmacy, Faculty of Allied Health Sciences, Daffodil International University, Dhaka, 1207, Bangladesh
| | - Rohit Sharma
- Department of Rasa Shastra & Bhaishajya Kalpana, Faculty of Ayurveda, Institute of Medical Sciences, Banaras Hindu University, Varanasi, 221005, Uttar Pradesh, India.
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5
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Dyńka D, Kowalcze K, Paziewska A. The Role of Ketogenic Diet in the Treatment of Neurological Diseases. Nutrients 2022; 14:5003. [PMID: 36501033 PMCID: PMC9739023 DOI: 10.3390/nu14235003] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2022] [Revised: 11/20/2022] [Accepted: 11/21/2022] [Indexed: 11/26/2022] Open
Abstract
Over a hundred years of study on the favourable effect of ketogenic diets in the treatment of epilepsy have contributed to a long-lasting discussion on its potential influence on other neurological diseases. A significant increase in the number of scientific studies in that field has been currently observed. The aim of this paper is a widespread, thorough analysis of the available scientific evidence in respect of the role of the ketogenic diet in the therapy of neurological diseases such as: epilepsy, Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS) and migraine. A wide range of the mechanisms of action of the ketogenic diet has been demonstrated in neurological diseases, including, among other effects, its influence on the reduction in inflammatory conditions and the amount of reactive oxygen species (ROS), the restoration of the myelin sheath of the neurons, the formation and regeneration of mitochondria, neuronal metabolism, the provision of an alternative source of energy for neurons (ketone bodies), the reduction in glucose and insulin concentrations, the reduction in amyloid plaques, the induction of autophagy, the alleviation of microglia activation, the reduction in excessive neuronal activation, the modulation of intestinal microbiota, the expression of genes, dopamine production and the increase in glutamine conversion into GABA. The studies discussed (including randomised controlled studies), conducted in neurological patients, have stressed the effectiveness of the ketogenic diet in the treatment of epilepsy and have demonstrated its promising therapeutic potential in Alzheimer's disease (AD), Parkinson's disease (PD), multiple sclerosis (MS) and migraine. A frequent advantage of the diet was demonstrated over non-ketogenic diets (in the control groups) in the therapy of neurological diseases, with simultaneous safety and feasibility when conducting the nutritional model.
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Affiliation(s)
- Damian Dyńka
- Institute of Health Sciences, Faculty of Medical and Health Sciences, Siedlce University of Natural Sciences and Humanities, 08-110 Siedlce, Poland
| | - Katarzyna Kowalcze
- Institute of Health Sciences, Faculty of Medical and Health Sciences, Siedlce University of Natural Sciences and Humanities, 08-110 Siedlce, Poland
| | - Agnieszka Paziewska
- Institute of Health Sciences, Faculty of Medical and Health Sciences, Siedlce University of Natural Sciences and Humanities, 08-110 Siedlce, Poland
- Department of Neuroendocrinology, Centre of Postgraduate Medical Education, 01-813 Warsaw, Poland
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6
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Fekete CD, Nishiyama A. Presentation and integration of multiple signals that modulate oligodendrocyte lineage progression and myelination. Front Cell Neurosci 2022; 16:1041853. [PMID: 36451655 PMCID: PMC9701731 DOI: 10.3389/fncel.2022.1041853] [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: 09/11/2022] [Accepted: 10/17/2022] [Indexed: 11/15/2022] Open
Abstract
Myelination is critical for fast saltatory conduction of action potentials. Recent studies have revealed that myelin is not a static structure as previously considered but continues to be made and remodeled throughout adulthood in tune with the network requirement. Synthesis of new myelin requires turning on the switch in oligodendrocytes (OL) to initiate the myelination program that includes synthesis and transport of macromolecules needed for myelin production as well as the metabolic and other cellular functions needed to support this process. A significant amount of information is available regarding the individual intrinsic and extrinsic signals that promote OL commitment, expansion, terminal differentiation, and myelination. However, it is less clear how these signals are made available to OL lineage cells when needed, and how multiple signals are integrated to generate the correct amount of myelin that is needed in a given neural network state. Here we review the pleiotropic effects of some of the extracellular signals that affect myelination and discuss the cellular processes used by the source cells that contribute to the variation in the temporal and spatial availability of the signals, and how the recipient OL lineage cells might integrate the multiple signals presented to them in a manner dialed to the strength of the input.
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7
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Ketogenic and Modified Mediterranean Diet as a Tool to Counteract Neuroinflammation in Multiple Sclerosis: Nutritional Suggestions. Nutrients 2022; 14:nu14122384. [PMID: 35745113 PMCID: PMC9229939 DOI: 10.3390/nu14122384] [Citation(s) in RCA: 21] [Impact Index Per Article: 10.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2022] [Revised: 05/26/2022] [Accepted: 05/30/2022] [Indexed: 12/13/2022] Open
Abstract
Ketogenic Diet is a nutritional pattern often used as dietotherapy in inflammatory diseases, including neurological disorders. Applied on epileptic children since 1920, in recent years it has been taken into account again as a tool to both reduce inflammatory burdens and ameliorate the nutritional status of patients affected by different pathologies. Multiple sclerosis (MS) is considered an immune-mediated neuro-inflammatory disease and diet is a possible factor in its pathogenesis. The aim of this work is to investigate the main potential targets of MS-related impairments, in particular the cognitive deficits, focusing on the alteration of biomarkers such as the Brain Derived-Neurotrophic Factor and the Tryptophan/Kynurenine ratio that could play a role on neuroprotection and thus on MS progression. Furthermore, we here propose nutritional suggestions which are useful in the development of a ketogenic diet protocol that takes advantage of the anti-inflammatory properties of low-carbohydrate foods from the Mediterranean diet to be applied to subjects with MS. In conclusion, this approach will allow one to develop the ketogenic diet combined with a modified Mediterranean diet as a possible tool to improve neuroinflammation in multiple sclerosis.
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8
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Enriched Environment Effects on Myelination of the Central Nervous System: Role of Glial Cells. Neural Plast 2022; 2022:5766993. [PMID: 35465398 PMCID: PMC9023233 DOI: 10.1155/2022/5766993] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2021] [Revised: 01/20/2022] [Accepted: 03/09/2022] [Indexed: 12/24/2022] Open
Abstract
Myelination is regulated by various glial cells in the central nervous system (CNS), including oligodendrocytes (OLs), microglia, and astrocytes. Myelination of the CNS requires the generation of functionally mature OLs from OPCs. OLs are the myelin-forming cells in the CNS. Microglia play both beneficial and detrimental roles during myelin damage and repair. Astrocyte is responsible for myelin formation and regeneration by direct interaction with oligodendrocyte lineage cells. These glial cells are influenced by experience-dependent activities such as environmental enrichment (EE). To date, there are few studies that have investigated the association between EE and glial cells. EE with a complex combination of sensorimotor, cognitive, and social stimulation has a significant effect on cognitive impairment and brain plasticity. Hence, one mechanism through EE improving cognitive function may rely on the mutual effect of EE and glial cells. The purpose of this paper is to review recent research into the efficacy of EE for myelination and glial cells at cellular and molecular levels and offers critical insights for future research directions of EE and the treatment of EE in cognitive impairment disease.
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9
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Madhusudhan U, M K, Singaravelu V, Ganji V, John N, Gaur A. Brain-Derived Neurotrophic Factor-Mediated Cognitive Impairment in Hypothyroidism. Cureus 2022; 14:e23722. [PMID: 35506116 PMCID: PMC9056880 DOI: 10.7759/cureus.23722] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/31/2022] [Indexed: 11/16/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF), which is expressed at high levels in the limbic system, has been shown to regulate learning, memory and cognition. Thyroid hormone is crucial for brain development. Hypothyroidism is a clinical condition in which thyroid hormones are reduced and it affects the growth and development of the brain in neonates and progresses to cognitive impairment in adults. The exact mechanism of how reduced thyroid hormones impairs cognition and memory is not well understood. This review explores the possible role of BDNF-mediated cognitive impairment in hypothyroid patients.
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10
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Muzyka VV, Badea TC. Genetic interplay between transcription factor Pou4f1/Brn3a and neurotrophin receptor Ret in retinal ganglion cell type specification. Neural Dev 2021; 16:5. [PMID: 34548095 PMCID: PMC8454062 DOI: 10.1186/s13064-021-00155-z] [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: 04/19/2021] [Accepted: 08/05/2021] [Indexed: 12/15/2022] Open
Abstract
Background While the transcriptional code governing retinal ganglion cell (RGC) type specification begins to be understood, its interplay with neurotrophic signaling is largely unexplored. In mice, the transcription factor Brn3a/Pou4f1 is expressed in most RGCs, and is required for the specification of RGCs with small dendritic arbors. The Glial Derived Neurotrophic Factor (GDNF) receptor Ret is expressed in a subset of RGCs, including some expressing Brn3a, but its role in RGC development is not defined. Methods Here we use combinatorial genetic experiments using conditional knock-in reporter alleles at the Brn3a and Ret loci, in combination with retina- or Ret specific Cre drivers, to generate complete or mosaic genetic ablations of either Brn3a or Ret in RGCs. We then use sparse labelling to investigate Brn3a and Ret gene dosage effects on RGC dendritic arbor morphology. In addition, we use immunostaining and/or gene expression profiling by RNASeq to identify transcriptional targets relevant for the potential Brn3a-Ret interaction in RGC development. Results We find that mosaic gene dosage manipulation of the transcription factor Brn3a/Pou4f1 in neurotrophic receptor Ret heterozygote RGCs results in altered cell fate decisions and/or morphological dendritic defects. Specific RGC types are lost if Brn3a is ablated during embryogenesis and only mildly affected by postnatal Brn3a ablation. Sparse but not complete Brn3a heterozygosity combined with complete Ret heterozygosity has striking effects on RGC type distribution. Brn3a only mildly modulates Ret transcription, while Ret knockouts exhibit slightly skewed Brn3a and Brn3b expression during development that is corrected by adult age. Brn3a loss of function modestly but significantly affects distribution of Ret co-receptors GFRα1-3, and neurotrophin receptors TrkA and TrkC in RGCs. Conclusions Based on these observations, we propose that Brn3a and Ret converge onto developmental pathways that control RGC type specification, potentially through a competitive mechanism requiring signaling from the surrounding tissue. Supplementary Information The online version contains supplementary material available at 10.1186/s13064-021-00155-z.
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Affiliation(s)
- Vladimir Vladimirovich Muzyka
- Retinal Circuit Development & Genetics Unit, Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, NIH, Bethesda, MD, USA. .,Institute of Cytology and Genetics, Novosibirsk State University, Novosibirsk, Russia.
| | - Tudor Constantin Badea
- Retinal Circuit Development & Genetics Unit, Neurobiology-Neurodegeneration & Repair Laboratory, National Eye Institute, NIH, Bethesda, MD, USA. .,Research and Development Institute, School of Medicine, Transilvania University of Brasov, Brasov, Romania.
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11
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Schlecht A, Vallon M, Wagner N, Ergün S, Braunger BM. TGFβ-Neurotrophin Interactions in Heart, Retina, and Brain. Biomolecules 2021; 11:biom11091360. [PMID: 34572573 PMCID: PMC8464756 DOI: 10.3390/biom11091360] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2021] [Revised: 09/07/2021] [Accepted: 09/10/2021] [Indexed: 12/13/2022] Open
Abstract
Ischemic insults to the heart and brain, i.e., myocardial and cerebral infarction, respectively, are amongst the leading causes of death worldwide. While there are therapeutic options to allow reperfusion of ischemic myocardial and brain tissue by reopening obstructed vessels, mitigating primary tissue damage, post-infarction inflammation and tissue remodeling can lead to secondary tissue damage. Similarly, ischemia in retinal tissue is the driving force in the progression of neovascular eye diseases such as diabetic retinopathy (DR) and age-related macular degeneration (AMD), which eventually lead to functional blindness, if left untreated. Intriguingly, the easily observable retinal blood vessels can be used as a window to the heart and brain to allow judgement of microvascular damages in diseases such as diabetes or hypertension. The complex neuronal and endocrine interactions between heart, retina and brain have also been appreciated in myocardial infarction, ischemic stroke, and retinal diseases. To describe the intimate relationship between the individual tissues, we use the terms heart-brain and brain-retina axis in this review and focus on the role of transforming growth factor β (TGFβ) and neurotrophins in regulation of these axes under physiologic and pathologic conditions. Moreover, we particularly discuss their roles in inflammation and repair following ischemic/neovascular insults. As there is evidence that TGFβ signaling has the potential to regulate expression of neurotrophins, it is tempting to speculate, and is discussed here, that cross-talk between TGFβ and neurotrophin signaling protects cells from harmful and/or damaging events in the heart, retina, and brain.
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12
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Uccelli NA, Codagnone MG, Traetta ME, Levanovich N, Rosato Siri MV, Urrutia L, Falasco G, Vázquez S, Pasquini JM, Reinés AG. Neurobiological substrates underlying corpus callosum hypoconnectivity and brain metabolic patterns in the valproic acid rat model of autism spectrum disorder. J Neurochem 2021; 159:128-144. [PMID: 34081798 DOI: 10.1111/jnc.15444] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/14/2020] [Revised: 05/26/2021] [Accepted: 05/31/2021] [Indexed: 12/26/2022]
Abstract
Atypical connectivity between brain regions and altered structure of the corpus callosum (CC) in imaging studies supports the long-distance hypoconnectivity hypothesis proposed for autism spectrum disorder (ASD). The aim of this study was to unveil the CC ultrastructural and cellular changes employing the valproic acid (VPA) rat model of ASD. Male Wistar rats were exposed to VPA (450 mg/kg i.p.) or saline (control) during gestation (embryonic day 10.5), and maturation, exploration, and social behavior were subsequently tested. Myelin content, ultrastructure, and oligodendroglial lineage were studied in the CC at post-natal days 15 (infant) and 36 (juvenile). As a functional outcome, brain metabolic activity was determined by positron emission tomography. Concomitantly with behavioral deficits in juvenile VPA rats, the CC showed reduced myelin basic protein, conserved total number of axons, reduced percentage of myelinated axons, and aberrant and less compact arrangements of myelin sheath ultrastructure. Mature oligodendrocytes decreased and oligodendrocyte precursors increased in the absence of astrogliosis or microgliosis. In medial prefrontal and somatosensory cortices of juvenile VPA rats, myelin ultrastructure and oligodendroglial lineage were preserved. VPA animals exhibited global brain hypometabolism and local hypermetabolism in brain regions relevant for ASD. In turn, the CC of infant VPA rats showed reduced myelin content but preserved oligodendroglial lineage. Our findings indicate that CC hypomyelination is established during infancy and prior to oligodendroglial pattern alterations, which suggests that axon-oligodendroglia communication could be compromised in VPA animals. Thus, CC hypomyelination may underlie white matter alterations and contribute to atypical patterns of connectivity and metabolism found in ASD.
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Affiliation(s)
- Nonthué Alejandra Uccelli
- CONICET-Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN) Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Martín Gabriel Codagnone
- CONICET-Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN) Universidad de Buenos Aires, Buenos Aires, Argentina.,Departamento de Farmacología, Facultad de Farmacia y Bioquímica, Cátedra de Farmacología, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Marianela Evelyn Traetta
- CONICET-Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN) Universidad de Buenos Aires, Buenos Aires, Argentina.,Departamento de Farmacología, Facultad de Farmacia y Bioquímica, Cátedra de Farmacología, Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Nadia Levanovich
- Fundación para la lucha contra las enfermedades neurológicas de la infancia (FLENI), Centro de Imágenes Moleculares (CIM), Escobar, Argentina
| | - María Victoria Rosato Siri
- CONICET-Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológica (IQUIFIB) Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Leandro Urrutia
- Fundación para la lucha contra las enfermedades neurológicas de la infancia (FLENI), Centro de Imágenes Moleculares (CIM), Escobar, Argentina
| | - Germán Falasco
- Fundación para la lucha contra las enfermedades neurológicas de la infancia (FLENI), Centro de Imágenes Moleculares (CIM), Escobar, Argentina
| | - Silvia Vázquez
- Fundación para la lucha contra las enfermedades neurológicas de la infancia (FLENI), Centro de Imágenes Moleculares (CIM), Escobar, Argentina
| | - Juana María Pasquini
- CONICET-Universidad de Buenos Aires, Instituto de Química y Fisicoquímica Biológica (IQUIFIB) Universidad de Buenos Aires, Buenos Aires, Argentina
| | - Analía Gabriela Reinés
- CONICET-Universidad de Buenos Aires, Instituto de Biología Celular y Neurociencia "Prof. E. De Robertis" (IBCN) Universidad de Buenos Aires, Buenos Aires, Argentina.,Departamento de Farmacología, Facultad de Farmacia y Bioquímica, Cátedra de Farmacología, Universidad de Buenos Aires, Buenos Aires, Argentina
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13
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Guo YS, Yuan M, Han Y, Shen XY, Gao ZK, Bi X. Therapeutic Potential of Cytokines in Demyelinating Lesions After Stroke. J Mol Neurosci 2021; 71:2035-2052. [PMID: 33970426 DOI: 10.1007/s12031-021-01851-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 04/26/2021] [Indexed: 12/15/2022]
Abstract
White matter damage is a component of most human stroke and usually accounts for at least half of the lesion volume. Subcortical white matter stroke (WMS) accounts for 25% of all strokes and causes severe motor and cognitive dysfunction. The adult brain has a very limited ability to repair white matter damage. Pathological analysis shows that demyelination or myelin loss is the main feature of white matter injury and plays an important role in long-term sensorimotor and cognitive dysfunction. This suggests that demyelination is a major therapeutic target for ischemic stroke injury. An acute inflammatory reaction is triggered by brain ischemia, which is accompanied by cytokine production. The production of cytokines is an important factor affecting demyelination and myelin regeneration. Different cytokines have different effects on myelin damage and myelin regeneration. Exploring the role of cytokines in demyelination and remyelination after stroke and the underlying molecular mechanisms of demyelination and myelin regeneration after ischemic injury is very important for the development of rehabilitation treatment strategies. This review focuses on recent findings on the effects of cytokines on myelin damage and remyelination as well as the progress of research on the role of cytokines in ischemic stroke prognosis to provide a new treatment approach for amelioration of white matter damage after stroke.
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Affiliation(s)
- Yi-Sha Guo
- Shanghai University of Sport, Shanghai, 200438, China
| | - Mei Yuan
- Shanghai University of Sport, Shanghai, 200438, China
| | - Yu Han
- Shanghai University of Sport, Shanghai, 200438, China
| | - Xin-Ya Shen
- Shanghai University of Traditional Chinese Medicine, Shanghai, 200438, China
| | - Zhen-Kun Gao
- Shanghai University of Traditional Chinese Medicine, Shanghai, 200438, China
| | - Xia Bi
- Department of Rehabilitation Medicine, Shanghai University of Medicine & Health Sciences Affiliated Zhoupu Hospital, Shanghai, 201318, China.
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Neurotrophic Factors in Glaucoma and Innovative Delivery Systems. APPLIED SCIENCES-BASEL 2020. [DOI: 10.3390/app10249015] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Glaucoma is a neurodegenerative disease and a worldwide leading cause of irreversible vision loss. In the last decades, high efforts have been made to develop novel treatments effective in inducing protection and/or recovery of neural function in glaucoma, including neurotrophic factors (NTFs). These approaches have shown encouraging data in preclinical setting; however, the challenge of sustained, targeted delivery to the retina and optic nerve still prevents the clinical translation. In this paper, the authors review and discuss the most recent advances for the use of NTFs treatment in glaucoma, including intraocular delivery. Novel strategies in drug and gene delivery technology for NTFs are proving effective in promoting long-term retinal ganglion cells (RGCs) survival and related functional improvements. Results of experimental and clinical studies evaluating the efficacy and safety of biodegradable slow-release NTF-loaded microparticle devices, encapsulated NTF-secreting cells implants, mimetic ligands for NTF receptors, and viral and non-viral NTF gene vehicles are discussed. NTFs are able to prevent and even reverse apoptotic ganglion cell death. Nevertheless, neuroprotection in glaucoma remains an open issue due to the unmet need of sustained delivery to the posterior segment of the eye. The recent advances in intraocular delivery systems pave the way for possible future use of NTFs in clinical practice for the treatment of glaucoma.
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15
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Costa KCM, Brancaglion GA, Almeida CADF, de Amorim GES, Veloso LL, Lião LDS, de Souza GAP, Pinheiro BP, Ângelo ML, Ruginsk SG, Brandão WN, Marcourakis T, Ceron CS, Coelho LFL, Torres LH. No effect of prior Dengue virus 1 infection in mouse dams on long-term behavioral profiles in offspring infected with Zika virus during gestation. Neurosci Lett 2020; 739:135448. [PMID: 33129847 DOI: 10.1016/j.neulet.2020.135448] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2020] [Revised: 09/17/2020] [Accepted: 10/08/2020] [Indexed: 02/06/2023]
Abstract
Zika virus (ZIKV) is a mosquito-borne Flavivirus structurally and antigenically related to Dengue virus (DENV). Zika virus has been associated with congenital anomalies and most ZIKV outbreaks have occurred in endemic areas of DENV. The present study investigated the effects of prior DENV serotype 1 (DENV1) immunity in immunocompetent female Swiss mice on gestational ZIKV infection in offspring. Physical/reflex development, locomotor activity, anxiety, visual acuity, and brain-derived neurotrophic factor (BDNF) levels were evaluated in offspring during infancy and adolescence. Anti-DENV1 and anti-ZIKV antibodies were detected in sera of the progenitors, whereas no ZIKV genomes were detected in the offspring brain. Pups from dams with only DENV1 immunity presented alterations of physical/reflex development. Pups from all infected dams exhibited time-related impairments in locomotor activity and anxiolytic-like behavior. Offspring from DENV/ZIKV-infected dams exhibited impairments in visual acuity during infancy but not during adolescence, which was consistent with morphometric analysis of the optic nerve. Pups from DENV1-, ZIKV-, and DENV/ZIKV-infected dams exhibited a decrease in BDNF levels during infancy and an increase during adolescence in distinct brain regions. In summary, we found no influence of prior DENV1 immunity on gestational ZIKV infection in offspring, with the exception of alterations of early visual parameters, and an increase in BDNF levels in the hippocampus during adolescence.
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Affiliation(s)
- Karla Cristinne Mancini Costa
- Federal University of Alfenas, School of Pharmaceutical Sciences, Department of Food and Drugs, Alfenas, MG, CEP: 37130-000, Brazil
| | - Gustavo Andrade Brancaglion
- Federal University of Alfenas, Institute of Biomedical Sciences, Department of Microbiology and Immunology, Alfenas, MG, CEP: 37130-000, Brazil
| | | | - Gabriel Estevam Santos de Amorim
- Federal University of Alfenas, School of Pharmaceutical Sciences, Department of Food and Drugs, Alfenas, MG, CEP: 37130-000, Brazil
| | - Luciana Lopes Veloso
- Federal University of Alfenas, School of Pharmaceutical Sciences, Department of Food and Drugs, Alfenas, MG, CEP: 37130-000, Brazil
| | - Lucas da Silva Lião
- Federal University of Alfenas, School of Pharmaceutical Sciences, Department of Food and Drugs, Alfenas, MG, CEP: 37130-000, Brazil
| | - Gabriel Augusto Pires de Souza
- Federal University of Alfenas, Institute of Biomedical Sciences, Department of Microbiology and Immunology, Alfenas, MG, CEP: 37130-000, Brazil
| | - Bruna Pereira Pinheiro
- Federal University of Alfenas, School of Pharmaceutical Sciences, Department of Food and Drugs, Alfenas, MG, CEP: 37130-000, Brazil
| | - Marilene Lopes Ângelo
- Federal University of Alfenas, School of Pharmaceutical Sciences, Department of Food and Drugs, Alfenas, MG, CEP: 37130-000, Brazil
| | - Silvia Graciela Ruginsk
- Federal University of Alfenas, Institute of Biomedical Sciences, Department of Physiological Sciences, Alfenas, MG, CEP: 37130-000, Brazil
| | - Wesley Nogueira Brandão
- University of São Paulo, Institute of Biomedical Sciences, Department of Immunology, São Paulo, SP, CEP: 05508-000, Brazil
| | - Tania Marcourakis
- University of São Paulo, School of Pharmaceutical Sciences, Department of Clinical and Toxicological Analysis, São Paulo, SP, CEP: 05508-000, Brazil
| | - Carla Speroni Ceron
- Federal University of Alfenas, School of Pharmaceutical Sciences, Department of Food and Drugs, Alfenas, MG, CEP: 37130-000, Brazil
| | - Luiz Felipe Leomil Coelho
- Federal University of Alfenas, Institute of Biomedical Sciences, Department of Microbiology and Immunology, Alfenas, MG, CEP: 37130-000, Brazil
| | - Larissa Helena Torres
- Federal University of Alfenas, School of Pharmaceutical Sciences, Department of Food and Drugs, Alfenas, MG, CEP: 37130-000, Brazil.
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16
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Craig GA, Yoo S, Du TY, Xiao J. Plasticity in oligodendrocyte lineage progression: An OPC puzzle on our nerves. Eur J Neurosci 2020; 54:5747-5761. [PMID: 32478920 DOI: 10.1111/ejn.14845] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/02/2020] [Revised: 05/20/2020] [Accepted: 05/21/2020] [Indexed: 11/28/2022]
Abstract
Myelin deposition in the central nervous system has been shown to be responsive to experience, with sensory enrichment increasing myelination and sensory or social deprivation decreasing myelination. This process is referred to as "adaptive myelination" or "myelin plasticity" and signifies an essential component of new learning. However, whether these experience-driven adaptations are driven by (a) underlying changes in the generation of myelinating cells, (b) altered interactions between myelin sheath and axon, or (c) a combination of the above remains unclear. It has been suggested that myelination largely follows an "innate" and automatic programme, allowing for a predictable pattern of central nervous system myelin deposition over time. Adaptive myelination is thought to account for more nuanced alterations that do not dramatically shift this pattern, but ultimately drive functional responses. This makes the study of myelin plasticity particularly difficult, as it necessitates being able to clearly and specifically draw boundaries between the innate and adaptive programme. Thus, the field requires a holistic understanding of the remit of innate myelin development, prior to investigation of adaptive myelination. This review will collate literature regarding different aspects of oligodendrocyte and myelin development (namely, oligodendrocyte proliferation, differentiation, death and myelin sheath formation) in an innate context, before discussing how these parameters are proposed to change under adaptive conditions. It is the hope that this review will highlight the need for a comprehensive and integrated approach towards studying both innate and adaptive forms of myelination.
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Affiliation(s)
- Georgina A Craig
- Department of Anatomy and Neuroscience, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Vic., Australia
| | - SangWon Yoo
- Department of Anatomy and Neuroscience, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Vic., Australia
| | - Tian Y Du
- Department of Anatomy and Neuroscience, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Vic., Australia
| | - Junhua Xiao
- Department of Anatomy and Neuroscience, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Vic., Australia
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17
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Roles of Progesterone, Testosterone and Their Nuclear Receptors in Central Nervous System Myelination and Remyelination. Int J Mol Sci 2020; 21:ijms21093163. [PMID: 32365806 PMCID: PMC7246940 DOI: 10.3390/ijms21093163] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2020] [Revised: 04/27/2020] [Accepted: 04/28/2020] [Indexed: 12/14/2022] Open
Abstract
Progesterone and testosterone, beyond their roles as sex hormones, are neuroactive steroids, playing crucial regulatory functions within the nervous system. Among these, neuroprotection and myelin regeneration are important ones. The present review aims to discuss the stimulatory effects of progesterone and testosterone on the process of myelination and remyelination. These effects have been demonstrated in vitro (i.e., organotypic cultures) and in vivo (cuprizone- or lysolecithin-induced demyelination and experimental autoimmune encephalomyelitis (EAE)). Both steroids stimulate myelin formation and regeneration by acting through their respective intracellular receptors: progesterone receptors (PR) and androgen receptors (AR). Activation of these receptors results in multiple events involving direct transcription and translation, regulating general homeostasis, cell proliferation, differentiation, growth and myelination. It also ameliorates immune response as seen in the EAE model, resulting in a significant decrease in inflammation leading to a fast recovery. Although natural progesterone and testosterone have a therapeutic potential, their synthetic derivatives—the 19-norprogesterone (nestorone) and 7α-methyl-nortestosterone (MENT), already used as hormonal contraception or in postmenopausal hormone replacement therapies, may offer enhanced benefits for myelin repair. We summarize here a recent advancement in the field of myelin biology, to treat demyelinating disorders using the natural as well as synthetic analogs of progesterone and testosterone.
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18
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Traiffort E, Kassoussi A, Zahaf A, Laouarem Y. Astrocytes and Microglia as Major Players of Myelin Production in Normal and Pathological Conditions. Front Cell Neurosci 2020; 14:79. [PMID: 32317939 PMCID: PMC7155218 DOI: 10.3389/fncel.2020.00079] [Citation(s) in RCA: 101] [Impact Index Per Article: 25.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2019] [Accepted: 03/19/2020] [Indexed: 12/13/2022] Open
Abstract
Myelination is an essential process that consists of the ensheathment of axons by myelin. In the central nervous system (CNS), myelin is synthesized by oligodendrocytes. The proliferation, migration, and differentiation of oligodendrocyte precursor cells constitute a prerequisite before mature oligodendrocytes extend their processes around the axons and progressively generate a multilamellar lipidic sheath. Although myelination is predominately driven by oligodendrocytes, the other glial cells including astrocytes and microglia, also contribute to this process. The present review is an update of the most recent emerging mechanisms involving astrocyte and microglia in myelin production. The contribution of these cells will be first described during developmental myelination that occurs in the early postnatal period and is critical for the proper development of cognition and behavior. Then, we will report the novel findings regarding the beneficial or deleterious effects of astroglia and microglia, which respectively promote or impair the endogenous capacity of oligodendrocyte progenitor cells (OPCs) to induce spontaneous remyelination after myelin loss. Acute delineation of astrocyte and microglia activities and cross-talk should uncover the way towards novel therapeutic perspectives aimed at recovering proper myelination during development or at breaking down the barriers impeding the regeneration of the damaged myelin that occurs in CNS demyelinating diseases.
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Affiliation(s)
| | | | - Amina Zahaf
- U1195 Inserm, University Paris-Saclay, Kremlin-Bicêtre, France
| | - Yousra Laouarem
- U1195 Inserm, University Paris-Saclay, Kremlin-Bicêtre, France
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19
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Göttle P, Förster M, Weyers V, Küry P, Rejdak K, Hartung HP, Kremer D. An unmet clinical need: roads to remyelination in MS. Neurol Res Pract 2019; 1:21. [PMID: 33324887 PMCID: PMC7650135 DOI: 10.1186/s42466-019-0026-0] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/11/2019] [Accepted: 05/14/2019] [Indexed: 12/15/2022] Open
Abstract
Background In the central nervous system (CNS) myelin sheaths stabilize, protect, and electrically insulate axons. However, in demyelinating autoimmune CNS diseases such as multiple sclerosis (MS) these sheaths are destroyed which ultimately leads to neurodegeneration. The currently available immunomodulatory drugs for MS effectively control the (auto)inflammatory facets of the disease but are unable to regenerate myelin by stimulating remyelination via oligodendroglial precursor cells (OPCs). Accordingly, there is broad consensus that the implementation of new regenerative approaches constitutes the prime goal for future MS pharmacotherapy. Main text Of note, recent years have seen several promising clinical studies investigating the potential of substances and monoclonal antibodies such as, for instance, clemastine, opicinumab, biotin, simvastatin, quetiapin and anti-GNbAC1. However, beyond these agents which have often been re-purposed from other medical indications there is a multitude of further molecules influencing OPC homeostasis. Here, we therefore discuss these possibly beneficial regulators of OPC differentiation and assess their potential as new pharmacological targets for myelin repair in MS. Conclusion Remyelination remains the most important therapeutic treatment goal in MS in order to improve clinical deficits and to avert neurodegeneration. The promising molecules presented in this review have the potential to promote remyelination and therefore warrant further translational and clinical research.
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Affiliation(s)
- Peter Göttle
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Moritz Förster
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Vivien Weyers
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Patrick Küry
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - Konrad Rejdak
- Department of Neurology, Medical University of Lublin, Lublin, Poland
| | - Hans-Peter Hartung
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
| | - David Kremer
- Department of Neurology, Medical Faculty, Heinrich-Heine-University, Moorenstrasse 5, 40225 Düsseldorf, Germany
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20
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Geraghty AC, Gibson EM, Ghanem RA, Greene JJ, Ocampo A, Goldstein AK, Ni L, Yang T, Marton RM, Paşca SP, Greenberg ME, Longo FM, Monje M. Loss of Adaptive Myelination Contributes to Methotrexate Chemotherapy-Related Cognitive Impairment. Neuron 2019; 103:250-265.e8. [PMID: 31122677 DOI: 10.1016/j.neuron.2019.04.032] [Citation(s) in RCA: 148] [Impact Index Per Article: 29.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2018] [Revised: 01/29/2019] [Accepted: 04/22/2019] [Indexed: 01/05/2023]
Abstract
Activity-dependent myelination is thought to contribute to adaptive neurological function. However, the mechanisms by which activity regulates myelination and the extent to which myelin plasticity contributes to non-motor cognitive functions remain incompletely understood. Using a mouse model of chemotherapy-related cognitive impairment (CRCI), we recently demonstrated that methotrexate (MTX) chemotherapy induces complex glial dysfunction for which microglial activation is central. Here, we demonstrate that remote MTX exposure blocks activity-regulated myelination. MTX decreases cortical Bdnf expression, which is restored by microglial depletion. Bdnf-TrkB signaling is a required component of activity-dependent myelination. Oligodendrocyte precursor cell (OPC)-specific TrkB deletion in chemotherapy-naive mice results in impaired cognitive behavioral performance. A small-molecule TrkB agonist rescues both myelination and cognitive impairment after MTX chemotherapy. This rescue after MTX depends on intact TrkB expression in OPCs. Taken together, these findings demonstrate a molecular mechanism required for adaptive myelination that is aberrant in CRCI due to microglial activation.
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Affiliation(s)
- Anna C Geraghty
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Erin M Gibson
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Reem A Ghanem
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Jacob J Greene
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Alfonso Ocampo
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Andrea K Goldstein
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Lijun Ni
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Tao Yang
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Rebecca M Marton
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | - Sergiu P Paşca
- Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA
| | | | - Frank M Longo
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA
| | - Michelle Monje
- Department of Neurology and Neurological Sciences, Stanford University, Stanford, CA 94305, USA; Department of Psychiatry and Behavioral Sciences, Stanford University, Stanford, CA 94305, USA; Department of Pathology, Stanford University, Stanford, CA 94305, USA; Department of Pediatrics, Stanford University, Stanford, CA 94305, USA; Institute for Stem Cell Biology and Regenerative Medicine, Stanford University, Stanford, CA 94305, USA.
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21
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Pöyhönen S, Er S, Domanskyi A, Airavaara M. Effects of Neurotrophic Factors in Glial Cells in the Central Nervous System: Expression and Properties in Neurodegeneration and Injury. Front Physiol 2019; 10:486. [PMID: 31105589 PMCID: PMC6499070 DOI: 10.3389/fphys.2019.00486] [Citation(s) in RCA: 139] [Impact Index Per Article: 27.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2018] [Accepted: 04/08/2019] [Indexed: 12/28/2022] Open
Abstract
Astrocytes, oligodendrocytes, and microglia are abundant cell types found in the central nervous system and have been shown to play crucial roles in regulating both normal and disease states. An increasing amount of evidence points to the critical importance of glia in mediating neurodegeneration in Alzheimer’s and Parkinson’s diseases (AD, PD), and in ischemic stroke, where microglia are involved in initial tissue clearance, and astrocytes in the subsequent formation of a glial scar. The importance of these cells for neuronal survival has previously been studied in co-culture experiments and the search for neurotrophic factors (NTFs) initiated after finding that the addition of conditioned media from astrocyte cultures could support the survival of primary neurons in vitro. This led to the discovery of the potent dopamine neurotrophic factor, glial cell line-derived neurotrophic factor (GDNF). In this review, we focus on the relationship between glia and NTFs including neurotrophins, GDNF-family ligands, CNTF family, and CDNF/MANF-family proteins. We describe their expression in astrocytes, oligodendrocytes and their precursors (NG2-positive cells, OPCs), and microglia during development and in the adult brain. Furthermore, we review existing data on the glial phenotypes of NTF knockout mice and follow NTF expression patterns and their effects on glia in disease models such as AD, PD, stroke, and retinal degeneration.
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Affiliation(s)
- Suvi Pöyhönen
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Safak Er
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Andrii Domanskyi
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland
| | - Mikko Airavaara
- Institute of Biotechnology, HiLIFE, University of Helsinki, Helsinki, Finland.,Neuroscience Center, HiLIFE, University of Helsinki, Helsinki, Finland
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22
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Fletcher JL, Murray SS, Xiao J. Brain-Derived Neurotrophic Factor in Central Nervous System Myelination: A New Mechanism to Promote Myelin Plasticity and Repair. Int J Mol Sci 2018; 19:ijms19124131. [PMID: 30572673 PMCID: PMC6321406 DOI: 10.3390/ijms19124131] [Citation(s) in RCA: 68] [Impact Index Per Article: 11.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2018] [Revised: 12/18/2018] [Accepted: 12/18/2018] [Indexed: 12/27/2022] Open
Abstract
Brain-derived neurotrophic factor (BDNF) plays vitally important roles in neural development and plasticity in both health and disease. Recent studies using mutant mice to selectively manipulate BDNF signalling in desired cell types, in combination with animal models of demyelinating disease, have demonstrated that BDNF not only potentiates normal central nervous system myelination in development but enhances recovery after myelin injury. However, the precise mechanisms by which BDNF enhances myelination in development and repair are unclear. Here, we review some of the recent progress made in understanding the influence BDNF exerts upon the myelinating process during development and after injury, and discuss the cellular and molecular mechanisms underlying its effects. In doing so, we raise new questions for future research.
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Affiliation(s)
- Jessica L Fletcher
- Department of Anatomy and Neuroscience, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, 3010, VIC, Australia.
| | - Simon S Murray
- Department of Anatomy and Neuroscience, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, 3010, VIC, Australia.
| | - Junhua Xiao
- Department of Anatomy and Neuroscience, School of Biomedical Sciences, Faculty of Medicine, Dentistry and Health Sciences, The University of Melbourne, Parkville, 3010, VIC, Australia.
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23
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Rabesandratana O, Goureau O, Orieux G. Pluripotent Stem Cell-Based Approaches to Explore and Treat Optic Neuropathies. Front Neurosci 2018; 12:651. [PMID: 30294255 PMCID: PMC6158340 DOI: 10.3389/fnins.2018.00651] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/24/2018] [Accepted: 08/30/2018] [Indexed: 12/15/2022] Open
Abstract
Sight is a major sense for human and visual impairment profoundly affects quality of life, especially retinal degenerative diseases which are the leading cause of irreversible blindness worldwide. As for other neurodegenerative disorders, almost all retinal dystrophies are characterized by the specific loss of one or two cell types, such as retinal ganglion cells, photoreceptor cells, or retinal pigmented epithelial cells. This feature is a critical point when dealing with cell replacement strategies considering that the preservation of other cell types and retinal circuitry is a prerequisite. Retinal ganglion cells are particularly vulnerable to degenerative process and glaucoma, the most common optic neuropathy, is a frequent retinal dystrophy. Cell replacement has been proposed as a potential approach to take on the challenge of visual restoration, but its application to optic neuropathies is particularly challenging. Many obstacles need to be overcome before any clinical application. Beyond their survival and differentiation, engrafted cells have to reconnect with both upstream synaptic retinal cell partners and specific targets in the brain. To date, reconnection of retinal ganglion cells with distal central targets appears unrealistic since central nervous system is refractory to regenerative processes. Significant progress on the understanding of molecular mechanisms that prevent central nervous system regeneration offer hope to overcome this obstacle in the future. At the same time, emergence of reprogramming of human somatic cells into pluripotent stem cells has facilitated both the generation of new source of cells with therapeutic potential and the development of innovative methods for the generation of transplantable cells. In this review, we discuss the feasibility of stem cell-based strategies applied to retinal ganglion cells and optic nerve impairment. We present the different strategies for the generation, characterization and the delivery of transplantable retinal ganglion cells derived from pluripotent stem cells. The relevance of pluripotent stem cell-derived retinal organoid and retinal ganglion cells for disease modeling or drug screening will be also introduced in the context of optic neuropathies.
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Affiliation(s)
| | - Olivier Goureau
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
| | - Gaël Orieux
- Sorbonne Université, INSERM, CNRS, Institut de la Vision, Paris, France
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24
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Targeting TrkB with a Brain-Derived Neurotrophic Factor Mimetic Promotes Myelin Repair in the Brain. J Neurosci 2018; 38:7088-7099. [PMID: 29976621 DOI: 10.1523/jneurosci.0487-18.2018] [Citation(s) in RCA: 49] [Impact Index Per Article: 8.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 06/01/2018] [Accepted: 06/25/2018] [Indexed: 12/22/2022] Open
Abstract
Methods to promote myelin regeneration in response to central myelin loss are essential to prevent the progression of clinical disability in demyelinating diseases. The neurotrophin brain-derived neurotrophic factor (BDNF) is known to promote myelination during development via oligodendrocyte expressed TrkB receptors. Here, we use a structural mimetic of BDNF to promote myelin regeneration in a preclinical mouse model of central demyelination. In female mice, we show that selective targeting of TrkB with the BDNF-mimetic enhances remyelination, increasing oligodendrocyte differentiation, the frequency of myelinated axons, and myelin sheath thickness after a demyelinating insult. Treatment with exogenous BDNF exerted an attenuated effect, increasing myelin sheath thickness only. Further, following conditional deletion of TrkB from premyelinating oligodendrocytes, we show the effects of the BDNF-mimetic on oligodendrocyte differentiation and remyelination are lost, indicating these are dependent on oligodendrocyte expression of TrkB. Overall, these studies demonstrate that targeting oligodendrocyte TrkB promotes in vivo remyelination in the brain.SIGNIFICANCE STATEMENT Novel strategies to promote myelin regeneration are required to prevent progressive neurodegeneration and clinical disability in patients with central demyelinating disease. Here, we test whether selectively targeting the TrkB receptor on the myelin-producing oligodendrocytes, can promote remyelination in the brain. Using a structural mimetic of its native ligand, BDNF, we show that stimulation of TrkB enhances remyelination, increasing oligodendrocyte differentiation, the frequency of myelinated axons and thickness of the myelin sheath following a demyelinating insult. Further, we show that these effects are dependent on the phosphorylation of oligodendrocyte expressed TrkB receptors in vivo Overall, we demonstrate that selective targeting of TrkB has therapeutic potential to promote remyelination in the brain.
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Yap TE, Donna P, Almonte MT, Cordeiro MF. Real-Time Imaging of Retinal Ganglion Cell Apoptosis. Cells 2018; 7:E60. [PMID: 29914056 PMCID: PMC6025611 DOI: 10.3390/cells7060060] [Citation(s) in RCA: 26] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/09/2018] [Revised: 06/06/2018] [Accepted: 06/14/2018] [Indexed: 02/07/2023] Open
Abstract
Monitoring real-time apoptosis in-vivo is an unmet need of neurodegeneration science, both in clinical and research settings. For patients, earlier diagnosis before the onset of symptoms provides a window of time in which to instigate treatment. For researchers, being able to objectively monitor the rates of underlying degenerative processes at a cellular level provides a biomarker with which to test novel therapeutics. The DARC (Detection of Apoptosing Retinal Cells) project has developed a minimally invasive method using fluorescent annexin A5 to detect rates of apoptosis in retinal ganglion cells, the key pathological process in glaucoma. Numerous animal studies have used DARC to show efficacy of novel, pressure-independent treatment strategies in models of glaucoma and other conditions where retinal apoptosis is reported, including Alzheimer’s disease. This may forge exciting new links in the clinical science of treating both cognitive and visual decline. Human trials are now underway, successfully demonstrating the safety and efficacy of the technique to differentiate patients with progressive neurodegeneration from healthy individuals. We review the current perspectives on retinal ganglion cell apoptosis, the way in which this can be imaged, and the exciting advantages that these future methods hold in store.
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Affiliation(s)
- Timothy E Yap
- The Western Eye Hospital, Imperial College Healthcare NHS Trust (ICHNT), London NW1 5QH, UK.
- The Imperial College Ophthalmic Research Group (ICORG), Imperial College London, London NW1 5QH, UK.
| | - Piero Donna
- The Imperial College Ophthalmic Research Group (ICORG), Imperial College London, London NW1 5QH, UK.
| | - Melanie T Almonte
- The Imperial College Ophthalmic Research Group (ICORG), Imperial College London, London NW1 5QH, UK.
| | - Maria Francesca Cordeiro
- The Western Eye Hospital, Imperial College Healthcare NHS Trust (ICHNT), London NW1 5QH, UK.
- The Imperial College Ophthalmic Research Group (ICORG), Imperial College London, London NW1 5QH, UK.
- Glaucoma and Retinal Neurodegeneration Group, Department of Visual Neuroscience, UCL Institute of Ophthalmology, London EC1V 9EL, UK.
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To Be or Not to Be: Environmental Factors that Drive Myelin Formation during Development and after CNS Trauma. ACTA ACUST UNITED AC 2018. [DOI: 10.3390/neuroglia1010007] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Oligodendrocytes are specialized glial cells that myelinate central nervous system (CNS) axons. Historically, it was believed that the primary role of myelin was to compactly ensheath axons, providing the insulation necessary for rapid signal conduction. However, mounting evidence demonstrates the dynamic importance of myelin and oligodendrocytes, including providing metabolic support to neurons and regulating axon protein distribution. As such, the development and maintenance of oligodendrocytes and myelin are integral to preserving CNS homeostasis and supporting proper functioning of widespread neural networks. Environmental signals are critical for proper oligodendrocyte lineage cell progression and their capacity to form functional compact myelin; these signals are markedly disturbed by injury to the CNS, which may compromise endogenous myelin repair capabilities. This review outlines some key environmental factors that drive myelin formation during development and compares that to the primary factors that define a CNS injury milieu. We aim to identify developmental factors disrupted after CNS trauma as well as pathogenic factors that negatively impact oligodendrocyte lineage cells, as these are potential therapeutic targets to promote myelin repair after injury or disease.
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Nicholson M, Wood RJ, Fletcher JL, van den Buuse M, Murray SS, Xiao J. BDNF haploinsufficiency exerts a transient and regionally different influence upon oligodendroglial lineage cells during postnatal development. Mol Cell Neurosci 2018; 90:12-21. [PMID: 29782918 DOI: 10.1016/j.mcn.2018.05.005] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2017] [Revised: 05/09/2018] [Accepted: 05/15/2018] [Indexed: 01/19/2023] Open
Abstract
Brain-Derived Neurotrophic Factor (BDNF) plays important roles in promoting myelination in the developing central nervous system (CNS), however the influence it exerts on oligodendrocyte development in vivo remains unclear. As BDNF knockout mice die in the perinatal period, we undertook a systematic developmental analysis of oligodendroglial lineage cells within multiple CNS regions of BDNF heterozygous (HET) mice. Our data identify that BDNF heterozygosity results in transient reductions in oligodendroglial lineage cell density and progression that are largely restricted to the optic nerve, whereas the corpus callosum, cerebral cortex, basal forebrain and spinal cord white matter tracts are unaffected. In the first two postnatal weeks, BDNF HET mice exhibit reductions in the density of oligodendroglial lineage cells, oligodendrocyte precursor cells (OPCs) and postmitotic oligodendrocytes selectively in the optic nerve, but not in the brain or spinal cord white matter tracts. However, this normalizes later in development. The overall proportion of OPCs and mature oligodendrocytes remains unchanged from P9 to P30 in all CNS regions. This study identifies that BDNF exerts transient effects on oligodendroglial lineage cells selectively in the optic nerve during postnatal development. Taken together, this provides compelling evidence that BDNF haploinsufficiency exerts modest effects upon oligodendroglial cell density and lineage progression in vivo, suggesting its major role is restricted to promoting oligodendrocyte myelination.
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Affiliation(s)
- Madeline Nicholson
- Department of Anatomy and Neuroscience, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Rhiannon J Wood
- Department of Anatomy and Neuroscience, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Jessica L Fletcher
- Department of Anatomy and Neuroscience, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Maarten van den Buuse
- School of Psychology and Public Health, La Trobe University, Bundoora, Victoria 3086, Australia; Department of Pharmacology, University of Melbourne, Victoria 3010, Australia; The College of Public Health, Medical and Veterinary Sciences, James Cook University, Townsville, Queensland 4811, Australia
| | - Simon S Murray
- Department of Anatomy and Neuroscience, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria 3010, Australia; The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3010, Australia
| | - Junhua Xiao
- Department of Anatomy and Neuroscience, Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Victoria 3010, Australia; The Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Victoria 3010, Australia.
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Bechler ME, Swire M, ffrench‐Constant C. Intrinsic and adaptive myelination-A sequential mechanism for smart wiring in the brain. Dev Neurobiol 2018; 78:68-79. [PMID: 28834358 PMCID: PMC5813148 DOI: 10.1002/dneu.22518] [Citation(s) in RCA: 83] [Impact Index Per Article: 13.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/12/2017] [Revised: 07/28/2017] [Accepted: 08/19/2017] [Indexed: 12/15/2022]
Abstract
The concept of adaptive myelination-myelin plasticity regulated by activity-is an important advance for the field. What signals set up the adaptable pattern in the first place? Here we review work that demonstrates an intrinsic pathway within oligodendrocytes requiring only an axon-shaped substrate to generate multilayered and compacted myelin sheaths of a physiological length. Based on this, we discuss a model we proposed in 2015 which argues that myelination has two phases-intrinsic and then adaptive-which together generate "smart wiring," in which active axons become more myelinated. This model explains why prior studies have failed to identify a signal necessary for central nervous system myelination and argues that myelination, like synapses, might contribute to learning by the activity-dependent modification of an initially hard-wired pattern. © 2017 The Authors. Developmental Neurobiology Published by Wiley Periodicals, Inc. Develop Neurobiol 78: 68-79, 2018.
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Affiliation(s)
- Marie E. Bechler
- MRC Centre for Regenerative Medicine and MS Society Edinburgh Centre for MS Research, The University of Edinburgh, 5 Little France DriveEdinburghEH16 4UUUnited Kingdom
| | - Matthew Swire
- MRC Centre for Regenerative Medicine and MS Society Edinburgh Centre for MS Research, The University of Edinburgh, 5 Little France DriveEdinburghEH16 4UUUnited Kingdom
| | - Charles ffrench‐Constant
- MRC Centre for Regenerative Medicine and MS Society Edinburgh Centre for MS Research, The University of Edinburgh, 5 Little France DriveEdinburghEH16 4UUUnited Kingdom
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Figlia G, Gerber D, Suter U. Myelination and mTOR. Glia 2017; 66:693-707. [PMID: 29210103 PMCID: PMC5836902 DOI: 10.1002/glia.23273] [Citation(s) in RCA: 109] [Impact Index Per Article: 15.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2017] [Revised: 11/08/2017] [Accepted: 11/17/2017] [Indexed: 02/06/2023]
Abstract
Myelinating cells surround axons to accelerate the propagation of action potentials, to support axonal health, and to refine neural circuits. Myelination is metabolically demanding and, consistent with this notion, mTORC1—a signaling hub coordinating cell metabolism—has been implicated as a key signal for myelination. Here, we will discuss metabolic aspects of myelination, illustrate the main metabolic processes regulated by mTORC1, and review advances on the role of mTORC1 in myelination of the central nervous system and the peripheral nervous system. Recent progress has revealed a complex role of mTORC1 in myelinating cells that includes, besides positive regulation of myelin growth, additional critical functions in the stages preceding active myelination. Based on the available evidence, we will also highlight potential nonoverlapping roles between mTORC1 and its known main upstream pathways PI3K‐Akt, Mek‐Erk1/2, and AMPK in myelinating cells. Finally, we will discuss signals that are already known or hypothesized to be responsible for the regulation of mTORC1 activity in myelinating cells. Myelination is metabolically demanding. The metabolic regulator mTORC1 controls differentiation of myelinating cells and promotes myelin
growth. mTORC1‐independent targets of the PI3K‐Akt and Mek‐Erk1/2 pathways may also be significant in myelination.
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Affiliation(s)
- Gianluca Figlia
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, CH 8093, Switzerland
| | - Daniel Gerber
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, CH 8093, Switzerland
| | - Ueli Suter
- Institute of Molecular Health Sciences, Department of Biology, Swiss Federal Institute of Technology, ETH Zürich, Zürich, CH 8093, Switzerland
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Zhou T, Ahmad TK, Gozda K, Truong J, Kong J, Namaka M. Implications of white matter damage in amyotrophic lateral sclerosis (Review). Mol Med Rep 2017; 16:4379-4392. [PMID: 28791401 PMCID: PMC5646997 DOI: 10.3892/mmr.2017.7186] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2017] [Accepted: 06/09/2017] [Indexed: 12/11/2022] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease, which involves the progressive degeneration of motor neurons. ALS has long been considered a disease of the grey matter; however, pathological alterations of the white matter (WM), including axonal loss, axonal demyelination and oligodendrocyte death, have been reported in patients with ALS. The present review examined motor neuron death as the primary cause of ALS and evaluated the associated WM damage that is guided by neuronal‑glial interactions. Previous studies have suggested that WM damage may occur prior to the death of motor neurons, and thus may be considered an early indicator for the diagnosis and prognosis of ALS. However, the exact molecular mechanisms underlying early‑onset WM damage in ALS have yet to be elucidated. The present review explored the detailed anatomy of WM and identified several pathological mechanisms that may be implicated in WM damage in ALS. In addition, it associated the pathophysiological alterations of WM, which may contribute to motor neuron death in ALS, with similar mechanisms of WM damage that are involved in multiple sclerosis (MS). Furthermore, the early detection of WM damage in ALS, using neuroimaging techniques, may lead to earlier therapeutic intervention, using immunomodulatory treatment strategies similar to those used in relapsing‑remitting MS, aimed at delaying WM damage in ALS. Early therapeutic approaches may have the potential to delay motor neuron damage and thus prolong the survival of patients with ALS. The therapeutic interventions that are currently available for ALS are only marginally effective. However, early intervention with immunomodulatory drugs may slow the progression of WM damage in the early stages of ALS, thus delaying motor neuron death and increasing the life expectancy of patients with ALS.
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Affiliation(s)
- Ting Zhou
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0T5, Canada
- Department of Human Anatomy and Cell Science, College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Tina Khorshid Ahmad
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0T5, Canada
| | - Kiana Gozda
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0T5, Canada
| | - Jessica Truong
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0T5, Canada
| | - Jiming Kong
- Department of Human Anatomy and Cell Science, College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
| | - Michael Namaka
- College of Pharmacy, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0T5, Canada
- Department of Human Anatomy and Cell Science, College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0J9, Canada
- College of Pharmacy, Third Military Medical University, Chongqing 400038, P.R. China
- Department of Medical Rehabilitation, College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 0T6, Canada
- Department of Internal Medicine, College of Medicine, Rady Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3E 1R9, Canada
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Khorshid Ahmad T, Zhou T, AlTaweel K, Cortes C, Lillico R, Lakowski TM, Gozda K, Namaka MP. Experimental Autoimmune Encephalomyelitis (EAE)-Induced Elevated Expression of the E1 Isoform of Methyl CpG Binding Protein 2 (MeCP2E1): Implications in Multiple Sclerosis (MS)-Induced Neurological Disability and Associated Myelin Damage. Int J Mol Sci 2017; 18:ijms18061254. [PMID: 28604632 PMCID: PMC5486076 DOI: 10.3390/ijms18061254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2017] [Revised: 04/15/2017] [Accepted: 05/13/2017] [Indexed: 12/26/2022] Open
Abstract
Multiple sclerosis (MS) is a chronic neurological disease characterized by the destruction of central nervous system (CNS) myelin. At present, there is no cure for MS due to the inability to repair damaged myelin. Although the neurotrophin brain derived neurotrophic factor (BDNF) has a beneficial role in myelin repair, these effects may be hampered by the over-expression of a transcriptional repressor isoform of methyl CpG binding protein 2 (MeCP2) called MeCP2E1. We hypothesize that following experimental autoimmune encephalomyelitis (EAE)-induced myelin damage, the immune system induction of the pathogenic MeCP2E1 isoform hampers the myelin repair process by repressing BDNF expression. Using an EAE model of MS, we identify the temporal gene and protein expression changes of MeCP2E1, MeCP2E2 and BDNF. The expression changes of these key biological targets were then correlated with the temporal changes in neurological disability scores (NDS) over the entire disease course. Our results indicate that MeCP2E1 mRNA levels are elevated in EAE animals relative to naïve control (NC) and active control (AC) animals during all time points of disease progression. Our results suggest that the EAE-induced elevations in MeCP2E1 expression contribute to the repressed BDNF production in the spinal cord (SC). The sub-optimal levels of BDNF result in sustained NDS and associated myelin damage throughout the entire disease course. Conversely, we observed no significant differences in the expression patterns displayed for the MeCP2E2 isoform amongst our experimental groups. However, our results demonstrate that baseline protein expression ratios between the MeCP2E1 versus MeCP2E2 isoforms in the SC are higher than those identified within the dorsal root ganglia (DRG). Thus, the DRG represents a more conducive environment than that of the SC for BDNF production and transport to the CNS to assist in myelin repair. Henceforth, the sub-optimal BDNF levels we report in the SC may arise from the elevated MeCP2E1 vs. MeCP2E2 ratio in the SC that creates a more hostile environment thereby preventing local BDNF production. At the level of transcript, we demonstrate that EAE-induces the pathological enhanced expression of MeCP2E1 that contributes to enhanced NDS during the entire disease course. Thus, the pathological induction of the MeCP2E1 isoform contributes to the disruption of the normal homeostatic signaling equilibrium network that exists between cytokines, neurotrophins and chemokines that regulate the myelin repair process by repressing BDNF. Our research suggests that the elevated ratio of MeCP2E1 relative to MeCP2E2 may be a useful diagnostic marker that clinicians can utilize to determine the degree of neurological disability with associated myelin damage. The elevated MeCP2E1 vs. MeCP2E2 ratios (E1/E2) in the SC prevent BDNF from reaching optimal levels required for myelin repair. Thus, the lower E1/E2 ratios in the DRG, allow the DRG to serve as a weak secondary compensatory mechanism for enhanced production and delivery of BDNF to the SC to try to assist in myelin repair.
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Affiliation(s)
- Tina Khorshid Ahmad
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Ting Zhou
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Khaled AlTaweel
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Claudia Cortes
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Ryan Lillico
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Ted Martin Lakowski
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Kiana Gozda
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
| | - Michael Peter Namaka
- College of Pharmacy, Faculty of Health Sciences, University of Manitoba, Manitoba, Winnipeg, MB R3E 0T5, Canada.
- College of Pharmacy, Third Military Medical University, Chongqing 400038, China.
- Department of Medical Rehabilitation, College of Medicine, Faculty of Health Sciences, Winnipeg, MB R3E 0T6, Canada.
- Department of Internal Medicine, College of Medicine, Faculty of Health Sciences, University of Manitoba, Winnipeg, MB R3A 1R9, Canada.
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Nicotinamide Administration Improves Remyelination after Stroke. Neural Plast 2017; 2017:7019803. [PMID: 28656112 PMCID: PMC5471593 DOI: 10.1155/2017/7019803] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2016] [Revised: 02/16/2017] [Accepted: 03/13/2017] [Indexed: 01/07/2023] Open
Abstract
AIMS Stroke is a leading cause of morbidity and mortality. This study aimed to determine whether nicotinamide administration could improve remyelination after stroke and reveal the underlying mechanism. METHODS Adult male C57BL/6J mice were intraperitoneally (i.p.) administered with nicotinamide (200 mg/kg, daily) or saline after stroke induced by photothrombotic occlusion of the middle cerebral artery. FK866 (3 mg/kg, daily, bis in die), an inhibitor of NAMPT, and ANA-12 (0.5 mg/kg, daily), an antagonist of tropomyosin-related kinase B (TrkB), were administered intraperitoneally 1 h before nicotinamide administration. Functional recovery, MRI, and histological assessment were performed after stroke at different time points. RESULTS The nicotinamide-treated mice showed significantly lower infarct area 7 d after stroke induction and significantly higher fractional anisotropy (FA) in the ipsilesional internal capsule (IC) 14 d after stroke induction than the other groups. Higher levels of NAD+, BDNF, and remyelination markers were observed in the nicotinamide-treated group. FK866 administration reduced NAD+ and BDNF levels in the nicotinamide-treated group. ANA-12 administration impaired the recovery from stroke with no effect on NAD+ and BDNF levels. Furthermore, lesser functional deficits were observed in the nicotinamide-treated group than in the control group. CONCLUSIONS Nicotinamide administration improves remyelination after stroke via the NAD+/BDNF/TrkB pathway.
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Cho JH, Jung JY, Lee BJ, Lee K, Park JW, Bu Y. Epimedii Herba: A Promising Herbal Medicine for Neuroplasticity. Phytother Res 2017; 31:838-848. [PMID: 28382688 DOI: 10.1002/ptr.5807] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2016] [Revised: 02/27/2017] [Accepted: 03/02/2017] [Indexed: 01/21/2023]
Abstract
Epimedii Herba (EH) is an herbal medicine originating from several plants of the genus Epimedium. It is a major therapeutic option for kidney yang deficiency syndrome, which is closely related to androgen hormones and also has been used to treat hemiplegia following a stroke in traditional medicine of Korea and PR China. To date, many clinical and basic researches of EH have shown the activities on functional recovery from brain diseases. Recently, neuroplasticity, which is the spontaneous reaction of the brain in response to diseases, has been shown to accelerate functional recovery. In addition, androgen hormones including testosterone are known to be the representative of neuroplasticity factors in the brain recovery processes. In this review, we described the neuro-pharmacological activities of EH, focusing on neuroplasticity. Thirty-three kinds of papers from MEDLINE/PubMed, EMBASE, and CNKI were identified and analyzed. We categorized the results into five types based on neuroplasticity mechanisms and presented the definition of each category and briefly described the results of these papers. Altogether, we can suggest that neuroplasticity is a novel viewpoint for guiding future brain research of EH and provide the evidence for the development of new clinical applications using EH in the treatment of brain diseases. Copyright © 2017 John Wiley & Sons, Ltd.
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Affiliation(s)
- Jae-Heung Cho
- College of Korean Medicine, Kyung Hee University, Seoul, Korea
| | - Jae-Young Jung
- College of Korean Medicine, Kyung Hee University, Seoul, Korea
| | - Beom-Joon Lee
- College of Korean Medicine, Kyung Hee University, Seoul, Korea
| | - Kyungjin Lee
- College of Korean Medicine, Kyung Hee University, Seoul, Korea
| | - Jae-Woo Park
- College of Korean Medicine, Kyung Hee University, Seoul, Korea
| | - Youngmin Bu
- College of Korean Medicine, Kyung Hee University, Seoul, Korea
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Signaling by FGF Receptor 2, Not FGF Receptor 1, Regulates Myelin Thickness through Activation of ERK1/2-MAPK, Which Promotes mTORC1 Activity in an Akt-Independent Manner. J Neurosci 2017; 37:2931-2946. [PMID: 28193689 DOI: 10.1523/jneurosci.3316-16.2017] [Citation(s) in RCA: 39] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2016] [Revised: 01/06/2017] [Accepted: 02/01/2017] [Indexed: 12/21/2022] Open
Abstract
FGF signaling has emerged as a significant "late-stage" regulator of myelin thickness in the CNS, independent of oligodendrocyte differentiation. Therefore, it is critically important to identify the specific FGF receptor type and its downstream signaling molecules in oligodendrocytes to obtain better insights into the regulatory mechanisms of myelin growth. Here, we show that FGF receptor type 2 (FGFR2) is highly enriched at the paranodal loops of myelin. Conditional ablation of this receptor-type, but not FGF receptor type 1 (FGFR1), resulted in attenuation of myelin growth, expression of major myelin genes, key transcription factor Myrf and extracellular signal-regulated protein kinase 1 and 2 (ERK1/2) activity. This was rescued by upregulating ERK1/2 activity in these mice, strongly suggesting that ERK1/2 are key transducers of FGFR2 signals for myelin growth. However, given that the PI3K/Akt/mechanistic target of rapamycin (mTOR) pathway is also known to regulate myelin thickness, we examined FGFR2-deficient mice for the expression of key signaling molecules in this pathway. A significant downregulation of p-mTOR, p-Raptor, and p-S6RP was observed, which was restored to normal by elevating ERK1/2 activity in these mice. Similar downregulation of these molecules was observed in ERK1/2 knock-out mice. Interestingly, since p-Akt levels remained largely unchanged in these mice, it suggests a mechanism of mTORC1 activation by ERK1/2 in an Akt-independent manner in oligodendrocytes. Taken together, these data support a model in which FGFs, possibly from axons, activate FGFR2 in the oligodendrocyte/myelin compartment to increase ERK1/2 activation, which ultimately targets Myrf, as well as converges with the PI3K/Akt/mTOR pathway at the level of mTORC1, working together to drive the growth of the myelin sheath, thus increasing myelin thickness.SIGNIFICANCE STATEMENT It is well accepted that myelin is a biologically active membrane in active communication with the axons. However, the axonal signals, the receptors on myelin, and the integration of intracellular signaling pathways emanating downstream from these receptors that drive the growth of the myelin sheath remain poorly understood in the CNS. This study brings up the intriguing possibility that FGF receptor 2, in the oligodendrocyte/myelin compartment, may be one such signal. Importantly, it provides compelling evidence linking FGFR2 with the ERK1/2-MAPK pathway, which converges with the PI3K/Akt/mTOR (mechanistic target of rapamycin) pathway at the level of mTORC1 and also regulates the transcription factor Myrf, together providing a mechanistic framework for regulating both the transcriptional and translational machinery required for the proper growth of the myelin sheath.
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Hu ZL, Li N, Wei X, Tang L, Wang TH, Chen XM. Neuroprotective effects of BDNF and GDNF in intravitreally transplanted mesenchymal stem cells after optic nerve crush in mice. Int J Ophthalmol 2017; 10:35-42. [PMID: 28149774 DOI: 10.18240/ijo.2017.01.06] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/21/2016] [Accepted: 09/04/2016] [Indexed: 02/05/2023] Open
Abstract
AIM To assess the neuro-protective effect of bone marrow mesenchymal stem cells (BMSCs) on retinal ganglion cells (RGCs) following optic nerve crush in mice. METHODS C56BL/6J mice were treated with intravitreal injection of PBS, BMSCs, BDNF-interference BMSCs (BIM), and GDNF-interference BMSCs (GIM) following optic nerve crush, respectively. The number of surviving RGCs was determined by whole-mount retinas and frozen sections, while certain mRNA or protein was detected by q-PCR or ELISA, respectively. RESULTS The density (cell number/mm2) of RGCs was 410.77±56.70 in the retina 21d after optic nerve crush without any treatment, compared to 1351.39±195.97 in the normal control (P<0.05). RGCs in BMSCs treated eyes was 625.07±89.64/mm2, significantly higher than that of no or PBS treatment (P<0.05). While RGCs was even less in the retina with intravitreal injection of BIM (354.07+39.77) and GIM (326.67+33.37) than that without treatment (P<0.05). BMSCs injection improved the internal BDNF expression in retinas. CONCLUSION Optic nerve crush caused rust loss of RGCs and intravitreally transplanted BMSCs at some extent protected RGCs from death. The effect of BMSCs and level of BDNF in retinas are both related to BDNF and GDNF expression in BMSCs.
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Affiliation(s)
- Zong-Li Hu
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Ni Li
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Xin Wei
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Li Tang
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Ting-Hua Wang
- Institute of Neurological Disease, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
| | - Xiao-Ming Chen
- Department of Ophthalmology, West China Hospital, Sichuan University, Chengdu 610041, Sichuan Province, China
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Mariga A, Mitre M, Chao MV. Consequences of brain-derived neurotrophic factor withdrawal in CNS neurons and implications in disease. Neurobiol Dis 2017; 97:73-79. [PMID: 27015693 PMCID: PMC5295364 DOI: 10.1016/j.nbd.2016.03.009] [Citation(s) in RCA: 52] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 02/20/2016] [Accepted: 03/09/2016] [Indexed: 01/07/2023] Open
Abstract
Growth factor withdrawal has been studied across different species and has been shown to have dramatic consequences on cell survival. In the nervous system, withdrawal of nerve growth factor (NGF) from sympathetic and sensory neurons results in substantial neuronal cell death, signifying a requirement for NGF for the survival of neurons in the peripheral nervous system (PNS). In contrast to the PNS, withdrawal of central nervous system (CNS) enriched brain-derived neurotrophic factor (BDNF) has little effect on cell survival but is indispensible for synaptic plasticity. Given that most early events in neuropsychiatric disorders are marked by a loss of synapses, lack of BDNF may thus be an important part of a cascade of events that leads to neuronal degeneration. Here we review reports on the effects of BDNF withdrawal on CNS neurons and discuss the relevance of the loss in disease.
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Affiliation(s)
- Abigail Mariga
- Department of Cell Biology, New York University School of Medicine, New York, NY, 10016, United States; Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, United States
| | - Mariela Mitre
- Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, United States; Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, United States
| | - Moses V Chao
- Department of Cell Biology, New York University School of Medicine, New York, NY, 10016, United States; Department of Neuroscience and Physiology, New York University School of Medicine, New York, NY, 10016, United States; Department of Psychiatry, New York University School of Medicine, New York, NY, 10016, United States; Skirball Institute for Biomolecular Medicine, New York University School of Medicine, New York, NY, 10016, United States
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Mysona BA, Zhao J, Bollinger KE. Role of BDNF/TrkB pathway in the visual system: Therapeutic implications for glaucoma. EXPERT REVIEW OF OPHTHALMOLOGY 2016; 12:69-81. [PMID: 28751923 DOI: 10.1080/17469899.2017.1259566] [Citation(s) in RCA: 29] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
INTRODUCTION Neuroprotective therapeutics are needed to treat glaucoma, an optic neuropathy that results in death of retinal ganglion cells (RGCs). AREAS COVERED The BDNF/TrkB pathway is important for RGC survival. Temporal and spatial alterations in the BDNF/TrkB pathway occur in development and in response to acute optic nerve injury and to glaucoma. In animal models, BDNF supplementation is successful at slowing RGC death after acute optic nerve injury and in glaucoma, however, the BDNF/TrkB signaling is not the only pathway supporting long term RGC survival. EXPERT COMMENTARY Much remains to be discovered about the interaction between retrograde, anterograde, and retinal BDNF/TrkB signaling pathways in both neurons and glia. An ideal therapeutic agent for glaucoma likely has several modes of action that target multiple mechanisms of neurodegeneration including the BDNF/TrkB pathway.
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Affiliation(s)
- B A Mysona
- Augusta University Department of Cellular Biology and Anatomy, James and Jean Culver Vision Discovery Institute. Address: Augusta University Department of Cellular Biology and Anatomy, Health Sciences Campus, 1120 15th Street, Augusta, GA 30912, USA,
| | - J Zhao
- Medical College of Georgia, Department of Ophthalmology at Augusta University, James and Jean Culver Vision Discovery Institute. Address: Medical College of Georgia, Department of Ophthalmology at Augusta University, 1120 15th Street, Augusta, GA 30912, USA,
| | - K E Bollinger
- Medical College of Georgia, Department of Ophthalmology at Augusta University, Augusta University Department of Cellular Biology and Anatomy, James and Jean Culver Vision Discovery Institute. Address: Medical College of Georgia, Department of Ophthalmology at Augusta University, 1120 15th Street, Augusta, GA 30912, USA,
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Serum Markers of Neurodegeneration in Maple Syrup Urine Disease. Mol Neurobiol 2016; 54:5709-5719. [PMID: 27660262 DOI: 10.1007/s12035-016-0116-8] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/04/2016] [Accepted: 09/09/2016] [Indexed: 12/14/2022]
Abstract
Maple syrup urine disease (MSUD) is an inherited disorder caused by deficient activity of the branched-chain α-keto acid dehydrogenase complex involved in the degradation pathway of branched-chain amino acids (BCAAs) and their respective α-keto-acids. Patients affected by MSUD present severe neurological symptoms and brain abnormalities, whose pathophysiology is poorly known. However, preclinical studies have suggested alterations in markers involved with neurodegeneration. Because there are no studies in the literature that report the neurodegenerative markers in MSUD patients, the present study evaluated neurodegenerative markers (brain-derived neurotrophic factor (BDNF), cathepsin D, neural cell adhesion molecule (NCAM), plasminogen activator inhibitor-1 total (PAI-1 (total)), platelet-derived growth factor AA (PDGF-AA), PDGF-AB/BB) in plasma from 10 MSUD patients during dietary treatment. Our results showed a significant decrease in BDNF and PDGF-AA levels in MSUD patients. On the other hand, NCAM and cathepsin D levels were significantly greater in MSUD patients compared to the control group, while no significant changes were observed in the levels of PAI-1 (total) and PDGF-AB/BB between the control and MSUD groups. Our data show that MSUD patients present alterations in proteins involved in the neurodegenerative process. Thus, the present findings corroborate previous studies that demonstrated that neurotrophic factors and lysosomal proteases may contribute, along with other mechanisms, to the intellectual deficit and neurodegeneration observed in MSUD.
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Hughes EG, Appel B. The cell biology of CNS myelination. Curr Opin Neurobiol 2016; 39:93-100. [PMID: 27152449 PMCID: PMC4987163 DOI: 10.1016/j.conb.2016.04.013] [Citation(s) in RCA: 53] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/06/2016] [Revised: 04/19/2016] [Accepted: 04/20/2016] [Indexed: 11/21/2022]
Abstract
Myelination of axons in the central nervous system results from the remarkable ability of oligodendrocytes to wrap multiple axons with highly specialized membrane. Because myelin membrane grows as it ensheaths axons, cytoskeletal rearrangements that enable ensheathment must be coordinated with myelin production. Because the myelin sheaths of a single oligodendrocyte can differ in thickness and length, mechanisms that coordinate axon ensheathment with myelin growth likely operate within individual oligodendrocyte processes. Recent studies have revealed new information about how assembly and disassembly of actin filaments helps drive the leading edge of nascent myelin membrane around and along axons. Concurrently, other investigations have begun to uncover evidence of communication between axons and oligodendrocytes that can regulate myelin formation.
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Affiliation(s)
- Ethan G Hughes
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, United States
| | - Bruce Appel
- Department of Cell and Developmental Biology, University of Colorado School of Medicine, Aurora, CO 80045, United States; Department of Pediatrics, University of Colorado School of Medicine, Aurora, CO 80045, United States.
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Enhanced brain-derived neurotrophic factor delivery by ultrasound and microbubbles promotes white matter repair after stroke. Biomaterials 2016; 100:41-52. [PMID: 27240161 DOI: 10.1016/j.biomaterials.2016.05.028] [Citation(s) in RCA: 30] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/11/2015] [Revised: 05/04/2016] [Accepted: 05/17/2016] [Indexed: 11/20/2022]
Abstract
Ultrasound-targeted microbubble destruction (UTMD) has been shown to be a promising tool to deliver proteins to select body areas. This study aimed to analyze whether UTMD was able to deliver brain-derived neurotrophic factor (BDNF) to the brain, enhancing functional recovery and white matter repair, in an animal model of subcortical stroke induced by endothelin (ET)-1. UTMD was used to deliver BDNF to the brain 24 h after stroke. This technique was shown to be safe, given there were no cases of hemorrhagic transformation or blood brain barrier (BBB) leakage. UTMD treatment was associated with increased brain BDNF levels at 4 h after administration. Targeted ultrasound delivery of BDNF improved functional recovery associated with fiber tract connectivity restoration, increasing oligodendrocyte markers and remyelination compared to BDNF alone administration in an experimental animal model of white matter injury.
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Wisniewski MSW, Carvalho-Silva M, Gomes LM, Zapelini HG, Schuck PF, Ferreira GC, Scaini G, Streck EL. Intracerebroventricular administration of α-ketoisocaproic acid decreases brain-derived neurotrophic factor and nerve growth factor levels in brain of young rats. Metab Brain Dis 2016; 31:377-83. [PMID: 26586008 DOI: 10.1007/s11011-015-9768-8] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/28/2015] [Accepted: 11/13/2015] [Indexed: 12/12/2022]
Abstract
Maple syrup urine disease (MSUD) is an inherited aminoacidopathy resulting from dysfunction of the branched-chain keto acid dehydrogenase complex, leading to accumulation of the branched-chain amino acids (BCAA) leucine, isoleucine and valine as well as their corresponding transaminated branched-chain α-ketoacids. This disorder is clinically characterized by ketoacidosis, seizures, coma, psychomotor delay and mental retardation whose pathophysiology is not completely understood. Recent studies have shown that oxidative stress may be involved in neuropathology of MSUD. However, the effect of accumulating α-ketoacids in MSUD on neurotrophic factors has not been investigated. Thus, the objective of the present study was to evaluate the effects of acute intracerebroventricular administration of α-ketoisocaproic acid (KIC) on brain-derived neurotrophic factor (BDNF) and nerve growth factor (NGF) levels in the brains of young male rats. Ours results showed that intracerebroventricular administration of KIC decreased BDNF levels in hippocampus, striatum and cerebral cortex, without induce a detectable change in pro-BDNF levels. Moreover, NGF levels in the hippocampus were reduced after intracerebroventricular administration of KIC. In conclusion, these data suggest that the effects of KIC on demyelination and memory processes may be mediated by reduced trophic support of BDNF and NGF. Moreover, lower levels of BDNF and NGF are consistent with the hypothesis that a deficit in this neurotrophic factor may contribute to the structural and functional alterations of brain underlying the psychopathology of MSUD, supporting the hypothesis of a neurodegenerative process in MSUD.
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Affiliation(s)
- Miriam S W Wisniewski
- Laboratório de Bioenergética e Núcleo de Excelência em Neurociências Aplicadas de Santa Catarina (NENASC), Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Av. Universitária, 1105, Criciúma, SC, 88806-000, Brazil
- Instituto Nacional de Ciência e Tecnologia Translacional em Medicina (INCT-TM), Porto Alegre, RS, Brazil
| | - Milena Carvalho-Silva
- Laboratório de Bioenergética e Núcleo de Excelência em Neurociências Aplicadas de Santa Catarina (NENASC), Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Av. Universitária, 1105, Criciúma, SC, 88806-000, Brazil
- Instituto Nacional de Ciência e Tecnologia Translacional em Medicina (INCT-TM), Porto Alegre, RS, Brazil
| | - Lara M Gomes
- Laboratório de Bioenergética e Núcleo de Excelência em Neurociências Aplicadas de Santa Catarina (NENASC), Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Av. Universitária, 1105, Criciúma, SC, 88806-000, Brazil
- Instituto Nacional de Ciência e Tecnologia Translacional em Medicina (INCT-TM), Porto Alegre, RS, Brazil
| | - Hugo G Zapelini
- Laboratório de Erros Inatos do Metabolismo, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - Patrícia F Schuck
- Laboratório de Erros Inatos do Metabolismo, Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Criciúma, SC, Brazil
| | - Gustavo C Ferreira
- Laboratório de Neuroquímica, Instituto de Bioquímica Médica, Universidade Federal do Rio de Janeiro, Rio de Janeiro, Brazil
| | - Giselli Scaini
- Laboratório de Bioenergética e Núcleo de Excelência em Neurociências Aplicadas de Santa Catarina (NENASC), Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Av. Universitária, 1105, Criciúma, SC, 88806-000, Brazil
- Instituto Nacional de Ciência e Tecnologia Translacional em Medicina (INCT-TM), Porto Alegre, RS, Brazil
| | - Emilio L Streck
- Laboratório de Bioenergética e Núcleo de Excelência em Neurociências Aplicadas de Santa Catarina (NENASC), Programa de Pós-Graduação em Ciências da Saúde, Universidade do Extremo Sul Catarinense, Av. Universitária, 1105, Criciúma, SC, 88806-000, Brazil.
- Instituto Nacional de Ciência e Tecnologia Translacional em Medicina (INCT-TM), Porto Alegre, RS, Brazil.
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Wang Y, Jones-Tabah J, Chakravarty P, Stewart A, Muotri A, Laposa RR, Svejstrup JQ. Pharmacological Bypass of Cockayne Syndrome B Function in Neuronal Differentiation. Cell Rep 2016; 14:2554-61. [PMID: 26972010 PMCID: PMC4806223 DOI: 10.1016/j.celrep.2016.02.051] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/09/2015] [Revised: 12/22/2015] [Accepted: 02/08/2016] [Indexed: 12/20/2022] Open
Abstract
Cockayne syndrome (CS) is a severe neurodevelopmental disorder characterized by growth abnormalities, premature aging, and photosensitivity. Mutation of Cockayne syndrome B (CSB) affects neuronal gene expression and differentiation, so we attempted to bypass its function by expressing downstream target genes. Intriguingly, ectopic expression of Synaptotagmin 9 (SYT9), a key component of the machinery controlling neurotrophin release, bypasses the need for CSB in neuritogenesis. Importantly, brain-derived neurotrophic factor (BDNF), a neurotrophin implicated in neuronal differentiation and synaptic modulation, and pharmacological mimics such as 7,8-dihydroxyflavone and amitriptyline can compensate for CSB deficiency in cell models of neuronal differentiation as well. SYT9 and BDNF are downregulated in CS patient brain tissue, further indicating that sub-optimal neurotrophin signaling underlies neurological defects in CS. In addition to shedding light on cellular mechanisms underlying CS and pointing to future avenues for pharmacological intervention, these data suggest an important role for SYT9 in neuronal differentiation.
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Affiliation(s)
- Yuming Wang
- Mechanisms of Transcription Laboratory, Clare Hall Laboratories, The Francis Crick Institute, South Mimms, Hertfordshire EN6 3LD, UK
| | - Jace Jones-Tabah
- Department of Pharmacology and Toxicology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Probir Chakravarty
- Bioinformatics & Biostatistics Group, The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Aengus Stewart
- Bioinformatics & Biostatistics Group, The Francis Crick Institute, 44 Lincoln's Inn Fields, London WC2A 3LY, UK
| | - Alysson Muotri
- Department of Pediatrics, University of California, San Diego, 2800 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA; Department of Cellular and Molecular Medicine, University of California, San Diego, 2800 Torrey Pines Scenic Drive, La Jolla, CA 92037, USA
| | - Rebecca R Laposa
- Department of Pharmacology and Toxicology, University of Toronto, 1 King's College Circle, Toronto, ON M5S 1A8, Canada
| | - Jesper Q Svejstrup
- Mechanisms of Transcription Laboratory, Clare Hall Laboratories, The Francis Crick Institute, South Mimms, Hertfordshire EN6 3LD, UK.
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Astrocytes Promote Oligodendrogenesis after White Matter Damage via Brain-Derived Neurotrophic Factor. J Neurosci 2016; 35:14002-8. [PMID: 26468200 DOI: 10.1523/jneurosci.1592-15.2015] [Citation(s) in RCA: 170] [Impact Index Per Article: 21.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022] Open
Abstract
UNLABELLED Oligodendrocyte precursor cells (OPCs) in the adult brain contribute to white matter homeostasis. After white matter damage, OPCs compensate for oligodendrocyte loss by differentiating into mature oligodendrocytes. However, the underlying mechanisms remain to be fully defined. Here, we test the hypothesis that, during endogenous recovery from white matter ischemic injury, astrocytes support the maturation of OPCs by secreting brain-derived neurotrophic factor (BDNF). For in vitro experiments, cultured primary OPCs and astrocytes were prepared from postnatal day 2 rat cortex. When OPCs were subjected to chemical hypoxic stress by exposing them to sublethal CoCl2 for 7 d, in vitro OPC differentiation into oligodendrocytes was significantly suppressed. Conditioned medium from astrocytes (astro-medium) restored the process of OPC maturation even under the stressed conditions. When astro-medium was filtered with TrkB-Fc to remove BDNF, the BDNF-deficient astro-medium no longer supported OPC maturation. For in vivo experiments, we analyzed a transgenic mouse line (GFAP(cre)/BDNF(wt/fl)) in which BDNF expression is downregulated specifically in GFAP(+) astrocytes. Both wild-type (GFAP(wt)/BDNF(wt/fl) mice) and transgenic mice were subjected to prolonged cerebral hypoperfusion by bilateral common carotid artery stenosis. As expected, compared with wild-type mice, the transgenic mice exhibited a lower number of newly generated oligodendrocytes and larger white matter damage. Together, these findings demonstrate that, during endogenous recovery from white matter damage, astrocytes may promote oligodendrogenesis by secreting BDNF. SIGNIFICANCE STATEMENT The repair of white matter after brain injury and neurodegeneration remains a tremendous hurdle for a wide spectrum of CNS disorders. One potentially important opportunity may reside in the response of residual oligodendrocyte precursor cells (OPCs). OPCs may serve as a back-up for generating mature oligodendrocytes in damaged white matter. However, the underlying mechanisms are still mostly unknown. Here, we use a combination of cell biology and an animal model to report a new pathway in which astrocyte-derived BDNF supports oligodendrogenesis and regeneration after white matter damage. These findings provide new mechanistic insight into white matter physiology and pathophysiology, which would be broadly and clinically applicable to CNS disease.
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After Intracerebral Hemorrhage, Oligodendrocyte Precursors Proliferate and Differentiate Inside White-Matter Tracts in the Rat Striatum. Transl Stroke Res 2016; 7:192-208. [PMID: 26743212 PMCID: PMC4873533 DOI: 10.1007/s12975-015-0445-3] [Citation(s) in RCA: 56] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/23/2015] [Revised: 12/17/2015] [Accepted: 12/28/2015] [Indexed: 02/06/2023]
Abstract
Damage to myelinated axons contributes to neurological deficits after acute CNS injury, including ischemic and hemorrhagic stroke. Potential treatments to promote re-myelination will require fully differentiated oligodendrocytes, but almost nothing is known about their fate following intracerebral hemorrhage (ICH). Using a rat model of ICH in the striatum, we quantified survival, proliferation, and differentiation of oligodendrocyte precursor cells (OPCs) (at 1, 3, 7, 14, and 28 days) in the peri-hematoma region, surrounding striatum, and contralateral striatum. In the peri-hematoma, the density of Olig2+ cells increased dramatically over the first 7 days, and this coincided with disorganization and fragmentation of myelinated axon bundles. Very little proliferation (Ki67+) of Olig2+ cells was seen in the anterior subventricular zone from 1 to 28 days. However, by 3 days, many were proliferating in the peri-hematoma region, suggesting that local proliferation expands their population. By 14 days, the density of Olig2+ cells declined in the peri-hematoma region, and, by 28 days, it reached the low level seen in the contralateral striatum. At these later times, many surviving axons were aligned into white-matter bundles, which appeared less swollen or fragmented. Oligodendrocyte cell maturation was prevalent over the 28-day period. Densities of immature OPCs (NG2+Olig2+) and mature (CC-1+Olig2+) oligodendrocytes in the peri-hematoma increased dramatically over the first week. Regardless of the maturation state, they increased preferentially inside the white-matter bundles. These results provide evidence that endogenous oligodendrocyte precursors proliferate and differentiate in the peri-hematoma region and have the potential to re-myelinate axon tracts after hemorrhagic stroke.
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Itoh K, Maki T, Lok J, Arai K. Mechanisms of cell-cell interaction in oligodendrogenesis and remyelination after stroke. Brain Res 2015; 1623:135-49. [PMID: 25960351 PMCID: PMC4569526 DOI: 10.1016/j.brainres.2015.04.039] [Citation(s) in RCA: 46] [Impact Index Per Article: 5.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2015] [Revised: 04/19/2015] [Accepted: 04/20/2015] [Indexed: 12/20/2022]
Abstract
White matter damage is a clinically important aspect of several central nervous system diseases, including stroke. Cerebral white matter primarily consists of axonal bundles ensheathed with myelin secreted by mature oligodendrocytes, which play an important role in neurotransmission between different areas of gray matter. During the acute phase of stroke, damage to oligodendrocytes leads to white matter dysfunction through the loss of myelin. On the contrary, during the chronic phase, white matter components promote an environment, which is favorable for neural repair, vascular remodeling, and remyelination. For effective remyelination to take place, oligodendrocyte precursor cells (OPCs) play critical roles by proliferating and differentiating into mature oligodendrocytes, which help to decrease the burden of axonal injury. Notably, other types of cells contribute to these OPC responses under the ischemic conditions. This mini-review summarizes the non-cell autonomous mechanisms in oligodendrogenesis and remyelination after white matter damage, focusing on how OPCs receive support from their neighboring cells. This article is part of a Special Issue entitled SI: Cell Interactions In Stroke.
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Affiliation(s)
- Kanako Itoh
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Takakuni Maki
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Josephine Lok
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA; Department of Pediatrics, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Ken Arai
- Neuroprotection Research Laboratory, Departments of Radiology and Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.
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Peckham H, Giuffrida L, Wood R, Gonsalvez D, Ferner A, Kilpatrick TJ, Murray SS, Xiao J. Fyn is an intermediate kinase that BDNF utilizes to promote oligodendrocyte myelination. Glia 2015; 64:255-69. [PMID: 26449489 DOI: 10.1002/glia.22927] [Citation(s) in RCA: 36] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2015] [Revised: 08/17/2015] [Accepted: 09/15/2015] [Indexed: 01/17/2023]
Abstract
Fyn, a member of the Src family of nonreceptor tyrosine kinases, promotes central nervous system myelination during development; however the mechanisms mediating this effect remain unknown. Here we show that Fyn phosphorylation is modulated by BDNF in vivo. Concordant with this, we find that BDNF stimulates Fyn phosphorylation in myelinating cocultures, an effect dependent on oligodendroglial expression of TrkB. Importantly, PP2, a pharmacological inhibitor of Src family kinases, not only abrogated the promyelinating influence of BDNF in vitro, but also attenuated BDNF-induced phosphorylation of Erk1/2 in oligodendrocytes. Over-expression of Fyn in oligodendrocytes significantly promotes phosphorylation of Erk1/2, and promotes myelination to the extent that exogenous BDNF exerts no additive effect in vitro. In contrast, expression of a kinase-dead mutant of Fyn in oligodendrocytes significantly inhibited BDNF-induced activation of Erk1/2 and abrogated the promyelinating effect of BDNF. Analysis of white matter tracts in vivo revealed that phosphorylated Fyn primarily colocalized with mature oligodendrocytes, and was rarely observed in oligodendrocyte progenitor cells, a profile that closely parallels the detection of phosphorylated Erk1/2 in the developing central nervous system. Taken together, these data identify that Fyn kinase exerts a key role in mediating the promyelinating influence of BDNF. Here we identify a pathway in which BDNF activation of oligodendroglial TrkB receptors stimulates the phosphorylation of Fyn, a necessary step required to potentiate the phosphorylation of Erk1/2, which in turn regulates oligodendrocyte myelination.
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Affiliation(s)
- Haley Peckham
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Lauren Giuffrida
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Rhiannon Wood
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - David Gonsalvez
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Anita Ferner
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Trevor J Kilpatrick
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Simon S Murray
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, 3010, Australia
| | - Junhua Xiao
- Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, Victoria, 3010, Australia
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47
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Neurodevelopmental sequelae associated with gray and white matter changes and their cellular basis: A comparison between Autism Spectrum Disorder, ADHD and dyslexia. Int J Dev Neurosci 2015; 46:132-43. [PMID: 26456538 DOI: 10.1016/j.ijdevneu.2015.02.007] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2015] [Revised: 02/11/2015] [Accepted: 02/17/2015] [Indexed: 11/22/2022] Open
Abstract
Many psychiatric diseases, such as major depression and schizophrenia, are accompanied by patterns of gray matter and white matter changes in the cortex that may be due to structural pathologies of synapses and their dendrites in the gray matter on the one hand and to pathologies in myelinating oligodendrocytes on the other. Here the possibility has been briefly examined that such a generalization might also hold for Autistic Spectrum Disorders (ASD). Evidence is presented that gray matter changes that accompany ASD may in fact reflect changes in synapses and subsequently of their dendrites, whereas those in the white matter reflect changes in myelination due to pathologies of oligodendrocytes. It is proposed that such structural pathologies during development provide a coherent biological model not only for the onset and course of ASD but also provide the basis for development and systematic evaluation of new treatment strategies.
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48
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Mohajeri M, Sadeghizadeh M, Najafi F, Javan M. Polymerized nano-curcumin attenuates neurological symptoms in EAE model of multiple sclerosis through down regulation of inflammatory and oxidative processes and enhancing neuroprotection and myelin repair. Neuropharmacology 2015. [PMID: 26211978 DOI: 10.1016/j.neuropharm.2015.07.013] [Citation(s) in RCA: 107] [Impact Index Per Article: 11.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Multiple Sclerosis (MS) is an inflammatory demyelinating disorder of central nervous system (CNS). Polyphenol curcumin has been used in traditional medicine as an effective drug for a variety of diseases. Different formulations of curcumin are introduced to increase its stability and effectiveness. Here we have examined the effect of polymerized form of nano-curcumin (PNC) on experimental autoimmune encephalomyelitis (EAE) as an animal model of MS. EAE was induced in female Lewis rats and PNC or curcumin was daily administrated intraperitonealy from day 12-29 post immunization. When the prophylactic effect of PNC was under investigation, rats received PNC from the first day of immunization. Treatment with PNC resulted in decreased scores of disease in therapeutic and prophylactic administration when compared with control group. Staining by luxol fast blue and H&E and immuno-staining of lumbar spinal cord cross sections, confirmed a significant decrease in the amounts of demyelination, inflammation and BBB breaking down. Gene expression studies in lumbar spinal cord showed a corrected balance of pro-inflammatory and anti-inflammatory genes expression, decreased oxidative stress, improved remyelination and increased progenitor cell markers after treatment with PNC. Our results demonstrated an efficient therapeutic effect of PNC as an anti-inflammatory and anti-oxidative stress agent, with significant effects on the EAE scores and myelin repair mechanisms.
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Affiliation(s)
- Maryam Mohajeri
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran
| | - Majid Sadeghizadeh
- Department of Molecular Genetics, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
| | - Farhood Najafi
- Department of Resin and Additives, Institute for Color Science and Technology, Tehran, 16765-654, Iran
| | - Mohammad Javan
- Department of Physiology, Faculty of Medical Sciences, Tarbiat Modares University, Tehran, Iran.
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The Acquisition of Target Dependence by Developing Rat Retinal Ganglion Cells. eNeuro 2015; 2:eN-NWR-0044-14. [PMID: 26464991 PMCID: PMC4586937 DOI: 10.1523/eneuro.0044-14.2015] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/21/2014] [Revised: 06/22/2015] [Accepted: 06/23/2015] [Indexed: 11/23/2022] Open
Abstract
Similar to neurons in the peripheral nervous system, immature CNS-derived RGCs become dependent on target-derived neurotrophic support as their axons reach termination sites in the brain. To study the factors that influence this developmental transition we took advantage of the fact that rat RGCs are born, and target innervation occurs, over a protracted period of time. Early-born RGCs have axons in the SC by birth (P0), whereas axons from late-born RGCs do not innervate the SC until P4-P5. Birth dating RGCs using EdU allowed us to identify RGCs (1) with axons still growing toward targets, (2) transitioning to target dependence, and (3) entirely dependent on target-derived support. Using laser-capture microdissection we isolated ∼34,000 EdU+ RGCs and analyzed transcript expression by custom qPCR array. Statistical analyses revealed a difference in gene expression profiles in actively growing RGCs compared with target-dependent RGCs, as well as in transitional versus target-dependent RGCs. Prior to innervation RGCs expressed high levels of BDNF and CNTFR α but lower levels of neurexin 1 mRNA. Analysis also revealed greater expression of transcripts for signaling molecules such as MAPK, Akt, CREB, and STAT. In a supporting in vitro study, purified birth-dated P1 RGCs were cultured for 24-48 h with or without BDNF; lack of BDNF resulted in significant loss of early-born but not late-born RGCs. In summary, we identified several important changes in RGC signaling that may form the basis for the switch from target independence to dependence.
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Social Experience-Dependent Myelination: An Implication for Psychiatric Disorders. Neural Plast 2015; 2015:465345. [PMID: 26078885 PMCID: PMC4452491 DOI: 10.1155/2015/465345] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/24/2015] [Revised: 05/05/2015] [Accepted: 05/06/2015] [Indexed: 12/02/2022] Open
Abstract
Myelination is one of the strategies to promote the conduction velocity of axons in order to adjust to evolving environment in vertebrates. It has been shown that myelin formation depends on genetic programing and experience, including multiple factors, intracellular and extracellular molecules, and neuronal activities. Recently, accumulating studies have shown that myelination in the central nervous system changes more dynamically in response to neuronal activities and experience than expected. Among experiences, social experience-dependent myelination draws attention as one of the critical pathobiologies of psychiatric disorders. In this review, we summarize the mechanisms of neuronal activity-dependent and social experience-dependent myelination and discuss the contribution of social experience-dependent myelination to the pathology of psychiatric disorders.
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