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Bai CB, Sun S, Roholt A, Benson E, Edberg D, Medicetty S, Dutta R, Kidd G, Macklin WB, Trapp B. A mouse model for testing remyelinating therapies. Exp Neurol 2016; 283:330-40. [PMID: 27384502 DOI: 10.1016/j.expneurol.2016.06.033] [Citation(s) in RCA: 35] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2016] [Revised: 06/29/2016] [Accepted: 06/30/2016] [Indexed: 01/14/2023]
Abstract
Used in combination with immunomodulatory therapies, remyelinating therapies are a viable therapeutic approach for treating individuals with multiple sclerosis. Studies of postmortem MS brains identified greater remyelination in demyelinated cerebral cortex than in demyelinated brain white matter and implicated reactive astrocytes as an inhibitor of white matter remyelination. An animal model that recapitulates these phenotypes would benefit the development of remyelination therapeutics. We have used a modified cuprizone protocol that causes a consistent and robust demyelination of mouse white matter and cerebral cortex. Spontaneous remyelination occurred significantly faster in the cerebral cortex than in white matter and reactive astrocytes were more abundant in white matter lesions. Remyelination of white matter and cerebral cortex was therapeutically enhanced by daily injections of thyroid hormone triiodothyronine (T3). In summary, we describe an in vivo demyelination/remyelination paradigm that can be powered to determine efficacy of therapies that enhance white matter and cortical remyelination.
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Affiliation(s)
- C Brian Bai
- Renovo Neural, Inc., 10000 Cedar Ave., Cleveland, OH 44106, United States.
| | - Sunny Sun
- Renovo Neural, Inc., 10000 Cedar Ave., Cleveland, OH 44106, United States
| | - Andrew Roholt
- Renovo Neural, Inc., 10000 Cedar Ave., Cleveland, OH 44106, United States
| | - Emily Benson
- Renovo Neural, Inc., 10000 Cedar Ave., Cleveland, OH 44106, United States
| | - Dale Edberg
- Renovo Neural, Inc., 10000 Cedar Ave., Cleveland, OH 44106, United States
| | - Satish Medicetty
- Renovo Neural, Inc., 10000 Cedar Ave., Cleveland, OH 44106, United States
| | - Ranjan Dutta
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Grahame Kidd
- Renovo Neural, Inc., 10000 Cedar Ave., Cleveland, OH 44106, United States; Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Wendy B Macklin
- Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States
| | - Bruce Trapp
- Renovo Neural, Inc., 10000 Cedar Ave., Cleveland, OH 44106, United States; Department of Neurosciences, Lerner Research Institute, Cleveland Clinic, Cleveland, OH 44195, United States
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Nordströma U, Beauvais G, Ghosh A, Pulikkaparambil Sasidharan BC, Lundblad M, Fuchs J, Joshi RL, Lipton JW, Roholt A, Medicetty S, Feinstein TN, Steiner JA, Escobar Galvis ML, Prochiantz A, Brundin P. Progressive nigrostriatal terminal dysfunction and degeneration in the engrailed1 heterozygous mouse model of Parkinson's disease. Neurobiol Dis 2014; 73:70-82. [PMID: 25281317 DOI: 10.1016/j.nbd.2014.09.012] [Citation(s) in RCA: 64] [Impact Index Per Article: 6.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/11/2014] [Revised: 08/28/2014] [Accepted: 09/21/2014] [Indexed: 01/17/2023] Open
Abstract
Current research on Parkinson's disease (PD) pathogenesis requires relevant animal models that mimic the gradual and progressive development of neuronal dysfunction and degeneration that characterizes the disease. Polymorphisms in engrailed 1 (En1), a homeobox transcription factor that is crucial for both the development and survival of mesencephalic dopaminergic neurons, are associated with sporadic PD. This suggests that En1 mutant mice might be a promising candidate PD model. Indeed, a mouse that lacks one En1 allele exhibits decreased mitochondrial complex I activity and progressive midbrain dopamine neuron degeneration in adulthood, both features associated with PD. We aimed to further characterize the disease-like phenotype of these En1(+/-) mice with a focus on early neurodegenerative changes that can be utilized to score efficacy of future disease modifying studies. We observed early terminal defects in the dopaminergic nigrostriatal pathway in En1(+/-) mice. Several weeks before a significant loss of dopaminergic neurons in the substantia nigra could be detected, we found that striatal terminals expressing high levels of dopaminergic neuron markers TH, VMAT2, and DAT were dystrophic and swollen. Using transmission electron microscopy, we identified electron dense bodies consistent with abnormal autophagic vacuoles in these terminal swellings. In line with these findings, we detected an up-regulation of the mTOR pathway, concurrent with a downregulation of the autophagic marker LC3B, in ventral midbrain and nigral dopaminergic neurons of the En1(+/-) mice. This supports the notion that autophagic protein degradation is reduced in the absence of one En1 allele. We imaged the nigrostriatal pathway using the CLARITY technique and observed many fragmented axons in the medial forebrain bundle of the En1(+/-) mice, consistent with axonal maintenance failure. Using in vivo electrochemistry, we found that nigrostriatal terminals in the dorsal striatum were severely deficient in dopamine release and reuptake. Our findings support a progressive retrograde degeneration of En1(+/-) nigrostriatal neurons, akin to what is suggested to occur in PD. We suggest that using the En1(+/-) mice as a model will provide further key insights into PD pathogenesis, and propose that axon terminal integrity and function can be utilized to estimate dopaminergic neuron health and efficacy of experimental PD therapies.
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Affiliation(s)
- Ulrika Nordströma
- Neuronal Survival Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, BMC B11, 221 84 Lund, Sweden
| | - Geneviève Beauvais
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Anamitra Ghosh
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Baby Chakrapani Pulikkaparambil Sasidharan
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Martin Lundblad
- Developmental and Regenerative Neurobiology, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, BMC A11, 221 84, Lund University, Sweden
| | - Julia Fuchs
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, Paris, France
| | - Rajiv L Joshi
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, Paris, France
| | - Jack W Lipton
- Department of Translational Science and Molecular Medicine and The Udall Center of Excellence in Parkinson's Disease Research, Michigan State University, Grand Rapids, MI, USA
| | - Andrew Roholt
- Renovo Neural, Inc. 10000 Cedar Avenue, Cleveland, OH 44106, USA
| | - Satish Medicetty
- Renovo Neural, Inc. 10000 Cedar Avenue, Cleveland, OH 44106, USA
| | - Timothy N Feinstein
- Confocal Microscopy and Quantitative Imaging Core Facility,Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Jennifer A Steiner
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Martha L Escobar Galvis
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
| | - Alain Prochiantz
- Collège de France, Center for Interdisciplinary Research in Biology (CIRB)/Centre National de la Recherche Scientifique, Unité Mixte de Recherche 7241/Institut National de la Santé et de la Recherche Médicale U1050, Labex Memolife, Paris, France
| | - Patrik Brundin
- Neuronal Survival Unit, Wallenberg Neuroscience Center, Department of Experimental Medical Science, Lund University, BMC B11, 221 84 Lund, Sweden
- Laboratory for Translational Parkinson's Disease Research, Center for Neurodegenerative Science, Van Andel Research Institute, 333 Bostwick Ave, N.E., Grand Rapids, MI 49503, USA
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Bohórquez DV, Samsa LA, Roholt A, Medicetty S, Chandra R, Liddle RA. An enteroendocrine cell-enteric glia connection revealed by 3D electron microscopy. PLoS One 2014; 9:e89881. [PMID: 24587096 PMCID: PMC3935946 DOI: 10.1371/journal.pone.0089881] [Citation(s) in RCA: 157] [Impact Index Per Article: 15.7] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2013] [Accepted: 01/28/2014] [Indexed: 11/25/2022] Open
Abstract
The enteroendocrine cell is the cornerstone of gastrointestinal chemosensation. In the intestine and colon, this cell is stimulated by nutrients, tastants that elicit the perception of flavor, and bacterial by-products; and in response, the cell secretes hormones like cholecystokinin and peptide YY – both potent regulators of appetite. The development of transgenic mice with enteroendocrine cells expressing green fluorescent protein has allowed for the elucidation of the apical nutrient sensing mechanisms of the cell. However, the basal secretory aspects of the enteroendocrine cell remain largely unexplored, particularly because a complete account of the enteroendocrine cell ultrastructure does not exist. Today, the fine ultrastructure of a specific cell can be revealed in the third dimension thanks to the invention of serial block face scanning electron microscopy (SBEM). Here, we bridged confocal microscopy with SBEM to identify the enteroendocrine cell of the mouse and study its ultrastructure in the third dimension. The results demonstrated that 73.5% of the peptide-secreting vesicles in the enteroendocrine cell are contained within an axon-like basal process. We called this process a neuropod. This neuropod contains neurofilaments, which are typical structural proteins of axons. Surprisingly, the SBEM data also demonstrated that the enteroendocrine cell neuropod is escorted by enteric glia – the cells that nurture enteric neurons. We extended these structural findings into an in vitro intestinal organoid system, in which the addition of glial derived neurotrophic factors enhanced the development of neuropods in enteroendocrine cells. These findings open a new avenue of exploration in gastrointestinal chemosensation by unveiling an unforeseen physical relationship between enteric glia and enteroendocrine cells.
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Affiliation(s)
- Diego V. Bohórquez
- Departments of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
- * E-mail:
| | - Leigh A. Samsa
- Department of Cell Biology and Physiology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, United States of America
| | - Andrew Roholt
- Renovo Neural Incorporation, Cleveland, Ohio, United States of America
| | - Satish Medicetty
- Renovo Neural Incorporation, Cleveland, Ohio, United States of America
| | - Rashmi Chandra
- Departments of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
| | - Rodger A. Liddle
- Departments of Medicine, Duke University Medical Center, Durham, North Carolina, United States of America
- Veterans Affairs Medical Center, Durham, North Carolina, United States of America
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