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Kuwamura M, Tanimura S, Hasegawa Y, Hoshiai R, Moriyama Y, Tanaka M, Takenaka S, Nagayoshi H, Izawa T, Yamate J, Kuramoto T, Serikawa T. Downregulation of aspartoacylase during the progression of myelin breakdown in the dmy mutant rat with mitochondrial magnesium channel MRS2 defect. Brain Res 2019; 1718:169-75. [PMID: 31100216 DOI: 10.1016/j.brainres.2019.05.017] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [What about the content of this article? (0)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2018] [Revised: 05/11/2019] [Accepted: 05/13/2019] [Indexed: 11/22/2022]
Abstract
OBJECTIVE The dmy rat is an autosomal recessive mutant that exhibits severe rapid myelin breakdown throughout the central nervous system at 7-8 weeks of age. The dmy rat has a point mutation in Mrs2 gene, which encodes an essential component of the major electrophoretic Mg2+ influx system in the mitochondria. However, it remains unknown how mitochondrial dysfunction leads to the myelin breakdown. METHODS We focused on the aspartoacylase (ASPA) and mitochondrion-related metabolites to clarify the mechanism of myelin pathology in dmy rats. Aspa mRNA was significantly decreased in both the gray matter and the ventral white matter of spinal cord in the dmy rats from 4 to 8 weeks of age. Very faint immunohistochemical expression for ASPA was noted in the gray and white matter of the affected dmy rats at 8 weeks. Liquid chromatography mass spectrometry revealed no different amount of N-acetylaspartate (NAA), which is synthesized from aspartate and acetyl-coenzyme A (CoA) in neurons, in the brain and spinal cord between the dmy and control rats. CONCLUSION Our results indicated that the pyruvate dehydrogenase activity might be reduced due to the loss of Mg2+ transport activity in the mitochondria of the dmy rats, suggesting acetyl CoA production might be reduced. The number of oligodendrocytes was well preserved until 7 weeks. It is intriguing that prior to the myelin destruction at 7-8 weeks, disrupted expression of Aspa mRNA and ASPA protein undergoes from early stage of myelinogenesis. These data indicate that ASPA expression would be a useful index to evaluate a function of oligodendrocyte in the dmy rat.
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Homberg JR, Olivier JDA, VandenBroeke M, Youn J, Ellenbroek AK, Karel P, Shan L, van Boxtel R, Ooms S, Balemans M, Langedijk J, Muller M, Vriend G, Cools AR, Cuppen E, Ellenbroek BA. The role of the dopamine D1 receptor in social cognition: studies using a novel genetic rat model. Dis Model Mech 2016; 9:1147-1158. [PMID: 27483345 PMCID: PMC5087833 DOI: 10.1242/dmm.024752] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/01/2016] [Accepted: 05/04/2016] [Indexed: 01/25/2023] Open
Abstract
Social cognition is an endophenotype that is impaired in schizophrenia and several other (comorbid) psychiatric disorders. One of the modulators of social cognition is dopamine, but its role is not clear. The effects of dopamine are mediated through dopamine receptors, including the dopamine D1 receptor (Drd1). Because current Drd1 receptor agonists are not Drd1 selective, pharmacological tools are not sufficient to delineate the role of the Drd1. Here, we describe a novel rat model with a genetic mutation in Drd1 in which we measured basic behavioural phenotypes and social cognition. The I116S mutation was predicted to render the receptor less stable. In line with this computational prediction, this Drd1 mutation led to a decreased transmembrane insertion of Drd1, whereas Drd1 expression, as measured by Drd1 mRNA levels, remained unaffected. Owing to decreased transmembrane Drd1 insertion, the mutant rats displayed normal basic motoric and neurological parameters, as well as locomotor activity and anxiety-like behaviour. However, measures of social cognition like social interaction, scent marking, pup ultrasonic vocalizations and sociability, were strongly reduced in the mutant rats. This profile of the Drd1 mutant rat offers the field of neuroscience a novel genetic rat model to study a series of psychiatric disorders including schizophrenia, autism, depression, bipolar disorder and drug addiction.
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Affiliation(s)
- Judith R Homberg
- Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen 6525 EZ, The Netherlands
| | - Jocelien D A Olivier
- Department of Neurobiology, Unit Behavioural Neuroscience, Groningen Institute for Evolutionary Life Sciences, University of Groningen, Groningen 9700 CC, The Netherlands
| | - Marie VandenBroeke
- Victoria University of Wellington, School of Psychology, PO Box 600, Wellington 6040, New Zealand
| | - Jiun Youn
- Victoria University of Wellington, School of Psychology, PO Box 600, Wellington 6040, New Zealand
| | - Arabella K Ellenbroek
- Victoria University of Wellington, School of Psychology, PO Box 600, Wellington 6040, New Zealand
| | - Peter Karel
- Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen 6525 EZ, The Netherlands
| | - Ling Shan
- Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen 6525 EZ, The Netherlands
| | - Ruben van Boxtel
- Hubrecht Institute, KNAW and University Medical Centre Utrecht, Utrecht 3584 CT, The Netherlands
| | - Sharon Ooms
- Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen 6525 EZ, The Netherlands
| | - Monique Balemans
- Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen 6525 EZ, The Netherlands
| | - Jacqueline Langedijk
- Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen 6525 EZ, The Netherlands
| | - Mareike Muller
- Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen 6525 EZ, The Netherlands
| | - Gert Vriend
- CMBI, Radboud University Nijmegen Medical Centre, Geert Grooteplein 26-28, Nijmegen 6525 GA, The Netherlands
| | - Alexander R Cools
- Donders Institute for Brain, Cognition and Behaviour, Department of Cognitive Neuroscience, Radboud University Medical Centre, Nijmegen 6525 EZ, The Netherlands
| | - Edwin Cuppen
- Hubrecht Institute, KNAW and University Medical Centre Utrecht, Utrecht 3584 CT, The Netherlands
| | - Bart A Ellenbroek
- Victoria University of Wellington, School of Psychology, PO Box 600, Wellington 6040, New Zealand
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