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Dai S, Feng Y, Lu C, Zhang H, Ma W, Xie W, Wu X, Luo P, Zhang L, Fei F, Fei Z, Li X. Impairment of Autophagic Flux After Hypobaric Hypoxia Potentiates Oxidative Stress and Cognitive Function Disturbances in Mice. Neurosci Bull 2024; 40:35-49. [PMID: 37608137 PMCID: PMC10774493 DOI: 10.1007/s12264-023-01099-6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/20/2022] [Accepted: 06/01/2023] [Indexed: 08/24/2023] Open
Abstract
Acute hypobaric hypoxic brain damage is a potentially fatal high-altitude sickness. Autophagy plays a critical role in ischemic brain injury, but its role in hypobaric hypoxia (HH) remains unknown. Here we used an HH chamber to demonstrate that acute HH exposure impairs autophagic activity in both the early and late stages of the mouse brain, and is partially responsible for HH-induced oxidative stress, neuronal loss, and brain damage. The autophagic agonist rapamycin only promotes the initiation of autophagy. By proteome analysis, a screen showed that protein dynamin2 (DNM2) potentially regulates autophagic flux. Overexpression of DNM2 significantly increased the formation of autolysosomes, thus maintaining autophagic flux in combination with rapamycin. Furthermore, the enhancement of autophagic activity attenuated oxidative stress and neurological deficits after HH exposure. These results contribute to evidence supporting the conclusion that DNM2-mediated autophagic flux represents a new therapeutic target in HH-induced brain damage.
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Affiliation(s)
- Shuhui Dai
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
- National Translational Science Center for Molecular Medicine and Department of Cell Biology, Fourth Military Medical University, Xi'an, 710000, China
| | - Yuan Feng
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Chuanhao Lu
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Hongchen Zhang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Wenke Ma
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
- Department of Neurosurgery, The Central Hospital of Baoji, Baoji, 721000, China
| | - Wenyu Xie
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Xiuquan Wu
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Peng Luo
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Lei Zhang
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Fei Fei
- Department of Ophthalmology, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China
| | - Zhou Fei
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China.
| | - Xia Li
- Department of Neurosurgery, Xijing Hospital, Fourth Military Medical University, Xi'an, 710000, China.
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Cook AA, Jayabal S, Sheng J, Fields E, Leung TCS, Quilez S, McNicholas E, Lau L, Huang S, Watt AJ. Activation of TrkB-Akt signaling rescues deficits in a mouse model of SCA6. SCIENCE ADVANCES 2022; 8:eabh3260. [PMID: 36112675 PMCID: PMC9481119 DOI: 10.1126/sciadv.abh3260] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2021] [Accepted: 07/29/2022] [Indexed: 06/01/2023]
Abstract
Spinocerebellar ataxia type 6 (SCA6) is a neurodegenerative disease resulting in motor coordination deficits and cerebellar pathology. Expression of brain-derived neurotrophic factor (BDNF) is reduced in postmortem tissue from SCA6 patients. Here, we show that levels of cerebellar BDNF and its receptor, tropomyosin receptor kinase B (TrkB), are reduced at an early disease stage in a mouse model of SCA6 (SCA684Q/84Q). One month of exercise elevated cerebellar BDNF expression and improved ataxia and cerebellar Purkinje cell firing rate deficits. A TrkB agonist, 7,8-dihydroxyflavone (7,8-DHF), likewise improved motor coordination and Purkinje cell firing rate and elevated downstream Akt signaling. Prolonged 7,8-DHF administration persistently improved ataxia when treatment commenced near disease onset but was ineffective when treatment was started late. These data suggest that 7,8-DHF, which is orally bioavailable and crosses the blood-brain barrier, is a promising therapeutic for SCA6 and argue for the importance of early intervention for SCA6.
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Affiliation(s)
- Anna A. Cook
- Biology Department, McGill University, Montreal, QC, Canada
| | - Sriram Jayabal
- Biology Department, McGill University, Montreal, QC, Canada
- Integrated Neuroscience Program, McGill University, Montreal, QC, Canada
- Department of Neurobiology, Stanford School of Medicine, Stanford, CA, USA
| | - Jacky Sheng
- Biology Department, McGill University, Montreal, QC, Canada
| | - Eviatar Fields
- Biology Department, McGill University, Montreal, QC, Canada
- Integrated Neuroscience Program, McGill University, Montreal, QC, Canada
| | | | - Sabrina Quilez
- Biology Department, McGill University, Montreal, QC, Canada
| | | | - Lois Lau
- Biology Department, McGill University, Montreal, QC, Canada
| | - Shixia Huang
- Department of Molecular and Cellular Biology, Department of Education, Innovation and Technology, Dan L. Duncan Cancer Center, Baylor College of Medicine, Houston, TX, USA
| | - Alanna J. Watt
- Biology Department, McGill University, Montreal, QC, Canada
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3
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Jennen L, Mazereel V, Lecei A, Samaey C, Vancampfort D, van Winkel R. Exercise to spot the differences: a framework for the effect of exercise on hippocampal pattern separation in humans. Rev Neurosci 2022; 33:555-582. [PMID: 35172422 DOI: 10.1515/revneuro-2021-0156] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2021] [Accepted: 01/16/2022] [Indexed: 12/12/2022]
Abstract
Exercise has a beneficial effect on mental health and cognitive functioning, but the exact underlying mechanisms remain largely unknown. In this review, we focus on the effect of exercise on hippocampal pattern separation, which is a key component of episodic memory. Research has associated exercise with improvements in pattern separation. We propose an integrated framework mechanistically explaining this relationship. The framework is divided into three pathways, describing the pro-neuroplastic, anti-inflammatory and hormonal effects of exercise. The pathways are heavily intertwined and may result in functional and structural changes in the hippocampus. These changes can ultimately affect pattern separation through direct and indirect connections. The proposed framework might guide future research on the effect of exercise on pattern separation in the hippocampus.
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Affiliation(s)
- Lise Jennen
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium
| | - Victor Mazereel
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium.,University Psychiatric Center KU Leuven, Leuvensesteenweg 517, 3070 Leuven-Kortenberg, Belgium
| | - Aleksandra Lecei
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium
| | - Celine Samaey
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium
| | - Davy Vancampfort
- University Psychiatric Center KU Leuven, Leuvensesteenweg 517, 3070 Leuven-Kortenberg, Belgium.,KU Leuven Department of Rehabilitation Sciences, ON IV Herestraat 49, bus 1510, 3000, Leuven, Belgium
| | - Ruud van Winkel
- KU Leuven, Department of Neurosciences, Center for Clinical Psychiatry, ON V Herestraat 49, bus 1029, 3000 Leuven, Belgium.,University Psychiatric Center KU Leuven, Leuvensesteenweg 517, 3070 Leuven-Kortenberg, Belgium
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4
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Exercise mimetics: harnessing the therapeutic effects of physical activity. Nat Rev Drug Discov 2021; 20:862-879. [PMID: 34103713 DOI: 10.1038/s41573-021-00217-1] [Citation(s) in RCA: 40] [Impact Index Per Article: 13.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/22/2021] [Indexed: 02/05/2023]
Abstract
Exercise mimetics are a proposed class of therapeutics that specifically mimic or enhance the therapeutic effects of exercise. Increased physical activity has demonstrated positive effects in preventing and ameliorating a wide range of diseases, including brain disorders such as Alzheimer disease and dementia, cancer, diabetes and cardiovascular disease. This article discusses the molecular mechanisms and signalling pathways associated with the beneficial effects of physical activity, focusing on effects on brain function and cognitive enhancement. Emerging therapeutic targets and strategies for the development of exercise mimetics, particularly in the field of central nervous system disorders, as well as the associated opportunities and challenges, are discussed.
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Wilson C, Rogers J, Chen F, Li S, Adlard PA, Hannan AJ, Renoir T. Exercise ameliorates aberrant synaptic plasticity without enhancing adult-born cell survival in the hippocampus of serotonin transporter knockout mice. Brain Struct Funct 2021; 226:1991-1999. [PMID: 34052925 DOI: 10.1007/s00429-021-02283-y] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2020] [Accepted: 04/21/2021] [Indexed: 12/28/2022]
Abstract
Deficits in hippocampal cellular and synaptic plasticity are frequently associated with cognitive and mood disorders, and indeed common mechanisms of antidepressants are thought to involve neuroplastic processes. Here, we investigate hippocampal adult-born cell survival and synaptic plasticity (long-term potentiation, LTP, and long-term depression, LTD) in serotonin transporter (5-HTT) knockout (KO) mice. From 8 weeks of age, mice either continued in standard-housing conditions or were given access to voluntary running wheels for 1 month. Electrophysiology was performed on hippocampal slices to measure LTP and LTD, and immunohistochemistry was used to assess cell proliferation and subsequent survival in the dentate gyrus. The results revealed a reduced LTP in 5-HTT KO mice that was restored to wild-type (WT) levels after chronic exercise. While LTD appeared normal in 5-HTT KO, exercise decreased the magnitude of LTD in both WT and 5-HTT KO mice. Furthermore, although 5-HTT KO mice had normal hippocampal adult-born cell survival, they did not benefit from the pro-proliferative effects of exercise observed in WT animals. Taken together, these findings suggest that reduced 5-HTT expression is associated with significant alterations to functional neuroplasticity. Interestingly, 5-HTT appeared necessary for exercise-induced augmentation of adult-born hippocampal cell survival, yet exercise corrected the LTP impairment displayed by 5-HTT KO mice. Together, our findings further highlight the salience of serotonergic signalling in mediating the neurophysiological benefits of exercise.
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Affiliation(s)
- Carey Wilson
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia
| | - Jake Rogers
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia
| | - Feng Chen
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia
| | - Shanshan Li
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia
| | - Paul A Adlard
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia.,Melbourne Dementia Research Centre, Florey Institute of Neuroscience and Mental Health, University of Melbourne, Parkville, Melbourne, Australia
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia.,Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Melbourne, Australia
| | - Thibault Renoir
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Melbourne, VIC, 3010, Australia. .,Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Melbourne, Australia.
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Wilson C, Li S, Hannan AJ, Renoir T. Antidepressant-like effects of ketamine in a mouse model of serotonergic dysfunction. Neuropharmacology 2020; 168:107998. [PMID: 32061666 DOI: 10.1016/j.neuropharm.2020.107998] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 02/05/2020] [Accepted: 02/09/2020] [Indexed: 12/28/2022]
Abstract
Traditional monoaminergic treatments of depression frequently exhibit suboptimal tolerability and effectiveness. The 'short' (s) allele variant of 5-HTTLPR is known to compromise transcriptional efficacy of the serotonin transporter (5-HTT) and can reduce treatment response to traditional antidepressants (e.g. selective serotonin reuptake inhibitors or SSRIs). This study sought to establish the 5-HTT knock-out (KO) line as a mouse model of SSRI-resistant depression and assess its response to a novel glutamatergic antidepressant, ketamine, a non-competitive N-methyl-d-aspartate receptor (NMDAR) antagonist. Following acute antidepressant treatment, 5-HTT KO mice and wild-type (WT) controls were subjected to the forced-swim test (FST), one of the most widely used techniques to detect acute antidepressant response. As hypothesised, when assessed 30 min after administration in the FST, the SSRI sertraline (20 mg/kg, i.p.) produced antidepressant-like effects in WT control but not in 5-HTT KO mice. In contrast, ketamine (20 mg/kg, i.p.) induced antidepressant-like effects in both genotypes. 5-HTT KO mice also exhibited a reduced locomotor response to both MK-801 (another NMDAR antagonist) and ketamine, and reduced GluN2A protein levels in the hippocampus, suggesting glutamatergic dysfunction in this model. These results highlight the utility of 5-HTT KO mice as a relevant model of SSRI-resistant depression and demonstrate that ketamine can produce acute antidepressant-like effects in conditions of 5-HTT deficiency. These findings extend existing literature that indicates ketamine is effective in ameliorating symptoms of treatment-resistant depression and may have implications for understanding the cellular and molecular mechanisms underlying the antidepressant effects of ketamine. This article is part of the special issue entitled 'Serotonin Research: Crossing Scales and Boundaries'.
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Affiliation(s)
- Carey Wilson
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Australia; Melbourne School of Psychological Science, University of Melbourne, Parkville, Australia
| | - Shanshan Li
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Australia
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Australia; Department of Anatomy and Neuroscience, University of Melbourne, Parkville, Australia
| | - Thibault Renoir
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Parkville, Australia; Facssulty of Medicine, Dentistry and Health Sciences, University of Melbourne, Parkville, Australia.
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Rogers J, Chen F, Stanic D, Farzana F, Li S, Zeleznikow-Johnston AM, Nithianantharajah J, Churilov L, Adlard PA, Lanfumey L, Hannan AJ, Renoir T. Paradoxical effects of exercise on hippocampal plasticity and cognition in mice with a heterozygous null mutation in the serotonin transporter gene. Br J Pharmacol 2019; 176:3279-3296. [PMID: 31167040 DOI: 10.1111/bph.14760] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2018] [Revised: 05/08/2019] [Accepted: 05/14/2019] [Indexed: 12/30/2022] Open
Abstract
BACKGROUND AND PURPOSE Exercise is known to improve cognitive function, but the exact synaptic and cellular mechanisms remain unclear. We investigated the potential role of the serotonin (5-HT) transporter (SERT) in mediating these effects. EXPERIMENTAL APPROACH Hippocampal long-term potentiation (LTP) and neurogenesis were measured in standard-housed and exercising (wheel running) wild-type (WT) and SERT heterozygous (HET) mice. We also assessed hippocampal-dependent cognition using the Morris water maze (MWM) and a spatial pattern separation touchscreen task. KEY RESULTS SERT HET mice had impaired hippocampal LTP regardless of the housing conditions. Exercise increased hippocampal neurogenesis in WT mice. However, this was not observed in SERT HET animals, even though both genotypes used the running wheels to a similar extent. We also found that standard-housed SERT HET mice displayed altered cognitive flexibility than WT littermate controls in the MWM reversal learning task. However, SERT HET mice no longer exhibited this phenotype after exercise. Cognitive changes, specific to SERT HET mice in the exercise condition, were also revealed on the touchscreen spatial pattern separation task, especially when the cognitive pattern separation load was at its highest. CONCLUSIONS AND IMPLICATIONS Our study is the first evidence of reduced hippocampal LTP in SERT HET mice. We also show that functional SERT is required for exercise-induced increase in adult neurogenesis. Paradoxically, exercise had a negative impact on hippocampal-dependent cognitive tasks, especially in SERT HET mice. Taken together, our results suggest unique complex interactions between exercise and altered 5-HT homeostasis.
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Affiliation(s)
- Jake Rogers
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia
| | - Feng Chen
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia
| | - Davor Stanic
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia
| | - Farheen Farzana
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia
| | - Shanshan Li
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia
| | - Ariel M Zeleznikow-Johnston
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia
| | - Jess Nithianantharajah
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia
| | - Leonid Churilov
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia.,School of Mathematical and Geospatial Sciences, RMIT University, Melbourne, VIC, Australia
| | - Paul A Adlard
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia
| | - Laurence Lanfumey
- UMR S894, Université Paris Descartes, Paris, France.,Centre de Psychiatrie et Neurosciences, Inserm UMR 894, Paris, France
| | - Anthony J Hannan
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia.,Department of Anatomy and Neuroscience, University of Melbourne, Melbourne, VIC, Australia.,Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, VIC, Australia
| | - Thibault Renoir
- Florey Institute of Neuroscience and Mental Health, Melbourne Brain Centre, University of Melbourne, Melbourne, VIC, Australia.,Faculty of Medicine, Dentistry and Health Sciences, University of Melbourne, Melbourne, VIC, Australia
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