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Cui C, Jiang X, Wang Y, Li C, Lin Z, Wei Y, Ni Q. Cerebral Hypoxia-Induced Molecular Alterations and Their Impact on the Physiology of Neurons and Dendritic Spines: A Comprehensive Review. Cell Mol Neurobiol 2024; 44:58. [PMID: 39105862 PMCID: PMC11303443 DOI: 10.1007/s10571-024-01491-4] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2024] [Accepted: 07/15/2024] [Indexed: 08/07/2024]
Abstract
This article comprehensively reviews how cerebral hypoxia impacts the physiological state of neurons and dendritic spines through a series of molecular changes, and explores the causal relationship between these changes and neuronal functional impairment. As a severe pathological condition, cerebral hypoxia can significantly alter the morphology and function of neurons and dendritic spines. Specifically, dendritic spines, being the critical structures for neurons to receive information, undergo changes such as a reduction in number and morphological abnormalities under hypoxic conditions. These alterations further affect synaptic function, leading to neurotransmission disorders. This article delves into the roles of molecular pathways like MAPK, AMPA receptors, NMDA receptors, and BDNF in the hypoxia-induced changes in neurons and dendritic spines, and outlines current treatment strategies. Neurons are particularly sensitive to cerebral hypoxia, with their apical dendrites being vulnerable to damage, thereby affecting cognitive function. Additionally, astrocytes and microglia play an indispensable role in protecting neuronal and synaptic structures, regulating their normal functions, and contributing to the repair process following injury. These studies not only contribute to understanding the pathogenesis of related neurological diseases but also provide important insights for developing novel therapeutic strategies. Future research should further focus on the dynamic changes in neurons and dendritic spines under hypoxic conditions and their intrinsic connections with cognitive function.
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Affiliation(s)
- Chao Cui
- Hydrogen Medical Research Center, The Affiliated Taian City Central Hospital of Qingdao University, Taian, 271000, Shandong, China
| | - Xue Jiang
- Hydrogen Medical Research Center, The Affiliated Taian City Central Hospital of Qingdao University, Taian, 271000, Shandong, China
| | - Yumei Wang
- Hydrogen Medical Research Center, The Affiliated Taian City Central Hospital of Qingdao University, Taian, 271000, Shandong, China
| | - Chao Li
- Hydrogen Medical Research Center, The Affiliated Taian City Central Hospital of Qingdao University, Taian, 271000, Shandong, China
| | - Zhaochen Lin
- Hydrogen Medical Research Center, The Affiliated Taian City Central Hospital of Qingdao University, Taian, 271000, Shandong, China
| | - Youzhen Wei
- Hydrogen Medical Research Center, The Affiliated Taian City Central Hospital of Qingdao University, Taian, 271000, Shandong, China.
- Research Center for Translational Medicine & Key Laboratory of Arrhythmias of the Ministry of Education of China, Shanghai East Hospital, Tongji University School of Medicine, Shanghai, 200000, China.
| | - Qingbin Ni
- Hydrogen Medical Research Center, The Affiliated Taian City Central Hospital of Qingdao University, Taian, 271000, Shandong, China.
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Huff AD, Karlen-Amarante M, Oliveira LM, Ramirez JM. Chronic intermittent hypoxia reveals role of the Postinspiratory Complex in the mediation of normal swallow production. eLife 2024; 12:RP92175. [PMID: 38655918 PMCID: PMC11042803 DOI: 10.7554/elife.92175] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/26/2024] Open
Abstract
Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder that results in multiple bouts of intermittent hypoxia. OSA has many neurological and systemic comorbidities, including dysphagia, or disordered swallow, and discoordination with breathing. However, the mechanism in which chronic intermittent hypoxia (CIH) causes dysphagia is unknown. Recently, we showed the postinspiratory complex (PiCo) acts as an interface between the swallow pattern generator (SPG) and the inspiratory rhythm generator, the preBötzinger complex, to regulate proper swallow-breathing coordination (Huff et al., 2023). PiCo is characterized by interneurons co-expressing transporters for glutamate (Vglut2) and acetylcholine (ChAT). Here we show that optogenetic stimulation of ChATcre:Ai32, Vglut2cre:Ai32, and ChATcre:Vglut2FlpO:ChR2 mice exposed to CIH does not alter swallow-breathing coordination, but unexpectedly disrupts swallow behavior via triggering variable swallow motor patterns. This suggests that glutamatergic-cholinergic neurons in PiCo are not only critical for the regulation of swallow-breathing coordination, but also play an important role in the modulation of swallow motor patterning. Our study also suggests that swallow disruption, as seen in OSA, involves central nervous mechanisms interfering with swallow motor patterning and laryngeal activation. These findings are crucial for understanding the mechanisms underlying dysphagia, both in OSA and other breathing and neurological disorders.
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Affiliation(s)
- Alyssa D Huff
- Center for Integrative Brain Research, Seattle Children’s Research InstituteSeattleUnited States
| | - Marlusa Karlen-Amarante
- Center for Integrative Brain Research, Seattle Children’s Research InstituteSeattleUnited States
| | - Luiz M Oliveira
- Center for Integrative Brain Research, Seattle Children’s Research InstituteSeattleUnited States
| | - Jan-Marino Ramirez
- Center for Integrative Brain Research, Seattle Children’s Research InstituteSeattleUnited States
- Department of Neurological Surgery, University of Washington School of MedicineSeattleUnited States
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3
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Huff A, Karlen-Amarante M, Oliveira LM, Ramirez JM. Chronic Intermittent Hypoxia reveals role of the Postinspiratory Complex in the mediation of normal swallow production. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.09.26.559560. [PMID: 37808787 PMCID: PMC10557756 DOI: 10.1101/2023.09.26.559560] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 10/10/2023]
Abstract
Obstructive sleep apnea (OSA) is a prevalent sleep-related breathing disorder that results in multiple bouts of intermittent hypoxia. OSA has many neurologic and systemic comorbidities including dysphagia, or disordered swallow, and discoordination with breathing. However, the mechanism in which chronic intermittent hypoxia (CIH) causes dysphagia is unknown. Recently we showed the Postinspiratory complex (PiCo) acts as an interface between the swallow pattern generator (SPG) and the inspiratory rhythm generator, the preBötzinger Complex, to regulate proper swallow-breathing coordination (Huff et al., 2023). PiCo is characterized by interneurons co-expressing transporters for glutamate (Vglut2) and acetylcholine (ChAT). Here we show that optogenetic stimulation of ChATcre:Ai32, Vglut2cre:Ai32, and ChATcre:Vglut2FlpO:ChR2 mice exposed to CIH does not alter swallow-breathing coordination, but unexpectedly disrupts swallow behavior via triggering variable swallow motor patterns. This suggests, glutamatergic-cholinergic neurons in PiCo are not only critical for the regulation of swallow-breathing coordination, but also play an important role in the modulation of swallow motor patterning. Our study also suggests that swallow disruption, as seen in OSA, involves central nervous mechanisms interfering with swallow motor patterning and laryngeal activation. These findings are crucial for understanding the mechanisms underlying dysphagia, both in OSA and other breathing and neurological disorders.
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Affiliation(s)
- Alyssa Huff
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101
| | - Marlusa Karlen-Amarante
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101
| | - Luiz Marcelo Oliveira
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101
| | - Jan Marino Ramirez
- Center for Integrative Brain Research, Seattle Children’s Research Institute, Seattle, WA, 98101
- Department of Neurological Surgery, University of Washington School of Medicine, Seattle, WA, USA, 98108
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4
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Arias-Cavieres A, Garcia AJ. A consequence of immature breathing induces persistent changes in hippocampal synaptic plasticity and behavior: a role of prooxidant state and NMDA receptor imbalance. Front Mol Neurosci 2023; 16:1192833. [PMID: 37456523 PMCID: PMC10338931 DOI: 10.3389/fnmol.2023.1192833] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2023] [Accepted: 05/24/2023] [Indexed: 07/18/2023] Open
Abstract
Underdeveloped breathing results from premature birth and causes intermittent hypoxia during the early neonatal period. Neonatal intermittent hypoxia (nIH) is a condition linked to the increased risk of neurocognitive deficit later in life. However, the mechanistic basis of nIH-induced changes to neurophysiology remains poorly resolved. We investigated the impact of nIH on hippocampal synaptic plasticity and NMDA receptor (NMDAr) expression in neonatal mice. Our findings indicate that nIH induces a prooxidant state that leads to an imbalance in NMDAr subunit composition favoring GluN2B over GluN2A expression and impairs synaptic plasticity. These consequences persist in adulthood and coincide with deficits in spatial memory. Treatment with an antioxidant, manganese (III) tetrakis (1-methyl-4-pyridyl)porphyrin (MnTMPyP), during nIH effectively mitigated both immediate and long-term effects of nIH. However, MnTMPyP treatment post-nIH did not prevent long-lasting changes in either synaptic plasticity or behavior. In addition to demonstrating that the prooxidant state has a central role in nIH-mediated neurophysiological and behavioral deficits, our results also indicate that targeting the prooxidant state during a discrete therapeutic window may provide a potential avenue for mitigating long-term neurophysiological and behavioral outcomes that result from unstable breathing during early postnatal life.
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Affiliation(s)
- Alejandra Arias-Cavieres
- Institute for Integrative Physiology, The University of Chicago, Chicago, IL, United States
- Department of Medicine, Section of Emergency Medicine, The University of Chicago, Chicago, IL, United States
| | - Alfredo J. Garcia
- Institute for Integrative Physiology, The University of Chicago, Chicago, IL, United States
- Department of Medicine, Section of Emergency Medicine, The University of Chicago, Chicago, IL, United States
- University of Chicago Neuroscience Institute, University of Chicago, Chicago, IL, United States
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Carvalho-Rosa JD, Rodrigues NC, Silva-Cruz A, Vaz SH, Cunha-Reis D. Epileptiform activity influences theta-burst induced LTP in the adult hippocampus: a role for synaptic lipid raft disruption in early metaplasticity? Front Cell Neurosci 2023; 17:1117697. [PMID: 37228704 PMCID: PMC10203237 DOI: 10.3389/fncel.2023.1117697] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 04/13/2023] [Indexed: 05/27/2023] Open
Abstract
Non-epileptic seizures are identified as a common epileptogenic trigger. Early metaplasticity following seizures may contribute to epileptogenesis by abnormally altering synaptic strength and homeostatic plasticity. We now studied how in vitro epileptiform activity (EA) triggers early changes in CA1 long-term potentiation (LTP) induced by theta-burst stimulation (TBS) in rat hippocampal slices and the involvement of lipid rafts in these early metaplasticity events. Two forms of EA were induced: (1) interictal-like EA evoked by Mg2+ withdrawal and K+ elevation to 6 mM in the superfusion medium or (2) ictal-like EA induced by bicuculline (10 μM). Both EA patterns induced and LTP-like effect on CA1 synaptic transmission prior to LTP induction. LTP induced 30 min post EA was impaired, an effect more pronounced after ictal-like EA. LTP recovered to control levels 60 min post interictal-like EA but was still impaired 60 min after ictal-like EA. The synaptic molecular events underlying this altered LTP were investigated 30 min post EA in synaptosomes isolated from these slices. EA enhanced AMPA GluA1 Ser831 phosphorylation but decreased Ser845 phosphorylation and the GluA1/GluA2 ratio. Flotillin-1 and caveolin-1 were markedly decreased concomitantly with a marked increase in gephyrin levels and a less prominent increase in PSD-95. Altogether, EA differentially influences hippocampal CA1 LTP thorough regulation of GluA1/GluA2 levels and AMPA GluA1 phosphorylation suggesting that altered LTP post-seizures is a relevant target for antiepileptogenic therapies. In addition, this metaplasticity is also associated with marked alterations in classic and synaptic lipid raft markers, suggesting these may also constitute promising targets in epileptogenesis prevention.
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Affiliation(s)
- José D. Carvalho-Rosa
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
- BioISI–Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Nádia C. Rodrigues
- Departamento de Química e Bioquímica, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
| | - Armando Silva-Cruz
- BioISI–Biosystems and Integrative Sciences Institute, Faculdade de Ciências, Universidade de Lisboa, Lisbon, Portugal
| | - Sandra H. Vaz
- Instituto de Medicina Molecular João Lobo Antunes, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
- Instituto de Farmacologia e Neurociências, Faculdade de Medicina, Universidade de Lisboa, Lisbon, Portugal
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Zhu X, Liu H, Wang D, Guan R, Zou Y, Li M, Zhang J, Chen J. NLRP3 deficiency protects against hypobaric hypoxia induced neuroinflammation and cognitive dysfunction. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2023; 255:114828. [PMID: 36989949 DOI: 10.1016/j.ecoenv.2023.114828] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/07/2022] [Revised: 03/21/2023] [Accepted: 03/22/2023] [Indexed: 06/19/2023]
Abstract
As increasing number of people migrated to high altitude, highland encephalopathy and hypoxia-induced cognitive impairment arouse public attention. Yet, its underlying mechanisms remain unclear. Emerging evidence has implied neuroinflammation and neuronal loss may be involved. In the present study, we investigated the neuroinflammation and neuronal loss in mice after hypoxic insult. Our reports showed hypobaric hypoxia exposure for 3 weeks led to impaired spatial exploration and short-term memory in mice, concomitant with neuron loss. In addition, hypoxia induced neuroinflammation and NLRP3 inflammasome activation. Besides, to explore the role of the inflammasome in hypoxia-induced cognitive dysfunction, NLRP3 knockout mice were applied and the results showed that NLRP3 could negatively regulate GPX4 to modify antioxidant capacity. In summary, our work demonstrated that hypoxia exposure led to neuroinflammation and neuronal-deletion, which may be the key events in the process of hypoxia induced cognitive impairment. NLRP3 inflammasome promoted antioxidant deficiency by negatively regulating GPX4.
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Affiliation(s)
- Xiaozheng Zhu
- Tianjin Institute of Environmental and Operational Medicine, China
| | - Huiping Liu
- School of Medicine, Quzhou College of Technology, China
| | - Diya Wang
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, China
| | - Ruili Guan
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, China
| | - Yuankang Zou
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, China
| | - Ming Li
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, China
| | - Jianbin Zhang
- Department of Occupational and Environmental Health and the Ministry of Education Key Lab of Hazard Assessment and Control in Special Operational Environment, School of Public Health, Fourth Military Medical University, China.
| | - Jingyuan Chen
- Tianjin Institute of Environmental and Operational Medicine, China.
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Puzio M, Moreton N, Sullivan M, Scaife C, Glennon JC, O'Connor JJ. An Electrophysiological and Proteomic Analysis of the Effects of the Superoxide Dismutase Mimetic, MnTMPyP, on Synaptic Signalling Post-Ischemia in Isolated Rat Hippocampal Slices. Antioxidants (Basel) 2023; 12:antiox12040792. [PMID: 37107167 PMCID: PMC10135248 DOI: 10.3390/antiox12040792] [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: 02/28/2023] [Revised: 03/17/2023] [Accepted: 03/21/2023] [Indexed: 04/29/2023] Open
Abstract
Metabolic stress and the increased production of reactive oxygen species (ROS) are two main contributors to neuronal damage and synaptic plasticity in acute ischemic stroke. The superoxide scavenger MnTMPyP has been previously reported to have a neuroprotective effect in organotypic hippocampal slices and to modulate synaptic transmission after in vitro hypoxia and oxygen-glucose deprivation (OGD). However, the mechanisms involved in the effect of this scavenger remain elusive. In this study, two concentrations of MnTMPyP were evaluated on synaptic transmission during ischemia and post-ischemic synaptic potentiation. The complex molecular changes supporting cellular adaptation to metabolic stress, and how these are modulated by MnTMPyP, were also investigated. Electrophysiological data showed that MnTMPyP causes a decrease in baseline synaptic transmission and impairment of synaptic potentiation. Proteomic analysis performed on MnTMPyP and hypoxia-treated tissue indicated an impairment in vesicular trafficking mechanisms, including reduced expression of Hsp90 and actin signalling. Alterations of vesicular trafficking may lead to reduced probability of neurotransmitter release and AMPA receptor activity, resulting in the observed modulatory effect of MnTMPyP. In OGD, protein enrichment analysis highlighted impairments in cell proliferation and differentiation, such as TGFβ1 and CDKN1B signalling, in addition to downregulation of mitochondrial dysfunction and an increased expression of CAMKII. Taken together, our results may indicate modulation of neuronal sensitivity to the ischemic insult, and a complex role for MnTMPyP in synaptic transmission and plasticity, potentially providing molecular insights into the mechanisms mediating the effects of MnTMPyP during ischemia.
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Affiliation(s)
- Martina Puzio
- UCD School of Biomolecular & Biomedical Science, University College Dublin, Dublin 4, Ireland
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Niamh Moreton
- UCD School of Biomolecular & Biomedical Science, University College Dublin, Dublin 4, Ireland
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Mairéad Sullivan
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
- UCD School of Medicine, University College Dublin, Dublin 4, Ireland
| | - Caitriona Scaife
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
| | - Jeffrey C Glennon
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
- UCD School of Medicine, University College Dublin, Dublin 4, Ireland
| | - John J O'Connor
- UCD School of Biomolecular & Biomedical Science, University College Dublin, Dublin 4, Ireland
- Mass Spectrometry Core Facility, UCD Conway Institute of Biomolecular & Biomedical Research, University College Dublin, Dublin 4, Ireland
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Arias-Cavieres A, Garcia AJ. A Consequence of Immature Breathing induces Persistent Changes in Hippocampal Synaptic Plasticity and Behavior: A Role of Pro-Oxidant State and NMDA Receptor Imbalance. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.03.21.533692. [PMID: 36993632 PMCID: PMC10055328 DOI: 10.1101/2023.03.21.533692] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Indexed: 04/13/2023]
Abstract
Underdeveloped breathing results from premature birth and causes intermittent hypoxia during the early neonatal period. Neonatal intermittent hypoxia (nIH) is a condition linked to the increased risk of neurocognitive deficit later in life. However, the underlying mechanistic consequences nIH-induced neurophysiological changes remains poorly resolved. Here, we investigated the impact of nIH on hippocampal synaptic plasticity and NMDA receptor (NMDAr) expression in neonatal mice. Our findings indicate that nIH induces a pro-oxidant state, leading to an imbalance in NMDAr subunit composition that favors GluN2A over GluN2B expression, and subsequently impairs synaptic plasticity. These consequences persist in adulthood and coincide with deficits in spatial memory. Treatment with the antioxidant, manganese(III) tetrakis(1-methyl-4-pyridyl)porphyrin (MnTMPyP), during nIH effectively mitigated both immediate and long-term effects of nIH. However, MnTMPyP treatment post-nIH did not prevent the long-lasting changes in either synaptic plasticity or behavior. Our results underscore the central role of the pro-oxidant state in nIH-mediated neurophysiological and behavioral deficits and importance of stable oxygen homeostasis during early life. These findings suggest that targeting the pro-oxidant state during a discrete window may provide a potential avenue for mitigating long-term neurophysiological and behavioral outcomes when breathing is unstable during early postnatal life. Highlights Untreated immature breathing leads neonatal intermittent hypoxia (nIH).nIH promotes a pro-oxidant state associated with increased HIF1a activity and NOX upregulation.nIH-dependent pro-oxidant state leads to NMDAr remodeling of the GluN2 subunit to impair synaptic plasticity.Impaired synaptic plasticity and NMDAr remodeling caused by nIH persists beyond the critical period of development.A discrete window for antioxidant administration exists to effectively mitigate neurophysiological and behavioral consequences of nIH.
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Affiliation(s)
- Alejandra Arias-Cavieres
- Institute for Integrative Physiology, The University of Chicago
- Department of Medicine, Section of Emergency Medicine, The University of Chicago
| | - Alfredo J. Garcia
- Institute for Integrative Physiology, The University of Chicago
- Grossman Institute for Neuroscience, Quantitative Biology & Human Behavior, The University of Chicago
- Department of Medicine, Section of Emergency Medicine, The University of Chicago
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Marciante AB, Howard J, Kelly MN, Santiago Moreno J, Allen LL, Gonzalez-Rothi EJ, Mitchell GS. Dose-dependent phosphorylation of endogenous Tau by intermittent hypoxia in rat brain. J Appl Physiol (1985) 2022; 133:561-571. [PMID: 35861520 PMCID: PMC9448341 DOI: 10.1152/japplphysiol.00332.2022] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 07/11/2022] [Accepted: 07/13/2022] [Indexed: 11/22/2022] Open
Abstract
Intermittent hypoxia, or intermittent low oxygen interspersed with normal oxygen levels, has differential effects that depend on the "dose" of hypoxic episodes (duration, severity, number per day, and number of days). Whereas "low dose" daily acute intermittent hypoxia (dAIH) elicits neuroprotection and neuroplasticity, "high dose" chronic intermittent hypoxia (CIH) similar to that experienced during sleep apnea elicits neuropathology. Sleep apnea is comorbid in >50% of patients with Alzheimer's disease-a progressive, neurodegenerative disease associated with brain amyloid and chronic Tau dysregulation (pathology). Although patients with sleep apnea present with higher Tau levels, it is unknown if sleep apnea through attendant CIH contributes to onset of Tau pathology. We hypothesized CIH characteristic of moderate sleep apnea would increase dysregulation of phosphorylated Tau (phospho-Tau) species in Sprague-Dawley rat hippocampus and prefrontal cortex. Conversely, we hypothesized that dAIH, a promising neurotherapeutic, has minimal impact on Tau phosphorylation. We report a dose-dependent intermittent hypoxia effect, with region-specific increases in 1) phospho-Tau species associated with human Tauopathies in the soluble form and 2) accumulated phospho-Tau in the insoluble fraction. The latter observation was particularly evident with higher CIH intensities. This important and novel finding is consistent with the idea that sleep apnea and attendant CIH have the potential to accelerate the progression of Alzheimer's disease and/or other Tauopathies.NEW & NOTEWORTHY Sleep apnea is highly prevalent in people with Alzheimer's disease, suggesting the potential to accelerate disease onset and/or progression. These studies demonstrate that intermittent hypoxia (IH) induces dose-dependent, region-specific Tau phosphorylation, and are the first to indicate that higher IH "doses" elicit both endogenous, (rat) Tau hyperphosphorylation and accumulation in the hippocampus. These findings are essential for development and implementation of new treatment strategies that minimize sleep apnea and its adverse impact on neurodegenerative diseases.
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Affiliation(s)
- Alexandria B Marciante
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, Florida
- Department of Physical Therapy, University of Florida, Gainesville, Florida
- McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - John Howard
- Department of Neuroscience, University of Florida, Gainesville, Florida
- Center for Translational Research in Neurodegenerative Diseases, University of Florida, Gainesville, Florida
| | - Mia N Kelly
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, Florida
- Department of Physical Therapy, University of Florida, Gainesville, Florida
- McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Juan Santiago Moreno
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, Florida
- Department of Physical Therapy, University of Florida, Gainesville, Florida
- McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Latoya L Allen
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, Florida
- Department of Physical Therapy, University of Florida, Gainesville, Florida
- McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Elisa J Gonzalez-Rothi
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, Florida
- Department of Physical Therapy, University of Florida, Gainesville, Florida
- McKnight Brain Institute, University of Florida, Gainesville, Florida
| | - Gordon S Mitchell
- Breathing Research and Therapeutics Center, University of Florida, Gainesville, Florida
- Department of Physical Therapy, University of Florida, Gainesville, Florida
- McKnight Brain Institute, University of Florida, Gainesville, Florida
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Moreton N, Puzio M, O’Connor JJ. The effects of the superoxide dismutase mimetic, MnTMPyP, post hypoxia and oxygen glucose deprivation, in isolated rat hippocampal slices. Brain Res Bull 2022; 190:105-115. [DOI: 10.1016/j.brainresbull.2022.09.021] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/16/2022] [Revised: 08/17/2022] [Accepted: 09/27/2022] [Indexed: 11/02/2022]
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11
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Hillman TC, Idnani R, Wilson CG. An Inexpensive Open-Source Chamber for Controlled Hypoxia/Hyperoxia Exposure. Front Physiol 2022; 13:891005. [PMID: 35903067 PMCID: PMC9315218 DOI: 10.3389/fphys.2022.891005] [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: 03/07/2022] [Accepted: 06/08/2022] [Indexed: 11/18/2022] Open
Abstract
Understanding hypoxia/hyperoxia exposure requires either a high-altitude research facility or a chamber in which gas concentrations are precisely and reproducibly controlled. Hypoxia-induced conditions such as hypoxic-ischemic encephalopathy (HIE), obstructive or central apneas, and ischemic stroke present unique challenges for the development of models with acute or chronic hypoxia exposure. Many murine models exist to study these conditions; however, there are a variety of different hypoxia exposure protocols used across laboratories. Experimental equipment for hypoxia exposure typically includes flow regulators, nitrogen concentrators, and premix oxygen/nitrogen tanks. Commercial hypoxia/hyperoxia chambers with environmental monitoring are incredibly expensive and require proprietary software with subscription fees or highly expensive software licenses. Limitations exist in these systems as most are single animal systems and not designed for extended or intermittent hypoxia exposure. We have developed a simple hypoxia chamber with off-the-shelf components, and controlled by open-source software for continuous data acquisition of oxygen levels and other environmental factors (temperature, humidity, pressure, light, sound, etc.). Our chamber can accommodate up to two mouse cages and one rat cage at any oxygen level needed, when using a nitrogen concentrator or premixed oxygen/nitrogen tank with a flow regulator, but is also scalable. Our system uses a Python-based script to save data in a text file using modules from the sensor vendor. We utilized Python or R scripts for data analysis, and we have provided examples of data analysis scripts and acquired data for extended exposure periods (≤7 days). By using FLOS (Free-Libre and open-source) software and hardware, we have developed a low-cost and customizable system that can be used for a variety of exposure protocols. This hypoxia/hyperoxia exposure chamber allows for reproducible and transparent data acquisition and increased consistency with a high degree of customization for each experimenter’s needs.
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Affiliation(s)
- Tyler C. Hillman
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda, CA, United States
| | - Ryan Idnani
- Department of Bioengineering, College of Engineering, University of California, Berkeley, CA, United States
| | - Christopher G. Wilson
- Lawrence D. Longo, MD Center for Perinatal Biology, Loma Linda, CA, United States
- Department of Pediatrics, School of Medicine, Loma Linda University Medical Center Loma Linda University, Loma Linda, CA, United States
- *Correspondence: Christopher G. Wilson,
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12
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Editorial: Intermittent hypoxia. Exp Neurol 2021; 348:113951. [PMID: 34955452 DOI: 10.1016/j.expneurol.2021.113951] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
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