1
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Kuznetsov AV. Effects of Time-Dependent Adenosine Triphosphate Consumption Caused by Neuron Firing on Adenosine Triphosphate Concentrations in Synaptic Boutons Containing and Lacking a Stationary Mitochondrion. J Biomech Eng 2024; 146:111002. [PMID: 38888293 DOI: 10.1115/1.4065743] [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: 02/20/2024] [Accepted: 06/10/2024] [Indexed: 06/20/2024]
Abstract
The precise mechanism behind the supply of adenosine triphosphate (ATP) to approximately half of the presynaptic release sites in axons that lack a stationary mitochondrion is not fully understood. This paper presents a mathematical model designed to simulate the transient ATP concentration in presynaptic en passant boutons. The model is utilized to investigate how the ATP concentration responds to increased ATP demand during neuronal firing in boutons with a stationary mitochondrion and those without one. The analysis suggests that neuron firing may cause oscillations in the ATP concentrations, with peak-to-peak amplitudes ranging from 0.06% to 5% of their average values. However, this does not deplete boutons lacking a mitochondrion of ATP; for physiologically relevant values of model parameters, their concentration remains approximately 3.75 times higher than the minimum concentration required for synaptic activity. The variance in average ATP concentrations between boutons containing a stationary mitochondrion and those lacking one ranges from 0.3% to 0.8%, contingent on the distance between the boutons. The model indicates that diffusion-driven ATP transport is rapid enough to adequately supply ATP molecules to boutons lacking a stationary mitochondrion.
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Affiliation(s)
- Andrey V Kuznetsov
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, NC 27695-7910
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2
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Igamberdiev AU. Reflexive neural circuits and the origin of language and music codes. Biosystems 2024; 246:105346. [PMID: 39349135 DOI: 10.1016/j.biosystems.2024.105346] [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: 08/07/2024] [Revised: 09/23/2024] [Accepted: 09/26/2024] [Indexed: 10/02/2024]
Abstract
Conscious activity is grounded in the reflexive self-awareness in sense perception, through which the codes signifying sensual perceptive events operate and constrain human behavior. These codes grow via the creative generation of hypertextual statements. We apply the model of Vladimir Lefebvre (Lefebvre, V.A., 1987, J. Soc. Biol. Struct. 10, 129-175) to reveal the underlying structures on which the perception and creative development of language and music codes are based. According to this model, the reflexive structure of conscious subject is grounded in three thermodynamic cycles united by the control of the basic functional cycle by the second one, and resulting in the internal action that it turn is perceived by the third cycle evaluating this action. In this arrangement, the generative language structures are formed and the frequencies of sounds that form musical phrases and patterns are selected. We discuss the participation of certain neural brain structures and the establishment of reflexive neural circuits in the ad hoc transformation of perceptive signals, and show the similarities between the processes of perception and of biological self-maintenance and morphogenesis. We trace the peculiarities of the temporal encoding of emotions in music and musical creativity, as well as the principles of sharing musical information between the performing and the perceiving individuals.
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Affiliation(s)
- Abir U Igamberdiev
- Department of Biology, Memorial University of Newfoundland, St. John's, NL A1C 5S7, Canada.
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3
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Kadamani KL, Rahnamaie-Tajadod R, Eaton L, Bengtsson J, Ojaghi M, Cheng H, Pamenter ME. What can naked mole-rats teach us about ameliorating hypoxia-related human diseases? Ann N Y Acad Sci 2024. [PMID: 39269277 DOI: 10.1111/nyas.15219] [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] [Indexed: 09/15/2024]
Abstract
Ameliorating the deleterious impact of systemic or tissue-level hypoxia or ischemia is key to preventing or treating many human diseases and pathologies. Usefully, environmental hypoxia is also a common challenge in many natural habitats; animals that are native to such hypoxic niches often exhibit strategies that enable them to thrive with limited O2 availability. Studying how such species have evolved to tolerate systemic hypoxia offers a promising avenue of discovery for novel strategies to mitigate the deleterious effects of hypoxia in human diseases and pathologies. Of particular interest are naked mole-rats, which are among the most hypoxia-tolerant mammals. Naked mole-rats that tolerate severe hypoxia in a laboratory setting are also protected against clinically relevant mimics of heart attack and stroke. The mechanisms that support this tolerance are currently being elucidated but results to date suggest that metabolic rate suppression, reprogramming of metabolic pathways, and mechanisms that defend against deleterious perturbations of cellular signaling pathways all provide layers of protection. Herein, we synthesize and discuss what is known regarding adaptations to hypoxia in the naked mole-rat cardiopulmonary system and brain, as these systems comprise both the primary means of delivering O2 to tissues and the most hypoxia-sensitive organs in mammals.
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Affiliation(s)
- Karen L Kadamani
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | | | - Liam Eaton
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - John Bengtsson
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Mohammad Ojaghi
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
| | - Hang Cheng
- Department of Cellular and Molecular Medicine, University of Ottawa, Ottawa, Ontario, Canada
| | - Matthew E Pamenter
- Department of Biology, University of Ottawa, Ottawa, Ontario, Canada
- University of Ottawa Brain and Mind Research Institute, Ottawa, Ontario, Canada
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4
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Malkin J, O'Donnell C, Houghton CJ, Aitchison L. Signatures of Bayesian inference emerge from energy-efficient synapses. eLife 2024; 12:RP92595. [PMID: 39106188 DOI: 10.7554/elife.92595] [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: 08/09/2024] Open
Abstract
Biological synaptic transmission is unreliable, and this unreliability likely degrades neural circuit performance. While there are biophysical mechanisms that can increase reliability, for instance by increasing vesicle release probability, these mechanisms cost energy. We examined four such mechanisms along with the associated scaling of the energetic costs. We then embedded these energetic costs for reliability in artificial neural networks (ANNs) with trainable stochastic synapses, and trained these networks on standard image classification tasks. The resulting networks revealed a tradeoff between circuit performance and the energetic cost of synaptic reliability. Additionally, the optimised networks exhibited two testable predictions consistent with pre-existing experimental data. Specifically, synapses with lower variability tended to have (1) higher input firing rates and (2) lower learning rates. Surprisingly, these predictions also arise when synapse statistics are inferred through Bayesian inference. Indeed, we were able to find a formal, theoretical link between the performance-reliability cost tradeoff and Bayesian inference. This connection suggests two incompatible possibilities: evolution may have chanced upon a scheme for implementing Bayesian inference by optimising energy efficiency, or alternatively, energy-efficient synapses may display signatures of Bayesian inference without actually using Bayes to reason about uncertainty.
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Affiliation(s)
- James Malkin
- Faculty of Engineering, University of Bristol, Bristol, United Kingdom
| | - Cian O'Donnell
- Faculty of Engineering, University of Bristol, Bristol, United Kingdom
- Intelligent Systems Research Centre, School of Computing, Engineering, and Intelligent Systems, Ulster University, Derry/Londonderry, United Kingdom
| | - Conor J Houghton
- Faculty of Engineering, University of Bristol, Bristol, United Kingdom
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5
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Xu W, Borges K. Case for supporting astrocyte energetics in glucose transporter 1 deficiency syndrome. Epilepsia 2024; 65:2213-2226. [PMID: 38767952 DOI: 10.1111/epi.18013] [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: 02/01/2024] [Revised: 04/30/2024] [Accepted: 05/02/2024] [Indexed: 05/22/2024]
Abstract
In glucose transporter 1 deficiency syndrome (Glut1DS), glucose transport into brain is reduced due to impaired Glut1 function in endothelial cells at the blood-brain barrier. This can lead to shortages of glucose in brain and is thought to contribute to seizures. Ketogenic diets are the first-line treatment and, among many beneficial effects, provide auxiliary fuel in the form of ketone bodies that are largely metabolized by neurons. However, Glut1 is also the main glucose transporter in astrocytes. Here, we review data indicating that glucose shortage may also impact astrocytes in addition to neurons and discuss the expected negative biochemical consequences of compromised astrocytic glucose transport for neurons. Based on these effects, auxiliary fuels are needed for both cell types and adding medium chain triglycerides (MCTs) to ketogenic diets is a biochemically superior treatment for Glut1DS compared to classical ketogenic diets. MCTs provide medium chain fatty acids (MCFAs), which are largely metabolized by astrocytes and not neurons. MCFAs supply energy and contribute carbons for glutamine and γ-aminobutyric acid synthesis, and decanoic acid can also block α-amino-3-hydroxy-5-methyl-4-isoxazolepropionic acid glutamate receptors. MCTs do not compete with metabolism of ketone bodies mostly occurring in neurons. Triheptanoin, an anaplerotic but also gluconeogenic uneven MCT, may be another potential addition to ketogenic diets, although maintenance of "ketosis" can be difficult. Gene therapy has also targeted both endothelial cells and astrocytes. Other approaches to increase fuel delivery to the brain currently investigated include exchange of Glut1DS erythrocytes with healthy cells, infusion of lactate, and pharmacological improvement of glucose transport. In conclusion, although it remains difficult to assess impaired astrocytic energy metabolism in vivo, astrocytic energy needs are most likely not met by ketogenic diets in Glut1DS. Thus, we propose prospective studies including monitoring of blood MCFA levels to find optimal doses for add-on MCT to ketogenic diets and assessing of short- and long-term outcomes.
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Affiliation(s)
- Weizhi Xu
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland, Australia
| | - Karin Borges
- School of Biomedical Sciences, University of Queensland, St Lucia, Queensland, Australia
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6
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Hu Y, Zhang L, Tian C, Chen F, Li P, Zhang A, Wang W. Molecular crosstalk and putative mechanisms underlying mitochondrial quality control: The hidden link with methylmercury-induced cognitive impairment. ECOTOXICOLOGY AND ENVIRONMENTAL SAFETY 2024; 278:116360. [PMID: 38678690 DOI: 10.1016/j.ecoenv.2024.116360] [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: 01/22/2024] [Revised: 04/04/2024] [Accepted: 04/19/2024] [Indexed: 05/01/2024]
Abstract
Methylmercury (MeHg) is a neurotoxin associated with foetal neurodevelopmental and adult cognitive deficits. Neurons are highly dependent on the tricarboxylic acid cycle and oxidative phosphorylation to produce ATP and meet their high energy demands. Therefore, mitochondrial quality control (MQC) is critical for neuronal homeostasis. While existing studies have generated a wealth of data on the toxicity of MeHg, the complex cascades and molecular pathways governing the mitochondrial network remain to be elucidated. Here, 0.6, 1.2 and 2.4 mg/kg body weight of MeHg were administered intragastrically to pregnant Sprague Dawley rats to model maternal MeHg exposure. The results of the in vivo study revealed that MeHg-treated rats tended to perform more directionless repetitive strategies in the Morris Water Maze and fewer target-orientation strategies than control offspring. Moreover, pathological injury and synaptic toxicity were observed in the hippocampus. Transmission electron microscopy (TEM) demonstrated that the autophagosomes encapsulated damaged mitochondria, while showing a typical mitochondrial fission phenotype, which was supported by the activation of PINK1-dependent key regulators of mitophagy. Moreover, there was upregulation of DRP1 and FIS1. Additionally, MeHg compensation promoted mitochondrial biogenesis, as evidenced by the activation of the mitochondrial PGC1-α-NRF1-TFAM signalling pathway. Notably, SIRT3/AMPK was activated by MeHg, and the expression and activity of p-AMPK, p-LKB1 and SIRT3 were consistently coordinated. Collectively, these findings provide new insights into the potential molecular mechanisms regulating MeHg-induced cognitive deficits through SIRT3/AMPK MQC network coordination.
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Affiliation(s)
- Yi Hu
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Li Zhang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Changsong Tian
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Fang Chen
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China
| | - Ping Li
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China; State Key Laboratory of Environmental Geochemistry, Institute of Geochemistry, Chinese Academy of Sciences, Guiyang 550081, China
| | - Aihua Zhang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China; Collaborative Innovation Centre for Prevention and Control of Endemic and Ethnic Regional Diseases Co-constructed by the Province and Ministry, Guizhou Medical University, Guiyang 550025, China.
| | - Wenjuan Wang
- The Key Laboratory of Environmental Pollution Monitoring and Disease Control, Ministry of Education, School of Public Health, Guizhou Medical University, Guiyang 550025, China; Collaborative Innovation Centre for Prevention and Control of Endemic and Ethnic Regional Diseases Co-constructed by the Province and Ministry, Guizhou Medical University, Guiyang 550025, China.
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7
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Borsley S, Leigh DA, Roberts BMW. Molecular Ratchets and Kinetic Asymmetry: Giving Chemistry Direction. Angew Chem Int Ed Engl 2024; 63:e202400495. [PMID: 38568047 DOI: 10.1002/anie.202400495] [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: 01/12/2024] [Indexed: 05/03/2024]
Abstract
Over the last two decades ratchet mechanisms have transformed the understanding and design of stochastic molecular systems-biological, chemical and physical-in a move away from the mechanical macroscopic analogies that dominated thinking regarding molecular dynamics in the 1990s and early 2000s (e.g. pistons, springs, etc), to the more scale-relevant concepts that underpin out-of-equilibrium research in the molecular sciences today. Ratcheting has established molecular nanotechnology as a research frontier for energy transduction and metabolism, and has enabled the reverse engineering of biomolecular machinery, delivering insights into how molecules 'walk' and track-based synthesisers operate, how the acceleration of chemical reactions enables energy to be transduced by catalysts (both motor proteins and synthetic catalysts), and how dynamic systems can be driven away from equilibrium through catalysis. The recognition of molecular ratchet mechanisms in biology, and their invention in synthetic systems, is proving significant in areas as diverse as supramolecular chemistry, systems chemistry, dynamic covalent chemistry, DNA nanotechnology, polymer and materials science, molecular biology, heterogeneous catalysis, endergonic synthesis, the origin of life, and many other branches of chemical science. Put simply, ratchet mechanisms give chemistry direction. Kinetic asymmetry, the key feature of ratcheting, is the dynamic counterpart of structural asymmetry (i.e. chirality). Given the ubiquity of ratchet mechanisms in endergonic chemical processes in biology, and their significance for behaviour and function from systems to synthesis, it is surely just as fundamentally important. This Review charts the recognition, invention and development of molecular ratchets, focussing particularly on the role for which they were originally envisaged in chemistry, as design elements for molecular machinery. Different kinetically asymmetric systems are compared, and the consequences of their dynamic behaviour discussed. These archetypal examples demonstrate how chemical systems can be driven inexorably away from equilibrium, rather than relax towards it.
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Affiliation(s)
- Stefan Borsley
- Department of Chemistry, The University of Manchester, Oxford Road, M13 9PL, Manchester, United Kingdom
| | - David A Leigh
- Department of Chemistry, The University of Manchester, Oxford Road, M13 9PL, Manchester, United Kingdom
| | - Benjamin M W Roberts
- Department of Chemistry, The University of Manchester, Oxford Road, M13 9PL, Manchester, United Kingdom
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8
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Sengupta A, Mishra A, Wang F, Chen LM, Gore JC. Characteristic BOLD signals are detectable in white matter of the spinal cord at rest and after a stimulus. Proc Natl Acad Sci U S A 2024; 121:e2316117121. [PMID: 38776372 PMCID: PMC11145258 DOI: 10.1073/pnas.2316117121] [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: 09/26/2023] [Accepted: 02/16/2024] [Indexed: 05/25/2024] Open
Abstract
We report the reliable detection of reproducible patterns of blood-oxygenation-level-dependent (BOLD) MRI signals within the white matter (WM) of the spinal cord during a task and in a resting state. Previous functional MRI studies have shown that BOLD signals are robustly detectable not only in gray matter (GM) in the brain but also in cerebral WM as well as the GM within the spinal cord, but similar signals in WM of the spinal cord have been overlooked. In this study, we detected BOLD signals in the WM of the spinal cord in squirrel monkeys and studied their relationships with the locations and functions of ascending and descending WM tracts. Tactile sensory stimulus -evoked BOLD signal changes were detected in the ascending tracts of the spinal cord using a general-linear model. Power spectral analysis confirmed that the amplitude at the fundamental frequency of the response to a periodic stimulus was significantly higher in the ascending tracts than the descending ones. Independent component analysis of resting-state signals identified coherent fluctuations from eight WM hubs which correspond closely to the known anatomical locations of the major WM tracts. Resting-state analyses showed that the WM hubs exhibited correlated signal fluctuations across spinal cord segments in reproducible patterns that correspond well with the known neurobiological functions of WM tracts in the spinal cord. Overall, these findings provide evidence of a functional organization of intraspinal WM tracts and confirm that they produce hemodynamic responses similar to GM both at baseline and under stimulus conditions.
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Affiliation(s)
- Anirban Sengupta
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37235
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN37235
| | - Arabinda Mishra
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37235
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN37235
| | - Feng Wang
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37235
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN37235
| | - Li Min Chen
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37235
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN37235
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN37235
| | - John C. Gore
- Vanderbilt University Institute of Imaging Science, Vanderbilt University Medical Center, Nashville, TN37235
- Department of Radiology and Radiological Sciences, Vanderbilt University Medical Center, Nashville, TN37235
- Department of Biomedical Engineering, Vanderbilt University, Nashville, TN37235
- Department of Physics and Astronomy, Vanderbilt University, Nashville, TN37235
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9
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Chen H, Zeng Y, Wang D, Li Y, Xing J, Zeng Y, Liu Z, Zhou X, Fan H. Neuroinflammation of Microglial Regulation in Alzheimer's Disease: Therapeutic Approaches. Molecules 2024; 29:1478. [PMID: 38611758 PMCID: PMC11013124 DOI: 10.3390/molecules29071478] [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: 02/04/2024] [Revised: 03/13/2024] [Accepted: 03/23/2024] [Indexed: 04/14/2024] Open
Abstract
Alzheimer's disease (AD) is a complex degenerative disease of the central nervous system that is clinically characterized by a progressive decline in memory and cognitive function. The pathogenesis of AD is intricate and not yet fully understood. Neuroinflammation, particularly microglial activation-mediated neuroinflammation, is believed to play a crucial role in increasing the risk, triggering the onset, and hastening the progression of AD. Modulating microglial activation and regulating microglial energy metabolic disorder are seen as promising strategies to intervene in AD. The application of anti-inflammatory drugs and the targeting of microglia for the prevention and treatment of AD has emerged as a new area of research interest. This article provides a comprehensive review of the role of neuroinflammation of microglial regulation in the development of AD, exploring the connection between microglial energy metabolic disorder, neuroinflammation, and AD development. Additionally, the advancements in anti-inflammatory and microglia-regulating therapies for AD are discussed.
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Affiliation(s)
- Haiyun Chen
- College of Pharmacy, Clinical Pharmacy (School of Integrative Pharmacy), Guangdong Pharmaceutical University, Guangzhou 510006, China; (H.C.)
| | - Yuhan Zeng
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangzhou 510006, China; (Y.Z.)
- Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou 510006, China
- Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Guangzhou 510006, China
- Key Unit of Modulating Liver to Treat Hyperlipemia SATCM, State Administration of Traditional Chinese Medicine, Guangzhou 510006, China
| | - Dan Wang
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangzhou 510006, China; (Y.Z.)
- Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou 510006, China
- Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Guangzhou 510006, China
- Key Unit of Modulating Liver to Treat Hyperlipemia SATCM, State Administration of Traditional Chinese Medicine, Guangzhou 510006, China
| | - Yichen Li
- Guangdong Provincial Key Laboratory of Research and Development of Natural Drugs, School of Pharmacy, Guangdong Medical University, Zhanjiang 524023, China;
| | - Jieyu Xing
- College of Pharmacy, Clinical Pharmacy (School of Integrative Pharmacy), Guangdong Pharmaceutical University, Guangzhou 510006, China; (H.C.)
| | - Yuejia Zeng
- College of Pharmacy, Clinical Pharmacy (School of Integrative Pharmacy), Guangdong Pharmaceutical University, Guangzhou 510006, China; (H.C.)
| | - Zheng Liu
- School of Medicine, Foshan University, Foshan 528000, China;
| | - Xinhua Zhou
- Guangzhou Eighth People’s Hospital, Guangzhou Medical University, Guangzhou 510000, China
| | - Hui Fan
- Guangdong Metabolic Diseases Research Center of Integrated Chinese and Western Medicine, Guangzhou 510006, China; (Y.Z.)
- Guangdong TCM Key Laboratory for Metabolic Diseases, Guangzhou 510006, China
- Key Laboratory of Glucolipid Metabolic Disorder, Ministry of Education of China, Guangzhou 510006, China
- Key Unit of Modulating Liver to Treat Hyperlipemia SATCM, State Administration of Traditional Chinese Medicine, Guangzhou 510006, China
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10
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Jin H, Liu A, Chin AC, Fu C, Shen H, Cheng W. Deleting IP6K1 stabilizes neuronal sodium-potassium pumps and suppresses excitability. Mol Brain 2024; 17:8. [PMID: 38350944 PMCID: PMC10863101 DOI: 10.1186/s13041-024-01080-y] [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: 12/18/2023] [Accepted: 01/31/2024] [Indexed: 02/15/2024] Open
Abstract
Inositol pyrophosphates are key signaling molecules that regulate diverse neurobiological processes. We previously reported that the inositol pyrophosphate 5-InsP7, generated by inositol hexakisphosphate kinase 1 (IP6K1), governs the degradation of Na+/K+-ATPase (NKA) via an autoinhibitory domain of PI3K p85α. NKA is required for maintaining electrochemical gradients for proper neuronal firing. Here we characterized the electrophysiology of IP6K1 knockout (KO) neurons to further expand upon the functions of IP6K1-regulated control of NKA stability. We found that IP6K1 KO neurons have a lower frequency of action potentials and a specific deepening of the afterhyperpolarization phase. Our results demonstrate that deleting IP6K1 suppresses neuronal excitability, which is consistent with hyperpolarization due to an enrichment of NKA. Given that impaired NKA function contributes to the pathophysiology of various neurological diseases, including hyperexcitability in epilepsy, our findings may have therapeutic implications.
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Affiliation(s)
- Hongfu Jin
- Department of Nuclear Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China
| | - Aili Liu
- Department of Cellular Biology, School of Basic Science, Tianjin Medical University, Tianjin, China
| | - Alfred C Chin
- The Solomon H. Snyder Department of Neuroscience, Johns Hopkins University School of Medicine, Baltimore, MD, USA
- Weill Cornell/Rockefeller/Sloan Kettering Tri-Institutional MD-PhD Program, New York, NY, USA
| | - Chenglai Fu
- Institute for Developmental and Regenerative Cardiovascular Medicine, Xinhua Hospital, School of Medicine, Shanghai Jiao Tong University, Shanghai, China
| | - Hui Shen
- Department of Cellular Biology, School of Basic Science, Tianjin Medical University, Tianjin, China.
| | - Weiwei Cheng
- Department of Nuclear Medicine, Xinhua Hospital Affiliated to Shanghai Jiao Tong University School of Medicine, Shanghai, China.
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11
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Wulaer B, Holtz MA, Nagai J. Homeostasis to Allostasis: Prefrontal Astrocyte Roles in Cognitive Flexibility and Stress Biology. ADVANCES IN NEUROBIOLOGY 2024; 39:137-163. [PMID: 39190074 DOI: 10.1007/978-3-031-64839-7_6] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/28/2024]
Abstract
In the intricate landscape of neurophysiology, astrocytes have been traditionally cast as homeostatic cells; however, their mechanistic involvement in allostasis-particularly how they modulate the adaptive response to stress and its accumulative impact that disrupts cognitive functions and precipitates psychiatric disorders-is now starting to be unraveled. Here, we address the gap by positing astrocytes as crucial allostatic players whose molecular adaptations underlie cognitive flexibility in stress-related neuropsychiatric conditions. We review how astrocytes, responding to stress mediators such as glucocorticoid and epinephrine/norepinephrine, undergo morphological and functional transformations that parallel the maladaptive changes. Our synthesis of recent findings reveals that these glial changes, especially in the metabolically demanding prefrontal cortex, may underlie some of the neuropsychiatric mechanisms characterized by the disruption of energy metabolism and astrocytic networks, compromised glutamate clearance, and diminished synaptic support. We argue that astrocytes extend beyond their homeostatic role, actively participating in the brain's allostatic response, especially by modulating energy substrates critical for cognitive functions.
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Affiliation(s)
- Bolati Wulaer
- Laboratory for Glia-Neuron Circuit Dynamics, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Mika A Holtz
- Laboratory for Glia-Neuron Circuit Dynamics, RIKEN Center for Brain Science, Wako, Saitama, Japan
| | - Jun Nagai
- Laboratory for Glia-Neuron Circuit Dynamics, RIKEN Center for Brain Science, Wako, Saitama, Japan.
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12
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Zhang Y, Sun M, Zhao H, Wang Z, Shi Y, Dong J, Wang K, Wang X, Li X, Qi H, Zhao X. Neuroprotective Effects and Therapeutic Potential of Dichloroacetate: Targeting Metabolic Disorders in Nervous System Diseases. Int J Nanomedicine 2023; 18:7559-7581. [PMID: 38106446 PMCID: PMC10725694 DOI: 10.2147/ijn.s439728] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2023] [Accepted: 11/28/2023] [Indexed: 12/19/2023] Open
Abstract
Dichloroacetate (DCA) is an investigational drug used to treat lactic acidosis and malignant tumours. It works by inhibiting pyruvate dehydrogenase kinase and increasing the rate of glucose oxidation. Some studies have documented the neuroprotective benefits of DCA. By reviewing these studies, this paper shows that DCA has multiple pharmacological activities, including regulating metabolism, ameliorating oxidative stress, attenuating neuroinflammation, inhibiting apoptosis, decreasing autophagy, protecting the blood‒brain barrier, improving the function of endothelial progenitor cells, improving mitochondrial dynamics, and decreasing amyloid β-protein. In addition, DCA inhibits the enzyme that metabolizes it, which leads to peripheral neurotoxicity due to drug accumulation that may be solved by individualized drug delivery and nanovesicle delivery. In summary, in this review, we analyse the mechanisms of neuroprotection by DCA in different diseases and discuss the causes of and solutions to its adverse effects.
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Affiliation(s)
- Yue Zhang
- Department of Radiation Oncology and Shandong Provincial Key Laboratory of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, People’s Republic of China
- Laboratory of Anesthesia and Critical Care Medicine in Colleges and Universities of Shandong Province, School of Anesthesiology, Weifang Medical University, Weifang, Shandong Province, People’s Republic of China
| | - Meiyan Sun
- Laboratory of Anesthesia and Critical Care Medicine in Colleges and Universities of Shandong Province, School of Anesthesiology, Weifang Medical University, Weifang, Shandong Province, People’s Republic of China
| | - Hongxiang Zhao
- Department of Radiation Oncology and Shandong Provincial Key Laboratory of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, People’s Republic of China
- Laboratory of Anesthesia and Critical Care Medicine in Colleges and Universities of Shandong Province, School of Anesthesiology, Weifang Medical University, Weifang, Shandong Province, People’s Republic of China
| | - Zhengyan Wang
- Laboratory of Anesthesia and Critical Care Medicine in Colleges and Universities of Shandong Province, School of Anesthesiology, Weifang Medical University, Weifang, Shandong Province, People’s Republic of China
| | - Yanan Shi
- Laboratory of Anesthesia and Critical Care Medicine in Colleges and Universities of Shandong Province, School of Anesthesiology, Weifang Medical University, Weifang, Shandong Province, People’s Republic of China
| | - Jianxin Dong
- Laboratory of Anesthesia and Critical Care Medicine in Colleges and Universities of Shandong Province, School of Anesthesiology, Weifang Medical University, Weifang, Shandong Province, People’s Republic of China
| | - Kaifang Wang
- Department of Anesthesia, Tangdu Hospital, Fourth Military Medical University, Xian, Shanxi Province, People’s Republic of China
| | - Xi Wang
- Department of Anesthesiology, Sir Run Run Shaw Hospital, School of Medicine, Zhejiang University, Hangzhou, Zhejiang Province, People’s Republic of China
| | - Xingyue Li
- Department of Hepatobiliary and Pancreatic Surgery, Affiliated Hospital of Weifang Medical University, Weifang, Shandong Province, People’s Republic of China
| | - Haiyan Qi
- Department of Anesthesiology, Jinan Maternity and Child Care Hospital Affiliated to Shandong First Medical University, Jinan, Shandong Province, People’s Republic of China
| | - Xiaoyong Zhao
- Department of Radiation Oncology and Shandong Provincial Key Laboratory of Radiation Oncology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong, People’s Republic of China
- Laboratory of Anesthesia and Critical Care Medicine in Colleges and Universities of Shandong Province, School of Anesthesiology, Weifang Medical University, Weifang, Shandong Province, People’s Republic of China
- Department of Anesthesiology, Shandong Cancer Hospital and Institute, Shandong First Medical University and Shandong Academy of Medical Sciences, Jinan, Shandong Province, People’s Republic of China
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13
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Stoll EA. A thermodynamical model of non-deterministic computation in cortical neural networks. Phys Biol 2023; 21:016003. [PMID: 38078366 DOI: 10.1088/1478-3975/ad0f2d] [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: 10/27/2023] [Accepted: 11/23/2023] [Indexed: 12/18/2023]
Abstract
Neuronal populations in the cerebral cortex engage in probabilistic coding, effectively encoding the state of the surrounding environment with high accuracy and extraordinary energy efficiency. A new approach models the inherently probabilistic nature of cortical neuron signaling outcomes as a thermodynamic process of non-deterministic computation. A mean field approach is used, with the trial Hamiltonian maximizing available free energy and minimizing the net quantity of entropy, compared with a reference Hamiltonian. Thermodynamic quantities are always conserved during the computation; free energy must be expended to produce information, and free energy is released during information compression, as correlations are identified between the encoding system and its surrounding environment. Due to the relationship between the Gibbs free energy equation and the Nernst equation, any increase in free energy is paired with a local decrease in membrane potential. As a result, this process of thermodynamic computation adjusts the likelihood of each neuron firing an action potential. This model shows that non-deterministic signaling outcomes can be achieved by noisy cortical neurons, through an energy-efficient computational process that involves optimally redistributing a Hamiltonian over some time evolution. Calculations demonstrate that the energy efficiency of the human brain is consistent with this model of non-deterministic computation, with net entropy production far too low to retain the assumptions of a classical system.
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Affiliation(s)
- Elizabeth A Stoll
- Western Institute for Advanced Study, Denver, Colorado, United States of America
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14
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Sun XR, Yao ZM, Chen L, Huang J, Dong SY. Metabolic reprogramming regulates microglial polarization and its role in cerebral ischemia reperfusion. Fundam Clin Pharmacol 2023; 37:1065-1078. [PMID: 37339781 DOI: 10.1111/fcp.12928] [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: 08/14/2022] [Revised: 05/12/2023] [Accepted: 06/07/2023] [Indexed: 06/22/2023]
Abstract
The brain is quite sensitive to changes in energy supply because of its high energetic demand. Even small changes in energy metabolism may be the basis of impaired brain function, leading to the occurrence and development of cerebral ischemia/reperfusion (I/R) injury. Abundant evidence supports that metabolic defects of brain energy during the post-reperfusion period, especially low glucose oxidative metabolism and elevated glycolysis levels, which play a crucial role in cerebral I/R pathophysiology. Whereas research on brain energy metabolism dysfunction under the background of cerebral I/R mainly focuses on neurons, the research on the complexity of microglia energy metabolism in cerebral I/R is just emerging. As resident immune cells of the central nervous system, microglia activate rapidly and then transform into an M1 or M2 phenotype to correspond to changes in brain homeostasis during cerebral I/R injury. M1 microglia release proinflammatory factors to promote neuroinflammation, while M2 microglia play a neuroprotective role by secreting anti-inflammatory factors. The abnormal brain microenvironment promotes the metabolic reprogramming of microglia, which further affects the polarization state of microglia and disrupts the dynamic equilibrium of M1/M2, resulting in the aggravation of cerebral I/R injury. Increasing evidence suggests that metabolic reprogramming is a key driver of microglial inflammation. For example, M1 microglia preferentially produce energy through glycolysis, while M2 microglia provide energy primarily through oxidative phosphorylation. In this review, we highlight the emerging significance of regulating microglial energy metabolism in cerebral I/R injury.
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Affiliation(s)
- Xiao-Rong Sun
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China
| | - Zi-Meng Yao
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China
| | - Lei Chen
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China
| | - Jie Huang
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China
| | - Shu-Ying Dong
- Department of Pharmacology, School of Pharmacy, Bengbu Medical College, Bengbu, China
- Bengbu Medical College Key Laboratory of Cardiovascular and Cerebrovascular Diseases, Bengbu, China
- Anhui Engineering Technology Research Center of Biochemical Pharmaceutical, Bengbu, China
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15
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Soustelle L, Aimond F, López-Andrés C, Brugioti V, Raoul C, Layalle S. ALS-Associated KIF5A Mutation Causes Locomotor Deficits Associated with Cytoplasmic Inclusions, Alterations of Neuromuscular Junctions, and Motor Neuron Loss. J Neurosci 2023; 43:8058-8072. [PMID: 37748861 PMCID: PMC10669773 DOI: 10.1523/jneurosci.0562-23.2023] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Revised: 09/12/2023] [Accepted: 09/13/2023] [Indexed: 09/27/2023] Open
Abstract
Amyotrophic lateral sclerosis (ALS) is a fatal neurodegenerative disease affecting motor neurons. Recently, genome-wide association studies identified KIF5A as a new ALS-causing gene. KIF5A encodes a protein of the kinesin-1 family, allowing the anterograde transport of cargos along the microtubule rails in neurons. In ALS patients, mutations in the KIF5A gene induce exon 27 skipping, resulting in a mutated protein with a new C-terminal region (KIF5A Δ27). To understand how KIF5A Δ27 underpins the disease, we developed an ALS-associated KIF5A Drosophila model. When selectively expressed in motor neurons, KIF5A Δ27 alters larval locomotion as well as morphology and synaptic transmission at neuromuscular junctions in both males and females. We show that the distribution of mitochondria and synaptic vesicles is profoundly disturbed by KIF5A Δ27 expression. That is consistent with the numerous KIF5A Δ27-containing inclusions observed in motor neuron soma and axons. Moreover, KIF5A Δ27 expression leads to motor neuron death and reduces life expectancy. Our in vivo model reveals that a toxic gain of function underlies the pathogenicity of ALS-linked KIF5A mutant.SIGNIFICANCE STATEMENT Understanding how a mutation identified in patients with amyotrophic lateral sclerosis (ALS) causes the disease and the loss of motor neurons is crucial to fight against this disease. To this end, we have created a Drosophila model based on the motor neuron expression of the KIF5A mutant gene, recently identified in ALS patients. KIF5A encodes a kinesin that allows the anterograde transport of cargos. This model recapitulates the main features of ALS, including alterations of locomotion, synaptic neurotransmission, and morphology at neuromuscular junctions, as well as motor neuron death. KIF5A mutant is found in cytoplasmic inclusions, and its pathogenicity is because of a toxic gain of function.
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Affiliation(s)
- Laurent Soustelle
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Franck Aimond
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Cristina López-Andrés
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Véronique Brugioti
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Cédric Raoul
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
| | - Sophie Layalle
- Institute for Neurosciences Montpellier, Université Montpellier, Institut National de la Santé et de la Recherche Médicale, Montpellier, 34091, France
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16
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St-Pierre MK, González Ibáñez F, Kroner A, Tremblay MÈ. Microglia/macrophages are ultrastructurally altered by their proximity to spinal cord injury in adult female mice. J Neuroinflammation 2023; 20:273. [PMID: 37990235 PMCID: PMC10664529 DOI: 10.1186/s12974-023-02953-0] [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: 07/28/2023] [Accepted: 11/08/2023] [Indexed: 11/23/2023] Open
Abstract
Traumatic spinal cord injury can cause immediate physical damage to the spinal cord and result in severe neurological deficits. The primary, mechanical tissue damage triggers a variety of secondary damage mechanisms at the injury site which significantly contribute to a larger lesion size and increased functional damage. Inflammatory mechanisms which directly involve both microglia (MG) and monocyte-derived macrophages (MDM) play important roles in the post-injury processes, including inflammation and debris clearing. In the current study, we investigated changes in the structure and function of MG/MDM in the injured spinal cord of adult female mice, 7 days after a thoracic contusion SCI. With the use of chip mapping scanning electron microscopy, which allows to image large samples at the nanoscale, we performed an ultrastructural comparison of MG/MDM located near the lesion vs adjacent regions to provide novel insights into the mechanisms at play post-injury. We found that MG/MDM located near the lesion had more mitochondria overall, including mitochondria with and without morphological alterations, and had a higher proportion of altered mitochondria. MG/MDM near the lesion also showed an increased number of phagosomes, including phagosomes containing myelin and partiallydigested materials. MG/MDM near the injury interacted differently with the spinal cord parenchyma, as shown by their reduced number of direct contacts with synaptic elements, axon terminals and dendritic spines. In this study, we characterized the ultrastructural changes of MG/MDM in response to spinal cord tissue damage in mice, uncovering changes in phagocytic activity, mitochondrial ultrastructure, and inter-cellular interactions within the spinal cord parenchyma.
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Affiliation(s)
- Marie-Kim St-Pierre
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada
| | - Fernando González Ibáñez
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada
- Division of Medical Sciences, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada
| | - Antje Kroner
- Department of Neurosurgery, Medical College of Wisconsin, Milwaukee, WI, USA.
- Department of Microbiology and Immunology, Medical College of Wisconsin, Milwaukee, WI, USA.
- Clement J. Zablocki Veterans Affairs Medical Center, 5000 W. National Ave, Milwaukee, WI, 53295, USA.
| | - Marie-Ève Tremblay
- Axe Neurosciences, Centre de Recherche du CHU de Québec-Université Laval, Québec City, QC, Canada.
- Department of Molecular Medicine, Université Laval, Québec City, QC, Canada.
- Division of Medical Sciences, University of Victoria, 3800 Finnerty Road, Victoria, BC, V8P 5C2, Canada.
- Department of Biochemistry and Molecular Biology, The University of British Columbia, Vancouver, BC, Canada.
- Department of Neurology and Neurosurgery, McGill University, Montréal, QC, Canada.
- Centre for Advanced Materials and Related Technology (CAMTEC) and Institute on Aging and Lifelong Health (IALH), University of Victoria, Victoria, BC, Canada.
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Wang J, Zhang W, Xu H, Ellenbroek B, Dai J, Wang L, Yan C, Wang W. The Changes of Histone Methylation Induced by Adolescent Social Stress Regulate the Resting-State Activity in mPFC. RESEARCH (WASHINGTON, D.C.) 2023; 6:0264. [PMID: 38434244 PMCID: PMC10907022 DOI: 10.34133/research.0264] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 03/28/2023] [Accepted: 10/15/2023] [Indexed: 03/05/2024]
Abstract
Early-life stress can lead to sustained alterations in regional resting-state brain functions, but the underlying molecular mechanism remains unclear. Stress can also induce sustained changes in epigenetic modifications across brain regions, which are not limited to a few genes; rather, they often tend to produce global levels of change. The functional implication of these changes also remains to be elucidated. We hypothesize that global epigenetic changes may partly modulate the resting-state functions of brain regions to influence behavior. To test this hypothesis, we used an adolescent social stress (ASS) model in mice and examined the relationship between epigenetic modifications and regional resting-state brain activity using resting-state functional magnetic resonance imaging (rs-fMRI). The results showed that, compared to the control mice, the stressed mice showed increased anxiety and social avoidance behaviors and greater levels of dimethylation of histone H3 at lysine 9 (H3K9me2) in the medial prefrontal cortex (mPFC). In addition, the resting-state activity represented by the amplitude of low-frequency fluctuation (ALFF) was significantly lower in the mPFC of stressed mice. To verify the relationship of H3K9me2 and ALFF, the specific inhibition of H3Kme2 was performed by using the drug UNC0642, which reversed the anxiety behavior induced by ASS and significantly increase the ALFF value of mPFC in both normal and ASS animals. Our study is the first to report an association between histone modifications and rs-fMRI findings, providing a new perspective for understanding of the significance of regional brain epigenetic changes and a possible molecular explanation for rs-fMRI findings.
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Affiliation(s)
- Jiesi Wang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Wei Zhang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Hang Xu
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Bart Ellenbroek
- School of Psychology, Victoria University of Wellington, Kelburn, Wellington 6012, New Zealand
| | - Jiajie Dai
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Li Wang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
| | - Chaogan Yan
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
| | - Weiwen Wang
- CAS Key Laboratory of Mental Health, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
- Department of Psychology, University of Chinese Academy of Sciences, Beijing, China
- CAS Key Laboratory of Behavioral Science, Institute of Psychology, Chinese Academy of Sciences, Beijing, China
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18
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Huang YQ, Gu X, Chen X, Du YT, Chen BC, Sun FY. BMECs Ameliorate High Glucose-Induced Morphological Aberrations and Synaptic Dysfunction via VEGF-Mediated Modulation of Glucose Uptake in Cortical Neurons. Cell Mol Neurobiol 2023; 43:3575-3592. [PMID: 37418138 PMCID: PMC10477237 DOI: 10.1007/s10571-023-01366-0] [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: 01/07/2023] [Accepted: 05/23/2023] [Indexed: 07/08/2023]
Abstract
It has been demonstrated that diabetes cause neurite degeneration in the brain and cognitive impairment and neurovascular interactions are crucial for maintaining brain function. However, the role of vascular endothelial cells in neurite outgrowth and synaptic formation in diabetic brain is still unclear. Therefore, present study investigated effects of brain microvascular endothelial cells (BMECs) on high glucose (HG)-induced neuritic dystrophy using a coculture model of BMECs with neurons. Multiple immunofluorescence labelling and western blot analysis were used to detect neurite outgrowth and synapsis formation, and living cell imaging was used to detect uptake function of neuronal glucose transporters. We found cocultured with BMECs significantly reduced HG-induced inhibition of neurites outgrowth (including length and branch formation) and delayed presynaptic and postsynaptic development, as well as reduction of neuronal glucose uptake capacity, which was prevented by pre-treatment with SU1498, a vascular endothelial growth factor (VEGF) receptor antagonist. To analyse the possible mechanism, we collected BMECs cultured condition medium (B-CM) to treat the neurons under HG culture condition. The results showed that B-CM showed the same effects as BMEC on HG-treated neurons. Furthermore, we observed VEGF administration could ameliorate HG-induced neuronal morphology aberrations. Putting together, present results suggest that cerebral microvascular endothelial cells protect against hyperglycaemia-induced neuritic dystrophy and restorate neuronal glucose uptake capacity by activation of VEGF receptors and endothelial VEGF release. This result help us to understand important roles of neurovascular coupling in pathogenesis of diabetic brain, providing a new strategy to study therapy or prevention for diabetic dementia. Hyperglycaemia induced inhibition of neuronal glucose uptake and impaired to neuritic outgrowth and synaptogenesis. Cocultured with BMECs/B-CM and VEGF treatment protected HG-induced inhibition of glucose uptake and neuritic outgrowth and synaptogenesis, which was antagonized by blockade of VEGF receptors. Reduction of glucose uptake may further deteriorate impairment of neurites outgrowth and synaptogenesis.
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Affiliation(s)
- Yu-Qi Huang
- Department of Neurobiology and Research Institute for Aging and Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, 138 Yi-Xue-Yuan Road, Shanghai, 200032, People's Republic of China
- National Clinical Research Center for Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai, 200032, People's Republic of China
| | - Xiao Gu
- Department of Neurobiology and Research Institute for Aging and Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, 138 Yi-Xue-Yuan Road, Shanghai, 200032, People's Republic of China
- National Clinical Research Center for Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai, 200032, People's Republic of China
| | - Xiao Chen
- Department of Neurobiology and Research Institute for Aging and Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, 138 Yi-Xue-Yuan Road, Shanghai, 200032, People's Republic of China
- National Clinical Research Center for Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai, 200032, People's Republic of China
| | - Yi-Ting Du
- Department of Neurobiology and Research Institute for Aging and Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, 138 Yi-Xue-Yuan Road, Shanghai, 200032, People's Republic of China
- National Clinical Research Center for Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai, 200032, People's Republic of China
| | - Bin-Chi Chen
- Department of Neurobiology and Research Institute for Aging and Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, 138 Yi-Xue-Yuan Road, Shanghai, 200032, People's Republic of China
- National Clinical Research Center for Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai, 200032, People's Republic of China
| | - Feng-Yan Sun
- Department of Neurobiology and Research Institute for Aging and Medicine, School of Basic Medical Sciences, Shanghai Medical College, Fudan University, 138 Yi-Xue-Yuan Road, Shanghai, 200032, People's Republic of China.
- National Clinical Research Center for Aging and Medicine, Shanghai Medical College, Fudan University, Shanghai, 200032, People's Republic of China.
- Shanghai Key Laboratory of Bioactive Small Molecules, School of Basic Medical Sciences, Institute of Biomedical Sciences, Shanghai Medical College, Fudan University, Shanghai, 200032, People's Republic of China.
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19
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Hemida M, Rosendahl S, Jokinen TS, Moore R, Vuori KA, Anturaniemi J, Hielm-Björkman A. Assessing the association between supplemented puppyhood dietary fat sources and owner-reported epilepsy in adulthood, among Finnish companion dogs. Front Vet Sci 2023; 10:1227437. [PMID: 37781290 PMCID: PMC10540444 DOI: 10.3389/fvets.2023.1227437] [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: 05/23/2023] [Accepted: 08/25/2023] [Indexed: 10/03/2023] Open
Abstract
Introduction Epilepsy is a serious and common neurological condition in dogs, despite the wide number of antiepileptic drugs available, in approximately one third of the patients, epilepsy remains unsatisfactorily controlled. We aim to analyze whether feeding dietary fat sources during puppyhood was associated with canine epilepsy in adulthood. Methods A nested case-control study was compiled from the validated DogRisk food frequency questionnaire (DogRisk FFQ). DogRisk FFQ collected feeding, disease, and background data about the dog. The study sample consisted of 108 owner-reported epileptic cases and 397 non-epileptic controls. Each case was matched with up to four controls for the key confounding factors of sex, breed, and age. We analyzed associations between feeding as a puppy and owner-reported epilepsy as an adult dog using Cox regression. We tested 55 different food variables. Results We found that feeding fish fat from dietary sources at least once a week during puppyhood was inversely associated with epilepsy in later life in the unadjusted analysis [OR 0.46 (95% CI 0.25-0.83), p=0.01], while when adjusting for keeping conditions and dog characteristics the association was [OR 0.45 (95% CI 0.23-0.88), p=0.02]. When adjusted for keeping conditions, dog characteristics, and other feeding factors, the association was of similar magnitude but not significance [OR 0.56 (95% CI 0.27-1.15), p=0.12]. Discussion The study indicates possible protective associations of feeding the dog with dietary sources of fish fat against epilepsy, although the result could be confounded by other feeding factors. Findings are compatible with current knowledge regarding the role of omega-3 fatty acids and ketogenic diet, a low carbohydrate, high fat diet as supportive treatments of epilepsy. As our findings are based on observations, we suggest the possibility of causality but do not prove it. Dietary intervention studies should now be conducted to confirm our findings.
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Affiliation(s)
- Manal Hemida
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
- Department of Nutrition and Clinical Nutrition, Faculty of Veterinary Medicine, Beni-Suef University, Beni Suef, Egypt
| | - Sarah Rosendahl
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Tarja S. Jokinen
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Robin Moore
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Kristiina A. Vuori
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Johanna Anturaniemi
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
| | - Anna Hielm-Björkman
- Department of Equine and Small Animal Medicine, Faculty of Veterinary Medicine, University of Helsinki, Helsinki, Finland
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20
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Karanikas E. The Gordian knot of the immune-redox systems' interactions in psychosis. Int Clin Psychopharmacol 2023; 38:285-296. [PMID: 37351570 DOI: 10.1097/yic.0000000000000481] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 06/24/2023]
Abstract
During the last decades the attempt to enlighten the pathobiological substrate of psychosis, from merely focusing on neurotransmitters, has expanded into new areas like the immune and redox systems. Indeed, the inflammatory hypothesis concerning psychosis etiopathology has exponentially grown with findings reflecting dysfunction/aberration of the immune/redox systems' effector components namely cytokines, chemokines, CRP, complement system, antibodies, pro-/anti-oxidants, oxidative stress byproducts just to name a few. Yet, we still lie far from comprehending the underlying cellular mechanisms, their causality directions, and the moderating/mediating parameters affecting these systems; let alone the inter-systemic (between immune and redox) interactions. Findings from preclinical studies on the stress field have provided evidence indicative of multifaceted interactions among the immune and redox components so tightly intertwined as a Gordian knot. Interestingly the literature concerning the interactions between these same systems in the context of psychosis appears minimal (if not absent) and ambiguous. This review attempts to draw a frame of the immune-redox systems' interactions starting from basic research on the stress field and expanding on clinical studies with cohorts with psychosis, hoping to instigate new avenues of research.
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Affiliation(s)
- Evangelos Karanikas
- Department of Psychiatry, 424 General Military Hospital, Ring Road, Nea Efkarpia, Thessaloniki, Greece
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21
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Holland SM, Gallo G. Actin cytoskeletal dynamics do not impose an energy drain on growth cone bioenergetics. J Cell Sci 2023; 136:jcs261356. [PMID: 37534394 PMCID: PMC10445737 DOI: 10.1242/jcs.261356] [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: 05/23/2023] [Accepted: 07/26/2023] [Indexed: 08/04/2023] Open
Abstract
The regulation of the intracellular level of ATP is a fundamental aspect of bioenergetics. Actin cytoskeletal dynamics have been reported to be an energetic drain in developing neurons and platelets. We addressed the role of actin dynamics in primary embryonic chicken neurons using luciferase assays, and by measurement of the ATP/ADP ratio using the ratiometric reporter PercevalHR and the ATP level using the ratiometric reporter mRuby-iATPSnFR. None of the methods revealed an effect of suppressing actin dynamics on the decline in the neuronal ATP level or the ATP/ADP ratio following shutdown of ATP production. Similarly, we find that treatments that elevate or suppress actin dynamics do not alter the ATP/ADP ratio in growth cones, the subcellular domain with the highest actin dynamics in developing neurons. Collectively, the data indicate that actin cytoskeletal dynamics are not a significant energy drain in developing neurons and that the ATP/ADP ratio is maintained when energy utilization varies. Discrepancies between prior work and the current data are discussed with emphasis on methodology and interpretation of the data.
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Affiliation(s)
- Sabrina M. Holland
- Lewis Katz School of Medicine at Temple University, Department of Neural Sciences, Shriners Pediatric Research Center, 3500 North Broad St, Philadelphia, PA 19140, USA
| | - Gianluca Gallo
- Lewis Katz School of Medicine at Temple University, Department of Neural Sciences, Shriners Pediatric Research Center, 3500 North Broad St, Philadelphia, PA 19140, USA
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22
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Raut S, Bhalerao A, Powers M, Gonzalez M, Mancuso S, Cucullo L. Hypometabolism, Alzheimer's Disease, and Possible Therapeutic Targets: An Overview. Cells 2023; 12:2019. [PMID: 37626828 PMCID: PMC10453773 DOI: 10.3390/cells12162019] [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: 05/17/2023] [Revised: 07/19/2023] [Accepted: 08/06/2023] [Indexed: 08/27/2023] Open
Abstract
The brain is a highly dynamic organ that requires a constant energy source to function normally. This energy is mostly supplied by glucose, a simple sugar that serves as the brain's principal fuel source. Glucose transport across the blood-brain barrier (BBB) is primarily controlled via sodium-independent facilitated glucose transport, such as by glucose transporter 1 (GLUT1) and 3 (GLUT3). However, other glucose transporters, including GLUT4 and the sodium-dependent transporters SGLT1 and SGLT6, have been reported in vitro and in vivo. When the BBB endothelial layer is crossed, neurons and astrocytes can absorb the glucose using their GLUT1 and GLUT3 transporters. Glucose then enters the glycolytic pathway and is metabolized into adenosine triphosphate (ATP), which supplies the energy to support cellular functions. The transport and metabolism of glucose in the brain are impacted by several medical conditions, which can cause neurological and neuropsychiatric symptoms. Alzheimer's disease (AD), Parkinson's disease (PD), epilepsy, traumatic brain injury (TBI), schizophrenia, etc., are a few of the most prevalent disorders, characterized by a decline in brain metabolism or hypometabolism early in the course of the disease. Indeed, AD is considered a metabolic disorder related to decreased brain glucose metabolism, involving brain insulin resistance and age-dependent mitochondrial dysfunction. Although the conventional view is that reduced cerebral metabolism is an effect of neuronal loss and consequent brain atrophy, a growing body of evidence points to the opposite, where hypometabolism is prodromal or at least precedes the onset of brain atrophy and the manifestation of clinical symptoms. The underlying processes responsible for these glucose transport and metabolic abnormalities are complicated and remain poorly understood. This review article provides a comprehensive overview of the current understanding of hypometabolism in AD and potential therapeutic targets.
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Affiliation(s)
- Snehal Raut
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, USA; (S.R.); (A.B.); (M.G.); (S.M.)
| | - Aditya Bhalerao
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, USA; (S.R.); (A.B.); (M.G.); (S.M.)
| | - Michael Powers
- Department of Biological and Biomedical Sciences, Oakland University, Rochester, MI 48309, USA;
| | - Minelly Gonzalez
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, USA; (S.R.); (A.B.); (M.G.); (S.M.)
| | - Salvatore Mancuso
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, USA; (S.R.); (A.B.); (M.G.); (S.M.)
| | - Luca Cucullo
- Department of Foundational Medical Studies, Oakland University William Beaumont School of Medicine, Rochester, MI 48309, USA; (S.R.); (A.B.); (M.G.); (S.M.)
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Maiseli B, Abdalla AT, Massawe LV, Mbise M, Mkocha K, Nassor NA, Ismail M, Michael J, Kimambo S. Brain-computer interface: trend, challenges, and threats. Brain Inform 2023; 10:20. [PMID: 37540385 PMCID: PMC10403483 DOI: 10.1186/s40708-023-00199-3] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 07/01/2023] [Indexed: 08/05/2023] Open
Abstract
Brain-computer interface (BCI), an emerging technology that facilitates communication between brain and computer, has attracted a great deal of research in recent years. Researchers provide experimental results demonstrating that BCI can restore the capabilities of physically challenged people, hence improving the quality of their lives. BCI has revolutionized and positively impacted several industries, including entertainment and gaming, automation and control, education, neuromarketing, and neuroergonomics. Notwithstanding its broad range of applications, the global trend of BCI remains lightly discussed in the literature. Understanding the trend may inform researchers and practitioners on the direction of the field, and on where they should invest their efforts more. Noting this significance, we have analyzed 25,336 metadata of BCI publications from Scopus to determine advancement of the field. The analysis shows an exponential growth of BCI publications in China from 2019 onwards, exceeding those from the United States that started to decline during the same period. Implications and reasons for this trend are discussed. Furthermore, we have extensively discussed challenges and threats limiting exploitation of BCI capabilities. A typical BCI architecture is hypothesized to address two prominent BCI threats, privacy and security, as an attempt to make the technology commercially viable to the society.
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Affiliation(s)
- Baraka Maiseli
- Department of Electronics and Telecommunications Engineering, College of Information and Communication Technologies, University of Dar es Salaam, 14113, Dar es Salaam, Tanzania.
| | - Abdi T Abdalla
- Department of Electronics and Telecommunications Engineering, College of Information and Communication Technologies, University of Dar es Salaam, 14113, Dar es Salaam, Tanzania
| | - Libe V Massawe
- Department of Electronics and Telecommunications Engineering, College of Information and Communication Technologies, University of Dar es Salaam, 14113, Dar es Salaam, Tanzania
| | - Mercy Mbise
- Department of Computer Science and Engineering, College of Information and Communication Technologies, University of Dar es Salaam, 14113, Dar es Salaam, Tanzania
| | - Khadija Mkocha
- Department of Electronics and Telecommunications Engineering, College of Information and Communication Technologies, University of Dar es Salaam, 14113, Dar es Salaam, Tanzania
| | - Nassor Ally Nassor
- Department of Electronics and Telecommunications Engineering, College of Information and Communication Technologies, University of Dar es Salaam, 14113, Dar es Salaam, Tanzania
| | - Moses Ismail
- Department of Electronics and Telecommunications Engineering, College of Information and Communication Technologies, University of Dar es Salaam, 14113, Dar es Salaam, Tanzania
| | - James Michael
- Department of Electronics and Telecommunications Engineering, College of Information and Communication Technologies, University of Dar es Salaam, 14113, Dar es Salaam, Tanzania
| | - Samwel Kimambo
- Department of Electronics and Telecommunications Engineering, College of Information and Communication Technologies, University of Dar es Salaam, 14113, Dar es Salaam, Tanzania
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Yang S, Park JH, Lu HC. Axonal energy metabolism, and the effects in aging and neurodegenerative diseases. Mol Neurodegener 2023; 18:49. [PMID: 37475056 PMCID: PMC10357692 DOI: 10.1186/s13024-023-00634-3] [Citation(s) in RCA: 20] [Impact Index Per Article: 20.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/10/2023] [Accepted: 06/08/2023] [Indexed: 07/22/2023] Open
Abstract
Human studies consistently identify bioenergetic maladaptations in brains upon aging and neurodegenerative disorders of aging (NDAs), such as Alzheimer's disease, Parkinson's disease, Huntington's disease, and Amyotrophic lateral sclerosis. Glucose is the major brain fuel and glucose hypometabolism has been observed in brain regions vulnerable to aging and NDAs. Many neurodegenerative susceptible regions are in the topological central hub of the brain connectome, linked by densely interconnected long-range axons. Axons, key components of the connectome, have high metabolic needs to support neurotransmission and other essential activities. Long-range axons are particularly vulnerable to injury, neurotoxin exposure, protein stress, lysosomal dysfunction, etc. Axonopathy is often an early sign of neurodegeneration. Recent studies ascribe axonal maintenance failures to local bioenergetic dysregulation. With this review, we aim to stimulate research in exploring metabolically oriented neuroprotection strategies to enhance or normalize bioenergetics in NDA models. Here we start by summarizing evidence from human patients and animal models to reveal the correlation between glucose hypometabolism and connectomic disintegration upon aging/NDAs. To encourage mechanistic investigations on how axonal bioenergetic dysregulation occurs during aging/NDAs, we first review the current literature on axonal bioenergetics in distinct axonal subdomains: axon initial segments, myelinated axonal segments, and axonal arbors harboring pre-synaptic boutons. In each subdomain, we focus on the organization, activity-dependent regulation of the bioenergetic system, and external glial support. Second, we review the mechanisms regulating axonal nicotinamide adenine dinucleotide (NAD+) homeostasis, an essential molecule for energy metabolism processes, including NAD+ biosynthetic, recycling, and consuming pathways. Third, we highlight the innate metabolic vulnerability of the brain connectome and discuss its perturbation during aging and NDAs. As axonal bioenergetic deficits are developing into NDAs, especially in asymptomatic phase, they are likely exaggerated further by impaired NAD+ homeostasis, the high energetic cost of neural network hyperactivity, and glial pathology. Future research in interrogating the causal relationship between metabolic vulnerability, axonopathy, amyloid/tau pathology, and cognitive decline will provide fundamental knowledge for developing therapeutic interventions.
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Affiliation(s)
- Sen Yang
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA
| | - Jung Hyun Park
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA
| | - Hui-Chen Lu
- The Linda and Jack Gill Center for Biomolecular Sciences, Indiana University, Bloomington, IN, 47405, USA.
- Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, 47405, USA.
- Program in Neuroscience, Indiana University, Bloomington, IN, 47405, USA.
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Li L, Cheng SQ, Sun YQ, Yu JB, Huang XX, Dong YF, Ji J, Zhang XY, Hu G, Sun XL. Resolvin D1 reprograms energy metabolism to promote microglia to phagocytize neutrophils after ischemic stroke. Cell Rep 2023; 42:112617. [PMID: 37285269 DOI: 10.1016/j.celrep.2023.112617] [Citation(s) in RCA: 5] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2022] [Revised: 03/27/2023] [Accepted: 05/23/2023] [Indexed: 06/09/2023] Open
Abstract
Neutrophil aggregation and clearance are important factors affecting neuroinflammatory injury during acute ischemic stroke. Emerging evidence suggests that energy metabolism is essential for microglial functions, especially microglial phagocytosis, which determines the degree of brain injury. Here, we demonstrate that Resolvin D1 (RvD1), a lipid mediator derived from docosahexaenic acid (DHA), promotes the phagocytosis of neutrophils by microglia, thereby reducing neutrophil accumulation in the brain and alleviating neuroinflammation in the ischemic brain. Further studies reveal that RvD1 reprograms energy metabolism from glycolysis to oxidative phosphorylation (OXPHOS), providing sufficient energy for microglial phagocytosis. Moreover, RvD1 enhances microglial glutamine uptake and stimulates glutaminolysis to support OXPHOS to boost ATP production depending on adenosine 5'-monophosphate (AMP)-activated protein kinase (AMPK) activation. Overall, our results reveal that RvD1 reprograms energy metabolism to promote the microglial phagocytosis of neutrophils after ischemic stroke. These findings may guide perspectives for stroke therapy from modulating microglial immunometabolism.
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Affiliation(s)
- Lei Li
- Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
| | - Shu-Qi Cheng
- Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
| | - Yu-Qin Sun
- Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
| | - Jian-Bing Yu
- Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
| | - Xin-Xin Huang
- Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
| | - Yin-Feng Dong
- Nanjing University of Chinese Medicine, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China
| | - Juan Ji
- Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
| | - Xi-Yue Zhang
- Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
| | - Gang Hu
- Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China
| | - Xiu-Lan Sun
- Neuroprotective Drug Discovery Key Laboratory, Jiangsu Key Laboratory of Neurodegeneration, Nanjing Medical University, Nanjing, China; Nanjing University of Chinese Medicine, the Affiliated Hospital of Nanjing University of Chinese Medicine, Nanjing, China.
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26
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Austin TT, Thomas CL, Lewis C, Blockley A, Warren B. Metabolic decline in an insect ear: correlative or causative for age-related auditory decline? Front Cell Dev Biol 2023; 11:1138392. [PMID: 37274746 PMCID: PMC10233746 DOI: 10.3389/fcell.2023.1138392] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2023] [Accepted: 04/25/2023] [Indexed: 06/06/2023] Open
Abstract
One leading hypothesis for why we lose our hearing as we age is a decrease in ear metabolism. However, direct measurements of metabolism across a lifespan in any auditory system are lacking. Even if metabolism does decrease with age, a question remains: is a metabolic decrease a cause of age-related auditory decline or simply correlative? We use an insect, the desert locust Schistocerca gregaria, as a physiologically versatile model to understand how cellular metabolism correlates with age and impacts on age-related auditory decline. We found that auditory organ metabolism decreases with age as measured fluorometrically. Next, we measured the individual auditory organ's metabolic rate and its sound-evoked nerve activity and found no correlation. We found no age-related change in auditory nerve activity, using hook electrode recordings, and in the electrophysiological properties of auditory neurons, using patch-clamp electrophysiology, but transduction channel activity decreased. To further test for a causative role of the metabolic rate in auditory decline, we manipulated metabolism of the auditory organ through diet and cold-rearing but found no difference in sound-evoked nerve activity. We found that although metabolism correlates with age-related auditory decline, it is not causative. Finally, we performed RNA-Seq on the auditory organs of young and old locusts, and whilst we found enrichment for Gene Ontology terms associated with metabolism, we also found enrichment for a number of additional aging GO terms. We hypothesize that age-related hearing loss is dominated by accumulative damage in multiple cell types and multiple processes which outweighs its metabolic decline.
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Kuznetsov IA, Kuznetsov AV. ATP diffusional gradients are sufficient to maintain bioenergetic homeostasis in synaptic boutons lacking mitochondria. INTERNATIONAL JOURNAL FOR NUMERICAL METHODS IN BIOMEDICAL ENGINEERING 2023; 39:e3696. [PMID: 36872253 DOI: 10.1002/cnm.3696] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 02/16/2023] [Accepted: 02/20/2023] [Indexed: 05/13/2023]
Abstract
Previous work on mitochondrial distribution in axons has shown that approximately half of the presynaptic release sites do not contain mitochondria, raising the question of how the boutons that do not contain mitochondria are supplied with ATP. Here, we develop and apply a mathematical model to study this question. Specifically, we investigate whether diffusive transport of ATP is sufficient to support the exocytic functionality in synaptic boutons which lack mitochondria. Our results demonstrate that the difference in ATP concentration between a bouton containing a mitochondrion and a neighboring bouton lacking a mitochondrion is only approximately 0.4%, which is still 3.75 times larger than the ATP concentration minimally required to support synaptic vesicle release. This work therefore suggests that passive diffusion of ATP is sufficient to maintain the functionality of boutons which do not contain mitochondria.
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Affiliation(s)
- Ivan A Kuznetsov
- Perelman School of Medicine, University of Pennsylvania, Philadelphia, Pennsylvania, USA
- Department of Bioengineering, University of Pennsylvania, Philadelphia, Pennsylvania, USA
| | - Andrey V Kuznetsov
- Department of Mechanical and Aerospace Engineering, North Carolina State University, Raleigh, North Carolina, USA
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28
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Yu Y, Akif A, Herman P, Cao M, Rothman DL, Carson RE, Agarwal D, Evans AC, Hyder F. A 3D atlas of functional human brain energetic connectome based on neuropil distribution. Cereb Cortex 2023; 33:3996-4012. [PMID: 36104858 PMCID: PMC10068297 DOI: 10.1093/cercor/bhac322] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Revised: 07/19/2022] [Accepted: 07/20/2022] [Indexed: 11/13/2022] Open
Abstract
The human brain is energetically expensive, yet the key factors governing its heterogeneous energy distributions across cortical regions to support its diversity of functions remain unexplored. Here, we built up a 3D digital cortical energy atlas based on the energetic costs of all neuropil activities into a high-resolution stereological map of the human cortex with cellular and synaptic densities derived, respectively, from ex vivo histological staining and in vivo PET imaging. The atlas was validated with PET-measured glucose oxidation at the voxel level. A 3D cortical activity map was calculated to predict the heterogeneous activity rates across all cortical regions, which revealed that resting brain is indeed active with heterogeneous neuronal activity rates averaging around 1.2 Hz, comprising around 70% of the glucose oxidation of the cortex. Additionally, synaptic density dominates spatial patterns of energetics, suggesting that the cortical energetics rely heavily on the distribution of synaptic connections. Recent evidence from functional imaging studies suggests that some cortical areas act as hubs (i.e., interconnecting distinct and functionally active regions). An inverse allometric relationship was observed between hub metabolic rates versus hub volumes. Hubs with smaller volumes have higher synapse density, metabolic rate, and activity rates compared to nonhubs. The open-source BrainEnergyAtlas provides a granular framework for exploring revealing design principles in energy-constrained human cortical circuits across multiple spatial scales.
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Affiliation(s)
- Yuguo Yu
- Shanghai Artificial Intelligence Laboratory, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Research Institute of Intelligent and Complex Systems, Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai 200032, China
| | - Adil Akif
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
| | - Peter Herman
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
- Magnetic Resonance Research Center, Yale University, New Haven, CT 06520, USA
| | - Miao Cao
- Shanghai Artificial Intelligence Laboratory, State Key Laboratory of Medical Neurobiology and MOE Frontiers Center for Brain Science, Research Institute of Intelligent and Complex Systems, Institute of Science and Technology for Brain-Inspired Intelligence, Fudan University, Shanghai 200032, China
| | - Douglas L Rothman
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
- Magnetic Resonance Research Center, Yale University, New Haven, CT 06520, USA
| | - Richard E Carson
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
- PET Center, Yale University, New Haven, CT 06520, USA
| | - Divyansh Agarwal
- Department of Surgery, MGH, Harvard University, Boston, MA 02114, USA
| | - Alan C Evans
- Montreal Neurological Institute, McGill University, Montreal, Quebec H3A 0G4, Canada
| | - Fahmeed Hyder
- Department of Biomedical Engineering, Yale University, New Haven, CT 06520, USA
- Department of Radiology and Biomedical Imaging, Yale University, New Haven, CT 06520, USA
- Magnetic Resonance Research Center, Yale University, New Haven, CT 06520, USA
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29
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Sengupta A, Mishra A, Wang F, Chen L, Gore J. Identification of synchronous BOLD signal patterns in white matter of primate spinal cord. RESEARCH SQUARE 2023:rs.3.rs-2389151. [PMID: 36993492 PMCID: PMC10055542 DOI: 10.21203/rs.3.rs-2389151/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/23/2023]
Abstract
Functional MRI studies of the brain have shown that blood-oxygenation-level-dependent (BOLD) signals are robustly detectable not only in gray matter (GM) but also in white matter (WM). Here, we report the detection and characteristics of BOLD signals in WM of spinal cord (SC) of squirrel monkeys. Tactile stimulus-evoked BOLD signal changes were detected in the ascending sensory tracts of SC using a General-Linear Model (GLM) as well as Independent Component Analysis (ICA). ICA of resting state signals identified coherent fluctuations from eight WM hubs which correspond closely with known anatomical locations of SC WM tracts. Resting state analyses showed that the WM hubs exhibited correlated signal fluctuations within and between SC segments in specific patterns that correspond well with the known neurobiological functions of WM tracts in SC. Overall, these findings suggest WM BOLD signals in SC show similar features as GM both at baseline and under stimulus conditions.
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Affiliation(s)
| | | | - Feng Wang
- Vanderbilt University Medical Center
| | - Li Chen
- Vanderbilt University Medical Center
| | - John Gore
- Vanderbilt University Medical Center
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30
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Jeon S, Park JE, Do YH, Santos R, Lee SM, Kim BN, Cheong JH, Kim Y. Atomoxetine and Fluoxetine Activate AMPK-ACC-CPT1 Pathway in Human SH-SY5Y and U-87 MG Cells. Psychiatry Investig 2023; 20:212-219. [PMID: 36990664 PMCID: PMC10064201 DOI: 10.30773/pi.2022.0255] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 12/04/2022] [Indexed: 03/31/2023] Open
Abstract
OBJECTIVE Atomoxetine and fluoxetine are psychopharmacologic agents associated with loss of appetite and weight. Adenosine monophosphate-activated protein kinase (AMPK) is the cellular energy sensor that regulate metabolism and energy, being activated by fasting and inhibited by feeding in the hypothalamus. METHODS Human brain cell lines (SH-SY5Y and U-87 MG cells) were used to study the outcome of atomoxetine and fluoxetine treatment in the activity of AMPK-acetyl-CoA carboxylase (ACC)- carnitine palmitoyl transferase 1 (CPT1) pathway and upstream regulation by calcium/calmodulin-dependent kinase kinase β (CaMKKβ) using immunoblotting and CPT1 enzymatic activity measures. RESULTS Phosphorylation of AMPK and ACC increased significantly after atomoxetine and fluoxetine treatment in the first 30-60 minutes of treatment in the two cell lines. Activation of AMPK and inhibition of ACC was associated with an increase by 5-fold of mitochondrial CPT1 activity. Although the neuronal isoform CPT1C could be detected by immunoblotting, activity was not changed by the drug treatments. In addition, the increase in phospho-AMPK and phospho-ACC expression induced by atomoxetine was abolished by treatment with STO-609, a CaMKKβ inhibitor, indicating that AMPK-ACC-CPT1 pathway is activated through CaMKKβ phosphorylation. CONCLUSION These findings indicate that at the cellular level atomoxetine and fluoxetine treatments may activate AMPK-ACC-CPT1 pathways through CaMKKβ in human SH-SY5Y and U-87 MG cells.
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Affiliation(s)
- Songhee Jeon
- Center for Glocal Future Biomedical Scientists at Chonnam National University, Gwangju, Republic of Korea
| | - Jeong-Eun Park
- Department of Otorhinolaryngology Head and Neck Surgery, Dongtan Sacred Heart Hospital, Hallym University College of Medicine, Hwaseong, Republic of Korea
| | - Young Ho Do
- Department of Child and Adolescent Psychiatry, National Center for Mental Health, Seoul, Republic of Korea
| | - Renata Santos
- INSERM U1266, Institute of Psychiatry and Neuroscience of Paris (IPNP), Laboratory of Dynamics of Neuronal Structure in Health and Disease, Université Paris Cité, Paris, France
| | - Seong Mi Lee
- Department of Child and Adolescent Psychiatry, National Center for Mental Health, Seoul, Republic of Korea
| | - Bung-Nyun Kim
- Division of Child & Adolescent Psychiatry, Department of Psychiatry and Institute of Human Behavioral Medicine, Seoul National University College of Medicine, Seoul, Republic of Korea
| | - Jae Hoon Cheong
- Institute for New Drug Development, School of Pharmacy, Jeonbuk National University, Jeonju, Republic of Korea
| | - Yeni Kim
- Department of Child and Adolescent Psychiatry, National Center for Mental Health, Seoul, Republic of Korea
- Institute of Clinical Psychopharmacology, Dongguk University International Hospital, Goyang, Republic of Korea
- Department of Neuropsychiatry, Dongguk University School of Medicine, Goyang, Republic of Korea
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31
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Joshi SN, Joshi AN, Joshi ND. Interplay between biochemical processes and network properties generates neuronal up and down states at the tripartite synapse. Phys Rev E 2023; 107:024415. [PMID: 36932559 DOI: 10.1103/physreve.107.024415] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/10/2022] [Accepted: 01/03/2023] [Indexed: 06/18/2023]
Abstract
Neuronal up and down states have long been known to exist both in vitro and in vivo. A variety of functions and mechanisms have been proposed for their generation, but there has not been a clear connection between the functions and mechanisms. We explore the potential contribution of cellular-level biochemistry to the network-level mechanisms thought to underlie the generation of up and down states. We develop a neurochemical model of a single tripartite synapse, assumed to be within a network of similar tripartite synapses, to investigate possible function-mechanism links for the appearance of up and down states. We characterize the behavior of our model in different regions of parameter space and show that resource limitation at the tripartite synapse affects its ability to faithfully transmit input signals, leading to extinction-down states. Recovery of resources allows for "reignition" into up states. The tripartite synapse exhibits distinctive "regimes" of operation depending on whether ATP, neurotransmitter (glutamate), both, or neither, is limiting. Our model qualitatively matches the behavior of six disparate experimental systems, including both in vitro and in vivo models, without changing any model parameters except those related to the experimental conditions. We also explore the effects of varying different critical parameters within the model. Here we show that availability of energy, represented by ATP, and glutamate for neurotransmission at the cellular level are intimately related, and are capable of promoting state transitions at the network level as ignition and extinction phenomena. Our model is complementary to existing models of neuronal up and down states in that it focuses on cellular-level dynamics while still retaining essential network-level processes. Our model predicts the existence of a "final common pathway" of behavior at the tripartite synapse arising from scarcity of resources and may explain use dependence in the phenomenon of "local sleep." Ultimately, sleeplike behavior may be a fundamental property of networks of tripartite synapses.
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Affiliation(s)
- Shubhada N Joshi
- National Center for Adaptive Neurotechnologies (NCAN), David Axelrod Institute, Wadsworth Center, New York State Department of Health, 120 New Scotland Ave., Albany, New York 12208, USA
| | - Aditya N Joshi
- Stanford University School of Medicine, 300 Pasteur Dr., Stanford, California 94305, USA
| | - Narendra D Joshi
- General Electric Global Research, 1 Research Circle, Niskayuna, New York 12309, USA
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32
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Padamsey Z, Rochefort NL. Paying the brain's energy bill. Curr Opin Neurobiol 2023; 78:102668. [PMID: 36571958 DOI: 10.1016/j.conb.2022.102668] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2022] [Revised: 11/18/2022] [Accepted: 11/23/2022] [Indexed: 12/25/2022]
Abstract
How have animals managed to maintain metabolically expensive brains given the volatile and fleeting availability of calories in the natural world? Here we review studies in support of three strategies that involve: 1) a reallocation of energy from peripheral tissues and functions to cover the costs of the brain, 2) an implementation of energy-efficient neural coding, enabling the brain to operate at reduced energy costs, and 3) efficient use of costly neural resources during food scarcity. Collectively, these studies reveal a heterogeneous set of energy-saving mechanisms that make energy-costly brains fit for survival.
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Affiliation(s)
- Zahid Padamsey
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, EH8 9XD, Edinburgh, United Kingdom.
| | - Nathalie L Rochefort
- Centre for Discovery Brain Sciences, School of Biomedical Sciences, University of Edinburgh, EH8 9XD, Edinburgh, United Kingdom; Simons Initiative for the Developing Brain, University of Edinburgh, EH8 9XD, Edinburgh, United Kingdom.
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33
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Wang D, Gu X, Ma X, Chen J, Zhang Q, Yu Z, Li J, Hu M, Tan X, Tang Y, Xu J, Xu M, Song Q, Song H, Jiang G, Tang Z, Gao X, Chen H. Nanopolyphenol rejuvenates microglial surveillance of multiple misfolded proteins through metabolic reprogramming. Acta Pharm Sin B 2023; 13:834-851. [PMID: 36873190 PMCID: PMC9978858 DOI: 10.1016/j.apsb.2022.07.014] [Citation(s) in RCA: 11] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 06/14/2022] [Accepted: 06/15/2022] [Indexed: 11/25/2022] Open
Abstract
Microglial surveillance plays an essential role in clearing misfolded proteins such as amyloid-beta, tau, and α-synuclein aggregates in neurodegenerative diseases. However, due to the complex structure and ambiguous pathogenic species of the misfolded proteins, a universal approach to remove the misfolded proteins remains unavailable. Here, we found that a polyphenol, α-mangostin, reprogrammed metabolism in the disease-associated microglia through shifting glycolysis to oxidative phosphorylation, which holistically rejuvenated microglial surveillance capacity to enhance microglial phagocytosis and autophagy-mediated degradation of multiple misfolded proteins. Nanoformulation of α-mangostin efficiently delivered α-mangostin to microglia, relieved the reactive status and rejuvenated the misfolded-proteins clearance capacity of microglia, which thus impressively relieved the neuropathological changes in both Alzheimer's disease and Parkinson's disease model mice. These findings provide direct evidences for the concept of rejuvenating microglial surveillance of multiple misfolded proteins through metabolic reprogramming, and demonstrate nanoformulated α-mangostin as a potential and universal therapy against neurodegenerative diseases.
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Affiliation(s)
- Dayuan Wang
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiao Gu
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xinyi Ma
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jun Chen
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Qizhi Zhang
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Zhihua Yu
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Juan Li
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Meng Hu
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaofang Tan
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Yuyun Tang
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Jianrong Xu
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.,Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
| | - Minjun Xu
- Key Laboratory of Smart Drug Delivery, Ministry of Education, School of Pharmacy, Fudan University, Shanghai 201203, China
| | - Qingxiang Song
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Huahua Song
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Gan Jiang
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Zaiming Tang
- Key Laboratory of Cell Differentiation and Apoptosis of Chinese Ministry of Education, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Xiaoling Gao
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China
| | - Hongzhuan Chen
- Department of Pharmacology and Chemical Biology, State Key Laboratory of Oncogenes and Related Genes, Shanghai Universities Collaborative Innovation Center for Translational Medicine, Shanghai Jiao Tong University School of Medicine, Shanghai 200025, China.,Shanghai Frontiers Science Center of TCM Chemical Biology, Institute of Interdisciplinary Integrative Medicine Research, Shanghai University of Traditional Chinese Medicine, Shanghai, 201203, China
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Whitlow CT, Atcheson KM, Snively BM, Cook JF, Kim J, Haq IU, Sweadner KJ, Ozelius LJ, Brashear A. Rapid-onset dystonia-parkinsonism is associated with reduced cerebral blood flow without gray matter changes. Front Neurol 2023; 14:1116723. [PMID: 36779071 PMCID: PMC9909223 DOI: 10.3389/fneur.2023.1116723] [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: 12/05/2022] [Accepted: 01/09/2023] [Indexed: 01/27/2023] Open
Abstract
Purpose Previous research showed discrete neuropathological changes associated with rapid-onset dystonia-parkinsonism (RDP) in brains from patients with an ATP1A3 variant, specifically in areas that mediate motor function. The purpose of this study was to determine if magnetic resonance imaging methodologies could identify differences between RDP patients and variant-negative controls in areas of the brain that mediate motor function in order to provide biomarkers for future treatment or prevention trials. Methods Magnetic resonance imaging voxel-based morphometry and arterial spin labeling were used to measure gray matter volume and cerebral blood flow, respectively, in cortical motor areas, basal ganglia, thalamus, and cerebellum, in RDP patients with ATP1A3 variants (n = 19; mean age = 37 ± 14 years; 47% female) and variant-negative healthy controls (n = 11; mean age = 34 ± 19 years; 36% female). Results We report age and sex-adjusted between group differences, with decreased cerebral blood flow among patients with ATP1A3 variants compared to variant-negative controls in the thalamus (p = 0.005, Bonferroni alpha level < 0.007 adjusted for regions). There were no statistically significant between-group differences for measures of gray matter volume. Conclusions There is reduced cerebral blood flow within brain regions in patients with ATP1A3 variants within the thalamus. Additionally, the lack of corresponding gray matter volume differences may suggest an underlying functional etiology rather than structural abnormality.
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Affiliation(s)
- Christopher T. Whitlow
- Section of Neuroradiology, Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, NC, United States,Department of Biomedical Engineering, Wake Forest University School of Medicine, Winston-Salem, NC, United States,Clinical and Translational Science Institute, Wake Forest University School of Medicine, Winston-Salem, NC, United States,Department of Biostatistics and Data Science, Wake Forest University School of Medicine, Winston-Salem, NC, United States,*Correspondence: Christopher T. Whitlow ✉
| | - Kyle M. Atcheson
- Section of Neuroradiology, Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Beverly M. Snively
- Clinical and Translational Science Institute, Wake Forest University School of Medicine, Winston-Salem, NC, United States,Department of Biostatistics and Data Science, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Jared F. Cook
- Department of Psychiatry and Behavioral Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Jeongchul Kim
- Section of Neuroradiology, Department of Radiology, Wake Forest University School of Medicine, Winston-Salem, NC, United States
| | - Ihtsham U. Haq
- Department of Neurology, University of Miami, Miami, FL, United States
| | - Kathleen J. Sweadner
- Department of Neurosurgery, Massachusetts General Hospital, Boston, MA, United States
| | - Laurie J. Ozelius
- Department of Neurology, Massachusetts General Hospital, Boston, MA, United States
| | - Allison Brashear
- Department of Neurology, Jacobs School of Medicine and Biomedical Sciences, University at Buffalo, Buffalo, NY, United States
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35
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Homeostasis of carbohydrates and reactive oxygen species is critically changed in the brain of middle-aged mice: molecular mechanisms and functional reasons. BBA ADVANCES 2023; 3:100077. [PMID: 37082254 PMCID: PMC10074963 DOI: 10.1016/j.bbadva.2023.100077] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2022] [Revised: 01/19/2023] [Accepted: 01/19/2023] [Indexed: 01/23/2023] Open
Abstract
The brain is an organ that consumes a lot of energy. In the brain, energy is required for synaptic transmission, numerous biosynthetic processes and axonal transport in neurons, and for many supportive functions of glial cells. The main source of energy in the brain is glucose and to a lesser extent lactate and ketone bodies. ATP is formed at glucose catabolism via glycolysis and oxidative phosphorylation in mitochondrial electron transport chain (ETC) within mitochondria being the main source of ATP. With age, brain's energy metabolism is disturbed, involving a decrease in glycolysis and mitochondrial dysfunction. The latter is accompanied by intensified generation of reactive oxygen species (ROS) in ETC leading to oxidative stress. Recently, we have found that crucial changes in energy metabolism and intensity of oxidative stress in the mouse brain occur in middle age with minor progression in old age. In this review, we analyze the metabolic changes and functional causes that lead to these changes in the aging brain.
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36
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Cohen LD, Ziv T, Ziv NE. Synapse integrity and function: Dependence on protein synthesis and identification of potential failure points. Front Mol Neurosci 2022; 15:1038614. [PMID: 36583084 PMCID: PMC9792512 DOI: 10.3389/fnmol.2022.1038614] [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: 09/07/2022] [Accepted: 11/07/2022] [Indexed: 12/14/2022] Open
Abstract
Synaptic integrity and function depend on myriad proteins - labile molecules with finite lifetimes that need to be continually replaced with freshly synthesized copies. Here we describe experiments designed to expose synaptic (and neuronal) properties and functions that are particularly sensitive to disruptions in protein supply, identify proteins lost early upon such disruptions, and uncover potential, yet currently underappreciated failure points. We report here that acute suppressions of protein synthesis are followed within hours by reductions in spontaneous network activity levels, impaired oxidative phosphorylation and mitochondrial function, and, importantly, destabilization and loss of both excitatory and inhibitory postsynaptic specializations. Conversely, gross impairments in presynaptic vesicle recycling occur over longer time scales (days), as does overt cell death. Proteomic analysis identified groups of potentially essential 'early-lost' proteins including regulators of synapse stability, proteins related to bioenergetics, fatty acid and lipid metabolism, and, unexpectedly, numerous proteins involved in Alzheimer's disease pathology and amyloid beta processing. Collectively, these findings point to neuronal excitability, energy supply and synaptic stability as early-occurring failure points under conditions of compromised supply of newly synthesized protein copies.
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Affiliation(s)
- Laurie D. Cohen
- Technion Faculty of Medicine, Rappaport Institute and Network Biology Research Laboratories, Haifa, Israel
| | - Tamar Ziv
- Smoler Proteomics Center, Lokey Interdisciplinary Center for Life Sciences & Engineering, Technion, Haifa, Israel
| | - Noam E. Ziv
- Technion Faculty of Medicine, Rappaport Institute and Network Biology Research Laboratories, Haifa, Israel,*Correspondence: Noam E. Ziv,
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37
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Mächler P, Fomin-Thunemann N, Thunemann M, Sætra MJ, Desjardins M, Kılıç K, Amra LN, Martin EA, Chen IA, Şencan-Eğilmez I, Li B, Saisan P, Jiang JX, Cheng Q, Weldy KL, Boas DA, Buxton RB, Einevoll GT, Dale AM, Sakadžić S, Devor A. Baseline oxygen consumption decreases with cortical depth. PLoS Biol 2022; 20:e3001440. [PMID: 36301995 PMCID: PMC9642908 DOI: 10.1371/journal.pbio.3001440] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/02/2021] [Revised: 11/08/2022] [Accepted: 09/30/2022] [Indexed: 11/05/2022] Open
Abstract
The cerebral cortex is organized in cortical layers that differ in their cellular density, composition, and wiring. Cortical laminar architecture is also readily revealed by staining for cytochrome oxidase-the last enzyme in the respiratory electron transport chain located in the inner mitochondrial membrane. It has been hypothesized that a high-density band of cytochrome oxidase in cortical layer IV reflects higher oxygen consumption under baseline (unstimulated) conditions. Here, we tested the above hypothesis using direct measurements of the partial pressure of O2 (pO2) in cortical tissue by means of 2-photon phosphorescence lifetime microscopy (2PLM). We revisited our previously developed method for extraction of the cerebral metabolic rate of O2 (CMRO2) based on 2-photon pO2 measurements around diving arterioles and applied this method to estimate baseline CMRO2 in awake mice across cortical layers. To our surprise, our results revealed a decrease in baseline CMRO2 from layer I to layer IV. This decrease of CMRO2 with cortical depth was paralleled by an increase in tissue oxygenation. Higher baseline oxygenation and cytochrome density in layer IV may serve as an O2 reserve during surges of neuronal activity or certain metabolically active brain states rather than reflecting baseline energy needs. Our study provides to our knowledge the first quantification of microscopically resolved CMRO2 across cortical layers as a step towards better understanding of brain energy metabolism.
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Affiliation(s)
- Philipp Mächler
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Natalie Fomin-Thunemann
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Martin Thunemann
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Marte Julie Sætra
- Department of Numerical Analysis and Scientific Computing, Simula Research Laboratory, Oslo, Norway
| | - Michèle Desjardins
- Département de Physique, de Génie Physique et d’Optique and Axe Oncologie, Centre de Recherche du CHU de Québec–Université Laval, Université Laval, Québec, Canada
| | - Kıvılcım Kılıç
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Layth N. Amra
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Emily A. Martin
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Ichun Anderson Chen
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Ikbal Şencan-Eğilmez
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Baoqiang Li
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
| | - Payam Saisan
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
| | - John X. Jiang
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Qun Cheng
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
| | - Kimberly L. Weldy
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
| | - David A. Boas
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
| | - Richard B. Buxton
- Department of Radiology, University of California San Diego, La Jolla, California, United States of America
| | - Gaute T. Einevoll
- Department of Physics, University of Oslo, Oslo, Norway
- Department of Physics, Norwegian University of Life Sciences, Ås, Norway
| | - Anders M. Dale
- Department of Neurosciences, University of California San Diego, La Jolla, California, United States of America
- Department of Radiology, University of California San Diego, La Jolla, California, United States of America
| | - Sava Sakadžić
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- * E-mail: (SS); (AD)
| | - Anna Devor
- Department of Biomedical Engineering, Boston University, Boston, Massachusetts, United States of America
- Athinoula A. Martinos Center for Biomedical Imaging, Department of Radiology, Harvard Medical School, Massachusetts General Hospital, Charlestown, Massachusetts, United States of America
- * E-mail: (SS); (AD)
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Qi R, Wang J, Sun J, Qiu X, Liu X, Wang Q, Yang F, Ge L, Liu Z. The effects of gut microbiota colonizing on the porcine hypothalamus revealed by whole transcriptome analysis. Front Microbiol 2022; 13:970470. [PMID: 36312924 PMCID: PMC9606227 DOI: 10.3389/fmicb.2022.970470] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 09/29/2022] [Indexed: 11/13/2022] Open
Abstract
The roles of the microbe-gut-brain axis in metabolic homeostasis, development, and health are well-known. The hypothalamus integrates the higher nerve center system and functions to regulate energy balance, feeding, biological rhythms and mood. However, how the hypothalamus is affected by gut microbes in mammals is unclear. This study demonstrated differences in hypothalamic gene expression between the germ-free (GF) pigs and pigs colonized with gut microbiota (CG) by whole-transcriptome analysis. A total of 938 mRNAs, 385 lncRNAs and 42 miRNAs were identified to be differentially expressed between the two groups of pigs. An mRNA-miRNA-lncRNA competing endogenous RNA network was constructed, and miR-22-3p, miR-24-3p, miR-136-3p, miR-143-3p, and miR-545-3p located in the net hub. Gene function and pathway enrichment analysis showed the altered mRNAs were mainly related to developmental regulation, mitochondrial function, the nervous system, cell signaling and neurodegenerative diseases. Notably, the remarkable upregulation of multiple genes in oxidative phosphorylation enhanced the GF pigs’ hypothalamic energy expenditure. Additionally, the reduction in ATP content and the increase in carnitine palmitoyl transterase-1 (CPT1) protein level also confirmed this fact. Furthermore, the hypothalamic cell apoptosis rate in the CG piglets was significantly higher than that in the GF piglets. This may be due to the elevated concentrations of pro-inflammatory factors produced by gut bacteria. The obtained results collectively suggest that the colonization of gut microbes has a significant impact on hypothalamic function and health.
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Affiliation(s)
- Renli Qi
- Chongqing Academy of Animal Science, Chongqing, China
- Key Laboratory of Pig Industry Sciences, Ministry of Agriculture, Chongqing, China
- *Correspondence: Renli Qi,
| | - Jing Wang
- Chongqing Academy of Animal Science, Chongqing, China
| | - Jing Sun
- Chongqing Academy of Animal Science, Chongqing, China
| | - Xiaoyu Qiu
- Chongqing Academy of Animal Science, Chongqing, China
| | - Xin Liu
- College of Animal Science and Technology, Southwest University, Chongqing, China
| | - Qi Wang
- Chongqing Academy of Animal Science, Chongqing, China
| | - Feiyun Yang
- Chongqing Academy of Animal Science, Chongqing, China
| | - Liangpeng Ge
- Chongqing Academy of Animal Science, Chongqing, China
- Key Laboratory of Pig Industry Sciences, Ministry of Agriculture, Chongqing, China
| | - Zuohua Liu
- Chongqing Academy of Animal Science, Chongqing, China
- Key Laboratory of Pig Industry Sciences, Ministry of Agriculture, Chongqing, China
- Zuohua Liu,
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Meyer DJ, Díaz-García CM, Nathwani N, Rahman M, Yellen G. The Na +/K + pump dominates control of glycolysis in hippocampal dentate granule cells. eLife 2022; 11:e81645. [PMID: 36222651 PMCID: PMC9592084 DOI: 10.7554/elife.81645] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Accepted: 10/11/2022] [Indexed: 11/13/2022] Open
Abstract
Cellular ATP that is consumed to perform energetically expensive tasks must be replenished by new ATP through the activation of metabolism. Neuronal stimulation, an energetically demanding process, transiently activates aerobic glycolysis, but the precise mechanism underlying this glycolysis activation has not been determined. We previously showed that neuronal glycolysis is correlated with Ca2+ influx, but is not activated by feedforward Ca2+ signaling (Díaz-García et al., 2021a). Since ATP-powered Na+ and Ca2+ pumping activities are increased following stimulation to restore ion gradients and are estimated to consume most neuronal ATP, we aimed to determine if they are coupled to neuronal glycolysis activation. By using two-photon imaging of fluorescent biosensors and dyes in dentate granule cell somas of acute mouse hippocampal slices, we observed that production of cytoplasmic NADH, a byproduct of glycolysis, is strongly coupled to changes in intracellular Na+, while intracellular Ca2+ could only increase NADH production if both forward Na+/Ca2+ exchange and Na+/K+ pump activity were intact. Additionally, antidromic stimulation-induced intracellular [Na+] increases were reduced >50% by blocking Ca2+ entry. These results indicate that neuronal glycolysis activation is predominantly a response to an increase in activity of the Na+/K+ pump, which is strongly potentiated by Na+ influx through the Na+/Ca2+ exchanger during extrusion of Ca2+ following stimulation.
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Affiliation(s)
- Dylan J Meyer
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | | | - Nidhi Nathwani
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Mahia Rahman
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
| | - Gary Yellen
- Department of Neurobiology, Harvard Medical SchoolBostonUnited States
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40
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Rappe A, McWilliams TG. Mitophagy in the aging nervous system. Front Cell Dev Biol 2022; 10:978142. [PMID: 36303604 PMCID: PMC9593040 DOI: 10.3389/fcell.2022.978142] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2022] [Accepted: 09/07/2022] [Indexed: 02/01/2024] Open
Abstract
Aging is characterised by the progressive accumulation of cellular dysfunction, stress, and inflammation. A large body of evidence implicates mitochondrial dysfunction as a cause or consequence of age-related diseases including metabolic disorders, neuropathies, various forms of cancer and neurodegenerative diseases. Because neurons have high metabolic demands and cannot divide, they are especially vulnerable to mitochondrial dysfunction which promotes cell dysfunction and cytotoxicity. Mitophagy neutralises mitochondrial dysfunction, providing an adaptive quality control strategy that sustains metabolic homeostasis. Mitophagy has been extensively studied as an inducible stress response in cultured cells and short-lived model organisms. In contrast, our understanding of physiological mitophagy in mammalian aging remains extremely limited, particularly in the nervous system. The recent profiling of mitophagy reporter mice has revealed variegated vistas of steady-state mitochondrial destruction across different tissues. The discovery of patients with congenital autophagy deficiency provokes further intrigue into the mechanisms that underpin neural integrity. These dimensions have considerable implications for targeting mitophagy and other degradative pathways in age-related neurological disease.
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Affiliation(s)
- Anna Rappe
- Translational Stem Cell Biology and Metabolism Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
| | - Thomas G. McWilliams
- Translational Stem Cell Biology and Metabolism Program, Research Programs Unit, Faculty of Medicine, University of Helsinki, Helsinki, Finland
- Department of Anatomy, Faculty of Medicine, University of Helsinki, Helsinki, Finland
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von Eugen K, Endepols H, Drzezga A, Neumaier B, Güntürkün O, Backes H, Ströckens F. Avian neurons consume three times less glucose than mammalian neurons. Curr Biol 2022; 32:4306-4313.e4. [PMID: 36084646 DOI: 10.1016/j.cub.2022.07.070] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 04/11/2022] [Accepted: 07/26/2022] [Indexed: 12/14/2022]
Abstract
Brains are among the most energetically costly tissues in the mammalian body.1 This is predominantly caused by expensive neurons with high glucose demands.2 Across mammals, the neuronal energy budget appears to be fixed, possibly posing an evolutionary constraint on brain growth.3-6 Compared to similarly sized mammals, birds have higher numbers of neurons, and this advantage conceivably contributes to their cognitive prowess.7 We set out to determine the neuronal energy budget of birds to elucidate how they can metabolically support such high numbers of neurons. We estimated glucose metabolism using positron emission tomography (PET) and 2-[18F]fluoro-2-deoxyglucose ([18F]FDG) as the radiotracer in awake and anesthetized pigeons. Combined with kinetic modeling, this is the gold standard to quantify cerebral metabolic rate of glucose consumption (CMRglc).8 We found that neural tissue in the pigeon consumes 27.29 ± 1.57 μmol glucose per 100 g per min in an awake state, which translates into a surprisingly low neuronal energy budget of 1.86 × 10-9 ± 0.2 × 10-9 μmol glucose per neuron per minute. This is approximately 3 times lower than the rate in the average mammalian neuron.3 The remarkably low neuronal energy budget explains how pigeons, and possibly other avian species, can support such high numbers of neurons without associated metabolic costs or compromising neuronal signaling. The advantage in neuronal processing of information at a higher efficiency possibly emerged during the distinct evolution of the avian brain.
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Affiliation(s)
- Kaya von Eugen
- Department of Biopsychology, Institute of Cognitive Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Heike Endepols
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany; Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany; Institute of Neuroscience and Medicine, INM-5: Nuclear Chemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Alexander Drzezga
- Department of Nuclear Medicine, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany; Institute of Neuroscience and Medicine, INM-2: Molecular Organization of the Brain, Forschungszentrum Jülich GmbH, Jülich, Germany; German Center for Neurodegenerative Diseases (DZNE), Bonn-Cologne, Germany
| | - Bernd Neumaier
- Institute of Radiochemistry and Experimental Molecular Imaging, Faculty of Medicine and University Hospital of Cologne, Cologne, Germany; Institute of Neuroscience and Medicine, INM-5: Nuclear Chemistry, Forschungszentrum Jülich GmbH, Jülich, Germany
| | - Onur Güntürkün
- Department of Biopsychology, Institute of Cognitive Neuroscience, Ruhr University Bochum, Bochum, Germany
| | - Heiko Backes
- Max Planck Institute for Metabolism Research, Multimodal Imaging Group, Cologne, Germany
| | - Felix Ströckens
- Department of Biopsychology, Institute of Cognitive Neuroscience, Ruhr University Bochum, Bochum, Germany; Cécile and Oskar Vogt Institute of Brain Research, University Hospital Düsseldorf, Heinrich-Heine University, Düsseldorf, Germany.
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Leng L, Yuan Z, Pan R, Su X, Wang H, Xue J, Zhuang K, Gao J, Chen Z, Lin H, Xie W, Li H, Chen Z, Ren K, Zhang X, Wang W, Jin ZB, Wu S, Wang X, Yuan Z, Xu H, Chow HM, Zhang J. Microglial hexokinase 2 deficiency increases ATP generation through lipid metabolism leading to β-amyloid clearance. Nat Metab 2022; 4:1287-1305. [PMID: 36203054 DOI: 10.1038/s42255-022-00643-4] [Citation(s) in RCA: 41] [Impact Index Per Article: 20.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2022] [Accepted: 08/18/2022] [Indexed: 01/20/2023]
Abstract
Microglial cells consume adenosine triphosphate (ATP) during phagocytosis to clear neurotoxic β-amyloid in Alzheimer's disease (AD). However, the contribution of energy metabolism to microglial function in AD remains unclear. Here, we demonstrate that hexokinase 2 (HK2) is elevated in microglia from an AD mouse model (5xFAD) and AD patients. Genetic deletion or pharmacological inhibition of HK2 significantly promotes microglial phagocytosis, lowers the amyloid plaque burden and attenuates cognitive impairment in male AD mice. Notably, the ATP level is dramatically increased in HK2-deficient or inactive microglia, which can be attributed to a marked upregulation in lipoprotein lipase (LPL) expression and subsequent increase in lipid metabolism. We further show that two downstream metabolites of HK2, glucose-6-phosphate and fructose-6-phosphate, can reverse HK2-deficiency-induced upregulation of LPL, thus supporting ATP production and microglial phagocytosis. Our findings uncover a crucial role for HK2 in phagocytosis through regulation of microglial energy metabolism, suggesting a potential therapeutic strategy for AD by targeting HK2.
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Affiliation(s)
- Lige Leng
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China.
| | - Ziqi Yuan
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Ruiyuan Pan
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Xiao Su
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Han Wang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Jin Xue
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Kai Zhuang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Ju Gao
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Zhenlei Chen
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Hui Lin
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Wenting Xie
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Huifang Li
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Zhenyi Chen
- Department of Anesthesiology, First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China
| | - Keke Ren
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medcial University, Xi'an, Shaanxi, China
| | - Xiao Zhang
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China
| | - Wenting Wang
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medcial University, Xi'an, Shaanxi, China
| | - Zi-Bing Jin
- Beijing Institute of Ophthalmology, Beijing Tongren Eye Center, Beijing Tongren Hospital, Capital Medical University, Beijing Ophthalmology & Visual Sciences Key Lab, Beijing, China
| | - Shengxi Wu
- Department of Neurobiology, School of Basic Medicine, Fourth Military Medcial University, Xi'an, Shaanxi, China
| | - Xinglong Wang
- Department of Pathology, Case Western Reserve University, Cleveland, OH, USA
| | - Zengqiang Yuan
- The Brain Science Center, Beijing Institute of Basic Medical Sciences, Beijing, China
| | - Huaxi Xu
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China
| | - Hei-Man Chow
- School of Life Sciences, The Chinese University of Hong Kong, Sha Tin, Hong Kong
| | - Jie Zhang
- Fujian Provincial Key Laboratory of Neurodegenerative Disease and Aging Research, Institute of Neuroscience, School of Medicine, Xiamen University, Xiamen, China.
- Department of Anesthesiology, First Affiliated Hospital of Xiamen University, Xiamen, Fujian, China.
- Institute of Neuroscience, Fujian Medical University, Fuzhou, China.
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Abstract
To maintain energy supply to the brain, a direct energy source called adenosine triphosphate (ATP) is produced by oxidative phosphorylation and aerobic glycolysis of glucose in the mitochondria and cytoplasm. Brain glucose metabolism is reduced in many neurodegenerative diseases, including Alzheimer's disease (AD), where it appears presymptomatically in a progressive and region-specific manner. Following dysregulation of energy metabolism in AD, many cellular repair/regenerative processes are activated to conserve the energy required for cell viability. Glucose metabolism plays an important role in the pathology of AD and is closely associated with the tricarboxylic acid cycle, type 2 diabetes mellitus, and insulin resistance. The glucose intake in neurons is from endothelial cells, astrocytes, and microglia. Damage to neurocentric glucose also damages the energy transport systems in AD. Gut microbiota is necessary to modulate bidirectional communication between the gastrointestinal tract and brain. Gut microbiota may influence the process of AD by regulating the immune system and maintaining the integrity of the intestinal barrier. Furthermore, some therapeutic strategies have shown promising therapeutic effects in the treatment of AD at different stages, including the use of antidiabetic drugs, rescuing mitochondrial dysfunction, and epigenetic and dietary intervention. This review discusses the underlying mechanisms of alterations in energy metabolism in AD and provides potential therapeutic strategies in the treatment of AD.
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Favaretto C, Allegra M, Deco G, Metcalf NV, Griffis JC, Shulman GL, Brovelli A, Corbetta M. Subcortical-cortical dynamical states of the human brain and their breakdown in stroke. Nat Commun 2022; 13:5069. [PMID: 36038566 PMCID: PMC9424299 DOI: 10.1038/s41467-022-32304-1] [Citation(s) in RCA: 24] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/13/2021] [Accepted: 07/25/2022] [Indexed: 11/17/2022] Open
Abstract
The mechanisms controlling dynamical patterns in spontaneous brain activity are poorly understood. Here, we provide evidence that cortical dynamics in the ultra-slow frequency range (<0.01–0.1 Hz) requires intact cortical-subcortical communication. Using functional magnetic resonance imaging (fMRI) at rest, we identify Dynamic Functional States (DFSs), transient but recurrent clusters of cortical and subcortical regions synchronizing at ultra-slow frequencies. We observe that shifts in cortical clusters are temporally coincident with shifts in subcortical clusters, with cortical regions flexibly synchronizing with either limbic regions (hippocampus/amygdala), or subcortical nuclei (thalamus/basal ganglia). Focal lesions induced by stroke, especially those damaging white matter connections between basal ganglia/thalamus and cortex, provoke anomalies in the fraction times, dwell times, and transitions between DFSs, causing a bias toward abnormal network integration. Dynamical anomalies observed 2 weeks after stroke recover in time and contribute to explaining neurological impairment and long-term outcome. Favaretto et al. show that the brain rapidly alternates between transient connectivity patterns, with cortical regions flexibly synchronizing with two groups of subcortical regions, and that this dynamic is abnormal in stroke patients.
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Affiliation(s)
- Chiara Favaretto
- Padova Neuroscience Center (PNC), University of Padova, via Orus 2/B, 35129, Padova, Italy. .,Department of Neuroscience (DNS), University of Padova, via Giustiniani 2, 35128, Padova, Italy.
| | - Michele Allegra
- Padova Neuroscience Center (PNC), University of Padova, via Orus 2/B, 35129, Padova, Italy.,Department of Physics and Astronomy "Galileo Galilei", University of Padova, via Marzolo 8, 35131, Padova, Italy.,Institut de Neurosciences de la Timone UMR 7289, Aix Marseille Université, CNRS, 13005, Marseille, France
| | - Gustavo Deco
- Center for Brain and Cognition (CBC), Department of Information Technologies and Communications (DTIC), Pompeu Fabra University, Edifici Mercè Rodoreda, Carrer Trias i Fargas 25-27, 08005, Barcelona, Catalonia, Spain.,Institució Catalana de Recerca I Estudis Avançats (ICREA), Passeig Lluis Companys 23, 08010, Barcelona, Catalonia, Spain
| | - Nicholas V Metcalf
- Department of Neurology, Washington University School of Medicine, 660S. Euclid Ave, St. Louis, MO, 63110, USA
| | - Joseph C Griffis
- Department of Neurology, Washington University School of Medicine, 660S. Euclid Ave, St. Louis, MO, 63110, USA
| | - Gordon L Shulman
- Department of Neurology, Washington University School of Medicine, 660S. Euclid Ave, St. Louis, MO, 63110, USA.,Department of Radiology, Washington University School of Medicine, 660S. Euclid Ave, St. Louis, MO, 63110, USA
| | - Andrea Brovelli
- Institut de Neurosciences de la Timone UMR 7289, Aix Marseille Université, CNRS, 13005, Marseille, France
| | - Maurizio Corbetta
- Padova Neuroscience Center (PNC), University of Padova, via Orus 2/B, 35129, Padova, Italy. .,Department of Neuroscience (DNS), University of Padova, via Giustiniani 2, 35128, Padova, Italy. .,Department of Neurology, Washington University School of Medicine, 660S. Euclid Ave, St. Louis, MO, 63110, USA. .,Department of Radiology, Washington University School of Medicine, 660S. Euclid Ave, St. Louis, MO, 63110, USA. .,VIMM, Venetian Institute of Molecular Medicine (VIMM), Biomedical Foundation, via Orus 2, 35129, Padova, Italy.
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Gore A, Yurina A, Yukevich-Mussomeli A, Nahmani M. Synaptic spinules are reliable indicators of excitatory presynaptic bouton size and strength and are ubiquitous components of excitatory synapses in CA1 hippocampus. Front Synaptic Neurosci 2022; 14:968404. [PMID: 36032419 PMCID: PMC9403541 DOI: 10.3389/fnsyn.2022.968404] [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] [Received: 06/13/2022] [Accepted: 07/25/2022] [Indexed: 11/23/2022] Open
Abstract
Synaptic spinules are thin, finger-like projections from one neuron that become embedded within the presynaptic or postsynaptic compartments of another neuron. While spinules are conserved features of synapses across the animal kingdom, their specific function(s) remain unknown. Recent focused ion beam scanning electron microscopy (FIB-SEM) image volume analyses have demonstrated that spinules are embedded within ∼25% of excitatory boutons in primary visual cortex, yet the diversity of spinule sizes, origins, and ultrastructural relationships to their boutons remained unclear. To begin to uncover the function of synaptic spinules, we sought to determine the abundance, origins, and 3D ultrastructure of spinules within excitatory presynaptic spinule-bearing boutons (SBBs) in mammalian CA1 hippocampus and compare them with presynaptic boutons bereft of spinules (non-SBBs). Accordingly, we performed a comprehensive 3D analysis of every excitatory presynaptic bouton, their embedded spinules, and postsynaptic densities, within a 5 nm isotropic FIB-SEM image volume from CA1 hippocampus of an adult male rat. Surprisingly, we found that ∼74% of excitatory presynaptic boutons in this volume contained at least one spinule, suggesting they are fundamental components of excitatory synapses in CA1. In addition, we found that SBBs are 2.5-times larger and have 60% larger postsynaptic densities (PSDs) than non-SBBs. Moreover, synaptic spinules within SBBs are clearly differentiated into two groups: small clathrin-coated spinules, and 29-times larger spinules without clathrin. Together, these findings suggest that the presence of a spinule is a marker for stronger and more stable presynaptic boutons in CA1, and that synaptic spinules serve at least two separable and distinct functions.
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Thulborn KR. Gender differences in cell volume fraction (CVF): a structural parameter reflecting the energy efficiency of maintaining the resting membrane potential. NMR IN BIOMEDICINE 2022; 35:e4693. [PMID: 35044017 DOI: 10.1002/nbm.4693] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 01/09/2022] [Accepted: 01/10/2022] [Indexed: 06/14/2023]
Abstract
The cell volume fraction (CVF) of the human brain is high (~82%) and is preserved across healthy aging while the brain declines in volume. These two observations, supported by several independent techniques, suggest that CVF is an important structural parameter. A new biophysical model is presented that incorporates CVF into the Goldman equation of classical membrane electrophysiology. The Goldman equation contains few structural constraints beyond two compartments separated by a semipermeable membrane supporting ion gradients. As potassium is the most permeable ion in the resting state, the resting membrane potential is determined by the potassium ion gradient. This biophysical model indicates that the sodium-potassium ion pumps use less energy at high CVF to maintain the resting membrane potential, explaining the high value of CVF and its conservation with healthy aging. CVF is measured to be statistically significantly higher in the brains of males compared with females, suggesting a structural requirement for higher energy efficiency in the larger male brain to support the greater number of neurons and synapses. As CVF can be measured in humans using quantitative sodium MRI and has potential implications for brain health, CVF may be a quantitative parameter that is useful for assessment of brain health, especially in patients with diseases such as dementia and psychiatric disease that do not have anatomical correlates detectable by clinical proton MRI.
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Affiliation(s)
- Keith R Thulborn
- Center for Magnetic Resonance Research, University of Illinois at Chicago, Chicago, Illinois
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Li Q, Peng J, Luo Y, Zhou J, Li T, Cao L, Peng S, Zuo Z, Wang Z. Far infrared light irradiation enhances Aβ clearance via increased exocytotic microglial ATP and ameliorates cognitive deficit in Alzheimer's disease-like mice. J Neuroinflammation 2022; 19:145. [PMID: 35701825 PMCID: PMC9195249 DOI: 10.1186/s12974-022-02521-y] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2022] [Accepted: 06/01/2022] [Indexed: 12/12/2022] Open
Abstract
Background Exposure to sunlight may decrease the risk of developing Alzheimer’s disease (AD), and visible and near infrared light have been proposed as a possible therapeutic strategy for AD. Here, we investigated the effects of the visible, near infrared and far infrared (FIR) light on the cognitive ability of AD mice, and found that FIR light also showed potential in the improvement of cognitive dysfunction in AD. However, the related mechanism remains to be elucidated. Methods Morris water maze was used to evaluate the cognitive ability of APPswe/PSEN1dE9 double-transgenic AD mice after light treatment. Western blot was carried out to detect the expression of protein involved in synaptic function and amyloid-β (Aβ) production. The protein amount of interleukin (IL)-1β, IL-6, Aβ1-40 and Aβ1-42 were determined using enzyme-linked immunosorbent assay. The mRNA level of receptors was performed using real-time quantitative polymerase chain reaction. Immunostaining was performed to characterize the Aβ burden and microglial Aβ phagocytosis in the brain of AD mice. The Aβ phagocytosis of primary cultured microglia and BV2 were assessed by flow cytometry. The energy metabolism changes were evaluated using related assay kits, including adenosine triphosphate (ATP), lactate content, mitochondrial respiratory chain complex enzymatic activity and oxidized/reduced nicotinamide adenine dinucleotide assay kits. Results Our results showed that FIR light reduced Aβ burden, a hallmark of AD neuropathology, alleviated neuroinflammation, restored the expression of the presynaptic protein synaptophysin, and ameliorated learning and memory impairment in the AD mice. FIR light enhanced mitochondrial oxidative phosphorylation pathway to increase ATP production. This increased intracellular ATP promoted the extracellular ATP release from microglia stimulated by Aβ, leading to the enhanced Aβ phagocytosis through phosphoinositide 3-kinase/mammalian target of rapamycin pathways for Aβ clearance. Conclusions Our findings have uncovered a previously unappreciated function of FIR light in inducing microglial phagocytosis to clean Aβ, which may be the mechanisms for FIR light to improve cognitive dysfunction in AD mice. These results suggest that FIR light treatment is a potential therapeutic strategy for AD. Supplementary Information The online version contains supplementary material available at 10.1186/s12974-022-02521-y.
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Affiliation(s)
- Qingyong Li
- Department of Anesthesiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 YanJiang West Road, Guangzhou, 510289, Guangdong Province, China.,Medical Research Center, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, Guangzhou, 510120, China
| | - Jun Peng
- Department of Anesthesiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 YanJiang West Road, Guangzhou, 510289, Guangdong Province, China
| | - Yuelian Luo
- Department of Anesthesiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 YanJiang West Road, Guangzhou, 510289, Guangdong Province, China
| | - Jiaxin Zhou
- Department of Anesthesiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 YanJiang West Road, Guangzhou, 510289, Guangdong Province, China
| | - Tailin Li
- Department of Anesthesiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 YanJiang West Road, Guangzhou, 510289, Guangdong Province, China
| | - Lin Cao
- Department of Anesthesiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 YanJiang West Road, Guangzhou, 510289, Guangdong Province, China
| | - Shuling Peng
- Department of Anesthesiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 YanJiang West Road, Guangzhou, 510289, Guangdong Province, China
| | - Zhiyi Zuo
- Department of Anesthesiology, University of Virginia, Charlottesville, VA, 22901, USA. .,Department of Anesthesiology, University of Virginia Health System, 1 Hospital Drive, PO Box 800710, Charlottesville, VA, 22908-0710, USA.
| | - Zhi Wang
- Department of Anesthesiology, Sun Yat-Sen Memorial Hospital, Sun Yat-Sen University, No. 107 YanJiang West Road, Guangzhou, 510289, Guangdong Province, China.
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Cannabidiol Enhances Microglial Beta-Amyloid Peptide Phagocytosis and Clearance via Vanilloid Family Type 2 Channel Activation. Int J Mol Sci 2022; 23:ijms23105367. [PMID: 35628181 PMCID: PMC9140666 DOI: 10.3390/ijms23105367] [Citation(s) in RCA: 13] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/07/2022] [Revised: 05/05/2022] [Accepted: 05/09/2022] [Indexed: 12/23/2022] Open
Abstract
Alzheimer’s disease (AD) is associated with the accumulation and aggregation of amyloid in the brain. The cation channel TRPV2 may mediate the pathological changes in mild cognitive impairment. A high-affinity agonist of TRPV2 named cannabidiol is one of the candidate drugs for AD. However, the molecular mechanism of cannabidiol via TRPV2 in AD remains unknown. The present study investigated whether cannabidiol enhances the phagocytosis and clearance of microglial Aβ via the TRPV2 channel. We used a human dataset, mouse primary neuron and microglia cultures, and AD model mice to evaluate TRPV2 expression and the ability of microglial amyloid-β phagocytosis in vivo and in vitro. The results revealed that TRPV2 expression was reduced in the cortex and hippocampus of AD model mice and AD patients. Cannabidiol enhanced microglial amyloid-β phagocytosis through TRPV2 activation, which increased the mRNA expression of the phagocytosis-related receptors, but knockdown of TRPV2 or Trem2 rescued the expression. TRPV2-mediated effects were also dependent on PDK1/Akt signaling, a pathway in which autophagy was indispensable. Furthermore, cannabidiol treatment successfully attenuated neuroinflammation while simultaneously improving mitochondrial function and ATP production via TRPV2 activation. Therefore, TRPV2 is proposed as a potential therapeutic target in AD, while CBD is a promising drug candidate for AD.
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Deficiency of Thyroid Hormone Reduces Voltage-Gated Na + Currents as Well as Expression of Na +/K +-ATPase in the Mouse Hippocampus. Int J Mol Sci 2022; 23:ijms23084133. [PMID: 35456949 PMCID: PMC9031557 DOI: 10.3390/ijms23084133] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2022] [Revised: 03/30/2022] [Accepted: 03/30/2022] [Indexed: 02/04/2023] Open
Abstract
Mice lacking functional thyroid follicular cells, Pax8−/− mice, die early postnatally, making them suitable models for extreme hypothyroidism. We have previously obtained evidence in postnatal rat neurons, that a down-regulation of Na+-current density could explain the reduced excitability of the nervous system in hypothyroidism. If such a mechanism underlies the development of coma and death in severe hypothyroidism, Pax8−/− mice should show deficits in the expression of Na+ currents and potentially also in the expression of Na+/K+-ATPases, which are necessary to maintain low intracellular Na+ levels. We thus compared Na+ current densities in postnatal mice using the patch-clamp technique in the whole-cell configuration as well as the expression of three alpha and two beta-subunits of the Na+/K+-ATPase in wild type versus Pax8−/− mice. Whereas the Na+ current density in hippocampal neurons from wild type mice was upregulated within the first postnatal week, the Na+ current density remained at a very low level in hippocampal neurons from Pax8−/− mice. Pax8−/− mice also showed significantly decreased protein expression levels of the catalytic α1 and α3 subunits of the Na+/K+-ATPase as well as decreased levels of the β2 isoform, with no changes in the α2 and β1 subunits.
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Abstract
The brain is a highly energy-demanding organ and requires bioenergetic adaptability to balance normal activity with pathophysiological fuelling of spontaneous recurrent seizures, the hallmark feature of the epilepsies. Recurrent or prolonged seizures have long been known to permanently alter neuronal circuitry and to cause excitotoxic injury and aberrant inflammation. Furthermore, pathological changes in bioenergetics and metabolism are considered downstream consequences of epileptic seizures that begin at the synaptic level. However, as we highlight in this Review, evidence is also emerging that primary derangements in cellular or mitochondrial metabolism can result in seizure genesis and lead to spontaneous recurrent seizures. Basic and translational research indicates that the relationships between brain metabolism and epileptic seizures are complex and bidirectional, producing a vicious cycle that compounds the deleterious consequences of seizures. Metabolism-based treatments such as the high-fat, antiseizure ketogenic diet have become mainstream, and metabolic substrates and enzymes have become attractive molecular targets for seizure prevention and recovery. Moreover, given that metabolism is crucial for epigenetic as well as inflammatory changes, the idea that epileptogenesis can be both negatively and positively influenced by metabolic changes is rapidly gaining ground. Here, we review evidence that supports both pathophysiological and therapeutic roles for brain metabolism in epilepsy.
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