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Ye YC, Chai SF, Li XR, Wu MN, Cai HY, Wang ZJ. Intermittent fasting and Alzheimer's disease-Targeting ketone bodies as a potential strategy for brain energy rescue. Metab Brain Dis 2024; 39:129-146. [PMID: 37823968 DOI: 10.1007/s11011-023-01288-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/15/2023] [Accepted: 09/01/2023] [Indexed: 10/13/2023]
Abstract
Alzheimer's disease (AD) lacks effective clinical treatments. As the disease progresses, the cerebral glucose hypometabolism that appears in the preclinical phase of AD gradually worsens, leading to increasingly severe brain energy disorders. This review analyzes the brain energy deficit in AD and its etiology, brain energy rescue strategies based on ketone intervention, the effects and mechanisms of IF, the differences in efficacy between IF and ketogenic diet and the duality of IF. The evidence suggests that brain energy deficits lead to the development and progression of AD pathology. IF, which improves brain energy impairments by promoting ketone metabolism, thus has good therapeutic potential for AD.
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Affiliation(s)
- Yu- Cai Ye
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Shi-Fan Chai
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Xin-Ru Li
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Mei-Na Wu
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Hong-Yan Cai
- Department of Microbiology and Immunology, Shanxi Medical University, Taiyuan, People's Republic of China
| | - Zhao-Jun Wang
- Department of Physiology, Key Laboratory of Cellular Physiology, Ministry of Education, Shanxi Medical University, Taiyuan, People's Republic of China.
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Caiola HO, Wu Q, Soni S, Wang XF, Monahan K, Pang ZP, Wagner GC, Zhang H. Neuronal connectivity, behavioral, and transcriptional alterations associated with the loss of MARK2. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2023:2023.12.05.569759. [PMID: 38105965 PMCID: PMC10723285 DOI: 10.1101/2023.12.05.569759] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/19/2023]
Abstract
Neuronal connectivity is essential for adaptive brain responses and can be modulated by dendritic spine plasticity and the intrinsic excitability of individual neurons. Dysregulation of these processes can lead to aberrant neuronal activity, which has been associated with numerous neurological disorders including autism, epilepsy, and Alzheimer's disease. Nonetheless, the molecular mechanisms underlying aberrant neuronal connectivity remains unclear. We previously found that the serine/threonine kinase Microtubule Affinity Regulating Kinase 2 (MARK2), also known as Partitioning Defective 1b (Par1b), is important for the formation of dendritic spines in vitro. However, despite its genetic association with several neurological disorders, the in vivo impact of MARK2 on neuronal connectivity and cognitive functions remains unclear. Here, we demonstrate that loss of MARK2 in vivo results in changes to dendritic spine morphology, which in turn leads to a decrease in excitatory synaptic transmission. Additionally, loss of MARK2 produces substantial impairments in learning and memory, anxiety, and social behavior. Notably, MARK2 deficiency results in heightened seizure susceptibility. Consistent with this observation, RNAseq analysis reveals transcriptional changes in genes regulating synaptic transmission and ion homeostasis. These findings underscore the in vivo role of MARK2 in governing synaptic connectivity, cognitive functions, and seizure susceptibility.
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Vande Vyver M, Daeninck L, De Smet G, Aourz N, Sahu S, Engelborghs S, Pauwels K, De Bundel D, Smolders I. The intracerebral injection of Aβ 1-42 oligomers does not invariably alter seizure susceptibility in mice. Front Aging Neurosci 2023; 15:1239140. [PMID: 37744393 PMCID: PMC10512828 DOI: 10.3389/fnagi.2023.1239140] [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: 06/12/2023] [Accepted: 08/22/2023] [Indexed: 09/26/2023] Open
Abstract
Objectives Epileptiform activity and seizures are present in patients with Alzheimer's disease (AD) and genetic animal models of AD. Amyloid beta 1-42 (Aβ1-42) oligomers are thought to be crucial in AD and can cause neuronal hyperexcitability in vitro. However, it is unclear whether these Aβ1-42 oligomers cause the increased seizure susceptibility in vivo in people with AD and in AD animal models, nor via which mechanisms it would do so. We investigated this question by injecting Aβ1-42 oligomers intracerebrally in mice and assessed its impact on seizure susceptibility. Materials and methods We performed a single intracerebral injection of synthetic Aβ1-42 oligomers or scrambled Aβ1-42 in NMRI mice in three different cohorts and subjected them to an i.v. infusion of a chemoconvulsant. We evoked the seizures 1.5 h, 1 week, or 3 weeks after the intracerebral injection of Aβ1-42 oligomers, covering also the timepoints and injection locations that were used by others in similar experimental set-ups. Results With a thioflavine T assay and transmission electron microscopy we confirmed that Aβ1-42 monomers spontaneously aggregated to oligomers. We did not find an effect of Aβ1-42 oligomers on susceptibility to seizures - evoked 1.5 h, 1 week or 3 weeks - after their intracerebral injection. Significance The lack of effect of Aβ1-42 oligomers on seizure susceptibility in our experiments contrasts with recent findings in similar experimental set-ups. Contradicting conclusions are frequent in experiments with Aβ1-42 and they are often attributed to subtle differences in the various aggregation forms of the Aβ1-42 used in different experiments. We confirmed the presence of Aβ1-42 oligomers with state-of-the-art methods but cannot ascertain that the protein aggregates we used are identical to those used by others. Whether our findings or those previously published best represent the role of Aβ1-42 oligomers on seizures in AD remains unclear.
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Affiliation(s)
- Maxime Vande Vyver
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
- Department of Neurology and Bru-BRAIN, Universitair Ziekenhuis Brussel, Brussels, Belgium
- NEUR Research Group, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
- Department of Biomedical Sciences, Reference Center for Biological Markers of Dementia (BIODEM), University of Antwerp, Antwerp, Belgium
| | - Louise Daeninck
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
| | - Gino De Smet
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
| | - Najat Aourz
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
| | - Surajit Sahu
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
| | - Sebastiaan Engelborghs
- Department of Neurology and Bru-BRAIN, Universitair Ziekenhuis Brussel, Brussels, Belgium
- NEUR Research Group, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
- Department of Biomedical Sciences, Reference Center for Biological Markers of Dementia (BIODEM), University of Antwerp, Antwerp, Belgium
| | - Kris Pauwels
- RESEARCH Department, Vrije Universiteit Brussel, Brussels, Belgium
| | - Dimitri De Bundel
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
| | - Ilse Smolders
- Department of Pharmaceutical Chemistry, Drug Analysis and Drug Information, Research Group Experimental Pharmacology (EFAR), Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
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Escobar I, Xu J, Jackson CW, Stegelmann SD, Fagerli EA, Dave KR, Perez-Pinzon MA. Resveratrol Preconditioning Protects Against Ischemia-Induced Synaptic Dysfunction and Cofilin Hyperactivation in the Mouse Hippocampal Slice. Neurotherapeutics 2023; 20:1177-1197. [PMID: 37208551 PMCID: PMC10457274 DOI: 10.1007/s13311-023-01386-0] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 04/23/2023] [Indexed: 05/21/2023] Open
Abstract
Perturbations in synaptic function are major determinants of several neurological diseases and have been associated with cognitive impairments after cerebral ischemia (CI). Although the mechanisms underlying CI-induced synaptic dysfunction have not been well defined, evidence suggests that early hyperactivation of the actin-binding protein, cofilin, plays a role. Given that synaptic impairments manifest shortly after CI, prophylactic strategies may offer a better approach to prevent/mitigate synaptic damage following an ischemic event. Our laboratory has previously demonstrated that resveratrol preconditioning (RPC) promotes cerebral ischemic tolerance, with many groups highlighting beneficial effects of resveratrol treatment on synaptic and cognitive function in other neurological conditions. Herein, we hypothesized that RPC would mitigate hippocampal synaptic dysfunction and pathological cofilin hyperactivation in an ex vivo model of ischemia. Various electrophysiological parameters and synaptic-related protein expression changes were measured under normal and ischemic conditions utilizing acute hippocampal slices derived from adult male mice treated with resveratrol (10 mg/kg) or vehicle 48 h prior. Remarkably, RPC significantly increased the latency to anoxic depolarization, decreased cytosolic calcium accumulation, prevented aberrant increases in synaptic transmission, and rescued deficits in long-term potentiation following ischemia. Additionally, RPC upregulated the expression of the activity-regulated cytoskeleton associated protein, Arc, which was partially required for RPC-mediated attenuation of cofilin hyperactivation. Taken together, these findings support a role for RPC in mitigating CI-induced excitotoxicity, synaptic dysfunction, and pathological over-activation of cofilin. Our study provides further insight into mechanisms underlying RPC-mediated neuroprotection against CI and implicates RPC as a promising strategy to preserve synaptic function after ischemia.
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Affiliation(s)
- Iris Escobar
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Jing Xu
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Charles W Jackson
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Samuel D Stegelmann
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Eric A Fagerli
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Kunjan R Dave
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA
| | - Miguel A Perez-Pinzon
- Peritz Scheinberg Cerebral Vascular Disease Research Laboratories, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA.
- Department of Neurology, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA.
- Neuroscience Program, University of Miami Leonard M. Miller School of Medicine, PO Box 016960, Miami, FL, 33101, USA.
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Scaduto P, Lauterborn JC, Cox CD, Fracassi A, Zeppillo T, Gutierrez BA, Keene CD, Crane PK, Mukherjee S, Russell WK, Taglialatela G, Limon A. Functional excitatory to inhibitory synaptic imbalance and loss of cognitive performance in people with Alzheimer's disease neuropathologic change. Acta Neuropathol 2023; 145:303-324. [PMID: 36538112 PMCID: PMC9925531 DOI: 10.1007/s00401-022-02526-0] [Citation(s) in RCA: 14] [Impact Index Per Article: 14.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/25/2022] [Revised: 11/12/2022] [Accepted: 11/27/2022] [Indexed: 12/24/2022]
Abstract
Individuals at distinct stages of Alzheimer's disease (AD) show abnormal electroencephalographic activity, which has been linked to network hyperexcitability and cognitive decline. However, whether pro-excitatory changes at the synaptic level are observed in brain areas affected early in AD, and if they are emergent in MCI, is not clearly known. Equally important, it is not known whether global synaptic E/I imbalances correlate with the severity of cognitive impairment in the continuum of AD. Measuring the amplitude of ion currents of human excitatory and inhibitory synaptic receptors microtransplanted from the hippocampus and temporal cortex of cognitively normal, mildly cognitively impaired and AD individuals into surrogate cells, we found regional differences in pro-excitatory shifts of the excitatory to inhibitory (E/I) current ratio that correlates positively with toxic proteins and degree of pathology, and impinges negatively on cognitive performance scores. Using these data with electrophysiologically anchored analysis of the synapto-proteome in the same individuals, we identified a group of proteins sustaining synaptic function and those related to synaptic toxicity. We also found an uncoupling between the function and expression of proteins for GABAergic signaling in the temporal cortex underlying larger E/I and worse cognitive performance. Further analysis of transcriptomic and in situ hybridization datasets from an independent cohort across the continuum of AD confirm regional differences in pro-excitatory shifts of the E/I balance that correlate negatively with the most recent calibrated composite scores for memory, executive function, language and visuospatial abilities, as well as overall cognitive performance. These findings indicate that early shifts of E/I balance may contribute to loss of cognitive capabilities in the continuum of AD clinical syndrome.
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Affiliation(s)
- Pietro Scaduto
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Julie C Lauterborn
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, CA, USA
| | - Conor D Cox
- Department of Anatomy and Neurobiology, University of California Irvine, Irvine, CA, USA
| | - Anna Fracassi
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Tommaso Zeppillo
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Berenice A Gutierrez
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - C Dirk Keene
- Department of Laboratory Medicine and Pathology, University of Washington School of Medicine, Seattle, WA, USA
| | - Paul K Crane
- Department of Medicine, University of Washington, Seattle, WA, USA
| | | | - William K Russell
- Department of Biochemistry and Molecular Biology, University of Texas Medical Branch at Galveston, Galveston, USA
| | - Giulio Taglialatela
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston, Galveston, TX, USA
| | - Agenor Limon
- Department of Neurology, Mitchell Center for Neurodegenerative Diseases, University of Texas Medical Branch at Galveston, Galveston, TX, USA.
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Merlo S, Costa L, Chiechio S, Busceti CL, Ciranna L, Santangelo R, Sortino MA, Fornai F, Nicoletti F, Copani A. Increased Heat Pain Tolerance but Hyperalgesia to Tonic Inflammatory Pain in the CRND8 Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2023; 96:77-91. [PMID: 37742639 PMCID: PMC10657672 DOI: 10.3233/jad-230148] [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] [Accepted: 08/08/2023] [Indexed: 09/26/2023]
Abstract
BACKGROUND The effects of Alzheimer's disease (AD) pathology on the experience of pain are poorly understood. OBJECTIVE To understand the pathophysiological mechanisms underlying pain sensory transmission in the transgenic mouse model of AD, CRND8. METHODS We explored AD-related pathology in the spinal cord and dorsal root ganglia of 18-week-old female CRND8 mice. We assessed nociceptive responses to both acute heat stimuli and persistent inflammatory pain in CRND8 mice and non-transgenic (non-Tg) littermates. In addition, we searched for differences in biochemical correlates of inflammatory pain between CRND8 and non-Tg mice. Finally, we investigated the excitability of dorsal horn noc iceptive neurons in spinal cord slices from CRND8 and non-Tg mice. RESULTS We demonstrated the presence of intracellular AD-like pathology in the spinal cord and in the dorsal root ganglia nociceptive sensory neurons of CRND8 mice. We found that CRND8 mice had a reduced susceptibility to acute noxious heat stimuli and an increased sensitivity to tonic inflammatory pain. Tonic inflammatory pain correlated with a lack of induction of pro-opiomelanocortin in the spinal cord of CRND8 mice as compared to non-Tg mice. Electrophysiological recording in acute spinal cord slice preparations indicated an increased probability of glutamate release at the membrane of dorsal horn nociceptive neurons in CRND8 mice. CONCLUSION This study suggests that an increased thermal tolerance and a facilitation of nociception by peripheral inflammation can coexist in AD.
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Affiliation(s)
- Sara Merlo
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Lara Costa
- Department of Clinical and Experimental Medicine, University of Messina, Messina, Italy
| | - Santina Chiechio
- Department of Drug and Health Sciences, University of Catania, Catania, Italy
- Oasi Research Institute - IRCCS, Troina, Italy
| | | | - Lucia Ciranna
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Rosa Santangelo
- Department of Drug and Health Sciences, University of Catania, Catania, Italy
| | - Maria Angela Sortino
- Department of Biomedical and Biotechnological Sciences, University of Catania, Catania, Italy
| | - Francesco Fornai
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli, Italy
- Department of Translational Research and New Technologies in Medicine and Surgery, University of Pisa, Pisa, Italy
| | - Ferdinando Nicoletti
- Department of Molecular Pathology, IRCCS Neuromed, Pozzilli, Italy
- Department of Physiology and Pharmacology, University Sapienza, Rome, Italy
| | - Agata Copani
- Department of Drug and Health Sciences, University of Catania, Catania, Italy
- Institute of Crystallography, National Council of Research, Catania Unit, Catania, Italy
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Yavorsky VA, Rozumna NM, Lukyanetz EA. Influence of amyloid beta on impulse spiking of isolated hippocampal neurons. Front Cell Neurosci 2023; 17:1132092. [PMID: 37124394 PMCID: PMC10133472 DOI: 10.3389/fncel.2023.1132092] [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: 12/26/2022] [Accepted: 03/29/2023] [Indexed: 05/02/2023] Open
Abstract
One of the signs of Alzheimer's disease (AD) is the formation of β-amyloid plaques, which ultimately lead to the dysfunction of neurons with subsequent neurodegeneration. Although extensive researches have been conducted on the effects of different amyloid conformations such as oligomers and fibrils on neuronal function in isolated cells and circuits, the exact contribution of extracellular beta-amyloid on neurons remains incompletely comprehended. In our experiments, we studied the effect of β-amyloid peptide (Aβ1-42) on the action potential (APs) generation in isolated CA1 hippocampal neurons in perforated patch clamp conditions. Our findings demonstrate that Aβ1-42 affects the generation of APs differently in various hippocampal neurons, albeit with a shared effect of enhancing the firing response of the neurons within a minute of the start of Aβ1-42 application. In the first response type, there was a shift of 20-65% toward smaller values in the firing threshold of action potentials in response to inward current. Conversely, the firing threshold of action potentials was not affected in the second type of response to the application of Aβ1-42. In these neurons, Aβ1-42 caused a moderate increase in the frequency of spiking, up to 15%, with a relatively uniform increase in the frequency of action potentials generation regardless of the level of input current. Obtained data prove the absence of direct short-term negative effect of the Aβ1-42 on APs generation in neurons. Even with increasing the APs generation frequency and lowering the neurons' activation threshold, neurons were functional. Obtained data can suggest that only the long-acting presence of the Aβ1-42 in the cell environment can cause neuronal dysfunction due to a prolonged increase of APs firing and predisposition to this process.
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Samudra N, Ranasinghe K, Kirsch H, Rankin K, Miller B. Etiology and Clinical Significance of Network Hyperexcitability in Alzheimer's Disease: Unanswered Questions and Next Steps. J Alzheimers Dis 2023; 92:13-27. [PMID: 36710680 DOI: 10.3233/jad-220983] [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] [Indexed: 01/25/2023]
Abstract
Cortical network hyperexcitability related to synaptic dysfunction in Alzheimer's disease (AD) is a potential target for therapeutic intervention. In recent years, there has been increased interest in the prevalence of silent seizures and interictal epileptiform discharges (IEDs, or seizure tendency), with both entities collectively termed "subclinical epileptiform activity" (SEA), on neurophysiologic studies in AD patients. SEA has been demonstrated to be common in AD, with prevalence estimates ranging between 22-54%. Converging lines of basic and clinical evidence imply that modifying a hyperexcitable state results in an improvement in cognition. In particular, though these results require further confirmation, post-hoc findings from a recent phase II clinical trial suggest a therapeutic effect with levetiracetam administration in patients with AD and IEDs. Here, we review key unanswered questions as well as potential clinical trial avenues. Specifically, we discuss postulated mechanisms and treatment of hyperexcitability in patients with AD, which are of interest in designing future disease-modifying therapies. Criteria to prompt screening and optimal screening methodology for hyperexcitability have yet to be defined, as does timing and personalization of therapeutic intervention.
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Affiliation(s)
- Niyatee Samudra
- Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA
| | - Kamalini Ranasinghe
- Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA
| | - Heidi Kirsch
- University of California, San Francisco Comprehensive Epilepsy Center, San Francisco, CA, USA
| | - Katherine Rankin
- Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA
| | - Bruce Miller
- Memory and Aging Center, University of California, San Francisco, San Francisco, CA, USA
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Lu W, Tang S, Li A, Huang Q, Dou M, Zhang Y, Hu X, Chang RCC, Wong GTC, Huang C. The role of PKC/PKR in aging, Alzheimer's disease, and perioperative neurocognitive disorders. Front Aging Neurosci 2022; 14:973068. [PMID: 36172481 PMCID: PMC9510619 DOI: 10.3389/fnagi.2022.973068] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2022] [Accepted: 08/16/2022] [Indexed: 11/16/2022] Open
Abstract
Background The incidence of perioperative neurocognitive disorders (PNDs) is reportedly higher in older patients. Mitochondrial and synaptic dysfunctions have consistently been demonstrated in models of aging and neurodegenerative diseases; nonetheless, their role in PND is not well understood. Methods The Morris water maze and elevated plus maze tests were used to assess the learning and memory abilities of both C57BL/6 and 3×Tg-AD mice of different ages (8 and 18 months). PND was induced by laparotomy in C57BL/6 mice and 3×Tg-AD mice (8 months old). Markers associated with neuroinflammation, mitochondrial function, synaptic function, and autophagy were assessed postoperatively. The roles of protein kinase C (PKC) and double-stranded RNA-dependent protein kinase (PKR) were further demonstrated by using PKC-sensitive inhibitor bisindolylmaleimide X (BIMX) or PKR−/− mice. Results Significant cognitive impairment was accompanied by mitochondrial dysfunction and autophagy inactivation in both aged C57BL/6 and 3×Tg-AD mice. Laparotomy induced a significant neuroinflammatory response and synaptic protein loss in the hippocampus. Cognitive and neuropathological changes induced by aging or laparotomy were further exacerbated in 3×Tg-AD mice. Deficits in postoperative cognition, hippocampal mitochondria, autophagy, and synapse were significantly attenuated after pharmacological inhibition of PKC or genetic deletion of PKR. Conclusions Our findings suggest similar pathogenic features in aging, Alzheimer's disease, and PND, including altered mitochondrial homeostasis and autophagy dysregulation. In addition, laparotomy may exacerbate cognitive deficits associated with distinct neuronal inflammation, mitochondrial dysfunction, and neuronal loss independent of genetic background. The dysregulation of PKC/PKR activity may participate in the pathogenesis of these neurodegenerative diseases.
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Affiliation(s)
- Wenping Lu
- Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
- Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
- Scientific Research and Experiment Center of the Second Affilliated Hospital of Anhui Medical University, Hefei, China
| | - Sailan Tang
- Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
- Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
- Scientific Research and Experiment Center of the Second Affilliated Hospital of Anhui Medical University, Hefei, China
| | - Ao Li
- The Second Clinical Medical College of Anhui Medical University, Hefei, China
| | - Qiuyue Huang
- The Second Clinical Medical College of Anhui Medical University, Hefei, China
| | - Mengyun Dou
- Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
| | - Ye Zhang
- Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
- Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Xianwen Hu
- Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
- Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
| | - Raymond Chuen Chung Chang
- Laboratory of Neurodegenerative Diseases, School of Biomedical Sciences, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- State Key Laboratory of Brain and Cognitive Sciences, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
| | - Gordon Tin Chun Wong
- Department of Anaesthesiology, LKS Faculty of Medicine, The University of Hong Kong, Pokfulam, Hong Kong SAR, China
- *Correspondence: Gordon Tin Chun Wong
| | - Chunxia Huang
- Department of Anesthesiology, The Second Affiliated Hospital of Anhui Medical University, Hefei, China
- Key Laboratory of Anesthesiology and Perioperative Medicine of Anhui Higher Education Institutes, Anhui Medical University, Hefei, China
- Chunxia Huang
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Anti-Inflammatory Activity of 4-(4-(Heptyloxy)phenyl)-2,4-dihydro-3 H-1,2,4-triazol-3-one via Repression of MAPK/NF-κB Signaling Pathways in β-Amyloid-Induced Alzheimer's Disease Models. MOLECULES (BASEL, SWITZERLAND) 2022; 27:molecules27155035. [PMID: 35956985 PMCID: PMC9370156 DOI: 10.3390/molecules27155035] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/07/2022] [Revised: 07/31/2022] [Accepted: 08/05/2022] [Indexed: 01/03/2023]
Abstract
Alzheimer’s disease (AD) is a major neurodegenerative disease, but so far, it can only be treated symptomatically rather than changing the process of the disease. Recently, triazoles and their derivatives have been shown to have potential for the treatment of AD. In this study, the neuroprotective effects of 4-(4-(heptyloxy)phenyl)-2,4-dihydro-3H-1,2,4-triazol-3-one (W112) against β-amyloid (Aβ)-induced AD pathology and its possible mechanism were explored both in vitro and in vivo. The results showed that W112 exhibits a neuroprotective role against Aβ-induced cytotoxicity in PC12 cells and improves the learning and memory abilities of Aβ-induced AD-like rats. In addition, the assays of the protein expression revealed that W112 reversed tau hyperphosphorylation and reduced the production of proinflammatory cytokines, tumor necrosis factor-α and interleukin-6, both in vitro and in vivo studies. Further study indicated that the regulation of mitogen-activated protein kinase/nuclear factor-κB pathways played a key role in mediating the neuroprotective effects of W112 against AD-like pathology. W112 may become a potential drug for AD intervention.
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Zhang D, Chen S, Xu S, Wu J, Zhuang Y, Cao W, Chen X, Li X. The clinical correlation between Alzheimer's disease and epilepsy. Front Neurol 2022; 13:922535. [PMID: 35937069 PMCID: PMC9352925 DOI: 10.3389/fneur.2022.922535] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2022] [Accepted: 06/30/2022] [Indexed: 11/17/2022] Open
Abstract
Alzheimer's disease and epilepsy are common nervous system diseases in older adults, and their incidence rates tend to increase with age. Patients with mild cognitive impairment and Alzheimer's disease are more prone to have seizures. In patients older than 65 years, neurodegenerative conditions accounted for ~10% of all late-onset epilepsy cases, most of which are Alzheimer's disease. Epilepsy and seizure can occur in the early and late stages of Alzheimer's disease, leading to functional deterioration and behavioral alterations. Seizures promote amyloid-β and tau deposits, leading to neurodegenerative processes. Thus, there is a bi-directional association between Alzheimer's disease and epilepsy. Epilepsy is a risk factor for Alzheimer's disease and, in turn, Alzheimer's disease is an independent risk factor for developing epilepsy in old age. Many studies have evaluated the shared pathogenesis and clinical relevance of Alzheimer's disease and epilepsy. In this review, we discuss the clinical associations between Alzheimer's disease and epilepsy, including their incidence, clinical features, and electroencephalogram abnormalities. Clinical studies of the two disorders in recent years are summarized, and new antiepileptic drugs used for treating Alzheimer's disease are reviewed.
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Ramirez AE, Fernández-Pérez EJ, Olivos N, Burgos CF, Boopathi S, Armijo-Weingart L, Pacheco CR, González W, Aguayo LG. The Stimulatory Effects of Intracellular α-Synuclein on Synaptic Transmission Are Attenuated by 2-Octahydroisoquinolin-2(1H)-ylethanamine. Int J Mol Sci 2021; 22:ijms222413253. [PMID: 34948050 PMCID: PMC8705949 DOI: 10.3390/ijms222413253] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/23/2021] [Accepted: 11/25/2021] [Indexed: 11/16/2022] Open
Abstract
α-Synuclein (αSyn) species can be detected in synaptic boutons, where they play a crucial role in the pathogenesis of Parkinson's Disease (PD). However, the effects of intracellular αSyn species on synaptic transmission have not been thoroughly studied. Here, using patch-clamp recordings in hippocampal neurons, we report that αSyn oligomers (αSynO), intracellularly delivered through the patch electrode, produced a fast and potent effect on synaptic transmission, causing a substantial increase in the frequency, amplitude and transferred charge of spontaneous synaptic currents. We also found an increase in the frequency of miniature synaptic currents, suggesting an effect located at the presynaptic site of the synapsis. Furthermore, our in silico approximation using docking analysis and molecular dynamics simulations showed an interaction between a previously described small anti-amyloid beta (Aβ) molecule, termed M30 (2-octahydroisoquinolin-2(1H)-ylethanamine), with a central hydrophobic region of αSyn. In line with this finding, our empirical data aimed to obtain oligomerization states with thioflavin T (ThT) and Western blot (WB) indicated that M30 interfered with αSyn aggregation and decreased the formation of higher-molecular-weight species. Furthermore, the effect of αSynO on synaptic physiology was also antagonized by M30, resulting in a decrease in the frequency, amplitude, and charge transferred of synaptic currents. Overall, the present results show an excitatory effect of intracellular αSyn low molecular-weight species, not previously described, that are able to affect synaptic transmission, and the potential of a small neuroactive molecule to interfere with the aggregation process and the synaptic effect of αSyn, suggesting that M30 could be a potential therapeutic strategy for synucleinopathies.
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Affiliation(s)
- Alejandra E. Ramirez
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Eduardo J. Fernández-Pérez
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
- Correspondence: (E.J.F.-P.); (L.G.A.)
| | - Nicol Olivos
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Carlos F. Burgos
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Subramanian Boopathi
- Instituto de Ciencias Físicas, Universidad Nacional Autónoma de México, Cuernavaca 62210, Mexico;
- Center for Bioinformatics, Simulations and Modeling, The Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3530000, Chile;
| | - Lorena Armijo-Weingart
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Carla R. Pacheco
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
| | - Wendy González
- Center for Bioinformatics, Simulations and Modeling, The Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3530000, Chile;
- Millennium Nucleus of Ion Channels-Associated Diseases, The Center for Bioinformatics and Molecular Simulations (CBSM), University of Talca, Talca 3530000, Chile
| | - Luis G. Aguayo
- Laboratory of Neurophysiology, Department of Physiology, Faculty of Biological Sciences, Universidad de Concepción, 160-C, Concepción 4030000, Chile; (A.E.R.); (N.O.); (C.F.B.); (L.A.-W.); (C.R.P.)
- Programa de Neurociencia, Psiquiatría y Salud Mental, Anatomy Building,
Faculty of Medicine, Universidad de Concepción, Concepción 4030000, Chile
- Correspondence: (E.J.F.-P.); (L.G.A.)
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Fernandez‐Perez EJ, Muñoz B, Bascuñan DA, Peters C, Riffo‐Lepe NO, Espinoza MP, Morgan PJ, Filippi C, Bourboulou R, Sengupta U, Kayed R, Epsztein J, Aguayo LG. Synaptic dysregulation and hyperexcitability induced by intracellular amyloid beta oligomers. Aging Cell 2021; 20:e13455. [PMID: 34409748 PMCID: PMC8441418 DOI: 10.1111/acel.13455] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/23/2021] [Revised: 07/21/2021] [Accepted: 08/05/2021] [Indexed: 12/19/2022] Open
Abstract
Intracellular amyloid beta oligomer (iAβo) accumulation and neuronal hyperexcitability are two crucial events at early stages of Alzheimer's disease (AD). However, to date, no mechanism linking iAβo with an increase in neuronal excitability has been reported. Here, the effects of human AD brain-derived (h-iAβo) and synthetic (iAβo) peptides on synaptic currents and action potential firing were investigated in hippocampal neurons. Starting from 500 pM, iAβo rapidly increased the frequency of synaptic currents and higher concentrations potentiated the AMPA receptor-mediated current. Both effects were PKC-dependent. Parallel recordings of synaptic currents and nitric oxide (NO)-associated fluorescence showed that the increased frequency, related to pre-synaptic release, was dependent on a NO-mediated retrograde signaling. Moreover, increased synchronization in NO production was also observed in neurons neighboring those dialyzed with iAβo, indicating that iAβo can increase network excitability at a distance. Current-clamp recordings suggested that iAβo increased neuronal excitability via AMPA-driven synaptic activity without altering membrane intrinsic properties. These results strongly indicate that iAβo causes functional spreading of hyperexcitability through a synaptic-driven mechanism and offers an important neuropathological significance to intracellular species in the initial stages of AD, which include brain hyperexcitability and seizures.
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Affiliation(s)
| | - Braulio Muñoz
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Denisse A. Bascuñan
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Christian Peters
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Nicolas O. Riffo‐Lepe
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Maria P. Espinoza
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
| | - Peter J. Morgan
- Institute of Neurobiology of the Mediterranean Sea (INMED)Institut National de la Santé et de la Recherche Médicale (INSERM) U901, Aix-Marseille UniversitéMarseilleFrance
| | - Caroline Filippi
- Institute of Neurobiology of the Mediterranean Sea (INMED)Institut National de la Santé et de la Recherche Médicale (INSERM) U901, Aix-Marseille UniversitéMarseilleFrance
| | - Romain Bourboulou
- Institute of Neurobiology of the Mediterranean Sea (INMED)Institut National de la Santé et de la Recherche Médicale (INSERM) U901, Aix-Marseille UniversitéMarseilleFrance
| | - Urmi Sengupta
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTexasUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTexasUSA
| | - Rakez Kayed
- Mitchell Center for Neurodegenerative DiseasesUniversity of Texas Medical BranchGalvestonTexasUSA
- Department of Neurology, Neuroscience and Cell BiologyUniversity of Texas Medical BranchGalvestonTexasUSA
| | - Jérôme Epsztein
- Institute of Neurobiology of the Mediterranean Sea (INMED)Institut National de la Santé et de la Recherche Médicale (INSERM) U901, Aix-Marseille UniversitéMarseilleFrance
| | - Luis G. Aguayo
- Laboratory of NeurophysiologyDepartment of PhysiologyUniversidad de ConcepciónConcepciónChile
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