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Reddy AP, Rawat P, Rohr N, Alvir R, Bisht J, Bushra MA, Luong J, Reddy AP. Role of Serotonylation and SERT Posttranslational Modifications in Alzheimer's Disease Pathogenesis. Aging Dis 2024:AD.2024.0328. [PMID: 38607731 DOI: 10.14336/ad.2024.0328] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/03/2024] [Accepted: 03/28/2024] [Indexed: 04/14/2024] Open
Abstract
The neurotransmitter serotonin (5-hydroxytryptamine, 5-HT) is implicated mainly in Alzheimer's disease (AD) and reported to be responsible for several processes and roles in the human body, such as regulating sleep, food intake, sexual behavior, anxiety, and drug abuse. It is synthesized from the amino acid tryptophan. Serotonin also functions as a signal between neurons to mature, survive, and differentiate. It plays a crucial role in neuronal plasticity, including cell migration and cell contact formation. Various psychiatric disorders, such as depression, schizophrenia, autism, and Alzheimer's disease, have been linked to an increase in serotonin-dependent signaling during the development of the nervous system. Recent studies have found 5-HT and other monoamines embedded in the nuclei of various cells, including immune cells, the peritoneal mast, and the adrenal medulla. Evidence suggests these monoamines to be involved in widespread intracellular regulation by posttranslational modifications (PTMs) of proteins. Serotonylation is the calcium-dependent process in which 5-HT forms a long-lasting covalent bond to small cytoplasmic G-proteins by endogenous transglutaminase 2 (TGM2). Serotonylation plays a role in various biological processes. The purpose of our article is to summarize historical developments and recent advances in serotonin research and serotonylation in depression, aging, AD, and other age-related neurological diseases. We also discussed several of the latest developments with Serotonin, including biological functions, pathophysiological implications and therapeutic strategies to treat patients with depression, dementia, and other age-related conditions.
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Zhang C, Tian F, Peng J, Wang X, Li J, Zhang L, Tan Z. Serotonergic neurotransmission mediated cognitive dysfunction in two mouse models of sepsis-associated encephalopathy. CNS Neurosci Ther 2024; 30:e14655. [PMID: 38433019 PMCID: PMC10909618 DOI: 10.1111/cns.14655] [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: 12/19/2023] [Revised: 02/12/2024] [Accepted: 02/13/2024] [Indexed: 03/05/2024] Open
Abstract
BACKGROUND Patients with sepsis-associated encephalopathy (SAE) often exhibit cognitive impairments. Despite this, the underlying mechanisms of SAE remain largely unexplored. Here, we explored the role of serotonergic neurotransmission in cognitive dysfunction of two mouse models of SAE. METHODS The mouse models of SAE were established by injection of lipopolysaccharide (LPS, 10 mg/kg, intraperitoneal) and cecal ligation puncture (CLP) respectively. Barnes maze, new object recognition test and open field test were used to evaluate the effects of fluoxetine (selective serotonin reuptake inhibitor) and cyproheptadine (nonselective 5-HT2 receptor antagonist) on cognition and motor activity of mice. Additionally, WAY100635 (5-HT1A receptor antagonist) was co-administered with fluoxetine to explore the mechanism underlying effect of fluoxetine on cognitive impairments of SAE. Enzyme-linked immunosorbent assay (ELISA) was performed to determine 5-HT levels in hippocampus, brainstem and frontal lobe of experimental groups. RESULTS Both LPS-induced sepsis and CLP induced sepsis resulted in a notable learning deficit. Fluoxetine ameliorated, while cyproheptadine aggravated, cognitive impairment in two classic mouse models of SAE. The cognition-enhancing effect of fluoxetine is reversed by WAY100635. Decreased 5-HT levels in hippocampus, brainstem and frontal lobe were observed in LPS septic model and CLP septic model. Notably, both fluoxetine and cyproheptadine significantly increased 5-HT levels in those brain regions in LPS septic model. Additionally, fluoxetine significantly increased 5-HT levels in frontal lobe of CLP septic model. CONCLUSIONS Our study demonstrated that serotonergic neurotransmission plays a significant role in mechanisms underlying cognitive impairment in SAE. These findings contribute to identification of novel targets to prevent and arrest cognitive impairment in SAE.
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Affiliation(s)
- Chen Zhang
- Department of Pediatrics, Xiangya HospitalCentral South UniversityChangshaChina
| | - Fafa Tian
- Department of Neurology, Xiangya HospitalCentral South UniversityChangshaChina
| | - Jing Peng
- Department of Pediatrics, Xiangya HospitalCentral South UniversityChangshaChina
| | - Xia Wang
- Department of Pediatrics, Xiangya HospitalCentral South UniversityChangshaChina
| | - Jingchen Li
- Department of Neurology, Xiangya HospitalCentral South UniversityChangshaChina
- Bioinformatics Center & National Clinical Research Centre for Geriatric Disorders & Department of Geriatrics, Xiangya HospitalCentral South UniversityChangshaHumanChina
| | - Lina Zhang
- Department of Critical Care Medicine, Xiangya HospitalCentral South UniversityChangshaChina
- National Clinical Research Center for Geriatric DisordersChangshaHunanChina
- Hunan Provincial Clinical Research Center for Critical Care MedicineChangshaHunanChina
| | - Zheren Tan
- Department of Critical Care Medicine, Xiangya HospitalCentral South UniversityChangshaChina
- National Clinical Research Center for Geriatric DisordersChangshaHunanChina
- Hunan Provincial Clinical Research Center for Critical Care MedicineChangshaHunanChina
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Bajaj S, Mahesh R. Converged avenues: depression and Alzheimer's disease- shared pathophysiology and novel therapeutics. Mol Biol Rep 2024; 51:225. [PMID: 38281208 DOI: 10.1007/s11033-023-09170-1] [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: 09/06/2023] [Accepted: 12/15/2023] [Indexed: 01/30/2024]
Abstract
Depression, a highly prevalent disorder affecting over 280 million people worldwide, is comorbid with many neurological disorders, particularly Alzheimer's disease (AD). Depression and AD share overlapping pathophysiology, and the search for accountable biological substrates made it an essential and intriguing field of research. The paper outlines the neurobiological pathways coinciding with depression and AD, including neurotrophin signalling, the hypothalamic-pituitary-adrenal axis (HPA), cellular apoptosis, neuroinflammation, and other aetiological factors. Understanding overlapping pathways is crucial in identifying common pathophysiological substrates that can be targeted for effective management of disease state. Antidepressants, particularly monoaminergic drugs (first-line therapy), are shown to have modest or no clinical benefits. Regardless of the ineffectiveness of conventional antidepressants, these drugs remain the mainstay for treating depressive symptoms in AD. To overcome the ineffectiveness of traditional pharmacological agents in treating comorbid conditions, a novel therapeutic class has been discussed in the paper. This includes neurotransmitter modulators, glutamatergic system modulators, mitochondrial modulators, antioxidant agents, HPA axis targeted therapy, inflammatory system targeted therapy, neurogenesis targeted therapy, repurposed anti-diabetic agents, and others. The primary clinical challenge is the development of therapeutic agents and the effective diagnosis of the comorbid condition for which no specific diagnosable scale is present. Hence, introducing Artificial Intelligence (AI) into the healthcare system is revolutionary. AI implemented with interdisciplinary strategies (neuroimaging, EEG, molecular biomarkers) bound to have accurate clinical interpretation of symptoms. Moreover, AI has the potential to forecast neurodegenerative and psychiatric illness much in advance before visible/observable clinical symptoms get precipitated.
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Affiliation(s)
- Shivanshu Bajaj
- Department of Pharmacy, Birla Institute of Technology and Science (BITS), Pilani, 333031, Rajasthan, India
| | - Radhakrishnan Mahesh
- Department of Pharmacy, Birla Institute of Technology and Science (BITS), Pilani, 333031, Rajasthan, India.
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Richter AL, Diepeveen-de Bruin M, Balvers MG, de Groot LC, De Deyn PP, Engelborghs S, Witkamp RF, Vermeiren Y. Association between Low Vitamin D Status, Serotonin, and Clinico-Biobehavioral Parameters in Alzheimer's Disease. Dement Geriatr Cogn Disord 2023; 52:318-326. [PMID: 37806302 PMCID: PMC10911141 DOI: 10.1159/000534492] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 05/22/2023] [Accepted: 10/05/2023] [Indexed: 10/10/2023] Open
Abstract
INTRODUCTION Studies suggest a role of vitamin D in the progression and symptomatology of Alzheimer's disease (AD), with few in vitro studies pointing to effects on serotonergic and amyloidogenic turnover. However, limited data exist in AD patients on the potential association with cognition and behavioral and psychological signs and symptoms of dementia (BPSD). In this retrospective cross-sectional study, we, therefore, explored potential correlations of serum 25-hydroxyvitamin D3 (25(OH)D3) concentrations, indicative of vitamin D status, with serum serotonin (5-hydroxytryptamine, 5-HT) levels, cognitive/BPSD scorings, and cerebrospinal fluid (CSF) biomarker levels. METHODS Frozen serum samples of 25 well-characterized AD subjects as part of a previous BPSD cohort were analyzed, of which 15 had a neuropathologically confirmed diagnosis. Serum 25(OH)D3 levels were analyzed by means of LC-MS/MS, whereas 5-HT concentrations were quantified by competitive ELISA. RESULTS Among AD patients, vitamin D deficiency was highly prevalent, defined as levels below 50 nmol/L. Regression analyses, adjusted for age, gender, and psychotropic medications, revealed that serum 25(OH)D3 and 5-HT levels were positively associated (p = 0.012). Furthermore, serum 25(OH)D3 concentrations correlated inversely with CSF amyloid-beta (Aβ1-42) levels (p = 0.006), and serum 5-HT levels correlated positively with aggressiveness (p = 0.001), frontal behavior (p = 0.001), depression (p = 0.004), and partly with cognitive performance (p < 0.005). Lastly, AD patients on cholinesterase inhibitors had higher serum 25(OH)D3 (p = 0.030) and lower serum 5-HT (p = 0.012) levels. CONCLUSIONS The molecular associations between low vitamin D status, serum 5-HT, and CSF Aβ1-42 levels are highly remarkable, warranting further mechanistic and intervention studies to disclose potential involvement in the clinico-biobehavioral pathophysiology of AD.
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Affiliation(s)
- Anna-Lena Richter
- Division of Human Nutrition and Health, Chair Group Nutritional Biology, Wageningen University and Research (WUR), Wageningen, The Netherlands
| | - Marlies Diepeveen-de Bruin
- Division of Human Nutrition and Health, Chair Group Nutritional Biology, Wageningen University and Research (WUR), Wageningen, The Netherlands
| | - Michiel G.J. Balvers
- Division of Human Nutrition and Health, Chair Group Nutritional Biology, Wageningen University and Research (WUR), Wageningen, The Netherlands
| | - Lisette C.P.G.M. de Groot
- Division of Human Nutrition and Health, Chair Group Nutritional Biology, Wageningen University and Research (WUR), Wageningen, The Netherlands
| | - Peter Paul De Deyn
- Reference Center for Biological Markers of Dementia (BIODEM), Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Department of Neurology and Memory Clinic, Middelheim General Hospital, Antwerp, Belgium
- Department of Neurology and Alzheimer Research Center, University of Groningen and University Medical Center Groningen (UMCG), Groningen, The Netherlands
| | - Sebastiaan Engelborghs
- Reference Center for Biological Markers of Dementia (BIODEM), Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Neuroprotection and Neuromodulation (NEUR) Research Group, Center for Neurosciences (C4N), Vrije Universiteit Brussel, Brussels, Belgium
- Department of Neurology and Bru-BRAIN, Universitair Ziekenhuis Brussel, Brussels, Belgium
| | - Renger F. Witkamp
- Division of Human Nutrition and Health, Chair Group Nutritional Biology, Wageningen University and Research (WUR), Wageningen, The Netherlands
| | - Yannick Vermeiren
- Division of Human Nutrition and Health, Chair Group Nutritional Biology, Wageningen University and Research (WUR), Wageningen, The Netherlands
- Reference Center for Biological Markers of Dementia (BIODEM), Laboratory of Neurochemistry and Behavior, Institute Born-Bunge, University of Antwerp, Antwerp, Belgium
- Faculty of Medicine and Health Sciences, Translational Neurosciences, University of Antwerp, Antwerp, Belgium
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Nageeb Hasan SM, Clarke CL, McManamon Strand TP, Bambico FR. Putative pathological mechanisms of late-life depression and Alzheimer's Disease. Brain Res 2023:148423. [PMID: 37244602 DOI: 10.1016/j.brainres.2023.148423] [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: 03/02/2023] [Revised: 05/18/2023] [Accepted: 05/22/2023] [Indexed: 05/29/2023]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder that is characterized by progressive impairment in cognition and memory. AD is accompanied by several neuropsychiatric symptoms, with depression being the most prominent. Although depression has long been known to be associated with AD, controversial findings from preclinical and clinical studies have obscured the precise nature of this association. However recent evidence suggests that depression could be a prodrome or harbinger of AD. Evidence indicates that the major central serotonergic nucleus-the dorsal raphe nucleus (DRN)-shows very early AD pathology: neurofibrillary tangles made of hyperphosphorylated tau protein and degenerated neurites. AD and depression share common pathophysiologies, including functional deficits of the serotonin (5-HT) system. 5-HT receptors have modulatory effects on the progression of AD pathology i.e., reduction in Aβ load, increased hyper-phosphorylation of tau, decreased oxidative stress etc. Moreover, preclinical models show a role for specific channelopathies that result in abnormal regional activational and neuroplasticity patterns. One of these concerns the pathological upregulation of the small conductance calcium-activated potassium (SK) channel in corticolimbic structure. This has also been observed in the DRN in both diseases. The SKC is a key regulator of cell excitability and long-term potentiation (LTP). SKC over-expression is positively correlated with aging and cognitive decline, and is evident in AD. Pharmacological blockade of SKCs has been reported to reverse symptoms of depression and AD. Thus, aberrant SKC functioning could be related to depression pathophysiology and diverts its late-life progression towards the development of AD. We summarize findings from preclinical and clinical studies suggesting a molecular linkage between depression and AD pathology. We also provide a rationale for considering SKCs as a novel pharmacological target for the treatment of AD-associated symptoms.
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Affiliation(s)
- S M Nageeb Hasan
- Department of Psychology, Memorial University of Newfoundland and Labrador, Newfoundland and Labrador, A1B3Xs, Canada.
| | - Courtney Leigh Clarke
- Department of Psychology, Memorial University of Newfoundland and Labrador, Newfoundland and Labrador, A1B3Xs, Canada
| | | | - Francis Rodriguez Bambico
- Department of Psychology, Memorial University of Newfoundland and Labrador, Newfoundland and Labrador, A1B3Xs, Canada; Behavioural Neurobiology Laboratory, Centre for Addiction and Mental Health, Toronto, ON, M5T1R8, Canada
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Tancheva L, Lazarova M, Velkova L, Dolashki A, Uzunova D, Minchev B, Petkova-Kirova P, Hassanova Y, Gavrilova P, Tasheva K, Taseva T, Hodzhev Y, Atanasov AG, Stefanova M, Alexandrova A, Tzvetanova E, Atanasov V, Kalfin R, Dolashka P. Beneficial Effects of Snail Helix aspersa Extract in an Experimental Model of Alzheimer’s Type Dementia. J Alzheimers Dis 2022; 88:155-175. [DOI: 10.3233/jad-215693] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Abstract
Background: Alzheimer’s disease (AD) is a complex neurodegenerative disease with multifactorial etiology, unsatisfactory treatment, and a necessity for broad-spectrum active substances for cure. The mucus from Helix aspersa snail is a mixture of bioactive molecules with antimicrobial, anti-inflammatory, antioxidant, and anti-apoptotic effects. So far there are no data concerning the capacity of snail extract (SE) to affect neurodegenerative disorders. Objective: The effects of SE from Helix aspersa on learning and memory deficits in Alzheimer’s type dementia (ATD) induced by scopolamine (Sco) in male Wistar rats were examined and some mechanisms of action underlying these effects were evaluated. Methods: SE (0.5 mL/100 g) was applied orally through a food tube for 16 consecutive days: 5 days before and 11 days simultaneously with Sco (2 mg/kg, intraperitoneally). At the end of Sco treatment, using behavioral methods, we evaluated memory performance. Additionally, in cortex and hippocampus the acetylcholinesterase (AChE) activity, acetylcholine and monoamines (dopamine, noradrenaline, and serotonin) content, levels of main oxidative stress markers, and expression of brain-derived neurotrophic factor (BDNF) and cAMP response element-binding protein (CREB) were determined. Results: We demonstrated that, according to all behavioral tests used, SE significantly improved the cognitive deficits induced by Sco. Furthermore, SE possessed AChE inhibitory activity, moderate antioxidant properties and the ability to modulate monoamines content in two brain structures. Moreover, multiple SE applications not only restored the depressed by Sco expression of CREB and BDNF, but significantly upregulated it. Conclusion: Summarizing results, we conclude that complex mechanisms underlie the beneficial effects of SE on impaired memory in Alzheimer’s type dementia.
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Affiliation(s)
- Lyubka Tancheva
- Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria
- Weston Professor of Weizmann Institute of Science, Israel
| | - Maria Lazarova
- Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria
| | - Lyudmila Velkova
- Institute of Organic Chemistry with Center for Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Alexander Dolashki
- Institute of Organic Chemistry with Center for Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Diamara Uzunova
- Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria
| | - Borislav Minchev
- Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria
| | | | - Yozljam Hassanova
- Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria
| | - Petja Gavrilova
- Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria
| | - Krasimira Tasheva
- Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Teodora Taseva
- Institute of Plant Physiology and Genetics, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Yordan Hodzhev
- National Center for Infectious and Parasitic Diseases, Sofia, Bulgaria
| | - Atanas G. Atanasov
- Ludwig Boltzmann Institute for Digital Health and Patient Safety, Medical University of Vienna, Vienna, Austria
- Institute of Genetics and Animal Biotechnology of the Polish Academy of Sciences, Jastrzebiec, Magdalenka, Poland
- Department of Pharmaceutical Sciences, University of Vienna, Vienna, Austria
| | | | - Albena Alexandrova
- Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria
| | - Elina Tzvetanova
- Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria
| | - Ventseslav Atanasov
- Institute of Organic Chemistry with Center for Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
| | - Reni Kalfin
- Institute of Neurobiology, Bulgarian Academy of Science, Sofia, Bulgaria
- Department of Healthcare, South-West University “Neofit Rilski”, Blagoevgrad, Bulgaria
| | - Pavlina Dolashka
- Institute of Organic Chemistry with Center for Phytochemistry, Bulgarian Academy of Sciences, Sofia, Bulgaria
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7
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Ghaheri S, Niapour A, Sakhaie N, Sadegzadeh F, Saadati H. Postnatal depletion of serotonin affects the morphology of neurons and the function of the hippocampus in male rats. Int J Dev Neurosci 2022; 82:222-230. [PMID: 35181916 DOI: 10.1002/jdn.10174] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/27/2021] [Revised: 02/08/2022] [Accepted: 02/15/2022] [Indexed: 11/09/2022] Open
Abstract
Serotonin (5-HT) is an essential neurotransmitter for the refined organization of the cerebral cortex. Studies have suggested that altered serotonin signaling contributes to cognitive impairment and psychiatric disorders. However, the exact role of this neurotransmitter on the development of hippocampal neurons is not recognized. Here we aimed to examine the effects of the para- chlorophenylalanine (PCPA; 100mg/kg/daily, s.c during the postnatal days 10-20), a reversible inhibitor of 5-HT synthesis, on the serotonin level of the hippocampal and prefrontal cortex. We also focused on the morphology of the neurons in the hippocampus and spatial learning and memory. Our results indicated that the administration of PCPA led to a decrease in serotonin levels in the hippocampus and prefrontal cortex. Postnatal serotonin depletion also induced subtle alterations in the neuronal populations of the hippocampus and impaired spatial memory in the adulthood period of life. We found that critical developmental periods of serotonin depletion caused degeneration and swelling of neurons as well as significant neuronal loss in the hippocampal CA1, CA3, and dentate gyrus (DG) areas. Thus, serotonin, a strikingly important neurotransmitter, can affect neuronal morphology, development, and hippocampal-dependent memory.
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Affiliation(s)
- Safa Ghaheri
- Students Research Committee, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Ali Niapour
- Research Laboratory for Embryology and Stem Cells, Department of Anatomical Sciences, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Nona Sakhaie
- Students Research Committee, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Farshid Sadegzadeh
- Students Research Committee, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran
| | - Hakimeh Saadati
- Department of Physiology, School of Medicine, Ardabil University of Medical Sciences, Ardabil, Iran.,Pharmaceutical Sciences Research Center, Ardabil University of Medical Sciences, Ardabil, Iran
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Monteiro-Fernandes D, Silva JM, Soares-Cunha C, Dalla C, Kokras N, Arnaud F, Billiras R, Zhuravleva V, Waites C, Bretin S, Sousa N, Sotiropoulos I. Allosteric modulation of AMPA receptors counteracts Tau-related excitotoxic synaptic signaling and memory deficits in stress- and Aβ-evoked hippocampal pathology. Mol Psychiatry 2021; 26:5899-5911. [PMID: 32467647 DOI: 10.1038/s41380-020-0794-5] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/01/2019] [Revised: 05/12/2020] [Accepted: 05/18/2020] [Indexed: 12/12/2022]
Abstract
Despite considerable progress in the understanding of its neuropathology, Alzheimer's disease (AD) remains a complex disorder with no effective treatment that counteracts the memory deficits and the underlying synaptic malfunction triggered by the accumulation of amyloid beta (Aβ) and Tau protein. Mounting evidence supports a precipitating role for chronic environmental stress and glutamatergic excitotoxicity in AD, suggesting that targeting of glutamate receptor signaling may be a promising approach against both stress and AD pathologies. In light of the limited cognitive benefit of the direct antagonism of NMDA receptors in AD, we here focus on an alternative way to modify glutamatergic signaling through positive allosteric modulation of AMPA receptors, by the use of a PAM-AMPA compound. Using non-transgenic animal model of Aβ oligomer injection as well as the combined stress and Aβ i.c.v. infusion, we demonstrate that positive allosteric modulation of AMPA receptors by PAM-AMPA treatment reverted memory, but not mood, deficits. Furthermore, PAM-AMPA treatment reverted stress/Aβ-driven synaptic missorting of Tau and associated Fyn/GluN2B-driven excitotoxic synaptic signaling accompanied by recovery of neurotransmitter levels in the hippocampus. Our findings suggest that positive allosteric modulation of AMPA receptors restores synaptic integrity and cognitive performance in stress- and Aβ-evoked hippocampal pathology. As the prevalence of AD is increasing at an alarming rate, novel therapeutic targeting of glutamatergic signaling should be further explored against the early stages of AD synaptic malfunction with the goal of attenuating further synaptic damage before it becomes irreversible.
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Affiliation(s)
- Daniela Monteiro-Fernandes
- Life and Health Sciences Research Institute (ICVS), Medical School, University of Minho, Campus Gualtar, Minho, Portugal
- ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Joana Margarida Silva
- Life and Health Sciences Research Institute (ICVS), Medical School, University of Minho, Campus Gualtar, Minho, Portugal
- ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Carina Soares-Cunha
- Life and Health Sciences Research Institute (ICVS), Medical School, University of Minho, Campus Gualtar, Minho, Portugal
- ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Christina Dalla
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - Nikolaos Kokras
- Department of Pharmacology, Medical School, National and Kapodistrian University of Athens, Athens, Greece
- First Department of Psychiatry, Eginition Hospital, Medical School, National and Kapodistrian University of Athens, Athens, Greece
| | - François Arnaud
- Pôle Innovation Thérapeutique Neuropsychiatrie, Institut de Recherches Internationales Servier, Suresnes, France
| | - Rodolphe Billiras
- Pôle Innovation Thérapeutique Neuropsychiatrie, Institut de Recherches Internationales Servier, Suresnes, France
| | - Viktoriya Zhuravleva
- Neurobiology and Behavior Graduate Program, Columbia University, New York, NY, USA
| | - Clarissa Waites
- Department of Pathology and Cell Biology, Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA
- Department of Neuroscience, Columbia University, New York, NY, USA
| | - Sylvie Bretin
- Pôle Innovation Thérapeutique Neuropsychiatrie, Institut de Recherches Internationales Servier, Suresnes, France
| | - Nuno Sousa
- Life and Health Sciences Research Institute (ICVS), Medical School, University of Minho, Campus Gualtar, Minho, Portugal
- ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal
| | - Ioannis Sotiropoulos
- Life and Health Sciences Research Institute (ICVS), Medical School, University of Minho, Campus Gualtar, Minho, Portugal.
- ICVS/3B's-PT Government Associate Laboratory, Braga/Guimarães, Portugal.
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Inhibition of Astrocytic Histamine N-Methyltransferase as a Possible Target for the Treatment of Alzheimer's Disease. Biomolecules 2021; 11:biom11101408. [PMID: 34680041 PMCID: PMC8533269 DOI: 10.3390/biom11101408] [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: 08/10/2021] [Revised: 09/20/2021] [Accepted: 09/22/2021] [Indexed: 12/03/2022] Open
Abstract
Alzheimer’s disease (AD) represents the principal cause of dementia among the elderly. Great efforts have been established to understand the physiopathology of AD. Changes in neurotransmitter systems in patients with AD, including cholinergic, GABAergic, serotoninergic, noradrenergic, and histaminergic changes have been reported. Interestingly, changes in the histaminergic system have been related to cognitive impairment in AD patients. The principal pathological changes in the brains of AD patients, related to the histaminergic system, are neurofibrillary degeneration of the tuberomammillary nucleus, the main source of histamine in the brain, low histamine levels, and altered signaling of its receptors. The increase of histamine levels can be achieved by inhibiting its degrading enzyme, histamine N-methyltransferase (HNMT), a cytoplasmatic enzyme located in astrocytes. Thus, increasing histamine levels could be employed in AD patients as co-therapy due to their effects on cognitive functions, neuroplasticity, neuronal survival, neurogenesis, and the degradation of amyloid beta (Aβ) peptides. In this sense, the evaluation of the impact of HNMT inhibitors on animal models of AD would be interesting, consequently highlighting its relevance.
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Solas M, Van Dam D, Janssens J, Ocariz U, Vermeiren Y, De Deyn PP, Ramirez MJ. 5-HT 7 receptors in Alzheimer's disease. Neurochem Int 2021; 150:105185. [PMID: 34555475 DOI: 10.1016/j.neuint.2021.105185] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Revised: 09/01/2021] [Accepted: 09/12/2021] [Indexed: 10/20/2022]
Abstract
Even though the involvement of serotonin (5-hydroxytryptamine; 5-HT) and its receptors in Alzheimer's disease (AD) is widely accepted, data on the expression and the role of 5-HT7 receptors in AD is relatively limited. Therefore, the objective of the present work was to study the expression of serotonergic 5-HT7 receptors in postmortem samples of AD brains and correlate it with neurotransmitter levels, cognition and behavior. The study population consisted of clinically well-characterized and neuropathologically confirmed AD patients (n = 42) and age-matched control subjects (n = 18). Reverse-transcription quantitative polymerase chain reaction (RT-qPCR) and high-performance liquid chromatography were performed on Brodmann area (BA) 7, BA10, BA22, BA24, hippocampus, amygdala, thalamus and cerebellum to measure mRNA levels of 5-HT7 receptors (HTR7), as well as the concentrations of various monoamine neurotransmitters and their metabolites. Decreased levels of HTR7 mRNA were observed in BA10. A significant association was observed between HTR7 levels in BA10 and BEHAVE-AD cluster B (hallucinations) (rs(28) = 0.444, P < 0.05). In addition, a negative correlation was observed between HTR7 levels in BA10 and both MHPG concentrations in this brain region (rs(45) = -0.311; P < 0.05), and DOPAC levels in the amygdala (rs(42) = -0.311; P < 0.05). Quite surprisingly, no association was found between HTR7 levels and cognitive status. Altogether, this study supports the notion of the involvement of 5-HT7 receptors in psychotic symptoms in AD, suggesting the interest of testing antagonist acting at this receptor to specifically treat psychotic symptoms in this illness.
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Affiliation(s)
- Maite Solas
- Dpt Pharmacology and Toxicology, University of Navarra, 31008, Pamplona, Spain; IdISNA, Navarra Institute for Health Research, 31008, Pamplona, Spain
| | - Debby Van Dam
- Laboratory of Neurochemistry and Behavior, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Department of Neurology and Alzheimer Center Groningen, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Jana Janssens
- Laboratory of Neurochemistry and Behavior, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium
| | - U Ocariz
- Dpt Pharmacology and Toxicology, University of Navarra, 31008, Pamplona, Spain
| | - Yannick Vermeiren
- Laboratory of Neurochemistry and Behavior, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Department of Neurology and Alzheimer Center Groningen, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Peter Paul De Deyn
- Laboratory of Neurochemistry and Behavior, Department of Biomedical Sciences, University of Antwerp, Antwerp, Belgium; Department of Neurology and Alzheimer Center Groningen, University of Groningen and University Medical Center Groningen, Groningen, the Netherlands
| | - Maria J Ramirez
- Dpt Pharmacology and Toxicology, University of Navarra, 31008, Pamplona, Spain; IdISNA, Navarra Institute for Health Research, 31008, Pamplona, Spain.
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11
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Ying Y, Wang JZ. Illuminating Neural Circuits in Alzheimer's Disease. Neurosci Bull 2021; 37:1203-1217. [PMID: 34089505 DOI: 10.1007/s12264-021-00716-6] [Citation(s) in RCA: 16] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/30/2020] [Accepted: 03/06/2021] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) is the most common neurodegenerative disorder and there is currently no cure. Neural circuit dysfunction is the fundamental mechanism underlying the learning and memory deficits in patients with AD. Therefore, it is important to understand the structural features and mechanisms underlying the deregulated circuits during AD progression, by which new tools for intervention can be developed. Here, we briefly summarize the most recently established cutting-edge experimental approaches and key techniques that enable neural circuit tracing and manipulation of their activity. We also discuss the advantages and limitations of these approaches. Finally, we review the applications of these techniques in the discovery of circuit mechanisms underlying β-amyloid and tau pathologies during AD progression, and as well as the strategies for targeted AD treatments.
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Affiliation(s)
- Yang Ying
- Department of Pathophysiology, School of Basic Medicine, Ministry of Education Key Laboratory for Neurological Disorders, Hubei Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
| | - Jian-Zhi Wang
- Department of Pathophysiology, School of Basic Medicine, Ministry of Education Key Laboratory for Neurological Disorders, Hubei Key Laboratory for Neurological Disorders, Tongji Medical College, Huazhong University of Science and Technology, Wuhan, 430030, China.
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12
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Mohamad Rezaei R, Shiravi A, Seyedinia SA, Moradi Kor N, Vafaei AA, Rashidy-Pour A. Role of Hippocampal 5-HT6 Receptors in Glucocorticoid-Induced Enhancement of Memory Consolidation in Rats. Basic Clin Neurosci 2021; 11:507-516. [PMID: 33613889 PMCID: PMC7878042 DOI: 10.32598/bcn.9.10.410] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Revised: 08/27/2018] [Accepted: 08/20/2019] [Indexed: 11/24/2022] Open
Abstract
Introduction: of the study: Post-training administration of glucocorticoids enhance memory consolidation of inhibitory avoidance learning. Given the involvement of 5-HT6 receptors in memory processing and the interaction of glucocorticoids with the brain serotonergic system in modulating memory processing, we investigated whether the effect of glucocorticoids on the consolidation of emotionally arousing training depends on hippocampal 5-HT6 receptors. Methods: Rats were trained in an inhibitory avoidance task and immediately received the systemic injections of corticosterone (CORT) as well as the intra-hippocampal injections of 5-HT receptors agonist or antagonist. The memory retention test was done 48 hours after training and immediately after the behavioral test, the animals were sacrificed and the hippocampi (left and right) rapidly dissected out for molecular studies. Results: Post-training injections of different doses of CORT (1.25, 2.5, 5, and 10 mg/kg) enhanced memory retention in a dose-dependent manner. The CORT-induced enhancement of memory consolidation was blocked by bilateral intra-hippocampal injections of 5-HT6 receptor antagonist SB271046 (5 or 10 ng/per side), but not agonist EMD386088 (5 or 10 ng/per side). Furthermore, systemic CORT reduced 5-HT6 receptor mRNA and protein expression in the hippocampus. Both doses of 5-HT6 receptor agonist and antagonist significantly enhanced and reduced the expression of the 5-HT6 receptor, respectively, and both ligands at the higher dose (10 ng) enhanced memory consolidation. Moreover, CORT injection attenuated and enhanced, respectively, the effects of agonist and antagonist on 5-HT6 receptor expression. Conclusion: These behavioral and molecular findings indicated an interaction between glucocorticoids and hippocampal 5-HT6 receptors in the consolidation of emotionally arousing experiences.
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Affiliation(s)
| | | | - Seyed Ali Seyedinia
- Student Research Committee, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Nasroallah Moradi Kor
- Student Research Committee, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran.,Laboratory of Learning and Memory, Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran
| | - Abbas Ali Vafaei
- Laboratory of Learning and Memory, Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran.,Department of Physiology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
| | - Ali Rashidy-Pour
- Laboratory of Learning and Memory, Research Center of Physiology, Semnan University of Medical Sciences, Semnan, Iran.,Department of Physiology, Faculty of Medicine, Semnan University of Medical Sciences, Semnan, Iran
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Manzoor S, Hoda N. A comprehensive review of monoamine oxidase inhibitors as Anti-Alzheimer's disease agents: A review. Eur J Med Chem 2020; 206:112787. [PMID: 32942081 DOI: 10.1016/j.ejmech.2020.112787] [Citation(s) in RCA: 108] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2020] [Revised: 07/22/2020] [Accepted: 08/25/2020] [Indexed: 02/07/2023]
Abstract
Monoamine oxidases (MAO-A and MAO-B) are mammalian flavoenzyme, which catalyze the oxidative deamination of several neurotransmitters like norepinephrine, dopamine, tyramine, serotonin, and some other amines. The oxidative deamination produces several harmful side products like ammonia, peroxides, and aldehydes during the biochemical reaction. The concentration of biochemical neurotransmitter alteration in the brain by MAO is directly related with several neurological disorders like Alzheimer's disease and Parkinson's disease (PD). Activated MAO also contributes to the amyloid beta (Aβ) aggregation by two successive cleft β-secretase and γ-secretase of amyloid precursor protein (APP). Additionally, activated MAO is also involved in aggregation of neurofibrillary tangles and cognitive destruction through the cholinergic neuronal damage and disorder of the cholinergic system. MAO inhibition has general anti-Alzheimer's disease effect as a consequence of oxidative stress reduction prompted by MAO enzymes. In this review, we outlined and addressed recent understanding on MAO enzymes such as their structure, physiological function, catalytic mechanism, and possible therapeutic goals in AD. In addition, it also highlights the current development and discovery of potential MAO inhibitors (MAOIs) from various chemical scaffolds.
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Affiliation(s)
- Shoaib Manzoor
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi, 110025, India
| | - Nasimul Hoda
- Drug Design and Synthesis Laboratory, Department of Chemistry, Jamia Millia Islamia, New Delhi, 110025, India.
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14
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Joshi A, Wang DH, Watterson S, McClean PL, Behera CK, Sharp T, Wong-Lin K. Opportunities for multiscale computational modelling of serotonergic drug effects in Alzheimer's disease. Neuropharmacology 2020; 174:108118. [PMID: 32380022 PMCID: PMC7322519 DOI: 10.1016/j.neuropharm.2020.108118] [Citation(s) in RCA: 9] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2019] [Revised: 04/13/2020] [Accepted: 04/27/2020] [Indexed: 12/17/2022]
Abstract
Alzheimer's disease (AD) is an age-specific neurodegenerative disease that compromises cognitive functioning and impacts the quality of life of an individual. Pathologically, AD is characterised by abnormal accumulation of beta-amyloid (Aβ) and hyperphosphorylated tau protein. Despite research advances over the last few decades, there is currently still no cure for AD. Although, medications are available to control some behavioural symptoms and slow the disease's progression, most prescribed medications are based on cholinesterase inhibitors. Over the last decade, there has been increased attention towards novel drugs, targeting alternative neurotransmitter pathways, particularly those targeting serotonergic (5-HT) system. In this review, we focused on 5-HT receptor (5-HTR) mediated signalling and drugs that target these receptors. These pathways regulate key proteins and kinases such as GSK-3 that are associated with abnormal levels of Aβ and tau in AD. We then review computational studies related to 5-HT signalling pathways with the potential for providing deeper understanding of AD pathologies. In particular, we suggest that multiscale and multilevel modelling approaches could potentially provide new insights into AD mechanisms, and towards discovering novel 5-HTR based therapeutic targets. Alzheimer's disease (AD) drug treatment is limited, and alternatives are needed. Serotonin (5-HT) mediated signalling pathways may regulate Aβ and tau levels. 5-HT based drugs have the potential to provide as novel therapeutics for AD. Complex 5-HT signalling mechanisms for AD and related drugs hinder understanding. Multiscale models may offer insights into mechanisms and therapeutic targets.
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Affiliation(s)
- Alok Joshi
- Intelligent Systems Research Centre, Ulster University, Derry~Londonderry, Northern Ireland, UK.
| | - Da-Hui Wang
- State Key Laboratory of Cognitive Neuroscience and Learning, Beijing Normal University, Beijing, China; School of System Science, Beijing Normal University, Beijing, China
| | - Steven Watterson
- Northern Ireland Centre for Stratified Medicine, Biomedical Sciences Research Institute, Ulster University, Derry~Londonderry, Northern Ireland, UK
| | - Paula L McClean
- Northern Ireland Centre for Stratified Medicine, Biomedical Sciences Research Institute, Ulster University, Derry~Londonderry, Northern Ireland, UK
| | - Chandan K Behera
- Intelligent Systems Research Centre, Ulster University, Derry~Londonderry, Northern Ireland, UK
| | - Trevor Sharp
- Department of Pharmacology, University of Oxford, Oxford, UK
| | - KongFatt Wong-Lin
- Intelligent Systems Research Centre, Ulster University, Derry~Londonderry, Northern Ireland, UK.
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15
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Tai Chi Training Evokes Significant Changes in Brain White Matter Network in Older Women. Healthcare (Basel) 2020; 8:healthcare8010057. [PMID: 32182844 PMCID: PMC7151065 DOI: 10.3390/healthcare8010057] [Citation(s) in RCA: 16] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/20/2020] [Revised: 03/05/2020] [Accepted: 03/05/2020] [Indexed: 12/20/2022] Open
Abstract
Background: Cognitive decline is age relevant and it can start as early as middle age. The decline becomes more obvious among older adults, which is highly associated with increased risk of developing dementia (e.g., Alzheimer’s disease). White matter damage was found to be related to cognitive decline through aging. The purpose of the current study was to compare the effects of Tai Chi (TC) versus walking on the brain white matter network among Chinese elderly women. Methods: A cross-sectional study was conducted where 42 healthy elderly women were included. Tai Chi practitioners (20 females, average age: 62.9 ± 2.38 years, education level 9.05 ± 1.8 years) and the matched walking participants (22 females, average age: 63.27 ± 3.58 years, educational level: 8.86 ± 2.74 years) underwent resting-state functional magnetic resonance imaging (rsfMRI) scans. Diffusion tensor imaging (DTI) and graph theory were employed to study the data, construct the white matter matrix, and compare the brain network attributes between the two groups. Results: Results from graph-based analyses showed that the small-world attributes were higher for the TC group than for the walking group (p < 0.05, Cohen’s d = 1.534). Some effects were significant (p < 0.001) with very large effect sizes. Meanwhile, the aggregation coefficient and local efficiency attributes were also higher for the TC group than for the walking group (p > 0.05). However, no significant difference was found between the two groups in node attributes and edge analysis. Conclusion: Regular TC training is more conducive to optimize the brain functioning and networking of the elderly. The results of the current study help to identify the mechanisms underlying the cognitive protective effects of TC.
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16
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Bostancıklıoğlu M. Optogenetic stimulation of serotonin nuclei retrieve the lost memory in Alzheimer's disease. J Cell Physiol 2019; 235:836-847. [PMID: 31332785 DOI: 10.1002/jcp.29077] [Citation(s) in RCA: 17] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/07/2019] [Accepted: 06/21/2019] [Indexed: 12/29/2022]
Abstract
How are memories stored and retrieved? It was one of the most discussed questions in the past century by neuroscientists. Leading studies of the period brought two different explanations to this question: The first statement considers memory as a physiological change in the brain and suggest that the retrieval of memory is only occurred by the same physiologic changes observed during the memory formation, while the second suggests that memory is a psychic mood stored in mind and the retrieval of memory is occurred by mystical energy fluctuations. Although the exact reason and the pathogenesis of Alzheimer's disease have not yet been fully understood, the approaches that centered the retrieval strategy of lost memory constitutes the basis of the treatment strategies in Alzheimer's disease today. The majority of treatment studies has based on the manipulation of the cholinergic system; however, although serotonin has mnemonic effects, its role in the pathogenesis of Alzheimer's disease has not been investigated as much as the cholinergic system. Here we show how serotonin affects the pathogenesis of Alzheimer's disease in a comprehensive perspective and we suggest that the optogenetics manipulation of serotonin nuclei retrieve the lost memory by closing the inward-rectifier potassium channel Kir2 on the memory engram cells. Also, we raise the possible effects of serotonin on the memory engram cells and the interactions between the amyloid-centric hypothesis of Alzheimer's disease and the memory engram hypothesis to explain the pathophysiology of memory loss in Alzheimer's disease.
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17
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Epigenetic Modulation on Tau Phosphorylation in Alzheimer's Disease. Neural Plast 2019; 2019:6856327. [PMID: 31093272 PMCID: PMC6481020 DOI: 10.1155/2019/6856327] [Citation(s) in RCA: 14] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/11/2019] [Accepted: 03/28/2019] [Indexed: 12/14/2022] Open
Abstract
Tau hyperphosphorylation is a typical pathological change in Alzheimer's disease (AD) and is involved in the early onset and progression of AD. Epigenetic modification refers to heritable alterations in gene expression that are not caused by direct changes in the DNA sequence of the gene. Epigenetic modifications, such as noncoding RNA regulation, DNA methylation, and histone modification, can directly or indirectly affect the regulation of tau phosphorylation, thereby participating in AD development and progression. This review summarizes the current research progress on the mechanisms of epigenetic modification associated with tau phosphorylation.
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18
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Gilmour G, Porcelli S, Bertaina-Anglade V, Arce E, Dukart J, Hayen A, Lobo A, Lopez-Anton R, Merlo Pich E, Pemberton DJ, Havenith MN, Glennon JC, Harel BT, Dawson G, Marston H, Kozak R, Serretti A. Relating constructs of attention and working memory to social withdrawal in Alzheimer’s disease and schizophrenia: issues regarding paradigm selection. Neurosci Biobehav Rev 2019; 97:47-69. [DOI: 10.1016/j.neubiorev.2018.09.025] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/06/2017] [Revised: 08/29/2018] [Accepted: 09/27/2018] [Indexed: 12/12/2022]
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19
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Social brain, social dysfunction and social withdrawal. Neurosci Biobehav Rev 2019; 97:10-33. [DOI: 10.1016/j.neubiorev.2018.09.012] [Citation(s) in RCA: 132] [Impact Index Per Article: 26.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2017] [Revised: 05/31/2018] [Accepted: 09/17/2018] [Indexed: 01/07/2023]
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20
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Zhou C, Chao F, Zhang Y, Jiang L, Zhang L, Fan J, Wu Y, Dou X, Tang Y. Fluoxetine delays the cognitive function decline and synaptic changes in a transgenic mouse model of early Alzheimer's disease. J Comp Neurol 2019; 527:1378-1387. [DOI: 10.1002/cne.24616] [Citation(s) in RCA: 20] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/11/2018] [Revised: 12/11/2018] [Accepted: 12/18/2018] [Indexed: 11/11/2022]
Affiliation(s)
- Chun‐ni Zhou
- Department of Histology and EmbryologyChongqing Medical University Chongqing China
- Laboratory of Stem Cell and Tissue EngineeringChongqing Medical University Chongqing China
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine, Ministry of EducationChongqing Medical University Chongqing China
| | - Feng‐lei Chao
- Department of Histology and EmbryologyChongqing Medical University Chongqing China
- Laboratory of Stem Cell and Tissue EngineeringChongqing Medical University Chongqing China
| | - Yi Zhang
- Department of Histology and EmbryologyChongqing Medical University Chongqing China
- Laboratory of Stem Cell and Tissue EngineeringChongqing Medical University Chongqing China
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine, Ministry of EducationChongqing Medical University Chongqing China
| | - Lin Jiang
- Department of Histology and EmbryologyChongqing Medical University Chongqing China
- Laboratory of Stem Cell and Tissue EngineeringChongqing Medical University Chongqing China
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine, Ministry of EducationChongqing Medical University Chongqing China
| | - Lei Zhang
- Department of Histology and EmbryologyChongqing Medical University Chongqing China
- Laboratory of Stem Cell and Tissue EngineeringChongqing Medical University Chongqing China
| | - Jin‐hua Fan
- Department of Histology and EmbryologyChongqing Medical University Chongqing China
- Laboratory of Stem Cell and Tissue EngineeringChongqing Medical University Chongqing China
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine, Ministry of EducationChongqing Medical University Chongqing China
| | - Yong‐xin Wu
- Department of Histology and EmbryologyChongqing Medical University Chongqing China
- Laboratory of Stem Cell and Tissue EngineeringChongqing Medical University Chongqing China
- Department of Laboratory Medicine, Key Laboratory of Diagnostic Medicine, Ministry of EducationChongqing Medical University Chongqing China
| | - Xiao‐yun Dou
- Institute of Life SciencesChongqing Medical University Chongqing China
| | - Yong Tang
- Department of Histology and EmbryologyChongqing Medical University Chongqing China
- Laboratory of Stem Cell and Tissue EngineeringChongqing Medical University Chongqing China
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Farfán-García ED, Márquez-Gómez R, Barrón-González M, Pérez-Capistran T, Rosales-Hernández MC, Pinto-Almazán R, Soriano-Ursúa MA. Monoamines and their Derivatives on GPCRs: Potential Therapy for Alzheimer's Disease. Curr Alzheimer Res 2019; 16:871-894. [PMID: 30963972 DOI: 10.2174/1570159x17666190409144558] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/26/2018] [Revised: 03/18/2019] [Accepted: 04/01/2019] [Indexed: 02/07/2023]
Abstract
Albeit cholinergic depletion remains the key event in Alzheimer's Disease (AD), recent information describes stronger links between monoamines (trace amines, catecholamines, histamine, serotonin, and melatonin) and AD than those known in the past century. Therefore, new drug design strategies focus efforts to translate the scope on these topics and to offer new drugs which can be applied as therapeutic tools in AD. In the present work, we reviewed the state-of-art regarding genetic, neuropathology and neurochemistry of AD involving monoamine systems. Then, we compiled the effects of monoamines found in the brain of mammals as well as the reported effects of their derivatives and some structure-activity relationships. Recent derivatives have triggered exciting effects and pharmacokinetic properties in both murine models and humans. In some cases, the mechanism of action is clear, essentially through the interaction on G-protein-coupled receptors as revised in this manuscript. Additional mechanisms are inhibition of enzymes for their biotransformation, regulation of free-radicals in the central nervous system and others for the effects on Tau phosphorylation or amyloid-beta accumulation. All these data make the monoamines and their derivatives attractive potential elements for AD therapy.
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Affiliation(s)
- Eunice D Farfán-García
- Departamento de Fisiologia y Bioquimica. Seccion de Estudios de Posgrado e Investigacion, Escuela Superior de Medicina, Instituto Politecnico Nacional, Plan de San Luis y Diaz Miron s/n, 11340, Mexico City, Mexico
| | - Ricardo Márquez-Gómez
- MRC Anatomical Neuropharmacology Unit, Department of Pharmacology, University of Oxford, OX1 3TH, Oxford, United Kingdom
| | - Mónica Barrón-González
- Departamento de Fisiologia y Bioquimica. Seccion de Estudios de Posgrado e Investigacion, Escuela Superior de Medicina, Instituto Politecnico Nacional, Plan de San Luis y Diaz Miron s/n, 11340, Mexico City, Mexico
| | - Teresa Pérez-Capistran
- Departamento de Fisiologia y Bioquimica. Seccion de Estudios de Posgrado e Investigacion, Escuela Superior de Medicina, Instituto Politecnico Nacional, Plan de San Luis y Diaz Miron s/n, 11340, Mexico City, Mexico
| | - Martha C Rosales-Hernández
- Laboratorio de Biofisica y Biocatalisis, Seccion de Estudios de Posgrado e Investigacion Escuela Superior de Medicina, Instituto Politecnico Nacional, Plan de San Luis y Diaz Miron s/n, 11340, Mexico City, Mexico
| | - Rodolfo Pinto-Almazán
- Unidad de Investigacion Hospital Regional de Alta Especialidad Ixtapaluca, Carretera Federal Mexico-Puebla km 34.5, C.P. 56530. Ixtapaluca, State of Mexico, Mexico
| | - Marvin A Soriano-Ursúa
- Departamento de Fisiologia y Bioquimica. Seccion de Estudios de Posgrado e Investigacion, Escuela Superior de Medicina, Instituto Politecnico Nacional, Plan de San Luis y Diaz Miron s/n, 11340, Mexico City, Mexico
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22
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Hassan M, Abbas Q, Seo SY, Shahzadi S, Ashwal HA, Zaki N, Iqbal Z, Moustafa AA. Computational modeling and biomarker studies of pharmacological treatment of Alzheimer's disease (Review). Mol Med Rep 2018; 18:639-655. [PMID: 29845262 PMCID: PMC6059694 DOI: 10.3892/mmr.2018.9044] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/08/2017] [Accepted: 07/05/2017] [Indexed: 12/31/2022] Open
Abstract
Alzheimer's disease (AD) is a complex and multifactorial disease. In order to understand the genetic influence in the progression of AD, and to identify novel pharmaceutical agents and their associated targets, the present study discusses computational modeling and biomarker evaluation approaches. Based on mechanistic signaling pathway approaches, various computational models, including biochemical and morphological models, are discussed to explore the strategies that may be used to target AD treatment. Different biomarkers are interpreted on the basis of morphological and functional features of amyloid β plaques and unstable microtubule‑associated tau protein, which is involved in neurodegeneration. Furthermore, imaging and cerebrospinal fluids are also considered to be key methods in the identification of novel markers for AD. In conclusion, the present study reviews various biochemical and morphological computational models and biomarkers to interpret novel targets and agonists for the treatment of AD. This review also highlights several therapeutic targets and their associated signaling pathways in AD, which may have potential to be used in the development of novel pharmacological agents for the treatment of patients with AD. Computational modeling approaches may aid the quest for the development of AD treatments with enhanced therapeutic efficacy and reduced toxicity.
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Affiliation(s)
- Mubashir Hassan
- Department of Biology, College of Natural Sciences, Kongju National University, Gongju, Chungcheongnam 32588, Republic of Korea
- Institute of Molecular Science and Bioinformatics, Dyal Singh Trust Library, Lahore 54000, Pakistan
| | - Qamar Abbas
- Department of Physiology, University of Sindh, Jamshoro 76080, Pakistan
| | - Sung-Yum Seo
- Department of Biology, College of Natural Sciences, Kongju National University, Gongju, Chungcheongnam 32588, Republic of Korea
| | - Saba Shahzadi
- Institute of Molecular Science and Bioinformatics, Dyal Singh Trust Library, Lahore 54000, Pakistan
- Department of Bioinformatics, Virtual University Davis Road Campus, Lahore 54000, Pakistan
| | - Hany Al Ashwal
- College of Information Technology, United Arab Emirates University, Al-Ain 15551, United Arab Emirates
| | - Nazar Zaki
- College of Information Technology, United Arab Emirates University, Al-Ain 15551, United Arab Emirates
| | - Zeeshan Iqbal
- Institute of Molecular Science and Bioinformatics, Dyal Singh Trust Library, Lahore 54000, Pakistan
| | - Ahmed A. Moustafa
- School of Social Sciences and Psychology, Western Sydney University, Sydney, NSW 2751, Australia
- MARCS Institute for Brain, Behavior and Development, Western Sydney University, Sydney, NSW 2751, Australia
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23
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Quartey MO, Nyarko JNK, Pennington PR, Heistad RM, Klassen PC, Baker GB, Mousseau DD. Alzheimer Disease and Selected Risk Factors Disrupt a Co-regulation of Monoamine Oxidase-A/B in the Hippocampus, but Not in the Cortex. Front Neurosci 2018; 12:419. [PMID: 29997470 PMCID: PMC6029266 DOI: 10.3389/fnins.2018.00419] [Citation(s) in RCA: 31] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2018] [Accepted: 06/01/2018] [Indexed: 01/09/2023] Open
Abstract
Monoamine oxidase-A (MAO-A) and MAO-B have both been implicated in the pathology of Alzheimer disease (AD). We examined 60 autopsied control and AD donor brain samples to determine how well MAO function aligned with two major risk factors for AD, namely sex and APOE ε4 status. MAO-A activity was increased in AD cortical, but not hippocampal, samples. In contrast, MAO-B activity was increased in both regions (with a strong input from female donors) whether sample means were compared based on: (a) diagnosis alone; (b) diagnosis-by-APOE ε4 status (i.e., carriers vs. non-carriers of the ε4 allele); or (c) APOE ε4 status alone (i.e., ignoring ‘diagnosis’ as a variable). Sample means strictly based on the donor’s sex did not reveal any difference in either MAO-A or MAO-B activity. Unexpectedly, we found that cortical MAO-A and MAO-B activities were highly correlated in both males and females (if focussing strictly on the donor’s sex), while in the hippocampus, any correlation was lost in female samples. Stratifying for sex-by-APOE ε4 status revealed a strong correlation between cortical MAO-A and MAO-B activities in both non-carriers and carriers of the allele, but any correlation in hippocampal samples was lost in carriers of the allele. A diagnosis of AD disrupted the correlation between MAO-A and MAO-B activities in the hippocampus, but not the cortex. We observed a novel region-dependent co-regulation of MAO-A and MAO-B mRNAs (but not proteins), while a lack of correlation between MAO activities and the respective proteins corroborated previous reports. Overexpression of human APOE4 increased MAO activity (but not mRNA/protein) in C6 and in HT-22 cell cultures. We identified a novel co-regulation of MAO-A and MAO-B activities that is spared from any influence of risk factors for AD or AD itself in the cortex, but vulnerable to these same factors in the hippocampus. Sex- and region-dependent abilities to buffer influences on brain MAO activities could have significant bearing on ambiguous outcomes when monoaminergic systems are targeted in clinical populations.
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Affiliation(s)
- Maa O Quartey
- Cell Signalling Laboratory, Department of Psychiatry, University of Saskatchewan, Saskatoon, SK, Canada
| | - Jennifer N K Nyarko
- Cell Signalling Laboratory, Department of Psychiatry, University of Saskatchewan, Saskatoon, SK, Canada
| | - Paul R Pennington
- Cell Signalling Laboratory, Department of Psychiatry, University of Saskatchewan, Saskatoon, SK, Canada
| | - Ryan M Heistad
- Cell Signalling Laboratory, Department of Psychiatry, University of Saskatchewan, Saskatoon, SK, Canada
| | - Paula C Klassen
- The Pharmacology-Physiology Honours Program, University of Saskatchewan, Saskatoon, SK, Canada
| | - Glen B Baker
- Neurochemical Research Unit, Department of Psychiatry, University of Alberta, Edmonton, AB, Canada
| | - Darrell D Mousseau
- Cell Signalling Laboratory, Department of Psychiatry, University of Saskatchewan, Saskatoon, SK, Canada.,The Pharmacology-Physiology Honours Program, University of Saskatchewan, Saskatoon, SK, Canada
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24
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Vakalopoulos C. Alzheimer's Disease: The Alternative Serotonergic Hypothesis of Cognitive Decline. J Alzheimers Dis 2018; 60:859-866. [PMID: 28984594 DOI: 10.3233/jad-170364] [Citation(s) in RCA: 21] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
The pathognomonic feature of Alzheimer's disease is a loss of declarative memory. This has generally been attributed to early involvement of medial temporal lobe structures with neurofibrillary tangles and loss of neurons in the entorhinal cortex. However, there has been a re-emerging emphasis on the causal role of brainstem monoaminergic nuclei as involvement of the cholinergic basal forebrain loses prominence. The rejection of this latter theory of cognitive decline is related to inconsistencies in time course and modest effects of treatment using cholinergic agents. The amyloid hypothesis of cortical dysfunction is also losing favor as current trials of plaque dissolution are proving again disappointing. Recent pre-clinical studies on APP/PS1 (familial Alzheimer's disease) transgenic mouse models using serotonergic receptor modulating agents, demonstrate clear neuroprotective effects. The involvement of midbrain raphe in the earliest stages of dementia requires a reassessment of relevant pathophysiology beyond behavioral and affective dimensions. Indeed, a theory of serotonergic modulation of explicit memory formation by direct enhancement of synaptic strength could change the view of the role of these nuclei in AD and lead to more effective treatments.
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25
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Tajeddinn W, Fereshtehnejad SM, Seed Ahmed M, Yoshitake T, Kehr J, Shahnaz T, Milovanovic M, Behbahani H, Höglund K, Winblad B, Cedazo-Minguez A, Jelic V, Järemo P, Aarsland D. Association of Platelet Serotonin Levels in Alzheimer's Disease with Clinical and Cerebrospinal Fluid Markers. J Alzheimers Dis 2018; 53:621-30. [PMID: 27163811 DOI: 10.3233/jad-160022] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
INTRODUCTION Serotonin (5-HT) is involved in the pathology of Alzheimer's disease (AD). OBJECTIVE We aimed to measure 5-HT level in platelets in AD and explore its association with cerebrospinal fluid (CSF), AD biomarkers (amyloid-β 1-42 (Aβ42), total tau (t-tau), and phosphorylated tau (p-tau)), and clinical symptoms. METHODS 15 patients with AD and 20 patients with subjective cognitive impairment (SCI) were included. 5-HT metabolites were measured, in a specific fraction, using high performance liquid chromatography with electrochemical detection (HPLC-ECD). RESULTS Significantly lower 5-HT concentrations were observed in AD patients compared to SCI patients both after normalization against total protein (p = 0.008) or platelet count (p = 0.019). SCI patients with lower 5-HT level have higher AD CSF biomarkers, total tau (p = 0.026) and tau/Aβ42 ratio (p = 0.001), compared to those with high 5-HT levels. CONCLUSION AD patients have reduced platelet 5-HT levels. In SCI, lower 5-HT content was associated with a higher AD-CSF biomarker burden.
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Affiliation(s)
- Walid Tajeddinn
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden
| | - Seyed-Mohammad Fereshtehnejad
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden
| | - Mohammed Seed Ahmed
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden.,King's College London, Wolfson Centre for Age Related-Diseases, London, UK.,Department of Physiology, Faculty of Medicine, University of Khartoum, Khartoum, Sudan
| | - Takashi Yoshitake
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Jan Kehr
- Department of Physiology and Pharmacology, Karolinska Institutet, Stockholm, Sweden
| | - Tasmin Shahnaz
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden.,Department of Internal Medicine, the Vrinnevi Hospital, Norrköping, Sweden
| | - Micha Milovanovic
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden.,Department of Internal Medicine, the Vrinnevi Hospital, Norrköping, Sweden
| | - Homira Behbahani
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden
| | - Kina Höglund
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden.,Institute of Neuroscience and Physiology, Sahlgrenska Academy, Gothenburg University, Gothenburg, Sweden
| | - Bengt Winblad
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden
| | - Angel Cedazo-Minguez
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden
| | - Vesna Jelic
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden
| | - Petter Järemo
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden.,Department of Internal Medicine, the Vrinnevi Hospital, Norrköping, Sweden
| | - Dag Aarsland
- Department of Neurobiology, Care Sciences and Society, Center for Alzheimer Research, Division for Neurogeriatrics, Karolinska Institutet, Novum, Huddinge, Stockholm, Sweden.,Centre for Age-Related Medicine, Stavanger University Hospital, Stavanger, Norway.,Department of Neurology, Akershus University Hospital, Oslo, Norway
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de Jong IE, Mørk A. Antagonism of the 5-HT 6 receptor – Preclinical rationale for the treatment of Alzheimer's disease. Neuropharmacology 2017; 125:50-63. [DOI: 10.1016/j.neuropharm.2017.07.010] [Citation(s) in RCA: 48] [Impact Index Per Article: 6.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/19/2017] [Revised: 06/30/2017] [Accepted: 07/11/2017] [Indexed: 11/29/2022]
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27
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Verdurand M, Zimmer L. Hippocampal 5-HT1A receptor expression changes in prodromal stages of Alzheimer's disease: Beneficial or deleterious? Neuropharmacology 2017. [DOI: 10.1016/j.neuropharm.2017.06.021] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
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28
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Iatrou A, Kenis G, Rutten BPF, Lunnon K, van den Hove DLA. Epigenetic dysregulation of brainstem nuclei in the pathogenesis of Alzheimer's disease: looking in the correct place at the right time? Cell Mol Life Sci 2017; 74:509-523. [PMID: 27628303 PMCID: PMC5241349 DOI: 10.1007/s00018-016-2361-4] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/19/2016] [Revised: 08/15/2016] [Accepted: 09/07/2016] [Indexed: 12/20/2022]
Abstract
Even though the etiology of Alzheimer's disease (AD) remains unknown, it is suggested that an interplay among genetic, epigenetic and environmental factors is involved. An increasing body of evidence pinpoints that dysregulation in the epigenetic machinery plays a role in AD. Recent developments in genomic technologies have allowed for high throughput interrogation of the epigenome, and epigenome-wide association studies have already identified unique epigenetic signatures for AD in the cortex. Considerable evidence suggests that early dysregulation in the brainstem, more specifically in the raphe nuclei and the locus coeruleus, accounts for the most incipient, non-cognitive symptomatology, indicating a potential causal relationship with the pathogenesis of AD. Here we review the advancements in epigenomic technologies and their application to the AD research field, particularly with relevance to the brainstem. In this respect, we propose the assessment of epigenetic signatures in the brainstem as the cornerstone of interrogating causality in AD. Understanding how epigenetic dysregulation in the brainstem contributes to AD susceptibility could be of pivotal importance for understanding the etiology of the disease and for the development of novel diagnostic and therapeutic strategies.
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Affiliation(s)
- A Iatrou
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Universiteitssingel 50, 6200 MD, Maastricht, The Netherlands
| | - G Kenis
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Universiteitssingel 50, 6200 MD, Maastricht, The Netherlands
| | - B P F Rutten
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Universiteitssingel 50, 6200 MD, Maastricht, The Netherlands
| | - K Lunnon
- University of Exeter Medical School, RILD, University of Exeter, Barrack Road, Devon, UK
| | - D L A van den Hove
- Department of Psychiatry and Neuropsychology, School for Mental Health and Neuroscience (MHeNS), Maastricht University, Universiteitssingel 50, 6200 MD, Maastricht, The Netherlands.
- Laboratory of Translational Neuroscience, Department of Psychiatry, Psychosomatics and Psychotherapy, University of Wuerzburg, Fuechsleinstrasse 15, 97080, Würzburg, Germany.
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29
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Amat-Foraster M, Leiser SC, Herrik KF, Richard N, Agerskov C, Bundgaard C, Bastlund JF, de Jong IE. The 5-HT6 receptor antagonist idalopirdine potentiates the effects of donepezil on gamma oscillations in the frontal cortex of anesthetized and awake rats without affecting sleep-wake architecture. Neuropharmacology 2017; 113:45-59. [DOI: 10.1016/j.neuropharm.2016.09.017] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2016] [Revised: 08/14/2016] [Accepted: 09/15/2016] [Indexed: 01/21/2023]
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30
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Fernandez SP, Muzerelle A, Scotto-Lomassese S, Barik J, Gruart A, Delgado-García JM, Gaspar P. Constitutive and Acquired Serotonin Deficiency Alters Memory and Hippocampal Synaptic Plasticity. Neuropsychopharmacology 2017; 42:512-523. [PMID: 27461084 PMCID: PMC5399229 DOI: 10.1038/npp.2016.134] [Citation(s) in RCA: 64] [Impact Index Per Article: 9.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/29/2016] [Revised: 07/07/2016] [Accepted: 07/17/2016] [Indexed: 02/06/2023]
Abstract
Serotonin (5-HT) deficiency occurs in a number of brain disorders that affect cognitive function. However, a direct causal relationship between 5-HT hypo-transmission and memory and underlying mechanisms has not been established. We used mice with a constitutive depletion of 5-HT brain levels (Pet1KO mice) to analyze the contribution of 5-HT to different forms of learning and memory. Pet1KO mice exhibited a striking deficit in novel object recognition memory, a hippocampal-dependent task. No alterations were found in tasks for social recognition, procedural learning, or fear memory. Viral delivery of designer receptors exclusively activated by designer drugs was used to selectively silence the activity of 5-HT neurons in the raphe. Inhibition of 5-HT neurons in the median raphe, but not the dorsal raphe, was sufficient to impair object recognition in adult mice. In vivo electrophysiology in behaving mice showed that long-term potentiation in the hippocampus of 5-HT-deficient mice was altered, and administration of the 5-HT1A agonist 8-OHDPAT rescued the memory deficits. Our data suggest that hyposerotonergia selectively affects declarative hippocampal-dependent memory. Serotonergic projections from the median raphe are necessary to regulate object memory and hippocampal synaptic plasticity processes, through an inhibitory control mediated by 5-HT1A receptors.
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Affiliation(s)
- Sebastian P Fernandez
- Institut du Fer à Moulin, Paris, France,INSERM, UMRS-839, Paris, France,University Pierre and Marie Curie, Paris, France,Institut de Pharmacologie Moléculaire et Cellulaire (IPMC), Université Côte d'Azur, CNRS UMR 7275, Valbonne, 0656, France, Tel: +33 4 93 95 34 41, Fax: +33 4 93 95 34 08, E-mail:
| | - Aude Muzerelle
- Institut du Fer à Moulin, Paris, France,INSERM, UMRS-839, Paris, France,University Pierre and Marie Curie, Paris, France
| | - Sophie Scotto-Lomassese
- Institut du Fer à Moulin, Paris, France,INSERM, UMRS-839, Paris, France,University Pierre and Marie Curie, Paris, France
| | - Jacques Barik
- Université Côte d'Azur, CNRS, IPMC, Valbonne, France
| | - Agnès Gruart
- Division of Neurosciences, Pablo de Olavide University, Seville, Spain
| | | | - Patricia Gaspar
- Institut du Fer à Moulin, Paris, France,INSERM, UMRS-839, Paris, France,University Pierre and Marie Curie, Paris, France
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31
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Jones HE, Joshi A, Shenkin S, Mead GE. The effect of treatment with selective serotonin reuptake inhibitors in comparison to placebo in the progression of dementia: a systematic review and meta-analysis. Age Ageing 2016; 45:448-56. [PMID: 27055878 DOI: 10.1093/ageing/afw053] [Citation(s) in RCA: 23] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/15/2015] [Accepted: 02/08/2016] [Indexed: 12/24/2022] Open
Abstract
BACKGROUND selective serotonin reuptake inhibitors (SSRIs) may affect the neurodegenerative process of dementia, enhancing cognition. This systematic review aims to determine whether SSRIs influence cognitive performance, mood and function in people with any type of dementia. METHOD randomised placebo-controlled studies of SSRIs in people with dementia, which recorded cognitive outcomes, were identified in ALOIS (ALzheimer's and cOgnitive Improvement Studies register) in April 2013 and updated in January 2015. Data were extracted on cognition, agitation, mood, activities of daily living (ADLs) and adverse events. End of treatment statistics were calculated. RESULTS twelve studies met inclusion criteria (1,174 participants), of which seven studies (710 participants) provided data for meta-analysis on cognition. There was no difference in MMSE score at end of treatment; mean difference (MD) was 0.28 (95% CI -0.83 to 1.39) (six studies, 470 participants). For change in MMSE scores, there was a small improvement; MD was 0.53 (95%CI -0.07 to 1.14) (three studies, 352 participants). The remaining studies showed no improvement in cognition. There was no statistically significant benefit of SSRIs on mood (four studies, 317 participants); standard mean difference (SMD) -0.10 (95% CI -0.39 to 0.2), agitation (three studies, 189 participants); SMD -0.01(95% CI -0.86 to 0.83), or ADLs at end of treatment (four studies, 336 participants); SMD -0.15(95% CI -0.45 to 0.15). There was no difference in mortality between the two groups. Study quality was mixed with concerns over incomplete data. CONCLUSION a small number of relatively low-powered studies showed no benefit or harm from SSRIs in terms of cognition, mood, agitation or ADLs. Large, methodologically robust studies are needed.
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Affiliation(s)
| | | | - Susan Shenkin
- Department of Geriatric Medicine, University of Edinburgh, Edinburgh, UK Centre for Cognitive Ageing and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Gillian E Mead
- Department of Geriatric Medicine, University of Edinburgh, Edinburgh, UK Centre for Cognitive Ageing and Cognitive Epidemiology, Department of Psychology, University of Edinburgh, Edinburgh, UK
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Theofilas P, Dunlop S, Heinsen H, Grinberg LT. Turning on the Light Within: Subcortical Nuclei of the Isodentritic Core and their Role in Alzheimer's Disease Pathogenesis. J Alzheimers Dis 2016; 46:17-34. [PMID: 25720408 DOI: 10.3233/jad-142682] [Citation(s) in RCA: 70] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/16/2023]
Abstract
Pharmacological interventions in Alzheimer's disease (AD) are likely to be more efficacious if administered early in the course of the disease, foregoing the spread of irreversible changes in the brain. Research findings underline an early vulnerability of the isodendritic core (IC) network to AD neurofibrillary lesions. The IC constitutes a phylogenetically conserved subcortical system including the locus coeruleus in pons, dorsal raphe nucleus, and substantia nigra in the midbrain, and nucleus basalis of Meynert in basal forebrain. Through their ascending projections to the cortex, the IC neurons regulate homeostasis and behavior by synthesizing aminergic and cholinergic neurotransmitters. Here we reviewed the evidence demonstrating that neurons of the IC system show neurofibrillary tangles in the earliest stages of AD, prior to cortical pathology, and how this involvement may explain pre-amnestic symptoms, including depression, agitation, and sleep disturbances in AD patients. In fact, clinical and animal studies show a significant reduction of AD cognitive and behavioral symptoms following replenishment of neurotransmitters associated with the IC network. Therefore, the IC network represents a unique candidate for viable therapeutic intervention and should become a high priority for research in AD.
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Affiliation(s)
- Panos Theofilas
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Sara Dunlop
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA
| | - Helmut Heinsen
- Department of Pathology, University of Sao Paulo Medical School, Sao Paulo, Brazil.,Department of Psychiatrics, University of Wuerzburg, Germany
| | - Lea Tenenholz Grinberg
- Memory and Aging Center, Department of Neurology, University of California, San Francisco, San Francisco, CA, USA.,Department of Pathology, University of Sao Paulo Medical School, Sao Paulo, Brazil
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Tajeddinn W, Persson T, Maioli S, Calvo-Garrido J, Parrado-Fernandez C, Yoshitake T, Kehr J, Francis P, Winblad B, Höglund K, Cedazo-Minguez A, Aarsland D. 5-HT1B and other related serotonergic proteins are altered in APPswe mutation. Neurosci Lett 2015; 594:137-43. [DOI: 10.1016/j.neulet.2015.03.064] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2014] [Revised: 03/29/2015] [Accepted: 03/30/2015] [Indexed: 11/29/2022]
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Limited effects of an eIF2αS51A allele on neurological impairments in the 5xFAD mouse model of Alzheimer's disease. Neural Plast 2015; 2015:825157. [PMID: 25883808 PMCID: PMC4391319 DOI: 10.1155/2015/825157] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2014] [Revised: 02/15/2015] [Accepted: 02/23/2015] [Indexed: 02/02/2023] Open
Abstract
Alzheimer's disease (AD) has been associated with increased phosphorylation of the translation initiation factor 2α (eIF2α) at serine 51. Increased phosphorylation of eIF2α alters translational control and may thereby have adverse effects on synaptic plasticity, learning, and memory. To analyze if increased levels of p-eIF2α indeed promote AD-related neurocognitive impairments, we crossed 5xFAD transgenic mice with an eIF2αS51A knock-in line that expresses the nonphosphorylatable eIF2α variant eIF2αS51A. Behavioral assessment of the resulting mice revealed motor and cognitive deficits in 5xFAD mice that were, with the possible exception of locomotor hyperactivity, not restored by the eIF2αS51A allele. Telemetric intracranial EEG recordings revealed no measurable effects of the eIF2αS51A allele on 5xFAD-associated epileptic activity. Microarray-based transcriptome analyses showed clear transcriptional alterations in 5xFAD hippocampus that were not corrected by the eIF2αS51A allele. In contrast to prior studies, our immunoblot analyses did not reveal increased levels of p-eIF2α in the hippocampus of 5xFAD mice, suggesting that elevated p-eIF2α levels are not a universal feature of AD models. Collectively, our data indicate that 5xFAD-related pathologies do not necessarily require hyperphosphorylation of eIF2α to emerge; they also show that heterozygosity for the nonphosphorylatable eIF2αS51A allele has limited effects on 5xFAD-related disease manifestations.
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Prakash A, Kalra J, Mani V, Ramasamy K, Majeed ABA. Pharmacological approaches for Alzheimer’s disease: neurotransmitter as drug targets. Expert Rev Neurother 2014; 15:53-71. [DOI: 10.1586/14737175.2015.988709] [Citation(s) in RCA: 17] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
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36
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Kinetics of serotonin oxidation by heme–Aβ relevant to Alzheimer’s disease. J Biol Inorg Chem 2014; 19:1355-65. [DOI: 10.1007/s00775-014-1193-7] [Citation(s) in RCA: 19] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/23/2014] [Accepted: 09/04/2014] [Indexed: 01/11/2023]
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37
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Decreased platelet serotonin concentration in Alzheimer's disease with involuntary emotional expression disorder. Neurosci Lett 2014; 578:71-4. [DOI: 10.1016/j.neulet.2014.06.034] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/06/2014] [Revised: 05/18/2014] [Accepted: 06/13/2014] [Indexed: 11/19/2022]
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39
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Creese B, Ballard C, Jones E. Cognitive impairment in studies of 5HTTLPR and psychosis in Alzheimer's disease: a systematic review. Dement Geriatr Cogn Disord 2013; 35:155-64. [PMID: 23392273 DOI: 10.1159/000346733] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 12/18/2012] [Indexed: 01/12/2023] Open
Abstract
BACKGROUND/AIMS Cognitive impairment is a well-established correlate of psychotic symptoms in Alzheimer's disease (AD-P). We review whether this relationship has confounded previous genetic association studies of 5HTTLPR and AD-P. METHODS We reviewed all studies on 5HTTLPR and conducted a semi-quantitative analysis. RESULTS Three out of 4 studies with low MMSE reported a significant association, while 1 out of 4 with high MMSE reported a significant association. CONCLUSIONS Variation in cognitive impairment in past studies has contributed to the inconsistency in findings. The findings presented here bring a greater clarity to our understanding of the role of 5HTTLPR in AD-P.
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Affiliation(s)
- Byron Creese
- Wolfson Centre for Age-Related Diseases, King's College London, London, UK
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40
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Rodríguez JJ, Noristani HN, Verkhratsky A. The serotonergic system in ageing and Alzheimer's disease. Prog Neurobiol 2012; 99:15-41. [DOI: 10.1016/j.pneurobio.2012.06.010] [Citation(s) in RCA: 142] [Impact Index Per Article: 11.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2011] [Revised: 05/24/2012] [Accepted: 06/22/2012] [Indexed: 01/11/2023]
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41
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Xu Y, Yan J, Zhou P, Li J, Gao H, Xia Y, Wang Q. Neurotransmitter receptors and cognitive dysfunction in Alzheimer's disease and Parkinson's disease. Prog Neurobiol 2012; 97:1-13. [PMID: 22387368 DOI: 10.1016/j.pneurobio.2012.02.002] [Citation(s) in RCA: 195] [Impact Index Per Article: 16.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2011] [Revised: 01/06/2012] [Accepted: 02/15/2012] [Indexed: 12/12/2022]
Abstract
Cognitive dysfunction is one of the most typical characteristics in various neurodegenerative diseases such as Alzheimer's disease and Parkinson's disease (advanced stage). Although several mechanisms like neuronal apoptosis and inflammatory responses have been recognized to be involved in the pathogenesis of cognitive dysfunction in these diseases, recent studies on neurodegeneration and cognitive dysfunction have demonstrated a significant impact of receptor modulation on cognitive changes. The pathological alterations in various receptors appear to contribute to cognitive impairment and/or deterioration with correlation to diversified mechanisms. This article recapitulates the present understandings and concepts underlying the modulation of different receptors in human beings and various experimental models of Alzheimer's disease and Parkinson's disease as well as a conceptual update on the underlying mechanisms. Specific roles of serotonin, adrenaline, acetylcholine, dopamine receptors, and N-methyl-D-aspartate receptors in Alzheimer's disease and Parkinson's disease will be interactively discussed. Complex mechanisms involved in their signaling pathways in the cognitive dysfunction associated with the neurodegenerative diseases will also be addressed. Substantial evidence has suggested that those receptors are crucial neuroregulators contributing to cognitive pathology and complicated correlations exist between those receptors and the expression of cognitive capacities. The pathological alterations in the receptors would, therefore, contribute to cognitive impairments and/or deterioration in Alzheimer's disease and Parkinson's disease. Future research may shed light on new clues for the treatment of cognitive dysfunction in neurodegenerative diseases by targeting specific alterations in these receptors and their signal transduction pathways in the frontal-striatal, fronto-striato-thalamic, and mesolimbic circuitries.
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Affiliation(s)
- Yunqi Xu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, Guangdong 510630, PR China
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Differential involvement of hippocampal serotonin1A receptors and re-uptake sites in non-cognitive behaviors of Alzheimer's disease. Psychopharmacology (Berl) 2011; 213:431-9. [PMID: 20625884 DOI: 10.1007/s00213-010-1936-2] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 04/21/2010] [Accepted: 06/23/2010] [Indexed: 10/19/2022]
Abstract
RATIONALE Previous studies have shown extensive serotonergic deficits in the hippocampus of Alzheimer's disease (AD) patients. However, it is unclear whether such deficits play a role in non-cognitive, neuropsychiatric behaviors that occur frequently in AD and cause significant caregiver distress. OBJECTIVES In this study, we aimed to correlate serotonergic markers in the AD hippocampus with neuropsychiatric behaviors. METHODS Using postmortem hippocampal homogenates from aged controls as well as a cohort of longitudinally assessed AD patients, measurements of 5-HT(1A) receptors, 5-HT(2A) receptors, and serotonin re-uptake (5-HTT) sites were performed by binding with (3)H-labeled 8-OH-DPAT, ketanserin, and citalopram, respectively. RESULTS Alterations of 5-HT(1A) receptors and 5-HTT were found to be differentially involved in neuropsychiatric behaviors, with loss of 5-HT(1A) receptors specifically correlated with depressive symptoms, while 5-HTT sites were preserved or up-regulated in patients with aggressive behaviors. CONCLUSIONS Our data suggest that neuropsychiatric behaviors in AD share certain neurochemical features with psychiatric disorders like major depression and that serotonergic drugs used in psychiatric disorders may also be efficacious against behavioral symptoms in AD.
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Signalling pathways associated with 5-HT6 receptors: relevance for cognitive effects. Int J Neuropsychopharmacol 2010; 13:775-84. [PMID: 19737440 DOI: 10.1017/s146114570999054x] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
A growing body of evidence supports the use of serotonin 5-HT6 receptor antagonists as a promising mechanism for treating cognitive dysfunction. We evaluated 5-HT6 receptor expression and associated biochemical mechanisms in the hippocampus of rats that had been trained in the Morris water maze (MWM), a spatial learning task. Training in the MWM induces a down-regulation of 5-HT6 receptor protein and mRNA receptor expression. The learning procedure or the administration of the selective 5-HT6 receptor antagonist SB-271046 induced an increase in pCREB1 levels while CREB2 levels were significantly reduced. However, although SB-271046 was able to improve retention in the MWM, no further changes in pCREB1 or CREB2 levels were found to be associated with the presence of the 5-HT6 receptor antagonist during the learning procedure. The MWM procedure significantly increased pERK1/2 levels and interestingly, further increases were seen when treating with SB-271046 during the MWM. These results suggest that, in the hippocampus, biochemical pathways associated with pERK1/2 expression, and not with the CREB family of transcription factors, seem to be related to the cognitive-enhancing properties of 5-HT6 receptor antagonists.
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Noristani HN, Olabarria M, Verkhratsky A, Rodríguez JJ. Serotonin fibre sprouting and increase in serotonin transporter immunoreactivity in the CA1 area of hippocampus in a triple transgenic mouse model of Alzheimer's disease. Eur J Neurosci 2010; 32:71-9. [PMID: 20576032 DOI: 10.1111/j.1460-9568.2010.07274.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that deteriorates cognitive functions and associated brain regions such as the hippocampus, being the primary cause of dementia. Serotonin (5-HT) is widely present in the hippocampus, being an important neurotransmitter involved in learning and memory. Although recent evidence suggests alterations in 5-HT neurotransmission in AD, it is not clear how hippocampal 5-HT innervation is modified. Here, we studied hippocampal 5-HT innervation by analysing: (i) the expression, density and distribution of 5-HT transporter (SERT)-immunoreactive fibres; (ii) the specific morphological characteristics of serotonergic fibres and their relation to amyloid plaques; and (iii) the total number of 5-HT neurons within the raphe nuclei in triple transgenic mouse model of AD. We used quantitative light microscopy immunohistochemistry comparing transgenic and non-transgenic animals of different ages (3, 6, 9, 12 and 18 months). The transgenic animals showed a significant increase in SERT fibres in the hippocampus in a subfield-, strata- and age-specific manner. The increase in SERT fibres was specific to the CA1 stratum lacunosum-moleculare. An increase in SERT fibres in transgenic animals was observed at 3 months (by 61%) and at 18 months (by 74%). No changes, however, were found in the total number of raphe 5-HT neurons at any age. Our results indicate that triple transgenic mice display changes in the expression of SERT and increased SERT fibres sprouting, which may account for imbalanced serotonergic neurotransmission associated with (or linked to) AD cognitive impairment.
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Affiliation(s)
- H N Noristani
- Faculty of Life Sciences, The University of Manchester, Manchester, UK
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Keowkase R, Aboukhatwa M, Luo Y. Fluoxetine protects against amyloid-beta toxicity, in part via daf-16 mediated cell signaling pathway, in Caenorhabditis elegans. Neuropharmacology 2010; 59:358-65. [PMID: 20420844 DOI: 10.1016/j.neuropharm.2010.04.008] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2010] [Revised: 03/26/2010] [Accepted: 04/07/2010] [Indexed: 12/22/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder and is the most common form of dementia in elderly people. The accumulation of amyloid beta (Abeta) is one of the histopathological hallmarks of AD. Abeta is aggregated to form oligomers which are toxic to neurons and are critical to the onset and progression of AD. In a Caenorhabditis elegans (C. elegans) model of AD, human Abeta is expressed intracellularly in the body wall muscle. The expression and subsequent aggregation of Abeta in the muscle lead to progressive paralysis. Although the mechanism of action is unknown, antidepressants have been used with FDA approved drugs for dementia in AD and have been shown to enhance cognitive function in human and in animal models of AD. We found that the antidepressant fluoxetine, a selective serotonin reuptake inhibitor, significantly delayed Abeta-induced paralysis in the C. elegans model of Abeta toxicity by reducing Abeta oligomers. Our results showed that insulin signaling and DAF-16/FOXO transcription factors were required for fluoxetine-mediated delayed paralysis. We also found that fluoxetine increased thermal stress resistance and extended life span. These findings suggests that fluoxetine may have benefit for the treatment of AD by the reduction of proteotoxicity.
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Affiliation(s)
- Roongpetch Keowkase
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, Baltimore, MD 21201, USA
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Aboukhatwa M, Dosanjh L, Luo Y. Antidepressants are a rational complementary therapy for the treatment of Alzheimer's disease. Mol Neurodegener 2010; 5:10. [PMID: 20226030 PMCID: PMC2845130 DOI: 10.1186/1750-1326-5-10] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/16/2009] [Accepted: 03/12/2010] [Indexed: 12/17/2022] Open
Abstract
There is a high prevalence rate (30-50%) of Alzheimer's disease (AD) and depression comorbidity. Depression can be a risk factor for the development of AD or it can be developed secondary to the neurodegenerative process. There are numerous documented diagnosis and treatment challenges for the patients who suffer comorbidity between these two diseases. Meta analysis studies have provided evidence for the safety and efficacy of antidepressants in treatment of depression in AD patients. Preclinical and clinical studies show the positive role of chronic administration of selective serotonin reuptake inhibitor (SSRI) antidepressants in hindering the progression of the AD and improving patient performance. A number of clinical studies suggest a beneficial role of combinatorial therapies that pair antidepressants with FDA approved AD drugs. Preclinical studies also demonstrate a favorable effect of natural antidepressants for AD patients. Based on the preclinical studies there are a number of plausible antidepressants effects that may modulate the progression of AD. These effects include an increase in neurogenesis, improvement in learning and memory, elevation in the levels of neurotrophic factors and pCREB and a reduction of amyloid peptide burden. Based on this preclinical and clinical evidence, antidepressants represent a rational complimentary strategy for the treatment of AD patients with depression comorbidity.
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Affiliation(s)
- Marwa Aboukhatwa
- Department of Pharmaceutical Sciences, School of Pharmacy, University of Maryland, 20 N Pine St, Baltimore, MD 21201, USA.
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Tsang SW, Keene J, Hope T, Spence I, Francis PT, Wong PTH, Chen CP, Lai MK. A serotoninergic basis for hyperphagic eating changes in Alzheimer's disease. J Neurol Sci 2009; 288:151-5. [PMID: 19818455 DOI: 10.1016/j.jns.2009.08.066] [Citation(s) in RCA: 26] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/22/2009] [Revised: 08/26/2009] [Accepted: 08/28/2009] [Indexed: 10/20/2022]
Abstract
Hyperphagia and associated eating changes occur frequently in Alzheimer's disease (AD) and lead to considerable morbidity. However, the neurochemical basis for these neuropsychiatric behaviours is at present unclear. In this study, we measured serotonin transporters, 5-HT(1A), 5-HT(2A), and 5-HT(4) receptors using radioligand binding assays in the postmortem temporal cortex of a cohort of controls and AD patients longitudinally assessed for hyperphagia. We found significant decreases in 5-HT(4) receptor densities in the hyperphagic, but not normophagic, AD group. Our data suggest that 5-HT(4) receptor deficits may be a specific neurochemical correlate of hyperphagia, and point to the potential pharmacotherapeutic utility of 5-HT(4) agonists for these behaviours in AD.
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Affiliation(s)
- Shirley W Tsang
- Dementia Research Laboratory, Department of Clinical Research, Singapore General Hospital, Singapore
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Dutra LA, Pedroso JL, Felix EPV, Barsottini OGP. Venlafaxine induced-myoclonus in a patient with mixed dementia. ARQUIVOS DE NEURO-PSIQUIATRIA 2008; 66:894-5. [DOI: 10.1590/s0004-282x2008000600025] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/25/2023]
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Loss of [3H]4-DAMP binding to muscarinic receptors in the orbitofrontal cortex of Alzheimer's disease patients with psychosis. Psychopharmacology (Berl) 2008; 198:251-9. [PMID: 18373228 DOI: 10.1007/s00213-008-1124-9] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/25/2007] [Accepted: 02/25/2008] [Indexed: 10/22/2022]
Abstract
RATIONALE Neuropsychiatric behaviours in Alzheimer's disease (AD) patients have been associated with neocortical alterations of presynaptic cholinergic and muscarinic M2 receptor markers. In contrast, it is unclear whether non-M2 muscarinic receptors have a role to play in AD behavioural symptoms. OBJECTIVES To correlate the alterations of neocortical postsynaptic muscarinic receptors with clinical features of AD. MATERIALS AND METHODS [(3)H]4-DAMP were used in binding assays with lysates of Chinese hamster ovary (CHO) cells stably transfected with M1-M5 receptors. [(3)H]4-DAMP was further used to measure muscarinic receptors in the postmortem orbitofrontal cortex of aged controls and AD patients longitudinally assessed for cognitive decline and behavioural symptoms. RESULTS [(3)H]4-DAMP binds to human postmortem brain homogenates and M1-, M3-, M4- and M5-transfected CHO lysates with subnanomolar affinity. Compared to the controls, the [(3)H]4-DAMP binding density is reduced only in AD patients with significant psychotic symptoms. The association between reduced [(3)H]4-DAMP binding and psychosis is independent of the effects of dementia severity or neurofibrillary tangle burden. CONCLUSIONS This study suggests that the loss of non-M2 muscarinic receptors in the orbitofrontal cortex may be a neurochemical substrate of psychosis in AD and provides a rationale for further development of muscarinic receptor ligands in AD pharmacotherapy.
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Kenton L, Boon F, Cain DP. Combined but not individual administration of beta-adrenergic and serotonergic antagonists impairs water maze acquisition in the rat. Neuropsychopharmacology 2008; 33:1298-311. [PMID: 17653108 DOI: 10.1038/sj.npp.1301518] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
This study examined the effects of serotonergic depletion and beta-adrenergic antagonism on performance in both visible platform and hidden platform versions of the water maze task. Male Long-Evans rats received systemic injections of p-chlorophenylalanine (500 mg/kg x 2) to deplete serotonin, or propranolol (20 or 40 mg/kg) to antagonize beta-adrenergic receptors. Some rats received treatments in combination. To separate strategies learning from spatial learning, half of the rats underwent Morris' water maze strategies pretraining before drug administration and spatial training. Individual depletion of serotonin or antagonism of beta-adrenergic receptors caused few or no impairments in either naive or pretrained rats in either version of the task. In contrast, combined depletion of serotonin and antagonism of beta-adrenergic receptors impaired naive rats in the visible platform task and impaired both naive and strategies-pretrained rats in the hidden platform task, and also caused sensorimotor impairments. This is the first finding of a 'global' water maze task/sensorimotor impairment with combined administration of two agents that, at the high doses that were given individually, produced few or no impairments. The data imply that (1) serotonergic and beta-adrenergic systems may interact in a manner that is important for adaptive behavior; (2) impairments in these systems found in Alzheimer patients may be important for their cognitive and behavioral impairments; and (3) the approach used here can model aspects of the cognitive and behavioral impairments in Alzheimer disease.
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Affiliation(s)
- Laura Kenton
- Department of Psychology, University of Western Ontario, London, ON, Canada
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