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Azimzadeh M, Cheah PS, Ling KH. Brain insulin resistance in Down syndrome: Involvement of PI3K-Akt/mTOR axis in early-onset of Alzheimer's disease and its potential as a therapeutic target. Biochem Biophys Res Commun 2024; 733:150713. [PMID: 39307112 DOI: 10.1016/j.bbrc.2024.150713] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/12/2024] [Revised: 08/27/2024] [Accepted: 09/16/2024] [Indexed: 10/06/2024]
Abstract
Down syndrome (DS) is the most common genetic cause of intellectual impairment, characterised by an extra copy of chromosome 21. After the age of 40, DS individuals are highly susceptible to accelerated ageing and the development of early-onset Alzheimer-like neuropathology. In the context of DS, the brain presents a spectrum of neuropathological mechanisms and metabolic anomalies. These include heightened desensitisation of brain insulin and insulin-like growth factor-1 (IGF-1) reactions, compromised mitochondrial functionality, escalated oxidative stress, reduced autophagy, and the accumulation of amyloid beta and tau phosphorylation. These multifaceted factors intertwine to shape the intricate landscape of DS-related brain pathology. Altered brain insulin signalling is linked to Alzheimer's disease (AD). This disruption may stem from anomalies in the extracellular aspect (insulin receptor) or the intracellular facet, involving the inhibition of insulin receptor substrate 1 (IRS1). Both domains contribute to the intricate mechanism underlying this dysregulation. The PI3K-Akt/mammalian target of the rapamycin (mTOR) axis is a crucial intracellular element of the insulin signalling pathway that connects numerous physiological processes in the cell cycle. In age-related neurodegenerative disorders like AD, aberrant modulation of the PI3K-Akt signalling cascade is a key factor contributing to their onset. Aberrant and sustained hyperactivation of the PI3K/Akt-mTOR axis in the DS brain is implicated in early symptoms of AD development. Targeting the PI3K-Akt/mTOR pathway may help delay the onset of early-onset AD in individuals with DS, offering a potential way to slow disease progression and enhance their quality of life.
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Affiliation(s)
- Mansour Azimzadeh
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia
| | - Pike-See Cheah
- Department of Human Anatomy, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Malaysian Research Institute on Ageing (MyAgeing®), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
| | - King-Hwa Ling
- Department of Biomedical Sciences, Faculty of Medicine and Health Sciences, Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia; Malaysian Research Institute on Ageing (MyAgeing®), Universiti Putra Malaysia, 43400 UPM Serdang, Selangor, Malaysia.
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2
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Ongnok B, Prathumsap N, Chunchai T, Pantiya P, Arunsak B, Chattipakorn N, Chattipakorn SC. Nicotinic and Muscarinic Acetylcholine Receptor Agonists Counteract Cognitive Impairment in a Rat Model of Doxorubicin-Induced Chemobrain via Attenuation of Multiple Programmed Cell Death Pathways. Mol Neurobiol 2024; 61:8831-8850. [PMID: 38568417 DOI: 10.1007/s12035-024-04145-0] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/01/2023] [Accepted: 03/21/2024] [Indexed: 10/23/2024]
Abstract
Chemotherapy causes undesirable long-term neurological sequelae, chemotherapy-induced cognitive impairment (CICI), or chemobrain in cancer survivors. Activation of programmed cell death (PCD) has been proposed to implicate in the development and progression of chemobrain. Neuronal apoptosis has been extensively recognized in experimental models of chemobrain, but little is known about alternative forms of PCD in response to chemotherapy. Activation of acetylcholine receptors (AChRs) is emerging as a promising target in attenuating a wide variety of the neuronal death associated with neurodegeneration. Thus, this study aimed to investigate the therapeutic capacity of AChR agonists on cognitive function and molecular hallmarks of multiple PCD against chemotherapy neurotoxicity. To establish the chemobrain model, male Wistar rats were assigned to receive six doses of doxorubicin (DOX: 3 mg/kg) via intraperitoneal injection. The DOX-treated rats received either an a7nAChR agonist (PNU-282987: 3 mg/kg/day), mAChR agonists (bethanechol: 12 mg/kg/day), or the two as a combined treatment. DOX administration led to impaired cognitive function via neuroinflammation, glial activation, reduced synaptic/blood-brain barrier integrity, defective mitochondrial ROS-detoxifying capacity, and dynamic imbalance. DOX insult also mediated hyperphosphorylation of Tau and simultaneously induced various PCD, including apoptosis, necroptosis, and pyroptosis in the hippocampus. Concomitant treatment with either PNU-282987, bethanechol, or a combination of the two potently attenuated neuroinflammation, mitochondrial dyshomeostasis, and Tau hyperphosphorylation, thereby suppressing excessive apoptosis, necroptosis, and pyroptosis and improving cognitive function in DOX-treated rats. Our findings suggest that activation of AChRs using their agonists effectively protected against DOX-induced neuronal death and chemobrain.
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Affiliation(s)
- Benjamin Ongnok
- Neuroelectrophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
- Cardiac Electrophysiology Unit, Department of Physiology, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
| | - Nanthip Prathumsap
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
- Cardiac Electrophysiology Unit, Department of Physiology, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
| | - Titikorn Chunchai
- Neuroelectrophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
- Cardiac Electrophysiology Unit, Department of Physiology, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
| | - Patcharapong Pantiya
- Neuroelectrophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
- Cardiac Electrophysiology Unit, Department of Physiology, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
| | - Busarin Arunsak
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
- Cardiac Electrophysiology Unit, Department of Physiology, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
| | - Nipon Chattipakorn
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
- Cardiac Electrophysiology Unit, Department of Physiology, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand
| | - Siriporn C Chattipakorn
- Neuroelectrophysiology Unit, Cardiac Electrophysiology Research and Training Center, Faculty of Medicine, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand.
- Center of Excellence in Cardiac Electrophysiology Research, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand.
- Cardiac Electrophysiology Unit, Department of Physiology, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand.
- Department of Oral Biology and Diagnostic Sciences, Faculty of Dentistry, Chiang Mai University, Mueang Chiang Mai, 50200, Chiang Mai, Thailand.
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3
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Tong H, Capuano AW, Carmichael OT, Gwizdala KL, Bennett DA, Ahima RS, Arnold SE, Arvanitakis Z. Brain Insulin Signaling is Associated with Late-Life Cognitive Decline. Aging Dis 2024; 15:2205-2215. [PMID: 38029396 PMCID: PMC11346412 DOI: 10.14336/ad.2023.1117] [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: 09/07/2023] [Accepted: 11/17/2023] [Indexed: 12/01/2023] Open
Abstract
Type-2 diabetes is associated with an increased risk of dementia, and the underlying mechanism might involve abnormal insulin signaling in the brain. The objective of this study was to examine the association of postmortem brain insulin signaling with late-life cognitive decline. Among participants of Religious Orders Study, a community-based clinical-pathological cohort, 150 deceased and autopsied older individuals (75 with diabetes matched to 75 without by age at death, sex, and education) had postmortem brain insulin signaling measurements collected in the prefrontal cortex using ELISA and immunohistochemistry. By using adjusted linear mixed-effects models, we examined the association of postmortem brain insulin signaling with late-life cognitive function assessed longitudinally (mean follow-up duration = 9.4 years) using a battery of neuropsychological tests. We found that a higher level of serine/threonine-protein kinase (AKT) phosphorylation (pT308AKT1/total AKT1) was associated with a faster decline in global cognition (estimate = -0.023, p = 0.030), and three domains: episodic memory (estimate = -0.024, p = 0.032), working memory (estimate = -0.018, p = 0.012), and visuospatial abilities (estimate = -0.013, p = 0.027). The level of insulin receptor substrate-1 (IRS1) phosphorylation (pS307IRS1/total IRS1) was not associated with decline in global cognition or most cognitive domains, except for perceptual speed (estimate = 0.020, p = 0.020). The density of pS616IRS1-stained cells was not associated with decline in global cognition or any of the domains. In conclusion, these findings provide novel evidence for an association between brain insulin signaling and late-life cognitive decline. AKT phosphorylation is associated with a decline in global cognition and memory in particular, whereas IRS1 phosphorylation is associated with a decline in perceptual speed.
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Affiliation(s)
- Han Tong
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA.
| | - Ana W. Capuano
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA.
| | | | | | - David A. Bennett
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA.
| | - Rexford S. Ahima
- Division of Endocrinology, Diabetes, & Metabolism, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
| | - Steven E. Arnold
- Alzheimer's Clinical and Translational Research Unit, Department of Neurology, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
| | - Zoe Arvanitakis
- Rush Alzheimer’s Disease Center, Rush University Medical Center, Chicago, IL, USA.
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Sawant N, Kshirsagar S, Reddy PH, Reddy AP. Protective effects of SSRI, Citalopram in mutant APP and mutant Tau expressed dorsal raphe neurons in Alzheimer's disease. Biochim Biophys Acta Mol Basis Dis 2024; 1870:166942. [PMID: 37931714 DOI: 10.1016/j.bbadis.2023.166942] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/25/2023] [Revised: 10/05/2023] [Accepted: 10/30/2023] [Indexed: 11/08/2023]
Abstract
Depression is among the most common neuropsychiatric comorbidities in Alzheimer's disease (AD) and other Tauopathies. Apart from its anti-depressive and anxiolytic effects, selective serotonin reuptake inhibitor (SSRI) treatment also offers intracellular modifications that may help to improve neurogenesis, reduce amyloid burden & Tau pathologies, and neuroinflammation in AD. Despite its multifaceted impact in the brain, the exact physiological and molecular mechanism by which SSRIs such as Citalopram improve neurogenesis and synaptogenesis in dementia is poorly understood. In the current study, we investigated the protective role of SSRI, Citalopram, in serotonergic, medullary raphe neurons (RN46A-B14). RN46A-B14 cells were transfected with wild-type and mutant APP and Tau cDNAs for 24 h and then treated with 20 μM Cit for 24 h. We then assessed mRNA and protein levels of pTau, total Tau, serotonin related proteins such as TPH2, SERT, and 5HTR1a, synaptic proteins and the cytoskeletal structure. We also assessed cell survival, mitochondrial respiration and mitochondrial morphology. The mutant APP and Tau transfected cells showed increased levels of serotonin related proteins and mRNA, while the mRNA and protein levels of synaptic proteins were downregulated. Citalopram treatment significantly reduced pathologically pTau level along with the serotonin related protein levels. On the other hand, there was a significant increase in the mRNA and protein levels of synaptic genes and cytoskeletal structure in the treated groups. Further, Citalopram also improved cell survival, mitochondrial respiration and mitochondrial morphology in the treated cells that express mAPP and mTau. Taken together these findings suggest Citalopram could not only be a promising therapeutic drug for treating patients with depression, but also for AD patients.
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Affiliation(s)
- Neha Sawant
- Nutritional Sciences Department, Texas Tech University, Lubbock, TX, USA; Internal Medicine Department, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Sudhir Kshirsagar
- Internal Medicine Department, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - P Hemachandra Reddy
- Nutritional Sciences Department, Texas Tech University, Lubbock, TX, USA; Internal Medicine Department, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Pharmacology & Neuroscience Department, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Neurology Department, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Speech, Language and Hearing Sciences Departments, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA; Public Health Department, School of Population and Public Health, Texas Tech University Health Sciences Center, Lubbock, TX 79430, USA
| | - Arubala P Reddy
- Nutritional Sciences Department, Texas Tech University, Lubbock, TX, USA.
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Vujovic F, Shepherd CE, Witting PK, Hunter N, Farahani RM. Redox-Mediated Rewiring of Signalling Pathways: The Role of a Cellular Clock in Brain Health and Disease. Antioxidants (Basel) 2023; 12:1873. [PMID: 37891951 PMCID: PMC10604469 DOI: 10.3390/antiox12101873] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/11/2023] [Revised: 10/14/2023] [Accepted: 10/15/2023] [Indexed: 10/29/2023] Open
Abstract
Metazoan signalling pathways can be rewired to dampen or amplify the rate of events, such as those that occur in development and aging. Given that a linear network topology restricts the capacity to rewire signalling pathways, such scalability of the pace of biological events suggests the existence of programmable non-linear elements in the underlying signalling pathways. Here, we review the network topology of key signalling pathways with a focus on redox-sensitive proteins, including PTEN and Ras GTPase, that reshape the connectivity profile of signalling pathways in response to an altered redox state. While this network-level impact of redox is achieved by the modulation of individual redox-sensitive proteins, it is the population by these proteins of critical nodes in a network topology of signal transduction pathways that amplifies the impact of redox-mediated reprogramming. We propose that redox-mediated rewiring is essential to regulate the rate of transmission of biological signals, giving rise to a programmable cellular clock that orchestrates the pace of biological phenomena such as development and aging. We further review the evidence that an aberrant redox-mediated modulation of output of the cellular clock contributes to the emergence of pathological conditions affecting the human brain.
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Affiliation(s)
- Filip Vujovic
- IDR/Westmead Institute for Medical Research, Sydney, NSW 2145, Australia; (F.V.); (N.H.)
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
| | | | - Paul K. Witting
- Redox Biology Group, Charles Perkins Centre, Faculty of Medicine and Health, School of Medical Sciences, The University of Sydney, Sydney, NSW 2006, Australia;
| | - Neil Hunter
- IDR/Westmead Institute for Medical Research, Sydney, NSW 2145, Australia; (F.V.); (N.H.)
| | - Ramin M. Farahani
- IDR/Westmead Institute for Medical Research, Sydney, NSW 2145, Australia; (F.V.); (N.H.)
- School of Medical Sciences, Faculty of Medicine and Health, The University of Sydney, Sydney, NSW 2006, Australia
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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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Lin NH, Goh A, Lin SH, Chuang KA, Chang CH, Li MH, Lu CH, Chen WY, Wei PH, Pan IH, Perng MD, Wen SF. Neuroprotective Effects of a Multi-Herbal Extract on Axonal and Synaptic Disruption in Vitro and Cognitive Impairment in Vivo. J Alzheimers Dis Rep 2023; 7:51-76. [PMID: 36777330 PMCID: PMC9912829 DOI: 10.3233/adr-220056] [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: 08/04/2022] [Accepted: 01/02/2023] [Indexed: 01/19/2023] Open
Abstract
Background Alzheimer's disease (AD) is a multifactorial disorder characterized by cognitive decline. Current available therapeutics for AD have limited clinical benefit. Therefore, preventive therapies for interrupting the development of AD are critically needed. Molecules targeting multifunction to interact with various pathlogical components have been considered to improve the therapeutic efficiency of AD. In particular, herbal medicines with multiplicity of actions produce cognitive benefits on AD. Bugu-M is a multi-herbal extract composed of Ganoderma lucidum (Antler form), Nelumbo nucifera Gaertn., Ziziphus jujuba Mill., and Dimocarpus longan, with the ability of its various components to confer resilience to cognitive deficits. Objective To evaluate the potential of Bugu-M on amyloid-β (Aβ) toxicity and its in vitro mechanisms and on in vivo cognitive function. Methods We illustrated the effect of Bugu-M on Aβ25-35-evoked toxicity as well as its possible mechanisms to diminish the pathogenesis of AD in rat cortical neurons. For cognitive function studies, 2-month-old female 3×Tg-AD mice were administered 400 mg/kg Bugu-M for 30 days. Behavioral tests were performed to assess the efficacy of Bugu-M on cognitive impairment. Results In primary cortical neuronal cultures, Bugu-M mitigated Aβ-evoked toxicity by reducing cytoskeletal aberrations and axonal disruption, restoring presynaptic and postsynaptic protein expression, suppressing mitochondrial damage and apoptotic signaling, and reserving neurogenic and neurotrophic factors. Importantly, 30-day administration of Bugu-M effectively prevented development of cognitive impairment in 3-month-old female 3×Tg-AD mice. Conclusion Bugu-M might be beneficial in delaying the progression of AD, and thus warrants consideration for its preventive potential for AD.
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Affiliation(s)
- Ni-Hsuan Lin
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan
| | - Angela Goh
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Shyh-Horng Lin
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Kai-An Chuang
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Chih-Hsuan Chang
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Ming-Han Li
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Chu-Hsun Lu
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Wen-Yin Chen
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Pei-Hsuan Wei
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - I-Hong Pan
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan
| | - Ming-Der Perng
- Institute of Molecular Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan,
School of Medicine, College of Life Sciences, National Tsing Hua University, Hsinchu, Taiwan,Correspondence to: Shu-Fang Wen, Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, 321, Section 2, Kuang-Fu Road, Hsinchu 300044, Taiwan. Tel.: +886 35743946; E-mail: and Ming-Der Perng, College of Life Sciences, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 300044, Taiwan. Tel.: +886 35742024; E-mail:
| | - Shu-Fang Wen
- Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, Hsinchu, Taiwan,Correspondence to: Shu-Fang Wen, Biomedical Technology and Device Research Laboratories, Industrial Technology Research Institute, 321, Section 2, Kuang-Fu Road, Hsinchu 300044, Taiwan. Tel.: +886 35743946; E-mail: and Ming-Der Perng, College of Life Sciences, National Tsing Hua University, 101, Section 2, Kuang-Fu Road, Hsinchu 300044, Taiwan. Tel.: +886 35742024; E-mail:
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Bagheri-Mohammadi S, Askari S, Alani B, Moosavi M, Ghasemi R. Cinnamaldehyde Regulates Insulin and Caspase-3 Signaling Pathways in the Sporadic Alzheimer's Disease Model: Involvement of Hippocampal Function via IRS-1, Akt, and GSK-3β Phosphorylation. J Mol Neurosci 2022; 72:2273-2291. [PMID: 36210429 DOI: 10.1007/s12031-022-02075-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2022] [Accepted: 10/01/2022] [Indexed: 12/14/2022]
Abstract
Insulin signaling disruption and caspase-3 cleavage play a pathologic role in Alzheimer's disease (AD). Evidence suggested that cinnamaldehyde (Cin), the major component of cinnamon, has the ability to act as a neuroprotective agent. However, little evidence is available to demonstrate its effectiveness in regulating the insulin and caspase-3 signaling pathways and underlying molecular mechanisms. Therefore, the present study was conducted to correlate the molecular mechanisms of these signaling pathways and Cin treatment on animal behavioral performance in an intracerebroventricular (ICV)-streptozotocin (STZ, 3 mg/kg) model. The sporadic AD rat model was treated with Cin (10 and 100 mg/kg; intraperitoneal, i.p) daily for 2 weeks. Novel object recognition (NOR), Morris water maze (MWM), and elevated plus maze (EPM) tests were performed to assess recognition/spatial memory and anxiety-like behavior, respectively. Hippocampal Aβ aggregation was assessed using Congo red staining. The activity of hippocampal caspase-3 and IRS-1/Akt/GSK-3β signaling pathways were analyzed using the Western blot technique. The results revealed that Cin (100 mg/kg, effective dose) improved recognition/spatial memory deficits and anxiety-like behavior. In addition, Cin negated the effects of STZ on Aβ aggregation and caspase-3 cleavage in the hippocampus. Furthermore, the Western blot method showed that hippocampal IRS-1/AKT/GSK-3β phosphorylation was altered in ICV-STZ animal model, while Cin modulated this signaling pathway through decreasing Phospho.IRS-1Ser307/Total.IRS-1 ratio and also increasing Phospho.AktSer473/Total.Akt and Phospho.GSK-3βSer9/Total.GSK-3β ratios. These findings suggest that Cin is involved in the regulation of hippocampal IRS-1/AKT/GSK-3β and caspase-3 pathways in a sporadic AD model, and modulation of these signaling pathways also influences the animal behavioral performance.
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Affiliation(s)
- Saeid Bagheri-Mohammadi
- Department of Physiology and Neurophysiology Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Sahar Askari
- Department of Physiology and Neurophysiology Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.,Neuroscience Research Center, Shahid Beheshti University of Medical Sciences, Tehran, Iran
| | - Behrang Alani
- Department of Applied Cell Sciences, Faculty of Medicine, Kashan University of Medical Sciences, Kashan, Iran
| | - Maryam Moosavi
- Nanomedicine and Nanobiology Research Center, Shiraz University of Medical Sciences, Shiraz, Iran.
| | - Rasoul Ghasemi
- Department of Physiology and Neurophysiology Research Center, School of Medicine, Shahid Beheshti University of Medical Sciences, Tehran, Iran.
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Yang YH, Hsieh SW, Chang HW, Sung JL, Chuu CP, Yen CW, Hour TC. Gamma Frequency Inhibits the Secretion and Aggregation of Amyloid-β and Decreases the Phosphorylation of mTOR and Tau Proteins in vitro. J Alzheimers Dis 2022; 90:917-928. [DOI: 10.3233/jad-220307] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Background: Alzheimer’s disease (AD) was the main cause of dementia in an aging society; unfortunately, there is no effective treatment for AD now. Meditation has been reported to thicken the cerebral cortex, and gamma wave at a frequency of 40 hertz (Hz) was recorded during the meditation process from the brain. Previous study showed that non-invasive scintillation gamma frequency oscillation increased the space in recognition and memory of auditory cortex hippocampal gyrus in AD mice model. However, the AD-related molecular change by exposure of 40 Hz gamma frequency in brain cells was still unclear. Objective: We investigated the AD-related molecular change by exposure of 40 Hz gamma frequency in SH-SY5Y cells. Methods: We designed the light and sound generators at 40 Hz gamma frequency for this study. SH-SY5Y cells were exposed to sound or light of 40 Hz gamma frequency, respectively. The concentrations of amyloid-β40 (Aβ40) and amyloid-β42 (Aβ42) were quantified by enzyme-linked immunosorbent assay. The protein levels were examined by western blotting. The aggregation of Aβ42 was examined by thioflavin T assay. Results: Our results showed that the secretion of Aβ, phosphorylation of AKT, mTOR, and tau, and aggregation of Aβ42 were significantly inhibited by 40 Hz gamma frequency in SH-SY5Y cells. The phosphorylation of 4E-BP1, downstream of mTOR, was induced by 40 Hz gamma frequency in SH-SY5Y cells. Conclusion: Our study showed 40 Hz gamma frequency involved in the inhibition of secretion and aggregation of Aβ and inhibition of p-Tau protein expression through the mTOR/4E-BP1/Tau signaling pathway.
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Affiliation(s)
- Yuan-Han Yang
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Master’s Program in Neurology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Neurology, Kaohsiung Municipal Ta-Tung Hospital, Kaohsiung, Taiwan
| | - Sun-Wung Hsieh
- Department of Neurology, Kaohsiung Medical University Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Neurology, Kaohsiung Municipal Hsiao-Kang Hospital, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Neurology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Hsi-Wen Chang
- Department of Biochemistry, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Jia-Li Sung
- Department of Mechanical and Electromechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
| | - Chih-Pin Chuu
- Institute of Cellular and System Medicine, National Health Research Institutes, Miaoli, Taiwan
| | - Chen-Wen Yen
- Master’s Program in Neurology, Faculty of Medicine, College of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Mechanical and Electromechanical Engineering, National Sun Yat-Sen University, Kaohsiung, Taiwan
- Department of Physical Therapy, College of Health Science, Kaohsiung Medical University, Kaohsiung, Taiwan
| | - Tzyh-Chyuan Hour
- Neuroscience Research Center, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Biochemistry, School of Medicine, Kaohsiung Medical University, Kaohsiung, Taiwan
- Department of Medical Research, Kaohsiung Medical University Hospital, Kaohsiung, Taiwan
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10
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Tafiadis D, Ziavra N, Prentza A, Siafaka V, Zarokanellou V, Voniati L, Konitsiotis S. Validation of the Greek version of the Abbreviated Mental Test Score: Preliminary findings for cognitively impaired patients of different etiology. APPLIED NEUROPSYCHOLOGY. ADULT 2022; 29:1003-1014. [PMID: 33119404 DOI: 10.1080/23279095.2020.1835915] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
BACKGROUND Screening people's cognitive skills have been proven essential for reference to full assessment. These methods include short scales, such as the Abbreviated Mental Test Score (AMTS). The AMTS is a valid 10-item questionnaire that has been translated into many languages, but not in Greek yet. The aim of this study is the validation of the Greek version of the AMTS with an additional estimation of its cutoff scores. METHODS About 132 individuals [60 controls and 72 patients (24 with Parkinson's disease (PD), 24 with Parkinson's disease dementia (PDD), and 24 with Alzheimer's disease (AD)] participated in this study. All participants besides the AMTS completed the Mini Mental State Examination (MMSE), the Tuokko's Clock Drawing Test (CDT), the Instrumental Activities of Daily Living (IADL), the Arizona Battery for Communication Disorders of Dementia (ABCD), the Hellenic versions of the Neuropsychiatric Inventory (NPI), and the Geriatric Depression Scale (GDS-15). RESULTS Statistically significant differences were found between all subgroups for the AMTS. The AMTS showed high internal consistency (Cronbach alpha = 0.819 and coefficient omega ω = 0.814). A threshold equal to 6.50 (AUC: 0.908, p = 0.000) between groups with and without cognitive impairment was calculated. The AMTS was significantly correlated with the CDT, IADL, and MMSE. CONCLUSION The proposed version of the AMTS can distinguish between groups with and without cognitive impairment. Additionally, the AMTS is found to be clinically valid having high reliability and classification accuracy. Conclusively, it is a valuable instrument for screening different types of cognitively impaired patients.
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Affiliation(s)
- Dionysios Tafiadis
- Department of Speech and Language Therapy, School of Health Sciences, University of Ioannina, Ioannina, Greece
- Department of Health Sciences, Speech and Language Therapy, European University, Nicosia, Cyprus
| | - Nafsika Ziavra
- Department of Speech and Language Therapy, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Alexandra Prentza
- Department of Linguistics, School of Philology, Faculty of Philosophy, University of Ioannina, Greece
| | - Vassiliki Siafaka
- Department of Speech and Language Therapy, School of Health Sciences, University of Ioannina, Ioannina, Greece
| | - Vasiliki Zarokanellou
- Department of Speech and Language Therapy, School of Rehabilitation Sciences, University of Patras, Patras, Greece
| | - Louiza Voniati
- Department of Health Sciences, Speech and Language Therapy, European University, Nicosia, Cyprus
| | - Spyridon Konitsiotis
- Department of Medicine, School of Health Sciences, University of Ioannina, Ioannina, Greece
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11
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Yang JJ. Brain insulin resistance and the therapeutic value of insulin and insulin-sensitizing drugs in Alzheimer's disease neuropathology. Acta Neurol Belg 2022; 122:1135-1142. [PMID: 35482277 DOI: 10.1007/s13760-022-01907-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2022] [Accepted: 02/17/2022] [Indexed: 02/06/2023]
Abstract
The incidence of Alzheimer's disease (AD) is significantly higher in people with diabetes. Insulin and insulin receptor (IR) signaling intermediates are expressed in the brain. Insulin exerts multiple function in the brain. The role of compromised IR signaling in AD pathogenesis and the therapeutic value of insulin attract broad attention. This review summarizes the collective insulin action in the brain related to key factors of AD pathogenesis, updates the key features of insulin resistance in the AD brain and assesses the therapeutic potential of insulin and insulin-sensitizing drugs. Insulin stimulates neural growth and survival, suppresses amyloidogenic processing of the amyloid precursor protein (AβPP) and inhibits the Tau phosphorylation kinase, glycogen synthase kinase 3β. Central nervous IR signaling regulates systemic metabolism and increases glucose availability to neurons. The expression of IR and its downstream effectors is reduced in AD brain tissues. Insulin and insulin-sensitizing drugs can improve cognitive function in AD patients and AD animal models. Systemic insulin delivery is less effective than intranasal insulin treatment. The penetrance of insulin-sensitizing drugs to the blood brain barrier is problematic and new brain-prone drugs need be developed. Insulin resistance manifested by the degradation and the altered phosphorylation of IR intermediates precedes overt AD syndrome. Type 3 diabetes as a pure form of brain insulin resistance without systemic insulin resistance is proposed as a causal factor in AD. Further research is needed for the identification of critical factors leading to impaired IR signaling and the development of new molecules to stimulate brain IR signaling.
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Affiliation(s)
- James J Yang
- Marriotts Ridge High School, 12100 Woodford Dr, Marriottsville, MD, 21104, USA.
- , 3060 Seneca Chief Trail, Ellicott City, MD, 21042, USA.
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12
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Alves SS, da Silva Junior RMP, Delfino-Pereira P, Pereira MGAG, Vasconcelos I, Schwaemmle H, Mazzei RF, Carlos ML, Espreafico EM, Tedesco AC, Sebollela A, Almeida SS, de Oliveira JAC, Garcia-Cairasco N. A Genetic Model of Epilepsy with a Partial Alzheimer's Disease-Like Phenotype and Central Insulin Resistance. Mol Neurobiol 2022; 59:3721-3737. [PMID: 35378696 DOI: 10.1007/s12035-022-02810-w] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/04/2021] [Accepted: 03/22/2022] [Indexed: 12/20/2022]
Abstract
Studies have suggested an important connection between epilepsy and Alzheimer's disease (AD), mostly due to the high number of patients diagnosed with AD who develop epileptic seizures later on. However, this link is not well understood. Previous studies from our group have identified memory impairment and metabolic abnormalities in the Wistar audiogenic rat (WAR) strain, a genetic model of epilepsy. Our goal was to investigate AD behavioral and molecular alterations, including brain insulin resistance, in naïve (seizure-free) animals of the WAR strain. We used the Morris water maze (MWM) test to evaluate spatial learning and memory performance and hippocampal tissue to verify possible molecular and immunohistochemical alterations. WARs presented worse performance in the MWM test (p < 0.0001), higher levels of hyperphosphorylated tau (S396) (p < 0.0001) and phosphorylated glycogen synthase kinase 3 (S21/9) (p < 0.05), and lower insulin receptor levels (p < 0.05). Conversely, WARs and Wistar controls present progressive increase in amyloid fibrils (p < 0.0001) and low levels of soluble amyloid-β. Interestingly, the detected alterations were age-dependent, reaching larger differences in aged than in young adult animals. In summary, the present study provides evidence of a partial AD-like phenotype, including altered regulation of insulin signaling, in a genetic model of epilepsy. Together, these data contribute to the understanding of the connection between epilepsy and AD as comorbidities. Moreover, since both tau hyperphosphorylation and altered insulin signaling have already been reported in epilepsy and AD, these two events should be considered as important components in the interconnection between epilepsy and AD pathogenesis and, therefore, potential therapeutic targets in this field.
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Affiliation(s)
- Suélen Santos Alves
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Ribeirao Preto, Brazil
| | | | - Polianna Delfino-Pereira
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Ribeirao Preto, Brazil
| | | | - Israel Vasconcelos
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Ribeirao Preto, Brazil
| | - Hanna Schwaemmle
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Ribeirao Preto, Brazil
| | - Rodrigo Focosi Mazzei
- Department of Psychology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo (FFCLRP-USP), Ribeirao Preto, Brazil
| | - Maiko Luiz Carlos
- Department of Chemistry, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo (FFCLRP-USP), Ribeirao Preto, Brazil
| | - Enilza Maria Espreafico
- Department of Cell and Molecular Biology and Pathogenic Bioagents, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Ribeirao Preto, Brazil
| | - Antônio Claudio Tedesco
- Department of Chemistry, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo (FFCLRP-USP), Ribeirao Preto, Brazil
| | - Adriano Sebollela
- Department of Biochemistry and Immunology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Ribeirao Preto, Brazil
| | - Sebastião Sousa Almeida
- Department of Psychology, Faculty of Philosophy, Sciences and Letters of Ribeirão Preto, University of São Paulo (FFCLRP-USP), Ribeirao Preto, Brazil
| | - José Antônio Cortes de Oliveira
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Av. Dos Bandeirantes 3900, Ribeirao Preto, SP, 14049-900, Brazil
| | - Norberto Garcia-Cairasco
- Department of Neurosciences and Behavioral Sciences, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Ribeirao Preto, Brazil.
- Department of Physiology, Ribeirão Preto Medical School - University of São Paulo (FMRP-USP), Av. Dos Bandeirantes 3900, Ribeirao Preto, SP, 14049-900, Brazil.
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13
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Querfurth H, Marshall J, Parang K, Rioult-Pedotti MS, Tiwari R, Kwon B, Reisinger S, Lee HK. A PDK-1 allosteric agonist neutralizes insulin signaling derangements and beta-amyloid toxicity in neuronal cells and in vitro. PLoS One 2022; 17:e0261696. [PMID: 35061720 PMCID: PMC8782417 DOI: 10.1371/journal.pone.0261696] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2021] [Accepted: 12/08/2021] [Indexed: 01/09/2023] Open
Abstract
The Alzheimer's brain is affected by multiple pathophysiological processes, which include a unique, organ-specific form of insulin resistance that begins early in its course. An additional complexity arises from the four-fold risk of Alzheimer's Disease (AD) in type 2 diabetics, however there is no definitive proof of causation. Several strategies to improve brain insulin signaling have been proposed and some have been clinically tested. We report findings on a small allosteric molecule that reverses several indices of insulin insensitivity in both cell culture and in vitro models of AD that emphasize the intracellular accumulation of β-amyloid (Aβi). PS48, a chlorophenyl pentenoic acid, is an allosteric activator of PDK-1, which is an Akt-kinase in the insulin/PI3K pathway. PS48 was active at 10 nM to 1 μM in restoring normal insulin-dependent Akt activation and in mitigating Aβi peptide toxicity. Synaptic plasticity (LTP) in prefrontal cortical slices from normal rat exposed to Aβ oligomers also benefited from PS48. During these experiments, neither overstimulation of PI3K/Akt signaling nor toxic effects on cells was observed. Another neurotoxicity model producing insulin insensitivity, utilizing palmitic acid, also responded to PS48 treatment, thus validating the target and indicating that its therapeutic potential may extend outside of β-amyloid reliance. The described in vitro and cell based-in vitro coupled enzymatic assay systems proved suitable platforms to screen a preliminary library of new analogs.
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Affiliation(s)
- Henry Querfurth
- Department of Neurology, Tufts Medical Center, Boston, MA, United States of America
| | - John Marshall
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States of America
| | - Keykavous Parang
- Center for Targeted Drug Delivery, Chapman University, School of Pharmacology, Irvine, CA United States of America
| | - Mengia S. Rioult-Pedotti
- Department of Molecular Pharmacology, Physiology, and Biotechnology, Brown University, Providence, RI, United States of America
- Department of Neurology, Clinical Neurorehabilitation, University of Zurich, Zurich, Switzerland
| | - Rakesh Tiwari
- Center for Targeted Drug Delivery, Chapman University, School of Pharmacology, Irvine, CA United States of America
| | - Bumsup Kwon
- Department of Neurology, Rhode Island Hospital, Providence, RI, United States of America
| | | | - Han-Kyu Lee
- Department of Neurology, Tufts Medical Center, Boston, MA, United States of America
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14
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Kwon OH, Cho YY, Lee JH, Chung S. O-GlcNAcylation Inhibits Endocytosis of Amyloid Precursor Protein by Decreasing Its Localization in Lipid Raft Microdomains. MEMBRANES 2021; 11:membranes11120909. [PMID: 34940409 PMCID: PMC8704492 DOI: 10.3390/membranes11120909] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/19/2021] [Revised: 11/16/2021] [Accepted: 11/19/2021] [Indexed: 12/27/2022]
Abstract
Like protein phosphorylation, O-GlcNAcylation is a common post-translational protein modification. We already reported that O-GlcNAcylation of amyloid precursor protein (APP) in response to insulin signaling reduces neurotoxic amyloid-β (Aβ) production via inhibition of APP endocytosis. Internalized APP is delivered to endosomes and lysosomes where Aβ is produced. However, the molecular mechanism involved in the effect of APP O-GlcNAcylation on APP trafficking remains unknown. To investigate the relationship between APP O-GlcNAcylation and APP endocytosis, we tested the effects of insulin on neuroblastoma SH-SY5Y cells overexpressing APP and BACE1, and cultured rat hippocampal neurons. The present study showed that APP O-GlcNAcylation translocated APP from lipid raft to non-raft microdomains in the plasma membrane by using immunocytochemistry and discontinuous sucrose gradients method. By using the biotinylation method, we also found that APP preferentially underwent endocytosis from lipid rafts and that the amount of internalized APP from lipid rafts was specifically reduced by O-GlcNAcylation. These results indicate that O-GlcNAcylation can regulate lipid raft-dependent APP endocytosis via translocation of APP into non-raft microdomains. Our findings showed a new functional role of O-GlcNAcylation for the regulation of APP trafficking, offering new mechanistic insight for Aβ production.
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Affiliation(s)
- Oh-Hoon Kwon
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon 16419, Korea; (O.-H.K.); (Y.Y.C.)
| | - Yoon Young Cho
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon 16419, Korea; (O.-H.K.); (Y.Y.C.)
| | - Jung Hee Lee
- Department of Radiology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul 06351, Korea;
| | - Sungkwon Chung
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon 16419, Korea; (O.-H.K.); (Y.Y.C.)
- Correspondence:
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15
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Andrés-Benito P, Carmona M, Pirla MJ, Torrejón-Escribano B, Del Rio JA, Ferrer I. Dysregulated Protein Phosphorylation as Main Contributor of Granulovacuolar Degeneration at the First Stages of Neurofibrillary Tangles Pathology. Neuroscience 2021; 518:119-140. [PMID: 34757172 DOI: 10.1016/j.neuroscience.2021.10.023] [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: 06/21/2021] [Revised: 10/19/2021] [Accepted: 10/21/2021] [Indexed: 02/08/2023]
Abstract
The hippocampus of cases with neurofibrillary tangles (NFT) pathology classified as stages I-II, III-IV, and V-VI without comorbidities, and middle-aged (MA) individuals with no NFT pathology, were examined to learn about the composition of granulovacuolar degeneration (GVD). Our results confirm the presence of CK1-δ, p38-P Thr180/Tyr182, SAPK/JNK-P Thr183/Thr185, GSK-3α/β-P Tyr279/Tyr216, and GSK-3β Ser9 in the cytoplasmic granules in a subset of neurons of the CA1 and CA2 subfields of the hippocampus. Also, we identify the presence of PKA α/β-P Thr197, SRC-P Tyr416, PAK1-P Ser199/Ser204, CAMK2A-P Tyr197, and PKCG-P Thr655 in cytoplasmic granules in cases with NFT pathology, but not in MA cases. Our results also confirm the presence of β-catenin-P Ser45/Thr41, IREα-P Ser274, eIF2α-P Ser51, TDP-43-P Ser403-404 (but absent TDP-43), and ubiquitin in cytoplasmic granules. Other components of the cytoplasmic granules are MAP2-P Thr1620/1623, MAP1B-P Thr1265, ADD1-P Ser726, and ADD1/ADD1-P Ser726/Ser713, in addition to several tau species including 3Rtau, 4Rtau, and tau-P Ser262. The analysis of GVD at progressive stages of NFT pathology reveals the early appearance of phosphorylated kinases and proteins in cytoplasmic granules at stages I-II, before the appearance of pre-tangles and NFTs. Most of these granules are not surrounded by LAMP1-positive membranes. Markers of impaired ubiquitin-protesome system, abnormal reticulum stress response, and altered endocytic and autophagic pathways occur in a subpopulation of neurons containing cytoplasmic granules, and they appear later. These observations suggest early phosphorylation of kinases leading to their activation, and resulting in the abnormal phosphorylation of various substrates, including tau, as a main alteration at the first stages of GVD.
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Affiliation(s)
- Pol Andrés-Benito
- Department of Pathology and Experimental Therapeutics, University of Barcelona, CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, Bellvitge University Hospital/Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain.
| | - Margarita Carmona
- Department of Pathology and Experimental Therapeutics, University of Barcelona, CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, Bellvitge University Hospital/Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain.
| | - Mónica Jordán Pirla
- Department of Pathology and Experimental Therapeutics, University of Barcelona, CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, Bellvitge University Hospital/Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain.
| | - Benjamín Torrejón-Escribano
- Advanced Light Microscopy Unit (Campus de Bellvitge), Scientific and Technical Facility (CCiTUB), University of Barcelona, Hospitalet de Llobregat, Spain.
| | - José Antonio Del Rio
- Molecular and Cellular Neurobiotechnology, Institute of Bioengineering of Catalonia (IBEC), Barcelona Institute for Science and Technology, Science Park Barcelona (PCB), Barcelona, Spain; Department of Cell Biology, Physiology and Immunology, Faculty of Biology, University of Barcelona, Spain.
| | - Isidro Ferrer
- Department of Pathology and Experimental Therapeutics, University of Barcelona, CIBERNED (Network Centre of Biomedical Research of Neurodegenerative Diseases), Institute of Health Carlos III, Bellvitge University Hospital/Bellvitge Biomedical Research Institute (IDIBELL), Hospitalet de Llobregat, Barcelona, Spain.
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16
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Cheng KC, Chen YH, Wu CL, Lee WP, Cheung CHA, Chiang HC. Rac1 and Akt Exhibit Distinct Roles in Mediating Aβ-Induced Memory Damage and Learning Impairment. Mol Neurobiol 2021; 58:5224-5238. [PMID: 34273104 DOI: 10.1007/s12035-021-02471-1] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/07/2021] [Accepted: 06/24/2021] [Indexed: 11/25/2022]
Abstract
Accumulated beta-amyloid (Aβ) in the brain is the hallmark of Alzheimer's disease (AD). Despite Aβ accumulation is known to trigger cellular dysfunctions and learning and memory damage, the detailed molecular mechanism remains elusive. Recent studies have shown that the onset of memory impairment and learning damage in the AD animal is different, suggesting that the underlying mechanism of the development of memory impairment and learning damage may not be the same. In the current study, with the use of Aβ42 transgenic flies as models, we found that Aβ induces memory damage and learning impairment via differential molecular signaling pathways. In early stage, Aβ activates both Ras and PI3K to regulate Rac1 activity, which affects mostly on memory performance. In later stage, PI3K-Akt is strongly activated by Aβ, which leads to learning damage. Moreover, reduced Akt, but not Rac1, activity promotes cell viability in the Aβ42 transgenic flies, indicating that Akt and Rac1 exhibit differential roles in Aβ regulating toxicity. Taken together, different molecular and cellular mechanisms are involved in Aβ-induced learning damage and memory decline; thus, caution should be taken during the development of therapeutic intervention in the future.
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Affiliation(s)
- Kuan-Chung Cheng
- Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng-Kung University, Tainan, Taiwan
| | - Ying-Hao Chen
- Division of Neurology, Department of Internal Medicine, Ditmanson Medical Foundation Chia-Yi Christian Hospital, Chiayi, Taiwan
- Department of Neurology, Taipei Veterans General Hospital, Taipei, Taiwan
| | - Chia-Lin Wu
- Department of Biochemistry and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
- Department of Neurology, Chang Gung Memorial Hospital, Linkou, Taiwan
| | - Wang-Pao Lee
- Department of Biochemistry and Graduate Institute of Biomedical Sciences, College of Medicine, Chang Gung University, Taoyuan, Taiwan
| | - Chun Hei Antonio Cheung
- Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan
- Institute of Basic Medical Sciences, College of Medicine, National Cheng-Kung University, Tainan, Taiwan
| | - Hsueh-Cheng Chiang
- Department of Pharmacology, College of Medicine, National Cheng-Kung University, Tainan, Taiwan.
- Institute of Basic Medical Sciences, College of Medicine, National Cheng-Kung University, Tainan, Taiwan.
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17
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Querfurth H, Lee HK. Mammalian/mechanistic target of rapamycin (mTOR) complexes in neurodegeneration. Mol Neurodegener 2021; 16:44. [PMID: 34215308 PMCID: PMC8252260 DOI: 10.1186/s13024-021-00428-5] [Citation(s) in RCA: 106] [Impact Index Per Article: 35.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/29/2020] [Accepted: 02/01/2021] [Indexed: 12/12/2022] Open
Abstract
Novel targets to arrest neurodegeneration in several dementing conditions involving misfolded protein accumulations may be found in the diverse signaling pathways of the Mammalian/mechanistic target of rapamycin (mTOR). As a nutrient sensor, mTOR has important homeostatic functions to regulate energy metabolism and support neuronal growth and plasticity. However, in Alzheimer's disease (AD), mTOR alternately plays important pathogenic roles by inhibiting both insulin signaling and autophagic removal of β-amyloid (Aβ) and phospho-tau (ptau) aggregates. It also plays a role in the cerebrovascular dysfunction of AD. mTOR is a serine/threonine kinase residing at the core in either of two multiprotein complexes termed mTORC1 and mTORC2. Recent data suggest that their balanced actions also have implications for Parkinson's disease (PD) and Huntington's disease (HD), Frontotemporal dementia (FTD) and Amyotrophic Lateral Sclerosis (ALS). Beyond rapamycin; an mTOR inhibitor, there are rapalogs having greater tolerability and micro delivery modes, that hold promise in arresting these age dependent conditions.
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Affiliation(s)
- Henry Querfurth
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA.
| | - Han-Kyu Lee
- Department of Neurology, Tufts Medical Center, Boston, Massachusetts, USA
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18
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Kelliny S, Lin L, Deng I, Xiong J, Zhou F, Al-Hawwas M, Bobrovskaya L, Zhou XF. A New Approach to Model Sporadic Alzheimer's Disease by Intracerebroventricular Streptozotocin Injection in APP/PS1 Mice. Mol Neurobiol 2021; 58:3692-3711. [PMID: 33797693 DOI: 10.1007/s12035-021-02338-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/15/2020] [Accepted: 02/22/2021] [Indexed: 12/30/2022]
Abstract
Alzheimer's disease (AD) is the most common cause of dementia among elderly people. Majority of AD cases are sporadic (SAD) with unknown cause. Transgenic animal models closely reflect the familial (genetic) aspect of the disease but not the sporadic type. However, most new drug candidates which are tested positive in transgenic animal models failed in clinical studies so far. Herein, we aim to develop an AD animal model that combines most of the neuropathological features seen in sporadic AD in humans with amyloid plaques observed in transgenic mice. Four-month-old wild-type and APP/PS1 AD mice were given a single intracerebroventricular (ICV) injection of 3 mg/kg streptozotocin (STZ), a diabetogenic agent. Three weeks later, their cognitive behavior was assessed, and their brain tissues were collected for biochemical and histological analysis. STZ produced cognitive deficits in both non-transgenic mice and AD mice. Biochemical analysis showed a severe decline in synaptic proteins, increase in tau phosphorylation, oxidative stress, disturbed brain insulin signaling with extensive neuroinflammation, and cell death. Significant increase was also observed in the level of the soluble beta amyloid precursor protein (APP) fragments and robust accumulation of amyloid plaques in AD mice compared to the control. These results suggest that STZ ICV treatment causes disturbance in multiple metabolic and cell signaling pathways in the brain that facilitated amyloid plaque accumulation and tau phosphorylation. Therefore, this animal model can be used to evaluate new AD therapeutic agents for clinical translation.
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Affiliation(s)
- Sally Kelliny
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia
- Faculty of Pharmacy, Assiut University, Assiut, Egypt
| | - Liying Lin
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Isaac Deng
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Jing Xiong
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia
- Department of Neurology, The Second Affiliated Hospital, Kunming Medical University, Kunming, Yunnan Province, China
| | - Fiona Zhou
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Mohammed Al-Hawwas
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia
| | - Larisa Bobrovskaya
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia.
| | - Xin-Fu Zhou
- Health and Biomedical Innovation, Clinical and Health Sciences, University of South Australia, Adelaide, SA, 5000, Australia.
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19
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Ferreira ST. Brain insulin, insulin-like growth factor 1 and glucagon-like peptide 1 signalling in Alzheimer's disease. J Neuroendocrinol 2021; 33:e12959. [PMID: 33739563 DOI: 10.1111/jne.12959] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/01/2020] [Revised: 02/07/2021] [Accepted: 02/12/2021] [Indexed: 12/13/2022]
Abstract
Although the brain was once considered an insulin-independent organ, insulin signalling is now recognised as being central to neuronal health and to the function of synapses and brain circuits. Defective brain insulin signalling, as well as related signalling by insulin-like growth factor 1 (IGF-1), is associated with neurological disorders, including Alzheimer's disease, suggesting that cognitive impairment could be related to a state of brain insulin resistance. Here, I briefly review key epidemiological/clinical evidence of the association between diabetes, cognitive decline and AD, as well as findings of reduced components of insulin signalling in AD brains, which led to the initial suggestion that AD could be a type of brain diabetes. Particular attention is given to recent studies illuminating mechanisms leading to neuronal insulin resistance as a key driver of cognitive impairment in AD. Evidence of impaired IGF-1 signalling in AD is also examined. Finally, we discuss potentials and possible limitations of recent and on-going therapeutic approaches based on our increased understanding of the roles of brain signalling by insulin, IGF-1 and glucagon-like peptide 1 in AD.
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Affiliation(s)
- Sergio T Ferreira
- Institute of Biophysics Carlos Chagas Filho, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
- Institute of Medical Biochemistry Leopoldo de Meis, Federal University of Rio de Janeiro, Rio de Janeiro, Brazil
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van der Westhuizen ET, Choy KHC, Valant C, McKenzie-Nickson S, Bradley SJ, Tobin AB, Sexton PM, Christopoulos A. Fine Tuning Muscarinic Acetylcholine Receptor Signaling Through Allostery and Bias. Front Pharmacol 2021; 11:606656. [PMID: 33584282 PMCID: PMC7878563 DOI: 10.3389/fphar.2020.606656] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2020] [Accepted: 11/30/2020] [Indexed: 12/18/2022] Open
Abstract
The M1 and M4 muscarinic acetylcholine receptors (mAChRs) are highly pursued drug targets for neurological diseases, in particular for Alzheimer's disease and schizophrenia. Due to high sequence homology, selective targeting of any of the M1-M5 mAChRs through the endogenous ligand binding site has been notoriously difficult to achieve. With the discovery of highly subtype selective mAChR positive allosteric modulators in the new millennium, selectivity through targeting an allosteric binding site has opened new avenues for drug discovery programs. However, some hurdles remain to be overcome for these promising new drug candidates to progress into the clinic. One challenge is the potential for on-target side effects, such as for the M1 mAChR where over-activation of the receptor by orthosteric or allosteric ligands can be detrimental. Therefore, in addition to receptor subtype selectivity, a drug candidate may need to exhibit a biased signaling profile to avoid such on-target adverse effects. Indeed, recent studies in mice suggest that allosteric modulators for the M1 mAChR that bias signaling toward specific pathways may be therapeutically important. This review brings together details on the signaling pathways activated by the M1 and M4 mAChRs, evidence of biased agonism at these receptors, and highlights pathways that may be important for developing new subtype selective allosteric ligands to achieve therapeutic benefit.
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Affiliation(s)
- Emma T. van der Westhuizen
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - K. H. Christopher Choy
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Celine Valant
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Simon McKenzie-Nickson
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Sophie J. Bradley
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Andrew B. Tobin
- Centre for Translational Pharmacology, Institute of Molecular Cell and Systems Biology, University of Glasgow, Glasgow, United Kingdom
| | - Patrick M. Sexton
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
| | - Arthur Christopoulos
- Drug Discovery Biology, Monash Institute for Pharmaceutical Research, Monash University, Parkville, VIC, Australia
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Calabrò M, Rinaldi C, Santoro G, Crisafulli C. The biological pathways of Alzheimer disease: a review. AIMS Neurosci 2020; 8:86-132. [PMID: 33490374 PMCID: PMC7815481 DOI: 10.3934/neuroscience.2021005] [Citation(s) in RCA: 106] [Impact Index Per Article: 26.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/24/2020] [Accepted: 11/23/2020] [Indexed: 12/18/2022] Open
Abstract
Alzheimer disease is a progressive neurodegenerative disorder, mainly affecting older people, which severely impairs patients' quality of life. In the recent years, the number of affected individuals has seen a rapid increase. It is estimated that up to 107 million subjects will be affected by 2050 worldwide. Research in this area has revealed a lot about the biological and environmental underpinnings of Alzheimer, especially its correlation with β-Amyloid and Tau related mechanics; however, the precise molecular events and biological pathways behind the disease are yet to be discovered. In this review, we focus our attention on the biological mechanics that may lie behind Alzheimer development. In particular, we briefly describe the genetic elements and discuss about specific biological processes potentially associated with the disease.
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Affiliation(s)
| | | | | | - Concetta Crisafulli
- Department of Biomedical and Dental Sciences and Morphofunctional Imaging, University of Messina, Italy
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22
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Kwon OH, Cho YY, Kim TW, Chung S. O-GlcNAcylation of Amyloid-β Protein Precursor by Insulin Signaling Reduces Amyloid-β Production. J Alzheimers Dis 2020; 69:1195-1211. [PMID: 31156159 DOI: 10.3233/jad-190060] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Alzheimer's disease (AD) is caused by the accumulation of neurotoxic amyloid-β (Aβ) peptides. Aβ is derived from amyloid-β protein precursor (AβPP). In the non-amyloidogenic pathway, AβPP is cleaved by α-secretase and γ-secretase at the plasma membrane, excluding Aβ production. Alternatively, AβPP in the plasma membrane is internalized via endocytosis, and delivered to early endosomes and lysosomes, where it is cleaved by β-secretase and γ-secretase. Recent studies have shown that insulin in the periphery crosses the blood-brain barrier, and plays important roles in the brain. Furthermore, impaired insulin signaling has been linked to the progression of AD, and intranasal insulin administration improves memory impairments and cognition. However, the underlying molecular mechanisms of insulin treatment remain largely unknown. To investigate the effects of insulin on AβPP processing, we tested the effects of insulin on neuroblastoma SH-SY5Y cells overexpressing AβPP, and cultured rat cortical neurons. We found that insulin increased the level of cell surface AβPP, decreasing the endocytosis rate of AβPP. Insulin reduced Aβ generation through upregulation of AβPP O-GlcNAcylation via Akt insulin signaling. Our present data suggest that insulin affects Aβ production by regulating AβPP processing through AβPP O-GlcNAcylation. These results provide mechanistic insight into the beneficial effects of insulin, and a possible link between insulin deficient diabetes and cerebral amyloidosis in the pathogenesis of AD.
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Affiliation(s)
- Oh Hoon Kwon
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Yoon Young Cho
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon, South Korea
| | - Tae-Wan Kim
- Department of Pathology and Cell Biology, and Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University Medical Center, New York, NY, USA
| | - Sungkwon Chung
- Department of Physiology, Sungkyunkwan University School of Medicine, Suwon, South Korea
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Effect of memantine on expression of Bace1-as and Bace1 genes in STZ-induced Alzheimeric rats. Mol Biol Rep 2020; 47:5737-5745. [PMID: 32648077 DOI: 10.1007/s11033-020-05629-7] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2020] [Accepted: 06/26/2020] [Indexed: 01/05/2023]
Abstract
Recent studies have showed that the long non-coding RNAs (lncRNAs) expression is dysregulated in different neurodegenerative disorders like Alzheimer's disease (AD). In the present study, the effects of memantine on the level of Bace1-as and Bace1 genes' expression in streptozotocin (STZ)-induced Alzheimer's and memantine treated rats were investigated. The male Wistar rats were randomly divided into four groups: 1-Normal control, 2-Sham-operated control, 3- Alzheimer'scontrol rats (ICV-STZ), 4-Experimental group rats treated by memantine in a dose of 30 mg/kg/day for 28 days in ICV-STZ rats. The expression of Bace1-as and Bace1 genes was measured by quantitative-PCR in the brain and blood tissues. ELISA was used to analyze Bace1 and Aβ proteins. Expression of Bace1-as was significantly increased in the brain and blood tissues of the experimental group (p = 0.032 and p = 0.034, respectively). The expression of Bace1 gene showed no significant changes in the brain. Furthermore, the ELISA analysis revealed that Bace1 protein was significantly increased in the plasma of the Alzheimer's control group (p = 0.000) and in the brain tissue of the experimental group (p = 0.000). Additionally, Aβ levels had no significant changes between all groups studied. The Bace1 protein may be used as a prognostic biomarker in plasma, or before using memantine as a treatment. Furthermore, Bace1-as gene expression may play a role in monitoring the progression of AD.
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Sulfhydration of AKT triggers Tau-phosphorylation by activating glycogen synthase kinase 3β in Alzheimer's disease. Proc Natl Acad Sci U S A 2020; 117:4418-4427. [PMID: 32051249 DOI: 10.1073/pnas.1916895117] [Citation(s) in RCA: 34] [Impact Index Per Article: 8.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022] Open
Abstract
In Alzheimer's disease (AD), human Tau is phosphorylated at S199 (hTau-S199-P) by the protein kinase glycogen synthase kinase 3β (GSK3β). HTau-S199-P mislocalizes to dendritic spines, which induces synaptic dysfunction at the early stage of AD. The AKT kinase, once phosphorylated, inhibits GSK3β by phosphorylating it at S9. In AD patients, the abundance of phosphorylated AKT with active GSK3β implies that phosphorylated AKT was unable to inactivate GSK3β. However, the underlying mechanism of the inability of phosphorylated AKT to phosphorylate GSK3β remains unknown. Here, we show that total AKT and phosphorylated AKT was sulfhydrated at C77 due to the induction of intracellular hydrogen sulfide (H2S). The increase in intracellular H2S levels resulted from the induction of the proinflammatory cytokine, IL-1β, which is a pathological hallmark of AD. Sulfhydrated AKT does not interact with GSK3β, and therefore does not phosphorylate GSK3β. Thus, active GSK3β phosphorylates Tau aberrantly. In a transgenic knockin mouse (AKT-KI+/+) that lacked sulfhydrated AKT, the interaction between AKT or phospho-AKT with GSK3β was restored, and GSK3β became phosphorylated. In AKT-KI+/+ mice, expressing the pathogenic human Tau mutant (hTau-P301L), the hTau S199 phosphorylation was ameliorated as GSK3β phosphorylation was regained. This event leads to a decrease in dendritic spine loss by reducing dendritic localization of hTau-S199-P, which improves cognitive dysfunctions. Sulfhydration of AKT was detected in the postmortem brains from AD patients; thus, it represents a posttranslational modification of AKT, which primarily contributes to synaptic dysfunction in AD.
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Tramutola A, Lanzillotta C, Di Domenico F, Head E, Butterfield DA, Perluigi M, Barone E. Brain insulin resistance triggers early onset Alzheimer disease in Down syndrome. Neurobiol Dis 2020; 137:104772. [PMID: 31987911 DOI: 10.1016/j.nbd.2020.104772] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Revised: 01/03/2020] [Accepted: 01/23/2020] [Indexed: 01/08/2023] Open
Abstract
Dysregulation of insulin signaling pathway with reduced downstream neuronal survival and plasticity mechanisms is a fundamental abnormality observed in Alzheimer's disease (AD) brain. This phenomenon, known as brain insulin resistance, is associated with poor cognitive performance and is driven by the uncoupling of insulin receptor (IR) from its direct substrate (IRS1). Considering that Down syndrome (DS) and AD neuropathology share many common features, we investigated metabolic aspects of neurodegeneration, i.e., brain insulin resistance, in DS and whether it would contribute to early onset AD in DS population. Changes of levels and activation of main brain proteins belonging to the insulin signaling pathway (i.e., IR, IRS1, PTEN, GSK3β, PKCζ, AS160, GLUT4) were evaluated. Furthermore, we analyzed whether changes of these proteins were associated with alterations of: (i) proteins regulating brain energy metabolism; (ii) APP cleavage; and (ii) regulation of synaptic plasticity mechanisms in post-mortem brain samples collected from people with DS before and after the development of AD pathology (DSAD) compared with their age-matched controls. We found that DS cases were characterized by key markers of brain insulin resistance (reduced IR and increased IRS1 inhibition) early in life. Furthermore, downstream from IRS1, an overall uncoupling among the proteins of insulin signaling was observed. Dysregulated brain insulin signaling was associated with reduced hexokinase II (HKII) levels and proteins associated with mitochondrial complexes levels as well as with reduced levels of syntaxin in DS cases. Tellingly, these alterations precede the development of AD neuropathology and clinical presentations in DS. We propose that markers of brain insulin resistance rise earlier with age in DS compared with the general population and may contribute to the cognitive impairment associated with the early development of AD in DS.
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Affiliation(s)
- Antonella Tramutola
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy
| | - Chiara Lanzillotta
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy
| | - Fabio Di Domenico
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy
| | - Elizabeth Head
- Department of Pathology & Laboratory Medicine, Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, CA 92697, USA
| | - D Allan Butterfield
- Department of Chemistry, Markey Cancer Center, Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
| | - Marzia Perluigi
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy.
| | - Eugenio Barone
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, 00185 Roma, Italy.
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Cai X, Zhang K, Xie X, Zhu X, Feng J, Jin Z, Zhang H, Tian M, Chen H. Self-assembly hollow manganese Prussian white nanocapsules attenuate Tau-related neuropathology and cognitive decline. Biomaterials 2019; 231:119678. [PMID: 31864019 DOI: 10.1016/j.biomaterials.2019.119678] [Citation(s) in RCA: 33] [Impact Index Per Article: 6.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/02/2019] [Revised: 12/06/2019] [Accepted: 12/08/2019] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a prevalent chronic neurodegenerative disease. However, to date, none of the developed drug candidates targeting at a single therapeutic target of AD have achieved success in clinical trials. Herein, we proposed a hypothesis of hollow manganese Prussian white nanocapsules (HMPWCs)-mediated attenuation of Tau-related pathology and alleviation of cognitive decline via simultaneously alleviating neuroinflammation, scavenging reactive oxygen species, and reducing hyperphosphorylated Tau proteins. The HMPWCs self-assemblied with manganese Prussian white analogue and bovine serum albumin via a novel biomimetic mineralization present good biocompatibility, variable valence states, and low oxidation-reduction potential. They own the outstanding capabilities of relieving oxidative stress, inhibiting Tau neuropathology, and counteracting neuroinflammation, which could be used to treat Tau-related AD-like neurodegeneration. Importantly, they can also attenuate the cognitive impairments of Tau-related AD-like rats without significant side effects. This research takes the advantages of catalytic chemistry, nanomedicine and specific neurodegenerative microenvironment together, providing an alternative efficient treatment strategy for Tau-related neurodegeneration diseases, such as AD, Pick's disease, frontotemporal dementia, Creutzfeldt-Jakob Disease and progressive supranuclear palsy.
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Affiliation(s)
- Xiaojun Cai
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, PR China; Shanghai Institute of Ultrasound in Medicine, The Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, 200050, Shanghai, PR China
| | - Kai Zhang
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310009, PR China
| | - Xue Xie
- Shanghai Institute of Ultrasound in Medicine, The Sixth People's Hospital Affiliated to Shanghai Jiao Tong University, 200050, Shanghai, PR China
| | - Xiandi Zhu
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310009, PR China
| | - Jin Feng
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310009, PR China
| | - Zhiming Jin
- Jiangsu Huayi Technology Limited Company, Changshu, Jiangsu, 215522, PR China
| | - Hong Zhang
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310009, PR China; Shanxi Medical University, Taiyuan, Shanxi, PR China; Key Laboratory for Biomedical Engineering of Ministry of Education, Zhejiang University, Hangzhou, China; The College of Biomedical Engineering and Instrument Science of Zhejiang University, Hangzhou, China
| | - Mei Tian
- Department of Nuclear Medicine and PET-CT Center, The Second Hospital of Zhejiang University School of Medicine, Hangzhou, Zhejiang, 310009, PR China.
| | - Hangrong Chen
- State Key Laboratory of High Performance Ceramics and Superfine Microstructure, Shanghai Institute of Ceramics, Chinese Academy of Sciences, Shanghai, 200050, PR China.
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The role of mitochondria-associated membranes in cellular homeostasis and diseases. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2019; 350:119-196. [PMID: 32138899 DOI: 10.1016/bs.ircmb.2019.11.002] [Citation(s) in RCA: 76] [Impact Index Per Article: 15.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Mitochondria and endoplasmic reticulum (ER) are fundamental in the control of cell physiology regulating several signal transduction pathways. They continuously communicate exchanging messages in their contact sites called MAMs (mitochondria-associated membranes). MAMs are specific microdomains acting as a platform for the sorting of vital and dangerous signals. In recent years increasing evidence reported that multiple scaffold proteins and regulatory factors localize to this subcellular fraction suggesting MAMs as hotspot signaling domains. In this review we describe the current knowledge about MAMs' dynamics and processes, which provided new correlations between MAMs' dysfunctions and human diseases. In fact, MAMs machinery is strictly connected with several pathologies, like neurodegeneration, diabetes and mainly cancer. These pathological events are characterized by alterations in the normal communication between ER and mitochondria, leading to deep metabolic defects that contribute to the progression of the diseases.
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Escitalopram Ameliorates Cognitive Impairment in D-Galactose-Injected Ovariectomized Rats: Modulation of JNK, GSK-3β, and ERK Signalling Pathways. Sci Rep 2019; 9:10056. [PMID: 31296935 PMCID: PMC6624366 DOI: 10.1038/s41598-019-46558-1] [Citation(s) in RCA: 28] [Impact Index Per Article: 5.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/04/2019] [Accepted: 06/27/2019] [Indexed: 12/29/2022] Open
Abstract
Though selective serotonin reuptake inhibitors (SSRIs) have been found to increase cognitive performance in some studies on patients and animal models of Alzheimer's disease (AD), other studies have reported contradictory results, and the mechanism of action has not been fully described. This study aimed to examine the effect of escitalopram, an SSRI, in an experimental model of AD and to determine the involved intracellular signalling pathways. Ovariectomized rats were administered D-galactose (150 mg/kg/day, i.p) over ten weeks to induce AD. Treatment with escitalopram (10 mg/kg/day, p.o) for four weeks, starting from the 7th week of D-galactose injection, enhanced memory performance and attenuated associated histopathological changes. Escitalopram reduced hippocampal amyloid β 42, β-secretase, and p-tau, while increasing α-secretase levels. Furthermore, it decreased tumor necrosis factor-α, nuclear factor-kappa B p65, and NADPH oxidase, while enhancing brain-derived neurotrophic factor, phospho-cAMP response element binding protein, and synaptophysin levels. Moreover, escitalopram diminished the protein expression of the phosphorylated forms of c-Jun N-terminal kinase (JNK)/c-Jun, while increasing those of phosphoinositide 3-kinase (PI3K), protein kinase B (Akt), glycogen synthase kinase-3β (GSK-3β), extracellular signal-regulated kinase (ERK) and its upstream kinases MEK and Raf-1. In conclusion, escitalopram ameliorated D-galactose/ovariectomy-induced AD-like features through modulation of PI3K/Akt/GSK-3β, Raf-1/MEK/ERK, and JNK/c-Jun pathways.
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29
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Ryu JC, Zimmer ER, Rosa-Neto P, Yoon SO. Consequences of Metabolic Disruption in Alzheimer's Disease Pathology. Neurotherapeutics 2019; 16:600-610. [PMID: 31270743 PMCID: PMC6694332 DOI: 10.1007/s13311-019-00755-y] [Citation(s) in RCA: 48] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022] Open
Abstract
Alzheimer's disease (AD) is an irreversible, progressive disease that slowly destroys cognitive function, such as thinking, remembering, and reasoning, to a level that one cannot carry out a daily living. As people live longer, the risk of developing AD has increased to 1 in 10 among people who are older than 65 and to almost 1 in 2 among those who are older than 85 according to a 2019 Alzheimer's Association report. As a most common cause of dementia, AD accounts for 60-80% of all dementia cases. AD is characterized by amyloid plaques and neurofibrillary tangles, composed of extracellular aggregates of amyloid-β peptides and intracellular aggregates of hyperphosphorylated tau, respectively. Besides plaques and tangles, AD pathology includes synaptic dysfunction including loss of synapses, inflammation, brain atrophy, and brain hypometabolism, all of which contribute to progressive cognitive decline. Recent genetic studies of sporadic cases of AD have identified a score of risk factors, as reported by Hollingworth et al. (Nat Genet 43:429-435, 2001) and Lambert et al. (Nat Genet 45:1452-1458, 2013). Of all these genes, apolipoprotein E4 (APOE4) still presents the biggest risk factor for sporadic cases of AD, as stated in Saunders et al. (Neurology 43:1467-1472, 1993): depending on whether you have 1 or 2 copies of APOE4 allele, the risk increases from 3- to 12-fold, respectively, in line with Genin et al. (Mol Psychiatry 16:903-907, 2011). Besides these genetic risk factors, having type 2 diabetes (T2D), a chronic metabolic disease, is known to increase the AD risk by at least 2-fold when these individuals age, conforming to Sims-Robinson et al. (Nat Rev Neurol 6:551-559, 2010). Diabetes is reaching a pandemic scale with over 422 million people diagnosed worldwide in 2014 according to World Health Organization. Although what proportion of these diabetic patients develop AD is not known, even if 10% of diabetic patients develop AD later in their life, it would double the number of AD patients in the world. Better understanding between T2D and AD is of paramount of importance for the future. The goal of this review is to examine our current understanding on metabolic dysfunction in AD, so that a potential target can be identified in the near future.
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Affiliation(s)
- J C Ryu
- Department of Biological Chemistry & Pharmacology, Ohio State University, Columbus, OH, USA
| | - E R Zimmer
- Department of Pharmacology, UFRGS, Porto Alegre, Brazil
- Graduate Program in Biological Sciences: Biochemistry, Universidade Federal do Rio Grande do Sul (UFRGS), Porto Alegre, Brazil
- Graduate Program in Biological Sciences: Pharmacology and Therapeutics, UFRGS, Porto Alegre, Brazil
- Brain Institute of Rio Grande do Sul (BraIns), Pontifical Catholic University of Rio Grande do Sul, Porto Alegre, Brazil
| | - P Rosa-Neto
- Montreal Neurological Institute, Montreal, Canada
| | - S O Yoon
- Department of Biological Chemistry & Pharmacology, Ohio State University, Columbus, OH, USA.
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30
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Wang Q, Hu J, Liu Y, Li J, Liu B, Li M, Lou S. Aerobic Exercise Improves Synaptic-Related Proteins of Diabetic Rats by Inhibiting FOXO1/NF-κB/NLRP3 Inflammatory Signaling Pathway and Ameliorating PI3K/Akt Insulin Signaling Pathway. J Mol Neurosci 2019; 69:28-38. [DOI: 10.1007/s12031-019-01302-2] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/05/2019] [Accepted: 03/14/2019] [Indexed: 01/08/2023]
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31
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Sharma N, Tramutola A, Lanzillotta C, Arena A, Blarzino C, Cassano T, Butterfield DA, Di Domenico F, Perluigi M, Barone E. Loss of biliverdin reductase-A favors Tau hyper-phosphorylation in Alzheimer's disease. Neurobiol Dis 2019; 125:176-189. [PMID: 30738142 DOI: 10.1016/j.nbd.2019.02.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 9.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/13/2018] [Revised: 01/31/2019] [Accepted: 02/04/2019] [Indexed: 01/16/2023] Open
Abstract
Hyper-active GSK-3β favors Tau phosphorylation during the progression of Alzheimer's disease (AD). Akt is one of the main kinases inhibiting GSK-3β and its activation occurs in response to neurotoxic stimuli including, i.e., oxidative stress. Biliverdin reductase-A (BVR-A) is a scaffold protein favoring the Akt-mediated inhibition of GSK-3β. Reduced BVR-A levels along with increased oxidative stress were observed early in the hippocampus of 3xTg-AD mice (at 6 months), thus suggesting that loss of BVR-A could be a limiting factor in the oxidative stress-induced Akt-mediated inhibition of GSK-3β in AD. We evaluated changes of BVR-A, Akt, GSK-3β, oxidative stress and Tau phosphorylation levels: (a) in brain from young (6-months) and old (12-months) 3xTg-AD mice; and (b) in post-mortem inferior parietal lobule (IPL) samples from amnestic mild cognitive impairment (MCI), from AD and from age-matched controls. Furthermore, similar analyses were performed in vitro in cells lacking BVR-A and treated with H2O2. Reduced BVR-A levels along with: (a) increased oxidative stress; (b) reduced GSK-3β inhibition; and (c) increased Tau Ser404 phosphorylation (target of GSK-3β activity) without changes of Akt activation in young mice, were observed. Similar findings were obtained in MCI, consistent with the notion that this is a molecular mechanism disrupted in humans. Interestingly, cells lacking BVR-A and treated with H2O2 showed reduced GSK-3β inhibition and increased Tau Ser404 phosphorylation, which resulted from a defect of Akt and GSK-3β physical interaction. Reduced levels of Akt/GSK-3β complex were confirmed in both young 3xTg-AD and MCI brain. We demonstrated that loss of BVR-A impairs the neuroprotective Akt-mediated inhibition of GSK-3β in response to oxidative stress, thus contributing to Tau hyper-phosphorylation in early stage AD. Such changes potential provide promising therapeutic targets for this devastating disorder.
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Affiliation(s)
- Nidhi Sharma
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, Roma 00185, Italy
| | - Antonella Tramutola
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, Roma 00185, Italy
| | - Chiara Lanzillotta
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, Roma 00185, Italy
| | - Andrea Arena
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, Roma 00185, Italy
| | - Carla Blarzino
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, Roma 00185, Italy
| | - Tommaso Cassano
- Department of Clinical and Experimental Medicine, University of Foggia, Via L. Pinto, Foggia 71122, Italy
| | - D Allan Butterfield
- Department of Chemistry, Markey Cancer Center, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
| | - Fabio Di Domenico
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, Roma 00185, Italy
| | - Marzia Perluigi
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, Roma 00185, Italy
| | - Eugenio Barone
- Department of Biochemical Sciences "A. Rossi-Fanelli", Sapienza University of Rome, Piazzale A. Moro 5, Roma 00185, Italy.
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The ProNGF/p75NTR pathway induces tau pathology and is a therapeutic target for FTLD-tau. Mol Psychiatry 2018; 23:1813-1824. [PMID: 29867188 DOI: 10.1038/s41380-018-0071-z] [Citation(s) in RCA: 33] [Impact Index Per Article: 5.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/30/2017] [Revised: 01/26/2018] [Accepted: 03/26/2018] [Indexed: 11/09/2022]
Abstract
Tau pathology is characterized as a form of frontotemporal lobar degeneration (FTLD) known as FTLD-tau. The underlying pathogenic mechanisms are not known and no therapeutic interventions are currently available. Here, we report that the neurotrophin receptor p75NTR plays a critical role in the pathogenesis of FTLD-tau. The expression of p75NTR and the precursor of nerve growth factor (proNGF) were increased in the brains of FTLD-tau patients and mice (P301L transgenic). ProNGF-induced tau phosphorylation via p75NTR in vitro, which was associated with the AKT/glycogen synthase kinase (GSK)3β pathway. Genetic reduction of p75NTR in P301L mice rescued the memory deficits, alleviated tau hyperphosphorylation and restored the activity of the AKT/GSK3β pathway. Treatment of the P301L mice with the soluble p75NTR extracellular domain (p75ECD-Fc), which can antagonize neurotoxic ligands of p75NTR, effectively improved memory behavior and suppressed tau pathology. This suggests that p75NTR plays a crucial role in tau paGSKthology and represents a potential druggable target for FTLD-tau and related tauopathies.
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Cheng W, Chen W, Wang P, Chu J. Asiatic acid protects differentiated PC12 cells from Aβ 25-35-induced apoptosis and tau hyperphosphorylation via regulating PI3K/Akt/GSK-3β signaling. Life Sci 2018; 208:96-101. [PMID: 30017668 DOI: 10.1016/j.lfs.2018.07.016] [Citation(s) in RCA: 34] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/10/2018] [Revised: 07/05/2018] [Accepted: 07/10/2018] [Indexed: 10/28/2022]
Abstract
Amyloid β (Aβ) peptide can cause neurotoxicity in Alzheimer's disease (AD). The main purpose of the present study is to investigate the protective role of asiatic acid (AA) against Aβ25-35-induced neurotoxicity in neuronally differentiated PC12 cells. Differentiated PC12 cells were pretreated with 5, 10 or 20 μM AA before treatment with 20 μM Aβ25-35. The viability and apoptosis of differentiated PC12 cells were determined by MTT assay and Annexin V-FITC/PI double staining, respectively. The mitochondrial membrane potential (MMP) of differentiated PC12 cells was analyzed by JC-1 staining. The expression levels of proteins were detected by western blot analysis. We found that AA significantly increased the viability of differentiated PC12 cells but attenuated the mitochondria-mediated apoptosis dose-dependently when challenging with Aβ25-35. Besides, the results of western blot analysis showed that AA prevented IκBα degradation and p65 nuclear translocation, and promoted the phosphorylation of Akt and GSK-3β in Aβ25-35-treated differentiated PC12 cells. Moreover, LY294002, a specific PI3K inhibitor, was found to abolish the beneficial effects of AA on Aβ25-35-induced apoptosis and tau protein hyperphosphorylation. Our findings demonstrated that AA protects differentiated PC12 cells from Aβ25-35-induced apoptosis and tau protein hyperphosphorylation, which might be partially mediated by the activation of the PI3K/Akt/GSK-3β signaling pathway.
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Affiliation(s)
- Wenjing Cheng
- Department of Neurology, No.1 People's Hospital of Jining City, Jining, Shandong, China
| | - Weimei Chen
- Department of Neurology, No.1 People's Hospital of Jining City, Jining, Shandong, China
| | - Peng Wang
- Department of Neurology, No.1 People's Hospital of Jining City, Jining, Shandong, China
| | - Jianfeng Chu
- Department of Neurology, No.1 People's Hospital of Jining City, Jining, Shandong, China.
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Baranowski BJ, Bott KN, MacPherson REK. Evaluation of neuropathological effects of a high-fat high-sucrose diet in middle-aged male C57BL6/J mice. Physiol Rep 2018; 6:e13729. [PMID: 29890051 PMCID: PMC5995310 DOI: 10.14814/phy2.13729] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/14/2018] [Revised: 05/14/2018] [Accepted: 05/15/2018] [Indexed: 12/21/2022] Open
Abstract
Metabolic dysfunction related to diet-induced obesity has recently been linked to the pathogenesis of sporadic Alzheimer's disease (AD). However, the underlying mechanisms linking obesity and AD remain unclear. The purpose of this study was to examine early alterations in brain insulin signaling, inflammatory/stress markers, and energetic stress in a model of diet-induced obesity during middle age. Male C57BL/6J mice were randomized to either a control diet (AGE n = 12) or high-fat and sucrose diet (AGE-HFS n = 12) for 13-weeks from 20-weeks of age. Prefrontal cortex and hippocampal samples were collected at 20-weeks of age (BSL n = 11) and at 33-weeks of age (AGE and AGE-HFS). The HFS diet resulted in increased body weight (30%; P = 0.0001), increased %fat mass (28%; P = 0.0001), and decreased %lean mass (33%; P = 0.0001) compared to aged controls. In the prefrontal cortex, AGE-HFS resulted in increased 5' adenosine monophosphate - activated protein kinase (AMPK) phosphorylation (P = 0.045). In the hippocampus, AGE-HFS resulted in increased extracellular signal-regulated kinase (ERK) and c-Jun N-terminal kinase (JNK) phosphorylation and protein kinase B (Akt) serine473 and glycogen synthase kinase (GSK) phosphorylation (P < 0.05). Results from this study demonstrate that aging combined with a HFS diet results in increased inflammation (pERK and pJNK) and energetic stress (pAMPK) in the hippocampus and prefrontal cortex, respectively. Together these novel results provide important information for future targets in early AD pathogenesis.
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Benedict C, Grillo CA. Insulin Resistance as a Therapeutic Target in the Treatment of Alzheimer's Disease: A State-of-the-Art Review. Front Neurosci 2018; 12:215. [PMID: 29743868 PMCID: PMC5932355 DOI: 10.3389/fnins.2018.00215] [Citation(s) in RCA: 61] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2017] [Accepted: 03/19/2018] [Indexed: 01/10/2023] Open
Abstract
Research in animals and humans has shown that type 2 diabetes and its prodromal state, insulin resistance, promote major pathological hallmarks of Alzheimer's disease (AD), such as the formation of amyloid plaques and neurofibrillary tangles (NFT). Worrisomely, dysregulated amyloid beta (Aβ) metabolism has also been shown to promote central nervous system insulin resistance; although the role of tau metabolism remains controversial. Collectively, as proposed in this review, these findings suggest the existence of a mechanistic interplay between AD pathogenesis and disrupted insulin signaling. They also provide strong support for the hypothesis that pharmacologically restoring brain insulin signaling could represent a promising strategy to curb the development and progression of AD. In this context, great hopes have been attached to the use of intranasal insulin. This drug delivery method increases cerebrospinal fluid concentrations of insulin in the absence of peripheral side effects, such as hypoglycemia. With this in mind, the present review will also summarize current knowledge on the efficacy of intranasal insulin to mitigate major pathological symptoms of AD, i.e., cognitive impairment and deregulation of Aβ and tau metabolism.
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Affiliation(s)
| | - Claudia A Grillo
- Department of Pharmacology, Physiology and Neuroscience, University of South Carolina-School of Medicine, Columbia, SC, United States
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Lee HK, Kwon B, Lemere CA, de la Monte S, Itamura K, Ha AY, Querfurth HW. mTORC2 (Rictor) in Alzheimer's Disease and Reversal of Amyloid-β Expression-Induced Insulin Resistance and Toxicity in Rat Primary Cortical Neurons. J Alzheimers Dis 2018; 56:1015-1036. [PMID: 28035937 DOI: 10.3233/jad-161029] [Citation(s) in RCA: 25] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/11/2023]
Abstract
Mammalian target of rapamycin complex 1 (mTORC1), a nutrient sensor and central controller of cell growth and proliferation, is altered in various models of Alzheimer's disease (AD). Even less studied or understood in AD is mammalian target of rapamycin complex 2 (mTORC2) that influences cellular metabolism, in part through the regulations of Akt/PKB and SGK. Dysregulation of insulin/PI3K/Akt signaling is another important feature of AD pathogenesis. We found that both total mTORC1 and C2 protein levels and individual C1 and C2 enzymatic activities were decreased in human AD brain samples. In two rodent AD models, mTORC1 and C2 activities were also decreased. In a neuronal culture model of AD characterized by accumulation of cellular amyloid-β (Aβ)42, mTORC1 activity was reduced. Autophagic vesicles and markers were correspondingly increased and new protein synthesis was inhibited, consistent with mTORC1 hypofunction. Interestingly, mTORC2 activity in neural culture seemed resistant to the effects of intracellular amyloid. In various cell lines, Aβ expression provoked insulin resistance, characterized by inhibition of stimulated Akt phosphorylation, and an increase in negative mTORC1 regular, p-AMPK, itself a nutrient sensor. Rapamycin decreased phospho-mTOR and to lesser degree p-Rictor. This further suppression of mTORC1 activity protected cells from Aβ-induced toxicity and insulin resistance. More striking, Rictor over-expression fully reversed the Aβ-effects on primary neuronal cultures. Finally, using in vitro assay, Rictor protein addition completely overcame oligomeric Aβ-induced inhibition of the PDK-Akt activation step. We conclude that striking a new balance by restoring mTORC2 abundance and/or inhibition of mTORC1 has therapeutic potential in AD.
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Affiliation(s)
- Han-Kyu Lee
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Bumsup Kwon
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Cynthia A Lemere
- Ann Romney Center for Neurologic Diseases, Brigham and Women's Hospital and Harvard Medical School, Boston, MA, USA
| | - Suzanne de la Monte
- Department of Pathology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Kyohei Itamura
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Austin Y Ha
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
| | - Henry W Querfurth
- Department of Neurology, Rhode Island Hospital and Brown University Warren Alpert Medical School, Providence, RI, USA
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Brain insulin resistance in type 2 diabetes and Alzheimer disease: concepts and conundrums. Nat Rev Neurol 2018; 14:168-181. [PMID: 29377010 DOI: 10.1038/nrneurol.2017.185] [Citation(s) in RCA: 882] [Impact Index Per Article: 147.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/06/2023]
Abstract
Considerable overlap has been identified in the risk factors, comorbidities and putative pathophysiological mechanisms of Alzheimer disease and related dementias (ADRDs) and type 2 diabetes mellitus (T2DM), two of the most pressing epidemics of our time. Much is known about the biology of each condition, but whether T2DM and ADRDs are parallel phenomena arising from coincidental roots in ageing or synergistic diseases linked by vicious pathophysiological cycles remains unclear. Insulin resistance is a core feature of T2DM and is emerging as a potentially important feature of ADRDs. Here, we review key observations and experimental data on insulin signalling in the brain, highlighting its actions in neurons and glia. In addition, we define the concept of 'brain insulin resistance' and review the growing, although still inconsistent, literature concerning cognitive impairment and neuropathological abnormalities in T2DM, obesity and insulin resistance. Lastly, we review evidence of intrinsic brain insulin resistance in ADRDs. By expanding our understanding of the overlapping mechanisms of these conditions, we hope to accelerate the rational development of preventive, disease-modifying and symptomatic treatments for cognitive dysfunction in T2DM and ADRDs alike.
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38
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Yang S, Pascual-Guiral S, Ponce R, Giménez-Llort L, Baltrons MA, Arancio O, Palacio JR, Clos VM, Yuste VJ, Bayascas JR. Reducing the Levels of Akt Activation by PDK1 Knock-in Mutation Protects Neuronal Cultures against Synthetic Amyloid-Beta Peptides. Front Aging Neurosci 2018; 9:435. [PMID: 29358916 PMCID: PMC5766684 DOI: 10.3389/fnagi.2017.00435] [Citation(s) in RCA: 22] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/29/2017] [Accepted: 12/15/2017] [Indexed: 12/16/2022] Open
Abstract
The Akt kinase has been widely assumed for years as a key downstream effector of the PI3K signaling pathway in promoting neuronal survival. This notion was however challenged by the finding that neuronal survival responses were still preserved in mice with reduced Akt activity. Moreover, here we show that the Akt signaling is elevated in the aged brain of two different mice models of Alzheimer Disease. We manipulate the rate of Akt stimulation by employing knock-in mice expressing a mutant form of PDK1 (phosphoinositide-dependent protein kinase 1) with reduced, but not abolished, ability to activate Akt. We found increased membrane localization and activity of the TACE/ADAM17 α-secretase in the brain of the PDK1 mutant mice with concomitant TNFR1 processing, which provided neurons with resistance against TNFα-induced neurotoxicity. Opposite to the Alzheimer Disease transgenic mice, the PDK1 knock-in mice exhibited an age-dependent attenuation of the unfolding protein response, which protected the mutant neurons against endoplasmic reticulum stressors. Moreover, these two mechanisms cooperatively provide the mutant neurons with resistance against amyloid-beta oligomers, and might singularly also contribute to protect these mice against amyloid-beta pathology.
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Affiliation(s)
- Shaobin Yang
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Sònia Pascual-Guiral
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Rebeca Ponce
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Lydia Giménez-Llort
- Departament de Psiquiatria i Medicina Legal, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - María A. Baltrons
- Departament de Bioquímica i Biologia Molecular, Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Ottavio Arancio
- Department of Pathology, The Taub Institute for Research on Alzheimer's Disease and the Aging Brain, Columbia University, New York, NY, United States
| | - Jose R. Palacio
- Departament de Biologia Cel.lular, Fisiologia i Immunologia, Institute of Biotechnology and Biomedicine, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Victoria M. Clos
- Departament de Farmacologia, Terapèutica i Toxicologia, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Victor J. Yuste
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
| | - Jose R. Bayascas
- Unitat de Bioquímica de Medicina, Departament de Bioquímica i Biologia Molecular, Institut de Neurociències, Universitat Autònoma de Barcelona, Barcelona, Spain
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Escitalopram attenuates β-amyloid-induced tau hyperphosphorylation in primary hippocampal neurons through the 5-HT1A receptor mediated Akt/GSK-3β pathway. Oncotarget 2017; 7:13328-39. [PMID: 26950279 PMCID: PMC4924645 DOI: 10.18632/oncotarget.7798] [Citation(s) in RCA: 41] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2016] [Accepted: 02/18/2016] [Indexed: 11/25/2022] Open
Abstract
Tau hyperphosphorylation is an important pathological feature of Alzheimer's disease (AD). To investigate whether escitalopram could inhibit amyloid-β (Aβ)-induced tau hyperphosphorylation and the underlying mechanisms, we treated the rat primary hippocampal neurons with Aβ1-42 and examined the effect of escitalopram on tau hyperphosphorylation. Results showed that escitalopram decreased Aβ1-42-induced tau hyperphosphorylation. In addition, escitalopram activated the Akt/GSK-3β pathway, and the PI3K inhibitor LY294002 blocked the attenuation of tau hyperphosphorylation induced by escitalopram. Moreover, the 5-HT1A receptor agonist 8-OH-DPAT also activated the Akt/GSK-3β pathway and decreased Aβ1-42-induced tau hyperphosphorylation. Furthermore, the 5-HT1A receptor antagonist WAY-100635 blocked the activation of Akt/GSK-3β pathway and the attenuation of tau hyperphosphorylation induced by escitalopram. Finally, escitalopram improved Aβ1-42 induced impairment of neurite outgrowth and spine density, and reversed Aβ1-42 induced reduction of synaptic proteins. Our results demonstrated that escitalopram attenuated Aβ1-42-induced tau hyperphosphorylation in primary hippocampal neurons through the 5-HT1A receptor mediated Akt/GSK-3β pathway.
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40
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Sun J, Zhang X, Wang C, Teng Z, Li Y. Curcumin Decreases Hyperphosphorylation of Tau by Down-Regulating Caveolin-1/GSK-3β in N2a/APP695swe Cells and APP/PS1 Double Transgenic Alzheimer’s Disease Mice. THE AMERICAN JOURNAL OF CHINESE MEDICINE 2017; 45:1667-1682. [DOI: 10.1142/s0192415x17500902] [Citation(s) in RCA: 32] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Caveolin-1, the marker protein of membranal caveolae, is not only involved in cholesterol regulation, but also participates in the cleavage of amyloid [Formula: see text]-protein precursor (APP) and the generation of [Formula: see text]-amyloid peptide. It has been reported to be tightly related with Tau. In our previous studies, curcumin has been confirmed to play a neuroprotective role in Alzheimer’s disease (AD), but its effects on Caveolin-1, Tau and their correlation, and the mechanism is still unknown. As such, in the present study, N2a/WT cells, N2a/APP695swe cell and six-month-old APP/PS1 double transgenic mice were enrolled. After curcumin treatment, the expression of Caveolin-1, Tau and their relationship was detected, and the potential mechanisms were explored. The results showed that in the N2a/APP695swe cells, curcumin not only decreased the number of caveolae, but also made their membrane to be thinner; and curcumin could decreased the expression of phosphorylated Tau (P-Tau(ser404)/Tau) and Caveolin-1 ([Formula: see text]), but the expression of phosphorylated GSK-3[Formula: see text] (P-GSK-3[Formula: see text]/GSK-3[Formula: see text] was increased ([Formula: see text]). In APP/PS1 transgenic mice, the same results were observed. Taken together, our data suggest that curcumin may play an important role in AD via reducing Caveolin-1, inactivating GSK-3[Formula: see text] and inhibiting the abnormal excessive phosphorylation of Tau, which will provide a new theory for AD treatment with curcumin.
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Affiliation(s)
- Jieyun Sun
- Department of Pathology, Chongqing Medical University, Chongqing 400016, P. R. China
- Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, P. R. China
| | - Xiong Zhang
- Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, P. R. China
| | - Chen Wang
- Department of Pathology, Chongqing Medical University, Chongqing 400016, P. R. China
- Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, P. R. China
| | - Zhipeng Teng
- Department of Pathology, Chongqing Medical University, Chongqing 400016, P. R. China
- Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, P. R. China
| | - Yu Li
- Department of Pathology, Chongqing Medical University, Chongqing 400016, P. R. China
- Institute of Neuroscience, Chongqing Medical University, Chongqing 400016, P. R. China
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41
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Mohamed A, Viveiros A, Williams K, Posse de Chaves E. Aβ inhibits SREBP-2 activation through Akt inhibition. J Lipid Res 2017; 59:1-13. [PMID: 29122977 PMCID: PMC5748492 DOI: 10.1194/jlr.m076703] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/03/2017] [Revised: 10/21/2017] [Indexed: 12/20/2022] Open
Abstract
We previously demonstrated that oligomeric amyloid β42 (oAβ42) inhibits the mevalonate pathway impairing cholesterol synthesis and protein prenylation. Enzymes of the mevalonate pathway are regulated by the transcription factor SREBP-2. Here, we show that in several neuronal types challenged with oAβ42, SREBP-2 activation is reduced. Moreover, SREBP-2 activation is also decreased in the brain cortex of the Alzheimer's disease (AD) mouse model, TgCRND8, suggesting that SREBP-2 may be affected in vivo early in the disease. We demonstrate that oAβ42 does not affect enzymatic cleavage of SREBP-2 per se, but may impair SREBP-2 transport from the endoplasmic reticulum (ER) to the Golgi. Trafficking of SREBP-2 from the ER to the Golgi requires protein kinase B (Akt) activation. oAβ42 significantly reduces Akt phosphorylation and this decrease is responsible for the decline in SREBP-2 activation. Overexpression of constitutively active Akt prevents the effect of oAβ42 on SREBP-2 and the downstream inhibition of cholesterol synthesis and protein prenylation. Our work provides a novel mechanistic link between Aβ and the mevalonate pathway, which will impact the views on issues related to cholesterol, isoprenoids, and statins in AD. We also identify SREBP-2 as an indirect target of Akt in neurons, which may play a role in the cross-talk between AD and diabetes.
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Affiliation(s)
- Amany Mohamed
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Anissa Viveiros
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Kathleen Williams
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
| | - Elena Posse de Chaves
- Department of Pharmacology and Neuroscience and Mental Health Institute, University of Alberta, Edmonton, Alberta, Canada
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Short-Term Fructose Feeding Induces Inflammation and Oxidative Stress in the Hippocampus of Young and Adult Rats. Mol Neurobiol 2017; 55:2869-2883. [PMID: 28455700 DOI: 10.1007/s12035-017-0518-2] [Citation(s) in RCA: 51] [Impact Index Per Article: 7.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/22/2016] [Accepted: 04/04/2017] [Indexed: 10/19/2022]
Abstract
The drastic increase in the consumption of fructose encouraged the research to focus on its effects on brain physio-pathology. Although young and adults differ largely by their metabolic and physiological profiles, most of the previous studies investigated brain disturbances induced by long-term fructose feeding in adults. Therefore, we investigated whether a short-term consumption of fructose (2 weeks) produces early increase in specific markers of inflammation and oxidative stress in the hippocampus of young and adult rats. After the high-fructose diet, plasma lipopolysaccharide and tumour necrosis factor (TNF)-alpha were found significantly increased in parallel with hippocampus inflammation, evidenced by a significant rise in TNF-alpha and glial fibrillar acidic protein concentrations in both the young and adult groups. The fructose-induced inflammatory condition was associated with brain oxidative stress, as increased levels of lipid peroxidation and nitro-tyrosine were detected in the hippocampus. The degree of activation of the protein kinase B, extracellular signal-regulated kinase 1/2, and insulin receptor substrate 1 pathways found in the hippocampus after fructose feeding indicates that the detrimental effects of the fructose-rich diet might largely depend on age. Mitochondrial function in the hippocampus, together with peroxisome proliferator-activated receptor gamma coactivator 1-alpha content, was found significantly decreased in fructose-treated adult rats. In vitro studies with BV-2 microglial cells confirmed that fructose treatment induces TNF-alpha production as well as oxidative stress. In conclusion, these results suggest that unbalanced diet, rich in fructose, may be highly deleterious in young people as in adults and must be strongly discouraged for the prevention of diet-associated neuroinflammation and neurological diseases.
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43
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Ng RCL, Chan KH. Potential Neuroprotective Effects of Adiponectin in Alzheimer's Disease. Int J Mol Sci 2017; 18:E592. [PMID: 28282917 PMCID: PMC5372608 DOI: 10.3390/ijms18030592] [Citation(s) in RCA: 47] [Impact Index Per Article: 6.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/23/2016] [Revised: 02/20/2017] [Accepted: 02/28/2017] [Indexed: 12/11/2022] Open
Abstract
The adipocyte-secreted protein adiponectin (APN) has several protective functions in the peripheral tissues including insulin sensitizing, anti-inflammatory and anti-oxidative effects that may benefit neurodegenerative diseases such as Alzheimer's disease (AD). In addition, dysregulation of cerebral insulin sensitivities and signaling activities have been implicated in AD. Emerging insights into the mechanistic roles of adiponectin and AD highlight the potential therapeutic effects for AD through insulin signaling.
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Affiliation(s)
- Roy Chun-Laam Ng
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
- Research Center of Heart, Brain, Hormone and Healthy Aging, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
| | - Koon-Ho Chan
- Department of Medicine, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
- Research Center of Heart, Brain, Hormone and Healthy Aging, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
- Hong Kong University Alzheimer's Disease Research Network, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
- Neuroimmunology and Neuroinflammation Research Laboratory, LKS Faculty of Medicine, The University of Hong Kong, Hong Kong SAR, China.
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44
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Cabré R, Naudí A, Dominguez-Gonzalez M, Ayala V, Jové M, Mota-Martorell N, Piñol-Ripoll G, Gil-Villar MP, Rué M, Portero-Otín M, Ferrer I, Pamplona R. Sixty years old is the breakpoint of human frontal cortex aging. Free Radic Biol Med 2017; 103:14-22. [PMID: 27979658 DOI: 10.1016/j.freeradbiomed.2016.12.010] [Citation(s) in RCA: 25] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/25/2016] [Revised: 11/18/2016] [Accepted: 12/07/2016] [Indexed: 11/25/2022]
Abstract
Human brain aging is the physiological process which underlies as cause of cognitive decline in the elderly and the main risk factor for neurodegenerative diseases such as Alzheimer's disease. Human neurons are functional throughout a healthy adult lifespan, yet the mechanisms that maintain function and protect against neurodegenerative processes during aging are unknown. Here we show that protein oxidative and glycoxidative damage significantly increases during human brain aging, with a breakpoint at 60 years old. This trajectory is coincident with a decrease in the content of the mitochondrial respiratory chain complex I-IV. We suggest that the deterioration in oxidative stress homeostasis during aging induces an adaptive response of stress resistance mechanisms based on the sustained expression of REST, and increased or decreased expression of Akt and mTOR, respectively, over the adult lifespan in order to preserve cell neural survival and function.
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Affiliation(s)
- Rosanna Cabré
- Department of Experimental Medicine, University of Lleida-Institute for Research in Biomedicine of Lleida (UdL-IRBLleida), E-25198 Lleida, Spain.
| | - Alba Naudí
- Department of Experimental Medicine, University of Lleida-Institute for Research in Biomedicine of Lleida (UdL-IRBLleida), E-25198 Lleida, Spain.
| | - Mayelin Dominguez-Gonzalez
- Institute of Neuropathology, Department of Pathology and Experimental Therapeutics, University of Barcelona, E-08908 L'Hospitalet de Llobregat, Barcelona, Spain.
| | - Victòria Ayala
- Department of Experimental Medicine, University of Lleida-Institute for Research in Biomedicine of Lleida (UdL-IRBLleida), E-25198 Lleida, Spain.
| | - Mariona Jové
- Department of Experimental Medicine, University of Lleida-Institute for Research in Biomedicine of Lleida (UdL-IRBLleida), E-25198 Lleida, Spain.
| | - Natalia Mota-Martorell
- Department of Experimental Medicine, University of Lleida-Institute for Research in Biomedicine of Lleida (UdL-IRBLleida), E-25198 Lleida, Spain.
| | | | | | - Montserrat Rué
- Department of Basic Medical Sciences, University of Lleida-Institute for Research in Biomedicine of Lleida (UdL-IRBLleida), E-25198 Lleida, Spain.
| | - Manuel Portero-Otín
- Department of Experimental Medicine, University of Lleida-Institute for Research in Biomedicine of Lleida (UdL-IRBLleida), E-25198 Lleida, Spain.
| | - Isidre Ferrer
- Institute of Neuropathology, Department of Pathology and Experimental Therapeutics, University of Barcelona, E-08908 L'Hospitalet de Llobregat, Barcelona, Spain; Center for Biomedical Research on Neurodegenerative Diseases (CIBERNED), ISCIII, Spain.
| | - Reinald Pamplona
- Department of Experimental Medicine, University of Lleida-Institute for Research in Biomedicine of Lleida (UdL-IRBLleida), E-25198 Lleida, Spain.
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45
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Lee HJ, Ryu JM, Jung YH, Lee SJ, Kim JY, Lee SH, Hwang IK, Seong JK, Han HJ. High glucose upregulates BACE1-mediated Aβ production through ROS-dependent HIF-1α and LXRα/ABCA1-regulated lipid raft reorganization in SK-N-MC cells. Sci Rep 2016; 6:36746. [PMID: 27829662 PMCID: PMC5103190 DOI: 10.1038/srep36746] [Citation(s) in RCA: 50] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/13/2016] [Accepted: 10/20/2016] [Indexed: 01/07/2023] Open
Abstract
There is an accumulation of evidence indicating that the risk of Alzheimer’s disease is associated with diabetes mellitus, an indicator of high glucose concentrations in blood plasma. This study investigated the effect of high glucose on BACE1 expression and amyloidogenesis in vivo, and we present details of the mechanism associated with those effects. Our results, using ZLC and ZDF rat models, showed that ZDF rats have high levels of amyloid-beta (Aβ), phosphorylated tau, BACE1, and APP-C99. In vitro result with mouse hippocampal neuron and SK-N-MC, high glucose stimulated Aβ secretion and apoptosis in a dose-dependent manner. In addition, high glucose increased BACE1 and APP-C99 expressions, which were reversed by a reactive oxygen species (ROS) scavenger. Indeed, high glucose increased intracellular ROS levels and HIF-1α expression, associated with regulation of BACE1 and Liver X Receptor α (LXRα). In addition, high glucose induced ATP-binding cassette transporter A1 (ABCA1) down-regulation, was associated with LXR-induced lipid raft reorganization and BACE1 localization on the lipid raft. Furthermore, silencing of BACE1 expression was shown to regulate Aβ secretion and apoptosis of SK-N-MC. In conclusion, high glucose upregulates BACE1 expression and activity through HIF-1α and LXRα/ABCA1-regulated lipid raft reorganization, leading to Aβ production and apoptosis of SK-N-MC.
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Affiliation(s)
- Hyun Jik Lee
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National University, Seoul 08826, Korea
| | - Jung Min Ryu
- Department of Veterinary Physiology, College of Veterinary Medicine, Chonnam National University, Gwangju 61186, Korea
| | - Young Hyun Jung
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National University, Seoul 08826, Korea
| | - Sei-Jung Lee
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National University, Seoul 08826, Korea
| | - Jeong Yeon Kim
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National University, Seoul 08826, Korea
| | - Sang Hun Lee
- Medical Science Research Institute, Soonchunhyang University Seoul Hospital, Seoul, Republic of Korea.,Department of Biochemistry, Soonchunhyang University College of Medicine, Cheonan, 330-930, Republic of Korea
| | - In Koo Hwang
- BK21 PLUS Program for Creative Veterinary Science Research, and Research Institute for Veterinary Science; Seoul National University and Korea Mouse Phenotyping Center (KMPC), Seoul, Korea.,Department of Anatomy and Cell Biology; Korea Mouse Phenotyping Center (KMPC); College of Veterinary Medicine; Seoul National University, Seoul, Korea
| | - Je Kyung Seong
- BK21 PLUS Program for Creative Veterinary Science Research, and Research Institute for Veterinary Science; Seoul National University and Korea Mouse Phenotyping Center (KMPC), Seoul, Korea.,Department of Anatomy and Cell Biology; Korea Mouse Phenotyping Center (KMPC); College of Veterinary Medicine; Seoul National University, Seoul, Korea
| | - Ho Jae Han
- Department of Veterinary Physiology, College of Veterinary Medicine, Research Institute for Veterinary Science and BK21 PLUS Program for Creative Veterinary Science Research Center, Seoul National University, Seoul 08826, Korea
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46
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Stanley M, Macauley SL, Holtzman DM. Changes in insulin and insulin signaling in Alzheimer's disease: cause or consequence? J Exp Med 2016; 213:1375-85. [PMID: 27432942 PMCID: PMC4986537 DOI: 10.1084/jem.20160493] [Citation(s) in RCA: 143] [Impact Index Per Article: 17.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/05/2016] [Accepted: 06/20/2016] [Indexed: 12/30/2022] Open
Abstract
Stanley and colleagues explore whether changes in insulin levels and insulin
signaling are a cause or consequence of AD. Individuals with type 2 diabetes have an increased risk for developing
Alzheimer’s disease (AD), although the causal relationship remains poorly
understood. Alterations in insulin signaling (IS) are reported in the AD brain.
Moreover, oligomers/fibrils of amyloid-β (Aβ) can lead to neuronal
insulin resistance and intranasal insulin is being explored as a potential therapy
for AD. Conversely, elevated insulin levels (ins) are found in AD patients and high
insulin has been reported to increase Aβ levels and tau phosphorylation, which
could exacerbate AD pathology. Herein, we explore whether changes in ins and IS are a
cause or consequence of AD.
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Affiliation(s)
- Molly Stanley
- Department of Neurology, Hope Center for Neurological Disorders, Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO
| | - Shannon L Macauley
- Department of Neurology, Hope Center for Neurological Disorders, Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO
| | - David M Holtzman
- Department of Neurology, Hope Center for Neurological Disorders, Charles F. and Joanne Knight Alzheimer's Disease Research Center, Washington University School of Medicine, St. Louis, MO
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47
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Sajan M, Hansen B, Ivey R, Sajan J, Ari C, Song S, Braun U, Leitges M, Farese-Higgs M, Farese RV. Brain Insulin Signaling Is Increased in Insulin-Resistant States and Decreases in FOXOs and PGC-1α and Increases in Aβ1-40/42 and Phospho-Tau May Abet Alzheimer Development. Diabetes 2016; 65:1892-903. [PMID: 26895791 PMCID: PMC4915579 DOI: 10.2337/db15-1428] [Citation(s) in RCA: 54] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/14/2015] [Accepted: 02/08/2016] [Indexed: 12/16/2022]
Abstract
Increased coexistence of Alzheimer disease (AD) and type 2 diabetes mellitus (T2DM) suggests that insulin resistance abets neurodegenerative processes, but linkage mechanisms are obscure. Here, we examined insulin signaling factors in brains of insulin-resistant high-fat-fed mice, ob/ob mice, mice with genetically impaired muscle glucose transport, and monkeys with diet-dependent long-standing obesity/T2DM. In each model, the resting/basal activities of insulin-regulated brain protein kinases, Akt and atypical protein kinase C (aPKC), were maximally increased. Moreover, Akt hyperactivation was accompanied by hyperphosphorylation of substrates glycogen synthase kinase-3β and mammalian target of rapamycin and FOXO proteins FOXO1, FOXO3A, and FOXO4 and decreased peroxisome proliferator-activated receptor γ coactivator-1α (PGC-1α) expression. Akt hyperactivation was confirmed in individual neurons of anterocortical and hippocampal regions that house cognition/memory centers. Remarkably, β-amyloid (Aβ1-40/42) peptide levels were as follows: increased in the short term by insulin in normal mice, increased basally in insulin-resistant mice and monkeys, and accompanied by diminished amyloid precursor protein in monkeys. Phosphorylated tau levels were increased in ob/ob mice and T2DM monkeys. Importantly, with correction of hyperinsulinemia by inhibition of hepatic aPKC and improvement in systemic insulin resistance, brain insulin signaling normalized. As FOXOs and PGC-1α are essential for memory and long-term neuronal function and regeneration and as Aβ1-40/42 and phospho-tau may increase interneuronal plaques and intraneuronal tangles, presently observed aberrations in hyperinsulinemic states may participate in linking insulin resistance to AD.
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Affiliation(s)
- Mini Sajan
- Medical, Neurology, Psychiatry, and Research Services, James A. Haley Veterans Hospital, Tampa, FL Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL
| | - Barbara Hansen
- Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL
| | - Robert Ivey
- Medical, Neurology, Psychiatry, and Research Services, James A. Haley Veterans Hospital, Tampa, FL
| | - Joshua Sajan
- Medical, Neurology, Psychiatry, and Research Services, James A. Haley Veterans Hospital, Tampa, FL
| | - Csilla Ari
- Department of Molecular Pharmacology and Physiology, Morsani College of Medicine, University of South Florida, Tampa, FL
| | - Shijie Song
- Medical, Neurology, Psychiatry, and Research Services, James A. Haley Veterans Hospital, Tampa, FL
| | | | | | - Margaret Farese-Higgs
- Medical, Neurology, Psychiatry, and Research Services, James A. Haley Veterans Hospital, Tampa, FL
| | - Robert V Farese
- Medical, Neurology, Psychiatry, and Research Services, James A. Haley Veterans Hospital, Tampa, FL Department of Internal Medicine, Morsani College of Medicine, University of South Florida, Tampa, FL
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48
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Chami B, Steel AJ, De La Monte SM, Sutherland GT. The rise and fall of insulin signaling in Alzheimer's disease. Metab Brain Dis 2016; 31:497-515. [PMID: 26883429 DOI: 10.1007/s11011-016-9806-1] [Citation(s) in RCA: 38] [Impact Index Per Article: 4.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 11/04/2015] [Accepted: 02/03/2016] [Indexed: 02/06/2023]
Abstract
The prevalence of both diabetes and Alzheimer's disease (AD) are reaching epidemic proportions worldwide. Alarmingly, diabetes is also a risk factor for Alzheimer's disease. The AD brain is characterised by the accumulation of peptides called Aβ as plaques in the neuropil and hyperphosphorylated tau protein in the form of neurofibrillary tangles within neurons. How diabetes confers risk is unknown but a simple linear relationship has been proposed whereby the hyperinsulinemia associated with type 2 diabetes leads to decreased insulin signaling in the brain, with downregulation of the PI3K/AKT signalling pathway and its inhibition of the major tau kinase, glycogen synthase kinase 3β. The earliest studies of post mortem AD brain tissue largely confirmed this cascade of events but subsequent studies have generally found either an upregulation of AKT activity, or that the relationship between insulin signaling and AD is independent of glycogen synthase kinase 3β altogether. Given the lack of success of beta-amyloid-reducing therapies in clinical trials, there is intense interest in finding alternative or adjunctive therapeutic targets for AD. Insulin signaling is a neuroprotective pathway and represents an attractive therapeutic option. However, this incredibly complex signaling pathway is not fully understood in the human brain and particularly in the context of AD. Here, we review the ups and downs of the research efforts aimed at understanding how diabetes modifies AD risk.
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Affiliation(s)
- B Chami
- Redox Biology, The University of Sydney, Sydney, NSW,, 2006, Australia
| | - A J Steel
- Neuropathology Group, Discipline of Pathology, Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia
| | - S M De La Monte
- Department of Neurology, Rhode Island Hospital and the Alpert Medical School of Brown University, Providence, RI, USA
- Department of Neurosurgery, Rhode Island Hospital and the Alpert Medical School of Brown University, Providence, RI, USA
- Department of Pathology, Rhode Island Hospital and the Alpert Medical School of Brown University, Providence, RI, USA
| | - Greg T Sutherland
- Neuropathology Group, Discipline of Pathology, Sydney Medical School, The University of Sydney, Sydney, NSW, 2006, Australia.
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49
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Knafo S, Sánchez-Puelles C, Palomer E, Delgado I, Draffin JE, Mingo J, Wahle T, Kaleka K, Mou L, Pereda-Perez I, Klosi E, Faber EB, Chapman HM, Lozano-Montes L, Ortega-Molina A, Ordóñez-Gutiérrez L, Wandosell F, Viña J, Dotti CG, Hall RA, Pulido R, Gerges NZ, Chan AM, Spaller MR, Serrano M, Venero C, Esteban JA. PTEN recruitment controls synaptic and cognitive function in Alzheimer's models. Nat Neurosci 2016; 19:443-53. [DOI: 10.1038/nn.4225] [Citation(s) in RCA: 96] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2015] [Accepted: 12/03/2015] [Indexed: 11/09/2022]
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50
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Meeker KD, Meabon JS, Cook DG. Partial Loss of the Glutamate Transporter GLT-1 Alters Brain Akt and Insulin Signaling in a Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2016; 45:509-20. [PMID: 25589729 DOI: 10.3233/jad-142304] [Citation(s) in RCA: 24] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
The glutamate transporter GLT-1 (also called EAAT2 in humans) plays a critical role in regulating extracellular glutamate levels in the central nervous system (CNS). In Alzheimer's disease (AD), EAAT2 loss is associated with neuropathology and cognitive impairment. In keeping with this, we have reported that partial GLT-1 loss (GLT-1+/-) causes early-occurring cognitive deficits in mice harboring familial AD AβPPswe/PS1ΔE9 mutations. GLT-1 plays important roles in several molecular pathways that regulate brain metabolism, including Akt and insulin signaling in astrocytes. Significantly, AD pathogenesis also involves chronic Akt activation and reduced insulin signaling in the CNS. In this report we tested the hypothesis that GLT-1 heterozygosity (which reduces GLT-1 to levels that are comparable to losses in AD patients) in AβPPswe/PS1ΔE9 mice would induce sustained activation of Akt and disturb components of the CNS insulin signaling cascade. We found that partial GLT-1 loss chronically increased Akt activation (reflected by increased phosphorylation at serine 473), impaired insulin signaling (reflected by decreased IRβ phosphorylation of tyrosines 1150/1151 and increased IRS-1 phosphorylation at serines 632/635 - denoted as 636/639 in humans), and reduced insulin degrading enzyme (IDE) activity in brains of mice expressing familial AβPPswe/PS1ΔE9 AD mutations. GLT-1 loss also caused an apparent compensatory increase in IDE activity in the liver, an organ that has been shown to regulate peripheral amyloid-β levels and expresses GLT-1. Taken together, these findings demonstrate that partial GLT-1 loss can cause insulin/Akt signaling abnormalities that are in keeping with those observed in AD.
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Affiliation(s)
- Kole D Meeker
- Department of Pharmacology, University of Washington School of Medicine, Seattle, WA, USA Geriatric Research, Education, and Clinical Center (GRECC), Veterans Affairs Puget Sound Health Care System (VAPSHCS), Seattle, WA, USA
| | - James S Meabon
- Mental Illness Research, Education, and Clinical Center (MIRECC), Veterans Affairs Puget Sound Health Care System (VAPSHCS), Seattle, WA, USA Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA, USA
| | - David G Cook
- Department of Pharmacology, University of Washington School of Medicine, Seattle, WA, USA Geriatric Research, Education, and Clinical Center (GRECC), Veterans Affairs Puget Sound Health Care System (VAPSHCS), Seattle, WA, USA Division of Gerontology, Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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