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Mesa H, Zhang EY, Wang Y, Zhang Q. Human neurons lacking amyloid precursor protein exhibit cholesterol-associated developmental and presynaptic deficits. J Cell Physiol 2024; 239:e30999. [PMID: 36966431 DOI: 10.1002/jcp.30999] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/29/2023] [Accepted: 03/06/2023] [Indexed: 03/27/2023]
Abstract
Amyloid precursor protein (APP) produces aggregable β-amyloid peptides and its mutations are associated with familial Alzheimer's disease (AD), which makes it one of the most studied proteins. However, APP's role in the human brain remains unclear despite years of investigation. One problem is that most studies on APP have been carried out in cell lines or model organisms, which are physiologically different from human neurons in the brain. Recently, human-induced neurons (hiNs) derived from induced pluripotent stem cells (iPSCs) provide a practical platform for studying the human brain in vitro. Here, we generated APP-null iPSCs using CRISPR/Cas9 genome editing technology and differentiate them into matured human neurons with functional synapses using a two-step procedure. During hiN differentiation and maturation, APP-null cells exhibited less neurite growth and reduced synaptogenesis in serum-free but not serum-containing media. We have found that cholesterol (Chol) remedies those developmental defects in APP-null cells, consistent with Chol's role in neurodevelopment and synaptogenesis. The phenotypic rescue was also achieved by coculturing those cells with wild-type mouse astrocytes, suggesting that APP's developmental role is likely astrocytic. Next, we examined matured hiNs using patch-clamp recording and detected reduced synaptic transmission in APP-null cells. This change was largely due to decreased synaptic vesicle (SV) release and retrieval, which was confirmed by live-cell imaging using two SV-specific fluorescent reporters. Adding Chol shortly before stimulation mitigated the SV deficits in APP-null iNs, indicating that APP facilitates presynaptic membrane Chol turnover during the SV exo-/endocytosis cycle. Taken together, our study in hiNs supports the notion that APP contributes to neurodevelopment, synaptogenesis, and neurotransmission via maintaining brain Chol homeostasis. Given the vital role of Chol in the central nervous system, the functional connection between APP and Chol bears important implications in the pathogenesis of AD.
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Affiliation(s)
- Haylee Mesa
- Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida, USA
| | - Elaine Y Zhang
- Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida, USA
- Brentwood High School, Brentwood, Tennessee, USA
| | - Yingcai Wang
- Department of Biomedical Sciences, Florida Atlantic University, Boca Raton, Florida, USA
| | - Qi Zhang
- Stiles-Nicholson Brain Institute, Florida Atlantic University, Jupiter, Florida, USA
- Department of Chemistry and Biochemistry, Florida Atlantic University, Boca Raton, Florida, USA
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2
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Velezmoro Jauregui G, Vukić D, Onyango IG, Arias C, Novotný JS, Texlová K, Wang S, Kovačovicova KL, Polakova N, Zelinkova J, Čarna M, Lacovich V, Head BP, Havas D, Mistrik M, Zorec R, Verkhratsky A, Keegan L, O'Connell MA, Rissman R, Stokin GB. Amyloid precursor protein induces reactive astrogliosis. Acta Physiol (Oxf) 2024; 240:e14142. [PMID: 38584589 DOI: 10.1111/apha.14142] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/25/2024] [Revised: 03/01/2024] [Accepted: 03/05/2024] [Indexed: 04/09/2024]
Abstract
AIM Astrocytes respond to stressors by acquiring a reactive state characterized by changes in their morphology and function. Molecules underlying reactive astrogliosis, however, remain largely unknown. Given that several studies observed increase in the Amyloid Precursor Protein (APP) in reactive astrocytes, we here test whether APP plays a role in reactive astrogliosis. METHODS We investigated whether APP instigates reactive astroglios by examining in vitro and in vivo the morphology and function of naive and APP-deficient astrocytes in response to APP and well-established stressors. RESULTS Overexpression of APP in cultured astrocytes led to remodeling of the intermediate filament network, enhancement of cytokine production, and activation of cellular programs centered around the interferon (IFN) pathway, all signs of reactive astrogliosis. Conversely, APP deletion abrogated remodeling of the intermediate filament network and blunted expression of IFN-stimulated gene products in response to lipopolysaccharide. Following traumatic brain injury (TBI), mouse reactive astrocytes also exhibited an association between APP and IFN, while APP deletion curbed the increase in glial fibrillary acidic protein observed canonically in astrocytes in response to TBI. CONCLUSIONS The APP thus represents a candidate molecular inducer and regulator of reactive astrogliosis. This finding has implications for understanding pathophysiology of neurodegenerative and other diseases of the nervous system characterized by reactive astrogliosis and opens potential new therapeutic avenues targeting APP and its pathways to modulate reactive astrogliosis.
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Affiliation(s)
- Gretsen Velezmoro Jauregui
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St. Anne's University Hospital, Brno, Czech Republic
- Department of Biology, Faculty of Medicine, Masaryk University, Brno, Czech Republic
| | - Dragana Vukić
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
- Faculty of Science, National Centre for Biomedical Research, Masaryk University, Brno, Czech Republic
| | - Isaac G Onyango
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St. Anne's University Hospital, Brno, Czech Republic
| | - Carlos Arias
- Department of Neurosciences, University of California San Diego, La Jolla, California, USA
| | - Jan S Novotný
- Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacky University Olomouc, Olomouc, Czech Republic
| | - Kateřina Texlová
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St. Anne's University Hospital, Brno, Czech Republic
| | - Shanshan Wang
- Veterans Affairs San Diego Healthcare System, San Diego, USA
- Department of Anesthesia, University of California San Diego, La Jolla, California, USA
| | | | - Natalie Polakova
- Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacky University Olomouc, Olomouc, Czech Republic
| | - Jana Zelinkova
- Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacky University Olomouc, Olomouc, Czech Republic
| | - Maria Čarna
- Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacky University Olomouc, Olomouc, Czech Republic
| | - Valentina Lacovich
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Brian P Head
- Veterans Affairs San Diego Healthcare System, San Diego, USA
- Department of Anesthesia, University of California San Diego, La Jolla, California, USA
| | | | - Martin Mistrik
- Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacky University Olomouc, Olomouc, Czech Republic
| | - Robert Zorec
- Laboratory of Neuroendocrinology, Molecular Cell Physiology, Faculty of Medicine, Institute of Pathophysiology, University of Ljubljana, Ljubljana, Slovenia
- Celica Biomedical, Technology Park, Ljubljana, Slovenia
| | - Alexei Verkhratsky
- Faculty of Biology, Medicine and Health, University of Manchester, Manchester, UK
- Achucarro Centre for Neuroscience, IIKERBASQUE, Basque Foundation for Science, Bilbao, Spain
- Department of Stem Cell Biology, State Research Institute Centre for Innovative Medicine, Vilnius, Lithuania
- Department of Forensic Analytical Toxicology, School of Forensic Medicine, China Medical University, Shenyang, Liaoning Province, China
| | - Liam Keegan
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Mary A O'Connell
- Central European Institute of Technology, Masaryk University, Brno, Czech Republic
| | - Robert Rissman
- Department of Neurosciences, University of California San Diego, La Jolla, California, USA
| | - Gorazd B Stokin
- Translational Ageing and Neuroscience Program, Centre for Translational Medicine, International Clinical Research Centre, St. Anne's University Hospital, Brno, Czech Republic
- Faculty of Medicine and Dentistry, Institute of Molecular and Translational Medicine, Palacky University Olomouc, Olomouc, Czech Republic
- Department of Neurology, Gloucestershire Royal Hospital, Gloucestershire NHS Foundation Trust, Gloucester, UK
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3
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Maaliki D, Jaffa AA, Nasser S, Sahebkar A, Eid AH. Adrenoceptor Desensitization: Current Understanding of Mechanisms. Pharmacol Rev 2024; 76:358-387. [PMID: 38697858 DOI: 10.1124/pharmrev.123.000831] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2023] [Revised: 01/15/2024] [Accepted: 01/18/2024] [Indexed: 05/05/2024] Open
Abstract
G-protein coupled receptors (GPCRs) transduce a wide range of extracellular signals. They are key players in the majority of biologic functions including vision, olfaction, chemotaxis, and immunity. However, as essential as most of them are to body function and homeostasis, overactivation of GPCRs has been implicated in many pathologic diseases such as cancer, asthma, and heart failure (HF). Therefore, an important feature of G protein signaling systems is the ability to control GPCR responsiveness, and one key process to control overstimulation involves initiating receptor desensitization. A number of steps are appreciated in the desensitization process, including cell surface receptor phosphorylation, internalization, and downregulation. Rapid or short-term desensitization occurs within minutes and involves receptor phosphorylation via the action of intracellular protein kinases, the binding of β-arrestins, and the consequent uncoupling of GPCRs from their cognate heterotrimeric G proteins. On the other hand, long-term desensitization occurs over hours to days and involves receptor downregulation or a decrease in cell surface receptor protein level. Of the proteins involved in this biologic phenomenon, β-arrestins play a particularly significant role in both short- and long-term desensitization mechanisms. In addition, β-arrestins are involved in the phenomenon of biased agonism, where the biased ligand preferentially activates one of several downstream signaling pathways, leading to altered cellular responses. In this context, this review discusses the different patterns of desensitization of the α 1-, α 2- and the β adrenoceptors and highlights the role of β-arrestins in regulating physiologic responsiveness through desensitization and biased agonism. SIGNIFICANCE STATEMENT: A sophisticated network of proteins orchestrates the molecular regulation of GPCR activity. Adrenoceptors are GPCRs that play vast roles in many physiological processes. Without tightly controlled desensitization of these receptors, homeostatic imbalance may ensue, thus precipitating various diseases. Here, we critically appraise the mechanisms implicated in adrenoceptor desensitization. A better understanding of these mechanisms helps identify new druggable targets within the GPCR desensitization machinery and opens exciting therapeutic fronts in the treatment of several pathologies.
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Affiliation(s)
- Dina Maaliki
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
| | - Aneese A Jaffa
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
| | - Suzanne Nasser
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
| | - Amirhossein Sahebkar
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
| | - Ali H Eid
- Department of Pharmacology and Toxicology, American University of Beirut, Beirut, Lebanon (D.M.); School of Medicine, University of South Carolina, Columbia, South Carolina (A.A.J.); Keele University, Staffordshire, United Kingdom (S.N.); Applied Biomedical Research Center, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); Biotechnology Research Center, Pharmaceutical Technology Institute, Mashhad University of Medical Sciences, Mashhad, Iran (A.S.); and Department of Basic Medical Sciences, College of Medicine, QU Health, Qatar University, Doha, Qatar (A.H.E.)
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4
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Singh CSB, Johns KM, Kari S, Munro L, Mathews A, Fenninger F, Pfeifer CG, Jefferies WA. Conclusive demonstration of iatrogenic Alzheimer's disease transmission in a model of stem cell transplantation. Stem Cell Reports 2024; 19:456-468. [PMID: 38552634 PMCID: PMC11096610 DOI: 10.1016/j.stemcr.2024.02.012] [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: 07/23/2020] [Revised: 02/27/2024] [Accepted: 02/28/2024] [Indexed: 04/12/2024] Open
Abstract
The risk of iatrogenic disease is often underestimated as a concern in contemporary medical procedures, encompassing tissue and organ transplantation, stem cell therapies, blood transfusions, and the administration of blood-derived products. In this context, despite the prevailing belief that Alzheimer's disease (AD) manifests primarily in familial and sporadic forms, our investigation reveals an unexpected transplantable variant of AD in a preclinical context, potentially indicating iatrogenic transmission in AD patients. Through adoptive transplantation of donor bone marrow stem cells carrying a mutant human amyloid precursor protein (APP) transgene into either APP-deficient knockout or normal recipient animals, we observed rapid development of AD pathological hallmarks. These pathological features were significantly accelerated and emerged within 6-9 months post transplantation and included compromised blood-brain barrier integrity, heightened cerebral vascular neoangiogenesis, elevated brain-associated β-amyloid levels, and cognitive impairment. Furthermore, our findings underscore the contribution of β-amyloid burden originating outside of the central nervous system to AD pathogenesis within the brain. We conclude that stem cell transplantation from donors harboring a pathogenic mutant allele can effectively transfer central nervous system diseases to healthy recipients, mirroring the pathogenesis observed in the donor. Consequently, our observations advocate for genomic sequencing of donor specimens prior to tissue, organ, or stem cell transplantation therapies, as well as blood transfusions and blood-derived product administration, to mitigate the risk of iatrogenic diseases.
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Affiliation(s)
- Chaahat S B Singh
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada; Department of Medical Genetics, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada
| | - Kelly Marie Johns
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada; Department of Medical Genetics, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada
| | - Suresh Kari
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada; Department of Medical Genetics, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada
| | - Lonna Munro
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada
| | - Angela Mathews
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada; Department of Medical Genetics, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada
| | - Franz Fenninger
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada
| | - Cheryl G Pfeifer
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada
| | - Wilfred A Jefferies
- Michael Smith Laboratories, University of British Columbia, 2185 East Mall, Vancouver, BC V6T 1Z4, Canada; The Vancouver Prostate Centre, Vancouver General Hospital, 2660 Oak Street, Vancouver, BC V6H 3Z6, Canada; Centre for Blood Research, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; The Djavad Mowafaghian Centre for Brain Health, University of British Columbia, 2215 Wesbrook Mall, Vancouver, BC V6T 1Z4, Canada; Department of Medical Genetics, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; Department of Microbiology and Immunology, University of British Columbia, 2350 Health Sciences Mall, Vancouver, BC V6T 1Z4, Canada; Department of Zoology, University of British Columbia, 6270 University Boulevard, Vancouver, BC V6T 1Z4, Canada; Department of Urologic Sciences, University of British Columbia, Level 6, 2775 Laurel Street, Vancouver, BC V5Z 1M9 Canada.
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5
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Galasko D, Farlow MR, Lucey BP, Honig LS, Elbert D, Bateman R, Momper J, Thomas R, Rissman RA, Pa J, Aslanyan V, Balasubramanian A, West T, Maccecchini M, Feldman HH. A multicenter, randomized, double-blind, placebo-controlled ascending dose study to evaluate the safety, tolerability, pharmacokinetics (PK) and pharmacodynamic (PD) effects of Posiphen in subjects with Early Alzheimer's Disease. MEDRXIV : THE PREPRINT SERVER FOR HEALTH SCIENCES 2024:2024.03.20.24304638. [PMID: 38562783 PMCID: PMC10984053 DOI: 10.1101/2024.03.20.24304638] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 04/04/2024]
Abstract
Background Amyloid beta protein (Aβ) is a treatment target in Alzheimer's Disease (AD). Lowering production of its parent protein, APP, has benefits in preclinical models. Posiphen binds to an iron-responsive element in APP mRNA and decreases translation of APP and Aβ. To augment human data for Posiphen, we evaluated safety, tolerability and pharmacokinetic and pharmacodynamic (PD) effects on Aβ metabolism using Stable Isotope Labeling Kinetic (SILK) analysis. Methods Double-blind phase 1b randomized ascending dose clinical trial, at five sites, under an IRB-approved protocol. Participants with mild cognitive impairment or mild AD (Early AD) with positive CSF biomarkers were randomized (within each dose arm) to Posiphen or placebo. Pretreatment assessment included lumbar puncture for CSF. Participants took Posiphen or placebo for 21-23 days, then underwent CSF catheter placement, intravenous infusion of 13C6-leucine, and CSF sampling for 36 hours. Safety and tolerability were assessed through participant reports, EKG and laboratory tests. CSF SILK analysis measured Aβ40, 38 and 42 with immunoprecipitation-mass spectrometry. Baseline and day 21 CSF APP, Aβ and other biomarkers were measured with immunoassays. The Mini-Mental State Exam and ADAS-cog12 were given at baseline and day 21. Results From June 2017 to December 2021, 19 participants were enrolled, in dose cohorts (6 active: 2 placebo) of 60 mg once/day and 60 mg twice/day; 1 participant was enrolled and completed 60 mg three times/day. 10 active drug and 5 placebo participants completed all study procedures. Posiphen was safe and well-tolerated. 8 participants had headaches related to CSF catheterization; 5 needed blood patches. Prespecified SILK analyses of Fractional Synthesis Rate (FSR) for CSF Aβ40 showed no significant overall or dose-dependent effects of Posiphen vs. placebo. Comprehensive multiparameter modeling of APP kinetics supported dose-dependent lowering of APP production by Posiphen. Cognitive measures and CSF biomarkers did not change significantly from baseline to 21 days in Posiphen vs placebo groups. Conclusions Posiphen was safe and well-tolerated in Early AD. A multicenter SILK study was feasible. Findings are limited by small sample size but provide additional supportive safety and PK data. Comprehensive modeling of biomarker dynamics using SILK data may reveal subtle drug effects. Trial registration NCT02925650 on clinicaltrials.gov.
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Özcan GG, Lim S, Canning T, Tirathdas L, Donnelly J, Kundu T, Rihel J. Genetic and chemical disruption of amyloid precursor protein processing impairs zebrafish sleep maintenance. iScience 2024; 27:108870. [PMID: 38318375 PMCID: PMC10839650 DOI: 10.1016/j.isci.2024.108870] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/20/2022] [Revised: 10/12/2023] [Accepted: 01/08/2024] [Indexed: 02/07/2024] Open
Abstract
Amyloid precursor protein (APP) is a brain-rich, single pass transmembrane protein that is proteolytically processed into multiple products, including amyloid-beta (Aβ), a major driver of Alzheimer disease (AD). Although both overexpression of APP and exogenously delivered Aβ lead to changes in sleep, whether APP processing plays an endogenous role in regulating sleep is unknown. Here, we demonstrate that APP processing into Aβ40 and Aβ42 is conserved in zebrafish and then describe sleep/wake phenotypes in loss-of-function appa and appb mutants. Larvae with mutations in appa had reduced waking activity, whereas larvae that lacked appb had shortened sleep bout durations at night. Treatment with the γ-secretase inhibitor DAPT also shortened night sleep bouts, whereas the BACE-1 inhibitor lanabecestat lengthened sleep bouts. Intraventricular injection of P3 also shortened night sleep bouts, suggesting that the proper balance of Appb proteolytic processing is required for normal sleep maintenance in zebrafish.
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Affiliation(s)
- Güliz Gürel Özcan
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Sumi Lim
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Thomas Canning
- Department of Biostatistics and Health Informatics, Institute of Psychiatry, Psychology and Neuroscience, King’s College London, London, UK
- Social, Genetic & Developmental Psychiatry Centre, Institute of Psychiatry, Psychology & Neuroscience, King’s College London, London, UK
| | - Lavitasha Tirathdas
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Joshua Donnelly
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Tanushree Kundu
- Department of Cell and Developmental Biology, University College London, London, UK
| | - Jason Rihel
- Department of Cell and Developmental Biology, University College London, London, UK
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Lai TT, Tsai YH, Liou CW, Fan CH, Hou YT, Yao TH, Chuang HL, Wu WL. The gut microbiota modulate locomotion via vagus-dependent glucagon-like peptide-1 signaling. NPJ Biofilms Microbiomes 2024; 10:2. [PMID: 38228675 DOI: 10.1038/s41522-024-00477-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2023] [Accepted: 01/04/2024] [Indexed: 01/18/2024] Open
Abstract
Locomotor activity is an innate behavior that can be triggered by gut-motivated conditions, such as appetite and metabolic condition. Various nutrient-sensing receptors distributed in the vagal terminal in the gut are crucial for signal transduction from the gut to the brain. The levels of gut hormones are closely associated with the colonization status of the gut microbiota, suggesting a complicated interaction among gut bacteria, gut hormones, and the brain. However, the detailed mechanism underlying gut microbiota-mediated endocrine signaling in the modulation of locomotion is still unclear. Herein, we show that broad-spectrum antibiotic cocktail (ABX)-treated mice displayed hypolocomotion and elevated levels of the gut hormone glucagon-like peptide-1 (GLP-1). Blockade of the GLP-1 receptor and subdiaphragmatic vagal transmission rescued the deficient locomotor phenotype in ABX-treated mice. Activation of the GLP-1 receptor and vagal projecting brain regions led to hypolocomotion. Finally, selective antibiotic treatment dramatically increased serum GLP-1 levels and decreased locomotion. Colonizing Lactobacillus reuteri and Bacteroides thetaiotaomicron in microbiota-deficient mice suppressed GLP-1 levels and restored the hypolocomotor phenotype. Our findings identify a mechanism by which specific gut microbes mediate host motor behavior via the enteroendocrine and vagal-dependent neural pathways.
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Affiliation(s)
- Tzu-Ting Lai
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Yu-Hsuan Tsai
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Chia-Wei Liou
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Ching-Hsiang Fan
- Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Yu-Tian Hou
- Department of Biomedical Engineering, College of Engineering, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Tzu-Hsuan Yao
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan
| | - Hsiao-Li Chuang
- National Laboratory Animal Center, National Applied Research Laboratories, Taipei, 115202, Taiwan
| | - Wei-Li Wu
- Institute of Basic Medical Sciences, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan.
- Department of Physiology, College of Medicine, National Cheng Kung University, 1 University Rd., Tainan, 70101, Taiwan.
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Dunot J, Ribera A, Pousinha PA, Marie H. Spatiotemporal insights of APP function. Curr Opin Neurobiol 2023; 82:102754. [PMID: 37542943 DOI: 10.1016/j.conb.2023.102754] [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: 04/17/2023] [Revised: 06/29/2023] [Accepted: 07/07/2023] [Indexed: 08/07/2023]
Abstract
The amyloid-β precursor protein (APP) is a ubiquitous protein with a strong genetic link to Alzheimer's disease. Although the protein was identified more than forty years ago, its physiological function is still unclear. In recent years, advances in technology have allowed researchers to tackle APP functions in greater depth. In this review, we discuss the latest research pertaining to APP functions from development to aging. We also address the different roles that APP could play in specific types of cells of the central and peripheral nervous system and in other organs of the body. We argue that, until we fully identify the functions of APP in space and time, we will be missing important pieces of the puzzle to solve its pathological implication in Alzheimer's disease and beyond.
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Affiliation(s)
- Jade Dunot
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275, 06560, Valbonne, France. https://twitter.com/DunotJade
| | - Aurore Ribera
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275, 06560, Valbonne, France. https://twitter.com/aurore_et_al_
| | - Paula A Pousinha
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275, 06560, Valbonne, France.
| | - Hélène Marie
- Université Côte d'Azur, CNRS, Institut de Pharmacologie Moléculaire et Cellulaire, UMR7275, 06560, Valbonne, France.
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9
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Jung BK, Ryu KY. Lipocalin-2: a therapeutic target to overcome neurodegenerative diseases by regulating reactive astrogliosis. Exp Mol Med 2023; 55:2138-2146. [PMID: 37779143 PMCID: PMC10618504 DOI: 10.1038/s12276-023-01098-7] [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: 06/21/2023] [Revised: 07/14/2023] [Accepted: 07/17/2023] [Indexed: 10/03/2023] Open
Abstract
Glial cell activation precedes neuronal cell death during brain aging and the progression of neurodegenerative diseases. Under neuroinflammatory stress conditions, lipocalin-2 (LCN2), also known as neutrophil gelatinase-associated lipocalin or 24p3, is produced and secreted by activated microglia and reactive astrocytes. Lcn2 expression levels are known to be increased in various cells, including reactive astrocytes, through the activation of the NF-κB signaling pathway. In the central nervous system, as LCN2 exerts neurotoxicity when secreted from reactive astrocytes, many researchers have attempted to identify various strategies to inhibit LCN2 production, secretion, and function to minimize neuroinflammation and neuronal cell death. These strategies include regulation at the transcriptional, posttranscriptional, and posttranslational levels, as well as blocking its functions using neutralizing antibodies or antagonists of its receptor. The suppression of NF-κB signaling is a strategy to inhibit LCN2 production, but it may also affect other cellular activities, raising questions about its effectiveness and feasibility. Recently, LCN2 was found to be a target of the autophagy‒lysosome pathway. Therefore, autophagy activation may be a promising therapeutic strategy to reduce the levels of secreted LCN2 and overcome neurodegenerative diseases. In this review, we focused on research progress on astrocyte-derived LCN2 in the central nervous system.
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Affiliation(s)
- Byung-Kwon Jung
- Department of Life Science, University of Seoul, Seoul, 02504, Republic of Korea
| | - Kwon-Yul Ryu
- Department of Life Science, University of Seoul, Seoul, 02504, Republic of Korea.
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10
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Chau DDL, Ng LLH, Zhai Y, Lau KF. Amyloid precursor protein and its interacting proteins in neurodevelopment. Biochem Soc Trans 2023; 51:1647-1659. [PMID: 37387352 PMCID: PMC10629809 DOI: 10.1042/bst20221527] [Citation(s) in RCA: 6] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/24/2023] [Revised: 06/22/2023] [Accepted: 06/26/2023] [Indexed: 07/01/2023]
Abstract
Amyloid precursor protein (APP) is a key molecule in the pathogenesis of Alzheimer's disease (AD) as the pathogenic amyloid-β peptide is derived from it. Two closely related APP family proteins (APPs) have also been identified in mammals. Current knowledge, including genetic analyses of gain- and loss-of-function mutants, highlights the importance of APPs in various physiological functions. Notably, APPs consist of multiple extracellular and intracellular protein-binding regions/domains. Protein-protein interactions are crucial for many cellular processes. In past decades, many APPs interactors have been identified which assist the revelation of the putative roles of APPs. Importantly, some of these interactors have been shown to influence several APPs-mediated neuronal processes which are found defective in AD and other neurodegenerative disorders. Studying APPs-interactor complexes would not only advance our understanding of the physiological roles of APPs but also provide further insights into the association of these processes to neurodegeneration, which may lead to the development of novel therapies. In this mini-review, we summarize the roles of APPs-interactor complexes in neurodevelopmental processes including neurogenesis, neurite outgrowth, axonal guidance and synaptogenesis.
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Affiliation(s)
- Dennis Dik-Long Chau
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Laura Lok-Haang Ng
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Yuqi Zhai
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, China
| | - Kwok-Fai Lau
- School of Life Sciences, Faculty of Science, The Chinese University of Hong Kong, Hong Kong SAR, China
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11
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Nikom D, Zheng S. Alternative splicing in neurodegenerative disease and the promise of RNA therapies. Nat Rev Neurosci 2023; 24:457-473. [PMID: 37336982 DOI: 10.1038/s41583-023-00717-6] [Citation(s) in RCA: 19] [Impact Index Per Article: 19.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/02/2023] [Indexed: 06/21/2023]
Abstract
Alternative splicing generates a myriad of RNA products and protein isoforms of different functions from a single gene. Dysregulated alternative splicing has emerged as a new mechanism broadly implicated in the pathogenesis of neurodegenerative diseases such as Alzheimer disease, amyotrophic lateral sclerosis, frontotemporal dementia, Parkinson disease and repeat expansion diseases. Understanding the mechanisms and functional outcomes of abnormal splicing in neurological disorders is vital in developing effective therapies to treat mis-splicing pathology. In this Review, we discuss emerging research and evidence of the roles of alternative splicing defects in major neurodegenerative diseases and summarize the latest advances in RNA-based therapeutic strategies to target these disorders.
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Affiliation(s)
- David Nikom
- Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, USA
- Center for RNA Biology and Medicine, University of California, Riverside, Riverside, CA, USA
| | - Sika Zheng
- Neuroscience Graduate Program, University of California, Riverside, Riverside, CA, USA.
- Center for RNA Biology and Medicine, University of California, Riverside, Riverside, CA, USA.
- Division of Biomedical Sciences, University of California, Riverside, Riverside, CA, USA.
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12
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Cai W, Li L, Sang S, Pan X, Zhong C. Physiological Roles of β-amyloid in Regulating Synaptic Function: Implications for AD Pathophysiology. Neurosci Bull 2023; 39:1289-1308. [PMID: 36443453 PMCID: PMC10387033 DOI: 10.1007/s12264-022-00985-9] [Citation(s) in RCA: 16] [Impact Index Per Article: 16.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/25/2022] [Accepted: 09/02/2022] [Indexed: 11/29/2022] Open
Abstract
The physiological functions of endogenous amyloid-β (Aβ), which plays important role in the pathology of Alzheimer's disease (AD), have not been paid enough attention. Here, we review the multiple physiological effects of Aβ, particularly in regulating synaptic transmission, and the possible mechanisms, in order to decipher the real characters of Aβ under both physiological and pathological conditions. Some worthy studies have shown that the deprivation of endogenous Aβ gives rise to synaptic dysfunction and cognitive deficiency, while the moderate elevation of this peptide enhances long term potentiation and leads to neuronal hyperexcitability. In this review, we provide a new view for understanding the role of Aβ in AD pathophysiology from the perspective of physiological meaning.
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Affiliation(s)
- Wenwen Cai
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Linxi Li
- Basic Medical College, Nanchang University, Nanchang, 330031, China
| | - Shaoming Sang
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China
| | - Xiaoli Pan
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
| | - Chunjiu Zhong
- Department of Neurology, Zhongshan Hospital, Fudan University, Shanghai, 200032, China.
- State Key Laboratory of Medical Neurobiology, Institutes of Brain Science & Collaborative Innovation Center for Brain Science, Fudan University, Shanghai, 200032, China.
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13
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Zhang Y, Chen H, Li R, Sterling K, Song W. Amyloid β-based therapy for Alzheimer's disease: challenges, successes and future. Signal Transduct Target Ther 2023; 8:248. [PMID: 37386015 PMCID: PMC10310781 DOI: 10.1038/s41392-023-01484-7] [Citation(s) in RCA: 58] [Impact Index Per Article: 58.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2023] [Revised: 05/05/2023] [Accepted: 05/09/2023] [Indexed: 07/01/2023] Open
Abstract
Amyloid β protein (Aβ) is the main component of neuritic plaques in Alzheimer's disease (AD), and its accumulation has been considered as the molecular driver of Alzheimer's pathogenesis and progression. Aβ has been the prime target for the development of AD therapy. However, the repeated failures of Aβ-targeted clinical trials have cast considerable doubt on the amyloid cascade hypothesis and whether the development of Alzheimer's drug has followed the correct course. However, the recent successes of Aβ targeted trials have assuaged those doubts. In this review, we discussed the evolution of the amyloid cascade hypothesis over the last 30 years and summarized its application in Alzheimer's diagnosis and modification. In particular, we extensively discussed the pitfalls, promises and important unanswered questions regarding the current anti-Aβ therapy, as well as strategies for further study and development of more feasible Aβ-targeted approaches in the optimization of AD prevention and treatment.
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Affiliation(s)
- Yun Zhang
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital, Capital Medical University, Beijing, China.
| | - Huaqiu Chen
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital, Capital Medical University, Beijing, China
| | - Ran Li
- The Second Affiliated Hospital and Yuying Children's Hospital, Institute of Aging, Key Laboratory of Alzheimer's Disease of Zhejiang Province, Wenzhou Medical University, Wenzhou, Zhejiang, China
| | - Keenan Sterling
- Townsend Family Laboratories, Department of Psychiatry, The University of British Columbia, Vancouver, BC, V6T 1Z3, Canada
| | - Weihong Song
- National Clinical Research Center for Geriatric Disorders, Xuanwu Hospital, Capital Medical University, Beijing, China.
- The Second Affiliated Hospital and Yuying Children's Hospital, Institute of Aging, Key Laboratory of Alzheimer's Disease of Zhejiang Province, Wenzhou Medical University, Wenzhou, Zhejiang, China.
- Townsend Family Laboratories, Department of Psychiatry, The University of British Columbia, Vancouver, BC, V6T 1Z3, Canada.
- Oujiang Laboratory (Zhejiang Lab for Regenerative Medicine, Vision and Brain Health), Wenzhou, Zhejiang, China.
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14
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Wang Y, Miao Z, Xu C, Cai Y, Yang Y, Hu Y, Zhao M, Shao Y, Li Z, Chen J, Chen S, Wang L. Pathological convergence of APP and SNCA deficiency in hippocampal degeneration of young rats. Cell Death Dis 2023; 14:325. [PMID: 37179386 PMCID: PMC10183039 DOI: 10.1038/s41419-023-05846-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/18/2022] [Accepted: 05/02/2023] [Indexed: 05/15/2023]
Abstract
The common pathogenesis of Alzheimer's disease (AD) and Parkinson's disease (PD) has been supported by biochemical, genetic and molecular evidence. Mitochondrial dysfunction is considered to be the common pathology in early AD and PD. The physiological regulation of APP and α-synuclein on mitochondria remains unclear, let alone whether they share common regulatory mechanisms affecting the development of neurodegenerative diseases. By studying gene knockout rats, the commonality of physiological APP and α-synuclein in maintaining mitochondrial function through calcium homeostasis regulation was revealed, which was critical in inhibiting hippocampal degeneration in young rats. APP and α-synuclein both control hippocampal mitochondrial calcium intake and outflow. In the mitochondrial calcium influx regulation, APP and α-synuclein are located on the mitochondrial-associated endoplasmic reticulum membrane (MAM) and converge to regulate the IP3R1-Grp75-VDAC2 axis. Mitochondrial calcium outflow is redundantly promoted by both α-synuclein and APP. Loss of APP or SNCA leads to mitochondrial calcium overload, thus enhancing aerobic respiration and ER stress, and ultimately causing excessive apoptosis in the hippocampus and spatial memory impairment in young rats. Based on this study, we believe that the physiological function impairment of APP and SNCA is the early core pathology to induce mitochondrial dysfunction at the early stage of AD and PD, while the IP3R1-Grp75-VDAC2 axis might be the common drug target of these two diseases.
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Affiliation(s)
- Yajie Wang
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Zhikang Miao
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Chang Xu
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
- The Research and Application Center of Precision Medicine, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450014, China
| | - Ying Cai
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yuting Yang
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yue Hu
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Mengna Zhao
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Yue Shao
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Zhiqiang Li
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Jincao Chen
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China
| | - Shi Chen
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China.
- Department of Burn and Plastic Surgery, Shenzhen Institute of Translational Medicine, Health Science Center, the First Affiliated Hospital of Shenzhen University, Shenzhen Second People's Hospital, Shenzhen, 518035, China.
| | - Lianrong Wang
- Brain Center, Department of Neurosurgery, Ministry of Education Key Laboratory of Combinatorial Biosynthesis and Drug Discovery, Zhongnan Hospital of Wuhan University, School of Pharmaceutical Sciences, Wuhan University, Wuhan, 430071, China.
- The Research and Application Center of Precision Medicine, The Second Affiliated Hospital of Zhengzhou University, Zhengzhou University, Zhengzhou, 450014, China.
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15
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Yanagida K, Maruyama R, Tagami S, Kudo T, Okochi M, Fukumori A. APLP2 is predominantly cleaved by β-secretase and γ-secretase in the human brain. Psychogeriatrics 2023; 23:311-318. [PMID: 36691315 DOI: 10.1111/psyg.12933] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/11/2022] [Revised: 12/25/2022] [Accepted: 01/03/2023] [Indexed: 01/25/2023]
Abstract
BACKGROUND Amyloid-β peptide is well-known as a pathogen of Alzheimer's disease, but its precursor, amyloid-beta precursor protein (APP), remains unexplained 30 years after its discovery. APP has two homologues called amyloid precursor-like protein 1 (APLP1) and amyloid precursor-like protein 2 (APLP2), and shares a similar structural organisation with them and has partially overlapping functions. APP family proteins are essential for survival, shown by the crossbreeding analysis of knockout mice of APP family molecules, including APLP1 and APLP2. APLP2 is known to play the most important role among them, but the molecular metabolism of APLP2 is only partially understood. Here, we analysed ectodomain shedding and γ-secretase cleavage of APLP2 by molecular biological and biochemical techniques. METHOD We analysed the culture supernatant of HEK293 cells overexpressing APLP2 and human cerebrospinal fluid. For the analysis of secreted APLP2 fragments, we raised the OA603 antibody that reacts with the juxtamembrane domain of APLP2. Substrate cleavage sites were identified by matrix assisted laser desorption/ionisation mass spectrometry. RESULTS By overexpressing in HEK293 cells, APLP2 undergoes ectodomain shedding at three sites in the extracellular region by α- and β-secretase-like activity and then is intramembranously cleaved at three sites by γ-secretase. In particular, in shedding, α-secretase-like activity was dominant in HEK cells. Surprisingly, in human cerebrospinal fluid, APLP2-derived metabolic fragments were mainly cleaved by β-secretase-like activity, not by α-secretase-like activity. Because APP is also mainly cleaved by beta-site amyloid precursor protein cleaving enzyme 1 in neurons and APLP1 is expressed exclusively in neurons, these findings suggest that APP family proteins may play a common role via β-secretase-like cleavage in the central nerve system. CONCLUSIONS Thus, these findings may contribute to a better understanding of the role of APP family proteins in Alzheimer's disease.
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Affiliation(s)
- Kanta Yanagida
- Department of Mental Health Promotion, Osaka University Graduate School of Medicine, Toyonaka, Japan.,Department of Pharmacotherapeutics II, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki, Japan.,Neuropsychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Riki Maruyama
- Department of Mental Health Promotion, Osaka University Graduate School of Medicine, Toyonaka, Japan.,Department of Pharmacotherapeutics II, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki, Japan
| | - Shinji Tagami
- Neuropsychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Takashi Kudo
- Department of Mental Health Promotion, Osaka University Graduate School of Medicine, Toyonaka, Japan
| | - Masayasu Okochi
- Neuropsychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Akio Fukumori
- Department of Mental Health Promotion, Osaka University Graduate School of Medicine, Toyonaka, Japan.,Department of Pharmacotherapeutics II, Faculty of Pharmacy, Osaka Medical and Pharmaceutical University, Takatsuki, Japan.,Neuropsychiatry, Department of Integrated Medicine, Division of Internal Medicine, Osaka University Graduate School of Medicine, Suita, Japan.,Department of Aging Neurobiology, National Center for Geriatrics and Gerontology, Obu, Japan
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16
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Ma X, Wang D, Liu Y, Liu B, Feng X, Yang W. Transcriptomics and experimental validation-based approach to understand the effect and mechanism of Huangqin tang interfeience with colitis associated colorectal cancer. Heliyon 2023; 9:e13739. [PMID: 36925536 PMCID: PMC10011003 DOI: 10.1016/j.heliyon.2023.e13739] [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: 11/21/2022] [Revised: 02/04/2023] [Accepted: 02/10/2023] [Indexed: 02/27/2023] Open
Abstract
Context Chronic inflammation is usually caused by persistent irritation or uncontrolled infection and is characterized by ongoing tissue damage, injury-induced cellular proliferation and tissue repair. Colitis-associated colorectal cancer (CAC) isone of the classic examples of tumors that are tightly related to chronic inflammation. Background To investigated the key pharmacodynamic genes of HQT interventions in CAC by using transcriptome predictions and experiments.Materials & Methods: We used the azoxymethane/dextran sodium sulfate method to induce the mice CAC model. After preventive administration of HQT to the mice model, colonic tissues were taken for transcriptome sequencing and the transcriptome results were then experimentally validated using quantitative Real-Time PCR technique. Results Transcriptome sequencing revealed that the effect of the mechanism of HQT on the CAC mice model maybe related to its inhibition of accelerated epithelial mesenchymal transition and induction of pyroptosis. The levels of Matrix-metalloproteinases such as MMP-2, MMP-9 were significantly reduced in CAC mice treated with HQT; The mRNA expression for Krt17, App, CD44 and WNT pathway related sites such as Lrrc15, Cldn-1, Mpc1, Agr2 which are related factors affecting the epithelial mesenchymal transition were significantly reduced in CAC mice treated with HQT; the aberrant mRNA expression of inflammasome components that drive pyroptosis, including Nlrp3, Caspase-1, ASC, GSDMD and its mediated product IL-18 have been improved. Conclusions Our findings provide preliminary clarification that inhibiting the progression of CAC by using HQT is effective, the mechanism of action may be relatedto the inhibition of epithelial mesenchymal transition and induction of pyroptosis during tumorigenesis.
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Affiliation(s)
- Xuran Ma
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China.,Institute of Pharmaceutical Research, Shandong University of Traditional Chinese Medicine. Jinan, China
| | - Dunfang Wang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Yaqing Liu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Bin Liu
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Xue Feng
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
| | - Weipeng Yang
- Institute of Chinese Materia Medica, China Academy of Chinese Medical Sciences, Beijing, China
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17
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Wilkins HM. Interactions between amyloid, amyloid precursor protein, and mitochondria. Biochem Soc Trans 2023; 51:173-182. [PMID: 36688439 PMCID: PMC9987971 DOI: 10.1042/bst20220518] [Citation(s) in RCA: 8] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/28/2022] [Revised: 01/10/2023] [Accepted: 01/12/2023] [Indexed: 01/24/2023]
Abstract
Mitochondrial dysfunction and Aβ accumulation are hallmarks of Alzheimer's disease (AD). Decades of research describe a relationship between mitochondrial function and Aβ production. Amyloid precursor protein (APP), of which Aβ is generated from, is found within mitochondria. Studies suggest Aβ can be generated in mitochondria and imported into mitochondria. APP and Aβ alter mitochondrial function, while mitochondrial function alters Aβ production from APP. The role these interactions contribute to AD pathology and progression are unknown. Here, we discuss prior research, the rigor of those studies, and the critical knowledge gaps of relationships between APP, Aβ, and mitochondria.
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Affiliation(s)
- Heather M. Wilkins
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, U.S.A
- Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, U.S.A
- Department of Neurology, University of Kansas Medical Center, Kansas City, KS, U.S.A
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18
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Yoon JH, Hwang J, Son SU, Choi J, You SW, Park H, Cha SY, Maeng S. How Can Insulin Resistance Cause Alzheimer's Disease? Int J Mol Sci 2023; 24:ijms24043506. [PMID: 36834911 PMCID: PMC9966425 DOI: 10.3390/ijms24043506] [Citation(s) in RCA: 7] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/05/2022] [Revised: 01/17/2023] [Accepted: 01/27/2023] [Indexed: 02/12/2023] Open
Abstract
Alzheimer's disease (AD) is a neurodegenerative disorder associated with cognitive decline. Despite worldwide efforts to find a cure, no proper treatment has been developed yet, and the only effective countermeasure is to prevent the disease progression by early diagnosis. The reason why new drug candidates fail to show therapeutic effects in clinical studies may be due to misunderstanding the cause of AD. Regarding the cause of AD, the most widely known is the amyloid cascade hypothesis, in which the deposition of amyloid beta and hyperphosphorylated tau is the cause. However, many new hypotheses were suggested. Among them, based on preclinical and clinical evidence supporting a connection between AD and diabetes, insulin resistance has been pointed out as an important factor in the development of AD. Therefore, by reviewing the pathophysiological background of brain metabolic insufficiency and insulin insufficiency leading to AD pathology, we will discuss how can insulin resistance cause AD.
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Affiliation(s)
- Ji Hye Yoon
- Age-Tech Service Convergence Major, Graduate School of East–West Medical Science, Kyung Hee University, Yongin-si 17104, Republic of Korea
| | - JooHyun Hwang
- Age-Tech Service Convergence Major, Graduate School of East–West Medical Science, Kyung Hee University, Yongin-si 17104, Republic of Korea
| | - Sung Un Son
- Department of Comprehensive Health Science, Graduate School of East–West Medical Science, Kyung Hee University, Yongin-si 17104, Republic of Korea
| | - Junhyuk Choi
- Age-Tech Service Convergence Major, Graduate School of East–West Medical Science, Kyung Hee University, Yongin-si 17104, Republic of Korea
| | - Seung-Won You
- Department of Comprehensive Health Science, Graduate School of East–West Medical Science, Kyung Hee University, Yongin-si 17104, Republic of Korea
| | - Hyunwoo Park
- Department of Comprehensive Health Science, Graduate School of East–West Medical Science, Kyung Hee University, Yongin-si 17104, Republic of Korea
- Health Park Co., Ltd., Seoul 02447, Republic of Korea
| | - Seung-Yun Cha
- Department of Comprehensive Health Science, Graduate School of East–West Medical Science, Kyung Hee University, Yongin-si 17104, Republic of Korea
- Correspondence: (S.-Y.C.); (S.M.); Tel.: +82-31-201-2916 (S.M.)
| | - Sungho Maeng
- Age-Tech Service Convergence Major, Graduate School of East–West Medical Science, Kyung Hee University, Yongin-si 17104, Republic of Korea
- Department of Comprehensive Health Science, Graduate School of East–West Medical Science, Kyung Hee University, Yongin-si 17104, Republic of Korea
- Correspondence: (S.-Y.C.); (S.M.); Tel.: +82-31-201-2916 (S.M.)
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19
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Makdissi S, Parsons BD, Di Cara F. Towards early detection of neurodegenerative diseases: A gut feeling. Front Cell Dev Biol 2023; 11:1087091. [PMID: 36824371 PMCID: PMC9941184 DOI: 10.3389/fcell.2023.1087091] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/01/2022] [Accepted: 01/20/2023] [Indexed: 02/10/2023] Open
Abstract
The gastrointestinal tract communicates with the nervous system through a bidirectional network of signaling pathways called the gut-brain axis, which consists of multiple connections, including the enteric nervous system, the vagus nerve, the immune system, endocrine signals, the microbiota, and its metabolites. Alteration of communications in the gut-brain axis is emerging as an overlooked cause of neuroinflammation. Neuroinflammation is a common feature of the pathogenic mechanisms involved in various neurodegenerative diseases (NDs) that are incurable and debilitating conditions resulting in progressive degeneration and death of neurons, such as in Alzheimer and Parkinson diseases. NDs are a leading cause of global death and disability, and the incidences are expected to increase in the following decades if prevention strategies and successful treatment remain elusive. To date, the etiology of NDs is unclear due to the complexity of the mechanisms of diseases involving genetic and environmental factors, including diet and microbiota. Emerging evidence suggests that changes in diet, alteration of the microbiota, and deregulation of metabolism in the intestinal epithelium influence the inflammatory status of the neurons linked to disease insurgence and progression. This review will describe the leading players of the so-called diet-microbiota-gut-brain (DMGB) axis in the context of NDs. We will report recent findings from studies in model organisms such as rodents and fruit flies that support the role of diets, commensals, and intestinal epithelial functions as an overlooked primary regulator of brain health. We will finish discussing the pivotal role of metabolisms of cellular organelles such as mitochondria and peroxisomes in maintaining the DMGB axis and how alteration of the latter can be used as early disease makers and novel therapeutic targets.
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Affiliation(s)
- Stephanie Makdissi
- Dalhousie University, Department of Microbiology and Immunology, Halifax, NS, Canada
- IWK Health Centre, Department of Pediatrics, Halifax, Canada
| | - Brendon D. Parsons
- Dalhousie University, Department of Microbiology and Immunology, Halifax, NS, Canada
| | - Francesca Di Cara
- Dalhousie University, Department of Microbiology and Immunology, Halifax, NS, Canada
- IWK Health Centre, Department of Pediatrics, Halifax, Canada
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Strope TA, Wilkins HM. Amyloid precursor protein and mitochondria. Curr Opin Neurobiol 2023; 78:102651. [PMID: 36462447 PMCID: PMC9845182 DOI: 10.1016/j.conb.2022.102651] [Citation(s) in RCA: 9] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/22/2022] [Revised: 10/28/2022] [Accepted: 10/31/2022] [Indexed: 12/05/2022]
Abstract
Amyloid Precursor Protein (APP) processing to amyloid beta (Aβ) is a major hallmark of Alzheimer's disease (AD). The amyloid cascade hypothesis postulates that Aβ accumulation and aggregation causes AD, however many therapeutics targeting Aβ have failed recently. Decades of research describe metabolic deficits in AD. Mitochondrial dysfunction is observed in AD subjects within the brain and systemically. APP and γ-secretase are localized to mitochondria. APP can be processed within mitochondria and its localization to mitochondria affects function. Here we discuss the evidence showing APP and γ-secretase localize to mitochondria. We also discuss the implications for the function of APP and its cleavage products in regulating mitochondrial function.
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Affiliation(s)
- Taylor A Strope
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA. https://twitter.com/OneDayDrTay
| | - Heather M Wilkins
- University of Kansas Alzheimer's Disease Center, Kansas City, KS, USA; Department of Biochemistry and Molecular Biology, University of Kansas Medical Center, Kansas City, KS, USA; Department of Neurology University of Kansas Medical Center, Kansas City, KS, USA.
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21
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Jadhav R, Kulkarni YA. Neuroprotective Effect of Quercetin and Memantine against AlCl 3-Induced Neurotoxicity in Albino Wistar Rats. MOLECULES (BASEL, SWITZERLAND) 2023; 28:molecules28010417. [PMID: 36615626 PMCID: PMC9824229 DOI: 10.3390/molecules28010417] [Citation(s) in RCA: 10] [Impact Index Per Article: 10.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 11/15/2022] [Accepted: 12/13/2022] [Indexed: 01/05/2023]
Abstract
Recent evidences indicate that there is a substantial increase in worldwide cases of dementia. Alzheimer's disease is the leading cause of dementia and may contribute to 60-70% of cases. Quercetin is a unique bioflavonoid that has numerous therapeutic benefits such as anti-allergy, anti-ulcer, anti-inflammatory, anti-hypertensive, anti-cancer, immuno-modulatory, anti-infective, antioxidant, acetylcholinesterase inhibitory activity, neuroprotective effects, etc. In the present study, we evaluated the neuroprotective effect of orally administered quercetin with memantine in albino Wistar rats after inducing neurotoxicity through AlCl3 (100 mg/kg, p.o.). Chronic administration of AlCl3 resulted in poor retention of memory and significant oxidative damage. Various behavioral parameters, such as locomotor activity, Morris water maze, elevated plus maze, and passive avoidance test, were assessed on days 21 and 42 of the study. The animals were euthanatized following the completion of the last behavioral assessment. Various oxidative stress parameters were assessed to know the extent of oxidative damage to brain tissue. Quercetin with memantine has shown significant improvement in behavioral studies, inhibition of AChE activity, and reduction in oxidative stress parameters. Histopathological studies assessed for cortex and hippocampus using hematoxylin and eosin (H&E), and Congo red stain demonstrated a reduction in amyloid-β plaque formation after treatment of quercetin with memantine. Immunohistochemistry showed that quercetin with memantine treatment also improved the expression of brain-derived neurotrophic factor (BDNF) and inhibited amyloid-β plaque formation. The present study results demonstrated protective effects of treatment of quercetin with memantine in the neurotoxicity linked to aluminum chloride in albino Wistar rats.
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Jadhav R, Kulkarni YA. Effects of baicalein with memantine on aluminium chloride-induced neurotoxicity in Wistar rats. Front Pharmacol 2023; 14:1034620. [PMID: 36909151 PMCID: PMC9992210 DOI: 10.3389/fphar.2023.1034620] [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: 09/01/2022] [Accepted: 01/11/2023] [Indexed: 02/24/2023] Open
Abstract
Alzheimer's disease is a progressive neurodegenerative condition. It is one of the most common 28 forms of dementia accounting for 60-80% of people suffering from dementia. There are very few medications that are approved for the treatment of Alzheimer's disease. Baicalein, belonging to the flavone subclass of flavonoids, has been reported to have a neuroprotective effect by reducing oxidative stress and neuroinflammation, inhibiting the AChE enzyme, and reducing amyloid protein aggregation and toxicity. Memantine is one of the most important drugs used for treating Alzheimer's disease. The purpose of this work was to study the effect of baicalein with memantine on aluminum chloride-induced neurotoxicity in Wistar rats. Aluminum chloride (100 mg/kg p.o.) was administered for 42 days in male Wistar rats to induce neurotoxicity. Baicalein alone (10 mg/kg) and a combination of baicalein (5 mg/kg and 10 mg/kg) with memantine (20 mg/kg) were administered for 42 days. Treatment of baicalein with memantine showed significant improvement in behavioral parameters. The combination reduced oxidative stress and the formation of β-Amyloid plaques and increased brain-derived neurotrophic factor (BDNF) expression. Based on findings, it can be concluded that treatment with baicalein and memantine may slow the progression of neurodegeneration in rats.
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Affiliation(s)
- Ratnakar Jadhav
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's NMIMS, Mumbai, India
| | - Yogesh A Kulkarni
- Shobhaben Pratapbhai Patel School of Pharmacy & Technology Management, SVKM's NMIMS, Mumbai, India
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Li Y, Wang JZ, Deng YM, Wang K, Yang L, Long C. Amyloid-β Protein Precursor Regulates Electrophysiological Properties in the Hippocampus via Altered Kv1.4 Expression and Function in Mice. J Alzheimers Dis 2023; 92:1241-1256. [PMID: 36872774 DOI: 10.3233/jad-220606] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 03/06/2023]
Abstract
BACKGROUND Amyloid-β protein precursor (AβPP) is enriched in neurons. However, the mechanism underlying AβPP regulation of neuronal activity is poorly understood. Potassium channels are critically involved in neuronal excitability. In hippocampus, A-type potassium channels are highly expressed and involved in determining neuronal spiking. OBJECTIVE We explored hippocampal local field potential (LFP) and spiking in the presence and absence of AβPP, and the potential involvement of an A-type potassium channel. METHODS We used in vivo extracellular recording and whole-cell patch-clamp recording to determine neuronal activity, current density of A-type potassium currents, and western blot to detect changes in related protein levels. RESULTS Abnormal LFP was observed in AβPP-/- mice, including reduced beta and gamma power, and increased epsilon and ripple power. The firing rate of glutamatergic neurons reduced significantly, in line with an increased action potential rheobase. Given that A-type potassium channels regulate neuronal firing, we measured the protein levels and function of two major A-type potassium channels and found that the post-transcriptional level of Kv1.4, but not Kv4.2, was significantly increased in the AβPP-/- mice. This resulted in a marked increase in the peak time of A-type transient outward potassium currents in both glutamatergic and gamma-aminobutyric acid-ergic (GABAergic) neurons. Furthermore, a mechanistic experiment using human embryonic kidney 293 (HEK293) cells revealed that the AβPP deficiency-induced increase in Kv1.4 may not involve protein-protein interaction between AβPP and Kv1.4. CONCLUSION This study suggests that AβPP modulates neuronal firing and oscillatory activity in the hippocampus, and Kv1.4 may be involved in mediating the modulation.
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Affiliation(s)
- Yi Li
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, China
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jin-Zhao Wang
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yue-Ming Deng
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Kun Wang
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Li Yang
- School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Cheng Long
- South China Normal University-Panyu Central Hospital Joint Laboratory of Translational Medical Research, Panyu Central Hospital, Guangzhou, China
- School of Life Sciences, South China Normal University, Guangzhou, China
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Kobro-Flatmoen A, Hormann TM, Gouras G. Intracellular Amyloid-β in the Normal Rat Brain and Human Subjects and Its relevance for Alzheimer's Disease. J Alzheimers Dis 2023; 95:719-733. [PMID: 37574734 PMCID: PMC10578257 DOI: 10.3233/jad-230349] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 07/05/2023] [Indexed: 08/15/2023]
Abstract
BACKGROUND Amyloid-β (Aβ) is a normal product of neuronal activity, including that of the aggregation-prone Aβ42 variant that is thought to cause Alzheimer's disease (AD). Much knowledge about AD comes from studies of transgenic rodents expressing mutated human amyloid-β protein precursor (AβPP) to increase Aβ production or the Aβ42/40 ratio. Yet, little is known about the normal expression of Aβ42 in rodent brains. OBJECTIVE To characterize the brain-wide expression of Aβ42 throughout the life span of outbred Wistar rats, and to relate these findings to brains of human subjects without neurological disease. METHODS Aβ42 immunolabeling of 12 Wistar rat brains (3-18 months of age) and brain sections from six human subjects aged 20-88 years. RESULTS In healthy Wistar rats, we find intracellular Aβ42 (iAβ42) in neurons throughout the brain at all ages, but levels vary greatly between brain regions. The highest levels are in neurons of entorhinal cortex layer II, alongside hippocampal neurons at the CA1/subiculum border. Concerning entorhinal cortex layer II, we find similarly high levels of iAβ42 in the human subjects. CONCLUSION Expression of iAβ42 in healthy Wistar rats predominates in the same structures where iAβ accumulates and Aβ plaques initially form in the much used, Wistar based McGill-R-Thy1-APP rat model for AD. The difference between wild-type Wistar rats and these AD model rats, with respect to Aβ42, is therefore quantitative rather that qualitative. This, taken together with our human results, indicate that the McGill rat model in fact models the underlying wild-type neuronal population-specific vulnerability to Aβ42 accumulation.
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Affiliation(s)
- Asgeir Kobro-Flatmoen
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
- K.G. Jebsen Centre for Alzheimer’s Disease, NTNU, Trondheim, Norway
| | - Thea Meier Hormann
- Kavli Institute for Systems Neuroscience, Norwegian University of Science and Technology, Trondheim, Norway
| | - Gunnar Gouras
- Department of Experimental Medical Science, Experimental Dementia Research Unit, Lund University, Lund, Sweden
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25
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Hu L, Zhang L, Li Q, Liu H, Xu T, Zhao N, Han X, Xu S, Zhao X, Zhang C. Genome-wide analysis of CNVs in three populations of Tibetan sheep using whole-genome resequencing. Front Genet 2022; 13:971464. [PMID: 36160022 PMCID: PMC9490000 DOI: 10.3389/fgene.2022.971464] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2022] [Accepted: 08/23/2022] [Indexed: 01/29/2023] Open
Abstract
Copy number variation (CNV), an important source of genomic structural variation, can disturb genetic structure, dosage, regulation and expression, and is associated with phenotypic diversity and adaptation to local environments in mammals. In the present study, 24 resequencing datasets were used to characterize CNVs in three ecotypic populations of Tibetan sheep and assess CNVs related to domestication and adaptation in Qinghai-Tibetan Plateau. A total of 87,832 CNV events accounting for 0.3% of the sheep genome were detected. After merging the overlapping CNVs, 2777 CNV regions (CNVRs) were obtained, among which 1098 CNVRs were shared by the three populations. The average length of these CNVRs was more than 3 kb, and duplication events were more frequent than deletions. Functional analysis showed that the shared CNVRs were significantly enriched in 56 GO terms and 18 KEGG pathways that were mainly concerned with ABC transporters, olfactory transduction and oxygen transport. Moreover, 188 CNVRs overlapped with 97 quantitative trait loci (QTLs), such as growth and carcass QTLs, immunoglobulin QTLs, milk yield QTLs and fecal egg counts QTLs. PCDH15, APP and GRID2 overlapped with body weight QTLs. Furthermore, Vst analysis showed that RUNX1, LOC101104348, LOC105604082 and PAG11 were highly divergent between Highland-type Tibetan Sheep (HTS) and Valley-type Tibetan sheep (VTS), and RUNX1 and LOC101111988 were significantly differentiated between VTS and Oura-type Tibetan sheep (OTS). The duplication of RUNX1 may facilitate the hypoxia adaptation of OTS and HTS in Qinghai-Tibetan Plateau, which deserves further research in detail. In conclusion, for the first time, we represented the genome-wide distribution characteristics of CNVs in Tibetan sheep by resequencing, and provided a valuable genetic variation resource, which will facilitate the elucidation of the genetic basis underlying the distinct phenotypic traits and local adaptation of Tibetan sheep.
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Affiliation(s)
- Linyong Hu
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Liangzhi Zhang
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Qi Li
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Hongjin Liu
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Tianwei Xu
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Na Zhao
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Xueping Han
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
- Technology Extension Service of Animal Husbandry of Qinghai, Xining, China
| | - Shixiao Xu
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Xinquan Zhao
- Key Laboratory of Adaptation and Evolution of Plateau Biota, Northwest Institute of Plateau Biology, Chinese Academy of Sciences, Xining, China
| | - Cunfang Zhang
- State Key Laboratory of Plateau Ecology and Agriculture, Qinghai University, Xining, China
- *Correspondence: Cunfang Zhang,
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Cho Y, Bae HG, Okun E, Arumugam TV, Jo DG. Physiology and pharmacology of amyloid precursor protein. Pharmacol Ther 2022; 235:108122. [PMID: 35114285 DOI: 10.1016/j.pharmthera.2022.108122] [Citation(s) in RCA: 25] [Impact Index Per Article: 12.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/09/2021] [Revised: 01/17/2022] [Accepted: 01/25/2022] [Indexed: 02/06/2023]
Abstract
Amyloid precursor protein (APP) is an evolutionarily conserved transmembrane protein and a well-characterized precursor protein of amyloid-beta (Aβ) peptides, which accumulate in the brains of individuals with Alzheimer's disease (AD)-related pathologies. Aβ has been extensively investigated since the amyloid hypothesis in AD was proposed. Besides Aβ, previous studies on APP and its proteolytic cleavage products have suggested their diverse pathological and physiological functions. However, their roles still have not been thoroughly understood. In this review, we extensively discuss the evolutionarily-conserved biology of APP, including its structure and processing pathway, as well as recent findings on the physiological roles of APP and its fragments in the central nervous system and peripheral nervous system. We have also elaborated upon the current status of APP-targeted therapeutic approaches for AD treatment by discussing inhibitors of several proteases participating in APP processing, including α-, β-, and γ-secretases. Finally, we have highlighted the future perspectives pertaining to further research and the potential clinical role of APP.
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Affiliation(s)
- Yoonsuk Cho
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea
| | - Han-Gyu Bae
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea
| | - Eitan Okun
- The Leslie and Susan Gonda Multidisciplinary Brain Research Center, Bar-Ilan University, Ramat Gan 5290002, Israel; The Mina and Everard Goodman Faculty of Life Sciences, Bar-Ilan University, Ramat Gan 5290002, Israel; The Pauld Feder Laboratory on Alzheimer's Disease Research, Israel
| | - Thiruma V Arumugam
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea; School of Life Sciences, La Trobe University, Bundoora, Victoria, Australia.
| | - Dong-Gyu Jo
- School of Pharmacy, Sungkyunkwan University, Suwon 16419, South Korea; Samsung Advanced Institute for Health Sciences and Technology, Sungkyunkwan University, Seoul 06351, South Korea; Biomedical Institute for Convergence, Sungkyunkwan University, Suwon 16419, South Korea.
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27
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Kalle J, Pontus W, Lenka N, Simon S, Ann B, Gunnar B, Kaj B, Henrik Z, Markus A. Cerebrospinal fluid amyloid precursor protein as a potential biomarker of fatigue in multiple sclerosis: A pilot study. Mult Scler Relat Disord 2022; 63:103846. [DOI: 10.1016/j.msard.2022.103846] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/28/2021] [Revised: 04/15/2022] [Accepted: 05/01/2022] [Indexed: 11/28/2022]
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Peripheral Aβ acts as a negative modulator of insulin secretion. Proc Natl Acad Sci U S A 2022; 119:e2117723119. [PMID: 35290109 PMCID: PMC8944757 DOI: 10.1073/pnas.2117723119] [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] [Indexed: 11/18/2022] Open
Abstract
The cerebral accumulation of amyloid β (Aβ) is a hallmark of Alzheimer’s disease (AD). While type 2 diabetes mellitus is known to be a risk factor for AD, the underlying mechanisms remain unclear. In the present study, we demonstrate that plasma Aβ is produced from glucose- and insulin-susceptible peripheral tissues, such as the pancreas, adipose tissues, skeletal muscles, and liver, to inhibit insulin secretion from islet β-cells. Our findings suggest a physiological role of peripheral Aβ in glucose and insulin metabolism and a possible mechanism linking diabetes to AD. In addition, although plasma Aβ levels are currently used as a diagnostic biomarker of AD, our data suggest they should be used with caution. Type 2 diabetes mellitus is known to be a risk factor for Alzheimer’s disease (AD), but the underlying mechanisms remain unclear. In AD, the cerebral accumulation of amyloid β (Aβ) triggers a pathological cascade leading to neurodegeneration. Plasma Aβ levels are thought to reflect the brain amyloid pathology and currently used as a diagnostic biomarker of AD. However, amyloid precursor protein and Aβ-generating enzymes, β- and γ-secretases, are widely expressed in various peripheral tissues. Previous reports have shown that glucose and insulin loading cause a transient increase of plasma Aβ in mice and humans. These findings led us to speculate that plasma Aβ is produced from glucose- and insulin-susceptible peripheral tissues to play a role in glucose and insulin metabolism. To test this hypothesis, we investigated the effects of glucose and insulin on Aβ secretion and the effect of Aβ on insulin secretion in vivo, ex vivo, and in vitro. Aβ was found to be secreted from β-cells of the pancreas along with insulin upon glucose stimulation. Upon insulin stimulation, Aβ was secreted from cells of insulin-targeted organs, such as adipose tissues, skeletal muscles, and the liver, along with their organokines. Furthermore, Aβ inhibited the glucose-triggered insulin secretion from β-cells, slowing down glucose clearance from the blood. These results suggest that peripheral Aβ acts as a negative modulator of insulin secretion. Our findings provide a possible mechanism linking diabetes to AD and call attention to how plasma Aβ levels are used in AD diagnosis.
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Finding New Ways How to Control BACE1. J Membr Biol 2022; 255:293-318. [PMID: 35305135 DOI: 10.1007/s00232-022-00225-1] [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: 02/02/2022] [Accepted: 02/24/2022] [Indexed: 01/18/2023]
Abstract
Recently, all applications of BACE1 inhibitors failed as therapeutical targets for Alzheimer´s disease (AD) due to severe side effects. Therefore, alternative ways for treatment development are a hot research topic. The present analysis investigates BACE1 protein-protein interaction networks and attempts to solve the absence of complete knowledge about pathways involving BACE1. A bioinformatics analysis matched the functions of the non-substrate interaction network with Voltage-gated potassium channels, which also appear as top priority protein nodes. Targeting BACE1 interactions with PS1 and GGA-s, blocking of BACE1 access to APP by BRI3 and RTN-s, activation of Wnt signaling and upregulation of β-catenin, and brain delivery of the extracellular domain of p75NTR, are the main alternatives to the use of BACE 1 inhibitors highlighted by the analysis. The pathway enrichment analysis also emphasized substrates and substrate candidates with essential biological functions, which cleavage must remain controlled. They include ephrin receptors, ROBO1, ROBO2, CNTN-s, CASPR-s, CD147, CypB, TTR, APLP1/APLP2, NRXN-s, and PTPR-s. The analysis of the interaction subnetwork of BACE1 functionally related to inflammation identified a connection to three cardiomyopathies, which supports the hypothesis of the common molecular mechanisms with AD. A lot of potential shows the regulation of BACE1 activity through post-translational modifications. The interaction network of BACE1 and its phosphorylation enzyme CSNK1D functionally match the Circadian clock, p53, and Hedgehog signaling pathways. The regulation of BACE1 glycosylation could be achieved through N-acetylglucosamine transferases, α-(1→6)-fucosyltransferase, β-galactoside α-(2→6)-sialyltransferases, galactosyltransferases, and mannosidases suggested by the interaction network analysis of BACE1-MGAT3. The present analysis proposes possibilities for the alternative control of AD pathology.
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Gabriele RMC, Abel E, Fox NC, Wray S, Arber C. Knockdown of Amyloid Precursor Protein: Biological Consequences and Clinical Opportunities. Front Neurosci 2022; 16:835645. [PMID: 35360155 PMCID: PMC8964081 DOI: 10.3389/fnins.2022.835645] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/14/2021] [Accepted: 02/18/2022] [Indexed: 12/29/2022] Open
Abstract
Amyloid precursor protein (APP) and its cleavage fragment Amyloid-β (Aβ) have fundamental roles in Alzheimer's disease (AD). Genetic alterations that either increase the overall dosage of APP or alter its processing to favour the generation of longer, more aggregation prone Aβ species, are directly causative of the disease. People living with one copy of APP are asymptomatic and reducing APP has been shown to lower the relative production of aggregation-prone Aβ species in vitro. For these reasons, reducing APP expression is an attractive approach for AD treatment and prevention. In this review, we will describe the structure and the known functions of APP and go on to discuss the biological consequences of APP knockdown and knockout in model systems. We highlight progress in therapeutic strategies to reverse AD pathology via reducing APP expression. We conclude that new technologies that reduce the dosage of APP expression may allow disease modification and slow clinical progression, delaying or even preventing onset.
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Affiliation(s)
- Rebecca M. C. Gabriele
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Emily Abel
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, United Kingdom,UK Dementia Research Institute at University College London (UCL), Queen Square Institute of Neurology, London, United Kingdom
| | - Nick C. Fox
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, United Kingdom,UK Dementia Research Institute at University College London (UCL), Queen Square Institute of Neurology, London, United Kingdom
| | - Selina Wray
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, United Kingdom
| | - Charles Arber
- Department of Neurodegenerative Disease, Queen Square Institute of Neurology, University College London, London, United Kingdom,*Correspondence: Charles Arber,
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Klonarakis M, De Vos M, Woo E, Ralph L, Thacker JS, Gil-Mohapel J. The three sisters of fate: Genetics, pathophysiology and outcomes of animal models of neurodegenerative diseases. Neurosci Biobehav Rev 2022; 135:104541. [DOI: 10.1016/j.neubiorev.2022.104541] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/03/2021] [Revised: 11/28/2021] [Accepted: 01/13/2022] [Indexed: 02/07/2023]
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32
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Vigneswaran J, Muthukumar SA, Shafras M, Pant G. An insight into Alzheimer’s disease and its on-setting novel genes. THE EGYPTIAN JOURNAL OF NEUROLOGY, PSYCHIATRY AND NEUROSURGERY 2021. [DOI: 10.1186/s41983-021-00420-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/10/2022] Open
Abstract
AbstractAccording to the World Health Organisation, as of 2019, globally around 50 million people suffer from dementia, with approximately another 10 million getting added to the list every year, wherein Alzheimer’s disease (AD) stands responsible for almost a whopping 60–70% for the existing number of cases. Alzheimer’s disease is one of the progressive, cognitive-declining, age-dependent, neurodegenerative diseases which is distinguished by histopathological symptoms, such as formation of amyloid plaque, senile plaque, neurofibrillary tangles, etc. Majorly four vital transcripts are identified in the AD complications which include Amyloid precursor protein (APP), Apolipoprotein E (ApoE), and two multi-pass transmembrane domain proteins—Presenilin 1 and 2. In addition, the formation of the abnormal filaments such as amyloid beta (Aβ) and tau and their tangling with some necessary factors contributing to the formation of plaques, neuroinflammation, and apoptosis which in turn leads to the emergence of AD. Although multiple molecular mechanisms have been elucidated so far, they are still counted as hypotheses ending with neuronal death on the basal forebrain and hippocampal area which results in AD. This review article is aimed at addressing the overview of the molecular mechanisms surrounding AD and the functional forms of the genes associated with it.
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Lennon MJ, Rigney G, Raymont V, Sachdev P. Genetic Therapies for Alzheimer's Disease: A Scoping Review. J Alzheimers Dis 2021; 84:491-504. [PMID: 34569966 DOI: 10.3233/jad-215145] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Effective, disease modifying therapies for Alzheimer's disease (AD) remain a quandary, following a panoply of expensive failures in human clinical trials. Given the stagnation in therapeutics, alternative approaches are needed. Recent successes of genetic therapies in other neurodegenerative diseases may highlight the way forward. This scoping review explores suggested targets of genetic therapy in AD, with a focus on vector-based approaches in pre-clinical and clinical trials. Putative targets of genetic therapies tested in pre-clinical trials include amyloid pathway intermediates and enzymes modulation, tau protein downregulation, APOE4 downregulation and APOE2 upregulation, neurotrophin expression (nerve growth factor (NGF) and brain-derived neurotrophic factor), and inflammatory cytokine alteration, among several other approaches. There have been three completed human clinical trials for genetic therapy in AD patients, all of which upregulated NGF in AD patients, showing some mixed evidence of benefit. Several impediments remain to be surpassed before genetic therapies can be successfully applied to AD, including the challenge of delivering monogenic genetic therapies for complex polygenic disorders, risks in the dominant delivery method (intracranial injection), stability of genetic therapies in vivo, poor translatability of pre-clinical AD models, and the expense of genetic therapy production. Genetic therapies represent an exciting opportunity within the world of AD therapeutics, but clinical applications likely remain a long term, rather than short term, possibility.
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Affiliation(s)
- Matthew J Lennon
- Department of Physiology, Anatomy and Genetics, Sherrington Building, University of Oxford, Oxford, UK.,Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia
| | - Grant Rigney
- Department of Psychiatry, University of Oxford, Oxford, UK
| | | | - Perminder Sachdev
- Centre for Healthy Brain Ageing (CHeBA), School of Psychiatry, Faculty of Medicine, University of New South Wales, Sydney, NSW, Australia.,Neuropsychiatric Institute, Prince of Wales Hospital, Sydney, NSW, Australia
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Gadhave K, Kumar D, Uversky VN, Giri R. A multitude of signaling pathways associated with Alzheimer's disease and their roles in AD pathogenesis and therapy. Med Res Rev 2021; 41:2689-2745. [PMID: 32783388 PMCID: PMC7876169 DOI: 10.1002/med.21719] [Citation(s) in RCA: 18] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Revised: 07/13/2020] [Accepted: 07/29/2020] [Indexed: 02/06/2023]
Abstract
The exact molecular mechanisms associated with Alzheimer's disease (AD) pathology continue to represent a mystery. In the past decades, comprehensive data were generated on the involvement of different signaling pathways in the AD pathogenesis. However, the utilization of signaling pathways as potential targets for the development of drugs against AD is rather limited due to the immense complexity of the brain and intricate molecular links between these pathways. Therefore, finding a correlation and cross-talk between these signaling pathways and establishing different therapeutic targets within and between those pathways are needed for better understanding of the biological events responsible for the AD-related neurodegeneration. For example, autophagy is a conservative cellular process that shows link with many other AD-related pathways and is crucial for maintenance of the correct cellular balance by degrading AD-associated pathogenic proteins. Considering the central role of autophagy in AD and its interplay with many other pathways, the finest therapeutic strategy to fight against AD is the use of autophagy as a target. As an essential step in this direction, this comprehensive review represents recent findings on the individual AD-related signaling pathways, describes key features of these pathways and their cross-talk with autophagy, represents current drug development, and introduces some of the multitarget beneficial approaches and strategies for the therapeutic intervention of AD.
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Affiliation(s)
- Kundlik Gadhave
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
| | - Deepak Kumar
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
| | - Vladimir N. Uversky
- Department of Molecular Medicine and Byrd Alzheimer’s Research Institute, Morsani College of Medicine, University of South Florida, Tampa, Florida, United States of America
- Laboratory of New Methods in Biology, Institute for Biological Instrumentation, Russian Academy of Sciences, Pushchino, Moscow Region, Russia
| | - Rajanish Giri
- School of Basic Sciences, Indian Institute of Technology Mandi, Kamand, Himachal Pradesh, 175005, India
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35
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Oli V, Gupta R, Kumar P. FOXO and related transcription factors binding elements in the regulation of neurodegenerative disorders. J Chem Neuroanat 2021; 116:102012. [PMID: 34400291 DOI: 10.1016/j.jchemneu.2021.102012] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2021] [Revised: 07/16/2021] [Accepted: 08/07/2021] [Indexed: 12/16/2022]
Abstract
Neurodegenerative diseases, such as Alzheimer's disease, Parkinson's disease, Huntington's disease, amyotrophic lateral sclerosis, and others, are characterized by progressive loss of neuronal cells, which causes memory impairment and cognitive decline. Mounting evidence demonstrated the possible implications of diverse biological processes, namely oxidative stress, mitochondrial dysfunction, aberrant cell cycle re-entry, post-translational modifications, protein aggregation, impaired proteasome dysfunction, autophagy, and many others that cause neuronal cell death. The condition worsens as there is no effective treatment for such diseases due to their complex pathogenesis and mechanism. Mounting evidence demonstrated the role of regulatory transcription factors, such as NFκβ, FoxO, Myc, CREB, and others that regulate the biological processes and diminish the disease progression and pathogenesis. Studies demonstrated that forkhead box O (FoxO) transcription factors had been implicated in the regulation of aging and longevity. Further, the functions of FoxO proteins are regulated by different post-translational modifications (PTMs), namely acetylation, and ubiquitination. Various studies concluded that FoxO proteins exert both neuroprotective and neurotoxic properties depending on their regulation mechanism and activity in the brain. Thus, understanding the nature of FoxO expression and activity in the brain will help develop effective therapeutic strategies. Herein, firstly, we discuss the role of FoxO protein in cell cycle regulation and cell proliferation, followed by the regulation of FoxO proteins through acetylation and ubiquitination. We also briefly explain the activity and expression pattern of FoxO proteins in the neuronal cells and explain the mechanism through which FoxO proteins are rescued from oxidative stress-induced neurotoxicity. Later on, we present a detailed view of the implication of FoxO proteins in neurodegenerative disease and FoxO proteins as an effective therapeutic target.
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Affiliation(s)
- Vaibhav Oli
- Molecular Neuroscience and Functional Genomics Laboratory, Delhi Technological University (Formerly Delhi College of Engineering), India
| | - Rohan Gupta
- Molecular Neuroscience and Functional Genomics Laboratory, Delhi Technological University (Formerly Delhi College of Engineering), India
| | - Pravir Kumar
- Molecular Neuroscience and Functional Genomics Laboratory, Delhi Technological University (Formerly Delhi College of Engineering), India.
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Loss of APP in mice increases thigmotaxis and is associated with elevated brain expression of IL-13 and IP-10/CXCL10. Physiol Behav 2021; 240:113533. [PMID: 34293404 DOI: 10.1016/j.physbeh.2021.113533] [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: 04/16/2021] [Revised: 07/13/2021] [Accepted: 07/16/2021] [Indexed: 11/23/2022]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder that leads to memory loss and is often accompanied by increased anxiety. Although AD is a heterogeneous disease, dysregulation of inflammatory pathways is a consistent event. Interestingly, the amyloid precursor protein (APP), which is the source of the amyloid peptide Aβ, is also necessary for the efficient regulation of the innate immune response. Here, we hypothesize that loss of APP function in mice would lead to cognitive loss and anxiety behavior, both of which are typically present in AD, as well as changes in the expression of inflammatory mediators. To test this hypothesis, we performed open field, Y-maze and novel object recognition tests on 12-18-week-old male and female wildtype and AppKO mice to measure thigmotaxis, short-term spatial memory and long-term recognition memory. We then performed a quantitative multiplexed immunoassay to measure levels of 32 cytokines/chemokines associated with AD and anxiety. Our results showed that AppKO mice, compared to wildtype controls, experienced increased thigmotactic behavior but no memory impairments, and this phenotype correlated with increased IP-10 and IL-13 levels. Future studies will determine whether dysregulation of these inflammatory mediators contributes to pathogenesis in AD.
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37
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Augustin V, Kins S. Fe65: A Scaffolding Protein of Actin Regulators. Cells 2021; 10:cells10071599. [PMID: 34202290 PMCID: PMC8304848 DOI: 10.3390/cells10071599] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/02/2021] [Revised: 06/19/2021] [Accepted: 06/21/2021] [Indexed: 01/19/2023] Open
Abstract
The scaffolding protein family Fe65, composed of Fe65, Fe65L1, and Fe65L2, was identified as an interaction partner of the amyloid precursor protein (APP), which plays a key function in Alzheimer’s disease. All three Fe65 family members possess three highly conserved interaction domains, forming complexes with diverse binding partners that can be assigned to different cellular functions, such as transactivation of genes in the nucleus, modulation of calcium homeostasis and lipid metabolism, and regulation of the actin cytoskeleton. In this article, we rule out putative new intracellular signaling mechanisms of the APP-interacting protein Fe65 in the regulation of actin cytoskeleton dynamics in the context of various neuronal functions, such as cell migration, neurite outgrowth, and synaptic plasticity.
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38
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Steubler V, Erdinger S, Back MK, Ludewig S, Fässler D, Richter M, Han K, Slomianka L, Amrein I, von Engelhardt J, Wolfer DP, Korte M, Müller UC. Loss of all three APP family members during development impairs synaptic function and plasticity, disrupts learning, and causes an autism-like phenotype. EMBO J 2021; 40:e107471. [PMID: 34008862 PMCID: PMC8204861 DOI: 10.15252/embj.2020107471] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/08/2020] [Revised: 03/29/2021] [Accepted: 04/01/2021] [Indexed: 12/15/2022] Open
Abstract
The key role of APP for Alzheimer pathogenesis is well established. However, perinatal lethality of germline knockout mice lacking the entire APP family has so far precluded the analysis of its physiological functions for the developing and adult brain. Here, we generated conditional APP/APLP1/APLP2 triple KO (cTKO) mice lacking the APP family in excitatory forebrain neurons from embryonic day 11.5 onwards. NexCre cTKO mice showed altered brain morphology with agenesis of the corpus callosum and disrupted hippocampal lamination. Further, NexCre cTKOs revealed reduced basal synaptic transmission and drastically reduced long-term potentiation that was associated with reduced dendritic length and reduced spine density of pyramidal cells. With regard to behavior, lack of the APP family leads not only to severe impairments in a panel of tests for learning and memory, but also to an autism-like phenotype including repetitive rearing and climbing, impaired social communication, and deficits in social interaction. Together, our study identifies essential functions of the APP family during development, for normal hippocampal function and circuits important for learning and social behavior.
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Affiliation(s)
- Vicky Steubler
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Susanne Erdinger
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Michaela K Back
- Institute of PathophysiologyFocus Program Translational Neuroscience (FTN)University Medical Center of the Johannes Gutenberg University MainzMainzGermany
| | - Susann Ludewig
- Division of Cellular NeurobiologyZoological Institute, TU BraunschweigBraunschweigGermany
- Helmholtz Centre for Infection Research, Neuroinflammation and Neurodegeneration GroupBraunschweigGermany
| | - Dominique Fässler
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Max Richter
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Kang Han
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
| | - Lutz Slomianka
- Institute of Anatomy and Zurich Center for Integrative Human PhysiologyUniversity of ZurichZurichSwitzerland
| | - Irmgard Amrein
- Institute of Anatomy and Zurich Center for Integrative Human PhysiologyUniversity of ZurichZurichSwitzerland
| | - Jakob von Engelhardt
- Institute of PathophysiologyFocus Program Translational Neuroscience (FTN)University Medical Center of the Johannes Gutenberg University MainzMainzGermany
| | - David P Wolfer
- Institute of Anatomy and Zurich Center for Integrative Human PhysiologyUniversity of ZurichZurichSwitzerland
- Institute of Human Movement SciencesETH ZurichZurichSwitzerland
| | - Martin Korte
- Division of Cellular NeurobiologyZoological Institute, TU BraunschweigBraunschweigGermany
- Helmholtz Centre for Infection Research, Neuroinflammation and Neurodegeneration GroupBraunschweigGermany
| | - Ulrike C Müller
- Department of Functional GenomicsInstitute of Pharmacy and Molecular BiotechnologyHeidelberg UniversityHeidelbergGermany
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Liang Y, Raven F, Ward JF, Zhen S, Zhang S, Sun H, Miller SJ, Choi SH, Tanzi RE, Zhang C. Upregulation of Alzheimer's Disease Amyloid-β Protein Precursor in Astrocytes Both in vitro and in vivo. J Alzheimers Dis 2021; 76:1071-1082. [PMID: 32597805 DOI: 10.3233/jad-200128] [Citation(s) in RCA: 17] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
BACKGROUND The amyloid cascade hypothesis of Alzheimer's disease (AD) posits that amyloid-β (Aβ) protein accumulation underlies the pathogenesis of the disease by leading to the formation of amyloid plaques, a pathologic hallmark of AD. Aβ is a proteolytic product of amyloid-β protein precursor (AβPP; APP), which is expressed in both neurons and astrocytes. Although considerable evidence shows that astrocytes may play critical roles in the pathogenesis of AD, the longitudinal changes of amyloid plaques in relationship to AβPP expression in astrocytes and cellular consequences are largely unknown. OBJECTIVE Here, we aimed to investigate astrocyte-related pathological changes of Aβ and AβPP using immunohistochemistry and biochemical studies in both animal and cell models. METHODS/RESULTS We utilized 5XFAD transgenic mice and found age-dependent upregulation of AβPP in astrocytes demonstrated with astrocytic reactive properties, which followed appearance of amyloid plaques in the brain. We also observed that AβPP proteins presented well-defined punctate immuno reactivity in young animals, whereas AβPP staining showed disrupted structures surrounding amyloid plaques in older mice. Moreover, we utilized astrocyte cell models and showed that pretreatment of Aβ42 resulted in downstream astrocyte autonomous changes, including up regulation in AβPP and BACE1 levels, as well as prolonged amyloidogenesis that could be reduced by pharmacological inhibition of BACE1. CONCLUSION Collectively, our results show that age-dependent AβPP up regulation in astrocytes is a key feature in AD, which will not only provide novel insights for understanding AD progression, but also may offer new therapeutic strategies for treating AD.
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Affiliation(s)
- Yingxia Liang
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA.,Department of Anesthesiology, Weifang Medical University, Weifang, Shandong, China
| | - Frank Raven
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Joseph F Ward
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Sherri Zhen
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Siyi Zhang
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Haoqi Sun
- Department of Neurology, Massachusetts General Hospital, Boston, MA, USA
| | - Sean J Miller
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Se Hoon Choi
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Rudolph E Tanzi
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
| | - Can Zhang
- Genetics and Aging Research Unit, McCance Center for Brain Health, MassGeneral Institute for Neurodegenerative Diseases (MIND), Department of Neurology, Massachusetts General Hospital and Harvard Medical School, Charlestown, MA, USA
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40
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Daoutsali E, Hailu TT, Buijsen RAM, Pepers BA, van der Graaf LM, Verbeek MM, Curtis D, de Vlaam T, van Roon-Mom WMC. Antisense Oligonucleotide-Induced Amyloid Precursor Protein Splicing Modulation as a Therapeutic Approach for Dutch-Type Cerebral Amyloid Angiopathy. Nucleic Acid Ther 2021; 31:351-363. [PMID: 34061681 PMCID: PMC8823675 DOI: 10.1089/nat.2021.0005] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022] Open
Abstract
Dutch-type cerebral amyloid angiopathy (D-CAA) is a monogenic form of cerebral amyloid angiopathy and is inherited in an autosomal dominant manner. The disease is caused by a point mutation in exon 17 of the amyloid precursor protein (APP) gene that leads to an amino acid substitution at codon 693. The mutation is located within the amyloid beta (Aβ) domain of APP, and leads to accumulation of toxic Aβ peptide in and around the cerebral vasculature. We have designed an antisense oligonucleotide (AON) approach that results in skipping of exon 17, generating a shorter APP isoform that lacks part of the Aβ domain and the D-CAA mutation. We demonstrate efficient AON-induced skipping of exon 17 at RNA level and the occurrence of a shorter APP protein isoform in three different cell types. This resulted in a reduction of Aβ40 in neuronally differentiated, patient-derived induced pluripotent stem cells. AON-treated wild-type mice showed successful exon skipping on RNA and protein levels throughout the brain. These results illustrate APP splice modulation as a promising therapeutic approach for D-CAA.
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Affiliation(s)
- Elena Daoutsali
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | | | - Ronald A M Buijsen
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Barry A Pepers
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Linda M van der Graaf
- Department of Human Genetics, Leiden University Medical Center, Leiden, the Netherlands
| | - Marcel M Verbeek
- Departments of Neurology and Laboratory Medicine, Radboud Alzheimer Centre, Radboud University Medical Center, Donders Institute for Brain, Cognition and Behaviour, Nijmegen, the Netherlands
| | - Daniel Curtis
- Amylon Therapeutics, Leiden, the Netherlands.,Atalanta Therapeutics, Boston, Massachusetts, USA
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Amyloid-Beta Mediates Homeostatic Synaptic Plasticity. J Neurosci 2021; 41:5157-5172. [PMID: 33926999 PMCID: PMC8211553 DOI: 10.1523/jneurosci.1820-20.2021] [Citation(s) in RCA: 25] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/15/2020] [Revised: 03/02/2021] [Accepted: 03/28/2021] [Indexed: 12/25/2022] Open
Abstract
The physiological role of the amyloid-precursor protein (APP) is insufficiently understood. Recent work has implicated APP in the regulation of synaptic plasticity. Substantial evidence exists for a role of APP and its secreted ectodomain APPsα in Hebbian plasticity. Here, we addressed the relevance of APP in homeostatic synaptic plasticity using organotypic tissue cultures prepared from APP -/- mice of both sexes. In the absence of APP, dentate granule cells failed to strengthen their excitatory synapses homeostatically. Homeostatic plasticity is rescued by amyloid-β and not by APPsα, and it is neither observed in APP+/+ tissue treated with β- or γ-secretase inhibitors nor in synaptopodin-deficient cultures lacking the Ca2+-dependent molecular machinery of the spine apparatus. Together, these results suggest a role of APP processing via the amyloidogenic pathway in homeostatic synaptic plasticity, representing a function of relevance for brain physiology as well as for brain states associated with increased amyloid-β levels.
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42
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Slater C, Wang Q. Alzheimer's disease: An evolving understanding of noradrenergic involvement and the promising future of electroceutical therapies. Clin Transl Med 2021; 11:e397. [PMID: 33931975 PMCID: PMC8087948 DOI: 10.1002/ctm2.397] [Citation(s) in RCA: 19] [Impact Index Per Article: 6.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/11/2020] [Revised: 04/05/2021] [Accepted: 04/11/2021] [Indexed: 02/06/2023] Open
Abstract
Alzheimer's disease (AD) poses a significant global health concern over the next several decades. Multiple hypotheses have been put forth that attempt to explain the underlying pathophysiology of AD. Many of these are briefly reviewed here, but to-date no disease-altering therapy has been achieved. Despite this, recent work expanding on the role of noradrenergic system dysfunction in both the pathogenesis and symptomatic exacerbation of AD has shown promise. The role norepinephrine (NE) plays in AD remains complicated but pre-tangle tau has consistently been shown to arise in the locus coeruleus (LC) of patients with AD decades before symptom onset. The current research reviewed here indicates NE can facilitate neuroprotective and memory-enhancing effects through β adrenergic receptors, while α2A adrenergic receptors may exacerbate amyloid toxicity through a contribution to tau hyperphosphorylation. AD appears to involve a disruption in the balance between these two receptors and their various subtypes. There is also a poorly characterized interplay between the noradrenergic and cholinergic systems. LC deterioration leads to maladaptation in the remaining LC-NE system and subsequently inhibits cholinergic neuron function, eventually leading to the classic cholinergic disruption seen in AD. Understanding AD as a dysfunctional noradrenergic system, provides new avenues for the use of advanced neural stimulation techniques to both study and therapeutically target the earliest stages of neuropathology. Direct LC stimulation and non-invasive vagus nerve stimulation (VNS) have both demonstrated potential use as AD therapeutics. Significant work remains, though, to better understand the role of the noradrenergic system in AD and how electroceuticals can provide disease-altering treatments.
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Affiliation(s)
- Cody Slater
- Department of Biomedical EngineeringColumbia UniversityNew YorkNew YorkUSA
- Vagelos College of Physicians and SurgeonsColumbia UniversityNew YorkNew YorkUSA
| | - Qi Wang
- Department of Biomedical EngineeringColumbia UniversityNew YorkNew YorkUSA
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Chen XQ, Das U, Park G, Mobley WC. Normal levels of KIF5 but reduced KLC1 levels in both Alzheimer disease and Alzheimer disease in Down syndrome: evidence suggesting defects in anterograde transport. Alzheimers Res Ther 2021; 13:59. [PMID: 33691783 PMCID: PMC7945332 DOI: 10.1186/s13195-021-00796-6] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2020] [Accepted: 02/22/2021] [Indexed: 12/31/2022]
Abstract
BACKGROUND Impaired axonal transport may contribute to the pathogenesis of neurodegenerative diseases, including Alzheimer's disease (AD) and Down syndrome (DS). Axonal transport is a complex process in which specific motor proteins move cargoes to and from neuronal cell bodies and their processes. Inconsistent reports point to the changes in AD in the levels of the classical anterograde motor protein kinesin family member 5 (KIF5) and the primary neuronal KIF regulator kinesin light chain 1 (KLC1), raising the possibility that anterograde transport is compromised in AD. METHODS AND MATERIALS To address inconsistencies and determine if the shared pathologies in AD and elderly DS subjects with dementia (AD in DS; AD-DS) extend to the changes in KIF5 and KLC1, we measured the levels of all the three KIF5 family members and KLC1 in the AD and AD-DS frontal cortex and AD temporal cortex and cerebellum in samples taken with a short postmortem interval. To support future studies to explore the cell biological basis for any changes detected, we also examined the levels of these proteins in the brains of young and aged adult mice in the Dp (16)1Yey/+ (Dp16) mouse model of DS and J20 mouse model of AD. RESULTS There were no changes in comparison with controls in KIF5 family members in either the AD or AD-DS samples when normalized to either β-actin or glyceraldehyde-3-phosphate dehydrogenase (GAPDH). Interestingly, however, samples from control brains as well as from AD and AD-DS demonstrated strong positive correlations between the levels of KIF5 family members, suggesting positive co-regulated expression. Importantly, while earlier reports pointed to a negative correlation between the levels of the amyloid precursor protein (APP) and KIF5A levels, we found the opposite to be true in AD-DS; this was especially striking given triplication of the APP gene, with increased APP protein levels. AD and control samples showed positive correlations between fl-hAPP and KIF5 members, but they were less consistent. In contrast to the findings for KIF5, the levels of KLC1 were downregulated in the frontal cortex of both AD and AD-DS brains; interestingly, this change was not seen in the AD temporal cortex or cerebellum. As postmortem interval has a negative effect on the levels of KLC1, but not KIF5 members, we analyzed a subset of samples with a very short postmortem interval (PMI) (≤ 6 h), a PMI that was not significantly correlated with the levels of KLC1 in either AD or AD-DS samples; we confirmed the presence of a statistically significant reduction of KLC1 in AD and AD-DS brains as compared with control brains. Studies comparing Dp16 to its euploid control recapitulated human studies in demonstrating no change in KIF5 levels and a positive correlation between the levels of KIF5 family members. J20 mice also showed normal KIF5 levels. However, unlike the AD and AD-DS frontal cortex, KLC1 levels were not reduced in the brains of Dp16 or J20 mice. CONCLUSION These data point to significant reductions in KLC1 in AD and AD-DS. In so doing, they raise the possibility of compromised KLC1-mediated axonal transport in these conditions, a posit that can now be pursued in model systems in which KLC1 expression is reduced.
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Affiliation(s)
- Xu-Qiao Chen
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California San Diego, La Jolla, CA 92093 USA
| | - Utpal Das
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California San Diego, La Jolla, CA 92093 USA
| | - Gooho Park
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California San Diego, La Jolla, CA 92093 USA
| | - William C. Mobley
- grid.266100.30000 0001 2107 4242Department of Neurosciences, University of California San Diego, La Jolla, CA 92093 USA
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Guo Y, Wang Q, Chen S, Xu C. Functions of amyloid precursor protein in metabolic diseases. Metabolism 2021; 115:154454. [PMID: 33248065 DOI: 10.1016/j.metabol.2020.154454] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/04/2020] [Revised: 11/02/2020] [Accepted: 11/23/2020] [Indexed: 02/07/2023]
Abstract
Amyloid precursor protein (APP) is a transmembrane precursor protein that is widely expressed in the central nervous system and peripheral tissues in the liver and pancreas, adipose tissue, and myotubes. APP can be cleaved by proteases in two different ways to produce a variety of short peptides, each with different physiological properties and functions. APP peptides generated by non-amyloidogenic processing can positively influence metabolism, while the peptides produced by amyloidogenic processing have the opposite effects. Here, we summarize the regulatory effects of APP and its cleavage peptides on metabolism in the central nervous system and peripheral tissues. In addition, abnormal expression and function of APP and APP-derived peptides are associated with metabolic diseases, such as type 2 diabetes, obesity, non-alcoholic fatty liver disease, and cardiovascular disease, and cancers. Pharmacological intervention of APP function or reduction of the production of peptides derived from amyloidogenic processing may be effective strategies for the prevention and treatment of Alzheimer's disease, and they may also provide new guidance for the treatment of metabolic diseases.
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Affiliation(s)
- Yanjun Guo
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Qinqiu Wang
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Shenghui Chen
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China
| | - Chengfu Xu
- Department of Gastroenterology, the First Affiliated Hospital, Zhejiang University School of Medicine, Hangzhou 310003, China.
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Huo Q, Tabassum S, Chen M, Sun M, Deng Y, Zheng X, Li Y, Chen J, Long C, Yang L. Amyloid-β Protein Precursor Deficiency Changes Neuronal Electrical Activity and Levels of Mitochondrial Proteins in the Medial Prefrontal Cortex. J Alzheimers Dis 2021; 81:1469-1482. [PMID: 33935084 DOI: 10.3233/jad-201557] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/15/2022]
Abstract
BACKGROUND Neuropathological features of Alzheimer's disease are characterized by the deposition of amyloid-β (Aβ) plaques and impairments in synaptic activity and memory. However, we know little about the physiological role of amyloid-β protein precursor (AβPP) from which Aβ derives. OBJECTIVE Evaluate APP deficiency induced alterations in neuronal electrical activity and mitochondrial protein expression. METHODS Utilizing electrophysiological, biochemical, pharmacological, and behavioral tests, we revealed aberrant local field potential (LFP), extracellular neuronal firing and levels of mitochondrial proteins. RESULT We show that APP knockout (APP-/-) leads to increased gamma oscillations in the medial prefrontal cortex (mPFC) at 1-2 months old, which can be restored by baclofen (Bac), a γ-aminobutyric acid type B receptor (GABABR) agonist. A higher dose and longer exposure time is required for Bac to suppress neuronal firing in APP-/- mice than in wild type animals, indicating enhanced GABABR mediated activity in the mPFC of APP-/- mice. In line with increased GABABR function, the glutamine synthetase inhibitor, L-methionine sulfonate, significantly increases GABABR levels in the mPFC of APP-/- mice and this is associated with a significantly lower incidence of death. The results suggest that APP-/- mice developed stronger GABABR mediated inhibition. Using HEK 293 as an expression system, we uncover that AβPP functions to suppress GABABR expression. Furthermore, APP-/- mice show abnormal expression of several mitochondrial proteins. CONCLUSION APP deficiency leads to both abnormal network activity involving defected GABABR and mitochondrial dysfunction, suggesting critical role of AβPP in synaptic and network function.
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Affiliation(s)
- Qingwei Huo
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
- Medical College of Acu-Moxi and Rehabilitation, Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Sidra Tabassum
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
| | - Ming Chen
- Department of Pharmacology, Key Laboratory of Anti-inflammatory and Immunopharmacology, School of Basic Medical Sciences, Anhui Medical University, Hefei, China
| | - Mengyao Sun
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yueming Deng
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Xingzhi Zheng
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Yi Li
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Jian Chen
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Cheng Long
- School of Life Sciences, South China Normal University, Guangzhou, China
| | - Li Yang
- Precise Genome Engineering Center, School of Life Sciences, Guangzhou University, Guangzhou, China
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Sohrabi M, Pecoraro HL, Combs CK. Gut Inflammation Induced by Dextran Sulfate Sodium Exacerbates Amyloid-β Plaque Deposition in the AppNL-G-F Mouse Model of Alzheimer's Disease. J Alzheimers Dis 2021; 79:1235-1255. [PMID: 33427741 PMCID: PMC8122495 DOI: 10.3233/jad-201099] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
BACKGROUND Although it is known that the brain communicates with the gastrointestinal (GI) tract via the well-established gut-brain axis, the influence exerted by chronic intestinal inflammation on brain changes in Alzheimer's disease (AD) is not fully understood. We hypothesized that increased gut inflammation would alter brain pathology of a mouse model of AD. OBJECTIVE Determine whether colitis exacerbates AD-related brain changes. METHODS To test this idea, 2% dextran sulfate sodium (DSS) was dissolved in the drinking water and fed ad libitum to male C57BL/6 wild type and AppNL-G-F mice at 6-10 months of age for two cycles of three days each. DSS is a negatively charged sulfated polysaccharide which results in bloody diarrhea and weight loss, changes similar to human inflammatory bowel disease (IBD). RESULTS Both wild type and AppNL-G-F mice developed an IBD-like condition. Brain histologic and biochemical assessments demonstrated increased insoluble Aβ1-40/42 levels along with the decreased microglial CD68 immunoreactivity in DSS treated AppNL-G-F mice compared to vehicle treated AppNL-G-F mice. CONCLUSION These data demonstrate that intestinal dysfunction is capable of altering plaque deposition and glial immunoreactivity in the brain. This study increases our knowledge of the impact of peripheral inflammation on Aβ deposition via an IBD-like model system.
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Affiliation(s)
- Mona Sohrabi
- Department of Biomedical Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND
| | - Heidi L. Pecoraro
- Veterinary Diagnostic Laboratory, North Dakota State University, Fargo ND
| | - Colin K. Combs
- Department of Biomedical Sciences, University of North Dakota School of Medicine & Health Sciences, Grand Forks, ND
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Tsatsanis A, McCorkindale AN, Wong BX, Patrick E, Ryan TM, Evans RW, Bush AI, Sutherland GT, Sivaprasadarao A, Guennewig B, Duce JA. The acute phase protein lactoferrin is a key feature of Alzheimer's disease and predictor of Aβ burden through induction of APP amyloidogenic processing. Mol Psychiatry 2021; 26:5516-5531. [PMID: 34400772 PMCID: PMC8758478 DOI: 10.1038/s41380-021-01248-1] [Citation(s) in RCA: 23] [Impact Index Per Article: 7.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/22/2021] [Revised: 07/17/2021] [Accepted: 07/23/2021] [Indexed: 02/06/2023]
Abstract
Amyloidogenic processing of the amyloid precursor protein (APP) forms the amyloid-β peptide (Aβ) component of pathognomonic extracellular plaques of AD. Additional early cortical changes in AD include neuroinflammation and elevated iron levels. Activation of the innate immune system in the brain is a neuroprotective response to infection; however, persistent neuroinflammation is linked to AD neuropathology by uncertain mechanisms. Non-parametric machine learning analysis on transcriptomic data from a large neuropathologically characterised patient cohort revealed the acute phase protein lactoferrin (Lf) as the key predictor of amyloid pathology. In vitro studies showed that an interaction between APP and the iron-bound form of Lf secreted from activated microglia diverted neuronal APP endocytosis from the canonical clathrin-dependent pathway to one requiring ADP ribosylation factor 6 trafficking. By rerouting APP recycling to the Rab11-positive compartment for amyloidogenic processing, Lf dramatically increased neuronal Aβ production. Lf emerges as a novel pharmacological target for AD that not only modulates APP processing but provides a link between Aβ production, neuroinflammation and iron dysregulation.
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Affiliation(s)
- Andrew Tsatsanis
- grid.5335.00000000121885934The ALBORADA Drug Discovery Institute, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK ,grid.9909.90000 0004 1936 8403Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, West Yorkshire UK
| | - Andrew N. McCorkindale
- grid.1013.30000 0004 1936 834XFaculty of Medicine and Health, Charles Perkins Centre and School of Medical Sciences, University of Sydney, Camperdown, NSW Australia
| | - Bruce X. Wong
- grid.5335.00000000121885934The ALBORADA Drug Discovery Institute, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK ,grid.9909.90000 0004 1936 8403Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, West Yorkshire UK ,grid.1008.90000 0001 2179 088XMelbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC Australia
| | - Ellis Patrick
- grid.1013.30000 0004 1936 834XFaculty of Science, School of Mathematics and Statistics, University of Sydney, Camperdown, NSW Australia
| | - Tim M. Ryan
- grid.1008.90000 0001 2179 088XMelbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC Australia
| | - Robert W. Evans
- grid.7728.a0000 0001 0724 6933School of Engineering and Design, Brunel University, London, UK
| | - Ashley I. Bush
- grid.1008.90000 0001 2179 088XMelbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC Australia
| | - Greg T. Sutherland
- grid.1013.30000 0004 1936 834XFaculty of Medicine and Health, Charles Perkins Centre and School of Medical Sciences, University of Sydney, Camperdown, NSW Australia
| | - Asipu Sivaprasadarao
- grid.9909.90000 0004 1936 8403Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, West Yorkshire UK
| | - Boris Guennewig
- grid.1013.30000 0004 1936 834XFaculty of Medicine and Health, Brain and Mind Centre and School of Medical Sciences, The University of Sydney, Camperdown, NSW Australia
| | - James A. Duce
- grid.5335.00000000121885934The ALBORADA Drug Discovery Institute, University of Cambridge, Cambridge Biomedical Campus, Cambridge, UK ,grid.9909.90000 0004 1936 8403Faculty of Biological Sciences, School of Biomedical Sciences, University of Leeds, Leeds, West Yorkshire UK ,grid.1008.90000 0001 2179 088XMelbourne Dementia Research Centre, The Florey Institute of Neuroscience and Mental Health, The University of Melbourne, Melbourne, VIC Australia
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Lee SH, Kang J, Ho A, Watanabe H, Bolshakov VY, Shen J. APP Family Regulates Neuronal Excitability and Synaptic Plasticity but Not Neuronal Survival. Neuron 2020; 108:676-690.e8. [PMID: 32891188 PMCID: PMC7704911 DOI: 10.1016/j.neuron.2020.08.011] [Citation(s) in RCA: 44] [Impact Index Per Article: 11.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2020] [Revised: 08/11/2020] [Accepted: 08/13/2020] [Indexed: 01/03/2023]
Abstract
Amyloid precursor protein (APP) is associated with both familial and sporadic forms of Alzheimer's disease. Despite its importance, the role of APP family in neuronal function and survival remains unclear because of perinatal lethality exhibited by knockout mice lacking all three APP family members. Here we report that selective inactivation of APP family members in excitatory neurons of the postnatal forebrain results in neither cortical neurodegeneration nor increases in apoptosis and gliosis up to ∼2 years of age. However, hippocampal synaptic plasticity, learning, and memory are impaired in these mutant mice. Furthermore, hippocampal neurons lacking APP family exhibit hyperexcitability, as evidenced by increased neuronal spiking in response to depolarizing current injections, whereas blockade of Kv7 channels mimics and largely occludes the effects of APP family inactivation. These findings demonstrate that APP family is not required for neuronal survival and suggest that APP family may regulate neuronal excitability through Kv7 channels.
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Affiliation(s)
- Sang Hun Lee
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Jongkyun Kang
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Angela Ho
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Hirotaka Watanabe
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA
| | - Vadim Y Bolshakov
- Department of Psychiatry, McLean Hospital, Harvard Medical School, Boston, MA 02115, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA
| | - Jie Shen
- Department of Neurology, Brigham and Women's Hospital, Harvard Medical School, Boston, MA 02115, USA; Program in Neuroscience, Harvard Medical School, Boston, MA 02115, USA.
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49
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Kesika P, Suganthy N, Sivamaruthi BS, Chaiyasut C. Role of gut-brain axis, gut microbial composition, and probiotic intervention in Alzheimer's disease. Life Sci 2020; 264:118627. [PMID: 33169684 DOI: 10.1016/j.lfs.2020.118627] [Citation(s) in RCA: 197] [Impact Index Per Article: 49.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/17/2020] [Revised: 10/05/2020] [Accepted: 10/12/2020] [Indexed: 02/06/2023]
Abstract
Gut microbiota represents a diverse and dynamic population of microorganisms harboring the gastrointestinal tract, which influences the host health and disease. Gut microbiota communicates with the brain and vice versa through complex bidirectional communication systems - the gut-brain axis, which integrates the peripheral intestinal function with emotional and cognitive brain centers via neuro-immuno-endocrine mediators. Aging alters the gut microbial population, which not only leads to gastrointestinal disturbances but also causes central nervous system (CNS) disorders such as dementia. Alzheimer's disease (AD) is the most common form of dementia affecting the older person, characterized by beta-amyloid (Aβ) plaques and neurofibrillary tangles leading to the cognitive deficit and memory impairment. Multiple experimental and clinical studies revealed the role of gut microbiota in host cognition, and its dysbiosis associated with aging leads to neurodegeneration. Gut microbial dysbiosis leads to the secretion of amyloid and lipopolysaccharides (LPS), which disturbs the gastrointestinal permeability and blood-brain barrier. Thereby modulates the inflammatory signaling pathway promoting neuroinflammation, neuronal injury, and ultimately leading to neuronal death in AD. A recent study revealed the antimicrobial property of Aβ peptide as an innate immune response against pathogenic microbes. Another study showed that bacterial amyloid shares molecular mimicry with Aβ peptide, which elicits misfolding and aggregation of Aβ peptide, it's seeding, and propagation through the gut-brain axis followed by microglial cell activation. As aging together with poor diet and gut-derived inflammatory response due to dysbiosis contributes to the pathogenesis of AD, modification of gut microbial composition by uptake of probiotic-rich food can act as a preventive/therapeutic option for AD. The objective of the present review is to summarize the recent findings on the role of gut microbiota in the development of AD. Understanding the relationship between gut microbiota and CNS will help identify novel therapeutic strategies, especially probiotic-based supplementation, for the treatment of AD.
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Affiliation(s)
- Periyanaina Kesika
- Innovation Center for Holistic Health, Nutraceuticals, and Cosmeceuticals, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Natarajan Suganthy
- Department of Nanoscience and Technology, Alagappa University, Karaikudi 630003, India
| | - Bhagavathi Sundaram Sivamaruthi
- Innovation Center for Holistic Health, Nutraceuticals, and Cosmeceuticals, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand
| | - Chaiyavat Chaiyasut
- Innovation Center for Holistic Health, Nutraceuticals, and Cosmeceuticals, Faculty of Pharmacy, Chiang Mai University, Chiang Mai 50200, Thailand.
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50
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Suire CN, Abdul-Hay SO, Sahara T, Kang D, Brizuela MK, Saftig P, Dickson DW, Rosenberry TL, Leissring MA. Cathepsin D regulates cerebral Aβ42/40 ratios via differential degradation of Aβ42 and Aβ40. ALZHEIMERS RESEARCH & THERAPY 2020; 12:80. [PMID: 32631408 PMCID: PMC7339583 DOI: 10.1186/s13195-020-00649-8] [Citation(s) in RCA: 28] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/06/2020] [Accepted: 06/24/2020] [Indexed: 11/10/2022]
Abstract
BACKGROUND Cathepsin D (CatD) is a lysosomal protease that degrades both the amyloid β-protein (Aβ) and the microtubule-associated protein, tau, and has been genetically linked to late-onset Alzheimer disease (AD). Here, we sought to examine the consequences of genetic deletion of CatD on Aβ proteostasis in vivo and to more completely characterize the degradation of Aβ42 and Aβ40 by CatD. METHODS We quantified Aβ degradation rates and levels of endogenous Aβ42 and Aβ40 in the brains of CatD-null (CatD-KO), heterozygous null (CatD-HET), and wild-type (WT) control mice. CatD-KO mice die by ~ 4 weeks of age, so tissues from younger mice, as well as embryonic neuronal cultures, were investigated. Enzymological assays and surface plasmon resonance were employed to quantify the kinetic parameters (KM, kcat) of CatD-mediated degradation of monomeric human Aβ42 vs. Aβ40, and the degradation of aggregated Aβ42 species was also characterized. Competitive inhibition assays were used to interrogate the relative inhibition of full-length human and mouse Aβ42 and Aβ40, as well as corresponding p3 fragments. RESULTS Genetic deletion of CatD resulted in 3- to 4-fold increases in insoluble, endogenous cerebral Aβ42 and Aβ40, exceeding the increases produced by deletion of an insulin-degrading enzyme, neprilysin or both, together with readily detectable intralysosomal deposits of endogenous Aβ42-all by 3 weeks of age. Quite significantly, CatD-KO mice exhibited ~ 30% increases in Aβ42/40 ratios, comparable to those induced by presenilin mutations. Mechanistically, the perturbed Aβ42/40 ratios were attributable to pronounced differences in the kinetics of degradation of Aβ42 vis-à-vis Aβ40. Specifically, Aβ42 shows a low-nanomolar affinity for CatD, along with an exceptionally slow turnover rate that, together, renders Aβ42 a highly potent competitive inhibitor of CatD. Notably, the marked differences in the processing of Aβ42 vs. Aβ40 also extend to p3 fragments ending at positions 42 vs. 40. CONCLUSIONS Our findings identify CatD as the principal intracellular Aβ-degrading protease identified to date, one that regulates Aβ42/40 ratios via differential degradation of Aβ42 vs. Aβ40. The finding that Aβ42 is a potent competitive inhibitor of CatD suggests a possible mechanistic link between elevations in Aβ42 and downstream pathological sequelae in AD.
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Affiliation(s)
- Caitlin N Suire
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, 92697, USA.,Department of Neurobiology and Behavior, University of California, Irvine, Irvine, CA, 92697, USA
| | - Samer O Abdul-Hay
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, 32224, USA
| | - Tomoko Sahara
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, 32224, USA
| | - Dongcheul Kang
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, 32224, USA
| | - Monica K Brizuela
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, 92697, USA
| | - Paul Saftig
- Institut für Biochemie, Christian-Albrechts-Universität zu Kiel, 24098, Kiel, Germany
| | - Dennis W Dickson
- Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, 32224, USA
| | | | - Malcolm A Leissring
- Institute for Memory Impairments and Neurological Disorders, University of California, Irvine, Irvine, CA, 92697, USA. .,Department of Neuroscience, Mayo Clinic Florida, Jacksonville, FL, 32224, USA.
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