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Delle C, Wang X, Giannetto M, Newbold E, Peng W, Gomolka RS, Ladrón-de-Guevara A, Cankar N, Schiøler Nielsen E, Kjaerby C, Weikop P, Mori Y, Nedergaard M. Transient but not chronic hyperglycemia accelerates ocular glymphatic transport. Fluids Barriers CNS 2024; 21:26. [PMID: 38475818 DOI: 10.1186/s12987-024-00524-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/17/2023] [Accepted: 02/20/2024] [Indexed: 03/14/2024] Open
Abstract
Glymphatic transport is vital for the physiological homeostasis of the retina and optic nerve. Pathological alterations of ocular glymphatic fluid transport and enlarged perivascular spaces have been described in glaucomatous mice. It remains to be established how diabetic retinopathy, which impairs vision in about 50% of diabetes patients, impacts ocular glymphatic fluid transport. Here, we examined ocular glymphatic transport in chronic hyperglycemic diabetic mice as well as in healthy mice experiencing a daily transient increase in blood glucose. Mice suffering from severe diabetes for two and four months, induced by streptozotocin, exhibited no alterations in ocular glymphatic fluid transport in the optic nerve compared to age-matched, non-diabetic controls. In contrast, transient increases in blood glucose induced by repeated daily glucose injections in healthy, awake, non-diabetic mice accelerated antero- and retrograde ocular glymphatic transport. Structural analysis showed enlarged perivascular spaces in the optic nerves of glucose-treated mice, which were absent in diabetic mice. Thus, transient repeated hyperglycemic events, but not constant hyperglycemia, ultimately enlarge perivascular spaces in the murine optic nerve. These findings indicate that fluid transport in the mouse eye is vulnerable to fluctuating glycemic levels rather than constant hyperglycemia, suggesting that poor glycemic control drives glymphatic malfunction and perivascular enlargement in the optic nerve.
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Affiliation(s)
- Christine Delle
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Xiaowei Wang
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, 14642, Rochester, NY, USA
- School of Medicine, University of California, San Francisco, 10 Koret Way, 94117, San Francisco, CA, USA
| | - Michael Giannetto
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, 14642, Rochester, NY, USA
| | - Evan Newbold
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, 14642, Rochester, NY, USA
| | - Weiguo Peng
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, 14642, Rochester, NY, USA
| | - Ryszard Stefan Gomolka
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Antonio Ladrón-de-Guevara
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, 14642, Rochester, NY, USA
| | - Neža Cankar
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Elise Schiøler Nielsen
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Celia Kjaerby
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Pia Weikop
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Yuki Mori
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark
| | - Maiken Nedergaard
- Center for Translational Neuromedicine, Faculty of Medical and Health Sciences, University of Copenhagen, Blegdamsvej 3B, 2200, Copenhagen N, Denmark.
- Center for Translational Neuromedicine, University of Rochester Medical School, Elmwood Avenue 601, 14642, Rochester, NY, USA.
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Conn KA, Borsom EM, Cope EK. Implications of microbe-derived ɣ-aminobutyric acid (GABA) in gut and brain barrier integrity and GABAergic signaling in Alzheimer's disease. Gut Microbes 2024; 16:2371950. [PMID: 39008552 PMCID: PMC11253888 DOI: 10.1080/19490976.2024.2371950] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 03/13/2024] [Accepted: 06/19/2024] [Indexed: 07/17/2024] Open
Abstract
The gut microbial ecosystem communicates bidirectionally with the brain in what is known as the gut-microbiome-brain axis. Bidirectional signaling occurs through several pathways including signaling via the vagus nerve, circulation of microbial metabolites, and immune activation. Alterations in the gut microbiota are implicated in Alzheimer's disease (AD), a progressive neurodegenerative disease. Perturbations in gut microbial communities may affect pathways within the gut-microbiome-brain axis through altered production of microbial metabolites including ɣ-aminobutyric acid (GABA), the primary inhibitory mammalian neurotransmitter. GABA has been shown to act on gut integrity through modulation of gut mucins and tight junction proteins and may be involved in vagus nerve signal inhibition. The GABAergic signaling pathway has been shown to be dysregulated in AD, and may be responsive to interventions. Gut microbial production of GABA is of recent interest in neurological disorders, including AD. Bacteroides and Lactic Acid Bacteria (LAB), including Lactobacillus, are predominant producers of GABA. This review highlights how temporal alterations in gut microbial communities associated with AD may affect the GABAergic signaling pathway, intestinal barrier integrity, and AD-associated inflammation.
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Affiliation(s)
- Kathryn A. Conn
- Center for Applied Microbiome Sciences, The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
| | - Emily M. Borsom
- Center for Data-Driven Discovery for Biology, Allen Institute, Seattle, WA, USA
| | - Emily K. Cope
- Center for Applied Microbiome Sciences, The Pathogen and Microbiome Institute, Northern Arizona University, Flagstaff, AZ, USA
- Department of Biological Sciences, Northern Arizona University, Flagstaff, AZ, USA
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3
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Swinford CG, Risacher SL, Vosmeier A, Deardorff R, Chumin EJ, Dzemidzic M, Wu YC, Gao S, McDonald BC, Yoder KK, Unverzagt FW, Wang S, Farlow MR, Brosch JR, Clark DG, Apostolova LG, Sims J, Wang DJ, Saykin AJ. Amyloid and tau pathology are associated with cerebral blood flow in a mixed sample of nondemented older adults with and without vascular risk factors for Alzheimer's disease. Neurobiol Aging 2023; 130:103-113. [PMID: 37499587 PMCID: PMC10529454 DOI: 10.1016/j.neurobiolaging.2023.06.014] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2022] [Revised: 05/30/2023] [Accepted: 06/21/2023] [Indexed: 07/29/2023]
Abstract
Identification of biomarkers for the early stages of Alzheimer's disease (AD) is an imperative step in developing effective treatments. Cerebral blood flow (CBF) is a potential early biomarker for AD; generally, older adults with AD have decreased CBF compared to normally aging peers. CBF deviates as the disease process and symptoms progress. However, further characterization of the relationships between CBF and AD risk factors and pathologies is still needed. We assessed the relationships between CBF quantified by arterial spin-labeled magnetic resonance imaging, hypertension, APOEε4, and tau and amyloid positron emission tomography in 77 older adults: cognitively normal, subjective cognitive decline, and mild cognitive impairment. Tau and amyloid aggregation were related to altered CBF, and some of these relationships were dependent on hypertension or APOEε4 status. Our findings suggest a complex relationship between risk factors, AD pathologies, and CBF that warrants future studies of CBF as a potential early biomarker for AD.
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Affiliation(s)
- Cecily G Swinford
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Shannon L Risacher
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Aaron Vosmeier
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Rachael Deardorff
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Evgeny J Chumin
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Indiana University Network Science Institute, Bloomington, IN, USA; Department of Psychological and Brain Sciences, Indiana University, Bloomington, IN, USA
| | - Mario Dzemidzic
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Yu-Chien Wu
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Sujuan Gao
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Biostatistics and Health Data Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Brenna C McDonald
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Karmen K Yoder
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA
| | - Frederick W Unverzagt
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Sophia Wang
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Psychiatry, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Martin R Farlow
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Jared R Brosch
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - David G Clark
- Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Liana G Apostolova
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana University Network Science Institute, Bloomington, IN, USA
| | - Justin Sims
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Danny J Wang
- Stevens Neuroimaging and Informatics Institute, Keck School of Medicine, University of Southern California, Los Angeles, CA, USA
| | - Andrew J Saykin
- Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana Alzheimer's Disease Research Center, Indianapolis, IN, USA; Department of Neurology, Indiana University School of Medicine, Indianapolis, IN, USA; Indiana University Network Science Institute, Bloomington, IN, USA.
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4
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Khare P, Edgecomb SX, Hamadani CM, E L Tanner E, Manickam DS. Lipid nanoparticle-mediated drug delivery to the brain. Adv Drug Deliv Rev 2023; 197:114861. [PMID: 37150326 DOI: 10.1016/j.addr.2023.114861] [Citation(s) in RCA: 12] [Impact Index Per Article: 12.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2023] [Revised: 04/12/2023] [Accepted: 05/02/2023] [Indexed: 05/09/2023]
Abstract
Lipid nanoparticles (LNPs) have revolutionized the field of drug delivery through their applications in siRNA delivery to the liver (Onpattro) and their use in the Pfizer-BioNTech and Moderna COVID-19 mRNA vaccines. While LNPs have been extensively studied for the delivery of RNA drugs to muscle and liver targets, their potential to deliver drugs to challenging tissue targets such as the brain remains underexplored. Multiple brain disorders currently lack safe and effective therapies and therefore repurposing LNPs could potentially be a game changer for improving drug delivery to cellular targets both at and across the blood-brain barrier (BBB). In this review, we will discuss (1) the rationale and factors involved in optimizing LNPs for brain delivery, (2) ionic liquid-coated LNPs as a potential approach for increasing LNP accumulation in the brain tissue and (3) considerations, open questions and potential opportunities in the development of LNPs for delivery to the brain.
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Affiliation(s)
- Purva Khare
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA
| | - Sara X Edgecomb
- Department of Chemistry and Biochemistry, The University of Mississippi, MS
| | | | - Eden E L Tanner
- Department of Chemistry and Biochemistry, The University of Mississippi, MS.
| | - Devika S Manickam
- Graduate School of Pharmaceutical Sciences, Duquesne University, Pittsburgh, PA.
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Sapkota S, Erickson K, Fletcher E, Tomaszewski Farias SE, Jin LW, DeCarli C. Vascular Risk Predicts Plasma Amyloid β 42/40 Through Cerebral Amyloid Burden in Apolipoprotein E ε4 Carriers. Stroke 2023; 54:1227-1235. [PMID: 37021572 PMCID: PMC10121244 DOI: 10.1161/strokeaha.122.041854] [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: 11/02/2022] [Revised: 02/28/2023] [Accepted: 03/08/2023] [Indexed: 04/07/2023]
Abstract
BACKGROUND Understanding the neurobiological underpinnings between established multimodal dementia risk factors and noninvasive blood-based biomarkers may lead to greater precision and earlier identification of older adults at risk of accelerated decline and dementia. We examined whether key vascular and genetic risk impact the association between cerebral amyloid burden and plasma aβ (amyloid β) 42/40 in nondemented older adults. METHODS We used nondemented older adults from the UCD-ADRC (University of California, Davis-Alzheimer's Disease Research Center) study (n=96) and Alzheimer's Disease Neuroimaging Initiative (n=104). Alzheimer's Disease Neuroimaging Initiative was examined as confirmatory study cohort. We followed a cross-sectional design and examined linear regression followed by mediation analyses. Vascular risk score was obtained as the sum of hypertension, diabetes, hyperlipidemia, coronary artery disease, and cerebrovascular disease. Apolipoprotein E (APOE) ε4+ risk was genotyped, and plasma aβ42 and aβ40 were assayed. Cerebral amyloid burden was quantified using Florbetapir-PET scans. Baseline age was included as a covariate in all models. RESULTS Vascular risk significantly predicted cerebral amyloid burden in Alzheimer's Disease Neuroimaging Initiative but not in the UCD-ADRC cohort. Cerebral amyloid burden was associated with plasma aβ 42/40 in both cohorts. Higher vascular risk increased cerebral amyloid burden was indirectly associated with reduced plasma aβ 42/40 in Alzheimer's Disease Neuroimaging Initiative but not in UCD-ADRC cohort. However, when stratified by APOE ε4+ risk, we consistently observed this indirect relationship only in APOE ε4+ carriers across both cohorts. CONCLUSIONS Vascular risk is indirectly associated with the level of plasma aβ 42/40 via cerebral amyloid burden only in APOE ε4+ carriers. Nondemented older adults with genetic vulnerability to dementia and accelerated decline may benefit from careful monitoring of vascular risk factors directly associated with cerebral amyloid burden and indirectly with plasma aβ 42/40.
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Affiliation(s)
- Shraddha Sapkota
- Department of Neurology (S.S., E.F., S.E.T.F., C.D.), University of California, Davis
| | - Kelsey Erickson
- Department of Neurology (S.S., E.F., S.E.T.F., C.D.), University of California, Davis
| | - Evan Fletcher
- University of California, and Department of Pathology and Laboratory Medicine (K.E., L.-W.J.), University of California, Davis
| | | | - Lee-Way Jin
- University of California, and Department of Pathology and Laboratory Medicine (K.E., L.-W.J.), University of California, Davis
| | - Charles DeCarli
- Department of Neurology (S.S., E.F., S.E.T.F., C.D.), University of California, Davis
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6
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Chun MY, Jang H, Kim HJ, Kim JP, Gallacher J, Allué JA, Sarasa L, Castillo S, Pascual-Lucas M, Na DL, Seo SW. Contribution of clinical information to the predictive performance of plasma β-amyloid levels for amyloid positron emission tomography positivity. Front Aging Neurosci 2023; 15:1126799. [PMID: 36998318 PMCID: PMC10044013 DOI: 10.3389/fnagi.2023.1126799] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2022] [Accepted: 02/24/2023] [Indexed: 03/15/2023] Open
Abstract
BackgroundEarly detection of β-amyloid (Aβ) accumulation, a major biomarker for Alzheimer’s disease (AD), has become important. As fluid biomarkers, the accuracy of cerebrospinal fluid (CSF) Aβ for predicting Aβ deposition on positron emission tomography (PET) has been extensively studied, and the development of plasma Aβ is beginning to receive increased attention recently. In the present study, we aimed to determine whether APOE genotypes, age, and cognitive status increase the predictive performance of plasma Aβ and CSF Aβ levels for Aβ PET positivity.MethodsWe recruited 488 participants who underwent both plasma Aβ and Aβ PET studies (Cohort 1) and 217 participants who underwent both cerebrospinal fluid (CSF) Aβ and Aβ PET studies (Cohort 2). Plasma and CSF samples were analyzed using ABtest-MS, an antibody-free liquid chromatography-differential mobility spectrometry-triple quadrupole mass spectrometry method and INNOTEST enzyme-linked immunosorbent assay kits, respectively. To evaluate the predictive performance of plasma Aβ and CSF Aβ, respectively, logistic regression and receiver operating characteristic analyses were performed.ResultsWhen predicting Aβ PET status, both plasma Aβ42/40 ratio and CSF Aβ42 showed high accuracy (plasma Aβ area under the curve (AUC) 0.814; CSF Aβ AUC 0.848). In the plasma Aβ models, the AUC values were higher than plasma Aβ alone model, when the models were combined with either cognitive stage (p < 0.001) or APOE genotype (p = 0.011). On the other hand, there was no difference between the CSF Aβ models, when these variables were added.ConclusionPlasma Aβ might be a useful predictor of Aβ deposition on PET status as much as CSF Aβ, particularly when considered with clinical information such as APOE genotype and cognitive stage.
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Affiliation(s)
- Min Young Chun
- Departments of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Department of Neurology, Yonsei University College of Medicine, Seoul, Republic of Korea
- Department of Neurology, Yongin Severance Hospital, Yonsei University Health System, Yongin, Republic of Korea
| | - Hyemin Jang
- Departments of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Neuroscience Center, Samsung Medical Center, Seoul, Republic of Korea
- Alzheimer's Disease Convergence Research Center, Samsung Medical Center, Seoul, Republic of Korea
- *Correspondence: Hyemin Jang, ; Sang Won Seo,
| | - Hee Jin Kim
- Departments of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Alzheimer's Disease Convergence Research Center, Samsung Medical Center, Seoul, Republic of Korea
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
- Department of Digital Health, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
| | - Jun Pyo Kim
- Departments of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Center for Neuroimaging, Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, United States
| | - John Gallacher
- Department of Psychiatry, Warneford Hospital, University of Oxford, Oxford, United Kingdom
| | | | | | | | | | - Duk L. Na
- Departments of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Alzheimer's Disease Convergence Research Center, Samsung Medical Center, Seoul, Republic of Korea
| | - Sang Won Seo
- Departments of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea
- Alzheimer's Disease Convergence Research Center, Samsung Medical Center, Seoul, Republic of Korea
- Department of Health Sciences and Technology, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
- Department of Digital Health, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
- Department of Clinical Research Design and Evaluation, SAIHST, Sungkyunkwan University, Seoul, Republic of Korea
- *Correspondence: Hyemin Jang, ; Sang Won Seo,
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7
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Marsland P, Vore AS, DaPrano E, Paluch JM, Blackwell AA, Varlinskaya EI, Deak T. Sex-specific effects of ethanol consumption in older Fischer 344 rats on microglial dynamics and Aβ (1-42) accumulation. Alcohol 2023; 107:108-118. [PMID: 36155778 DOI: 10.1016/j.alcohol.2022.08.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2022] [Revised: 08/23/2022] [Accepted: 08/23/2022] [Indexed: 11/15/2022]
Abstract
Chronic alcohol consumption, Alzheimer's disease (AD), and vascular dementia are all associated with cognitive decline later in life, raising questions about whether their underlying neuropathology may share some common features. Indeed, recent evidence suggests that ethanol exposure during adolescence or intermittent drinking in young adulthood increased neuropathological markers of AD, including both tau phosphorylation and beta-amyloid (Aβ) accumulation. The goal of the present study was to determine whether alcohol consumption later in life, a time when microglia and other neuroimmune processes tend to become overactive, would influence microglial clearance of Aβ(1-42), focusing specifically on microglia in close proximity to the neurovasculature. To do this, male and female Fischer 344 rats were exposed to a combination of voluntary and involuntary ethanol consumption from ∼10 months of age through ∼14 months of age. Immunofluorescence revealed profound sex differences in microglial co-localization, with Aβ(1-42) showing that aged female rats with a history of ethanol consumption had a higher number of iba1+ cells and marginally reduced expression of Aβ(1-42), suggesting greater phagocytic activity of Aβ(1-42) among females after chronic ethanol consumption later in life. Interestingly, these effects were most prominent in Iba1+ cells near neurovasculature that was stained with tomato lectin. In contrast, no significant effects of ethanol consumption were observed on any markers in males. These findings are among the first reports of a sex-specific increase in microglia-mediated phagocytosis of Aβ(1-42) by perivascular microglia in aged, ethanol-consuming rats, and may have important implications for understanding mechanisms of cognitive decline associated with chronic drinking.
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Affiliation(s)
- Paige Marsland
- Behavioral Neuroscience Program, Department of Psychology, Binghamton University, Binghamton, NY 13902-6000, United States
| | - Andrew S Vore
- Behavioral Neuroscience Program, Department of Psychology, Binghamton University, Binghamton, NY 13902-6000, United States
| | - Evan DaPrano
- Behavioral Neuroscience Program, Department of Psychology, Binghamton University, Binghamton, NY 13902-6000, United States
| | - Joanna M Paluch
- Behavioral Neuroscience Program, Department of Psychology, Binghamton University, Binghamton, NY 13902-6000, United States
| | - Ashley A Blackwell
- Behavioral Neuroscience Program, Department of Psychology, Binghamton University, Binghamton, NY 13902-6000, United States
| | - Elena I Varlinskaya
- Behavioral Neuroscience Program, Department of Psychology, Binghamton University, Binghamton, NY 13902-6000, United States
| | - Terrence Deak
- Behavioral Neuroscience Program, Department of Psychology, Binghamton University, Binghamton, NY 13902-6000, United States.
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Gouveia F, Camins A, Ettcheto M, Bicker J, Falcão A, Cruz MT, Fortuna A. Targeting brain Renin-Angiotensin System for the prevention and treatment of Alzheimer's disease: Past, present and future. Ageing Res Rev 2022; 77:101612. [PMID: 35346852 DOI: 10.1016/j.arr.2022.101612] [Citation(s) in RCA: 23] [Impact Index Per Article: 11.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/03/2021] [Revised: 02/09/2022] [Accepted: 03/16/2022] [Indexed: 12/12/2022]
Abstract
Alzheimer's disease (AD) is a well-known neurodegenerative disease characterized by the presence of two main hallmarks - Tau hyperphosphorylation and Aβ deposits. Notwithstanding, in the last few years the scientific evidence about the drivers of AD have been changing and nowadays age-related vascular alterations and several cardiovascular risk factors have been shown to trigger the development of AD. In this context, drugs targeting the Renin Angiotensin System (RAS), commonly used for the treatment of hypertension, are evidencing a high potential to delay AD development due to their action on brain RAS. Indeed, the ACE 1/Ang II/AT1R axis is believed to be upregulated in AD and to be responsible for deleterious effects such as increased oxidative stress, neuroinflammation, blood-brain barrier (BBB) hyperpermeability, astrocytes dysfunction and a decrease in cerebral blood flow. In contrast, the alternative axis - ACE 1/Ang II/AT2R; ACE 2/Ang (1-7)/MasR; Ang IV/ AT4R(IRAP) - seems to counterbalance the deleterious effects of the principal axis and to exert beneficial effects on memory and cognition. Accordingly, retrospective studies demonstrate a reduced risk of developing AD among people taking RAS medication as well as several in vitro and in vivo pre-clinical studies as it is herein critically reviewed. In this review, we first revise, at a glance, the pathophysiology of AD focused on its classic hallmarks. Secondly, an overview about the impact of the RAS on the pathophysiology of AD is also provided, focused on their four essential axes ACE 1/Ang II/AT2R; ACE 2/Ang (1-7)/MasR; Ang IV/ AT4R(IRAP) and ACE 1/Ang II/AT1R. Finally, the therapeutic potential of available drugs targeting RAS on AD, namely angiotensin II receptor blockers (ARBs) and angiotensin converting enzyme inhibitors (ACEIs), is highlighted and data supporting this hope will be presented, from in vitro and in vivo pre-clinical to clinical studies.
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9
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Jang H, Kim JS, Lee HJ, Kim CH, Na DL, Kim HJ, Allué JA, Sarasa L, Castillo S, Pesini P, Gallacher J, Seo SW. Performance of the plasma Aβ42/Aβ40 ratio, measured with a novel HPLC-MS/MS method, as a biomarker of amyloid PET status in a DPUK-KOREAN cohort. ALZHEIMERS RESEARCH & THERAPY 2021; 13:179. [PMID: 34686209 PMCID: PMC8540152 DOI: 10.1186/s13195-021-00911-7] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 04/07/2021] [Accepted: 10/02/2021] [Indexed: 12/20/2022]
Abstract
Background We assessed the feasibility of plasma Aβ42/Aβ40 determined using a novel liquid chromatography-mass spectrometry method (LC-MS) as a useful biomarker of PET status in a Korean cohort from the DPUK Study. Methods A total of 580 participants belonging to six groups, Alzheimer’s disease dementia (ADD, n = 134), amnestic mild cognitive impairment (aMCI, n = 212), old controls (OC, n = 149), young controls (YC, n = 15), subcortical vascular cognitive impairment (SVCI, n = 58), and cerebral amyloid angiopathy (CAA, n = 12), were included in this study. Plasma Aβ40 and Aβ42 were quantitated using a new antibody-free, LC-MS, which drastically reduced the sample preparation time and cost. We performed receiver operating characteristic (ROC) analysis to develop the cutoff of Aβ42/Aβ40 and investigated its performance predicting centiloid-based PET positivity (PET+). Results Plasma Aβ42/Aβ40 were lower for PET+ individuals in ADD, aMCI, OC, and SVCI (p < 0.001), but not in CAA (p = 0.133). In the group of YC, OC, aMCI, and ADD groups, plasma Aβ42/Aβ40 predicted PET+ with an area under the ROC curve (AUC) of 0.814 at a cutoff of 0.2576. When adding age, APOE4, and diagnosis, the AUC significantly improved to 0.912. Conclusion Plasma Aβ42/Aβ40, as measured by this novel LC-MS method, showed good discriminating performance based on PET positivity. Supplementary Information The online version contains supplementary material available at 10.1186/s13195-021-00911-7.
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Affiliation(s)
- Hyemin Jang
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Neuroscience Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Alzheimer's Disease Convergence Research Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea
| | - Ji Sun Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Neuroscience Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea
| | - Hye Joo Lee
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Alzheimer's Disease Convergence Research Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea
| | - Chi-Hun Kim
- Department of Neurology, School of Medicine, Kyungpook National University, Kyungpook National University Chilgok Hospital, Daegu, South Korea.,Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK
| | - Duk L Na
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Neuroscience Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Alzheimer's Disease Convergence Research Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Stem Cell & Regenerative Medicine Institute, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Department of Health Sciences and Technology, Seoul, Republic of Korea
| | - Hee Jin Kim
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Neuroscience Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea.,Alzheimer's Disease Convergence Research Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea
| | | | - Leticia Sarasa
- Araclon Biotech-Grifols, Vía Hispanidad, 21, 50009, Zaragoza, Spain
| | - Sergio Castillo
- Araclon Biotech-Grifols, Vía Hispanidad, 21, 50009, Zaragoza, Spain
| | - Pedro Pesini
- Araclon Biotech-Grifols, Vía Hispanidad, 21, 50009, Zaragoza, Spain
| | - John Gallacher
- Department of Psychiatry, University of Oxford, Warneford Hospital, Oxford, UK
| | - Sang Won Seo
- Department of Neurology, Samsung Medical Center, Sungkyunkwan University School of Medicine, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea. .,Neuroscience Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea. .,Alzheimer's Disease Convergence Research Center, Samsung Medical Center, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea. .,Department of Clinical Research Design & Evaluation, SAIHST, Sungkyunkwan University, 81 Irwon-ro, Gangnam-gu, Seoul, 06351, Republic of Korea. .,Department of Intelligent Precision Healthcare Convergence, Sungkyunkwan University School of Medicine, Seoul, Republic of Korea.
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10
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Ojo JO, Reed JM, Crynen G, Vallabhaneni P, Evans J, Shackleton B, Eisenbaum M, Ringland C, Edsell A, Mullan M, Crawford F, Bachmeier C. APOE genotype dependent molecular abnormalities in the cerebrovasculature of Alzheimer's disease and age-matched non-demented brains. Mol Brain 2021; 14:110. [PMID: 34238312 PMCID: PMC8268468 DOI: 10.1186/s13041-021-00803-9] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/27/2021] [Accepted: 06/04/2021] [Indexed: 12/14/2022] Open
Abstract
Cerebrovascular dysfunction is a hallmark feature of Alzheimer's disease (AD). One of the greatest risk factors for AD is the apolipoprotein E4 (E4) allele. The APOE4 genotype has been shown to negatively impact vascular amyloid clearance, however, its direct influence on the molecular integrity of the cerebrovasculature compared to other APOE variants (APOE2 and APOE3) has been largely unexplored. To address this, we employed a 10-plex tandem isobaric mass tag approach in combination with an ultra-high pressure liquid chromatography MS/MS (Q-Exactive) method, to interrogate unbiased proteomic changes in cerebrovessels from AD and healthy control brains with different APOE genotypes. We first interrogated changes between healthy control cases to identify underlying genotype specific effects in cerebrovessels. EIF2 signaling, regulation of eIF4 and 70S6K signaling and mTOR signaling were the top significantly altered pathways in E4/E4 compared to E3/E3 cases. Oxidative phosphorylation, EIF2 signaling and mitochondrial dysfunction were the top significant pathways in E2E2 vs E3/E3cases. We also identified AD-dependent changes and their interactions with APOE genotype and found the highest number of significant proteins from this interaction was observed in the E3/E4 (192) and E4/E4 (189) cases. As above, EIF2, mTOR signaling and eIF4 and 70S6K signaling were the top three significantly altered pathways in E4 allele carriers (i.e. E3/E4 and E4/E4 genotypes). Of all the cerebrovascular cell-type specific markers identified in our proteomic analyses, endothelial cell, astrocyte, and smooth muscle cell specific protein markers were significantly altered in E3/E4 cases, while endothelial cells and astrocyte specific protein markers were altered in E4/E4 cases. These proteomic changes provide novel insights into the longstanding link between APOE4 and cerebrovascular dysfunction, implicating a role for impaired autophagy, ER stress, and mitochondrial bioenergetics. These APOE4 dependent changes we identified could provide novel cerebrovascular targets for developing disease modifying strategies to mitigate the effects of APOE4 genotype on AD pathogenesis.
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Affiliation(s)
- Joseph O Ojo
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA. .,James A. Haley Veterans' Hospital, Tampa, FL, USA. .,The Open University, Milton Keynes, UK.
| | - Jon M Reed
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA.,Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT, USA
| | - Gogce Crynen
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA
| | | | - James Evans
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA
| | - Benjamin Shackleton
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK
| | - Maximillian Eisenbaum
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK
| | - Charis Ringland
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK
| | - Anastasia Edsell
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA
| | - Michael Mullan
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK
| | - Fiona Crawford
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA.,James A. Haley Veterans' Hospital, Tampa, FL, USA.,The Open University, Milton Keynes, UK
| | - Corbin Bachmeier
- Department of Experimental Neuropathology, Roskamp Institute, Sarasota, FL, 34243, USA.,The Open University, Milton Keynes, UK.,Bay Pines VA Healthcare System, Bay Pines, FL, USA
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11
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Ojo JO, Reed JM, Crynen G, Vallabhaneni P, Evans J, Shackleton B, Eisenbaum M, Ringland C, Edsell A, Mullan M, Crawford F, Bachmeier C. Molecular Pathobiology of the Cerebrovasculature in Aging and in Alzheimers Disease Cases With Cerebral Amyloid Angiopathy. Front Aging Neurosci 2021; 13:658605. [PMID: 34079449 PMCID: PMC8166206 DOI: 10.3389/fnagi.2021.658605] [Citation(s) in RCA: 10] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2021] [Accepted: 03/10/2021] [Indexed: 12/12/2022] Open
Abstract
Cerebrovascular dysfunction and cerebral amyloid angiopathy (CAA) are hallmark features of Alzheimer's disease (AD). Molecular damage to cerebrovessels in AD may result in alterations in vascular clearance mechanisms leading to amyloid deposition around blood vessels and diminished neurovascular-coupling. The sequelae of molecular events leading to these early pathogenic changes remains elusive. To address this, we conducted a comprehensive in-depth molecular characterization of the proteomic changes in enriched cerebrovessel fractions isolated from the inferior frontal gyrus of autopsy AD cases with low (85.5 ± 2.9 yrs) vs. high (81 ± 4.4 yrs) CAA score, aged-matched control (87.4 ± 1.5 yrs) and young healthy control (47 ± 3.3 yrs) cases. We employed a 10-plex tandem isobaric mass tag approach in combination with our ultra-high pressure liquid chromatography MS/MS (Q-Exactive) method. Enriched cerebrovascular fractions showed very high expression levels of proteins specific to endothelial cells, mural cells (pericytes and smooth muscle cells), and astrocytes. We observed 150 significantly regulated proteins in young vs. aged control cerebrovessels. The top pathways significantly modulated with aging included chemokine, reelin, HIF1α and synaptogenesis signaling pathways. There were 213 proteins significantly regulated in aged-matched control vs. high CAA cerebrovessels. The top three pathways significantly altered from this comparison were oxidative phosphorylation, Sirtuin signaling pathway and TCA cycle II. Comparison between low vs. high CAA cerebrovessels identified 84 significantly regulated proteins. Top three pathways significantly altered between low vs. high CAA cerebrovessels included TCA Cycle II, Oxidative phosphorylation and mitochondrial dysfunction. Notably, high CAA cases included more advanced AD pathology thus cerebrovascular effects may be driven by the severity of amyloid and Tangle pathology. These descriptive proteomic changes provide novel insights to explain the age-related and AD-related cerebrovascular changes contributing to AD pathogenesis. Particularly, disturbances in energy bioenergetics and mitochondrial biology rank among the top AD pathways altered in cerebrovessels. Targeting these failed mechanisms in endothelia and mural cells may provide novel disease modifying targets for developing therapeutic strategies against cerebrovascular deterioration and promoting cerebral perfusion in AD. Our future work will focus on interrogating and validating these novel targets and pathways and their functional significance.
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Affiliation(s)
- Joseph O. Ojo
- Roskamp Institute, Sarasota, FL, United States
- James A. Haley Veterans' Hospital, Tampa, FL, United States
- The Open University, Milton Keynes, United Kingdom
| | - Jon M. Reed
- Roskamp Institute, Sarasota, FL, United States
- Boehringer Ingelheim Pharmaceuticals, Inc., Ridgefield, CT, United States
| | | | | | - James Evans
- Roskamp Institute, Sarasota, FL, United States
| | - Benjamin Shackleton
- Roskamp Institute, Sarasota, FL, United States
- The Open University, Milton Keynes, United Kingdom
| | - Maximillian Eisenbaum
- Roskamp Institute, Sarasota, FL, United States
- The Open University, Milton Keynes, United Kingdom
| | - Charis Ringland
- Roskamp Institute, Sarasota, FL, United States
- The Open University, Milton Keynes, United Kingdom
| | | | - Michael Mullan
- Roskamp Institute, Sarasota, FL, United States
- The Open University, Milton Keynes, United Kingdom
| | - Fiona Crawford
- Roskamp Institute, Sarasota, FL, United States
- James A. Haley Veterans' Hospital, Tampa, FL, United States
- The Open University, Milton Keynes, United Kingdom
| | - Corbin Bachmeier
- Roskamp Institute, Sarasota, FL, United States
- The Open University, Milton Keynes, United Kingdom
- Bay Pines VA Healthcare System, Bay Pines, FL, United States
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12
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Emrani S, Lamar M, Price CC, Wasserman V, Matusz E, Au R, Swenson R, Nagele R, Heilman KM, Libon DJ. Alzheimer's/Vascular Spectrum Dementia: Classification in Addition to Diagnosis. J Alzheimers Dis 2021; 73:63-71. [PMID: 31815693 DOI: 10.3233/jad-190654] [Citation(s) in RCA: 44] [Impact Index Per Article: 14.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/01/2023]
Abstract
Alzheimer's disease (AD) and vascular dementia (VaD) are the two most common types of dementia. Although the combination of these disorders, called 'mixed' dementia, is recognized, the prevailing clinical and research perspective continues to consider AD and VaD as independent disorders. A review of recent neuropathological and neuropsychological literature reveals that these two disorders frequently co-occur and so-called 'pure' AD or VaD is comparatively rare. In addition, recent research shows that vascular dysfunction not only potentiates AD pathology, but that pathological changes in AD may subsequently induce vascular disorders. On the basis of these data, we propose that the neurobiological underpinnings underlying AD/VaD dementia and their neuropsychological phenotypes are best understood as existing along a clinical/pathological continuum or spectrum. We further propose that in conjunction with current diagnostic criteria, statistical modeling techniques using neuropsychological test performance should be leveraged to construct a system to classify AD/VaD spectrum dementia in order to test hypotheses regarding how mechanisms related to AD and VaD pathology interact and influence each other.
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Affiliation(s)
- Sheina Emrani
- Department of Psychology, Rowan University, Glassboro, NJ, USA
| | - Melissa Lamar
- Department of Behavioral Sciences and the Rush Alzheimer's Disease Center, Rush University Medical Center, Chicago, IL, USA
| | - Catherine C Price
- Department of Clinical and Health Psychology, University of Florida, Gainesville, FL, USA
| | | | - Emily Matusz
- New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Glassboro, NJ, USA
| | - Rhoda Au
- Department of Anatomy and Neurobiology, Neurology, Epidemiology, Boston University Schools of Medicine & Public Health, Boston, MA, USA
| | - Rodney Swenson
- Clinical Professor in the Department of Psychiatry and Behavioral Science at the University of North Dakota School of Medicine and Health Sciences, Grand Forks, ND, USA
| | - Robert Nagele
- New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Glassboro, NJ, USA
| | - Kenneth M Heilman
- Department of Neurology, Brain Rehabilitation Research Center, Malcom Randall VA Medical Center, Center for Cognitive Aging and Memory - Clinical Translational Research Program, and Center for Neuropsychological Studies, University of Florida, Gainseville, FL, USA
| | - David J Libon
- Department of Psychology, Rowan University, Glassboro, NJ, USA.,New Jersey Institute for Successful Aging, School of Osteopathic Medicine, Rowan University, Glassboro, NJ, USA
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13
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Abstract
The blood-brain barrier (BBB) protects the central nervous system (CNS) from unregulated exposure to the blood and its contents. The BBB also controls the blood-to-brain and brain-to-blood permeation of many substances, resulting in nourishment of the CNS, its homeostatic regulation and communication between the CNS and peripheral tissues. The cells forming the BBB communicate with cells of the brain and in the periphery. This highly regulated interface changes with healthy aging. Here, we review those changes, starting with morphology and disruption. Transporter changes include those for amyloid beta peptide, glucose and drugs. Brain fluid dynamics, pericyte health and basement membrane and glycocalyx compositions are all altered with healthy aging. Carrying the ApoE4 allele leads to an acceleration of most of the BBB's age-related changes. We discuss how alterations in the BBB that occur with healthy aging reflect adaptation to the postreproductive phase of life and may affect vulnerability to age-associated diseases.
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14
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Kuo YC, Lou YI, Rajesh R. Dual functional liposomes carrying antioxidants against tau hyperphosphorylation and apoptosis of neurons. J Drug Target 2020; 28:949-960. [PMID: 32338078 DOI: 10.1080/1061186x.2020.1761819] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/16/2019] [Revised: 04/20/2020] [Accepted: 04/24/2020] [Indexed: 10/24/2022]
Abstract
Quercetin (QU) and rosmarinic acid (RA) were loaded in phosphatidic acid-liposomes (QU/RA-PA-liposomes) with surface apolipoprotein E (ApoE) using a process of thin-film hydration, followed by covalent crosslinking to activate biological pathways for penetrating the blood-brain barrier (BBB) and redeeming the neuronal apoptosis from attack of β-amyloid 1-42 (Aβ1-42) and neurofibrillary tangles. The conjugation of liposomes with PA improved the activity of QU and RA against neurotoxicity of Aβ1-42. The fluorescent images of brain capillaries revealed that surface modification with ApoE improved the permeation ability of QU/RA-PA-ApoE-liposomes across the BBB. In addition, the highest therapeutic efficacy was obtained in the case of QU/RA-PA-ApoE-liposomes, compared to other QU/RA formulations studied using in vivo Aβ1-42-insulted rats mimicking Alzheimer's disease (AD). The cellular and molecular evidence from AD rats included the decrease in Aβ1-42 plaque formation and interleukin-6 secretion, increase in the neuronal count in Nissl staining, and reduction in the expression of phosphorylated extracellular signal-regulated kinase 1/2, c-Jun N-terminal kinase, p38 kinase and tau protein at serine 202 as well as caspase-3. The use of PA-ApoE-liposomes as a dual targeting formulation enhances the QU and RA ability to infiltrate the BBB, docks Aβ1-42 plaques and can be a potent approach to rescue degenerated neurons from AD.
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Affiliation(s)
- Yung-Chih Kuo
- Department of Chemical Engineering, National Chung Cheng University, Minxiong, Taiwan
- Advanced Institute of Manufacturing with High-tech Innovations, National Chung Cheng University, Minxiong, Taiwan
| | - Yung-I Lou
- Department of Accounting, Providence University, Taichung, Taiwan
| | - Rajendiran Rajesh
- Department of Chemical Engineering, National Chung Cheng University, Minxiong, Taiwan
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15
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Sera of elderly obstructive sleep apnea patients alter blood-brain barrier integrity in vitro: a pilot study. Sci Rep 2020; 10:11309. [PMID: 32647186 PMCID: PMC7347951 DOI: 10.1038/s41598-020-68374-8] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2019] [Accepted: 06/08/2020] [Indexed: 01/23/2023] Open
Abstract
Obstructive sleep apnea syndrome (OSAS) is characterized by repeated episodes of hypoxia during the night. The severity of the disorder can be evaluated using an apnea–hypopnea index (AHI). The physiological consequences are mainly cardiovascular and neuronal dysfunctions. One hypothesis to explain such associated neurological disorders is disruption of the blood–brain barrier (BBB), which protects the brain from endovascular cytotoxic compounds. We selected two subgroups of volunteers from the PROOF cohort study (France), a group of patients suffering newly diagnosed severe OSAS (AHI > 30/h) and a group showing no sleep apnea (AHI < 5/h). We exposed a human in vitro BBB model of endothelial cells (HBEC-5i) with sera of patients with and without OSAS. After exposure, we measured the apparent BBB permeability as well as tight junction and ABC transporter expression using whole cell ELISA. We showed that after incubation with sera from OSAS patients, there was a loss of integrity in the human in vitro BBB model; this was reflected by an increase in permeability (43%; p < 0.001) and correlated with a 50% and 40% decrease in tight junction protein expression of ZO-1 and claudin-5, respectively. At the same time, we observed an upregulation in Pgp protein expression (52%) and functionality, and a downregulation in BCRP expression (52%). Our results demonstrated that severe BBB disorder after exposure to sera from OSAS patients was reflected by an opening of the BBB.
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16
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Rhea EM, Raber J, Banks WA. ApoE and cerebral insulin: Trafficking, receptors, and resistance. Neurobiol Dis 2020; 137:104755. [PMID: 31978603 PMCID: PMC7050417 DOI: 10.1016/j.nbd.2020.104755] [Citation(s) in RCA: 32] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/30/2019] [Revised: 01/13/2020] [Accepted: 01/20/2020] [Indexed: 12/16/2022] Open
Abstract
Central nervous system (CNS) insulin resistance is associated with Alzheimer's disease (AD). In addition, the apolipoprotein E4 (apoE4) isoform is a risk factor for AD. The connection between these two factors in relation to AD is being actively explored. We summarize this literature with a focus on the transport of insulin and apoE across the blood-brain barrier (BBB) and into the CNS, the impact of apoE and insulin on the BBB, and the interactions between apoE, insulin, and the insulin receptor once present in the CNS. We highlight how CNS insulin resistance is apparent in AD and potential ways to overcome this resistance by repurposing currently approved drugs, with apoE genotype taken into consideration as the treatment response following most interventions is apoE isoform-dependent. This review is part of a special issue focusing on apoE in AD and neurodegeneration.
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Affiliation(s)
- Elizabeth M Rhea
- Research and Development, Veterans Affairs Puget Sound Healthcare System, Seattle, WA 98108, United States of America; Department of Medicine, University of Washington, Seattle, WA 98195, United States of America.
| | - Jacob Raber
- Department of Behavioral Neuroscience, Oregon Health & Science University, Portland, OR 97239, United States of America; Departments of Neurology and Radiation Medicine, Division of Neuroscience, ONPRC, Oregon Health & Science University, Portland, OR 97239, United States of America
| | - William A Banks
- Research and Development, Veterans Affairs Puget Sound Healthcare System, Seattle, WA 98108, United States of America; Department of Medicine, University of Washington, Seattle, WA 98195, United States of America
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17
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Liyanage SI, Weaver DF. Misfolded proteins as a therapeutic target in Alzheimer's disease. ADVANCES IN PROTEIN CHEMISTRY AND STRUCTURAL BIOLOGY 2020; 118:371-411. [PMID: 31928732 DOI: 10.1016/bs.apcsb.2019.08.003] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
For decades, Alzheimer's Disease (AD) was defined as a disorder of protein misfolding and aggregation. In particular, the extracellular peptide fragment: amyloid-β (Aβ), and the intracellular microtubule-associated protein: tau, were thought to initiate a neurodegenerative cascade which culminated in AD's progressive loss of memory and executive function. As such, both proteins became the focus of intense scrutiny, and served as the principal pathogenic target for hundreds of clinical trials. However, with varying efficacy, none of these investigations produced a disease-modifying therapy - offering patients with AD little recourse aside from transient, symptomatic medications. The near universal failure of clinical trials is unprecedented for a major research discipline. In part, this has motivated an increasing skepticism of the relevance of protein misfolding to AD's etiology. Several recent observations, principally the presence of significant protein pathologies in non-demented seniors, have lent credence to an apparent cursory role for Aβ and tau. Herein, we review both Aβ and tau, examining the processes from their biosynthesis to their pathogenesis and evaluate their vulnerability to medicinal intervention. We further attempt to reconcile the apparent failure of trials with the potential these targets hold. Ultimately, we seek to answer if protein misfolding is a viable platform in the pursuit of a disease-arresting strategy for AD.
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Affiliation(s)
- S Imindu Liyanage
- Krembil Research Institute, University Health Network, Toronto, ON, Canada
| | - Donald F Weaver
- Krembil Research Institute, University Health Network, Toronto, ON, Canada; Departments of Medicine (Neurology), Chemistry and Pharmaceutical Sciences, University of Toronto, Toronto, ON, Canada
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18
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Abstract
Neuroinflammation is implicated in contributing to a variety of neurologic and somatic illnesses including Alzheimer's disease (AD), Parkinson's disease (PD), and depression. In this chapter, we focus on the role of neuroinflammation in mediating these three illnesses and portray interactions between the immune response and the central nervous system in the context of sex differences in disease progression. The majority of this chapter is supported by clinical findings; however, we occasionally utilize preclinical models where human studies are currently lacking. We begin by detailing the pathology of neuroinflammation, distinguishing between acute and chronic inflammation, and examining contributions from the innate and adaptive immune systems. Next, we summarize potential mechanisms of immune cell mediators including interleukin-1 beta (IL-1β), tumor necrosis factor α, and IL-6 in AD, PD, and depression development. Given the strong sex bias seen in these illnesses, we additionally examine the role of sex hormones, e.g., estrogen and testosterone in mediating neuroinflammation at the cellular level. Systematically, we detail how sex hormones may contribute to distinct behavioral and clinical symptoms and prognosis between males and females with AD, PD, or depression. Finally, we highlight the possible role of exercise in alleviating neuroinflammation, as well as evidence that antiinflammatory drug therapies improve cognitive symptoms observed in brain-related diseases.
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Affiliation(s)
- Deepika Mukhara
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, United States
| | - Unsong Oh
- Department of Neurology, Virginia Commonwealth University, Richmond, VA, United States
| | - Gretchen N Neigh
- Department of Anatomy and Neurobiology, Virginia Commonwealth University, Richmond, VA, United States.
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19
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Lopez OL, Klunk WE, Mathis CA, Snitz BE, Chang Y, Tracy RP, Kuller LH. Relationship of amyloid-β1-42 in blood and brain amyloid: Ginkgo Evaluation of Memory Study. Brain Commun 2019; 2:fcz038. [PMID: 31998865 PMCID: PMC6976616 DOI: 10.1093/braincomms/fcz038] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/27/2019] [Revised: 10/24/2019] [Accepted: 11/25/2019] [Indexed: 12/13/2022] Open
Abstract
A blood test that predicts the extent of amyloid plaques in the brain and risk of Alzheimer's disease would have important benefits for the early identification of higher risk of dementia and Alzheimer's disease and the evaluation of new preventative therapies. The goal of this study was to determine whether plasma levels of amyloid-β1-42, 1-40 and the amyloid-β1-42/1-40 ratio among participants in the Pittsburgh centre of the Ginkgo Evaluation of Memory Study were related to the extent of brain fibrillar amyloid plaques measured in 2009 using Pittsburgh compound-B PET imaging, hippocampal volume, cortical thickness in the temporal lobe and white matter lesions. There were 194 participants who had Pittsburgh compound-B measurements in 2009 with the mean age of 85 years; 96% were white and 60% men. Pittsburgh compound-B positivity was defined as a standardized uptake value ratio of ≥1.57. Amyloid-β in blood was measured using a sandwich enzyme-linked immunosorbent assay developed by Eli Lilly and modified at the University of Vermont. All participants were nondemented as of 2008 at the time of study close out. The study sample included 160 with blood samples drawn in 2000-02 and 133 from 2009 and also had brain amyloid measured in 2009. All blood samples were analysed at the same time in 2009. Plasma amyloid-β1-42 was inversely related to the percent Pittsburgh compound-B positive (standardized uptake value ratio ≥1.57), β -0.04, P = 0.005. Practically all participants who were apolipoprotein-E4 positive at older ages were also Pittsburgh compound-B positive for fibrillar amyloid. Among apolipoprotein-E4-negative participants, quartiles of amyloid-β1-42 were inversely related to Pittsburgh compound-B positivity. In multiple regression models, plasma amyloid-β1-42 measured in 2000-02 or 2009 were significantly and inversely related to Pittsburgh compound-B positivity as was the amyloid-β1-42/1-40 ratio. There was a 4-fold increase in the odds ratio for the presence of Pittsburgh compound-B positivity in the brain in 2009 for the first quartile of amyloid-β1-42 as compared with the fourth quartile in the multiple logistic model. This is one of the first longitudinal studies to evaluate the relationship between amyloid-β1-42 in the blood and the extent of brain amyloid deposition measured by PET imaging using Pittsburgh compound-B. Our findings showed that remote and recent low plasma amyloid-β1-42 levels were inversely associated with brain amyloid deposition in cognitively normal individuals. However, changes in plasma amyloid-β1-42 over time (8 years) were small and not related to the amount of Pittsburgh compound-B.
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Affiliation(s)
- Oscar L Lopez
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15261, USA.,Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - William E Klunk
- Department of Psychiatry, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Beth E Snitz
- Department of Neurology, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Yuefang Chang
- Department of Neurosurgery, University of Pittsburgh, Pittsburgh, PA 15261, USA.,Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
| | - Russell P Tracy
- Department of Pathology and Laboratory Medicine, Larner College of Medicine, University of Vermont, Burlington, VT 05405, USA
| | - Lewis H Kuller
- Department of Epidemiology, Graduate School of Public Health, University of Pittsburgh, Pittsburgh, PA 15261, USA
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20
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Stewart KC, Subramanian D, Neal UJ, Hanson AJ. APOE Genotype Influences Postprandial Blood Pressure after High Fat Feeding in Older Adults. J Nutr Health Aging 2019; 23:408-413. [PMID: 31021357 PMCID: PMC6544369 DOI: 10.1007/s12603-019-1167-0] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
OBJECTIVE Postprandial hypotension (PPH) is a common phenomenon among older adults. The degree to which individuals experience PPH is related to cerebrovascular risk factors and the presence of neurodegenerative diseases such as Alzheimer's disease (AD). Carrier status of the E4 allele of the apolipoprotein E (APOE) gene is a risk factor for AD and influences a variety of responses to metabolic and dietary interventions. However, it is unknown whether APOE genotype influences the risk of PPH and whether type of meal can mediate that response. DESIGN Acute meal study with a crossover design. PARTICIPANTS 32 cognitively healthy older adults with (n=18) and without (n=14) E4+ carrier status. INTERVENTION As a part of an ongoing meal study we examined the postprandial blood pressure response after ingestion of a high carbohydrate (HCM) and high fat meal (HFM). MEASUREMENTS Blood pressure measurements were taken at 7 time points and change scores, area under the curve (AUC) scores were calculated. Data were analyzed by repeated measures ANOVA as well as Pearson correlation. RESULTS Both meals produced a sustained drop in systolic (SBP) and diastolic (DBP) blood pressure, with 37.5% of participants meeting criteria for PPH. Participants carrying the E4+ risk gene experienced a larger decrease in SBP than E4- participants, and this was significantly different after the HFM (E4+ AUC = -30.8 ± 7.6, E4- AUC = -0.2 ± 8.7, p=0.015). Increasing age was associated with a larger drop in postprandial blood pressure but only for the E4+ group after the HFM (p=0.002). CONCLUSIONS These data suggest that E4+ individuals experience a greater postprandial blood pressure response particularly following high fat feeding, and this effect becomes more pronounced with age. The prevalence of PPH may play a role in the development of AD and may be mediated by diet.
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Affiliation(s)
- K C Stewart
- Angela J Hanson, MD, Assistant Professor, Geriatric Medicine, University of Washington School of Medicine, 325 9th Ave, Box 359755, Seattle, WA, USA 98104, Phone: 206-897-5393, Fax: 206-744-9976,
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Ott BR, Jones RN, Daiello LA, de la Monte SM, Stopa EG, Johanson CE, Denby C, Grammas P. Blood-Cerebrospinal Fluid Barrier Gradients in Mild Cognitive Impairment and Alzheimer's Disease: Relationship to Inflammatory Cytokines and Chemokines. Front Aging Neurosci 2018; 10:245. [PMID: 30186149 PMCID: PMC6110816 DOI: 10.3389/fnagi.2018.00245] [Citation(s) in RCA: 56] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/04/2017] [Accepted: 07/25/2018] [Indexed: 01/30/2023] Open
Abstract
Background: The pathophysiology underlying altered blood-cerebrospinal fluid barrier (BCSFB) function in Alzheimer's disease (AD) is unknown but may relate to endothelial cell activation and cytokine mediated inflammation. Methods: Cerebrospinal fluid (CSF) and peripheral blood were concurrently collected from cognitively healthy controls (N = 21) and patients with mild cognitive impairment (MCI) (N = 8) or AD (N = 11). The paired serum and CSF samples were assayed for a panel of cytokines, chemokines, and related trophic factors using multiplex ELISAs. Dominance analysis models were conducted to determine the relative importance of the inflammatory factors in relationship to BCSFB permeability, as measured by CSF/serum ratios for urea, creatinine, and albumin. Results: BCSFB disruption to urea, a small molecule distributed by passive diffusion, had a full model coefficient of determination (r2) = 0.35, and large standardized dominance weights (>0.1) for monocyte chemoattractant protein-1, interleukin (IL)-15, IL-1rα, and IL-2 in serum. BCSFB disruption to creatinine, a larger molecule governed by active transport, had a full model r2 = 0.78, and large standardized dominance weights for monocyte inhibitor protein-1b in CSF and tumor necrosis factor-α in serum. BCSFB disruption to albumin, a much larger molecule, had a full model r2 = 0.62, and large standardized dominance weights for IL-17a, interferon-gamma, IL-2, and VEGF in CSF, as well IL-4 in serum. Conclusions: Inflammatory proteins have been widely documented in the AD brain. The results of the current study suggest that changes in BCSFB function resulting in altered permeability and transport are related to expression of specific inflammatory proteins, and that the shifting distribution of these proteins from serum to CSF in AD and MCI is correlated with more severe perturbations in BCSFB function.
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Affiliation(s)
- Brian R. Ott
- Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, United States,George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, United States,*Correspondence: Brian R. Ott
| | - Richard N. Jones
- Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, United States
| | - Lori A. Daiello
- Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, United States
| | - Suzanne M. de la Monte
- George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, United States,Division of Neuropathology, Department of Pathology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, United States
| | - Edward G. Stopa
- George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, United States,Division of Neuropathology, Department of Pathology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, United States
| | - Conrad E. Johanson
- Department of Neurosurgery, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, United States
| | - Charles Denby
- Department of Neurology, Alpert Medical School of Brown University, Rhode Island Hospital, Providence, RI, United States
| | - Paula Grammas
- George & Anne Ryan Institute for Neuroscience, University of Rhode Island, Kingston, RI, United States
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Kuller LH. A new era for dementia epidemiology: Alzheimer’s disease, hardening of arteries, or just old age? Eur J Epidemiol 2018; 33:613-616. [DOI: 10.1007/s10654-018-0420-x] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/08/2018] [Accepted: 06/12/2018] [Indexed: 12/18/2022]
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Zhang L, Sun C, Jin Y, Gao K, Shi X, Qiu W, Ma C, Zhang L. Dickkopf 3 (Dkk3) Improves Amyloid-β Pathology, Cognitive Dysfunction, and Cerebral Glucose Metabolism in a Transgenic Mouse Model of Alzheimer’s Disease. J Alzheimers Dis 2017; 60:733-746. [DOI: 10.3233/jad-161254] [Citation(s) in RCA: 9] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/18/2023]
Affiliation(s)
- Li Zhang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
- Neuroscience Center, Chinese Academy of Medical Sciences, Beijing, China
| | - Caixian Sun
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
| | - Yaxi Jin
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
| | - Kai Gao
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
| | - Xudong Shi
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
| | - Wenying Qiu
- Neuroscience Center, Chinese Academy of Medical Sciences, Beijing, China
- Department of Human Anatomy, Histology and Embryology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Chao Ma
- Neuroscience Center, Chinese Academy of Medical Sciences, Beijing, China
- Department of Human Anatomy, Histology and Embryology, Institute of Basic Medical Sciences, Chinese Academy of Medical Sciences, School of Basic Medicine, Peking Union Medical College, Beijing, China
| | - Lianfeng Zhang
- Key Laboratory of Human Disease Comparative Medicine, Ministry of Health, Institute of Laboratory Animal Sciences, Chinese Academy of Medical Sciences and Comparative Medical Center, Peking Union Medical College, Beijing, China
- Neuroscience Center, Chinese Academy of Medical Sciences, Beijing, China
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Zuroff L, Daley D, Black KL, Koronyo-Hamaoui M. Clearance of cerebral Aβ in Alzheimer's disease: reassessing the role of microglia and monocytes. Cell Mol Life Sci 2017; 74:2167-2201. [PMID: 28197669 PMCID: PMC5425508 DOI: 10.1007/s00018-017-2463-7] [Citation(s) in RCA: 159] [Impact Index Per Article: 22.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2016] [Revised: 01/07/2017] [Accepted: 01/11/2017] [Indexed: 01/03/2023]
Abstract
Deficiency in cerebral amyloid β-protein (Aβ) clearance is implicated in the pathogenesis of the common late-onset forms of Alzheimer’s disease (AD). Accumulation of misfolded Aβ in the brain is believed to be a net result of imbalance between its production and removal. This in turn may trigger neuroinflammation, progressive synaptic loss, and ultimately cognitive decline. Clearance of cerebral Aβ is a complex process mediated by various systems and cell types, including vascular transport across the blood–brain barrier, glymphatic drainage, and engulfment and degradation by resident microglia and infiltrating innate immune cells. Recent studies have highlighted a new, unexpected role for peripheral monocytes and macrophages in restricting cerebral Aβ fibrils, and possibly soluble oligomers. In AD transgenic (ADtg) mice, monocyte ablation or inhibition of their migration into the brain exacerbated Aβ pathology, while blood enrichment with monocytes and their increased recruitment to plaque lesion sites greatly diminished Aβ burden. Profound neuroprotective effects in ADtg mice were further achieved through increased cerebral recruitment of myelomonocytes overexpressing Aβ-degrading enzymes. This review summarizes the literature on cellular and molecular mechanisms of cerebral Aβ clearance with an emphasis on the role of peripheral monocytes and macrophages in Aβ removal.
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Affiliation(s)
- Leah Zuroff
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, 127 S. San Vicente, AHSP A8115, Los Angeles, CA, 90048, USA.,Perelman School of Medicine at the University of Pennsylvania, Philadelphia, PA, 19104, USA
| | - David Daley
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, 127 S. San Vicente, AHSP A8115, Los Angeles, CA, 90048, USA
| | - Keith L Black
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, 127 S. San Vicente, AHSP A8115, Los Angeles, CA, 90048, USA
| | - Maya Koronyo-Hamaoui
- Department of Neurosurgery, Maxine Dunitz Neurosurgical Institute, Cedars-Sinai Medical Center, 127 S. San Vicente, AHSP A8115, Los Angeles, CA, 90048, USA. .,Department of Biomedical Sciences, Cedars-Sinai Medical Center, Los Angeles, CA, 90048, USA.
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APOE ε4 status is associated with white matter hyperintensities volume accumulation rate independent of AD diagnosis. Neurobiol Aging 2017; 53:67-75. [PMID: 28235680 DOI: 10.1016/j.neurobiolaging.2017.01.014] [Citation(s) in RCA: 40] [Impact Index Per Article: 5.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/02/2016] [Revised: 01/06/2017] [Accepted: 01/11/2017] [Indexed: 11/24/2022]
Abstract
To assess the relationship between carriage of APOE ε4 allele and evolution of white matter hyperintensities (WMHs) volume, we longitudinally studied 339 subjects from the Alzheimer's Disease Neuroimaging Initiative cohort with diagnoses ranging from normal controls to probable Alzheimer's disease (AD). A purpose-built longitudinal automatic method was used to segment WMH using constraints derived from an atlas-based model selection applied to a time-averaged image. Linear mixed models were used to evaluate the differences in rate of change across diagnosis and genetic groups. After adjustment for covariates (age, sex, and total intracranial volume), homozygous APOE ε4ε4 subjects had a significantly higher rate of WMH accumulation (22.5% per year 95% CI [14.4, 31.2] for a standardized population having typical values of covariates) compared with the heterozygous (ε4ε3) subjects (10.0% per year [6.7, 13.4]) and homozygous ε3ε3 (6.6% per year [4.1, 9.3]) subjects. Rates of accumulation increased with diagnostic severity; controls accumulated 5.8% per year 95% CI: [2.2, 9.6] for the standardized population, early mild cognitive impairment 6.6% per year [3.9, 9.4], late mild cognitive impairment 12.5% per year [8.2, 17.0] and AD subjects 14.7% per year [6.0, 24.0]. Following adjustment for APOE status, these differences became nonstatistically significant suggesting that APOE ε4 genotype is the major driver of accumulation of WMH volume rather than diagnosis of AD.
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Vallée A, Lecarpentier Y. Alzheimer Disease: Crosstalk between the Canonical Wnt/Beta-Catenin Pathway and PPARs Alpha and Gamma. Front Neurosci 2016; 10:459. [PMID: 27807401 PMCID: PMC5069291 DOI: 10.3389/fnins.2016.00459] [Citation(s) in RCA: 98] [Impact Index Per Article: 12.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/03/2016] [Accepted: 09/22/2016] [Indexed: 12/25/2022] Open
Abstract
The molecular mechanisms underlying the pathophysiology of Alzheimer's disease (AD) are still not fully understood. In AD, Wnt/beta-catenin signaling has been shown to be downregulated while the peroxisome proliferator-activated receptor (PPAR) gamma (mARN and protein) is upregulated. Certain neurodegenerative diseases share the same Wnt/beta-catenin/PPAR gamma profile, such as bipolar disorder and schizophrenia. Conversely, other NDs share an opposite profile, such as amyotrophic lateral sclerosis, Parkinson's disease, Huntington's disease, multiple sclerosis, and Friedreich's ataxia. AD is characterized by the deposition of extracellular Abeta plaques and the formation of intracellular neurofibrillary tangles in the central nervous system (CNS). Activation of Wnt signaling or inhibition of both glycogen synthase kinase-3beta and Dickkopf 1, two key negative regulators of the canonical Wnt pathway, are able to protect against Abeta neurotoxicity and to ameliorate cognitive performance in AD patients. Although PPAR gamma is upregulated in AD patients, and despite the fact that it has been shown that the PPAR gamma and Wnt/beta catenin pathway systems work in an opposite manner, PPAR gamma agonists diminish learning and memory deficits, decrease Abeta activation of microglia, and prevent hippocampal and cortical neurons from dying. These beneficial effects observed in AD transgenic mice and patients might be partially due to the anti-inflammatory properties of PPAR gamma agonists. Moreover, activation of PPAR alpha upregulates transcription of the alpha-secretase gene and represents a new therapeutic treatment for AD. This review focuses largely on the behavior of two opposing pathways in AD, namely Wnt/beta-catenin signaling and PPAR gamma. It is hoped that this approach may help to develop novel AD therapeutic strategies integrating PPAR alpha signaling.
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Affiliation(s)
- Alexandre Vallée
- CHU Amiens Picardie, Université Picardie Jules VerneAmiens, France
- Experimental and Clinical Neurosciences Laboratory, INSERM U1084, University of PoitiersPoitiers, France
- AP-HP, Epidemiology and Clinical Research Department, University Hospital Bichat-Claude BernardParis, France
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Salameh TS, Rhea EM, Banks WA, Hanson AJ. Insulin resistance, dyslipidemia, and apolipoprotein E interactions as mechanisms in cognitive impairment and Alzheimer's disease. Exp Biol Med (Maywood) 2016; 241:1676-83. [PMID: 27470930 PMCID: PMC4999626 DOI: 10.1177/1535370216660770] [Citation(s) in RCA: 31] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/11/2022] Open
Abstract
An increased risk for Alzheimer's disease is associated with dyslipidemia and insulin resistance. A separate literature shows the genetic risk for developing Alzheimer's disease is strongly correlated to the presence of the E4 isoform of the apolipoprotein E carrier protein. Understanding how apolipoprotein E carrier protein, lipids, amyloid β peptides, glucose, central nervous system insulin, and peripheral insulin interact with one another in Alzheimer's disease is an area of increasing interest. Here, we will review the evidence relating apolipoprotein E carrier protein, lipids, and insulin action to Alzheimer's disease and Aβ peptides and then propose mechanisms as to how these factors might interact with one another to impair cognition and promote Alzheimer's disease.
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Affiliation(s)
- Therese S Salameh
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Elizabeth M Rhea
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - William A Banks
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
| | - Angela J Hanson
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA 98108, USA Division of Gerontology and Geriatric Medicine, Department of Medicine, University of Washington School of Medicine, Seattle, WA 98195, USA
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Zhao Y, Li D, Zhao J, Song J, Zhao Y. The role of the low-density lipoprotein receptor–related protein 1 (LRP-1) in regulating blood-brain barrier integrity. Rev Neurosci 2016; 27:623-34. [PMID: 27206317 DOI: 10.1515/revneuro-2015-0069] [Citation(s) in RCA: 42] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/15/2015] [Accepted: 03/25/2016] [Indexed: 12/18/2022]
Abstract
AbstractThe blood-brain barrier (BBB) is a protective structure that helps maintaining the homeostasis in cerebral microenvironment by limiting the passage of molecules into the brain. BBB is formed by closely conjugated endothelial cells, with astrocytic endfeet surrounded and extracellular matrix (ECM) consolidated. Numerous neurological diseases can cause disturbance of BBB, leading to brain edema and neurological dysfunctions. The low-density lipoprotein (LDL) receptor–related protein 1 (LRP-1), a member of the LDL receptor gene family, is involved in a lot of important processes in the brain under both physiological and pathological conditions. As a membrane receptor, LRP-1 interacts with a variety of ligands and mediates the internalization of several important substances. LRP-1 is found responsible for inducing the opening of BBB following ischemic attack. It has also been reported that LRP-1 regulates several tight junction proteins and mediates the clearance of major ECM-degrading proteinases. In this review, we briefly discussed the role of LRP-1 in regulating BBB integrity by modulating tight junction proteins, endothelial cells and the remodeling of ECM.
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Affiliation(s)
- Yahui Zhao
- 1Department of Neurosurgery, the First Affiliated Hospital of Xi’, and Jiaotong University College of Medicine, Xi’an 710061, Shaanxi Province, China
| | - Dandong Li
- 2Department of Neurosurgery, the Second Affiliated Hospital of Wenzhou Medical University, Wenzhou 325027, Zhejiang Province, China
| | - Junjie Zhao
- 1Department of Neurosurgery, the First Affiliated Hospital of Xi’, and Jiaotong University College of Medicine, Xi’an 710061, Shaanxi Province, China
| | - Jinning Song
- 1Department of Neurosurgery, the First Affiliated Hospital of Xi’, and Jiaotong University College of Medicine, Xi’an 710061, Shaanxi Province, China
| | - Yonglin Zhao
- 1Department of Neurosurgery, the First Affiliated Hospital of Xi’, and Jiaotong University College of Medicine, Xi’an 710061, Shaanxi Province, China
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Zhou X, Yang C, Liu Y, Li P, Yang H, Dai J, Qu R, Yuan L. Lipid rafts participate in aberrant degradative autophagic-lysosomal pathway of amyloid-beta peptide in Alzheimer's disease. Neural Regen Res 2014; 9:92-100. [PMID: 25206748 PMCID: PMC4146310 DOI: 10.4103/1673-5374.125335] [Citation(s) in RCA: 10] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/25/2013] [Indexed: 11/04/2022] Open
Abstract
Amyloid-beta peptide is the main component of amyloid plaques, which are found in Alzheimer's disease. The generation and deposition of amyloid-beta is one of the crucial factors for the onset and progression of Alzheimer's disease. Lipid rafts are glycolipid-rich liquid domains of the plasma membrane, where certain types of protein tend to aggregate and intercalate. Lipid rafts are involved in the generation of amyloid-beta oligomers and the formation of amyloid-beta peptides. In this paper, we review the mechanism by which lipid rafts disturb the aberrant degradative autophagic-lysosomal pathway of amyloid-beta, which plays an important role in the pathological process of Alzheimer's disease. Moreover, we describe this mechanism from the view of the Two-system Theory of fasciology and thus, suggest that lipid rafts may be a new target of Alzheimer's disease treatment.
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Affiliation(s)
- Xin Zhou
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guang-dong Province, China
| | - Chun Yang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guang-dong Province, China
| | - Yufeng Liu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guang-dong Province, China
| | - Peng Li
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guang-dong Province, China
| | - Huiying Yang
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guang-dong Province, China
| | - Jingxing Dai
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guang-dong Province, China
| | - Rongmei Qu
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guang-dong Province, China
| | - Lin Yuan
- Department of Human Anatomy, Histology and Embryology, School of Basic Medical Sciences, Southern Medical University, Guangzhou, Guang-dong Province, China
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Wan W, Xia S, Kalionis B, Liu L, Li Y. The role of Wnt signaling in the development of Alzheimer's disease: a potential therapeutic target? BIOMED RESEARCH INTERNATIONAL 2014; 2014:301575. [PMID: 24883305 PMCID: PMC4026919 DOI: 10.1155/2014/301575] [Citation(s) in RCA: 52] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/12/2013] [Accepted: 04/10/2014] [Indexed: 12/31/2022]
Abstract
Accumulating evidence supports a key role for Wnt signaling in the development of the central nervous system (CNS) during embryonic development and in the regulation of the structure and function of the adult brain. Alzheimer's disease (AD) is the most common form of senile dementia, which is characterized by β -amyloid (A β ) deposition in specific brain regions. However, the molecular mechanism underlying AD pathology remains elusive. Dysfunctional Wnt signaling is associated with several diseases such as epilepsy, cancer, metabolic disease, and AD. Increasing evidence suggests that downregulation of Wnt signaling, induced by A β , is associated with disease progression of AD. More importantly, persistent activation of Wnt signaling through Wnt ligands, or inhibition of negative regulators of Wnt signaling, such as Dickkopf-1 (DKK-1) and glycogen synthase kinase-3 β (GSK-3 β ) that are hyperactive in the disease state, is able to protect against A β toxicity and ameliorate cognitive performance in AD. Together, these data suggest that Wnt signaling might be a potential therapeutic target of AD. Here, we review recent studies related to the progression of AD where Wnt signaling might be relevant and participate in the development of the disease. Then, we focus on the potential relevance of manipulating the Wnt signaling pathway for the treatment of AD.
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Affiliation(s)
- Wenbin Wan
- Geriatrics Department of Traditional Chinese Medicine, Huadong Hospital, Fudan University, Shanghai 200040, China
| | - Shijin Xia
- Shanghai Institute of Geriatrics, Huadong Hospital, Fudan University, Shanghai 200040, China
| | - Bill Kalionis
- Department of Perinatal Medicine Pregnancy Research Centre and University of Melbourne Department of Obstetrics and Gynaecology, Royal Women's Hospital, Parkville, VIC 3052, Australia
| | - Lumei Liu
- Geriatrics Department of Traditional Chinese Medicine, Huadong Hospital, Fudan University, Shanghai 200040, China
| | - Yaming Li
- Geriatrics Department of Traditional Chinese Medicine, Huadong Hospital, Fudan University, Shanghai 200040, China
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Nielsen NS, Poulsen ET, Klintworth GK, Enghild JJ. Insight into the Protein Composition of Immunoglobulin Light Chain Deposits of Eyelid, Orbital and Conjunctival Amyloidosis. ACTA ACUST UNITED AC 2014; Suppl 8. [PMID: 26500418 DOI: 10.4172/jpb.s8-002] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022]
Abstract
Amyloidosis is a disease characterized by the formation of extracellular amyloid deposits. Immunoglobulin light-chain amyloidosis can appear as a local disorder presenting with mild symptoms or as a life threatening systemic disease. The systemic form of immunoglobulin light-chain amyloidosis is the most common type of amyloidosis in western countries although it is a rare disease. Identification of the proteins forming amyloid fibrils is essential for the diagnosis of the disease and knowledge about the overall protein composition of the deposits may lead to a larger understanding of the deposition events thereby facilitating a more detailed picture of the molecular pathology. In this pilot study, we investigated the protein composition of amyloid deposits isolated from human specimens of the eyelid, conjunctiva, and orbit. Deposits and internal control tissue (patient tissue without apparent deposits) were procured by laser capture microdissection. Proteins in the captured amyloid and control samples were quantified by liquid chromatography tandem mass spectrometry using the label-free exponential modified Protein Abundance Index (emPAI) method. Immunoglobulin light chain kappa or lambda was found to be the most predominant protein in the amyloid deposits from the eyelid, conjunctiva, and orbit. Five proteins, apolipoprotein A-I, carboxypeptidase B2 (TAFI), complement component C9, fibulin-1 and plasminogen were found solely across all amyloid but not in the control tissue. In addition, the protein profiles identified apolipoprotein E and serum amyloid P component to be associated with the immunoglobulin light chain deposits across all three tissues analyzed. The method used in this study provided high sensitivity and specificity for the type of amyloid and may provide additional information on the pathology of the amyloid deposits in the ocular tissues studied.
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Affiliation(s)
- Nadia Sukusu Nielsen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark
| | - Ebbe Toftgaard Poulsen
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark
| | - Gordon K Klintworth
- Departments of Pathology and Ophthalmology, Duke University Medical Center, Durham, North Carolina, USA
| | - Jan J Enghild
- Department of Molecular Biology and Genetics, Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark ; Interdisciplinary Nanoscience Center (iNANO) and Center for Insoluble Protein Structures (inSPIN), Aarhus University, Gustav Wieds Vej 10, 8000 Aarhus C, Denmark
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Janssen CI, Kiliaan AJ. Long-chain polyunsaturated fatty acids (LCPUFA) from genesis to senescence: The influence of LCPUFA on neural development, aging, and neurodegeneration. Prog Lipid Res 2014; 53:1-17. [DOI: 10.1016/j.plipres.2013.10.002] [Citation(s) in RCA: 270] [Impact Index Per Article: 27.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/16/2013] [Revised: 10/08/2013] [Accepted: 10/14/2013] [Indexed: 12/24/2022]
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Swaminathan S, Risacher SL, Yoder KK, West JD, Shen L, Kim S, Inlow M, Foroud T, Jagust WJ, Koeppe RA, Mathis CA, Shaw LM, Trojanowski JQ, Soares H, Aisen PS, Petersen RC, Weiner MW, Saykin AJ. Association of plasma and cortical amyloid beta is modulated by APOE ε4 status. Alzheimers Dement 2014; 10:e9-e18. [PMID: 23541187 PMCID: PMC3750076 DOI: 10.1016/j.jalz.2013.01.007] [Citation(s) in RCA: 32] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2012] [Revised: 01/10/2013] [Accepted: 01/16/2013] [Indexed: 10/27/2022]
Abstract
BACKGROUND Apolipoprotein E (APOE) ε4 allele's role as a modulator of the relationship between soluble plasma amyloid beta (Aβ) and fibrillar brain Aβ measured by Pittsburgh compound B positron emission tomography ([(11)C]PiB PET) has not been assessed. METHODS Ninety-six Alzheimer's Disease Neuroimaging Initiative participants with [(11)C]PiB scans and plasma Aβ1-40 and Aβ1-42 measurements at the time of PET scanning were included. Regional and voxelwise analyses of [(11)C]PiB data were used to determine the influence of APOE ε4 allele on association of plasma Aβ1-40, Aβ1-42, and Aβ1-40/Aβ1-42 with [(11)C]PiB uptake. RESULTS In APOE ε4- but not ε4+ participants, positive relationships between plasma Aβ1-40/Aβ1-42 and [(11)C]PiB uptake were observed. Modeling the interaction of APOE and plasma Aβ1-40/Aβ1-42 improved the explained variance in [(11)C]PiB binding compared with using APOE and plasma Aβ1-40/Aβ1-42 as separate terms. CONCLUSIONS The results suggest that plasma Aβ is a potential Alzheimer's disease biomarker and highlight the importance of genetic variation in interpretation of plasma Aβ levels.
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Affiliation(s)
- Shanker Swaminathan
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Shannon L Risacher
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Karmen K Yoder
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - John D West
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Li Shen
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Sungeun Kim
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - Mark Inlow
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Mathematics, Rose-Hulman Institute of Technology, Terre Haute, IN, USA
| | - Tatiana Foroud
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA
| | - William J Jagust
- Helen Wills Neuroscience Institute, University of California at Berkeley, Berkeley, CA, USA
| | - Robert A Koeppe
- Division of Nuclear Medicine, Department of Radiology, University of Michigan, Ann Arbor, MI, USA
| | - Chester A Mathis
- Department of Radiology, University of Pittsburgh, Pittsburgh, PA, USA
| | - Leslie M Shaw
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | - John Q Trojanowski
- Department of Pathology and Laboratory Medicine, University of Pennsylvania School of Medicine, Philadelphia, PA, USA
| | | | - Paul S Aisen
- Department of Neurosciences, University of California at San Diego, San Diego, CA, USA
| | - Ronald C Petersen
- Department of Neurology, Mayo Clinic and Foundation, Rochester, MN, USA
| | - Michael W Weiner
- Department of Veterans Affairs Medical Center, Center for Imaging of Neurodegenerative Diseases, San Francisco, CA, USA
| | - Andrew J Saykin
- Center for Neuroimaging, Department of Radiology and Imaging Sciences, Indiana University School of Medicine, Indianapolis, IN, USA; Department of Medical and Molecular Genetics, Indiana University School of Medicine, Indianapolis, IN, USA; Center for Computational Biology and Bioinformatics, Indiana University School of Medicine, Indianapolis, IN, USA.
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Karch A, Manthey H, Ponto C, Hermann P, Heinemann U, Schmidt C, Zerr I. Investigating the association of ApoE genotypes with blood-brain barrier dysfunction measured by cerebrospinal fluid-serum albumin ratio in a cohort of patients with different types of dementia. PLoS One 2013; 8:e84405. [PMID: 24386372 PMCID: PMC3874026 DOI: 10.1371/journal.pone.0084405] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/30/2013] [Accepted: 11/13/2013] [Indexed: 12/02/2022] Open
Abstract
Background Since more than a decade ApoE is known to be a strong risk factor for Alzheimer's disease (AD); however, molecular pathways mediating this risk are still unclear. In recent years it has been hypothesized that ApoE might play a role in the disintegration of blood-brain barrier (BBB). In the present study we addressed the question if ApoE genotypes might be associated with BBB function measured by albumin ratio (QAlb) in a large cohort of patients with different types of dementia. Methods Five hundred twenty (520) patients with Creutzfeldt-Jakob disease (CJD, n = 350), Alzheimer's disease (n = 71) and cerebral small vessel disease (n = 99) were assessed for their ApoE genotype. BBB function was measured in all patients using QAlb and was compared between ApoE genotypes. Dominant and additive genetic models were assumed in order to investigate the potential effect of ApoE on BBB function. Results We observed no systematic differences in QAlb between ApoE genotypes within the present study. Increased QAlb levels were shown for those without E3 allele in the subgroup of CJD patients when assuming a dominant genetic model (p = 0.035). This could not be confirmed for patients with other forms of dementia (p = 0.234). Discussion Although there was some evidence for a protective effect of E3 alleles in CJD patients, this study does not support the hypothesis of a systematic role of ApoE genotypes in BBB function in individuals with a diagnosis of dementia. Thus, changes in BBB function do not seem to contribute to the increased risk of cognitive decline associated with certain ApoE genotypes. The interpretation of the results of this study must take into account that BBB function was only assessed by measuring QAlb which has been shown to be a good marker for overall BBB integrity but might not reflect all qualities of the barrier.
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Affiliation(s)
- André Karch
- Department of Neurology, Clinical Dementia Centre, University Hospital Göttingen, Göttingen, Germany
- Department of Epidemiology, Helmholtz Centre for Infection Research, Braunschweig, Germany
- * E-mail:
| | - Henrike Manthey
- Department of Neurology, Clinical Dementia Centre, University Hospital Göttingen, Göttingen, Germany
| | - Claudia Ponto
- Department of Neurology, Clinical Dementia Centre, University Hospital Göttingen, Göttingen, Germany
| | - Peter Hermann
- Department of Neurology, Clinical Dementia Centre, University Hospital Göttingen, Göttingen, Germany
| | - Uta Heinemann
- Department of Neurology, Clinical Dementia Centre, University Hospital Göttingen, Göttingen, Germany
| | - Christian Schmidt
- Department of Neurology, Clinical Dementia Centre, University Hospital Göttingen, Göttingen, Germany
| | - Inga Zerr
- Department of Neurology, Clinical Dementia Centre, University Hospital Göttingen, Göttingen, Germany
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Liraglutide can reverse memory impairment, synaptic loss and reduce plaque load in aged APP/PS1 mice, a model of Alzheimer's disease. Neuropharmacology 2013; 76 Pt A:57-67. [PMID: 23973293 DOI: 10.1016/j.neuropharm.2013.08.005] [Citation(s) in RCA: 236] [Impact Index Per Article: 21.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/15/2013] [Revised: 08/06/2013] [Accepted: 08/08/2013] [Indexed: 12/27/2022]
Abstract
Type 2 diabetes is a risk factor in the development of Alzheimer's disease (AD). It has been shown that insulin signalling is desensitised in the brains of AD patients. The incretin hormone Glucagon-like peptide-1 (GLP-1) facilitates insulin signalling, and long-lasting analogues such as liraglutide (Victoza(®)) are on the market as type 2 diabetes treatments. We have previously shown that liraglutide improved cognitive function, reduced amyloid plaque deposition, inflammation, overall APP and oligomer levels and enhanced LTP when injected peripherally for two months in 7 month old APPswe/PS1ΔE9 (APP/PS1) mice. This showed that liraglutide has preventive effects at the early stage of AD development. The current study investigated whether Liraglutide would have restorative effects in late-stage Alzheimer's disease in mice. Accordingly, 14-month-old APP/PS1 and littermate control mice were injected with Liraglutide (25 nmol/kg bw) ip. for 2 months. Spatial memory was improved by Liraglutide-treatment in APP/PS1 mice compared with APP/PS1 saline-treated mice. Overall plaque load was reduced by 33%, and inflammation reduced by 30%, while neuronal progenitor cell count in the dentate gyrus was increased by 50%. LTP was significantly enhanced in APP/PS1 liraglutide-treated mice compared with APP/PS1 saline mice, corroborated with increased synapse numbers in hippocampus and cortex. Total brain APP and beta-amyloid oligomer levels were reduced in Liraglutide-treated APP/PS1 mice while IDE levels were increased. These results demonstrate that Liraglutide not only has preventive properties, but also can reverse some of the key pathological hallmarks of AD. Liraglutide is now being tested in clinical trials in AD patients. This article is part of the Special Issue entitled 'The Synaptic Basis of Neurodegenerative Disorders'.
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Fox M, Knapp LA, Andrews PW, Fincher CL. Hygiene and the world distribution of Alzheimer's disease: Epidemiological evidence for a relationship between microbial environment and age-adjusted disease burden. EVOLUTION MEDICINE AND PUBLIC HEALTH 2013; 2013:173-86. [PMID: 24481197 PMCID: PMC3868447 DOI: 10.1093/emph/eot015] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Indexed: 12/16/2022]
Abstract
People living in sanitized environments may be at greater Alzheimer's risk. We compare Alzheimer's rates in different countries in light of countries' historical and contemporary pathogen prevalence, sanitation, and urbanization. We find that countries that are less urbanized, with more pathogens and lower degree of sanitation have lower Alzheimer's rates. Background and objectives: Alzheimer’s disease (AD) shares certain etiological features with autoimmunity. Prevalence of autoimmunity varies between populations in accordance with variation in environmental microbial diversity. Exposure to microorganisms may improve individuals’ immunoregulation in ways that protect against autoimmunity, and we suggest that this may also be the case for AD. Here, we investigate whether differences in microbial diversity can explain patterns of age-adjusted AD rates between countries. Methodology: We use regression models to test whether pathogen prevalence, as a proxy for microbial diversity, across 192 countries can explain a significant amount of the variation in age-standardized AD disability-adjusted life-year (DALY) rates. We also review and assess the relationship between pathogen prevalence and AD rates in different world populations. Results: Based on our analyses, it appears that hygiene is positively associated with AD risk. Countries with greater degree of sanitation and lower degree of pathogen prevalence have higher age-adjusted AD DALY rates. Countries with greater degree of urbanization and wealth exhibit higher age-adjusted AD DALY rates. Conclusions and implications: Variation in hygiene may partly explain global patterns in AD rates. Microorganism exposure may be inversely related to AD risk. These results may help predict AD burden in developing countries where microbial diversity is rapidly diminishing. Epidemiological forecasting is important for preparing for future healthcare needs and research prioritization.
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Affiliation(s)
- Molly Fox
- Division of Biological Anthropology, Department of Anthropology and Archaeology, University of Cambridge, Pembroke Street, Cambridge CB2 3QY, UK, Department of Anthropology, University of Utah, 270 S 1400 E, Salt Lake City, UT 84112, USA, Department of Psychology, Neuroscience & Behaviour, McMaster University, 1280 Main Street W, Hamilton, ON L8S 4K1, Canada and Institute of Neuroscience and Psychology, University of Glasgow, 58 Hillhead Street, Glasgow G12 8QB, UK
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Fehér Á, Juhász A, László A, Pákáski M, Kálmán J, Janka Z. Association between the ABCG2 C421A polymorphism and Alzheimer's disease. Neurosci Lett 2013; 550:51-4. [DOI: 10.1016/j.neulet.2013.06.044] [Citation(s) in RCA: 38] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/21/2013] [Revised: 05/31/2013] [Accepted: 06/20/2013] [Indexed: 12/13/2022]
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Drummond ES, Muhling J, Martins RN, Wijaya LK, Ehlert EM, Harvey AR. Pathology associated with AAV mediated expression of beta amyloid or C100 in adult mouse hippocampus and cerebellum. PLoS One 2013; 8:e59166. [PMID: 23516609 PMCID: PMC3596293 DOI: 10.1371/journal.pone.0059166] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/29/2012] [Accepted: 02/13/2013] [Indexed: 11/18/2022] Open
Abstract
Accumulation of beta amyloid (Aβ) in the brain is a primary feature of Alzheimer’s disease (AD) but the exact molecular mechanisms by which Aβ exerts its toxic actions are not yet entirely clear. We documented pathological changes 3 and 6 months after localised injection of recombinant, bi-cistronic adeno-associated viral vectors (rAAV2) expressing human Aβ40-GFP, Aβ42-GFP, C100-GFP or C100V717F-GFP into the hippocampus and cerebellum of 8 week old male mice. Injection of all rAAV2 vectors resulted in wide-spread transduction within the hippocampus and cerebellum, as shown by expression of transgene mRNA and GFP protein. Despite the lack of accumulation of Aβ protein after injection with AAV vectors, injection of rAAV2-Aβ42-GFP and rAAV2- C100V717F-GFP into the hippocampus resulted in significantly increased microgliosis and altered permeability of the blood brain barrier, the latter revealed by high levels of immunoglobulin G (IgG) around the injection site and the presence of IgG positive cells. In comparison, injection of rAAV2-Aβ40-GFP and rAAV2-C100-GFP into the hippocampus resulted in substantially less neuropathology. Injection of rAAV2 vectors into the cerebellum resulted in similar types of pathological changes, but to a lesser degree. The use of viral vectors to express different types of Aβ and C100 is a powerful technique with which to examine the direct in vivo consequences of Aβ expression in different regions of the mature nervous system and will allow experimentation and analysis of pathological AD-like changes in a broader range of species other than mouse.
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Affiliation(s)
- Eleanor S Drummond
- School of Anatomy, Physiology and Human Biology, The University of Western Australia, Western Australia, Australia.
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Hinder LM, Vincent AM, Hayes JM, McLean LL, Feldman EL. Apolipoprotein E knockout as the basis for mouse models of dyslipidemia-induced neuropathy. Exp Neurol 2012; 239:102-10. [PMID: 23059459 DOI: 10.1016/j.expneurol.2012.10.002] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/19/2012] [Revised: 09/24/2012] [Accepted: 10/01/2012] [Indexed: 01/15/2023]
Abstract
Dyslipidemia has been identified as an important pathogenic risk factor for diabetic neuropathy, but current animal models do not adequately reproduce the lipid profile observed in human diabetics (increased triglycerides with an elevated LDL-cholesterol and reduced HDL-cholesterol). High fat feeding of mice produces hyperlipidemia, but mice are resistant to increases in the LDL to HDL ratio, reducing the potential for peripheral lipid deposits to impact neuropathy, as is postulated to occur in human subjects. Genetic manipulations provide an alternative approach to reproducing a neuropathic plasma lipid profile. Based on findings from the atherosclerosis literature, we began with knockout of ApoE. Since knockout of ApoE alone only partially mimics the human diabetic lipid profile, we examined the impact of its combination with a well-characterized model of type 2 diabetes exhibiting neuropathy, the db/db mouse. We added further gene manipulations to increase hyperlipidemia by using mice with both ApoE and ApoB48 knockout on the ob/+ (leptin mutation) mice. In all of these models, we found that either the db/db or ob/ob genotypes had increased body weight, hyperlipidemia, hyperglycemia, and evidence of neuropathy compared with the control groups (db/+ or ob/+, respectively). We found that ApoE knockout combined with leptin receptor knockout produced a lipid profile most closely modeling human dyslipidemia that promotes neuropathy. ApoE knockout combined with additional ApoB48 and leptin knockout produced similar changes of smaller magnitude, but, notably, an increase in HDL-cholesterol. Our data suggest that the overall effects of ApoE knockout, either directly upon nerve structure and function or indirectly on lipid metabolism, are insufficient to significantly alter the course of diabetic neuropathy. Although these models ultimately do not deliver optimal lipid profiles for translational diabetic neuropathy research, they do present glycemic and lipid profile properties of value for future therapeutic investigations.
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Affiliation(s)
- Lucy M Hinder
- Department of Neurology, University of Michigan, Ann Arbor, MI 48109, USA
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Kuller LH, Lopez OL. Dementia and Alzheimer's disease: a new direction.The 2010 Jay L. Foster Memorial Lecture. Alzheimers Dement 2012; 7:540-50. [PMID: 21889117 DOI: 10.1016/j.jalz.2011.05.901] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2011] [Accepted: 05/03/2011] [Indexed: 01/18/2023]
Abstract
BACKGROUND The modern era of Alzheimer's disease (AD) research began in the early 1980s with the establishment of AD research centers and expanded research programs at the National Institute on Aging. METHODS Over the past 30 years, there has been success in defining criteria for AD and dementia, association of important genetic disorders related to premature dementia in families, the association of apolipoprotein-E(4), and measurement of incidence and prevalence and selected risk factors. However, prevention and treatment have been elusive. RESULTS The development of new technologies, especially magnetic resonance imaging, positron emission tomography to measure amyloid in vivo in the brain and glucose metabolism, cerebrospinal fluid examination, better genetic markers, large-scale longitudinal epidemiology studies, and preventive clinical trials has rapidly begun a new era of research that offers opportunities to better understand etiology, that is, determinants of amyloid biology in the brain, neurofibrillary tangles, synaptic loss, and dementia. CONCLUSIONS There are three major hypotheses related to dementia: amyloid deposition and secondary synaptic loss as a unique disease, vascular injury, and "aging." New research must be hypothesis-driven and lead to testable approaches for treatment and prevention.
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Affiliation(s)
- Lewis H Kuller
- Department of Epidemiology, University of Pittsburgh, PA, USA.
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Bachmeier C, Paris D, Beaulieu-Abdelahad D, Mouzon B, Mullan M, Crawford F. A multifaceted role for apoE in the clearance of beta-amyloid across the blood-brain barrier. NEURODEGENER DIS 2012; 11:13-21. [PMID: 22572854 DOI: 10.1159/000337231] [Citation(s) in RCA: 41] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/03/2011] [Accepted: 02/10/2012] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND While apolipoprotein E4 (apoE4) is highly correlated with the development of Alzheimer's disease (AD), its role in AD pathology and, in particular, beta-amyloid (Aβ) removal from the brain, is not clearly defined. OBJECTIVE To elucidate the influence of apoE on the clearance of Aβ across the blood-brain barrier (BBB). METHODS Aβ(1-42) was intracerebrally administered to transgenic mice expressing human apoE isoforms and examined in the periphery. RESULTS apoE3 and apoE4 mice had 5 times and 2 times, respectively, more Aβ(1-42) appearing in the plasma than wild-type or apoE knockout mice, indicating an enhanced clearance of Aβ from the brain to the periphery. In vitro, unbound basolateral apoE3 (i.e., not bound to Aβ), and to a lesser extent unbound apoE4, at concentrations ≤10 nM facilitated basolateral-to-apical fluorescein-Aβ(1-42) transcytosis across a BBB model, while apoE isoforms bound to Aβ significantly disrupted Aβ transcytosis. Additionally, following apical exposure to the BBB model, we found that apoE4 bound to Aβ is able to penetrate the BBB more readily than apoE3 bound to Aβ and does so via the RAGE (receptor for advanced glycation end products) transporter. CONCLUSION These studies indicate a multifaceted, isoform-dependent role for apoE in the exchange of Aβ across the BBB and may partially explain the association of apoE4 and Aβ brain accumulation in AD.
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Kamphuis W, Orre M, Kooijman L, Dahmen M, Hol EM. Differential cell proliferation in the cortex of the appsweps1de9 alzheimer's disease mouse model. Glia 2012; 60:615-29. [DOI: 10.1002/glia.22295] [Citation(s) in RCA: 103] [Impact Index Per Article: 8.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/25/2011] [Accepted: 12/21/2011] [Indexed: 12/20/2022]
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Dominiczak MH, Caslake MJ. Apolipoproteins: metabolic role and clinical biochemistry applications. Ann Clin Biochem 2011; 48:498-515. [PMID: 22028427 DOI: 10.1258/acb.2011.011111] [Citation(s) in RCA: 133] [Impact Index Per Article: 10.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Abstract
Lipoprotein metabolism is dependent on apolipoproteins, multifunctional proteins that serve as templates for the assembly of lipoprotein particles, maintain their structure and direct their metabolism through binding to membrane receptors and regulation of enzyme activity. The three principal functions of lipoproteins are contribution to interorgan fuel (triglyceride) distribution (by means of the fuel transport pathway), to the maintenance of the extracellular cholesterol pool (by means of the overflow pathway) and reverse cholesterol transport. The most important clinical application of apolipoprotein measurements in the plasma is in the assessment of cardiovascular risk. Concentrations of apolipoprotein B and apolipoprotein AI (and their ratio) seem to be better markers of cardiovascular risk than conventional markers such as total cholesterol and LDL-cholesterol. Apolipoprotein measurements are also better standardized than the conventional tests. We suggest that measurements of apolipoprotein AI and apolipoprotein B are included as a part of the specialist lipid profile. We also suggest that lipoprotein (a) should be measured as part of the initial assessment of dyslipidaemias because of its consistent association with cardiovascular risk. Genotyping of apolipoprotein E isoforms remains useful in the investigation of mixed dyslipidaemias. Lastly, the role of postprandial metabolism is increasingly recognized in the context of atherogenesis, obesity and diabetes. This requires better markers of chylomicrons, very-low-density lipoproteins and remnant particles. Measurements of apolipoprotein B48 and remnant lipoprotein cholesterol are currently the key tests in this emerging field.
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Affiliation(s)
- Marek H Dominiczak
- NHS Greater Glasgow and Clyde Clinical Biochemistry Service and College of Medical, Veterinary and Life Sciences, University of Glasgow, Glasgow G12 0YN, UK.
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Jeynes B, Provias J. The case for blood-brain barrier dysfunction in the pathogenesis of Alzheimer's disease. J Neurosci Res 2011; 89:22-8. [PMID: 21046564 DOI: 10.1002/jnr.22527] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease that leads to a progressive loss of integrative and memory capacities of the brain. This is the predominant form of neurodegenerative dementia, with a growing prevalence of between 1 in 50 and 1 in 100 in North America. Numerous hypotheses related to the etiology of AD have developed over the years. However, among the various published hypotheses, the predominant one is related to the progressive and prominent accumulation of central nervous system β-amyloid peptide and the ensuing brain burden created. It is, therefore, important to consider the homeostatic mechanisms underlying β-amyloid transport dynamics between the brain and blood vascular compartments. As well, there is a dynamic interrelationship between soluble and insoluble forms of the peptide. Factors that underlie and regulate these dynamic processes are likely relevant to the end accumulation of β-amyloid peptide in the brain compartment and ultimately in insoluble forms, which is characteristic of, and significant for, the pathophysiology of the Alzheimer's brain. Significantly, and in particular relation to the amyloid burden theory mentioned above, it has been postulated that a dysfunctioning blood-brain barrier (BBB) may play a significant, if not critical, role in the pathogenesis of AD. By allowing the influx of injurious materials or agents into the brain or by impeding or blocking the efflux of those materials and/or agents, BBB-related neuronopathies and their associated sequelae could, and do, ensue.
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Affiliation(s)
- Brian Jeynes
- Faculty of Applied Health Sciences, Brock University, St. Catharine's, Ontario, Canada.
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Oxidative Stress and β-Amyloid Protein in Alzheimer’s Disease. Neuromolecular Med 2011; 13:223-50. [DOI: 10.1007/s12017-011-8155-9] [Citation(s) in RCA: 158] [Impact Index Per Article: 12.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/14/2011] [Accepted: 08/26/2011] [Indexed: 12/21/2022]
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Wang ZY, Miki T, Ding Y, Wang SJ, Gao YH, Wang XL, Wang YH, Yokoyama T, Warita K, Ohta KI, Suzuki S, Ohnishi T, Obama T, Bedi KS, Takeuchi Y, Shan BE. A high cholesterol diet given to apolipoprotein E-knockout mice has a differential effect on the various neurotrophin systems in the hippocampus. Metab Brain Dis 2011; 26:185-94. [PMID: 21826472 DOI: 10.1007/s11011-011-9252-z] [Citation(s) in RCA: 6] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 02/25/2011] [Accepted: 07/12/2011] [Indexed: 12/12/2022]
Abstract
Apolipoprotein E (apoE) is one of the major transporters of cholesterol in the body and is essential for maintaining various neural functions in the brain. Given that hypercholesterolemia is a risk factor in Alzheimer's disease (AD), it has been suggested that altered cholesterol metabolism may be involved in the development of the pathogenesis, including neural degeneration, commonly observed in AD patients. Neurotrophic factors and their receptors, which are known to regulate various neural functions, are also known to be altered in various neurodegenerative diseases. We therefore hypothesized that cholesterol metabolism may itself influence the neurotrophin system within the brain. We decided to investigate this possibility by modulating the amount of dietary cholesterol given to apoE-knockout (apoE-KO) and wild-type (WT) mice, and examining the mRNA expression of various neurotrophin ligands and receptors in their hippocampal formations. Groups of eight-week-old apoE-KO and WT mice were fed a diet containing either "high" (HCD) or "normal" (ND) levels of cholesterol for a period of 12 weeks. We found that high dietary cholesterol intake elevated BDNF mRNA expression in both apoE-KO and WT mice and TrkB mRNA expression in apoE-KO animals. On the other hand, NGF and TrkA mRNA levels remained unchanged irrespective of both diet and mouse type. These findings indicate that altered cholesterol metabolism induced by HCD ingestion combined with apoE deficiency can elicit a differential response in the various neurotrophin ligand/receptor systems in the mouse hippocampus. Whether such changes can lead to neural degeneration, and the mechanisms that may be involved in this, awaits further research.
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Affiliation(s)
- Zhi-Yu Wang
- Scientific Research Centre, Hebei Medical University Fourth Hospital, Shijiazhuang, Hebei 050011, China
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Beard RS, Bearden SE. Vascular complications of cystathionine β-synthase deficiency: future directions for homocysteine-to-hydrogen sulfide research. Am J Physiol Heart Circ Physiol 2011; 300:H13-26. [PMID: 20971760 PMCID: PMC3023265 DOI: 10.1152/ajpheart.00598.2010] [Citation(s) in RCA: 85] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 06/18/2010] [Accepted: 10/20/2010] [Indexed: 12/19/2022]
Abstract
Homocysteine (Hcy), a cardiovascular and neurovascular disease risk factor, is converted to hydrogen sulfide (H(2)S) through the transsulfuration pathway. H(2)S has attracted considerable attention in recent years for many positive effects on vascular health and homeostasis. Cystathionine β-synthase (CBS) is the first, and rate-limiting, enzyme in the transsulfuration pathway. Mutations in the CBS gene decrease enzymatic activity, which increases the plasma Hcy concentration, a condition called hyperhomocysteinemia (HHcy). Animal models of CBS deficiency have provided invaluable insights into the pathological effects of transsulfuration impairment and of both mild and severe HHcy. However, studies have also highlighted the complexity of HHcy and the need to explore the specific details of Hcy metabolism in addition to Hcy levels per se. There has been a relative paucity of work addressing the dysfunctional H(2)S production in CBS deficiency that may contribute to, or even create, HHcy-associated pathologies. Experiments using CBS knockout mice, both homozygous (-/-) and heterozygous (+/-), have provided 15 years of new knowledge and are the focus of this review. These murine models present the opportunity to study a specific mechanism for HHcy that matches one of the etiologies in many human patients. Therefore, the goal of this review was to integrate and highlight the critical information gained thus far from models of CBS deficiency and draw attention to critical gaps in knowledge, with particular emphasis on the modulation of H(2)S metabolism. We include findings from human and animal studies to identify important opportunities for future investigation that should be aimed at generating new basic and clinical understanding of the role of CBS and transsulfuration in cardiovascular and neurovascular disease.
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Affiliation(s)
- Richard S Beard
- Department of Biological Sciences, Idaho State University, Pocatello, Idaho ID 83209-8007, USA
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Okonkwo OC, Alosco ML, Jerskey BA, Sweet LH, Ott BR, Tremont G. Cerebral atrophy, apolipoprotein E varepsilon4, and rate of decline in everyday function among patients with amnestic mild cognitive impairment. Alzheimers Dement 2010; 6:404-11. [PMID: 20813341 DOI: 10.1016/j.jalz.2010.02.003] [Citation(s) in RCA: 40] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2009] [Revised: 02/20/2010] [Accepted: 02/22/2010] [Indexed: 12/25/2022]
Abstract
BACKGROUND Patients with amnestic mild cognitive impairment (MCI) demonstrate decline in everyday function. In this study, we investigated whether whole brain atrophy and apolipoprotein E (APOE) genotype are associated with the rate of functional decline in MCI. METHODS Participants were 164 healthy controls, 258 MCI patients, and 103 patients with mild Alzheimer's disease (AD), enrolled in the Alzheimer's Disease Neuroimaging Initiative. They underwent brain MRI scans, APOE genotyping, and completed up to six biannual Functional Activities Questionnaire (FAQ) assessments. Random effects regressions were used to examine trajectories of decline in FAQ across diagnostic groups, and to test the effects of ventricle-to-brain ratio (VBR) and APOE genotype on FAQ decline among MCI patients. RESULTS Rate of decline in FAQ among MCI patients was intermediate between that of controls and mild AD patients. Patients with MCI who converted to mild AD declined faster than those who remained stable. Among MCI patients, increased VBR and possession of any APOE varepsilon4 allele were associated with faster rate of decline in FAQ. In addition, there was a significant VBR by APOE varepsilon4 interaction such that patients who were APOE varepsilon4 positive and had increased atrophy experienced the fastest decline in FAQ. CONCLUSIONS Functional decline occurs in MCI, particularly among patients who progress to mild AD. Brain atrophy and APOE varepsilon4 positivity are associated with such declines, and patients who have elevated brain atrophy and are APOE varepsilon4 positive are at greatest risk of functional degradation. These findings highlight the value of genetic and volumetric MRI information as predictors of functional decline, and thus disease progression, in MCI.
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Affiliation(s)
- Ozioma C Okonkwo
- Department of Neurology, Johns Hopkins University School of Medicine, Baltimore, MD, USA.
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Rohn TT, Wirawan E, Brown RJ, Harris JR, Masliah E, Vandenabeele P. Depletion of Beclin-1 due to proteolytic cleavage by caspases in the Alzheimer's disease brain. Neurobiol Dis 2010; 43:68-78. [PMID: 21081164 DOI: 10.1016/j.nbd.2010.11.003] [Citation(s) in RCA: 118] [Impact Index Per Article: 8.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/28/2010] [Revised: 11/03/2010] [Accepted: 11/09/2010] [Indexed: 01/07/2023] Open
Abstract
The Beclin-1 protein is essential for the initiation of autophagy, and recent studies suggest this function may be compromised in Alzheimer's disease (AD). In addition, in vitro studies have supported a loss of function of Beclin-1 due to proteolytic modification by caspases. In the present study, we examined whether caspase-cleavage of Beclin-1 occurs in the AD brain by designing a site-directed caspase-cleavage antibody based upon a known cleavage site within the protein at position D149. We confirmed that Beclin-1 is an excellent substrate for caspase-3 and demonstrates cleavage led to the formation of a 35-kDa C-terminal fragment labeled by our novel antibody following Western blot analysis. Application of this antibody termed Beclin-1 caspase-cleavage product antibody or BeclinCCP in frontal cortex tissue sections revealed strong immunolabeling within astrocytes that localized with plaque regions and along blood vessels in all AD cases examined. In addition, weaker, more variable BeclinCCP labeling was also observed within neurofibrillary tangles that colocalized with the early tau conformational marker, MC-1 as well as the late tangle marker, PHF-1. Collectively, these data support a depletion of Beclin-1 in AD following caspase-cleavage. This article is part of a Special Issue entitled "Autophagy and protein degradation in neurological diseases."
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Affiliation(s)
- Troy T Rohn
- Department of Biological Sciences, Science/Nursing Building, Room 228, Boise State University, Boise, ID 83725, USA.
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