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Anisetti B, Stewart MW, Eggenberger ER, Shourav MMI, Youssef H, Elkhair A, Ertekin-Taner N, Meschia JF, Lin MP. Age-related macular degeneration is associated with probable cerebral amyloid angiopathy: A case-control study. J Stroke Cerebrovasc Dis 2023; 32:107244. [PMID: 37422928 DOI: 10.1016/j.jstrokecerebrovasdis.2023.107244] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/05/2023] [Revised: 06/14/2023] [Accepted: 07/04/2023] [Indexed: 07/11/2023] Open
Abstract
BACKGROUND Age-related macular degeneration (AMD) is a common retinal degenerative disorder among older individuals. Amyloid deposits, a hallmark of cerebral amyloid angiopathy (CAA), may be involved in the pathogenesis of AMD. Since amyloid deposits may contribute to the development of both AMD and CAA, we hypothesized that patients with AMD have a higher prevalence of CAA. OBJECTIVE To compare the prevalence of CAA in patients with or without AMD matched for age. METHODS We conducted a cross-sectional, 1:1 age-matched, case-control study of patients ≥40 years of age at the Mayo Clinic who had undergone both retinal optical coherence tomography and brain MRI from 2011 to 2015. Primary dependent variables were probable CAA, superficial siderosis, and lobar and deep cerebral microbleeds (CMBs). The relationship between AMD and CAA was assessed using multivariable logistic regression and was compared across AMD severity (none vs early vs late AMD). RESULTS Our analysis included 256 age-matched pairs (AMD 126, no AMD 130). Of those with AMD, 79 (30.9%) had early AMD and 47 (19.4%) had late AMD. The mean age was 75±9 years, and there was no significant difference in vascular risk factors between groups. Patients with AMD had a higher prevalence of CAA (16.7% vs 10.0%, p=0.116) and superficial siderosis (15.1% vs 6.2%, p=0.020), but not deep CMB (5.2% vs 6.2%, p=0.426), compared to those without AMD. After adjusting for covariates, having late AMD was associated with increased odds of CAA (OR 2.83, 95% CI 1.10-7.27, p=0.031) and superficial siderosis (OR 3.40, 95%CI 1.20-9.65, p=0.022), but not deep CMB (OR 0.7, 95%CI 0.14-3.51, p=0.669). CONCLUSIONS AMD was associated with CAA and superficial siderosis but not deep CMB, consistent with the hypothesis that amyloid deposits play a role in the development of AMD. Prospective studies are needed to determine if features of AMD may serve as biomarkers for the early diagnosis of CAA.
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Affiliation(s)
- Bhrugun Anisetti
- Department of Neurology, Mayo Clinic, 4500 San Pablo Rd., Jacksonville, FL 32224, United States
| | - Michael W Stewart
- Department of Ophthalmology, Mayo Clinic, Jacksonville, FL, United States
| | - Eric R Eggenberger
- Department of Neurology, Mayo Clinic, 4500 San Pablo Rd., Jacksonville, FL 32224, United States; Department of Ophthalmology, Mayo Clinic, Jacksonville, FL, United States
| | - Md Manjurul I Shourav
- Department of Neurology, Mayo Clinic, 4500 San Pablo Rd., Jacksonville, FL 32224, United States
| | - Hossam Youssef
- Department of Neurology, Mayo Clinic, 4500 San Pablo Rd., Jacksonville, FL 32224, United States
| | - Ahamed Elkhair
- Department of Neurology, Mayo Clinic, 4500 San Pablo Rd., Jacksonville, FL 32224, United States
| | - Nilufer Ertekin-Taner
- Department of Neurology, Mayo Clinic, 4500 San Pablo Rd., Jacksonville, FL 32224, United States
| | - James F Meschia
- Department of Neurology, Mayo Clinic, 4500 San Pablo Rd., Jacksonville, FL 32224, United States
| | - Michelle P Lin
- Department of Neurology, Mayo Clinic, 4500 San Pablo Rd., Jacksonville, FL 32224, United States.
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Somin S, Kulasiri D, Samarasinghe S. Alleviating the unwanted effects of oxidative stress on Aβ clearance: a review of related concepts and strategies for the development of computational modelling. Transl Neurodegener 2023; 12:11. [PMID: 36907887 PMCID: PMC10009979 DOI: 10.1186/s40035-023-00344-2] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/07/2022] [Accepted: 02/21/2023] [Indexed: 03/14/2023] Open
Abstract
Treatment for Alzheimer's disease (AD) can be more effective in the early stages. Although we do not completely understand the aetiology of the early stages of AD, potential pathological factors (amyloid beta [Aβ] and tau) and other co-factors have been identified as causes of AD, which may indicate some of the mechanism at work in the early stages of AD. Today, one of the primary techniques used to help delay or prevent AD in the early stages involves alleviating the unwanted effects of oxidative stress on Aβ clearance. 4-Hydroxynonenal (HNE), a product of lipid peroxidation caused by oxidative stress, plays a key role in the adduction of the degrading proteases. This HNE employs a mechanism which decreases catalytic activity. This process ultimately impairs Aβ clearance. The degradation of HNE-modified proteins helps to alleviate the unwanted effects of oxidative stress. Having a clear understanding of the mechanisms associated with the degradation of the HNE-modified proteins is essential for the development of strategies and for alleviating the unwanted effects of oxidative stress. The strategies which could be employed to decrease the effects of oxidative stress include enhancing antioxidant activity, as well as the use of nanozymes and/or specific inhibitors. One area which shows promise in reducing oxidative stress is protein design. However, more research is needed to improve the effectiveness and accuracy of this technique. This paper discusses the interplay of potential pathological factors and AD. In particular, it focuses on the effect of oxidative stress on the expression of the Aβ-degrading proteases through adduction of the degrading proteases caused by HNE. The paper also elucidates other strategies that can be used to alleviate the unwanted effects of oxidative stress on Aβ clearance. To improve the effectiveness and accuracy of protein design, we explain the application of quantum mechanical/molecular mechanical approach.
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Affiliation(s)
- Sarawoot Somin
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, 7647, New Zealand.,Department of Wine, Food and Molecular Biosciences, Lincoln University, Christchurch, 7647, New Zealand
| | - Don Kulasiri
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, 7647, New Zealand. .,Department of Wine, Food and Molecular Biosciences, Lincoln University, Christchurch, 7647, New Zealand.
| | - Sandhya Samarasinghe
- Centre for Advanced Computational Solutions (C-fACS), Lincoln University, Christchurch, 7647, New Zealand
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3
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Blasiak J, Sobczuk P, Pawlowska E, Kaarniranta K. Interplay between aging and other factors of the pathogenesis of age-related macular degeneration. Ageing Res Rev 2022; 81:101735. [PMID: 36113764 DOI: 10.1016/j.arr.2022.101735] [Citation(s) in RCA: 14] [Impact Index Per Article: 7.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/24/2022] [Revised: 08/03/2022] [Accepted: 09/12/2022] [Indexed: 01/31/2023]
Abstract
Age-related macular degeneration (AMD) is a complex eye disease with the retina as the target tissue and aging as per definition the most serious risk factor. However, the retina contains over 60 kinds of cells that form different structures, including the neuroretina and retinal pigment epithelium (RPE) which can age at different rates. Other established or putative AMD risk factors can differentially affect the neuroretina and RPE and can differently interplay with aging of these structures. The occurrence of β-amyloid plaques and increased levels of cholesterol in AMD retinas suggest that AMD may be a syndrome of accelerated brain aging. Therefore, the question about the real meaning of age in AMD is justified. In this review we present and update information on how aging may interplay with some aspects of AMD pathogenesis, such as oxidative stress, amyloid beta formation, circadian rhythm, metabolic aging and cellular senescence. Also, we show how this interplay can be specific for photoreceptors, microglia cells and RPE cells as well as in Bruch's membrane and the choroid. Therefore, the process of aging may differentially affect different retinal structures. As an accurate quantification of biological aging is important for risk stratification and early intervention for age-related diseases, the determination how photoreceptors, microglial and RPE cells age in AMD may be helpful for a precise diagnosis and treatment of this largely untreatable disease.
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Affiliation(s)
- Janusz Blasiak
- Department of Molecular Genetics, University of Lodz, Pomorska 141/143, 90-236, Lodz, Poland.
| | - Piotr Sobczuk
- Emergency Medicine and Disaster Medicine Department, Medical University of Lodz, Pomorska 251, 92-209 Lodz, Poland; Department of Orthopaedics and Traumatology, Polish Mothers' Memorial Hospital - Research Institute, Rzgowska 281, 93-338 Lodz, Poland
| | - Elzbieta Pawlowska
- Department of Pediatric Dentistry, Medical University of Lodz, Pomorska 251, 92-216 Lodz, Poland
| | - Kai Kaarniranta
- Department of Ophthalmology, Institute of Clinical Medicine, University of Eastern Finland, P.O. Box 1627, FI-70211, Kuopio, Finland; Department of Ophthalmology, Kuopio University Hospital, KYS, P.O. Box 100, FI-70029 Finland
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4
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Oz M, Lorke DE, Kabbani N. A comprehensive guide to the pharmacologic regulation of angiotensin converting enzyme 2 (ACE2), the SARS-CoV-2 entry receptor. Pharmacol Ther 2021; 221:107750. [PMID: 33275999 PMCID: PMC7854082 DOI: 10.1016/j.pharmthera.2020.107750] [Citation(s) in RCA: 27] [Impact Index Per Article: 9.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2020] [Revised: 11/18/2020] [Accepted: 11/19/2020] [Indexed: 02/06/2023]
Abstract
The recent emergence of coronavirus disease-2019 (COVID-19) as a global pandemic has prompted scientists to address an urgent need for defining mechanisms of disease pathology and treatment. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), the causative agent for COVID-19, employs angiotensin converting enzyme 2 (ACE2) as its primary target for cell surface attachment and likely entry into the host cell. Thus, understanding factors that may regulate the expression and function of ACE2 in the healthy and diseased body is critical for clinical intervention. Over 66% of all adults in the United States are currently using a prescription drug and while earlier findings have focused on possible upregulation of ACE2 expression through the use of renin angiotensin system (RAS) inhibitors, mounting evidence suggests that various other widely administered drugs used in the treatment of hypertension, heart failure, diabetes mellitus, hyperlipidemias, coagulation disorders, and pulmonary disease may also present a varied risk for COVID-19. Specifically, we summarize mechanisms on how heparin, statins, steroids and phytochemicals, besides their established therapeutic effects, may also interfere with SARS-CoV-2 viral entry into cells. We also describe evidence on the effect of several vitamins, phytochemicals, and naturally occurring compounds on ACE2 expression and activity in various tissues and disease models. This comprehensive review aims to provide a timely compendium on the potential impact of commonly prescribed drugs and pharmacologically active compounds on COVID-19 pathology and risk through regulation of ACE2 and RAS signaling.
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Key Words
- adam17, a disintegrin and metalloprotease 17
- ace, angiotensin i converting enzyme
- ace-inh., angiotensin i converting enzyme inhibitor
- ampk, amp-activated protein kinase
- ang-ii, angiotensin ii
- arb, angiotensin ii type 1-receptor blocker
- ards, acute respiratory distress syndrome
- at1-r, angiotensin ii type 1-receptor
- βarb, β-adrenergic receptor blockers
- bk, bradykinin
- ccb, calcium channel blockers
- ch25h, cholesterol-25-hydroxylase
- copd, chronic obstructive lung disease
- cox, cyclooxygenase
- covid-19, coronavirus disease-2019
- dabk, [des-arg9]-bradykinin
- erk, extracellular signal-regulated kinase
- 25hc, 25-hydroxycholesterol
- hs, heparan sulfate
- hspg, heparan sulfate proteoglycan
- ibd, inflammatory bowel disease
- map, mitogen-activated protein
- mers, middle east respiratory syndrome
- mrb, mineralocorticoid receptor blocker
- nos, nitric oxide synthase
- nsaid, non-steroid anti-inflammatory drug
- ras, renin-angiotensin system
- sars-cov, severe acute respiratory syndrome coronavirus
- sh, spontaneously hypertensive
- s protein, spike protein
- sirt1, sirtuin 1
- t2dm, type 2 diabetes mellitus
- tcm, traditional chinese medicine
- tmprss2, transmembrane protease, serine 2
- tnf, tumor necrosis factor
- ufh, unfractionated heparin
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Affiliation(s)
- Murat Oz
- Department of Pharmacology and Therapeutics, Faculty of Pharmacy, Kuwait University, Safat 13110, Kuwait.
| | - Dietrich Ernst Lorke
- Department of Anatomy and Cellular Biology, College of Medicine and Health Sciences, Khalifa University, Abu Dhabi, United Arab Emirates; Center for Biotechnology, Khalifa University of Science and Technology, Abu Dhabi, United Arab Emirates
| | - Nadine Kabbani
- School of Systems Biology, George Mason University, Fairfax, VA 22030, USA
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Chibhabha F, Yang Y, Ying K, Jia F, Zhang Q, Ullah S, Liang Z, Xie M, Li F. Non-invasive optical imaging of retinal Aβ plaques using curcumin loaded polymeric micelles in APP swe/PS1 ΔE9 transgenic mice for the diagnosis of Alzheimer's disease. J Mater Chem B 2021; 8:7438-7452. [PMID: 32662804 DOI: 10.1039/d0tb01101k] [Citation(s) in RCA: 24] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Alzheimer's disease (AD) is a neurodegenerative disease clinically characterized by impaired memory and progressive cognitive decline. Despite the advances in AD research, an effective method to timely diagnose AD has remained elusive, and until now, most AD patients receive the available symptomatic treatments late. Although the pathological hallmarks of AD have been traditionally described in the brain, recent studies have shown similar pathological changes in the retina which is developmentally an extension of the forebrain. Interestingly, retinal beta-amyloid (Aβ) accumulation preceded that of the brain in a transgenic mouse model of AD. In the quest of finding an early reliable biomarker for AD, researchers have targeted the optical imaging of retinal Aβ plaques as a method of diagnosing AD. One promising polyphenol compound that has found application in this area is curcumin due to its natural binding affinity to Aβ fibrils and oligomers while giving out a strong fluorescence signal. However, the clinical applications of curcumin have been difficult due to problems related to its bioavailability and retention in the body since it is a hydrophobic molecule. To address these limitations, we herein report the development of anionic and water-soluble DSPE-PEG2000 curcumin polymeric micelles (also referred to as curcumin micelles) that can label both brain and retinal Aβ plaques ex vivo. Following their intravitreal injection in the APPswe/PS1ΔE9 transgenic mouse model of AD, green-labeled retinal deposits were optically imaged live using a rodent retinal microscope. Furthermore, these micelles had excellent intraocular biocompatibility, low hemolytic ratio, and were safe for use in two key retinal cell lines (ARPE-19 and 661W cells). Taken together, these findings provide an alternative insight into the optical imaging of Aβ plaques for the diagnosis of AD using the eyes. More importantly, this study can be translated to humans in the future to improve on early diagnosis and timely management of the disease.
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Affiliation(s)
- Fidelis Chibhabha
- Department of Anatomy and Neurobiology, Zhongshan School of Medicine, Sun Yat-sen University, Guangzhou 510080, China.
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Rao H, Jalali JA, Johnston TP, Koulen P. Emerging Roles of Dyslipidemia and Hyperglycemia in Diabetic Retinopathy: Molecular Mechanisms and Clinical Perspectives. Front Endocrinol (Lausanne) 2021; 12:620045. [PMID: 33828528 PMCID: PMC8020813 DOI: 10.3389/fendo.2021.620045] [Citation(s) in RCA: 32] [Impact Index Per Article: 10.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Accepted: 01/25/2021] [Indexed: 12/20/2022] Open
Abstract
Diabetic retinopathy (DR) is a significant cause of vision loss and a research subject that is constantly being explored for new mechanisms of damage and potential therapeutic options. There are many mechanisms and pathways that provide numerous options for therapeutic interventions to halt disease progression. The purpose of the present literature review is to explore both basic science research and clinical research for proposed mechanisms of damage in diabetic retinopathy to understand the role of triglyceride and cholesterol dysmetabolism in DR progression. This review delineates mechanisms of damage secondary to triglyceride and cholesterol dysmetabolism vs. mechanisms secondary to diabetes to add clarity to the pathogenesis behind each proposed mechanism. We then analyze mechanisms utilized by both triglyceride and cholesterol dysmetabolism and diabetes to elucidate the synergistic, additive, and common mechanisms of damage in diabetic retinopathy. Gathering this research adds clarity to the role dyslipidemia has in DR and an evaluation of the current peer-reviewed basic science and clinical evidence provides a basis to discern new potential therapeutic targets.
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Affiliation(s)
- Hussain Rao
- Department of Ophthalmology, School of Medicine, Vision Research Center, University of Missouri – Kansas City, Kansas City, MO, United States
| | - Jonathan A. Jalali
- Department of Ophthalmology, School of Medicine, Vision Research Center, University of Missouri – Kansas City, Kansas City, MO, United States
| | - Thomas P. Johnston
- Department of Ophthalmology, School of Medicine, Vision Research Center, University of Missouri – Kansas City, Kansas City, MO, United States
- Division of Pharmacology and Pharmaceutical Sciences, School of Pharmacy, University of Missouri – Kansas City, Kansas City, MO, United States
| | - Peter Koulen
- Department of Ophthalmology, School of Medicine, Vision Research Center, University of Missouri – Kansas City, Kansas City, MO, United States
- Department of Biomedical Sciences, School of Medicine, University of Missouri – Kansas City, Kansas City, MO, United States
- *Correspondence: Peter Koulen,
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7
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de Dios C, Bartolessis I, Roca-Agujetas V, Barbero-Camps E, Mari M, Morales A, Colell A. Oxidative inactivation of amyloid beta-degrading proteases by cholesterol-enhanced mitochondrial stress. Redox Biol 2019; 26:101283. [PMID: 31376793 PMCID: PMC6675974 DOI: 10.1016/j.redox.2019.101283] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/23/2019] [Revised: 07/15/2019] [Accepted: 07/24/2019] [Indexed: 02/06/2023] Open
Abstract
Familial early-onset forms of Alzheimer's disease (AD) are linked to overproduction of amyloid beta (Aβ) peptides, while decreased clearance of Aβ is the driving force leading to its toxic accumulation in late-onset (sporadic) AD. Oxidative modifications and defective function have been reported in Aβ-degrading proteases such as neprilysin (NEP) and insulin-degrading enzyme (IDE). However, the exact mechanisms that regulate the proteolytic clearance of Aβ and its deficits are largely unknown. We have previously showed that cellular cholesterol loading, by depleting the mitochondrial GSH (mGSH) content, stimulates Αβ-induced mitochondrial oxidative stress and promotes AD-like pathology in APP-PSEN1-SREBF2 mice. Here, using the same AD mouse model we examined whether cholesterol-enhanced mitochondrial oxidative stress affects NEP and IDE function. We found that brain extracts from APP-PSEN1-SREBF2 mice displayed increased presence of oxidatively modified forms of NEP and IDE, associated with impaired enzymatic activities. Both alterations were substantially recovered after an in vivo treatment with the cholesterol-lowering agent 2-hydroxypropyl-β-cyclodextrin. The recovery of the proteolytic activity after treatment was accompanied with a significant reduction of Aβ levels. Supporting these results, cholesterol-enriched SH-SY5Y cells were more sensitive to Aβ-induced impairment of IDE and NEP function in vitro. The rise of cellular cholesterol also stimulated the extracellular release of IDE by an unconventional autophagy-coordinated mechanism. Recovery of depleted pool of mGSH in these cells not only prevented the detrimental effect of Aβ on intracellular AβDPs activities but also had an impact on extracellular IDE levels and function, stimulating the extracellular Aβ degrading activity. Therefore, changes in brain cholesterol levels by modifying the mGSH content would play a key role in IDE and NEP-mediated proteolytic elimination of Aβ peptides and AD progression. Cholesterol regulates IDE and NEP by enhancing the detrimental effect of Aβ on their proteolytic activities. Cholesterol-mediated mitochondrial GSH depletion is responsible for the oxidative impairment of IDE and NEP. High cholesterol levels induce the release of inactive IDE through secretory autophagy. A rise in cellular cholesterol affects the extracellular Aβ degradation, favoring oligomers formation. Cholesterol lowering compounds and antioxidant therapy restore IDE and NEP activity.
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Affiliation(s)
- Cristina de Dios
- Department of Cell Death and Proliferation, Institut D'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain; Departament de Biomedicina, Facultat de Medicina, Universitat de Barcelona, Barcelona, Spain; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Isabel Bartolessis
- Department of Cell Death and Proliferation, Institut D'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
| | - Vicente Roca-Agujetas
- Department of Cell Death and Proliferation, Institut D'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Spain
| | - Elisabet Barbero-Camps
- Department of Cell Death and Proliferation, Institut D'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
| | - Montserrat Mari
- Department of Cell Death and Proliferation, Institut D'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
| | - Albert Morales
- Department of Cell Death and Proliferation, Institut D'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain
| | - Anna Colell
- Department of Cell Death and Proliferation, Institut D'Investigacions Biomèdiques de Barcelona, Consejo Superior de Investigaciones Científicas (CSIC), Institut D'Investigacions Biomèdiques August Pi I Sunyer (IDIBAPS), Barcelona, Spain; Centro de Investigación Biomédica en Red Sobre Enfermedades Neurodegenerativas (CIBERNED), Spain.
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Wang C, Shou Y, Pan J, Du Y, Liu C, Wang H. The relationship between cholesterol level and Alzheimer’s disease-associated APP proteolysis/Aβ metabolism. Nutr Neurosci 2018; 22:453-463. [DOI: 10.1080/1028415x.2017.1416942] [Citation(s) in RCA: 15] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Chaoqun Wang
- School of Medicine, Hangzhou Normal University, Hangzhou, People’s Republic of China
| | - Yikai Shou
- School of Medicine, Hangzhou Normal University, Hangzhou, People’s Republic of China
| | - Jie Pan
- Department of Endocrinology and Metabolism, 2nd Affiliated Hospital, School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China
- Institute of Gastroenterology, Zhejiang University, Hangzhou, People’s Republic of China
| | - Yue Du
- School of Medicine, Zhejiang University, Hangzhou, People’s Republic of China
| | - Cuiqing Liu
- College of Basic Medicine, Zhejiang Chinese Medical University, Hangzhou, People’s Republic of China
| | - Huanhuan Wang
- School of Medicine, Hangzhou Normal University, Hangzhou, People’s Republic of China
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Beta-amyloid sequelae in the eye: a critical review on its diagnostic significance and clinical relevance in Alzheimer's disease. Mol Psychiatry 2017; 22:353-363. [PMID: 28093567 DOI: 10.1038/mp.2016.251] [Citation(s) in RCA: 43] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/29/2016] [Revised: 10/31/2016] [Accepted: 11/22/2016] [Indexed: 01/14/2023]
Abstract
Alzheimer's disease (AD) is a progressive and fatal neurodegenerative disorder. There is no test for its definitive diagnosis in routine clinical practice. Although phase III clinical trials have failed, only symptomatic treatment is currently available; a possible reason for these failed trials is that intervention commenced at an advanced stage of the disease. The hallmarks of an AD brain include plaques comprising of extracellular beta-amyloid (Aβ) protein aggregates and intracellular hyperphosphorylated neurofibrillary tangles of tau. Research into the preclinical diagnosis of AD has provided considerable evidence regarding early neuropathological changes using brain Aβ imaging and the cerebrospinal fluid biomarkers, Aβ and tau. Both these approaches have limitations that are expensive, invasive or time consuming and thus preclude them from screening at-risk population. Recent studies have demonstrated the presence of Aβ plaques in the eyes of AD subjects, which is positively associated with their brain Aβ burden. Thus ocular biomarkers point to a potential avenue for an earlier, relatively low-cost diagnosis in order for therapeutic interventions to be effective. Here we review the literature that spans the investigation for the presence of Aβ in aging eyes and the significance of its deposition in relation to AD pathology. We discuss clinical studies investigating in vivo imaging of Aβ in the eye and its association with brain Aβ burden and therapies that target ocular Aβ. Finally, we focus on the need to characterize AD-specific retinal Aβ to differentiate Aβ found in some eye diseases. Based on the current evidence, we conclude that integration of ocular biomarkers that can correctly predict brain Aβ burden would have an important role as a non-invasive, yet economical surrogate marker in the diagnostic process of AD.
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Zhao Y, Hou D, Feng X, Lin F, Luo J. Role of ABC transporters in the pathology of Alzheimer’s disease. Rev Neurosci 2017; 28:155-159. [PMID: 27997355 DOI: 10.1515/revneuro-2016-0060] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/18/2016] [Accepted: 10/01/2016] [Indexed: 12/25/2022]
Abstract
AbstractThe ATP-binding cassette (ABC) transporter superfamily is a large family of proteins that transport specific molecules across membranes. These proteins are associated with both cholesterol metabolism and Alzheimer’s disease (AD). Cholesterol homeostasis has a key role in AD, and ABC transporters are important mediators of lipid transportation. Emerging evidence suggests that decreased expression and hypofunction of ABC transporters are crucial to the occurrence and development of AD. In the present article, we review the current knowledge regarding ABC transporters and speculate on their role in the pathogenesis of AD.
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Affiliation(s)
- Yan Zhao
- 1Department of Neurology, The Third Xiangya Hospital, Central South University, 138 Tongzipo Road, Changsha HN 410013, China
| | - Deren Hou
- 1Department of Neurology, The Third Xiangya Hospital, Central South University, 138 Tongzipo Road, Changsha HN 410013, China
| | - Xialu Feng
- 1Department of Neurology, The Third Xiangya Hospital, Central South University, 138 Tongzipo Road, Changsha HN 410013, China
| | - Fangbo Lin
- 1Department of Neurology, The Third Xiangya Hospital, Central South University, 138 Tongzipo Road, Changsha HN 410013, China
| | - Jing Luo
- 1Department of Neurology, The Third Xiangya Hospital, Central South University, 138 Tongzipo Road, Changsha HN 410013, China
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Chen L, Ou S, Zhou L, Tang H, Xu J, Guo K. Formononetin attenuates Aβ25-35-induced cytotoxicity in HT22 cells via PI3K/Akt signaling and non-amyloidogenic cleavage of APP. Neurosci Lett 2017; 639:36-42. [DOI: 10.1016/j.neulet.2016.12.064] [Citation(s) in RCA: 19] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/01/2016] [Revised: 12/23/2016] [Accepted: 12/24/2016] [Indexed: 10/20/2022]
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12
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Lynn SA, Keeling E, Munday R, Gabha G, Griffiths H, Lotery AJ, Ratnayaka JA. The complexities underlying age-related macular degeneration: could amyloid beta play an important role? Neural Regen Res 2017; 12:538-548. [PMID: 28553324 PMCID: PMC5436342 DOI: 10.4103/1673-5374.205083] [Citation(s) in RCA: 27] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022] Open
Abstract
Age-related macular degeneration (AMD) causes irreversible loss of central vision for which there is no effective treatment. Incipient pathology is thought to occur in the retina for many years before AMD manifests from midlife onwards to affect a large proportion of the elderly. Although genetic as well as non-genetic/environmental risks are recognized, its complex aetiology makes it difficult to identify susceptibility, or indeed what type of AMD develops or how quickly it progresses in different individuals. Here we summarize the literature describing how the Alzheimer's-linked amyloid beta (Aβ) group of misfolding proteins accumulate in the retina. The discovery of this key driver of Alzheimer's disease in the senescent retina was unexpected and surprising, enabling an altogether different perspective of AMD. We argue that Aβ fundamentally differs from other substances which accumulate in the ageing retina, and discuss our latest findings from a mouse model in which physiological amounts of Aβ were subretinally-injected to recapitulate salient features of early AMD within a short period. Our discoveries as well as those of others suggest the pattern of Aβ accumulation and pathology in donor aged/AMD tissues are closely reproduced in mice, including late-stage AMD phenotypes, which makes them highly attractive to study dynamic aspects of Aβ-mediated retinopathy. Furthermore, we discuss our findings revealing how Aβ behaves at single-cell resolution, and consider the long-term implications for neuroretinal function. We propose Aβ as a key element in switching to a diseased retinal phenotype, which is now being used as a biomarker for late-stage AMD.
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Affiliation(s)
- Savannah A Lynn
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Rosie Munday
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Gagandeep Gabha
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Helen Griffiths
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom.,Eye Unit, University Southampton NHS Trust, Southampton, United Kingdom
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, Southampton, United Kingdom
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Taylor-Walker G, Lynn SA, Keeling E, Munday R, Johnston DA, Page A, Scott JA, Goverdhan S, Lotery AJ, Ratnayaka JA. The Alzheimer's-related amyloid beta peptide is internalised by R28 neuroretinal cells and disrupts the microtubule associated protein 2 (MAP-2). Exp Eye Res 2016; 153:110-121. [PMID: 27751744 PMCID: PMC5131630 DOI: 10.1016/j.exer.2016.10.013] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2016] [Revised: 09/12/2016] [Accepted: 10/11/2016] [Indexed: 11/15/2022]
Abstract
Age-related Macular Degeneration (AMD) is a common, irreversible blinding condition that leads to the loss of central vision. AMD has a complex aetiology with both genetic as well as environmental risks factors, and share many similarities with Alzheimer's disease. Recent findings have contributed significantly to unravelling its genetic architecture that is yet to be matched by molecular insights. Studies are made more challenging by observations that aged and AMD retinas accumulate the highly pathogenic Alzheimer's-related Amyloid beta (Aβ) group of peptides, for which there appears to be no clear genetic basis. Analyses of human donor and animal eyes have identified retinal Aβ aggregates in retinal ganglion cells (RGC), the inner nuclear layer, photoreceptors as well as the retinal pigment epithelium. Aβ is also a major drusen constituent; found correlated with elevated drusen-load and age, with a propensity to aggregate in retinas of advanced AMD. Despite this evidence, how such a potent driver of neurodegeneration might impair the neuroretina remains incompletely understood, and studies into this important aspect of retinopathy remains limited. In order to address this we exploited R28 rat retinal cells which due to its heterogeneous nature, offers diverse neuroretinal cell-types in which to study the molecular pathology of Aβ. R28 cells are also unaffected by problems associated with the commonly used RGC-5 immortalised cell-line, thus providing a well-established model in which to study dynamic Aβ effects at single-cell resolution. Our findings show that R28 cells express key neuronal markers calbindin, protein kinase C and the microtubule associated protein-2 (MAP-2) by confocal immunofluorescence which has not been shown before, but also calretinin which has not been reported previously. For the first time, we reveal that retinal neurons rapidly internalised Aβ1-42, the most cytotoxic and aggregate-prone amongst the Aβ family. Furthermore, exposure to physiological amounts of Aβ1-42 for 24 h correlated with impairment to neuronal MAP-2, a cytoskeletal protein which regulates microtubule dynamics in axons and dendrites. Disruption to MAP-2 was transient, and had recovered by 48 h, although internalised Aβ persisted as discrete puncta for as long as 72 h. To assess whether Aβ could realistically localise to living retinas to mediate such effects, we subretinally injected nanomolar levels of oligomeric Aβ1-42 into wildtype mice. Confocal microscopy revealed the presence of focal Aβ deposits in RGC, the inner nuclear and the outer plexiform layers 8 days later, recapitulating naturally-occurring patterns of Aβ aggregation in aged retinas. Our novel findings describe how retinal neurons internalise Aβ to transiently impair MAP-2 in a hitherto unreported manner. MAP-2 dysfunction is reported in AMD retinas, and is thought to be involved in remodelling and plasticity of post-mitotic neurons. Our insights suggest a molecular pathway by which this could occur in the senescent eye leading to complex diseases such as AMD. Molecular basis of complex retinopathies such as AMD is incompletely understood. The Alzheimer's-related Aβ peptides are rapidly internalised by retinal neurons. Internalised Aβ is retained within neurons and transiently impairs MAP-2. Subretinally injected Aβ mimics its naturally-occurring distribution in aged retinas.
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Affiliation(s)
- George Taylor-Walker
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Savannah A Lynn
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Eloise Keeling
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Rosie Munday
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - David A Johnston
- Biomedical Imaging Unit, University of Southampton, SGH, MP12, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Anton Page
- Biomedical Imaging Unit, University of Southampton, SGH, MP12, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Jennifer A Scott
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Srini Goverdhan
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom
| | - Andrew J Lotery
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom; Eye Unit, University Southampton NHS Trust, Southampton, SO16 6YD, United Kingdom
| | - J Arjuna Ratnayaka
- Clinical and Experimental Sciences, Faculty of Medicine, University of Southampton, SGH, MP806, Tremona Road, Southampton, SO16 6YD, United Kingdom.
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Ratnayaka JA, Serpell LC, Lotery AJ. Dementia of the eye: the role of amyloid beta in retinal degeneration. Eye (Lond) 2015; 29:1013-26. [PMID: 26088679 PMCID: PMC4541342 DOI: 10.1038/eye.2015.100] [Citation(s) in RCA: 116] [Impact Index Per Article: 12.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/27/2015] [Accepted: 04/23/2015] [Indexed: 11/09/2022] Open
Abstract
Age-related macular degeneration (AMD) is one of the most common causes of irreversible blindness affecting nearly 50 million individuals globally. The disease is characterised by progressive loss of central vision, which has significant implications for quality of life concerns in an increasingly ageing population. AMD pathology manifests in the macula, a specialised region of the retina, which is responsible for central vision and perception of fine details. The underlying pathology of this complex degenerative disease is incompletely understood but includes both genetic as well as epigenetic risk factors. The recent discovery that amyloid beta (Aβ), a highly toxic and aggregate-prone family of peptides, is elevated in the ageing retina and is associated with AMD has opened up new perspectives on the aetiology of this debilitating blinding disease. Multiple studies now link Aβ with key stages of AMD progression, which is both exciting and potentially insightful, as this identifies a well-established toxic agent that aggressively targets cells in degenerative brains. Here, we review the most recent findings supporting the hypothesis that Aβ may be a key factor in AMD pathology. We describe how multiple Aβ reservoirs, now reported in the ageing eye, may target the cellular physiology of the retina as well as associated layers, and propose a mechanistic pathway of Aβ-mediated degenerative change leading to AMD.
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Affiliation(s)
- J A Ratnayaka
- Clinical and Experimental Science, Faculty of Medicine, University of Southampton, Southampton, UK
| | - L C Serpell
- School of Life Sciences (Biochemistry, Dementia Research Group), University of Sussex, Brighton, UK
| | - A J Lotery
- Clinical and Experimental Science, Faculty of Medicine, University of Southampton, Southampton, UK
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15
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El-Sayyad HIH, Elmansi AA, Bakr EHM. Hypercholesterolemia-induced ocular disorder: Ameliorating role of phytotherapy. Nutrition 2015; 31:1307-16. [PMID: 26429651 DOI: 10.1016/j.nut.2015.05.013] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/24/2014] [Revised: 05/07/2015] [Accepted: 05/10/2015] [Indexed: 01/03/2023]
Abstract
The ocular region is a complex structure that allows conscious light perception and vision. It is of ecto-mesodermal origin. Cholesterol and polyunsaturated fatty acids are involved in retinal cell function; however, hypercholesterolemia and diabetes impair its function. Retinal damage, neovascularization, and cataracts are the main complications of cholesterol overload. Dietary supplementation of selected plant products can lead to the scavenging of free reactive oxygen species, thereby protecting the ocular regions from the damage of hypercholesterolemia. This review illustrates the dramatic effects of increased cholesterol levels on the ocular regions. The effect of phytotherapy is discussed in relation to the different regions of the eye, including the retina, cornea, and lens.
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Affiliation(s)
- Hassan I H El-Sayyad
- Faculty of Science, Department of Zoology, Mansoura University, Mansoura, Egypt.
| | - Ahmed A Elmansi
- Faculty of Science, Department of Zoology, Mansoura University, Mansoura, Egypt
| | - Eman H M Bakr
- Faculty of Science, Department of Zoology, Mansoura University, Mansoura, Egypt
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16
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Sun JH, Yu JT, Tan L. The Role of Cholesterol Metabolism in Alzheimer’s Disease. Mol Neurobiol 2014; 51:947-65. [DOI: 10.1007/s12035-014-8749-y] [Citation(s) in RCA: 39] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/02/2014] [Accepted: 05/07/2014] [Indexed: 12/25/2022]
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17
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He Y, Zhao H, Su G. Ginsenoside Rg1 decreases neurofibrillary tangles accumulation in retina by regulating activities of neprilysin and PKA in retinal cells of AD mice model. J Mol Neurosci 2013; 52:101-6. [PMID: 24287922 DOI: 10.1007/s12031-013-0173-7] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/14/2013] [Accepted: 11/04/2013] [Indexed: 10/26/2022]
Abstract
Neurofibrillary tangles (NFTs) are the major component of senile plaques in the brains of patients with Alzheimer's disease (AD). However, the mechanism causing NFTs accumulation in AD patients' retina is also elusive. Thus, we investigated the effects of ginsenoside Rg1 on NFTs accumulation in retinal pigment epithelial (RPE) cells isolated form double transgenic APP/PS1 mice model. NFTs amounts in culture supernatants were examined by enzyme-linked immunosorbent assay. Activity and mRNA transcription of enzymes and proteins that regulate NFTs accumulation were examined by activity assay and reverse transcription PCR. The expression of neprilysin (NEP) and neutral endopeptidase (PKA) were detected by western blot assay. Rg1 significantly decreased NFTs accumulation in isolated RPE cells. Activity of NEP was significantly increased, and activity of PKA was significantly decreased in cell lysates of Rg1-feeding APP/PS1 mice compared with non-Rg1-feeding mice. mRNA level of NEP was significantly higher and mRNA level of PKA was significantly lower in cells of Rg1-feeding mice than nonfeeding mice. The phosphorylation of tau at Thr231, Thr205, and Ser396 were significantly decreased in RPE of Rg1-feeding APP/PS1 mice compared with the non-Rg1-feeding mice. Rg1 decreased the NFTs production in RPE cell of APP/PS1 mice by modulating the expression and activity of NEP and PKA, which perform the function through downregulating the phosphorylation of tau protein.
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Affiliation(s)
- Yanhui He
- Department of Ophthalmology, Second Hospital of Jilin University, 218 Ziqiang Street, Changchun, Jilin, 130041, China
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18
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Role of copper and cholesterol association in the neurodegenerative process. Int J Alzheimers Dis 2013; 2013:414817. [PMID: 24288650 PMCID: PMC3830777 DOI: 10.1155/2013/414817] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/07/2013] [Revised: 09/05/2013] [Accepted: 09/05/2013] [Indexed: 01/22/2023] Open
Abstract
Age is one of the main factors involved in the development of neurological illnesses, in particular, Alzheimer, and it is widely held that the rapid aging of the world population is accompanied by a rise in the prevalence and incidence of Alzheimer disease. However, evidence from recent decades indicates that Cu and Cho overload are emerging causative factors in neurodegeneration, a hypothesis that has been partially investigated in experimental models. The link between these two variables and the onset of Alzheimer disease has opened up interesting new possibilities requiring more in-depth analysis. The aim of the present study was therefore to investigate the effect of the association of Cu + Cho (CuCho) as a possible synergistic factor in the development of an Alzheimer-like pathology in Wistar rats. We measured total- and nonceruloplasmin-bound Cu and Cho (free and sterified) contents in plasma and brain zones (cortex and hippocampus), markers of oxidative stress damage, inflammation, and programmed cell death (caspase-3 and calpain isoforms). The ratio beta-amyloid (1-42)/(1-40) was determined in plasma and brain as neurodegenerative biomarker. An evaluation of visuospatial memory (Barnes maze test) was also performed. The results demonstrate the establishment of a prooxidative and proinflammatory environment after CuCho treatment, hallmarked by increased TBARS, protein carbonyls, and nitrite plus nitrate levels in plasma and brain zones (cortex and hippocampus) with a consequent increase in the activity of calpains and no significant changes in caspase-3. A simultaneous increase in the plasma Aβ1-42/Aβ1-40 ratio was found. Furthermore, a slight but noticeable change in visuospatial memory was observed in rats treated with CuCho. We conclude that our model could reflect an initial stage of neurodegeneration in which Cu and Cho interact with one another to exacerbate neurological damage.
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Di Scala C, Troadec JD, Lelièvre C, Garmy N, Fantini J, Chahinian H. Mechanism of cholesterol-assisted oligomeric channel formation by a short Alzheimer β-amyloid peptide. J Neurochem 2013; 128:186-95. [PMID: 23919567 DOI: 10.1111/jnc.12390] [Citation(s) in RCA: 75] [Impact Index Per Article: 6.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/04/2013] [Revised: 07/22/2013] [Accepted: 07/31/2013] [Indexed: 11/29/2022]
Abstract
Alzheimer β-amyloid (Aβ) peptides can self-organize into oligomeric ion channels with high neurotoxicity potential. Cholesterol is believed to play a key role in this process, but the molecular mechanisms linking cholesterol and amyloid channel formation have so far remained elusive. Here, we show that the short Aβ22-35 peptide, which encompasses the cholesterol-binding domain of Aβ, induces a specific increase of Ca(2+) levels in neural cells. This effect is neither observed in calcium-free medium nor in cholesterol-depleted cells, and is inhibited by zinc, a blocker of amyloid channel activity. Double mutations V24G/K28G and N27R/K28R in Aβ22-35 modify cholesterol binding and abrogate channel formation. Molecular dynamic simulations suggest that cholesterol induces a tilted α-helical topology of Aβ22-35. This facilitates the establishment of an inter-peptide hydrogen bond network involving Asn-27 and Lys-28, a key step in the octamerization of Aβ22-35 which proceeds gradually until the formation of a perfect annular channel in a phosphatidylcholine membrane. Overall, these data give mechanistic insights into the role of cholesterol in amyloid channel formation, opening up new therapeutic options for Alzheimer's disease. Aβ22-35 peptide, which encompasses the cholesterol binding domain of Aβ, induces a specific increase of Ca(2+) level in neural cells. Double mutations V24G/K28G and N27R/K28R modify cholesterol binding and abrogate channels formation. Molecular dynamic simulations suggest that cholesterol induces a tilted α-helical peptide topology facilitating the formation of annular octameric channels, as schematically shown in the graphic (with a hydrogen bond shown in green for two vicinal peptides). Overall, the data give insights into the role of cholesterol in amyloid channel formation and open up new therapeutic options for Alzheimer's disease.
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Affiliation(s)
- Coralie Di Scala
- Faculté des Sciences, Aix-Marseille Université, EA4674, Marseille, France
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