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Dhakal S, Macreadie IG. Simvastatin, Its Antimicrobial Activity and Its Prevention of Alzheimer's Disease. Microorganisms 2024; 12:1133. [PMID: 38930515 PMCID: PMC11205914 DOI: 10.3390/microorganisms12061133] [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: 03/28/2024] [Revised: 05/22/2024] [Accepted: 05/29/2024] [Indexed: 06/28/2024] Open
Abstract
Simvastatin, a blockbuster drug for treating hypercholesterolemia, has multifactorial benefits as an antimicrobial agent and plays a preventative role in reducing the incidence of Alzheimer's Disease (AD). Although most of the beneficial effects of simvastatin have been attributed to its ability to reduce cholesterol levels, recent scientific studies have suggested that its benefits are largely due to its pleiotropic effects in targeting other pathways, e.g., by inhibiting protein lipidation. There are certain pleiotropic effects that can be predicted from the inhibition of the mevalonate pathway; however, some of the effects of simvastatin in proteostasis lead to reduced levels of amyloid beta, the key contributor to AD. This review discusses the use of simvastatin as an antimicrobial agent and anti-AD drug.
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Affiliation(s)
- Sudip Dhakal
- Health and Biosecurity, Commonwealth Scientific and Industrial Research Organization (CSIRO), Geelong, VIC 3220, Australia;
| | - Ian G. Macreadie
- School of Science, RMIT University, Bundoora, VIC 3063, Australia
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2
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Clark C, Gholam M, Zullo L, Kerksiek A, Castelao E, von Gunten A, Preisig M, Lütjohann D, Popp J. Plant sterols and cholesterol metabolism are associated with five-year cognitive decline in the elderly population. iScience 2023; 26:106740. [PMID: 37250771 PMCID: PMC10209479 DOI: 10.1016/j.isci.2023.106740] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/30/2022] [Revised: 02/13/2023] [Accepted: 04/20/2023] [Indexed: 05/31/2023] Open
Abstract
Dysregulations in cholesterol metabolism are associated with neurodegenerative and vascular pathologies, and dementia. Diet-derived plant sterols (phytosterols) have cholesterol-lowering, anti-inflammatory, and antioxidant properties and may interfere with neurodegeneration and cognitive decline. Here we performed multivariate analysis in 720 individuals enrolled in a population-based prospective study to determine whether circulating cholesterol precursors and metabolites, triglycerides, and phytosterols, are associated with cognitive impairment and decline in the older population. We report specific dysregulations of endogenous cholesterol synthesis and metabolism, and diet-derived phytosterols, and their changes over time associated with cognitive impairment, and decline in the general population. These findings suggest circulating sterols levels could be considered in risk evaluation and are relevant for the development of strategies to prevent cognitive decline in older people.
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Affiliation(s)
- Christopher Clark
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Lenggstrasse 31, PO Box 363, 8032 Zürich, Switzerland
- Department of Mathematics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Mehdi Gholam
- Department of Mathematics, Ecole Polytechnique Fédérale de Lausanne, Lausanne, Switzerland
| | - Leonardo Zullo
- Old Age Psychiatry, Department of Psychiatry, Lausanne University Hospital, Route de Cery 60, 1008 Prilly, Switzerland
| | - Anja Kerksiek
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Enrique Castelao
- Department of Psychiatry, Center for Research in Psychiatric Epidemiology and Psychopathology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Armin von Gunten
- Old Age Psychiatry, Department of Psychiatry, Lausanne University Hospital, Route de Cery 60, 1008 Prilly, Switzerland
| | - Martin Preisig
- Department of Psychiatry, Center for Research in Psychiatric Epidemiology and Psychopathology, Lausanne University Hospital and University of Lausanne, Lausanne, Switzerland
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Clinical Pharmacology, University Hospital Bonn, Bonn, Germany
| | - Julius Popp
- Department of Psychiatry, Psychotherapy and Psychosomatics, Psychiatric Hospital, University of Zürich, Lenggstrasse 31, PO Box 363, 8032 Zürich, Switzerland
- Old Age Psychiatry, Department of Psychiatry, Lausanne University Hospital, Route de Cery 60, 1008 Prilly, Switzerland
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3
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Lipids in Pathophysiology and Development of the Membrane Lipid Therapy: New Bioactive Lipids. MEMBRANES 2021; 11:membranes11120919. [PMID: 34940418 PMCID: PMC8708953 DOI: 10.3390/membranes11120919] [Citation(s) in RCA: 11] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 10/10/2021] [Revised: 11/16/2021] [Accepted: 11/19/2021] [Indexed: 12/19/2022]
Abstract
Membranes are mainly composed of a lipid bilayer and proteins, constituting a checkpoint for the entry and passage of signals and other molecules. Their composition can be modulated by diet, pathophysiological processes, and nutritional/pharmaceutical interventions. In addition to their use as an energy source, lipids have important structural and functional roles, e.g., fatty acyl moieties in phospholipids have distinct impacts on human health depending on their saturation, carbon length, and isometry. These and other membrane lipids have quite specific effects on the lipid bilayer structure, which regulates the interaction with signaling proteins. Alterations to lipids have been associated with important diseases, and, consequently, normalization of these alterations or regulatory interventions that control membrane lipid composition have therapeutic potential. This approach, termed membrane lipid therapy or membrane lipid replacement, has emerged as a novel technology platform for nutraceutical interventions and drug discovery. Several clinical trials and therapeutic products have validated this technology based on the understanding of membrane structure and function. The present review analyzes the molecular basis of this innovative approach, describing how membrane lipid composition and structure affects protein-lipid interactions, cell signaling, disease, and therapy (e.g., fatigue and cardiovascular, neurodegenerative, tumor, infectious diseases).
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Zhang L, Yang C, Li Y, Niu S, Liang X, Zhang Z, Luo Q, Luo H. Dynamic Changes in the Levels of Amyloid-β 42 Species in the Brain and Periphery of APP/PS1 Mice and Their Significance for Alzheimer's Disease. Front Mol Neurosci 2021; 14:723317. [PMID: 34512259 PMCID: PMC8430227 DOI: 10.3389/fnmol.2021.723317] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2021] [Accepted: 08/09/2021] [Indexed: 11/13/2022] Open
Abstract
Although amyloid-β42 (Aβ42) has been used as one of the core biomarkers for Alzheimer’s disease (AD) diagnosis, the dynamic changes of its different forms in the brain, blood, and even intestines and its correlation with the progression of AD disease remain obscure. Herein, we screened Aβ42-specific preferred antibody pairs 1F12/1F12 and 1F12/2C6 to accurately detect Aβ42 types using sandwich ELISA, including total Aβ42, Aβ42 oligomers (Aβ42Os), and Aβ42 monomers (Aβ42Ms). The levels of Aβ42 species in the brain, blood, and intestines of different aged APP/PS1 mice were quantified to study their correlation with AD progression. Total Aβ42 levels in the blood were not correlated with AD progression, but Aβ42Ms level in the blood of 9-month-old APP/PS1 mice was significantly reduced, and Aβ42Os level in the brain was significantly elevated compared to 3-month-old APP/PS1, demonstrating that the levels of Aβ42Ms and Aβ42Os in the blood and brain were correlated with AD progression. Interestingly, in 9-month-old APP/PS1 mice, the level of Aβ42 in the intestine was higher than that in 3-month-old APP/PS1 mice, indicating that the increased level of Aβ42 in the gastrointestinal organs may also be related to the progression of AD. Meanwhile, changes in the gut microbiota composition of APP/PS1 mice with age were also observed. Therefore, the increase in Aβ derived from intestinal tissues and changes in microbiome composition can be used as a potential early diagnosis tool for AD, and further used as an indicator of drug intervention to reduce brain amyloid.
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Affiliation(s)
- Liding Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Changwen Yang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Yanqing Li
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Shiqi Niu
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Xiaohan Liang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
| | - Zhihong Zhang
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China.,School of Biomedical Engineering, Hainan University, Haikou, China
| | - Qingming Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China.,School of Biomedical Engineering, Hainan University, Haikou, China
| | - Haiming Luo
- Britton Chance Center for Biomedical Photonics, Wuhan National Laboratory for Optoelectronics, Huazhong University of Science and Technology, Wuhan, China.,MoE Key Laboratory for Biomedical Photonics, School of Engineering Sciences, Huazhong University of Science and Technology, Wuhan, China
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5
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Pedrini S, Hone E, Gupta VB, James I, Teimouri E, Bush AI, Rowe CC, Villemagne VL, Ames D, Masters CL, Rainey-Smith S, Verdile G, Sohrabi HR, Raida MR, Wenk MR, Taddei K, Chatterjee P, Martins I, Laws SM, Martins RN. Plasma High Density Lipoprotein Small Subclass is Reduced in Alzheimer's Disease Patients and Correlates with Cognitive Performance. J Alzheimers Dis 2021; 77:733-744. [PMID: 32741823 PMCID: PMC7592676 DOI: 10.3233/jad-200291] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/20/2023]
Abstract
Background: The link between cholesterol and Alzheimer’s disease (AD) has received much attention, as evidence suggests high levels of cholesterol might be an AD risk factor. The carriage of cholesterol and lipids through the body is mediated via lipoproteins, some of which, particularly apolipoprotein E (ApoE), are intimately linked with AD. In humans, high density lipoprotein (HDL) is regarded as a “good” lipid complex due to its ability to enable clearance of excess cholesterol via ‘cholesterol reverse transport’, although its activities in the pathogenesis of AD are poorly understood. There are several subclasses of HDL; these range from the newly formed small HDL, to much larger HDL. Objective: We examined the major subclasses of HDL in healthy controls, mild cognitively impaired, and AD patients who were not taking statins to determine whether there were HDL profile differences between the groups, and whether HDL subclass levels correlated with plasma amyloid-β (Aβ) levels or brain Aβ deposition. Methods: Samples from AIBL cohort were used in this study. HDL subclass levels were assessed by Lipoprint while Aβ1–42 levels were assessed by ELISA. Brain Aβ deposition was assessed by PET scan. Statistical analysis was performed using parametric and non-parametric tests. Results: We found that small HDL subclass is reduced in AD patients and it correlates with cognitive performance while plasma Aβ concentrations do not correlate with lipid profile or HDL subfraction levels. Conclusion: Our data indicate that AD patients exhibit altered plasma HDL profile and that HDL subclasses correlate with cognitive performances.
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Affiliation(s)
- Steve Pedrini
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia.,CRC for Mental Health, Carlton South, Victoria, Australia
| | - Eugene Hone
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia.,CRC for Mental Health, Carlton South, Victoria, Australia
| | - Veer B Gupta
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia.,CRC for Mental Health, Carlton South, Victoria, Australia
| | - Ian James
- Institute for Immunology and Infectious Diseases, Murdoch University, Murdoch, WA, Australia
| | - Elham Teimouri
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia
| | - Ashley I Bush
- CRC for Mental Health, Carlton South, Victoria, Australia.,The Florey Institute, The University of Melbourne, Parkville, Victoria, Australia
| | - Christopher C Rowe
- Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Victoria, Australia
| | - Victor L Villemagne
- Department of Nuclear Medicine and Centre for PET, Austin Health, Heidelberg, Victoria, Australia
| | - David Ames
- National Ageing Research Institute, Parkville, Victoria, Australia.,University of Melbourne Academic unit for Psychiatry of Old Age, St George's Hospital, Kew, Victoria, Australia
| | - Colin L Masters
- The Florey Institute, The University of Melbourne, Parkville, Victoria, Australia
| | | | - Giuseppe Verdile
- School of Biomedical Sciences, Curtin University, Bentley, WA, Australia
| | - Hamid R Sohrabi
- Centre for Healthy Ageing, School of Psychology and Exercise Science, Murdoch University, Murdoch, WA, Australia
| | - Manfred R Raida
- Life Science Institute, Singapore Lipidomics Incubator, National University of Singapore, Singapore
| | - Markus R Wenk
- Department of Biochemistry, Yong Loo Lin School of Medicine, National University of Singapore, Singapore
| | - Kevin Taddei
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia.,CRC for Mental Health, Carlton South, Victoria, Australia
| | - Pratishtha Chatterjee
- Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia
| | - Ian Martins
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia.,CRC for Mental Health, Carlton South, Victoria, Australia
| | - Simon M Laws
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia.,CRC for Mental Health, Carlton South, Victoria, Australia
| | - Ralph N Martins
- School of Medical Sciences, Edith Cowan University, Joondalup, WA, Australia.,CRC for Mental Health, Carlton South, Victoria, Australia.,Department of Biomedical Sciences, Faculty of Medicine, Health and Human Sciences, Macquarie University, Sydney, NSW, Australia.,School of Psychiatry and Clinical Neurosciences, University of Western Australia, Crawley, WA, Australia
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6
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Rahman SO, Hussain S, Alzahrani A, Akhtar M, Najmi AK. Effect of statins on amyloidosis in the rodent models of Alzheimer's disease: Evidence from the preclinical meta-analysis. Brain Res 2020; 1749:147115. [PMID: 32918868 DOI: 10.1016/j.brainres.2020.147115] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/18/2020] [Revised: 08/26/2020] [Accepted: 09/04/2020] [Indexed: 12/17/2022]
Abstract
INTRODUCTION Previous studies have shown contrasting results in determining efficacy of statins against amyloid beta accumulation. The aim of this study was to assess the impact of statin in AD. METHOD We searched PubMed and Embase for relevant preclinical studies. A meta-analysis of the statin's efficacy on amyloidosis and cognitive impairment was performed. Also, stratified analysis was performed on several covariates including the type of statin used, gender and age of rodents and duration of statin therapy, to account for the reported heterogeneity in the results obtained. The study protocol was registered in PROSPERO (CRD42018102557). RESULT 17 studies including 22 comparisons, containing a sample size of 446 rodents, participated in the meta-analysis of statin's effect on overall Aβ deposition. Although the effect of statin on overall Aβ deposition was found to be protective (p < 0.00001) but as we categorized the efficacy of statin on different Aβ species (soluble and insoluble Aβ40/42) and Aβ plaque load, we found that significance in the protection decreased. A stratified meta-analysis demonstrated a significant role in the duration of statin supplements and rodent's age on the heterogeneity of the results. Statin administered to rodents for the longest duration (>6 months) and younger rodents (<6 months of age) demonstrated significant efficacy of statin on Aβ deposition. CONCLUSION Statin showed reduction in Aβ level but stratified analysis revealed that this effect of statin was dependent on rodent's age and duration of the treatment.
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Affiliation(s)
- Syed Obaidur Rahman
- Pharmaceutical Medicine, Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Salman Hussain
- Pharmaceutical Medicine, Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Abdulaziz Alzahrani
- Department of Pharmacology, College of Clinical Pharmacy, Al Baha University, Al Baha, Saudi Arabia
| | - Mohd Akhtar
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India
| | - Abul Kalam Najmi
- Department of Pharmacology, School of Pharmaceutical Education and Research, Jamia Hamdard, New Delhi 110062, India.
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7
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Yao L, Liu C, Wang N, Du F, Fan S, Guo Y, Zhang L, Pan Y, Xiong W. Cholesterol regulates cannabinoid analgesia through glycine receptors. Neuropharmacology 2020; 177:108242. [DOI: 10.1016/j.neuropharm.2020.108242] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2020] [Revised: 06/20/2020] [Accepted: 07/13/2020] [Indexed: 12/11/2022]
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8
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Bjorkli C, Sandvig A, Sandvig I. Bridging the Gap Between Fluid Biomarkers for Alzheimer's Disease, Model Systems, and Patients. Front Aging Neurosci 2020; 12:272. [PMID: 32982716 PMCID: PMC7492751 DOI: 10.3389/fnagi.2020.00272] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/31/2020] [Accepted: 08/06/2020] [Indexed: 12/12/2022] Open
Abstract
Alzheimer’s disease (AD) is a debilitating neurodegenerative disease characterized by the accumulation of two proteins in fibrillar form: amyloid-β (Aβ) and tau. Despite decades of intensive research, we cannot yet pinpoint the exact cause of the disease or unequivocally determine the exact mechanism(s) underlying its progression. This confounds early diagnosis and treatment of the disease. Cerebrospinal fluid (CSF) biomarkers, which can reveal ongoing biochemical changes in the brain, can help monitor developing AD pathology prior to clinical diagnosis. Here we review preclinical and clinical investigations of commonly used biomarkers in animals and patients with AD, which can bridge translation from model systems into the clinic. The core AD biomarkers have been found to translate well across species, whereas biomarkers of neuroinflammation translate to a lesser extent. Nevertheless, there is no absolute equivalence between biomarkers in human AD patients and those examined in preclinical models in terms of revealing key pathological hallmarks of the disease. In this review, we provide an overview of current but also novel AD biomarkers and how they relate to key constituents of the pathological cascade, highlighting confounding factors and pitfalls in interpretation, and also provide recommendations for standardized procedures during sample collection to enhance the translational validity of preclinical AD models.
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Affiliation(s)
- Christiana Bjorkli
- Sandvig Group, Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
| | - Axel Sandvig
- Sandvig Group, Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway.,Institute of Neuromedicine and Movement Science, Department of Neurology, St. Olavs Hospital, Trondheim, Norway.,Department of Pharmacology and Clinical Neurosciences, Division of Neuro, Head, and Neck, University Hospital of Umeå, Umeå, Sweden
| | - Ioanna Sandvig
- Sandvig Group, Department of Neuromedicine and Movement Science, Faculty of Medicine and Health Sciences, Norwegian University of Science and Technology, Trondheim, Norway
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Chew H, Solomon VA, Fonteh AN. Involvement of Lipids in Alzheimer's Disease Pathology and Potential Therapies. Front Physiol 2020; 11:598. [PMID: 32581851 PMCID: PMC7296164 DOI: 10.3389/fphys.2020.00598] [Citation(s) in RCA: 156] [Impact Index Per Article: 39.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/28/2020] [Accepted: 05/14/2020] [Indexed: 12/15/2022] Open
Abstract
Lipids constitute the bulk of the dry mass of the brain and have been associated with healthy function as well as the most common pathological conditions of the brain. Demographic factors, genetics, and lifestyles are the major factors that influence lipid metabolism and are also the key components of lipid disruption in Alzheimer's disease (AD). Additionally, the most common genetic risk factor of AD, APOE ϵ4 genotype, is involved in lipid transport and metabolism. We propose that lipids are at the center of Alzheimer's disease pathology based on their involvement in the blood-brain barrier function, amyloid precursor protein (APP) processing, myelination, membrane remodeling, receptor signaling, inflammation, oxidation, and energy balance. Under healthy conditions, lipid homeostasis bestows a balanced cellular environment that enables the proper functioning of brain cells. However, under pathological conditions, dyshomeostasis of brain lipid composition can result in disturbed BBB, abnormal processing of APP, dysfunction in endocytosis/exocytosis/autophagocytosis, altered myelination, disturbed signaling, unbalanced energy metabolism, and enhanced inflammation. These lipid disturbances may contribute to abnormalities in brain function that are the hallmark of AD. The wide variance of lipid disturbances associated with brain function suggest that AD pathology may present as a complex interaction between several metabolic pathways that are augmented by risk factors such as age, genetics, and lifestyles. Herewith, we examine factors that influence brain lipid composition, review the association of lipids with all known facets of AD pathology, and offer pointers for potential therapies that target lipid pathways.
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Affiliation(s)
- Hannah Chew
- Huntington Medical Research Institutes, Pasadena, CA, United States
- University of California, Los Angeles, Los Angeles, CA, United States
| | | | - Alfred N. Fonteh
- Huntington Medical Research Institutes, Pasadena, CA, United States
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10
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Alam J, Sharma L. Potential Enzymatic Targets in Alzheimer's: A Comprehensive Review. Curr Drug Targets 2020; 20:316-339. [PMID: 30124150 DOI: 10.2174/1389450119666180820104723] [Citation(s) in RCA: 23] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2018] [Revised: 06/23/2018] [Accepted: 08/15/2018] [Indexed: 12/13/2022]
Abstract
Alzheimer's, a degenerative cause of the brain cells, is called as a progressive neurodegenerative disease and appears to have a heterogeneous etiology with main emphasis on amyloid-cascade and hyperphosphorylated tau-cascade hypotheses, that are directly linked with macromolecules called enzymes such as β- & γ-secretases, colinesterases, transglutaminases, and glycogen synthase kinase (GSK-3), cyclin-dependent kinase (cdk-5), microtubule affinity-regulating kinase (MARK). The catalytic activity of the above enzymes is the result of cognitive deficits, memory impairment and synaptic dysfunction and loss, and ultimately neuronal death. However, some other enzymes also lead to these dysfunctional events when reduced to their normal activities and levels in the brain, such as α- secretase, protein kinase C, phosphatases etc; metabolized to neurotransmitters, enzymes like monoamine oxidase (MAO), catechol-O-methyltransferase (COMT) etc. or these abnormalities can occur when enzymes act by other mechanisms such as phosphodiesterase reduces brain nucleotides (cGMP and cAMP) levels, phospholipase A2: PLA2 is associated with reactive oxygen species (ROS) production etc. On therapeutic fronts, several significant clinical trials are underway by targeting different enzymes for development of new therapeutics to treat Alzheimer's, such as inhibitors for β-secretase, GSK-3, MAO, phosphodiesterase, PLA2, cholinesterases etc, modulators of α- & γ-secretase activities and activators for protein kinase C, sirtuins etc. The last decades have perceived an increasing focus on findings and search for new putative and novel enzymatic targets for Alzheimer's. Here, we review the functions, pathological roles, and worth of almost all the Alzheimer's associated enzymes that address to therapeutic strategies and preventive approaches for treatment of Alzheimer's.
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Affiliation(s)
- Jahangir Alam
- School of Pharmaceutical Sciences, Shoolini University, Solan, H.P., Pin 173229, India
| | - Lalit Sharma
- School of Pharmaceutical Sciences, Shoolini University, Solan, H.P., Pin 173229, India
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11
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Diagnosis of Alzheimer's disease utilizing amyloid and tau as fluid biomarkers. Exp Mol Med 2019; 51:1-10. [PMID: 31073121 PMCID: PMC6509326 DOI: 10.1038/s12276-019-0250-2] [Citation(s) in RCA: 121] [Impact Index Per Article: 24.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/24/2018] [Accepted: 12/26/2018] [Indexed: 01/01/2023] Open
Abstract
Current technological advancements in clinical and research settings have permitted a more intensive and comprehensive understanding of Alzheimer’s disease (AD). This development in knowledge regarding AD pathogenesis has been implemented to produce disease-modifying drugs. The potential for accessible and effective therapeutic methods has generated a need for detecting this neurodegenerative disorder during early stages of progression because such remedial effects are more profound when implemented during the initial, prolonged prodromal stages of pathogenesis. The aggregation of amyloid-β (Aβ) and tau isoforms are characteristic of AD; thus, they are considered core candidate biomarkers. However, research attempting to establish the reliability of Aβ and tau as biomarkers has culminated in an amalgamation of contradictory results and theories regarding the biomarker concentrations necessary for an accurate diagnosis. In this review, we consider the capabilities and limitations of fluid biomarkers collected from cerebrospinal fluid, blood, and oral, ocular, and olfactory secretions as diagnostic tools for AD, along with the impact of the integration of these biomarkers in clinical settings. Furthermore, the evolution of diagnostic criteria and novel research findings are discussed. This review is a summary and reflection of the ongoing concerted efforts to establish fluid biomarkers as a diagnostic tool and implement them in diagnostic procedures. Markers from body fluids could help clinicians diagnose Alzheimer’s disease before cognitive decline appears. After numerous setbacks in treating advanced Alzheimer’s, researchers are eager to identify biological indicators that facilitate earlier disease detection and interception. A review by YoungSoo Kim and colleagues at Yonsei University in South Korea, explores the promise of ‘fluid biomarkers,’ which enables diagnosis using cerebrospinal fluid (CSF), blood, oral, ocular, and olfactory fluid samples. Shifts in CSF levels of amyloid beta and tau, two proteins central to Alzheimer’s pathology, can reliably monitor at-risk individuals. Although CSF collection is unpleasant for patients, it remains more promising than blood, where current data for candidate fluid biomarkers are relatively inconclusive. In this review, investigations to discover safer, cheaper, and more reliable diagnostic tools to shift treatment from alleviation to prevention are introduced.
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12
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Kim Y, Yoo YK, Kim HY, Roh JH, Kim J, Baek S, Lee JC, Kim HJ, Chae MS, Jeong D, Park D, Lee S, Jang H, Kim K, Lee JH, Byun BH, Park SY, Ha JH, Lee KC, Cho WW, Kim JS, Koh JY, Lim SM, Hwang KS. Comparative analyses of plasma amyloid-β levels in heterogeneous and monomerized states by interdigitated microelectrode sensor system. SCIENCE ADVANCES 2019; 5:eaav1388. [PMID: 31001580 PMCID: PMC6469948 DOI: 10.1126/sciadv.aav1388] [Citation(s) in RCA: 25] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 08/17/2018] [Accepted: 02/25/2019] [Indexed: 05/31/2023]
Abstract
Detection of amyloid-β (Aβ) aggregates contributes to the diagnosis of Alzheimer disease (AD). Plasma Aβ is deemed a less invasive and more accessible hallmark of AD, as Aβ can penetrate blood-brain barriers. However, correlations between biofluidic Aβ concentrations and AD progression has been tenuous. Here, we introduce a diagnostic technique that compares the heterogeneous and the monomerized states of Aβ in plasma. We used a small molecule, EPPS [4-(2-hydroxyethyl)-1-piperazinepropanesulfonic acid], to dissociate aggregated Aβ into monomers to enhance quantification accuracy. Subsequently, Aβ levels of EPPS-treated plasma were compared to those of untreated samples to minimize inter- and intraindividual variations. The interdigitated microelectrode sensor system was used to measure plasma Aβ levels on a scale of 0.1 pg/ml. The implementation of this self-standard blood test resulted in substantial distinctions between patients with AD and individuals with normal cognition (NC), with selectivity and sensitivity over 90%.
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Affiliation(s)
- YoungSoo Kim
- Integrated Science and Engineering Division, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Yong Kyoung Yoo
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
- Department of Electrical Engineering, Kwangwoon University, 20 Kwangwoon-ro, Nowon-gu, Seoul 01897, Republic of Korea
| | - Hye Yun Kim
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Jee Hoon Roh
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
| | - Jinsik Kim
- Department of Medical Biotechnology, Dongguk University, 30 Pildong-ro 1-gil, Jung-gu, Seoul 04620, Republic of Korea
| | - Seungyeop Baek
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Department of Biotechnology, Yonsei University, 50 Yonsei-ro Seodaemun-gu, Seoul 03722, Republic of Korea
- Brain Science Institute, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Jinny Claire Lee
- Integrated Science and Engineering Division, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Hye Jin Kim
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
| | - Myung-Sic Chae
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
| | - Dahye Jeong
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
| | - Dongsung Park
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
| | - Sejin Lee
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Brain Science Institute, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - HoChung Jang
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Brain Science Institute, Korea Institute of Science and Technology, 5 Hwarang-ro 14-gil, Seongbuk-gu, Seoul 02792, Republic of Korea
| | - Kyeonghwan Kim
- Department of Pharmacy, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
- Yonsei Institute of Pharmaceutical Sciences, Yonsei University, 85 Songdogwahak-ro, Yeonsu-gu, Incheon 21983, Republic of Korea
| | - Jeong Hoon Lee
- Department of Electrical Engineering, Kwangwoon University, 20 Kwangwoon-ro, Nowon-gu, Seoul 01897, Republic of Korea
| | - Byung Hyun Byun
- Department of Nuclear Medicine, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Su Yeon Park
- Department of Neurology of Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Jeong Ho Ha
- Department of Neurology of Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Kyo Chul Lee
- Division of RI-Convergence Research, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Won Woo Cho
- Cantis, Sangnok-gu, Ansan-si, Gyeonggi-do 15588, Republic of Korea
| | - Jae-Seung Kim
- Department of Nuclear Medicine, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
| | - Jae-Young Koh
- Department of Neurology, Asan Medical Center, University of Ulsan College of Medicine, 88 Olympic-ro 43-gil, Songpa-gu, Seoul 05505, Republic of Korea
| | - Sang Moo Lim
- Department of Neurology of Korea Cancer Center Hospital, Korea Institute of Radiological & Medical Sciences, 75 Nowon-ro, Nowon-gu, Seoul 01812, Republic of Korea
| | - Kyo Seon Hwang
- Department of Clinical Pharmacology and Therapeutics, College of Medicine, Kyung Hee University, 26 Kyungheedae-ro, Dongdaemun-gu, Seoul 02447, Republic of Korea
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Fracassi A, Marangoni M, Rosso P, Pallottini V, Fioramonti M, Siteni S, Segatto M. Statins and the Brain: More than Lipid Lowering Agents? Curr Neuropharmacol 2019; 17:59-83. [PMID: 28676012 PMCID: PMC6341496 DOI: 10.2174/1570159x15666170703101816] [Citation(s) in RCA: 65] [Impact Index Per Article: 13.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2017] [Revised: 05/24/2017] [Accepted: 06/26/2017] [Indexed: 01/21/2023] Open
Abstract
BACKGROUND Statins represent a class of medications widely prescribed to efficiently treat dyslipidemia. These drugs inhibit 3-βhydroxy 3β-methylglutaryl Coenzyme A reductase (HMGR), the rate-limiting enzyme of mevalonate (MVA) pathway. Besides cholesterol, MVA pathway leads to the production of several other compounds, which are essential in the regulation of a plethora of biological activities, including in the central nervous system. For these reasons, statins are able to induce pleiotropic actions, and acquire increased interest as potential and novel modulators in brain processes, especially during pathological conditions. OBJECTIVE The purpose of this review is to summarize and examine the current knowledge about pharmacokinetic and pharmacodynamic properties of statins in the brain. In addition, effects of statin on brain diseases are discussed providing the most up-to-date information. METHODS Relevant scientific information was identified from PubMed database using the following keywords: statins and brain, central nervous system, neurological diseases, neurodegeneration, brain tumors, mood, stroke. RESULTS 315 scientific articles were selected and analyzed for the writing of this review article. Several papers highlighted that statin treatment is effective in preventing or ameliorating the symptomatology of a number of brain pathologies. However, other studies failed to demonstrate a neuroprotective effect. CONCLUSION Even though considerable research studies suggest pivotal functional outcomes induced by statin therapy, additional investigation is required to better determine the pharmacological effectiveness of statins in the brain, and support their clinical use in the management of different neuropathologies.
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Affiliation(s)
| | | | | | | | | | | | - Marco Segatto
- Address correspondence to this author at the Department of Sense Organs, Sapienza University, viale del Policlinico 155, 00186 Rome, Italy; E-mail:
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Hu X, Song C, Fang M, Li C. Simvastatin inhibits the apoptosis of hippocampal cells in a mouse model of Alzheimer's disease. Exp Ther Med 2017; 15:1795-1802. [PMID: 29434767 PMCID: PMC5776644 DOI: 10.3892/etm.2017.5620] [Citation(s) in RCA: 7] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/15/2016] [Accepted: 03/24/2017] [Indexed: 01/28/2023] Open
Abstract
Alzheimer's disease is associated with cognitive impairments that affect memory and executive functions. Simvastatin is a cholesterol-lowering statin drug that is used to control levels of cholesterol in the blood, particularly in cases of hypercholesterolemia, and may be used in the treatment of aneurysmal subarachnoid hemorrhage. Previous results have indicated that the apoptosis of hippocampal cells may serve a critical role in the progression of Alzheimer's disease. In the present study, it was determined whether Simvastatin inhibited the apoptosis of hippocampal cells in vitro and in vivo. The therapeutic effects of Simvastatin were evaluated in 24-month-old triple-transgenic Alzheimer's disease (3×Tg-AD) mice, and the efficacy of Simvastatin in attenuating memory and cognitive impairment was investigated. Levels of apoptosis-related gene expression in the hippocampus and hippocampal cells of experimental mice were also detected. In addition, neuron excitability was assessed in the functionally relevant brain regions in the hippocampus. The data indicated that Simvastatin significantly suppressed the apoptosis of hippocampal cells in 3×Tg-AD model mice compared with controls (P<0.01). Furthermore, treatment with Simvastatin improved the dementia status of 3×Tg-AD mice, as determined by a learning task in which mice exhibited significantly reduced attention impairment, impulsivity and compulsivity (P<0.01). In addition, results demonstrated that Simvastatin significantly inhibited hippocampal damage and significantly improved neuronal loss in hippocampal structures classically associated with attentional performance when compared with untreated mice (P<0.01). Thus, Simvastatin prevented cognitive impairment by decreasing hippocampal cell apoptosis and improving learning-memory ability. Simvastatin treatment also increased the expression of anti-apoptotic genes and decreased the expression pro-apoptotic genes (P<0.01), which may have been associated with improved motor attention and cognitive competence in 3×Tg-AD mice. Collectively, these preclinical data indicated that Simvastatin was efficient in attenuating memory lapse and hippocampal cell apoptosis in a 3×Tg-AD mouse model. Thus, Simvastatin may be useful in improving the clinical outcome of patients with Alzheimer's disease.
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Affiliation(s)
- Xiaoqin Hu
- Department of Neurology, Remnin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
| | - Chengwei Song
- Department of Neurology, The First Hospital of Yichang, The Gorges University College of Medicine, Yichang, Hubei 443000, P.R. China
| | - Ming Fang
- Department of Neurology, The First Hospital of Yichang, The Gorges University College of Medicine, Yichang, Hubei 443000, P.R. China
| | - Chengyan Li
- Department of Neurology, Remnin Hospital of Wuhan University, Wuhan, Hubei 430060, P.R. China
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15
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Mendoza-Oliva A, Ferrera P, Fragoso-Medina J, Arias C. Lovastatin Differentially Affects Neuronal Cholesterol and Amyloid-β Production in vivo and in vitro. CNS Neurosci Ther 2015; 21:631-41. [PMID: 26096465 DOI: 10.1111/cns.12420] [Citation(s) in RCA: 11] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2015] [Revised: 05/08/2015] [Accepted: 05/22/2015] [Indexed: 12/25/2022] Open
Abstract
BACKGROUND AND AIMS Epidemiological and experimental studies indicate that high cholesterol may increase susceptibility to age-associated neurodegenerative disorders, such as Alzheimer's disease (AD). Thus, it has been suggested that statins, which are inhibitors of the enzyme 3-hydroxy-3-methylglutaryl-CoA reductase (HMGCR), may be a useful therapeutic tool to diminish the risk of AD. However, several studies that analyzed the therapeutic benefits of statins have yielded conflicting results. Herein, we investigated the role of lovastatin on neuronal cholesterol homeostasis and its effects on amyloid β protein production in vivo and in vitro. METHODS AND RESULTS Lovastatin effects were analyzed in vitro using differentiated human neuroblastoma cells and in vivo in a lovastatin-fed rat model. We demonstrated that lovastatin can differentially affect the expression of APP and Aβ production in vivo and in vitro. Lovastatin-induced HMGCR inhibition was detrimental to neuronal survival in vitro via a mechanism unrelated to the reduction of cholesterol. We found that in vivo, dietary cholesterol was associated with increased Aβ production in the cerebral cortex, and lovastatin was not able to reduce cholesterol levels. However, lovastatin induced a remarkable increase in the mature form of the sterol regulatory element-binding protein-2 (SREBP-2) as well as its target gene HMGCR, in both neuronal cells and in the brain. CONCLUSIONS Lovastatin modifies the mevalonate pathway without affecting cholesterol levels in vivo and is able to reduce Aβ levels only in vitro.
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Affiliation(s)
- Aydé Mendoza-Oliva
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México D.F, México
| | - Patricia Ferrera
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México D.F, México
| | - Jorge Fragoso-Medina
- Departmento de Bioquímica, Facultad de Medicina, Universidad Nacional Autónoma de México, México D.F, México
| | - Clorinda Arias
- Departamento de Medicina Genómica y Toxicología Ambiental, Instituto de Investigaciones Biomédicas, Universidad Nacional Autónoma de México, México D.F, México
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Malnar M, Hecimovic S, Mattsson N, Zetterberg H. Bidirectional links between Alzheimer's disease and Niemann-Pick type C disease. Neurobiol Dis 2014; 72 Pt A:37-47. [PMID: 24907492 DOI: 10.1016/j.nbd.2014.05.033] [Citation(s) in RCA: 59] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/13/2014] [Revised: 05/17/2014] [Accepted: 05/27/2014] [Indexed: 12/20/2022] Open
Abstract
Alzheimer's disease (AD) and Niemann-Pick type C (NPC) disease are progressive neurodegenerative diseases with very different epidemiology and etiology. AD is a common cause of dementia with a complex polyfactorial etiology, including both genetic and environmental risk factors, while NPC is a very rare autosomal recessive disease. However, the diseases share some disease-related molecular pathways, including abnormal cholesterol metabolism, and involvement of amyloid-β (Aβ) and tau pathology. Here we review recent studies on these pathological traits, focusing on studies of Aβ and tau pathology in NPC, and the importance of the NPC1 gene in AD. Further studies of similarities and differences between AD and NPC may be useful to increase the understanding of both these devastating neurological diseases.
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Affiliation(s)
- Martina Malnar
- Division of Molecular Medicine, Rudjer Boskovic Institute, Zagreb, Croatia
| | - Silva Hecimovic
- Division of Molecular Medicine, Rudjer Boskovic Institute, Zagreb, Croatia.
| | - Niklas Mattsson
- Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Gothenburg, Sweden; Center for Imaging of Neurodegenerative Diseases (CIND), San Francisco VA Medical Center, San Francisco, CA, USA; Department of Radiology and Biomedical Imaging, University of California, San Francisco, CA, USA
| | - Henrik Zetterberg
- Clinical Neurochemistry Laboratory, Institute of Neuroscience and Physiology, Department of Psychiatry and Neurochemistry, The Sahlgrenska Academy, University of Gothenburg, Mölndal, Gothenburg, Sweden; UCL Institute of Neurology, Queen Square, London WC1N 3BG, UK.
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Abstract
The demonstrated benefits of 3-hydroxy-3-methylglutaryl coenzyme A (HMG-CoA) reductase inhibitors (statins) for cardiovascular and cerebrovascular disease are well established in the medical literature, and this class of medications is among those most commonly prescribed in the USA. In 2012, the US Food and Drug Administration issued updated recommendations regarding statin medications, and the panel's comments regarding memory impairment fostered clinical confusion (in part because of the lay media's amplification). Cognitive data from several large epidemiological studies have not reliably demonstrated a robust association between incident cognitive impairment and statin use, with some studies reporting a protective effect, some reporting an increased risk and others finding no association. Although several interventional studies have evaluated statins as a possible adjunctive treatment for Alzheimer's disease, none have clearly demonstrated a benefit. A small number of case series have reported infrequent memory difficulties associated with statin use. In these series, the patients' cognitive symptoms resolved after statin discontinuation. The existing medical literature does not suggest that cognitive considerations should play a major role in medical decision making to prescribe statins for the large majority of patients. As with any medication prescribed for older adults, careful clinical monitoring for side effects should be exercised. If a patient is suspected of having idiosyncratic memory impairment associated with use of a statin medication, the drug can be discontinued. The patient should then be followed with careful clinical observation for 1-3 months for resolution of the cognitive symptoms.
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Affiliation(s)
- Brendan J Kelley
- Department of Neurology, The Ohio State University, Columbus, OH, 43210, USA,
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Shinohara M, Sato N, Shimamura M, Kurinami H, Hamasaki T, Chatterjee A, Rakugi H, Morishita R. Possible modification of Alzheimer's disease by statins in midlife: interactions with genetic and non-genetic risk factors. Front Aging Neurosci 2014; 6:71. [PMID: 24795626 PMCID: PMC4005936 DOI: 10.3389/fnagi.2014.00071] [Citation(s) in RCA: 35] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/25/2014] [Accepted: 03/30/2014] [Indexed: 12/28/2022] Open
Abstract
The benefits of statins, commonly prescribed for hypercholesterolemia, in treating Alzheimer's disease (AD) have not yet been fully established. A recent randomized clinical trial did not show any therapeutic effects of two statins on cognitive function in AD. Interestingly, however, the results of the Rotterdam study, one of the largest prospective cohort studies, showed reduced risk of AD in statin users. Based on the current understanding of statin actions and AD pathogenesis, it is still worth exploring whether statins can prevent AD when administered decades before the onset of AD or from midlife. This review discusses the possible beneficial effects of statins, drawn from previous clinical observations, pathogenic mechanisms, which include β-amyloid (Aβ) and tau metabolism, genetic and non-genetic risk factors (apolipoprotein E, cholesterol, sex, hypertension, and diabetes), and other clinical features (vascular dysfunction and oxidative and inflammatory stress) of AD. These findings suggest that administration of statins in midlife might prevent AD in late life by modifying genetic and non-genetic risk factors for AD. It should be clarified whether statins inhibit Aβ accumulation, tau pathological features, and brain atrophy in humans. To answer this question, a randomized controlled study using amyloid positron emission tomography (PET), tau-PET, and magnetic resonance imaging would be useful. This clinical evaluation could help us to overcome this devastating disease.
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Affiliation(s)
- Mitsuru Shinohara
- Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka UniversitySuita, Japan
- Department of Geriatric Medicine, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Naoyuki Sato
- Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka UniversitySuita, Japan
- Department of Geriatric Medicine, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Munehisa Shimamura
- Division of Vascular Medicine and Epigenetics, Department of Child Development, United Graduate School of Child Development, Osaka University Office for University-Industry CollaborationSuita, Japan
| | - Hitomi Kurinami
- Division of Vascular Medicine and Epigenetics, Department of Child Development, United Graduate School of Child Development, Osaka University Office for University-Industry CollaborationSuita, Japan
| | - Toshimitsu Hamasaki
- Department of Biomedical Statistics, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Amarnath Chatterjee
- Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Hiromi Rakugi
- Department of Geriatric Medicine, Graduate School of Medicine, Osaka UniversitySuita, Japan
| | - Ryuichi Morishita
- Department of Clinical Gene Therapy, Graduate School of Medicine, Osaka UniversitySuita, Japan
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Murao K, Bombois S, Cordonnier C, Hénon H, Bordet R, Pasquier F, Leys D. Influence of cognitive impairment on the management of ischaemic stroke. Rev Neurol (Paris) 2014; 170:177-86. [PMID: 24613474 DOI: 10.1016/j.neurol.2014.01.665] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/26/2013] [Revised: 01/03/2014] [Accepted: 01/30/2014] [Indexed: 12/19/2022]
Abstract
BACKGROUND Because of ageing of the population, it is more and more frequent to treat ischaemic stroke patients with pre-stroke cognitive impairment (PSCI). Currently, there is no specific recommendation on ischaemic stroke management in these patients, both at the acute stage and in secondary prevention. However, these patients are less likely to receive treatments proven effective in randomised controlled trials, even in the absence of contra-indication. OBJECTIVE To review the literature to assess efficacy and safety of validated therapies for acute ischaemic stroke and secondary prevention in PSCI patients. RESULTS Most randomised trials did not take into account the pre-stroke cognitive status. The few observational studies conducted at the acute stage or in secondary prevention, did not provide any information that the benefit could be either lost or replaced by harm in the presence of PSCI. CONCLUSIONS There is no reason not to treat ischaemic stroke patients with PSCI according to the currently available recommendations for acute management and secondary prevention. Further observational studies are needed and pre-stroke cognition should be taken into account in future stroke trials.
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Affiliation(s)
- K Murao
- EA 1046, Departments of Neurology, University Lille North of France, UDSL, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France
| | - S Bombois
- EA 1046, Departments of Neurology, University Lille North of France, UDSL, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France; Departments of Neurology, Memory Centre, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France.
| | - C Cordonnier
- EA 1046, Departments of Neurology, University Lille North of France, UDSL, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France; Departments of Neurology, Stroke centre, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France
| | - H Hénon
- EA 1046, Departments of Neurology, University Lille North of France, UDSL, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France; Departments of Neurology, Stroke centre, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France
| | - R Bordet
- EA 1046, Departments of Neurology, University Lille North of France, UDSL, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France; Department, of Pharmacology. Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France
| | - F Pasquier
- EA 1046, Departments of Neurology, University Lille North of France, UDSL, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France; Departments of Neurology, Memory Centre, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France
| | - D Leys
- EA 1046, Departments of Neurology, University Lille North of France, UDSL, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France; Departments of Neurology, Stroke centre, Lille University Hospital, 1, place de Verdun, 59045 Lille cedex, France
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20
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Léger GC, Massoud F. Novel disease-modifying therapeutics for the treatment of Alzheimer’s disease. Expert Rev Clin Pharmacol 2014; 6:423-42. [DOI: 10.1586/17512433.2013.811237] [Citation(s) in RCA: 7] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
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21
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Mai W, Hu X, Lu Z, Peng F, Wang Y. Cerebrospinal Fluid Levels of Soluble Amyloid Precursor Protein and β-Amyloid 42 in Patients with Multiple Sclerosis, Neuromyelitis Optica and Clinically Isolated Syndrome. J Int Med Res 2011; 39:2402-13. [PMID: 22289560 DOI: 10.1177/147323001103900641] [Citation(s) in RCA: 14] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/21/2023] Open
Abstract
Amyloid precursor protein (APP) accumulation in axonal ovoids is a sensitive marker for acute axonal injury in multiple sclerosis (MS) lesions. This study measured levels of α-cleaved soluble APP (αsAPP) and β-amyloid 42 (Aβ42) in the cerebrospinal fluid (CSF) of 42 MS, 10 neuromyelitis optica and 25 clinically isolated syndrome patients and 21 healthy controls, and analysed the correlation between αsAPP and Aβ42 levels and relevant clinical parameters. The CSF concentrations of αsAPP and Aβ42 in patients and controls were not significantly different. There was a significant inverse correlation in patients between CSF asAPP concentration and the Expanded Disability Status Scale (EDSS), but no significant correlation between CSF Aβ42 concentration and EDSS. The concentration of αsAPP in the CSF of statin-treated patients was significantly higher than in those not treated with statins, suggesting that statins may have a neuroprotective effect. In conclusion, αsAPP was present at similar levels in the CSF of patients with neuromyelitis optica, MS and clinically isolated syndrome and healthy controls, and an inverse correlation existed between CSF αsAPP concentration and neurological disability.
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Affiliation(s)
- W Mai
- Department of Neurology, The Fifth Affiliated Hospital of Sun Yat-Sen University, Zhuhai, China
| | - X Hu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Z Lu
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - F Peng
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
| | - Y Wang
- Department of Neurology, The Third Affiliated Hospital of Sun Yat-Sen University, Guangzhou, China
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22
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Statins and their influence on brain cholesterol. J Clin Lipidol 2011; 5:373-9. [DOI: 10.1016/j.jacl.2011.06.007] [Citation(s) in RCA: 29] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/15/2011] [Revised: 06/01/2011] [Accepted: 06/10/2011] [Indexed: 11/15/2022]
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23
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Creed MC, Milgram NW. Amyloid-modifying therapies for Alzheimer's disease: therapeutic progress and its implications. AGE (DORDRECHT, NETHERLANDS) 2010; 32:365-84. [PMID: 20640545 PMCID: PMC2926857 DOI: 10.1007/s11357-010-9142-z] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/27/2009] [Accepted: 03/25/2010] [Indexed: 05/03/2023]
Abstract
Alzheimer's disease (AD) is the most prevalent form of dementia, affecting an estimated 4.8 million people in North America. For the past decade, the amyloid cascade hypothesis has dominated the field of AD research. This theory posits that the deposition of amyloid-beta protein (Abeta) in the brain is the key pathologic event in AD, which induces a series of neuropathological changes that manifest as cognitive decline and eventual dementia. Based on this theory, interventions that reduce Abeta burden in the brain would be expected to alleviate both the neuropathological changes and dementia, which characterize AD. Several diverse pharmacological strategies have been developed to accomplish this. These include inhibiting the formation of Abeta, preventing the aggregation of Abeta into insoluble aggregates, preventing the entry of Abeta into the brain from the periphery and enhancing the clearance of Abeta from the central nervous system. To date, no amyloid-modifying therapy has yet been successful in phase 3 clinical trials; however, several trials are currently underway. This article provides a review of the status of amyloid-modifying therapies and the implications for the amyloid cascade hypothesis.
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Affiliation(s)
- Meaghan C Creed
- Department of Pharmacology and Toxicology, University of Toronto, Toronto, ON M5S 1A8, Canada.
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Schreurs BG. The effects of cholesterol on learning and memory. Neurosci Biobehav Rev 2010; 34:1366-79. [PMID: 20470821 PMCID: PMC2900496 DOI: 10.1016/j.neubiorev.2010.04.010] [Citation(s) in RCA: 76] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/10/2010] [Revised: 04/26/2010] [Accepted: 04/28/2010] [Indexed: 02/07/2023]
Abstract
Cholesterol is vital to normal brain function including learning and memory but that involvement is as complex as the synthesis, metabolism and excretion of cholesterol itself. Dietary cholesterol influences learning tasks from water maze to fear conditioning even though cholesterol does not cross the blood brain barrier. Excess cholesterol has many consequences including peripheral pathology that can signal brain via cholesterol metabolites, pro-inflammatory mediators and antioxidant processes. Manipulations of cholesterol within the central nervous system through genetic, pharmacological, or metabolic means circumvent the blood brain barrier and affect learning and memory but often in animals already otherwise compromised. The human literature is no less complex. Cholesterol reduction using statins improves memory in some cases but not others. There is also controversy over statin use to alleviate memory problems in Alzheimer's disease. Correlations of cholesterol and cognitive function are mixed and association studies find some genetic polymorphisms are related to cognitive function but others are not. In sum, the field is in flux with a number of seemingly contradictory results and many complexities. Nevertheless, understanding cholesterol effects on learning and memory is too important to ignore.
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Affiliation(s)
- Bernard G Schreurs
- Blanchette Rockefeller Neurosciences Institute and Department of Physiology and Pharmacology, West Virginia University School of Medicine, BRNI Building, Morgantown, WV 26505-3409-08, USA.
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Serrano-Pozo A, Vega GL, Lütjohann D, Locascio JJ, Tennis MK, Deng A, Atri A, Hyman BT, Irizarry MC, Growdon JH. Effects of simvastatin on cholesterol metabolism and Alzheimer disease biomarkers. Alzheimer Dis Assoc Disord 2010; 24:220-6. [PMID: 20473136 PMCID: PMC3694274 DOI: 10.1097/wad.0b013e3181d61fea] [Citation(s) in RCA: 50] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
Preclinical and epidemiologic studies suggest a protective effect of statins on Alzheimer disease (AD). Experimental evidence indicates that some statins can cross the blood-brain barrier, alter brain cholesterol metabolism, and may ultimately decrease the production of amyloid-beta (Abeta) peptide. Despite these promising leads, clinical trials have yielded inconsistent results regarding the benefits of statin treatment in AD. Seeking to detect a biological signal of statins effect on AD, we conducted a 12-week open-label trial with simvastatin 40 mg/d and then 80 mg/d in 12 patients with AD or amnestic mild cognitive impairment and hypercholesterolemia. We quantified cholesterol precursors and metabolites and AD biomarkers of Abeta and tau in both plasma and cerebrospinal fluid at baseline and after the 12-week treatment period. We found a modest but significant inhibition of brain cholesterol biosynthesis after simvastatin treatment, as indexed by a decrease of cerebrospinal fluid lathosterol and plasma 24S-hydroxycholesterol. Despite this effect, there were no changes in AD biomarkers. Our findings indicate that simvastatin treatment can affect brain cholesterol metabolism within 12 weeks, but did not alter molecular indices of AD pathology during this short-term treatment.
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Affiliation(s)
- Alberto Serrano-Pozo
- Memory Disorders Unit, Department of Neurology and Massachusetts Alzheimer's Disease Research Center. Massachusetts General Hospital, Boston
- Harvard Medical School, Boston
- Servicio de Neurología, Instituto de Biomedicina de Sevilla (IBiS), Hospitales Universitarios Virgen del Rocío, Av. Manuel Siurot s/n, 41013 Seville, Spain
| | - Gloria L. Vega
- Department of Clinical Nutrition, Center for Human Nutrition, University of Texas Southwestern Medical Center, Dallas, TX
| | - Dieter Lütjohann
- Institute of Clinical Chemistry and Pharmacology. University of Bonn, Bonn, Germany
| | - Joseph J. Locascio
- Memory Disorders Unit, Department of Neurology and Massachusetts Alzheimer's Disease Research Center. Massachusetts General Hospital, Boston
- Harvard Medical School, Boston
| | - Marsha K. Tennis
- Memory Disorders Unit, Department of Neurology and Massachusetts Alzheimer's Disease Research Center. Massachusetts General Hospital, Boston
| | - Amy Deng
- Memory Disorders Unit, Department of Neurology and Massachusetts Alzheimer's Disease Research Center. Massachusetts General Hospital, Boston
| | - Alireza Atri
- Memory Disorders Unit, Department of Neurology and Massachusetts Alzheimer's Disease Research Center. Massachusetts General Hospital, Boston
- Harvard Medical School, Boston
- Center for Translational Cognitive Neuroscience, and Geriatric Research, Education and Clinical Center, Veterans Administration Bedford Medical Center, Bedford, MA
| | - Bradley T. Hyman
- Memory Disorders Unit, Department of Neurology and Massachusetts Alzheimer's Disease Research Center. Massachusetts General Hospital, Boston
- Harvard Medical School, Boston
| | - Michael C. Irizarry
- Memory Disorders Unit, Department of Neurology and Massachusetts Alzheimer's Disease Research Center. Massachusetts General Hospital, Boston
| | - John H. Growdon
- Memory Disorders Unit, Department of Neurology and Massachusetts Alzheimer's Disease Research Center. Massachusetts General Hospital, Boston
- Harvard Medical School, Boston
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Rojo L, Sjöberg MK, Hernández P, Zambrano C, Maccioni RB. Roles of cholesterol and lipids in the etiopathogenesis of Alzheimer's disease. J Biomed Biotechnol 2010; 2006:73976. [PMID: 17047312 PMCID: PMC1559932 DOI: 10.1155/jbb/2006/73976] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022] Open
Abstract
Alzheimer's disease is the principal cause of dementia throughout the world and the fourth cause of death in developed economies.This brain disorder is characterized by the formation of brain protein aggregates, namely, the paired helical filaments and senile plaques. Oxidative stress during life, neuroinflamamtion, and alterations in neuron-glia interaction patterns have been also involved in the etiopathogenesis of this disease. In recent years, cumulative evidence has been gained on the involvement of alteration in neuronal lipoproteins activity, as well as on the role of cholesterol and other lipids in the pathogenesis of this neurodegenerative disorder. In this review, we analyze the links between changes in cholesterol homeostasis, and the changes of lipids of major importance for neuronal activity and Alheimer's disease. The investigation on the fine molecular mechanisms underlying the lipids influence in the etiopathogenesis of Alzheimer's disease may shed light into its treatment and medical management.
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Affiliation(s)
- Leonel Rojo
- Laboratory of Cellular and Molecular Biology and Neurosciences, Millennium Institute for Advanced Studies in
Cell Biology and Biotechnology (CBB), Millennium Building, Las Encinas 3370, Ñuñoa, Santiago, Chile
- Department of Chemistry, Arturo Prat University, avenue Arturo Prat 2120, Iquique, Chile
| | - Marcela K. Sjöberg
- Laboratory of Cellular and Molecular Biology and Neurosciences, Millennium Institute for Advanced Studies in
Cell Biology and Biotechnology (CBB), Millennium Building, Las Encinas 3370, Ñuñoa, Santiago, Chile
- Department of Neurological Sciences, Faculty of Medicine, University of Chile, Salvador 486, 750-0922 Providencia,
Santiago, Chile
| | - Paula Hernández
- Laboratory of Cellular and Molecular Biology and Neurosciences, Millennium Institute for Advanced Studies in
Cell Biology and Biotechnology (CBB), Millennium Building, Las Encinas 3370, Ñuñoa, Santiago, Chile
- Department of Neurological Sciences, Faculty of Medicine, University of Chile, Salvador 486, 750-0922 Providencia,
Santiago, Chile
| | - Cristian Zambrano
- Laboratory of Cellular and Molecular Biology and Neurosciences, Millennium Institute for Advanced Studies in
Cell Biology and Biotechnology (CBB), Millennium Building, Las Encinas 3370, Ñuñoa, Santiago, Chile
- Department of Neurological Sciences, Faculty of Medicine, University of Chile, Salvador 486, 750-0922 Providencia,
Santiago, Chile
| | - Ricardo B. Maccioni
- Laboratory of Cellular and Molecular Biology and Neurosciences, Millennium Institute for Advanced Studies in
Cell Biology and Biotechnology (CBB), Millennium Building, Las Encinas 3370, Ñuñoa, Santiago, Chile
- Department of Neurological Sciences, Faculty of Medicine, University of Chile, Salvador 486, 750-0922 Providencia,
Santiago, Chile
- *Ricardo B. Maccioni:
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Bhattacharyya R, Kovacs DM. ACAT inhibition and amyloid beta reduction. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:960-5. [PMID: 20398792 DOI: 10.1016/j.bbalip.2010.04.003] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/26/2010] [Revised: 04/01/2010] [Accepted: 04/02/2010] [Indexed: 12/26/2022]
Abstract
Alzheimer's disease (AD) is a devastating neurodegenerative disorder. Accumulation and deposition of the beta-amyloid (Abeta) peptide generated from its larger amyloid precursor protein (APP) is one of the pathophysiological hallmarks of AD. Intracellular cholesterol was shown to regulate Abeta production. Recent genetic and biochemical studies indicate that not only the amount, but also the distribution of intracellular cholesterol is critical to regulate Abeta generation. Acyl-coenzyme A: cholesterol acyl-transferase (ACAT) is a family of enzymes that regulates the cellular distribution of cholesterol by converting membrane cholesterol into hydrophobic cholesteryl esters for cholesterol storage and transport. Using pharmacological inhibitors and transgenic animal models, we and others have identified ACAT1 as a potential therapeutic target to lower Abeta generation and accumulation. Here we discuss data focusing on ACAT inhibition as an effective strategy for the prevention and treatment of AD.
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Affiliation(s)
- Raja Bhattacharyya
- Neurobiology of Disease Laboratory, Genetics and Aging Research Unit, MassGeneral Institute for Neurodegenerative Diseases (MIND), Massachusetts General Hospital, Harvard Medical School, Charlestown, MA 02129, USA
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Burns MP, Rebeck GW. Intracellular cholesterol homeostasis and amyloid precursor protein processing. Biochim Biophys Acta Mol Cell Biol Lipids 2010; 1801:853-9. [PMID: 20304094 DOI: 10.1016/j.bbalip.2010.03.004] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/02/2010] [Revised: 03/03/2010] [Accepted: 03/04/2010] [Indexed: 01/11/2023]
Abstract
Many preclinical and clinical studies have implied a role for cholesterol in the pathogenesis of Alzheimer's disease (AD). In this review we will discuss the movement of intracellular cholesterol and how normal distribution, transport, and export of cholesterol are vital for regulation of the AD related protein, Abeta. We focus on cholesterol distribution in the plasma membrane, transport through the endosomal/lysosomal system, control of cholesterol intracellular signaling at the endoplasmic reticulum and Golgi, the HMG-CoA reductase pathway and finally export of cholesterol from the cell.
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Affiliation(s)
- Mark P Burns
- Georgetown University Medical Center, Department of Neuroscience, Washington, DC 20057, USA.
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Panza F, Solfrizzi V, Frisardi V, Capurso C, D'Introno A, Colacicco AM, Vendemiale G, Capurso A, Imbimbo BP. Disease-modifying approach to the treatment of Alzheimer's disease: from alpha-secretase activators to gamma-secretase inhibitors and modulators. Drugs Aging 2010; 26:537-55. [PMID: 19655822 DOI: 10.2165/11315770-000000000-00000] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/13/2022]
Abstract
In the last decade, advances in understanding the neurobiology of Alzheimer's disease (AD) have translated into an increase in clinical trials assessing various potential AD treatments. At present, drugs used for the treatment of AD only slightly delay the inevitable symptomatic progression of the disease and do not affect the main neuropathological hallmarks of the disease, i.e. senile plaques and neurofibrillary tangles. Brain accumulation of oligomeric species of beta-amyloid (A beta) peptides, the principal components of senile plaques, is believed to play a crucial role in the development of AD. Based on this hypothesis, huge efforts are being made to identify drugs able to interfere with proteases regulating A beta formation from amyloid precursor protein (APP). Compounds that stimulate alpha-secretase, the enzyme responsible for non-amyloidogenic metabolism of APP, are being developed and one of these, EHT-0202, has recently commenced evaluation in a phase II study. The discovery of inhibitors of beta-secretase (memapsin-2, beta-amyloid cleaving enzyme-1 [BACE-1]), the enzyme that regulates the first step of amyloidogenic APP metabolism, has proved to be particularly difficult because of inherent medicinal chemistry issues and only one compound (CTS-21166) has proceeded to clinical testing. Conversely, several compounds that inhibit gamma-secretase, the pivotal enzyme that generates A beta, have been identified, the most advanced being LY-450139 (semagacestat), presently in phase III clinical development. There has been considerable disappointment over the failure of a phase III study of tarenflurbil, a compound believed to modulate the activity of gamma-secretase, after encouraging phase II findings. Nevertheless, other promising gamma-secretase modulators are being developed and are approaching clinical testing. All these therapeutic approaches increase the hope of slowing the rate of decline in patients with AD and modifying the natural history of this devastating disease within the next 5 years.
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Affiliation(s)
- Francesco Panza
- Department of Geriatrics, Center for Aging Brain, Memory Unit, University of Bari, Bari, Italy.
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Mahmood A, Goussev A, Kazmi H, Qu C, Lu D, Chopp M. Long-term benefits after treatment of traumatic brain injury with simvastatin in rats. Neurosurgery 2009; 65:187-91; discussion 191-2. [PMID: 19574841 DOI: 10.1227/01.neu.0000343540.24780.d6] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023] Open
Abstract
OBJECTIVE This study was designed to investigate the long-term effects of simvastatin treatment after traumatic brain injury (TBI) in rats. METHODS Adult female Wistar rats (n = 24) were injured with controlled cortical impact and divided into 3 groups. The first 2 groups were treated with simvastatin (0.5 or 1.0 mg/kg) administered orally for 14 days starting 1 day after TBI. The third group (control) received phosphate-buffered saline orally for 14 days. Neurological functional outcome was measured with modified neurological severity scores performed 1 day before TBI; on days 1, 4, 7, 14 after TBI; and biweekly thereafter. All animals were sacrificed 3 months after TBI. Brain tissues of half of the animals were processed for preparation of paraffin-embedded sections for immunohistological studies. The remaining half were frozen for enzyme-linked immunosorbent assay studies for quantification of brain-derived neurotrophic factor (BDNF) in the hippocampus and cortex. RESULTS The results showed that both doses of simvastatin significantly improved functional outcome compared with the control, with no difference between the 2 doses. Simvastatin treatment of 1.0 mg/kg increased the number of morphologically intact neurons in the hippocampus, but treatment of 0.5 mg/kg had no significant effect. Enzyme-linked immunosorbent assay studies showed that 0.5 mg/kg simvastatin significantly increased BDNF levels within the hippocampus, but 1.0 mg/kg had no significant effect. Neither dose had any effect on BDNF levels within the cortex. CONCLUSION Simvastatin treatment provides long-lasting functional improvement after TBI in rats. It also enhances neuronal survival in the hippocampus and increases BDNF levels in the hippocampus secondary to simvastatin treatment.
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Affiliation(s)
- Asim Mahmood
- Department of Neurosurgery, Henry Ford Health System, Detroit, Michigan, USA.
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31
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Lanctôt KL, Rajaram RD, Herrmann N. Therapy for Alzheimer's Disease: How Effective are Current Treatments? Ther Adv Neurol Disord 2009; 2:163-80. [PMID: 21179526 PMCID: PMC3002627 DOI: 10.1177/1756285609102724] [Citation(s) in RCA: 69] [Impact Index Per Article: 4.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
Abstract
Available symptomatic therapies for the treatment of Alzheimer's disease (AD) have been based on known neurotransmitter dysfunctions associated with the illness. The second-generation cholinesterase inhibitors and the N-methyl D-aspartate receptor antagonist memantine have been widely prescribed and studied. Meta-analyses of these therapies were reviewed, focusing on effectiveness and tolerability. Although many of the meta-analyses demonstrate statistically significant improvements, some question if these benefits are sufficient to justify their current widespread and protracted use. This has spurred the development of new disease-modifying therapies that aim to have a greater impact on this debilitating illness.
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Affiliation(s)
- Krista L Lanctôt
- Department of Psychiatry, Sunnybrook Health Sciences Centre, Toronto, ON, Canada
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32
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Fan J, Donkin J, Wellington C. Greasing the wheels of Abeta clearance in Alzheimer's disease: the role of lipids and apolipoprotein E. Biofactors 2009; 35:239-48. [PMID: 19472365 DOI: 10.1002/biof.37] [Citation(s) in RCA: 78] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/10/2022]
Abstract
Although apolipoprotein E (apoE) is the most common genetic risk factor for Alzheimer's Disease (AD), how apoE participates in AD pathogenesis remains incompletely understood. ApoE is also the major carrier of lipids in the brain. Here, we review studies showing that the lipidation status of apoE influences the metabolism of Abeta peptides, which accumulate as amyloid deposits in the neural parenchyma and cerebrovasculature. One effect of apoE is to inhibit the transport of Abeta across the blood-brain-barrier (BBB), particularly when apoE is lipidated. A second effect is to facilitate the proteolytic degradation of Abeta by neprilysin and insulin degrading enzyme (IDE), which is enhanced when apoE is lipidated. We also describe how apoE becomes lipidated and how this impacts Abeta metabolism. Specifically, genetic loss of the cholesterol transporter ABCA1 impairs apoE lipidation and promotes amyloid deposition in AD mouse models. ABCA1 catalyses the ATP-dependent transport of cholesterol and phospholipids from the plasma membrane to lipid-free apolipoproteins including apoE. Conversely, selective overexpression of ABCA1 increases apoE lipidation in the central nervous system (CNS) and eliminates the formation of amyloid plaques in vivo. Deficiency of Liver-X-Receptors (LXRs), transcription factors that stimulate ABCA1 and apoE expression, exacerbates AD pathogenesis in vivo, whereas treatment of AD mice with synthetic LXR agonists reduces amyloid load and improves cognitive performance. These studies provide new insights into the mechanisms by which apoE affects Abeta metabolism, and offer opportunities to develop novel therapeutic approaches to reduce the leading cause of dementia in the elderly.
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Affiliation(s)
- Jianjia Fan
- Department of Pathology and Laboratory Medicine, Vancouver British Columbia, Vancouver, BC, Canada
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Jones RW, Kivipelto M, Feldman H, Sparks L, Doody R, Waters DD, Hey-Hadavi J, Breazna A, Schindler RJ, Ramos H. The Atorvastatin/Donepezil in Alzheimer's Disease Study (LEADe): design and baseline characteristics. Alzheimers Dement 2008; 4:145-53. [PMID: 18631958 DOI: 10.1016/j.jalz.2008.02.001] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/28/2022]
Abstract
BACKGROUND Growing evidence suggests that elevated cholesterol levels in mid-life are associated with increased risk of developing Alzheimer's disease (AD), and that statins might have a protective effect against AD and dementia. The Lipitor's Effect in Alzheimer's Dementia (LEADe) study tests the hypothesis that a statin (atorvastatin 80 mg daily) will provide a benefit on the course of mild to moderate AD in patients receiving background therapy of a cholinesterase inhibitor (donepezil 10 mg daily). METHODS This is an international, multicenter, double-blind, randomized, parallel-group study with a double-blind randomized withdrawal phase of patients with mild to moderate AD (Mini-Mental State Examination [MMSE] score, 13 to 25). Inclusion criteria included age 50 to 90 years, receiving donepezil 10 mg for at least 3 months before randomization, and low-density lipoprotein cholesterol levels (LDL-C) 2.5 to 3.5 mmol/L (95 to 195 mg/dL). Co-primary end points are changes in AD Assessment Scale-cognitive subscale (ADAS-cog) and AD Cooperative Study-Clinical Global Impression of Change (ADCS-CGIC) scale scores. A confirmatory end point is rate of change in whole brain and hippocampal volumes in patients who enrolled in the magnetic resonance imaging substudy. RESULTS Enrollment of 641 subjects is complete. The baseline mean data are age 74 +/- 8 years, 53% women, MMSE 22 +/- 3, ADAS-cog 23 +/- 10, AD Functional Assessment and Change Scale (ADFACS) 13 +/- 9, Neuropsychiatric Inventory (NPI) 10 +/- 11, and Clinical Dementia Rating-Sum of Boxes (CDR-SB) 6 +/- 3. Mean prior donepezil treatment was 409 +/- 407 days. Mean baseline lipid levels are total cholesterol 5.8 +/- 0.8 mmol/L (224 +/- 33 mg/dL), LDL-C 3.7 +/- 0.7 mmol/L (143 +/- 26 mg/dL), triglycerides 1.5 +/- 0.7 mmol/L (132 +/- 64 mg/dL), and high-density lipoprotein cholesterol 1.6 +/- 0.5 mmol/L (64 +/- 18 mg/dL). CONCLUSIONS LEADe will report in 2008 and is expected to provide a more definitive evaluation of the potential for statins in the treatment of people with AD.
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Affiliation(s)
- Roy W Jones
- RICE (The Research Institute for the Care of Older People), Royal United Hospital, Bath, United Kingdom.
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Aluise CD, Sowell RA, Butterfield DA. Peptides and proteins in plasma and cerebrospinal fluid as biomarkers for the prediction, diagnosis, and monitoring of therapeutic efficacy of Alzheimer's disease. Biochim Biophys Acta Mol Basis Dis 2008; 1782:549-58. [PMID: 18760351 DOI: 10.1016/j.bbadis.2008.07.008] [Citation(s) in RCA: 64] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/10/2008] [Revised: 07/22/2008] [Accepted: 07/24/2008] [Indexed: 02/07/2023]
Abstract
Alzheimer's disease (AD) affects millions of persons worldwide. Earlier detection and/or diagnosis of AD would permit earlier intervention, which conceivably could delay progression of this dementing disorder. In order to accomplish this goal, reliable and specific biomarkers are needed. Biomarkers are multidimensional and have the potential to aid in various facets of AD such as diagnostic prediction, assessment of disease stage, discrimination from normally cognitive controls as well as other forms of dementia, and therapeutic efficacy of AD drugs. To date, biomarker research has focused on plasma and cerebrospinal fluid (CSF), two bodily fluids believed to contain the richest source of biomarkers for AD. CSF is the fluid surrounding the central nervous system (CNS), and is the most indicative obtainable fluid of brain pathology. Blood plasma contains proteins that affect brain processes from the periphery, as well as proteins/peptides exported from the brain; this fluid would be ideal for biomarker discovery due to the ease and non-invasive process of sample collection. However, it seems reasonable that biomarker discovery will result in combinations of CSF, plasma, and other fluids such as urine, to serve the aforementioned purposes. This review focuses on proteins and peptides identified from CSF, plasma, and urine that may serve as biomarkers in AD.
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Affiliation(s)
- Christopher D Aluise
- Department of Chemistry, Center of Membrane Sciences, and Sanders-Brown Center on Aging, University of Kentucky, Lexington, KY 40506-0055, USA
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Fillit H, Nash DT, Rundek T, Zuckerman A. Cardiovascular risk factors and dementia. ACTA ACUST UNITED AC 2008; 6:100-18. [DOI: 10.1016/j.amjopharm.2008.06.004] [Citation(s) in RCA: 153] [Impact Index Per Article: 9.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 03/10/2008] [Indexed: 12/19/2022]
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Wu H, Lu D, Jiang H, Xiong Y, Qu C, Li B, Mahmood A, Zhou D, Chopp M. Simvastatin-mediated upregulation of VEGF and BDNF, activation of the PI3K/Akt pathway, and increase of neurogenesis are associated with therapeutic improvement after traumatic brain injury. J Neurotrauma 2008; 25:130-9. [PMID: 18260796 DOI: 10.1089/neu.2007.0369] [Citation(s) in RCA: 239] [Impact Index Per Article: 14.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
This study was undertaken to evaluate the effect of simvastatin, a cholesterol-lowering agent, on the Akt-mediated signaling pathway and neurogenesis in the dentate gyrus (DG) of the hippocampus in rats after traumatic brain injury (TBI). Adult male Wistar rats were divided into three groups: (1) sham group (n = 8); (2) saline control group (n = 40); and (3) simvastatin-treated group (n = 40). Controlled cortical impact (CCI) injury was performed over the left parietal lobe. Simvastatin was administered orally at a dose of 1 mg/kg starting at day 1 after TBI and then daily for 14 days. Bromodeoxyuridine (BrdU) was injected intraperitoneally into rats. A modified Morris Water Maze (WM) task was performed between 31 and 35 days after treatment to test spatial memory (n = 8/group). Animals were sacrificed at 1, 3, 7, 14, and 35 days after treatment (n = 8/group/time point). Western blot was utilized to investigate the changes in the Akt-mediated signaling pathway. Enzyme-linked immunosorbent assay (ELISA) analyses were employed to measure vascular endothelial growth factor (VEGF) and brain-derived neurotrophin factor (BDNF) expression. Immunohistochemical and fluorescent staining were performed to detect the BrdU- and neuronal nuclei (NeuN)/BrdU-positive cells. Our data show that simvastatin treatment increases phosphorylation of v-akt murine thymoma viral oncogene homolog (Akt), glycogen synthase kinase-3beta (GSK-3beta), and cAMP response element-binding proteins (CREB); elevates the expression of BDNF and VEGF in the DG; increases cell proliferation and differentiation in the DG; and enhances the recovery of spatial learning. These data suggest that the neurorestorative effect of simvastatin may be mediated through activation of the Akt-mediated signaling pathway, subsequently upregulating expression of growth factors and inducing neurogenesis in the DG of the hippocampus, thereby leading to restoration of cognitive function after TBI in rats.
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Affiliation(s)
- Hongtao Wu
- Department of Neurosurgery, Henry Ford Health System, Detroit, Michigan, USA
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Rebollo A, Pou J, Alegret M. Cholesterol lowering and beyond: role of statins in Alzheimer’s disease. ACTA ACUST UNITED AC 2008. [DOI: 10.2217/1745509x.4.2.171] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
Alzheimer’s disease (AD), the most common form of dementia, is a major health problem with increasing prevalence associated with the increase in life span. Unfortunately, drugs currently used to treat this disorder have only modest therapeutic efficacy. Therefore, there is an urgent need to develop new pharmacological strategies to prevent or delay the onset of AD. As it has been suggested that there is a link between cholesterol and the development of AD, one such strategy could be the inhibition of cholesterol synthesis using HMG-CoA reductase inhibitors (statins). In addition to their cholesterol-lowering properties, statins exert multiple lipid-independent (pleiotropic) effects that may explain some of their beneficial actions. The aim of this article is to summarize the current knowledge on the effects of statins on AD and the mechanisms involved, based on data from in vitro, in vivo and clinical studies, and to provide an overview of the future perspectives in this field.
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Affiliation(s)
- Alba Rebollo
- University of Barcelona & Ciber Diabetes y Enfermedades Metabólicas asociadas (CIBERDEM), Pharmacology Department, Faculty of Pharmacy & Biomedicine Institute (IBUB), Instituto de Salud Carlos III, Spain
| | - Jordi Pou
- University of Barcelona & Ciber Diabetes y Enfermedades Metabólicas asociadas (CIBERDEM), Pharmacology Department, Faculty of Pharmacy & Biomedicine Institute (IBUB), Instituto de Salud Carlos III, Spain
| | - Marta Alegret
- University of Barcelona & Ciber Diabetes y Enfermedades Metabólicas asociadas (CIBERDEM), Pharmacology Department, Faculty of Pharmacy & Biomedicine Institute (IBUB), Instituto de Salud Carlos III, Spain
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Grimm MOW, Grimm HS, Tomic I, Beyreuther K, Hartmann T, Bergmann C. Independent inhibition of Alzheimer disease beta- and gamma-secretase cleavage by lowered cholesterol levels. J Biol Chem 2008; 283:11302-11. [PMID: 18308724 DOI: 10.1074/jbc.m801520200] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022] Open
Abstract
The major molecular risk factor for Alzheimer disease so far identified is the amyloidogenic peptide Abeta(42). In addition, growing evidence suggests a role of cholesterol in Alzheimer disease pathology and Abeta generation. However, the cellular mechanism of lipid-dependent Abeta production remains unclear. Here we describe that the two enzymatic activities responsible for Abeta production, beta-secretase and gamma-secretase, are inhibited in parallel by cholesterol reduction. Importantly, our data indicate that cholesterol depletion within the cellular context inhibits both secretases additively and independently from each other. This is unexpected because the beta-secretase beta-site amyloid precursor protein cleaving enzyme and the presenilin-containing gamma-secretase complex are structurally different from each other, and these enzymes are apparently located in different subcellular compartments. The parallel and additive inhibition has obvious consequences for therapeutic research and may indicate an intrinsic cross-talk between Alzheimer disease-related amyloid precursor protein processing, amyloid precursor protein function, and lipid biology.
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Affiliation(s)
- Marcus O W Grimm
- Department of Neurology, Saarland University, Kirrbergerstrasse, 66421 Homburg/Saar, Germany
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Cholesterol Potentiates β-Amyloid-Induced Toxicity in Human Neuroblastoma Cells: Involvement of Oxidative Stress. Neurochem Res 2008; 33:1509-17. [DOI: 10.1007/s11064-008-9623-y] [Citation(s) in RCA: 34] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2007] [Accepted: 02/04/2008] [Indexed: 10/22/2022]
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van der Hilst JCH, Kluve-Beckerman B, Bodar EJ, van der Meer JWM, Drenth JPH, Simon A. Lovastatin inhibits formation of AA amyloid. J Leukoc Biol 2008; 83:1295-9. [PMID: 18285405 DOI: 10.1189/jlb.1107723] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/25/2023] Open
Abstract
Amyloid A (AA) amyloidosis is a severe complication of many chronic inflammatory disorders, including the hereditary periodic fever syndromes. However, in one of these periodic fever syndromes, the hyper IgD and periodic fever syndrome, amyloidosis is rare despite vigorous, recurring inflammation. This hereditary syndrome is caused by mutations in the gene coding for mevalonate kinase, an enzyme of the isoprenoid pathway. In this study, we used a cell culture system with human monocytes to show that inhibition of the isoprenoid pathway inhibits amyloidogenesis. Inhibition of the isoprenoid pathway by lovastatin resulted in a dose-dependent reduction of amyloid formed [53% at 10 microM (P=0.01)] compared with mononuclear cells that are exposed only to serum AA. The inhibitory effects of lovastatin are reversible by addition of farnesol but not geranylgeraniol. Farnesyl transferase inhibition also inhibited amyloidogenesis. These results implicate that the isoprenoid metabolism could be a potential target for prevention and treatment of AA amyloidosis.
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Affiliation(s)
- J C H van der Hilst
- Department of General Internal Medicine, Radboud University Nijmegen Medical Centre, Geert Grooteplein 8, P. O. Box 9101, 6500 HB, Nijmegen, The Netherlands.
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41
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Höglund K, Blennow K. Effect of HMG-CoA reductase inhibitors on beta-amyloid peptide levels: implications for Alzheimer's disease. CNS Drugs 2007; 21:449-62. [PMID: 17521225 DOI: 10.2165/00023210-200721060-00002] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
To date, a number of hypotheses of the cause of Alzheimer's disease, the most common form of dementia, have been postulated. The beta-amyloid peptide (Abeta) is the major constituent of senile plaques, which together with atrophy and neurofibrillary tangles, is the main neuropathological finding in Alzheimer's disease. It is a widely accepted theory that aggregation of Abeta into plaques is an initial event in the pathogenesis of Alzheimer's disease, driving neurodegeneration. The cholesterol hypothesis, primarily based on in vitro and animal studies, states that increased levels of cholesterol promote the production of Abeta. Furthermore, treating animals with HMG-CoA reductase inhibitors ('statins'; cholesterol-lowering agents), or adding these agents to cell culture, results in decreased production of Abeta. This 'positive' effect of statin treatment has further been verified by some, but not all, longitudinal studies where a reduced prevalence of Alzheimer's disease is seen among patients taking statins. These findings have together been interpreted to indicate that statins act via a cholesterol-dependent mechanism, reducing the production of Abeta and, hence, the risk of developing Alzheimer's disease. This review focuses on the cholesterol hypothesis of Alzheimer's disease and investigations into its validity in the clinical setting, i.e. the outcome of clinical trials where the effect of statin treatment on Abeta production has been studied. To date, the cholesterol hypothesis has not been shown to be valid in clinical trials. We hypothesise that the vascular contributions in Alzheimer's disease may be one possible mechanism for statins to interfere with the disease process and reduce the prevalence of Alzheimer's disease. We also suggest that statins may act through the inflammatory pathway. Both of these mechanistic suggestions are good candidates, supported by the literature, for the underlying mechanistic link between statin treatment and a reduced prevalence for Alzheimer's disease.
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Affiliation(s)
- Kina Höglund
- Department of Neuroscience and Physiology, Section of Psychiatry and Neurochemistry at the Sahlgrenska Academy, Göteborg University, Göteborg, Sweden.
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42
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Vuletic S, Riekse RG, Marcovina SM, Peskind ER, Hazzard WR, Albers JJ. Statins of different brain penetrability differentially affect CSF PLTP activity. Dement Geriatr Cogn Disord 2007; 22:392-8. [PMID: 16960448 DOI: 10.1159/000095679] [Citation(s) in RCA: 46] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 05/26/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND/AIMS Phospholipid transfer protein (PLTP) and apolipoprotein E (apoE) are key proteins involved in lipoprotein metabolism in the peripheral circulation and in the brain. Several epidemiological studies suggested that use of 3-hydroxyl-3-methylglutaryl-coenzyme A reductase inhibitors (statins) reduces risk of Alzheimer's disease (AD). However, the effects of statins of differing blood-brain barrier (BBB) penetrability on brain-derived molecules in cognitively normal individuals are largely unknown. METHODS To assess the effect of statins on these indices as a function of BBB penetration, cerebrospinal fluid (CSF) and plasma PLTP activity and apoE concentration were measured in cognitively intact, modestly hypercholesterolemic adults randomly allocated to treatment with either pravastatin, which does not penetrate BBB (80 mg/day, n = 13), or simvastatin, which penetrates BBB (40 mg/day, n = 10). RESULTS Simvastatin significantly increased CSF PLTP activity (p = 0.005). In contrast, pravastatin had no such effect. In the pravastatin-treated group, CSF apoE concentration decreased significantly (p = 0.026), while the simvastatin-treated group showed a tendency towards lower CSF apoE levels, with CSF apoE concentration lowered in 8 of 10 subjects. CONCLUSION Our data indicate that statins differentially affect two key lipid transfer proteins in the brain, and that effect on PLTP activity depends on statin BBB penetrability.
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Affiliation(s)
- Simona Vuletic
- Department of Medicine, University of Washington School of Medicine, Seattle, WA, USA
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43
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Fahrenholz F, Postina R. Alpha-secretase activation--an approach to Alzheimer's disease therapy. NEURODEGENER DIS 2006; 3:255-61. [PMID: 17047365 DOI: 10.1159/000095264] [Citation(s) in RCA: 44] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022] Open
Abstract
The nonamyloidogenic pathway of processing the amyloid precursor protein (APP) involves the cleavage within the amyloid-beta peptide sequence, and thus precludes amyloid-beta formation. The identification of a member of the disintegrin and metalloproteinase family, ADAM10, as an alpha-secretase that prevents plaque formation and hippocampal deficits in vivo gave us the possibility to examine the alpha-secretase as a potential target for the therapy of Alzheimer's disease. Within the priority program Cellular Mechanisms of Alzheimer's Disease, we investigated several approaches to stimulate the alpha-secretase pathway. Two protein convertases were found to be responsible for the removal of the prodomain, and for the formation of the mature enzyme with alpha-secretase activity. The cloning and characterization of the human ADAM10 promoter provided the basis to examine ADAM10 gene expression. We found a common upregulation of ADAM10, APP, and APP-like protein 2 during differentiation of neuronal cells by retinoic acid, and increased alpha-secretase cleavage of the two substrates. Other approaches for enhancing alpha-secretase activity are the reduction of cellular cholesterol and the stimulation of G protein-coupled neuropeptide receptors. Our results suggest medications and dietary regiments which enhance the nonamyloidogenic pathway of APP processing to be a valuable approach to Alzheimer's disease therapy.
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Affiliation(s)
- Falk Fahrenholz
- Institute of Biochemistry, University of Mainz, Mainz, Germany.
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Chauhan NB. Effect of aged garlic extract on APP processing and tau phosphorylation in Alzheimer's transgenic model Tg2576. JOURNAL OF ETHNOPHARMACOLOGY 2006; 108:385-94. [PMID: 16842945 DOI: 10.1016/j.jep.2006.05.030] [Citation(s) in RCA: 73] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2005] [Revised: 05/21/2006] [Accepted: 05/25/2006] [Indexed: 05/10/2023]
Abstract
Multiple components present in garlic and various garlic preparations are known to exert pleiotropic protective effects as demonstrated in various in vitro and in vivo model systems. However, garlic pleiotropy in relation to Alzheimer's pathophysiology has not been explored extensively. Current study investigated anti-amyloidogenic, anti-inflammatory and anti-tangle effects of dietary aged garlic extract (AGE) (2%) and compared with its prominent constituents, i.e. S-allyl-cysteine (SAC) (20 mg/kg) and di-allyl-disulfide (DADS) (20 mg/kg) in Alzheimer's Swedish double mutant mouse model (Tg2576). Possible cholesterol-dependent and cholesterol-independent mechanisms of actions of AGE, SAC and DADS in exerting anti-amyloidogenic, anti-inflammatory and anti-tangle effects are discussed. Finally, ameliorative effects of dietary interventions were found to be in the order of AGE>SAC>DADS. If validated pre-clinically, dietary intervention with herbal alternative such as AGE having pleiotropic useful properties and least adverse effects may provide greater therapeutic benefit over a single-ingredient synthetic pharmaceutical drug having serious side effects in treating Alzheimer's disease.
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Affiliation(s)
- Neelima B Chauhan
- Department of Anesthesiology, University of Illinois at Chicago, USA.
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45
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Abstract
Statins inhibit 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase, which initiates the syntheses of cholesterol and isoprenoid lipids that are needed to provide amyloid peptides for the amyloid cascade. This cascade is believed to induce sporadic or late-onset Alzheimer's disease, which accounts for 90 - 95% of Alzheimer's disease sufferers. Cholesterol is also the prime driver of cerebrovascular disease that (along with amyloid peptides) increasingly appears to be linked to the cognitive deterioration of Alzheimer's disease. Cholesterol is needed to make the lipid rafts that are the platforms for isoprenoid-dependent assembly and activation of raftophilic beta- and gamma-secretases that work in tandem to excise dangerous 40 and 42 amino acid amyloid-beta (Abeta) fragments from amyloid precursor protein, the transmembrane amyloid precursor glycoprotein. When they are excessively produced and can no longer be effectively destroyed or otherwise cleared from the hypoperfused ageing brain, the Abeta42 fragments released from the active synaptic terminals of normally busy neurons (and from stressed neurons unsuccessfully trying to proliferate and producing disruptive tangles of hyperphosphorylated tau-proteins) aggregate into neuritic plaques, which activate glial cells. The pro-inflammatory cytokines and growth factors from the glial cells further damage and kill neurons. As statins strike at several parts of the Alzheimer's disease mechanism (such as the infliction of cholesterol-dependent cerebrovascular damage) by inhibiting HMG-CoA reductase, their long-term use (starting as early as possible during Alzheimer's disease development) should slow or even prevent the progression of Alzheimer's disease. Indeed, there is some evidence of a significantly reduced incidence of Alzheimer's disease among people who have been using statins to reduce hypercholesterolaemia and its cardiovascular effects. To be certain of this, there must be more multi-year trials to specifically assess the effects of statins on sporadic Alzheimer's disease.
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Affiliation(s)
- James F Whitfield
- Institute for Biological Sciences, National Research Council of Canada, Building M-54, Montreal Road Campus, Ottawa, Ontario, K1A 0R6, Canada
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46
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Hoyer S, Riederer P. Alzheimer disease--no target for statin treatment. A mini review. Neurochem Res 2006; 32:695-706. [PMID: 17063393 DOI: 10.1007/s11064-006-9168-x] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/07/2006] [Accepted: 09/11/2006] [Indexed: 10/24/2022]
Abstract
Nosologically, Alzheimer disease (AD) is not a single disorder. A minority of around 400 families worldwide can be grouped as hereditary in origin, whereas the majority of all Alzheimer cases (approx. 25 million worldwide) are sporadic in origin. In the pathophysiology of the latter type, a number of susceptibility genes contribute to the disease among which are allelic abnormalities of the apolipoprotein E4 gene pointing to a link between disturbed cholesterol metabolism and sporadic AD. Cholesterol is a main component of membrane composition enriched in microdomains and is functionally linked to the proteolytic processing of amyloid precursor protein (APP). In sporadic AD, a marked diminution of both membrane phospholipids and cholesterol has been found. Evidence has been provided that high plasma cholesterol may protect from AD. In contrast to these well documented abnormalities observed in AD patients, it was assumed that an elevated cholesterol concentration might favour the generation of beta-amyloid and, thus, AD. However, a series of in vitro-and in vivo-studies did not provide evidence for the assumption that an enhanced cholesterol concentration increased betaA4-production. A harsh reduction of membrane cholesterol only caused a "beneficial" effect of APP metabolism. However, this experimentally induced condition may not be compatible to sporadic AD. The application of statins in sporadic AD did not yield results to assume that this therapeutic strategy may prevent or treat successfully sporadic AD.
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Affiliation(s)
- Siegfried Hoyer
- Department of Pathology, University of Heidelberg, Im Neuenheimer Feld 220/221, D-69120 Heidelberg, Germany.
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47
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Ito MK, Talbert RL, Tsimikas S. Statin-associated pleiotropy: possible beneficial effects beyond cholesterol reduction. Pharmacotherapy 2006; 26:85S-97S; discussion 98S-101S; quiz 106S-108S. [PMID: 16803418 DOI: 10.1592/phco.26.7part2.85s] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/19/2023]
Abstract
Because elevated serum cholesterol levels are strongly associated with coronary heart disease, cholesterol reduction by 3-hydroxy-3-methylglutaryl coenzyme A reductase inhibitors (or statins) has been assumed to be the predominant, if not the only, mechanism underlying the beneficial effects of these drugs in cardiovascular diseases. Subgroup analyses of large clinical trials, however, have suggested that the beneficial effects of statins may extend to mechanisms beyond cholesterol reduction. Indeed, recent experimental and clinical evidence indicates that some of the cholesterol-independent or "pleiotropic" effects of statins may be mediated through improving or restoring endothelial function, enhancing the stability of atherosclerotic plaques, and decreasing oxidative stress and vascular inflammation.
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Affiliation(s)
- Matthew K Ito
- University of California, San Diego School of Medicine, La Jolla, California, USA
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Masters CL, Cappai R, Barnham KJ, Villemagne VL. Molecular mechanisms for Alzheimer's disease: implications for neuroimaging and therapeutics. J Neurochem 2006; 97:1700-25. [PMID: 16805778 DOI: 10.1111/j.1471-4159.2006.03989.x] [Citation(s) in RCA: 158] [Impact Index Per Article: 8.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/05/2023]
Abstract
Alzheimer's disease is a progressive neurodegenerative disorder characterised by the gradual onset of dementia. The pathological hallmarks of the disease are beta-amyloid (Abeta) plaques, neurofibrillary tangles, synaptic loss and reactive gliosis. The current therapeutic effort is directed towards developing drugs that reduce Abeta burden or toxicity by inhibiting secretase cleavage, Abeta aggregation, Abeta toxicity, Abeta metal interactions or by promoting Abeta clearance. A number of clinical trials are currently in progress based on these different therapeutic strategies and they should indicate which, if any, of these approaches will be efficacious. Current diagnosis of Alzheimer's disease is made by clinical, neuropsychologic and neuroimaging assessments. Routine structural neuroimaging evaluation with computed tomography and magnetic resonance imaging is based on non-specific features such as atrophy, a late feature in the progression of the disease, hence the crucial importance of developing new approaches for early and specific recognition at the prodromal stages of Alzheimer's disease. Functional neuroimaging techniques such as functional magnetic resonance imaging, magnetic resonance spectroscopy, positron emission tomography and single photon emission computed tomography, possibly in conjunction with other related Abeta biomarkers in plasma and CSF, could prove to be valuable in the differential diagnosis of Alzheimer's disease, as well as in assessing prognosis. With the advent of new therapeutic strategies there is increasing interest in the development of magnetic resonance imaging contrast agents and positron emission tomography and single photon emission computed tomography radioligands that will permit the assessment of Abeta burden in vivo.
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Affiliation(s)
- Colin L Masters
- Department of Pathology, The University of Melbourne, VIC, Australia.
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49
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Höglund K, Wallin A, Blennow K. Effect of statins on beta-amyloid metabolism in humans: potential importance for the development of senile plaques in Alzheimer's disease. Acta Neurol Scand 2006; 185:87-92. [PMID: 16866916 DOI: 10.1111/j.1600-0404.2006.00691.x] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
According to the amyloid cascade hypothesis, both familial and sporadic Alzheimer's disease (AD) is caused by the toxic effect of over-production and/or aggregation of beta-amyloid (Abeta). Recent cell and animal studies have linked the production of Abeta to high levels of cholesterol and the use of statins, compounds inhibiting the de novo synthesis of cholesterol. Epidemiological studies have also supported such linkage by showing a reduced prevalence of AD for subjects taking statins. A limited number of clinical studies have been published trying to elucidate the effect of statin treatment on amyloid precursor protein (APP) processing and metabolism of brain cholesterol in AD in humans and this review focuses on the current state of these clinical studies. The results are contradictory, but the overall interpretation suggests that statin treatment probably does not have a direct impact through lowering of cholesterol on the APP processing and Abeta production in humans. To confirm this, further clinical studies needs to be performed with extended treatment periods and where several parameters (lipid profile, lipoproteins, sterols, biomarkers related to AD and APP metabolites) are analyzed, both in the cerebrospinal fluid and plasma. The pleiotropic effects of statins should be investigated further. One approach is presented in this review.
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Affiliation(s)
- K Höglund
- Section of Experimental Neurochemistry, Institute of Clinical Neuroscience, Göteborg University, Sweden.
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50
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Martins IJ, Hone E, Foster JK, Sünram-Lea SI, Gnjec A, Fuller SJ, Nolan D, Gandy SE, Martins RN. Apolipoprotein E, cholesterol metabolism, diabetes, and the convergence of risk factors for Alzheimer's disease and cardiovascular disease. Mol Psychiatry 2006; 11:721-36. [PMID: 16786033 DOI: 10.1038/sj.mp.4001854] [Citation(s) in RCA: 231] [Impact Index Per Article: 12.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 02/08/2023]
Abstract
High fat diets and sedentary lifestyles are becoming major concerns for Western countries. They have led to a growing incidence of obesity, dyslipidemia, high blood pressure, and a condition known as the insulin-resistance syndrome or metabolic syndrome. These health conditions are well known to develop along with, or be precursors to atherosclerosis, cardiovascular disease, and diabetes. Recent studies have found that most of these disorders can also be linked to an increased risk of Alzheimer's disease (AD). To complicate matters, possession of one or more apolipoprotein E epsilon4 (APOE epsilon4) alleles further increases the risk or severity of many of these conditions, including AD. ApoE has roles in cholesterol metabolism and Abeta clearance, both of which are thought to be significant in AD pathogenesis. The apparent inadequacies of ApoE epsilon4 in these roles may explain the increased risk of AD in subjects carrying one or more APOE epsilon4 alleles. This review describes some of the physiological and biochemical changes that the above conditions cause, and how they are related to the risk of AD. A diversity of topics is covered, including cholesterol metabolism, glucose regulation, diabetes, insulin, ApoE function, amyloid precursor protein metabolism, and in particular their relevance to AD. It can be seen that abnormal lipid, cholesterol and glucose metabolism are consistently indicated as central in the pathophysiology, and possibly the pathogenesis of AD. As diagnosis of mild cognitive impairment and early AD are becoming more reliable, and as evidence is accumulating that health conditions such as diabetes, obesity, and coronary artery disease are risk factors for AD, appropriate changes to diets and lifestyles will likely reduce AD risk, and also improve the prognosis for people already suffering from such conditions.
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Affiliation(s)
- I J Martins
- Alzheimer's and Ageing, School of Biomedical and Sports Science, Edith Cowan University, Perth, WA, Australia
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