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Fazelinejad H, Zahedi E, Khadivi M. Altering plasma lipids and liver enzyme activities via hippocampal injections of hen Lysozyme amyloid aggregates in an Alzheimer's disease mouse model: Insights into the therapeutic role of Bis (Indolyl) phenylmethane. Neurosci Lett 2024; 833:137825. [PMID: 38768939 DOI: 10.1016/j.neulet.2024.137825] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/19/2023] [Revised: 05/06/2024] [Accepted: 05/17/2024] [Indexed: 05/22/2024]
Abstract
Alzheimer's disease (AD) is a prevalent form of dementia in the elderly. There is currently no effective treatment available for this disease. Diagnosis of AD typically relies on clinical manifestations and specific biomarkers. The present study investigated the impact of inducing Alzheimer's disease (AD) in mice through the injection of lysozyme amyloids formed in the presence or absence of Bis (Indolyl) phenylmethane (BIPM) on alterations in plasma lipid profiles and liver enzyme activities. 24 adult Wistar rats were divided into control, Scopolamine, Lysozyme, BIPM groups and the blood samples were obtained from the groups for biochemical analysis. The findings of the study revealed significant changes in the plasma lipid profiles and liver enzyme markers of the Lysozyme group compared to the control group. The Lysozyme group exhibited elevated triglycerides (n = 6, P < 0.02) and LDL levels (n = 6, P < 0.02), reduced HDL (n = 6, P < 0.05) and cholesterol levels (n = 6, P < 0.02), and altered serum glutamic oxaloacetic transaminase (SGOT) level (n = 6, P < 0.05) compared to controls. While the level of serum glutamic pyruvic transaminase (SGPT) did not change significantly compared to the control. BIPM groups showed no significant changes in lipid or enzyme levels compared to controls. Overall, our research has shown that BIPM has the ability to modify the structure of HEWL aggregates, thereby improving the detrimental effects associated with AD caused by these aggregates. Analyzing lipid profiles and liver enzyme markers presents a promising avenue for targeted therapeutic approaches. These alterations observed in the plasma may potentially serve as candidate biomarkers for diagnosing this disease.
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Affiliation(s)
- Hassan Fazelinejad
- Research Core of Cognitive Sciences and Aging Studies, Research Center of Hakim Sabzevari, Hakim Sabzevari University, Sabzevar, Islamic Republic of Iran.
| | - Elham Zahedi
- Department of Physiology, School of Medicine, Tehran University of Medical Sciences, Tehran, Islamic Republic of Iran
| | - Mehdi Khadivi
- Department of Biology, Payam Noor University, 19395-4697, Tehran, Islamic Republic of Iran
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Sharif A, Mamo J, Lam V, Al-Salami H, Mooranian A, Watts GF, Clarnette R, Luna G, Takechi R. The therapeutic potential of probucol and probucol analogues in neurodegenerative diseases. Transl Neurodegener 2024; 13:6. [PMID: 38247000 PMCID: PMC10802046 DOI: 10.1186/s40035-024-00398-w] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2023] [Accepted: 01/07/2024] [Indexed: 01/23/2024] Open
Abstract
Neurodegenerative disorders present complex pathologies characterized by various interconnected factors, including the aggregation of misfolded proteins, oxidative stress, neuroinflammation and compromised blood-brain barrier (BBB) integrity. Addressing such multifaceted pathways necessitates the development of multi-target therapeutic strategies. Emerging research indicates that probucol, a historic lipid-lowering medication, offers substantial potential in the realm of neurodegenerative disease prevention and treatment. Preclinical investigations have unveiled multifaceted cellular effects of probucol, showcasing its remarkable antioxidative and anti-inflammatory properties, its ability to fortify the BBB and its direct influence on neural preservation and adaptability. These diverse effects collectively translate into enhancements in both motor and cognitive functions. This review provides a comprehensive overview of recent findings highlighting the efficacy of probucol and probucol-related compounds in the context of various neurodegenerative conditions, including Alzheimer's disease, Parkinson's disease, Huntington's disease, and cognitive impairment associated with diabetes.
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Affiliation(s)
- Arazu Sharif
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - John Mamo
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
- Perron Institute for Neurological and Translational Research, Perth, WA, Australia
| | - Virginie Lam
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
- School of Public Health, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - Hani Al-Salami
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - Armin Mooranian
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - Gerald F Watts
- School of Medicine, Faculty of Health and Medical Sciences, University of Western Australia, Perth, WA, Australia
| | - Roger Clarnette
- School of Medicine, Faculty of Health and Medical Sciences, University of Western Australia, Perth, WA, Australia
| | - Giuseppe Luna
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, Australia
| | - Ryu Takechi
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, WA, Australia.
- School of Public Health, Faculty of Health Sciences, Curtin University, Perth, WA, Australia.
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Espinosa JM, Quintero-Flórez A, Carrasquilla N, Montero E, Rodríguez-Rodríguez A, Castellano JM, Perona JS. Bioactive compounds in pomace olive oil modulate the inflammatory response elicited by postprandial triglyceride-rich lipoproteins in BV-2 cells. Food Funct 2023; 14:8987-8999. [PMID: 37740318 DOI: 10.1039/d3fo02460a] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/24/2023]
Abstract
Modulation of microglial response could be a target to reduce neuroinflammation associated with Alzheimer's disease. In this study, we propose that lipophilic bioactive molecules present in pomace olive oil (POO), transported in triglyceride-rich lipoproteins (TRLs), are able to modulate microglial high-oleic sunflower oil (HOSO, points) or pomace olive oil (POO, stripes). In order to prove this hypothesis, a randomized crossover postprandial trial was performed in 18 healthy young women. POO was assayed in opposition to high-oleic sunflower oil (HOSO), a common dietary oil which shares with POO an almost identical fatty acid composition but lacks certain biomolecules with recognized antioxidant and anti-inflammatory activities. TRLs were isolated from blood at the baseline and 2 and 4 hours postprandially and used to treat BV-2 cells to assess their ability to modulate the microglial function. We found that the intake of POO leads to the constitution of postprandial TRLs that are able to modulate the inflammatory response in microglia compared to HOSO. TRL-derived POO reduced the release of pro-inflammatory cytokines (tumor necrosis factor-α, and interleukins 1β and 6) and nitric oxide and downregulated genes codifying for these cytokines and inducible nitric oxide synthase (iNOS) in BV-2 cells. Moreover, the ingestion of POO by healthy women slightly improved glycemic control and TRL clearance throughout the postprandial phase compared to HOSO. In conclusion, we demonstrated that consuming POO results in postprandial TRLs containing lipophilic bioactive compounds capable of regulating the inflammatory response prompted by microglial activation.
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Affiliation(s)
- Juan Manuel Espinosa
- Instituto de la Grasa, Department of Food and Health, Spanish National Research Council (CSIC), Campus University Pablo de Olavide, 41013, Seville, Spain.
| | | | - Natalia Carrasquilla
- Instituto de la Grasa, Department of Food and Health, Spanish National Research Council (CSIC), Campus University Pablo de Olavide, 41013, Seville, Spain.
| | - Emilio Montero
- University Hospital Virgen del Rocío, Andalusian Regional Health Service, Seville, Spain
| | | | - José María Castellano
- Instituto de la Grasa, Department of Food and Health, Spanish National Research Council (CSIC), Campus University Pablo de Olavide, 41013, Seville, Spain.
| | - Javier S Perona
- Instituto de la Grasa, Department of Food and Health, Spanish National Research Council (CSIC), Campus University Pablo de Olavide, 41013, Seville, Spain.
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D’Alonzo ZJ, Lam V, Takechi R, Nesbit M, Vaccarezza M, Mamo JCL. Peripheral metabolism of lipoprotein-amyloid beta as a risk factor for Alzheimer's disease: potential interactive effects of APOE genotype with dietary fats. GENES & NUTRITION 2023; 18:2. [PMID: 36841786 PMCID: PMC9960179 DOI: 10.1186/s12263-023-00722-5] [Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Subscribe] [Scholar Register] [Received: 09/09/2022] [Accepted: 02/07/2023] [Indexed: 02/27/2023]
Abstract
Alzheimer's disease (AD) is a progressive neurodegenerative disorder pathologically characterized by brain parenchymal abundance of amyloid-beta (Aβ) and the accumulation of lipofuscin material that is rich in neutral lipids. However, the mechanisms for aetiology of AD are presently not established. There is increasing evidence that metabolism of lipoprotein-Aβ in blood is associated with AD risk, via a microvascular axis that features breakdown of the blood-brain barrier, extravasation of lipoprotein-Aβ to brain parenchyme and thereafter heightened inflammation. A peripheral lipoprotein-Aβ/capillary axis for AD reconciles alternate hypotheses for a vascular, or amyloid origin of disease, with amyloidosis being probably consequential. Dietary fats may markedly influence the plasma abundance of lipoprotein-Aβ and by extension AD risk. Similarly, apolipoprotein E (Apo E) serves as the primary ligand by which lipoproteins are cleared from plasma via high-affinity receptors, for binding to extracellular matrices and thereafter for uptake of lipoprotein-Aβ via resident inflammatory cells. The epsilon APOE ε4 isoform, a major risk factor for AD, is associated with delayed catabolism of lipoproteins and by extension may increase AD risk due to increased exposure to circulating lipoprotein-Aβ and microvascular corruption.
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Affiliation(s)
- Zachary J. D’Alonzo
- grid.1032.00000 0004 0375 4078Faculty of Health Sciences, Curtin Medical School, Curtin University, Perth, Western Australia Australia ,grid.1032.00000 0004 0375 4078Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia Australia
| | - Virginie Lam
- grid.1032.00000 0004 0375 4078Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia Australia ,grid.1032.00000 0004 0375 4078Faculty of Health Sciences, School of Population Health, Curtin University, Perth, Western Australia Australia
| | - Ryu Takechi
- grid.1032.00000 0004 0375 4078Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia Australia ,grid.1032.00000 0004 0375 4078Faculty of Health Sciences, School of Population Health, Curtin University, Perth, Western Australia Australia
| | - Michael Nesbit
- grid.1032.00000 0004 0375 4078Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia Australia
| | - Mauro Vaccarezza
- grid.1032.00000 0004 0375 4078Faculty of Health Sciences, Curtin Medical School, Curtin University, Perth, Western Australia Australia ,grid.1032.00000 0004 0375 4078Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia Australia
| | - John C. L. Mamo
- grid.1032.00000 0004 0375 4078Faculty of Health Sciences, Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia Australia ,grid.1032.00000 0004 0375 4078Faculty of Health Sciences, School of Population Health, Curtin University, Perth, Western Australia Australia
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Nasab AS, Noorani F, Paeizi Z, Khani L, Banaei S, Sadeghi M, Shafeghat M, Shafie M, Mayeli M, Initiative (ADNI) TADN. A Comprehensive Investigation of the Potential Role of Lipoproteins and Metabolite Profile as Biomarkers of Alzheimer's Disease Compared to the Known CSF Biomarkers. Int J Alzheimers Dis 2023; 2023:3540020. [PMID: 36936136 PMCID: PMC10019964 DOI: 10.1155/2023/3540020] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/09/2022] [Revised: 12/22/2022] [Accepted: 01/30/2023] [Indexed: 03/14/2023] Open
Abstract
Introduction While cerebrospinal fluid (CSF) core biomarkers have been considered diagnostic biomarkers for a long time, special attention has been recently dedicated to lipoproteins and metabolites that could be potentially associated with Alzheimer's disease (AD) neurodegeneration. Herein, we aimed to investigate the relationship between the levels of CSF core biomarkers including Aβ-42, TAU, and P-TAU and plasma lipoproteins and metabolites of patients with AD from the baseline cohort of the Alzheimer's Disease Neuroimaging Initiative (ADNI) database. Method Using the ADNI database, fourteen subclasses of lipoproteins as well as a number of lipids and fatty acids and low-molecular metabolites including amino acids, ketone bodies, and glycolysis-related metabolites in blood samples were measured as potential noninvasive markers, and their association with the CSF core biomarkers was statistically investigated controlling for age and gender. Results A total number of 251 AD subjects were included, among whom 71 subjects were negative for the Apo-E ε4 allele and 150 were positive. There was no significant difference between the two groups regarding cognitive assessments, CSF core biomarkers, and lipoproteins and metabolites except the level of Aβ-42 (p < 0.001) and phenylalanine (p = 0.049), which were higher in the negative group. CSF TAU and P-TAU were significantly correlated with medium and small HDL in the negative group, and with extremely large VLDL in the positive group. Our results also indicated significant correlations of metabolites including unsaturated fatty acids, glycerol, and leucine with CSF core biomarkers. Conclusion Based on our findings, a number of lipoproteins and metabolites were associated with CSF core biomarkers of AD. These correlations showed some differences in Apo-E ε4 positive and negative groups, which reminds the role of Apo-E gene status in the pathophysiology of AD development. However, further research is warranted to explore the exact association of lipoproteins and other metabolites with AD core biomarkers and pathology.
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Affiliation(s)
- Azam Sajjadi Nasab
- 1NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Fatemeh Noorani
- 1NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Zahra Paeizi
- 1NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Leila Khani
- 1NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Saba Banaei
- 1NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Mohammad Sadeghi
- 1NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
| | - Melika Shafeghat
- 1NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
- 2School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahan Shafie
- 1NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
- 2School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
| | - Mahsa Mayeli
- 1NeuroTRACT Association, Students' Scientific Research Center, Tehran University of Medical Sciences, Tehran, Iran
- 2School of Medicine, Tehran University of Medical Sciences, Tehran, Iran
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Brook ES, D'Alonzo ZJ, Lam V, Chan DC, Dhaliwal SS, Watts GF, Mamo JCL, Takechi R. Plasma Amyloid-β Homeostasis Is Associated with Body Mass Index and Weight Loss in People with Overweight and Obesity. J Alzheimers Dis 2023; 93:653-664. [PMID: 37066906 DOI: 10.3233/jad-220529] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 04/18/2023]
Abstract
BACKGROUND Obesity is linked to a higher incidence of Alzheimer's disease (AD). Studies show that plasma amyloid-β (Aβ) dyshomeostasis, particularly low 42/40 ratio indicates a heightened risk for developing AD. However, the relationship between body mass index (BMI) and circulating plasma Aβ has not been extensively studied. OBJECTIVE We hypothesized that people with a high BMI have altered plasma Aβ homeostasis compared with people with a lower BMI. We also tested whether reducing BMI by calorie-restriction could normalize plasma concentrations of Aβ. METHODS Plasma concentrations of Aβ40, Aβ42, and Aβ42/40 ratio were measured in 106 participants with BMIs classified as lean, overweight, or obese. From this cohort, twelve participants with overweight or obese BMIs entered a 12-week calorie-restriction weight loss program. We then tested whether decreasing BMI affected plasma Aβ concentrations. RESULTS Plasma Aβ42/40 ratio was 17.54% lower in participants with an obese BMI compared to lean participants (p < 0.0001), and 11.76% lower compared to participants with an overweight BMI (p < 0.0001). The weight loss regimen decreased BMI by an average of 4.02% (p = 0.0005) and was associated with a 6.5% decrease in plasma Aβ40 (p = 0.0425). However, weight loss showed negligible correlations with plasma Aβ40, Aβ42, and Aβ42/40 ratio. CONCLUSION Obesity is associated with aberrant plasma Aβ homeostasis which may be associated with an increased risk for AD. Weight loss appears to lower Aβ40, but large-scale longitudinal studies in addition to molecular studies are required to elucidate the underlying mechanisms of how obesity and weight loss influence plasma Aβ homeostasis.
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Affiliation(s)
- Emily S Brook
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, Australia
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Bentley, Australia
| | - Zachary J D'Alonzo
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, Australia
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Bentley, Australia
| | - Virginie Lam
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, Australia
- School of Population Health, Faculty of Health Sciences, Curtin University, Bentley, Australia
| | - Dick C Chan
- Medical School, University of Western Australia, Perth, Australia
| | - Satvinder S Dhaliwal
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, Australia
- Duke-NUS Medical School, National University of Singapore, Singapore
- Institute for Research in Molecular Medicine (INFORMM), Universiti Sains Malaysia, Minden, Pulau Pinang, Malaysia
- Singapore University of Social Sciences, Singapore
| | - Geraldb F Watts
- Medical School, University of Western Australia, Perth, Australia
- Cardiometabolic Service, Department of Cardiology and Internal Medicine, Royal Perth Hospital, Perth, Australia
| | - John C L Mamo
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, Australia
- School of Population Health, Faculty of Health Sciences, Curtin University, Bentley, Australia
- Perron Institute of Neurological and Translational Sciences, Nedlands, Australia
| | - Ryusuke Takechi
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Bentley, Australia
- School of Population Health, Faculty of Health Sciences, Curtin University, Bentley, Australia
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Noveir SD, Kerman BE, Xian H, Meuret C, Smadi S, Martinez AE, Johansson J, Zetterberg H, Parks BA, Kuklenyik Z, Mack WJ, Johansson JO, Yassine HN. Effect of the ABCA1 agonist CS-6253 on amyloid-β and lipoprotein metabolism in cynomolgus monkeys. Alzheimers Res Ther 2022; 14:87. [PMID: 35751102 PMCID: PMC9229758 DOI: 10.1186/s13195-022-01028-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/12/2021] [Accepted: 06/07/2022] [Indexed: 06/15/2023]
Abstract
BACKGROUND Inducing brain ATP-binding cassette 1 (ABCA1) activity in Alzheimer's disease (AD) mouse models is associated with improvement in AD pathology. The purpose of this study was to investigate the effects of the ABCA1 agonist peptide CS-6253 on amyloid-β peptides (Aβ) and lipoproteins in plasma and cerebrospinal fluid (CSF) of cynomolgus monkeys, a species with amyloid and lipoprotein metabolism similar to humans. METHODS CS-6253 peptide was injected intravenously into cynomolgus monkeys at various doses in three different studies. Plasma and CSF samples were collected at several time points before and after treatment. Levels of cholesterol, triglyceride (TG), lipoprotein particles, apolipoproteins, and Aβ were measured using ELISA, ion-mobility analysis, and asymmetric-flow field-flow fractionation (AF4). The relationship between the change in levels of these biomarkers was analyzed using multiple linear regression models and linear mixed-effects models. RESULTS Following CS-6253 intravenous injection, within minutes, small plasma high-density lipoprotein (HDL) particles were increased. In two independent experiments, plasma TG, apolipoprotein E (apoE), and Aβ42/40 ratio were transiently increased following CS-6253 intravenous injection. This change was associated with a non-significant decrease in CSF Aβ42. Both plasma total cholesterol and HDL-cholesterol levels were reduced following treatment. AF4 fractionation revealed that CS-6253 treatment displaced apoE from HDL to intermediate-density- and low density-lipoprotein (IDL/LDL)-sized particles in plasma. In contrast to plasma, CS-6253 had no effect on the assessed CSF apolipoproteins or lipids. CONCLUSIONS Treatment with the ABCA1 agonist CS-6253 appears to favor Aβ clearance from the brain.
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Affiliation(s)
- Sasan D Noveir
- Departments of Medicine and Neurology, University of Southern California, Los Angeles, CA, 90033, USA
| | - Bilal E Kerman
- Departments of Medicine and Neurology, University of Southern California, Los Angeles, CA, 90033, USA
| | - Haotian Xian
- Departments of Medicine and Neurology, University of Southern California, Los Angeles, CA, 90033, USA
| | - Cristiana Meuret
- Departments of Medicine and Neurology, University of Southern California, Los Angeles, CA, 90033, USA
| | - Sabrina Smadi
- Departments of Medicine and Neurology, University of Southern California, Los Angeles, CA, 90033, USA
| | - Ashley E Martinez
- Departments of Medicine and Neurology, University of Southern California, Los Angeles, CA, 90033, USA
| | | | - Henrik Zetterberg
- Department of Psychiatry and Neurochemistry, Institute of Neuroscience and Physiology, the, Sahlgrenska Academy at the University of Gothenburg, Mölndal, Sweden
- Clinical Neurochemistry Laboratory, Sahlgrenska University Hospital, Mölndal, Sweden
- Department of Neurodegenerative Disease, UCL Institute of Neurology, Queen Square, London, UK
- UK Dementia Research Institute at UCL, London, UK
- Hong Kong Center for Neurodegenerative Diseases, Hong Kong, China
| | - Bryan A Parks
- Centers for Disease Control and Prevention, Atlanta, GA, 30341, USA
| | | | - Wendy J Mack
- Department of Population and Public Health Sciences, University of Southern California, Los Angeles, CA, 90033, USA
| | | | - Hussein N Yassine
- Departments of Medicine and Neurology, University of Southern California, Los Angeles, CA, 90033, USA.
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Rudge JD. A New Hypothesis for Alzheimer’s Disease: The Lipid Invasion Model. J Alzheimers Dis Rep 2022; 6:129-161. [PMID: 35530118 PMCID: PMC9028744 DOI: 10.3233/adr-210299] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/01/2021] [Accepted: 02/05/2022] [Indexed: 02/07/2023] Open
Abstract
This paper proposes a new hypothesis for Alzheimer’s disease (AD)—the lipid invasion model. It argues that AD results from external influx of free fatty acids (FFAs) and lipid-rich lipoproteins into the brain, following disruption of the blood-brain barrier (BBB). The lipid invasion model explains how the influx of albumin-bound FFAs via a disrupted BBB induces bioenergetic changes and oxidative stress, stimulates microglia-driven neuroinflammation, and causes anterograde amnesia. It also explains how the influx of external lipoproteins, which are much larger and more lipid-rich, especially more cholesterol-rich, than those normally present in the brain, causes endosomal-lysosomal abnormalities and overproduction of the peptide amyloid-β (Aβ). This leads to the formation of amyloid plaques and neurofibrillary tangles, the most well-known hallmarks of AD. The lipid invasion model argues that a key role of the BBB is protecting the brain from external lipid access. It shows how the BBB can be damaged by excess Aβ, as well as by most other known risk factors for AD, including aging, apolipoprotein E4 (APOE4), and lifestyle factors such as hypertension, smoking, obesity, diabetes, chronic sleep deprivation, stress, and head injury. The lipid invasion model gives a new rationale for what we already know about AD, explaining its many associated risk factors and neuropathologies, including some that are less well-accounted for in other explanations of AD. It offers new insights and suggests new ways to prevent, detect, and treat this destructive disease and potentially other neurodegenerative diseases.
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Affiliation(s)
- Jonathan D’Arcy Rudge
- School of Biological Sciences, University of Reading, Reading, Berkshire, United Kingdom
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Lam V, Clarnette R, Francis R, Bynevelt M, Watts G, Flicker L, Orr CF, Loh P, Lautenschlager N, Reid CM, Foster JK, Dhaliwal SS, Robinson S, Corti E, Vaccarezza M, Horgan B, Takechi R, Mamo J. Efficacy of probucol on cognitive function in Alzheimer's disease: study protocol for a double-blind, placebo-controlled, randomised phase II trial (PIA study). BMJ Open 2022; 12:e058826. [PMID: 35190446 PMCID: PMC8860076 DOI: 10.1136/bmjopen-2021-058826] [Citation(s) in RCA: 7] [Impact Index Per Article: 3.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/12/2022] Open
Abstract
INTRODUCTION Preclinical, clinical and epidemiological studies support the hypothesis that aberrant systemic metabolism of amyloid beta (Aβ) in the peripheral circulation is causally related to the development of Alzheimer's disease (AD). Specifically, recent studies suggest that increased plasma concentrations of lipoprotein-Aβ compromise the brain microvasculature, resulting in extravasation and retention of the lipoprotein-Aβ moiety. The latter results in an inflammatory response and neurodegeneration ensues. Probucol, a historic cholesterol-lowering drug, has been shown in murine models to suppress lipoprotein-Aβ secretion, concomitant with maintaining blood-brain-barrier function, suppressing neurovascular inflammation and supporting cognitive function. This protocol details the probucol in Alzheimer's study, a drug intervention trial investigating if probucol has potential to attenuate cognitive decline, delay brain atrophy and reduce cerebral amyloid burden in patients with mild-to-moderate AD. METHODS AND ANALYSIS The study is a phase II, randomised, placebo-controlled, double-blind single-site clinical trial held in Perth, Australia. The target sample is 314 participants with mild-to-moderate AD. Participants will be recruited and randomised (1:1) to a 104-week intervention consisting of placebo induction for 2 weeks followed by 102 weeks of probucol (Lorelco) or placebo. The primary outcome is changed in cognitive performance determined via the Alzheimer's Disease Assessment Scales-Cognitive Subscale test between baseline and 104 weeks. Secondary outcomes measures will be the change in brain structure and function, cerebral amyloid load, quality of life, and the safety and tolerability of Lorelco, after a 104week intervention. ETHICS AND DISSEMINATION The study has been approved by the Bellberry Limited Human Research Ethics Committee (approval number: HREC2019-11-1063; Version 4, 6 October 2021). Informed consent will be obtained from participants prior to any study procedures being performed. The investigator group will disseminate study findings through peer-reviewed publications, key conferences and local stakeholder events. TRIAL REGISTRATION NUMBER Australian New Zealand Clinical Trials Registry (ACTRN12621000726853).
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Affiliation(s)
- Virginie Lam
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
| | - Roger Clarnette
- Australian Alzheimer's Research Foundation, University of Western Australia, Nedlands, Western Australia, Australia
- School of Medicine, University of Western Australia, Crawley, Western Australia, Australia
| | - Roslyn Francis
- School of Medicine, University of Western Australia, Crawley, Western Australia, Australia
- Department of Nuclear Medicine, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Michael Bynevelt
- Neurological Intervention and Imaging Service of Western Australia, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
| | - Gerald Watts
- School of Medicine, University of Western Australia, Crawley, Western Australia, Australia
- Cardiometabolic Service, Department of Cardiology and Internal Medicine, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Leon Flicker
- WA Centre for Health & Ageing, University of Western Australia, Perth, Western Australia, Australia
| | - Carolyn F Orr
- Cognitive Clinic, Royal Perth Hospital, Perth, Western Australia, Australia
| | - Poh Loh
- WA Centre for Health & Ageing, University of Western Australia, Perth, Western Australia, Australia
| | - Nicola Lautenschlager
- Academic Unit of Psychiatry of Old Age, University of Melbourne, Victoria, Victoria, Australia
- North Western Mental Health, Royal Melbourne Hospital, Parkville, Victoria, Australia
- Division of Psychiatry and WA Centre for Health and Ageing, University of Western Australia, Perth, Western Australia, Australia
| | - Christopher M Reid
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
| | - Jonathan K Foster
- Synapse Neuropsychology, Perth, Western Australia, Australia
- Faculty of Health Sciences, Curtin University, Bentley, Western Australia, Australia
- School of Paediatrics and Child Health, Faculty of Health and Medical Science, University of Western Australia, Crawley, Western Australia, Australia
| | - Satvinder S Dhaliwal
- Department of Radiation Oncology, Sir Charles Gairdner Hospital, Nedlands, Western Australia, Australia
- Duke-NUS Medical School, National University of Singapore, Singapore
- Institute for Research in Molecular Medicine, Universiti Sains Malaysia, Pulau Pinang, Malaysia
| | - Suzanne Robinson
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
| | - Emily Corti
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
| | - Mauro Vaccarezza
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Ben Horgan
- Faculty of Health Sciences, Curtin University, Bentley, Western Australia, Australia
| | - Ryusuke Takechi
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
| | - John Mamo
- Curtin Health Innovation Research Institute, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
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10
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Li Y, Li M, Zhao K, Wang Y, Tan X, Qin C, Rao Y, Sun Z, Ge L, Cao Z, Liang Y, Qiu S. Altered dynamic functional architecture in type 2 diabetes mellitus. Front Endocrinol (Lausanne) 2022; 13:1117735. [PMID: 36760808 PMCID: PMC9903314 DOI: 10.3389/fendo.2022.1117735] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 12/06/2022] [Accepted: 12/29/2022] [Indexed: 01/25/2023] Open
Abstract
INTRODUCTION Type 2 diabetes mellitus (T2DM) can accelerate cognitive decline and even dementia so that the underlying mechanism deserves further exploration. In the resting state, brain function is still changing dynamically. At present, it is still unknown whether the dynamic functional connectivity (dFC) between various brain regions is in a stable state. It is necessary to interpret brain changes from a new perspective, that is, the stability of brain architecture. METHODS In this study, we used a fixed dynamic time scale to explore the stability of dynamic functional architecture in T2DM, then the dynamic effective connectivity (dEC) was used to further explain how information flows through dynamically fluctuating brain architecture in T2DM. RESULT Two brain regions with decreased stability were found including the right supra-marginal gyrus (SMG) and the right median cingulate gyrus (MCG) in T2DM subjects. The dEC variation has increased between the left inferior frontal gyrus (IFG) and the right MCG. The direction of causal flow is from the right MCG to the left IFG. CONCLUSION The combination of stability and dEC can not only show the stability of dynamic functional architecture in brain but also reflect the fluidity of brain information, which is an innovative and interesting attempt in the field of neuroimaging. The changes of dynamic architecture in T2DM patients may present an innovative perspective and explanation for their cognitive decline.
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Affiliation(s)
- Yifan Li
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Mingrui Li
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Magnetic Resonance Imaging, Zhanjiang First Hospital of Traditional Chinese Medicine, Zhanjiang, China
| | - Kui Zhao
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yan Wang
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Xin Tan
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Chunhong Qin
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yawen Rao
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zhizhong Sun
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Limin Ge
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Zidong Cao
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
| | - Yi Liang
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- *Correspondence: Shijun Qiu, ; Yi Liang,
| | - Shijun Qiu
- First Clinical Medical College, Guangzhou University of Chinese Medicine, Guangzhou, China
- Department of Radiology, The First Affiliated Hospital of Guangzhou University of Chinese Medicine, Guangzhou, China
- *Correspondence: Shijun Qiu, ; Yi Liang,
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11
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Synthesis of human amyloid restricted to liver results in an Alzheimer disease-like neurodegenerative phenotype. PLoS Biol 2021; 19:e3001358. [PMID: 34520451 PMCID: PMC8439475 DOI: 10.1371/journal.pbio.3001358] [Citation(s) in RCA: 31] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/12/2020] [Accepted: 07/08/2021] [Indexed: 02/07/2023] Open
Abstract
Several lines of study suggest that peripheral metabolism of amyloid beta (Aß) is associated with risk for Alzheimer disease (AD). In blood, greater than 90% of Aß is complexed as an apolipoprotein, raising the possibility of a lipoprotein-mediated axis for AD risk. In this study, we report that genetic modification of C57BL/6J mice engineered to synthesise human Aß only in liver (hepatocyte-specific human amyloid (HSHA) strain) has marked neurodegeneration concomitant with capillary dysfunction, parenchymal extravasation of lipoprotein-Aß, and neurovascular inflammation. Moreover, the HSHA mice showed impaired performance in the passive avoidance test, suggesting impairment in hippocampal-dependent learning. Transmission electron microscopy shows marked neurovascular disruption in HSHA mice. This study provides causal evidence of a lipoprotein-Aß /capillary axis for onset and progression of a neurodegenerative process. It has been suggested that peripheral metabolism of amyloid-beta is associated with risk for Alzheimer’s disease. This study reveals that the expression of human amyloid exclusively in the liver induces Alzheimer’s disease-like pathologies in mice, potentially indicating a completely novel pathway of Alzheimer’s disease aetiology and therapies.
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12
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Pickering J, Wong R, Al-Salami H, Lam V, Takechi R. Cognitive Deficits in Type-1 Diabetes: Aspects of Glucose, Cerebrovascular and Amyloid Involvement. Pharm Res 2021; 38:1477-1484. [PMID: 34480263 DOI: 10.1007/s11095-021-03100-1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/05/2021] [Accepted: 08/24/2021] [Indexed: 11/28/2022]
Abstract
The evidence shows that individuals with type-1 diabetes mellitus (T1DM) are at greater risk of accelerated cognitive impairment and dementia. Although, to date the mechanisms are largely unknown. An emerging body of literature indicates that dysfunction of cerebral neurovascular network and plasma dyshomeostasis of soluble amyloid-β in association with impaired lipid metabolism are central to the onset and progression of cognitive deficits and dementia. However, the latter has not been extensively considered in T1DM. Therefore, in this review, we summarised the literature concerning altered lipid metabolism and cerebrovascular function in T1DM as an implication for potential pathways leading to cognitive decline and dementia.
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Affiliation(s)
- Justin Pickering
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia
| | - Rachel Wong
- Institute for Resilient Regions, University of Southern Queensland, Springfield Central, QLD, 4300, Australia
| | - Hani Al-Salami
- Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia.,Curtin Health Innovation Research Institute, Curtin University, Perth, WA, 6845, Australia
| | - Virginie Lam
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia.,Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia
| | - Ryu Takechi
- School of Population Health, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia. .,Curtin Medical School, Faculty of Health Sciences, Curtin University, Perth, WA, 6845, Australia.
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13
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Watts GF, Mamo JCL. Hypertriglyceridemia and Alzheimer Disease: Opening the Mind to New Therapeutic Opportunities. Clin Chem 2021; 67:6-8. [PMID: 33418571 DOI: 10.1093/clinchem/hvaa294] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2020] [Accepted: 10/29/2020] [Indexed: 11/13/2022]
Affiliation(s)
- Gerald F Watts
- School of Medicine, Faculty of Health and Medical Sciences, University of Western Australia, Perth, Western Australia, Australia.,Department of Cardiology, Lipid Disorders Clinic, Cardiometabolic Services, Royal Perth Hospital, Perth, Western Australia, Australia
| | - John C L Mamo
- Curtin Health Innovation Research Institute, Curtin University, Perth, Western Australia, Australia.,School of Public Health, Faculty of Health Sciences, Curtin University, Perth, Western Australia, Australia
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14
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Stojanovic F, Taktek M, Khieu NH, Huang J, Jiang S, Rennie K, Chakravarthy B, Costain WJ, Cuperlovic-Culf M. NMR analysis of the correlation of metabolic changes in blood and cerebrospinal fluid in Alzheimer model male and female mice. PLoS One 2021; 16:e0250568. [PMID: 33970919 PMCID: PMC8109765 DOI: 10.1371/journal.pone.0250568] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/30/2020] [Accepted: 04/09/2021] [Indexed: 11/18/2022] Open
Abstract
The development of effective therapies as well as early, molecular diagnosis of Alzheimer's disease is impeded by the lack of understanding of the underlying pathological mechanisms. Metabolomics studies of body fluids as well as brain tissues have shown major changes in metabolic profiles of Alzheimer's patients. However, with analysis performed at the late stages of the disease it is not possible to distinguish causes and consequence. The mouse model APP/PS1 expresses a mutant amyloid precursor protein resulting in early Amyloid β (Aβ) accumulation as well as many resulting physiological changes including changes in metabolic profile and metabolism. Analysis of metabolic profile of cerebrospinal fluid (CSF) and blood of APP/PS1 mouse model can provide information about metabolic changes in these body fluids caused by Aβ accumulation. Using our novel method for analysis of correlation and mathematical ranking of significant correlations between metabolites in CSF and blood, we have explored changes in metabolite correlation and connectedness in APP/PS1 and wild type mice. Metabolites concentration and correlation changes in CSF, blood and across the blood brain barrier determined in this work are affected by the production of amyloid plaque. Metabolite changes observed in the APP/PS1 mouse model are the response to the mutation causing plaque formation, not the cause for the plaque suggesting that they are less relevant in the context of early treatment and prevention then the metabolic changes observed only in humans.
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Affiliation(s)
- Filip Stojanovic
- National Research Council of Canada, Digital Technologies Research Centre, Ottawa, Canada
| | - Mariam Taktek
- National Research Council of Canada, Digital Technologies Research Centre, Ottawa, Canada
| | - Nam Huan Khieu
- National Research Council of Canada, Human Health Therapeutics Research Centre, Ottawa, Canada
| | - Junzhou Huang
- National Research Council of Canada, Human Health Therapeutics Research Centre, Ottawa, Canada
| | - Susan Jiang
- National Research Council of Canada, Human Health Therapeutics Research Centre, Ottawa, Canada
| | - Kerry Rennie
- National Research Council of Canada, Human Health Therapeutics Research Centre, Ottawa, Canada
| | - Balu Chakravarthy
- National Research Council of Canada, Human Health Therapeutics Research Centre, Ottawa, Canada
| | - Will J. Costain
- National Research Council of Canada, Human Health Therapeutics Research Centre, Ottawa, Canada
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15
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Agarwal M, Khan S. Plasma Lipids as Biomarkers for Alzheimer's Disease: A Systematic Review. Cureus 2020; 12:e12008. [PMID: 33457117 PMCID: PMC7797449 DOI: 10.7759/cureus.12008] [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: 10/23/2020] [Accepted: 12/10/2020] [Indexed: 12/22/2022] Open
Abstract
Alzheimer's disease (AD) is caused by several risk factors leading to dementia. It's diagnosis usually depends on clinical presentation and certain biomarkers in the cerebrospinal fluid (CSF). The brain has a high content of cholesterol and the metabolism of cholesterol in the brain can be associated with beta-amyloid plaques formation, which is seen in Alzheimer's disease. Given these implications, we studied if plasma lipid levels can vary in Alzheimer's disease and if these can be used as biomarkers to diagnose and predict the progression of Alzheimer's disease. Certain mutations in the brain cholesterol transport receptors and proteins and their association with Alzheimer's were also studied. This systematic review abides by the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA) guidelines. We searched multiple databases, such as Pubmed, Google Scholar, Pubmed central, ScienceDirect, Web of Science, and Medline with the help of keywords like Alzheimer's disease, cognitive impairment, plasma lipid biomarkers, cholesterol, brain cholesterol metabolism separately and in combination with each other. We collected 49 quality appraised articles on the association between plasma lipids and Alzheimer's disease and the genetic mutations in alleles related to cholesterol metabolism and Alzheimer's disease by applying the inclusion and exclusion criteria. Based on the finding of the studies reviewed, we found an association between plasma lipids, polymorphisms in genes associated with cholesterol transport, and Alzheimer's disease. Increased serum low-density lipoprotein (LDL-C), triglycerides (TG), total cholesterol (TC), sphingolipids, 24S hydroxycholesterol (24S-HC), 27O hydroxycholesterol (27O-HC) was associated with Alzheimer's. Decreased high-density lipoprotein (HDL-C) and phospholipids were noticed. Genetic mutations in apolipoprotein E (ApoE), apolipoprotein B (ApoB), apolipoprotein A (ApoA), ATP binding cassette transporter 1 (ABCA1), ATP binding cassette transporter 7 (ABCA7), amyloid precursor protein (APP), cytochrome P450 family 46 subfamilies A member 1 (CYP46A1), presenilin 1 (PSEN1), presenilin 2 (PSEN2) are also associated with increased risk of Alzheimer's disease. This study found an association between plasma lipids and Alzheimer's, proving that plasma lipids can be used as biomarkers for early diagnosis of Alzheimer's disease. It may also help predict the prognosis and stage the disease severity. Further studies are needed to find out the exact mechanism behind these changes.
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Affiliation(s)
- Mehak Agarwal
- Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
| | - Safeera Khan
- Internal Medicine, California Institute of Behavioral Neurosciences & Psychology, Fairfield, USA
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16
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Zhou Z, Liang Y, Zhang X, Xu J, Lin J, Zhang R, Kang K, Liu C, Zhao C, Zhao M. Low-Density Lipoprotein Cholesterol and Alzheimer's Disease: A Systematic Review and Meta-Analysis. Front Aging Neurosci 2020; 12:5. [PMID: 32082137 PMCID: PMC7002548 DOI: 10.3389/fnagi.2020.00005] [Citation(s) in RCA: 21] [Impact Index Per Article: 5.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/07/2019] [Accepted: 01/09/2020] [Indexed: 12/15/2022] Open
Abstract
Objective: To assess the association between low-density lipoprotein cholesterol (LDL-c) and risk of Alzheimer's disease (AD). Methods: Embase, Pubmed, and Web of Science were searched until June 2019. Standard mean difference (SMD) with 95% confidence intervals (CI) was estimated using random-effects models. Results: Our meta-analysis of 26 studies revealed higher levels of LDL-c in AD than that of non-dementia controls (SMD = 0.35, 95% CI 0.12-0.58, p < 0.01). The meta-regression analysis on confounders showed that age (p < 0.01, Adj R-squared = 92.41%) and cardiovascular disease (p = 0.01, Adj R-squared = 85.21%), but not the body mass index, education, smoking, hypertension and diabetes mellitus, exerted an impact on the relationship between LDL-c and risk of ICH. Further subgroup analysis of age showed LDL-c levels in AD patients aged 60-70 were higher than that of non-dementia (60 ≤ age < 70: SMD = 0.80, 95% CI 0.23-1.37, p < 0.01); but no association between the SMD of AD in LDL-c and age over 70 was noted across the studies (70 ≤ age < 77: SMD = -0.02, 95% CI -0.39~0.34, p = 9.0; 77 ≤ age < 80: SMD = 0.15, 95% CI -0.17~0.47, p = 0.35; ≥80: SMD = 0.53, 95% CI -0.04~1.11, p = 0.07). The concentrations of LDL-c during the quintile interval of 3~4 were positively associated with AD (121 ≤ concentration < 137: SMD = 0.98, 95% CI 0.13~1.82, p = 0.02; ≥137: SMD = 0.62, 95% CI 0.18~1.06, p < 0.01); whereas there was no correlation between AD and LDL-c within the quintile interval of 1~2 (103.9 ≤ concentration < 112: SMD = 0.08, 95% CI -0.20~0.35, p = 0.59; 112 ≤ concentration < 121: SMD = -0.26, 95% CI -0.58~0.06, p = 0.11). Conclusions: Elevated concentration of LDL-c (>121 mg/dl) may be a potential risk factor for AD. This association is strong in patients aged 60-70 years, but vanishes with advancing age.
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Affiliation(s)
- Zhike Zhou
- Department of Geriatrics, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Yifan Liang
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Xiaoqian Zhang
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Junjie Xu
- Department of Laboratory Medicine, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Jueying Lin
- Department of Emergency, Zhongshan Hospital Xiamen University, Xiamen, China
| | - Rongwei Zhang
- Department of Geriatrics, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Kexin Kang
- Department of Geriatrics, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Chang Liu
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Chuansheng Zhao
- Department of Neurology, The First Affiliated Hospital, China Medical University, Shenyang, China
| | - Mei Zhao
- Department of Cardiology, The Shengjing Affiliated Hospital, China Medical University, Shenyang, China
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17
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Galloway S, Takechi R, Nesbit M, Pallebage-Gamarallage MM, Lam V, Mamo JCL. The differential effects of fatty acids on enterocytic abundance of amyloid-beta. Lipids Health Dis 2019; 18:209. [PMID: 31796080 PMCID: PMC6889564 DOI: 10.1186/s12944-019-1162-9] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/04/2019] [Accepted: 11/29/2019] [Indexed: 12/30/2022] Open
Abstract
Background Consumption of a Western-styled diet enriched in saturated fatty acids (SFA) relative to polyunsaturated fatty acids is positively associated with risk for Alzheimer’s disease. Whilst potential causal mechanism are unclear, there is increasing evidence that chronic ingestion of SFA enriched diets promote increase the plasma levels of lipoprotein-associated amyloid-β (Aβ). However, the effects of dietary mono- and poly-unsaturated fats (MUFA/PUFA) on nascent lipoprotein Aβ abundance have not been previously reported. Methods Wild-type C57BL/6 J mice were maintained on low-fat control chow (LF) or diets enriched in either SFA, MUFA, or PUFA for 9 months. Enterocytic abundance of Aβ was determined with quantitative immunofluorescent microscopy and plasma Aβ was measured by ELISA. Results The chronic ingestion of SFA-enriched diet increased the enterocytic abundance and plasma concentration of Aβ compared to LF control mice. The mice maintained on MUFA or PUFA diet showed comparable enterocytic and plasma Aβ levels to the LF control mice. Conclusions The data indicates that a diet enriched in SFA significantly increases the enterocytic Aβ production and secretion into the circulation, whilst MUFA and PUFA enriched diet do not exert such effects.
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Affiliation(s)
- Susan Galloway
- Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.,School of Public Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Ryusuke Takechi
- Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia. .,School of Public Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.
| | - Michael Nesbit
- Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.,School of Public Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Menuka M Pallebage-Gamarallage
- Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.,School of Public Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - Virginie Lam
- Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.,School of Public Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
| | - John C L Mamo
- Curtin Health Innovation Research Institute, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia.,School of Public Health, Faculty of Health Sciences, Curtin University, GPO Box U1987, Perth, WA, 6845, Australia
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18
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Nägga K, Gustavsson AM, Stomrud E, Lindqvist D, van Westen D, Blennow K, Zetterberg H, Melander O, Hansson O. Increased midlife triglycerides predict brain β-amyloid and tau pathology 20 years later. Neurology 2017; 90:e73-e81. [PMID: 29196581 PMCID: PMC5754649 DOI: 10.1212/wnl.0000000000004749] [Citation(s) in RCA: 65] [Impact Index Per Article: 9.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/04/2017] [Accepted: 09/27/2017] [Indexed: 12/28/2022] Open
Abstract
OBJECTIVE To evaluate the effect of midlife lipid levels on Alzheimer brain pathology 20 years later in cognitively normal elderly individuals. METHODS This is a longitudinal cohort study of 318 cognitively normal individuals with data on fasting lipid levels at midlife (mean age 54 years). Presence of β-amyloid (Aβ) and tau pathologies 20 years later (mean age 73 years) were detected by quantifying Alzheimer disease (AD) biomarkers in CSF. In a subset (n = 134), Aβ (18F-flutemetamol) PET was also performed. RESULTS CSF Aβ42 and Aβ PET revealed Aβ pathology in approximately 20% of the cognitively healthy population and CSF Aβ42/phosphorylated tau (p-tau) ratio indicated both Aβ and tau pathology in 16%. Higher levels of triglycerides in midlife were independently associated with abnormal CSF Aβ42 (odds ratio [OR] 1.34, 95% confidence interval [CI] 1.03-1.75, p = 0.029) and abnormal Aβ42/p-tau ratio (OR 1.46, 95% CI 1.10-1.93; p = 0.009) adjusting for age, sex, APOE ε4, education, and multiple vascular risk factors. Triglycerides were also associated with abnormal Aβ PET in multivariable regression models, but the association was attenuated in the fully adjusted model. Increased levels of medium and large low-density lipoprotein subfractions were significantly associated with abnormal Aβ PET and large high-density lipoprotein particles were associated with decreased risk of abnormal Aβ PET. CONCLUSIONS Increased levels of triglycerides at midlife predict brain Aβ and tau pathology 20 years later in cognitively healthy individuals. Certain lipoprotein subfractions may also be risk factors for Aβ pathology. These findings further support an involvement of lipids in the very early stages of AD development.
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Affiliation(s)
- Katarina Nägga
- From the Clinical Memory Research Unit (K.N., A.-M.G., E.S., O.H.) and Clinical Research Centre (O.M.), Department of Clinical Sciences Malmö, Lund University; Memory Clinic (K.N., A.-M.G., E.S., O.H.), Skåne University Hospital, Malmö; Psychiatry (D.L.) and Diagnostic Radiology (D.v.W.), Department of Clinical Sciences Lund, Lund University; Department of Psychiatry and Neurochemistry (K.B., H.Z.), Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (K.B., H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; and Department of Molecular Neuroscience (H.Z.), UCL Institute of Neurology, Queen Square, London, UK.
| | - Anna-Märta Gustavsson
- From the Clinical Memory Research Unit (K.N., A.-M.G., E.S., O.H.) and Clinical Research Centre (O.M.), Department of Clinical Sciences Malmö, Lund University; Memory Clinic (K.N., A.-M.G., E.S., O.H.), Skåne University Hospital, Malmö; Psychiatry (D.L.) and Diagnostic Radiology (D.v.W.), Department of Clinical Sciences Lund, Lund University; Department of Psychiatry and Neurochemistry (K.B., H.Z.), Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (K.B., H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; and Department of Molecular Neuroscience (H.Z.), UCL Institute of Neurology, Queen Square, London, UK
| | - Erik Stomrud
- From the Clinical Memory Research Unit (K.N., A.-M.G., E.S., O.H.) and Clinical Research Centre (O.M.), Department of Clinical Sciences Malmö, Lund University; Memory Clinic (K.N., A.-M.G., E.S., O.H.), Skåne University Hospital, Malmö; Psychiatry (D.L.) and Diagnostic Radiology (D.v.W.), Department of Clinical Sciences Lund, Lund University; Department of Psychiatry and Neurochemistry (K.B., H.Z.), Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (K.B., H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; and Department of Molecular Neuroscience (H.Z.), UCL Institute of Neurology, Queen Square, London, UK
| | - Daniel Lindqvist
- From the Clinical Memory Research Unit (K.N., A.-M.G., E.S., O.H.) and Clinical Research Centre (O.M.), Department of Clinical Sciences Malmö, Lund University; Memory Clinic (K.N., A.-M.G., E.S., O.H.), Skåne University Hospital, Malmö; Psychiatry (D.L.) and Diagnostic Radiology (D.v.W.), Department of Clinical Sciences Lund, Lund University; Department of Psychiatry and Neurochemistry (K.B., H.Z.), Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (K.B., H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; and Department of Molecular Neuroscience (H.Z.), UCL Institute of Neurology, Queen Square, London, UK
| | - Danielle van Westen
- From the Clinical Memory Research Unit (K.N., A.-M.G., E.S., O.H.) and Clinical Research Centre (O.M.), Department of Clinical Sciences Malmö, Lund University; Memory Clinic (K.N., A.-M.G., E.S., O.H.), Skåne University Hospital, Malmö; Psychiatry (D.L.) and Diagnostic Radiology (D.v.W.), Department of Clinical Sciences Lund, Lund University; Department of Psychiatry and Neurochemistry (K.B., H.Z.), Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (K.B., H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; and Department of Molecular Neuroscience (H.Z.), UCL Institute of Neurology, Queen Square, London, UK
| | - Kaj Blennow
- From the Clinical Memory Research Unit (K.N., A.-M.G., E.S., O.H.) and Clinical Research Centre (O.M.), Department of Clinical Sciences Malmö, Lund University; Memory Clinic (K.N., A.-M.G., E.S., O.H.), Skåne University Hospital, Malmö; Psychiatry (D.L.) and Diagnostic Radiology (D.v.W.), Department of Clinical Sciences Lund, Lund University; Department of Psychiatry and Neurochemistry (K.B., H.Z.), Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (K.B., H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; and Department of Molecular Neuroscience (H.Z.), UCL Institute of Neurology, Queen Square, London, UK
| | - Henrik Zetterberg
- From the Clinical Memory Research Unit (K.N., A.-M.G., E.S., O.H.) and Clinical Research Centre (O.M.), Department of Clinical Sciences Malmö, Lund University; Memory Clinic (K.N., A.-M.G., E.S., O.H.), Skåne University Hospital, Malmö; Psychiatry (D.L.) and Diagnostic Radiology (D.v.W.), Department of Clinical Sciences Lund, Lund University; Department of Psychiatry and Neurochemistry (K.B., H.Z.), Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (K.B., H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; and Department of Molecular Neuroscience (H.Z.), UCL Institute of Neurology, Queen Square, London, UK
| | - Olle Melander
- From the Clinical Memory Research Unit (K.N., A.-M.G., E.S., O.H.) and Clinical Research Centre (O.M.), Department of Clinical Sciences Malmö, Lund University; Memory Clinic (K.N., A.-M.G., E.S., O.H.), Skåne University Hospital, Malmö; Psychiatry (D.L.) and Diagnostic Radiology (D.v.W.), Department of Clinical Sciences Lund, Lund University; Department of Psychiatry and Neurochemistry (K.B., H.Z.), Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (K.B., H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; and Department of Molecular Neuroscience (H.Z.), UCL Institute of Neurology, Queen Square, London, UK
| | - Oskar Hansson
- From the Clinical Memory Research Unit (K.N., A.-M.G., E.S., O.H.) and Clinical Research Centre (O.M.), Department of Clinical Sciences Malmö, Lund University; Memory Clinic (K.N., A.-M.G., E.S., O.H.), Skåne University Hospital, Malmö; Psychiatry (D.L.) and Diagnostic Radiology (D.v.W.), Department of Clinical Sciences Lund, Lund University; Department of Psychiatry and Neurochemistry (K.B., H.Z.), Institute of Neuroscience and Physiology, The Sahlgrenska Academy at University of Gothenburg; Clinical Neurochemistry Laboratory (K.B., H.Z.), Sahlgrenska University Hospital, Mölndal, Sweden; and Department of Molecular Neuroscience (H.Z.), UCL Institute of Neurology, Queen Square, London, UK.
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Wallin C, Luo J, Jarvet J, Wärmländer SKTS, Gräslund A. The Amyloid-β Peptide in Amyloid Formation Processes: Interactions with Blood Proteins and Naturally Occurring Metal Ions. Isr J Chem 2016. [DOI: 10.1002/ijch.201600105] [Citation(s) in RCA: 16] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022]
Affiliation(s)
- Cecilia Wallin
- Department of Biochemistry and Biophysics; Arrhenius Laboratories; Stockholm University; 10691 Stockholm Sweden
| | - Jinghui Luo
- Department of Biochemistry and Biophysics; Arrhenius Laboratories; Stockholm University; 10691 Stockholm Sweden
- Chemical Research Laboratory; University of Oxford; 12 Mansfield Road Oxford Ox 1 3TA UK
| | - Jüri Jarvet
- Department of Biochemistry and Biophysics; Arrhenius Laboratories; Stockholm University; 10691 Stockholm Sweden
- The National Institute of Chemical Physics and Biophysics; Tallinn Estonia
| | | | - Astrid Gräslund
- Department of Biochemistry and Biophysics; Arrhenius Laboratories; Stockholm University; 10691 Stockholm Sweden
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20
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Choi HJ, Byun MS, Yi D, Choe YM, Sohn BK, Baek HW, Lee JH, Kim HJ, Han JY, Yoon EJ, Kim YK, Woo JI, Lee DY. Association Between Serum Triglycerides and Cerebral Amyloidosis in Cognitively Normal Elderly. Am J Geriatr Psychiatry 2016; 24:604-612. [PMID: 27311886 DOI: 10.1016/j.jagp.2016.03.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 08/24/2015] [Revised: 02/22/2016] [Accepted: 03/07/2016] [Indexed: 01/07/2023]
Abstract
OBJECTIVES Although many preclinical studies have suggested the possible linkage between dyslipidemia and cerebral amyloid deposition, the association between serum lipid measures and cerebral amyloid-beta (Aβ) deposition in human brain is still poorly known. We aimed to investigate the association in cognitively normal (CN) elderly individuals. DESIGN Cross-sectional study. SETTING University hospital dementia clinic. PARTICIPANTS 59 CN elderly. MEASUREMENTS The study measures included comprehensive clinical and neuropsychological assessment based on the CERAD protocol, magnetic resonance imaging and (11)C-labelled Pittsburgh Compound B positron emission tomography scans, and quantification for serum lipid biomarkers. RESULTS Multiple linear regression analyses showed that a higher serum triglycerides level was associated with heavier global cerebral Aβ deposition even after controlling age, sex, and apolipoprotein E ε4 genotype. Serum apolipoprotein B also showed significant positive association with global cerebral Aβ deposition, but the significance disappeared after controlling serum triglycerides level. No association was found between other lipid measures and global cerebral Aβ deposition. CONCLUSIONS The findings suggest that serum triglycerides are closely associated with cerebral amyloidosis, although population-based prospective studies are needed to provide further evidence of the causative effect of triglycerides on cerebral amyloidosis.
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Affiliation(s)
- Hyo Jung Choi
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Min Soo Byun
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Dahyun Yi
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Young Min Choe
- Department of Neuropsychiatry, Ulsan University Hospital, Ulsan, Republic of Korea
| | - Bo Kyung Sohn
- Department of Neuropsychiatry, Seoul National University Boramae Medical Center, Seoul, Republic of Korea
| | - Hye Won Baek
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Jun Ho Lee
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Hyun Jung Kim
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Ji Young Han
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Eun Jin Yoon
- Department of Nuclear Medicine, Seoul National University Boramae Medical Center, Seoul, Republic of Korea
| | - Yu Kyeong Kim
- Department of Nuclear Medicine, Seoul National University Boramae Medical Center, Seoul, Republic of Korea
| | - Jong Inn Woo
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea
| | - Dong Young Lee
- Department of Neuropsychiatry, Seoul National University Hospital, Seoul, Republic of Korea.
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21
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Hanson AJ, Bayer JL, Baker LD, Cholerton B, VanFossen B, Trittschuh E, Rissman RA, Donohue MC, Moghadam SH, Plymate SR, Craft S. Differential Effects of Meal Challenges on Cognition, Metabolism, and Biomarkers for Apolipoprotein E ɛ4 Carriers and Adults with Mild Cognitive Impairment. J Alzheimers Dis 2016; 48:205-18. [PMID: 26401941 DOI: 10.3233/jad-150273] [Citation(s) in RCA: 26] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
BACKGROUND High intake of saturated fat (SF) and glycemic index (GI) foods is a risk factor for sporadic Alzheimer's disease. Meal challenges may elucidate mechanisms that contribute to this risk, enabling development of targeted interventions. OBJECTIVE To assess cognitive and metabolic changes after a meal high in SF and GI calories (HIGH) versus a meal low in these macronutrients (LOW) in older adults with and without cognitive impairment, and with and without the apolipoprotein E4 risk factor. METHODS 46 adults with either cognitive impairment (CI) or normal cognition (NC) ingested a LOW (25% total fat, 7% SF, GI <55) and a HIGH meal (50% total fat, 25% SF, GI >70) in a blinded random fashion. Participants then underwent cognitive testing and blood sampling for metabolic and Alzheimer's disease biomarkers. Data were analyzed using repeated measures ANOVA and Spearman correlations. RESULTS E4-adults with NC demonstrated lower delayed memory scores after the HIGH compared to the LOW meal, whereas normal E4+ and CI E4- groups had higher scores after the HIGH meal (ANOVA p = 0.03). These findings were associated with meal-induced changes in glucose (p = 0.05), insulin (p = 0.004), triglycerides (p < 0.01), and plasma Aβ42 (p = 0.05). CONCLUSIONS These preliminary data suggest that cognitive performance of adults without CI may worsen following high SF and sugar meals, whereas adults with CI or those at risk for CI due to E4 status may benefit acutely from such meals. Furthermore, plasma Aβ was affected by meal type, suggesting a relationship between metabolic response and amyloid regulation.
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Affiliation(s)
- Angela J Hanson
- Department of Medicine, University of Washington Medical Center, Seattle, WA, USA
| | | | - Laura D Baker
- Sticht Center on Aging, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
| | - Brenna Cholerton
- Department of Medicine, University of Washington Medical Center, Seattle, WA, USA
| | | | | | - Robert A Rissman
- Alzheimer's Disease Cooperative Study, Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Michael C Donohue
- Alzheimer's Disease Cooperative Study, Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | - Setareh H Moghadam
- Alzheimer's Disease Cooperative Study, Department of Neurosciences, University of California San Diego, La Jolla, CA, USA
| | | | - Suzanne Craft
- Sticht Center on Aging, Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, NC, USA
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22
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Löffler T, Flunkert S, Temmel M, Hutter-Paier B. Decreased Plasma Aβ in Hyperlipidemic APPSL Transgenic Mice Is Associated with BBB Dysfunction. Front Neurosci 2016; 10:232. [PMID: 27313503 PMCID: PMC4887499 DOI: 10.3389/fnins.2016.00232] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2016] [Accepted: 05/10/2016] [Indexed: 11/13/2022] Open
Abstract
Besides the continued focus on Aβ and Tau in Alzheimer's disease (AD), it is increasingly evident that other pathologic characteristics, such as vascular alterations or inflammation, are associated with AD. Whether these changes are an initial cause for the onset of AD or occur as a result of the disease in late stages is still under debate. In the present study, the impact of the high-fat diet (HFD) induced vascular risk factor hyperlipidemia on Aβ levels and clearance as well as cerebral vasculature and blood-brain barrier (BBB) integrity was examined in mice. For this purpose, human APP transgenic (APPSL) and wildtype (WT) mice were fed a HFD for 12 weeks. Plasma and tissues were subsequently investigated for Aβ distribution and concentrations of several vascular markers. Decreased plasma Aβ together with increased levels of insoluble Aβ and amyloid plaques in the brains of HFD fed APPSL mice point toward impaired Aβ clearance due to HFD. Additionally, HFD induced manifold alterations in the cerebral vasculature and BBB integrity exclusively in human APP overexpressing mice but not in wildtype mice. Therefore, HFD appears to enhance Aβ dependent vascular/BBB dysfunction in combination with an increased proportion of cerebral to plasma Aβ in APPSL mice.
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Affiliation(s)
- Tina Löffler
- Neuropharmacology, QPS Austria Grambach, Austria
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23
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Ng KF, Anderson S, Mayo P, Aung HH, Walton JH, Rutledge JC. Characterizing blood-brain barrier perturbations after exposure to human triglyceride-rich lipoprotein lipolysis products using MRI in a rat model. Magn Reson Med 2015; 76:1246-51. [PMID: 26485349 PMCID: PMC4838551 DOI: 10.1002/mrm.25985] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/04/2015] [Revised: 08/11/2015] [Accepted: 08/21/2015] [Indexed: 12/11/2022]
Abstract
PURPOSE Previous studies indicated hyperlipidemia may be a risk factor for Alzheimer's disease, but the contributions of postprandial triglyceride-rich lipoprotein (TGRL) are not known. In this study, changes in blood-brain barrier diffusional transport following exposure to human TGRL lipolysis products were studied using MRI in a rat model. METHODS Male Sprague-Dawley rats (∼180-250 g) received an i.v. injection of lipoprotein lipase (LpL)-hydrolyzed TGRL (n = 8, plasma concentration ≈ 150 mg human TGRL/dL). Controls received i.v. injection of either saline (n = 6) or LpL only (n = 6). The (1) H longitudinal relaxation rate R1 = 1/T1 was measured over 18 min using a rapid-acquired refocus-echo (RARE) sequence after each of three injections of the contrast agent Gd-DTPA. Patlak plots were generated for each pixel yielding blood-to-brain transfer coefficients, Ki , chosen for best fit to impermeable, uni-directional influx or bi-directional flux models using the F-test. RESULTS Analysis from a 2-mm slice, 2-mm rostral to the bregma showed a 275% increase of mean Ki during the first 20 min after infusion of human TGRL lipolysis product that differed significantly compared with saline and LpL controls. This difference disappeared by 40 min mark. CONCLUSION These results suggest human TGRL lipolysis products can lead to a transient increase in rat BBB permeability. Magn Reson Med 76:1246-1251, 2016. © 2015 The Authors. Magnetic Resonance in Medicine published by Wiley Periodicals, Inc. on behalf of International Society for Magnetic Resonance in Medicine. This is an open access article under the terms of the Creative Commons Attribution NonCommercial License, which permits use, distribution and reproduction in any medium, provided the original work is properly cited and is not used for commercial purposes.
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Affiliation(s)
- Kit Fai Ng
- School of Medicine, Division of Cardiovascular Medicine, University of California, Davis, California, USA
| | - Steve Anderson
- School of Medicine, Department of Physiology and Membrane Biology, University of California, Davis, California, USA
| | - Patrice Mayo
- School of Medicine, Division of Cardiovascular Medicine, University of California, Davis, California, USA
| | - Hnin Hnin Aung
- School of Medicine, Division of Cardiovascular Medicine, University of California, Davis, California, USA
| | - Jeffrey H Walton
- NMR Facility and Biomedical Engineering Graduate Group, University of California, Davis, California, USA
| | - John C Rutledge
- School of Medicine, Division of Cardiovascular Medicine, University of California, Davis, California, USA.
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24
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Hanson AJ, Bayer-Carter JL, Green PS, Montine TJ, Wilkinson CW, Baker LD, Watson GS, Bonner LM, Callaghan M, Leverenz JB, Tsai E, Postupna N, Zhang J, Lampe J, Craft S. Effect of apolipoprotein E genotype and diet on apolipoprotein E lipidation and amyloid peptides: randomized clinical trial. JAMA Neurol 2013; 70:972-80. [PMID: 23779114 DOI: 10.1001/jamaneurol.2013.396] [Citation(s) in RCA: 71] [Impact Index Per Article: 6.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
IMPORTANCE Sporadic Alzheimer disease (AD) is caused in part by decreased clearance of the β-amyloid (Aβ) peptide breakdown products. Lipid-depleted (LD) apolipoproteins are less effective at binding and clearing Aβ, and LD Aβ peptides are more toxic to neurons. However, not much is known about the lipid states of these proteins in human cerebrospinal fluid. OBJECTIVE To characterize the lipidation states of Aβ peptides and apolipoprotein E in the cerebrospinal fluid in adults with respect to cognitive diagnosis and APOE ε4 allele carrier status and after a dietary intervention. DESIGN Randomized clinical trial. SETTING Veterans Affairs Medical Center clinical research unit. PARTICIPANTS Twenty older adults with normal cognition (mean [SD] age, 69 [7] years) and 27 with amnestic mild cognitive impairment (67 [6] years). INTERVENTIONS Randomization to a diet high in saturated fat content and with a high glycemic index (High diet; 45% of energy from fat [>25% saturated fat], 35%-40% from carbohydrates with a mean glycemic index >70, and 15%-20% from protein) or a diet low in saturated fat content and with a low glycemic index (Low diet; 25% of energy from fat [<7% saturated fat], 55%-60% from carbohydrates with a mean glycemic index <55, and 15%-20% from protein). MAIN OUTCOMES AND MEASURES Lipid-depleted Aβ42 and Aβ40 and apolipoprotein E in cerebrospinal fluid. RESULTS Baseline levels of LD Aβ were greater for adults with mild cognitive impairment compared with adults with normal cognition (LD Aβ42, P = .05; LD Aβ40, P = .01). These findings were magnified in adults with mild cognitive impairment and the ε4 allele, who had higher LD apolipoprotein E levels irrespective of cognitive diagnosis (P < .001). The Low diet tended to decrease LD Aβ levels, whereas the High diet increased these fractions (LD Aβ42, P = .01; LD Aβ40, P = .15). Changes in LD Aβ levels with the Low diet negatively correlated with changes in cerebrospinal fluid levels of insulin (LD Aβ42 and insulin, r = -0.68 [P = .01]; LD Aβ40 and insulin, r = -0.78 [P = .002]). CONCLUSIONS AND RELEVANCE The lipidation states of apolipoproteins and Aβ peptides in the brain differ depending on APOE genotype and cognitive diagnosis. Concentrations can be modulated by diet. These findings may provide insight into the mechanisms through which apolipoprotein E4 and unhealthy diets impart risk for developing AD.
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Affiliation(s)
- Angela J Hanson
- Geriatric Research, Veterans Affairs Puget Sound Health Care System, University of Washington School of Medicine, Seattle, Washington, USA
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25
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Cholerton B, Baker LD, Craft S. Insulin, cognition, and dementia. Eur J Pharmacol 2013; 719:170-179. [PMID: 24070815 DOI: 10.1016/j.ejphar.2013.08.008] [Citation(s) in RCA: 153] [Impact Index Per Article: 13.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/16/2013] [Revised: 08/21/2013] [Accepted: 08/26/2013] [Indexed: 01/21/2023]
Abstract
Cognitive disorders of aging represent a serious threat to the social and economic welfare of current society. It is now widely recognized that pathology related to such conditions, particularly Alzheimer's disease, likely begins years or decades prior to the onset of clinical dementia symptoms. This revelation has led researchers to consider candidate mechanisms precipitating the cascade of neuropathological events that eventually lead to clinical Alzheimer's disease. Insulin, a hormone with potent effects in the brain, has recently received a great deal of attention for its potential beneficial and protective role in cognitive function. Insulin resistance, which refers to the reduced sensitivity of target tissues to the favorable effects of insulin, is related to multiple chronic conditions known to impact cognition and increase dementia risk. With insulin resistance-associated conditions reaching epidemic proportions, the prevalence of Alzheimer's disease and other cognitive disorders will continue to rise exponentially. Fortunately, these chronic insulin-related conditions are amenable to pharmacological intervention. As a result, novel therapeutic strategies that focus on increasing insulin sensitivity in the brain may be an important target for protecting or treating cognitive decline. The following review will highlight our current understanding of the role of insulin in brain, potential mechanisms underlying the link between insulin resistance and dementia, and current experimental therapeutic strategies aimed at improving cognitive function via modifying the brain's insulin sensitivity.
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Affiliation(s)
- Brenna Cholerton
- Department of Psychiatry and Behavioral Science, University of Washington School of Medicine, Seattle, WA, USA; Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound Health Care System, Seattle, WA, USA
| | - Laura D Baker
- Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, Winston-Salem, NC 27157-1207, USA
| | - Suzanne Craft
- Department of Internal Medicine, Wake Forest University School of Medicine, Winston-Salem, North Carolina, Winston-Salem, NC 27157-1207, USA.
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Abstract
Sir Harold Himsworth's prescient observations 75 years ago have recently been expanded to include a clear relationship between insulin resistance and central nervous system function. Insulin is a master regulator of corporeal ageing in all known species, determining the rate and expression of ageing in multiple body systems. Thus, it is not surprising that insulin also plays an important role in brain ageing and cognitive decline that is associated with pathological brain ageing. Brain ageing is accompanied by reduced insulin effectiveness, either by an inadequate cellular response to insulin or by insulin deficiency attributable to reduced insulin transport across the blood-brain barrier. Age-associated brain insulin abnormalities may contribute to cognitive decline in ageing, as have been documented in older adults with Type 2 diabetes mellitus and hypertension. With more extreme pathology, brain insulin resistance may be associated with neurogenerative diseases such as Alzheimer's disease, and the condition which precedes Alzheimer's disease, known as amnestic mild cognitive impairment. In the following review, we discuss the mechanisms through which insulin resistance may induce or potentiate pathological brain ageing and thereby create a neurobiological environment that promotes neurodegeneration and associated cognitive decline. This topic is timely, given that insulin resistance-associated conditions such as diabetes and obesity have reached epidemic proportions. The prevalence of such chronic conditions, in combination with a rapidly ageing population, may result in a corresponding increase in the prevalence of Alzheimer's disease and other cognitive disorders. Fortunately, insulin resistance-associated conditions are amenable to both pharmacologic and lifestyle interventions that may reduce the deleterious impact of insulin resistance on the ageing brain.
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Affiliation(s)
- B Cholerton
- Geriatric Research, Education and Clinical Center, Veterans Affairs Puget Sound Health Care System, Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, WA 98108, USA
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27
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LaDu MJ, Munson GW, Jungbauer L, Getz GS, Reardon CA, Tai LM, Yu C. Preferential interactions between ApoE-containing lipoproteins and Aβ revealed by a detection method that combines size exclusion chromatography with non-reducing gel-shift. Biochim Biophys Acta Mol Cell Biol Lipids 2011; 1821:295-302. [PMID: 22138302 DOI: 10.1016/j.bbalip.2011.11.005] [Citation(s) in RCA: 26] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/07/2011] [Revised: 10/29/2011] [Accepted: 11/02/2011] [Indexed: 01/06/2023]
Abstract
The association between apolipoprotein E (apoE) and amyloid-β peptide (Aβ) may significantly impact the function of both proteins, thus affecting the etiology of Alzheimer's disease (AD). However, apoE/Aβ interactions remain fundamentally defined by the stringency of the detection method. Here we use size exclusion chromatography (SEC) as a non-stringent approach to the detection of apoE/Aβ interactions in solution, specifically apoE and both endogenous and exogenous Aβ from plasma, CSF and astrocyte conditioned media. By SEC analysis, Aβ association with plasma and CNS lipoproteins is apoE-dependent. While endogenous Aβ elutes to specific human plasma lipoproteins distinct from those containing apoE, it is the apoE-containing lipoproteins that absorb excess amounts of exogenous Aβ40. In human CSF, apoE, endogenous Aβ and phospholipid elute in an almost identical profile, as do apoE, exogenous Aβ and phospholipid from astrocyte conditioned media. Combining SEC fractionation with subsequent analysis for SDS-stable apoE/Aβ complex reveals that apoE-containing astrocyte lipoproteins exhibit the most robust interactions with Aβ. Thus, standardization of the methods for detecting apoE/Aβ complex is necessary to determine its functional significance in the neuropathology characteristic of AD. Importantly, a systematic understanding of the role of apoE-containing plasma and CNS lipoproteins in Aβ homeostasis could potentially contribute to identifying a plasma biomarker currently over-looked because it has multiple components.
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Affiliation(s)
- Mary Jo LaDu
- Department of Anatomy and Cell Biology, University of Illinois, Chicago, IL 60612, USA.
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28
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A diet enriched in docosahexanoic Acid exacerbates brain parenchymal extravasation of apo B lipoproteins induced by chronic ingestion of saturated fats. Int J Vasc Med 2011; 2012:647689. [PMID: 22121489 PMCID: PMC3216294 DOI: 10.1155/2012/647689] [Citation(s) in RCA: 9] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/27/2011] [Revised: 08/04/2011] [Accepted: 08/26/2011] [Indexed: 12/03/2022] Open
Abstract
Chronic ingestion of saturated fatty acids (SFAs) was previously shown to compromise blood-brain barrier integrity, leading to brain parenchymal extravasation of apolipoprotein B (apo B) lipoproteins enriched in amyloid beta. In contrast, diets enriched in mono- or polyunsaturated (PUFA) oils had no detrimental effect. Rather, n3 and n6 oils generally confer protection via suppression of inflammation. This study investigated in wild-type mice if a PUFA diet enriched in docosahexanoic acid (DHA) restored blood-brain barrier integrity and attenuated parenchymal apo B abundance induced by chronic ingestion of SFA. Cerebrovascular leakage of apo B was quantitated utilising immunofluorescent staining. The plasma concentration of brain-derived S100β was measured as a marker of cerebrovascular inflammation. In mice fed SFA for 3 months, provision thereafter of a DHA-enriched diet exacerbated parenchymal apo B retention, concomitant with a significant increase in plasma cholesterol. In contrast, provision of a low-fat diet following chronic SFA feeding had no effect on SFA-induced parenchymal apo B. The findings suggest that in a heightened state of cerebrovascular inflammation, the provision of unsaturated fatty acids may be detrimental, possibly as a consequence of a greater susceptibility for oxidation.
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29
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Probucol suppresses enterocytic accumulation of amyloid-β induced by saturated fat and cholesterol feeding. Lipids 2011; 47:27-34. [PMID: 21805327 DOI: 10.1007/s11745-011-3595-4] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/07/2011] [Accepted: 07/07/2011] [Indexed: 10/17/2022]
Abstract
Amyloid-β (Aβ) is secreted from lipogenic organs such as intestine and liver as an apolipoprotein of nascent triacylglycerol rich lipoproteins. Chronically elevated plasma Aβ may compromise cerebrovascular integrity and exacerbate amyloidosis--a hallmark feature of Alzheimer's disease (AD). Probucol is a hypocholesterolemic agent that reduces amyloid burden in transgenic amyloid mice, but the mechanisms for this effect are presently unclear. In this study, the effect of Probucol on intestinal lipoprotein-Aβ homeostasis was explored. Wild-type mice were fed a control low-fat diet and enterocytic Aβ was stimulated by high-fat (HF) diet enriched in 10% (w/w) saturated fat and 1% (w/w) cholesterol for the duration of 1 month. Mice treated with Probucol had the drug incorporated into the chow at 1% (w/w). Quantitative immunofluorescence was utilised to determine intestinal apolipoprotein B (apo B) and Aβ abundance. We found apo B in both the perinuclear region of the enterocytes and the lacteals in all groups. However, HF feeding and Probucol treatment increased secretion of apo B into the lacteals without any change in net villi abundance. On the other hand, HF-induced enterocytic perinuclear Aβ was significantly attenuated by Probucol. No significant changes in Aβ were observed within the lacteals. The findings of this study support the notion that Probucol suppresses dietary fat induced stimulation of Aβ biosynthesis and attenuate availability of apo B lipoprotein-Aβ for secretion.
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Lam V, Takechi R, Pallebage-Gamarallage MMS, Galloway S, Mamo JCL. Colocalisation of plasma derived apo B lipoproteins with cerebral proteoglycans in a transgenic-amyloid model of Alzheimer's disease. Neurosci Lett 2011; 492:160-4. [PMID: 21310214 DOI: 10.1016/j.neulet.2011.02.001] [Citation(s) in RCA: 13] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/17/2010] [Revised: 01/28/2011] [Accepted: 02/01/2011] [Indexed: 11/28/2022]
Abstract
Alzheimer's disease (AD) is characterized by cerebral proteinaceous deposits comprised of amyloid beta (Aβ). Evidence suggests that enhanced blood-to-brain delivery of Aβ occurs when plasma concentration is increased, exacerbating amyloidosis. In blood, significant Aβ is associated with apolipoprotein (apo) B lipoproteins. In this study, immunofluorescent microscopy was utilised to explore if there is an association between apo B lipoproteins and proteoglycan expression within Aβ-rich plaques in transgenic-amyloid mice. Focal accumulation of apo B was found with Aβ-plaque in APP/PS1 mice. There was enrichment in the proteoglycans, agrin, perlecan, biglycan and decorin within the core of dense Aβ-plaque. Perlecan, biglycan and decorin were positively associated with apo B lipoprotein abundance within amyloid plaque consistent with a cause-for-retention effect. These findings show that proteoglycans are an integral component of Aβ deposits in APP/PS1 mice. This study suggests that some proteoglycans contribute to Aβ retention, whilst other proteoglycans have different functions in the aetiology of AD.
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Affiliation(s)
- Virginie Lam
- Curtin Health Innovation Research Institute, and The Australian Technology Network Centre for Metabolic Fitness, Curtin University, Bentley Campus, Kent Street, Perth 6102, Australia
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Merlo S, Spampinato S, Canonico PL, Copani A, Sortino MA. Alzheimer's disease: brain expression of a metabolic disorder? Trends Endocrinol Metab 2010; 21:537-44. [PMID: 20541952 DOI: 10.1016/j.tem.2010.05.005] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 01/27/2010] [Revised: 05/11/2010] [Accepted: 05/12/2010] [Indexed: 01/11/2023]
Abstract
Alzheimer's disease (AD) is the most common form of dementia and is of rapidly increasing health, social and economic impact. Recent evidence suggests a strict link between metabolic disorders and AD. In the last decade much attention has focused specifically on the connection between dysfunction of lipid metabolism and AD. Here we discuss aspects of lipid regulation, including changes in cholesterol levels, function of apolipoproteins and leptin, and how these relate to AD pathogenesis. Despite the vast literature available, many aspects still need clarification. Nevertheless, the route is already delineated to directly connect aspects of lipid regulation to AD. This could represent a starting point to identify novel potential targets for a preventive and/or treatment strategy of the disease.
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Affiliation(s)
- Sara Merlo
- Department of Experimental and Clinical Pharmacology, University of Catania, Catania, Italy
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Post-prandial lipid metabolism, lipid-modulating agents and cerebrovascular integrity: implications for dementia risk. ATHEROSCLEROSIS SUPP 2010; 11:49-54. [PMID: 20430703 DOI: 10.1016/j.atherosclerosissup.2010.04.002] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/18/2010] [Revised: 04/08/2010] [Accepted: 04/08/2010] [Indexed: 10/19/2022]
Abstract
Amyloid-β (Aβ) is secreted as an apolipoprotein of nascent triglyceride-rich lipoproteins (TRL) derived from both liver and intestine, but is better recognized as the principal protein component of senile plaque in subjects with Alzheimer's disease. Recent studies suggest that exaggerated exposure to plasma Aβ can compromise cerebrovascular integrity, resulting thereafter in blood to brain delivery of plasma proteins including TRL-Aβ. Parenchymal deposits of Aβ show significant immunoreactivity to apolipoprotein B (apo B), consistent with the notion of lipoprotein-Aβ entrapment. In wild type mice chronically fed physiologically relevant diets, saturated fats (SFA) enhance chylomicron-Aβ concomitant with disturbances in blood-brain barrier integrity. Similarly, dietary cholesterol promotes cerebrovascular extravasation of apo B lipoprotein-Aβ. In this study, we investigated the effects of atorvastatin, pravastatin and probucol on dietary-fat induced disturbances in BBB function. Atorvastatin, a lipid soluble HMG-CoA reductase inhibitor prevented SFA induced parenchymal extravasation of apo B-Aβ at 28 days when incorporated into the diet at 20 mg/kg. In contrast, pravastatin a water soluble agent had no effect on BBB integrity at an equivalent dose. In cholesterol supplemented mice, probucol maintained BBB function and extravasation of apo B-Aβ was not evident. The findings suggest that some lipid-modulating agents may be effective in ameliorating the negative effects of saturated fats and cholesterol on cerebrovascular integrity.
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Dietary fats, cerebrovasculature integrity and Alzheimer's disease risk. Prog Lipid Res 2009; 49:159-70. [PMID: 19896503 DOI: 10.1016/j.plipres.2009.10.004] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/15/2009] [Revised: 10/30/2009] [Accepted: 10/30/2009] [Indexed: 01/08/2023]
Abstract
An emerging body of evidence is consistent with the hypothesis that dietary fats influence Alzheimer's disease (AD) risk, but less clear is the mechanisms by which this occurs. Alzheimer's is an inflammatory disorder, many consider in response to fibrillar formation and extracellular deposition of amyloid-beta (Abeta). Alternatively, amyloidosis could notionally be a secondary phenomenon to inflammation, because some studies suggest that cerebrovascular disturbances precede amyloid plaque formation. Hence, dietary fats may influence AD risk by either modulating Abeta metabolism, or via Abeta independent pathways. This review explores these two possibilities taking into consideration; (i) the substantial affinity of Abeta for lipids and its ordinary metabolism as an apolipoprotein; (ii) evidence that Abeta has potent vasoactive properties and (iii) studies which show that dietary fats modulate Abeta biogenesis and secretion. We discuss accumulating evidence that dietary fats significantly influence cerebrovascular integrity and as a consequence altered Abeta kinetics across the blood-brain barrier (BBB). Specifically, chronic ingestion of saturated fats or cholesterol appears to results in BBB dysfunction and exaggerated delivery from blood-to-brain of peripheral Abeta associated with lipoproteins of intestinal and hepatic origin. Interestingly, the pattern of saturated fat/cholesterol induced cerebrovascular disturbances in otherwise normal wild-type animal strains is analogous to established models of AD genetically modified to overproduce Abeta, consistent with a causal association. Saturated fats and cholesterol may exacerbate Abeta induced cerebrovascular disturbances by enhancing exposure of vessels of circulating Abeta. However, presently there is no evidence to support this contention. Rather, SFA and cholesterol appear to more broadly compromise BBB integrity with the consequence of plasma protein leakage into brain, including lipoprotein associated Abeta. The latter findings are consistent with the concept that AD is a dietary-fat induced phenotype of vascular dementia, reflecting the extraordinary entrapment of peripherally derived lipoproteins endogenously enriched in Abeta. Rather than being the initiating trigger for inflammation in AD, accumulation of extracellular lipoprotein-Abeta may be a secondary amplifier of dietary induced inflammation, or possibly, simply be consequential. Clearly, delineating the mechanisms by which dietary fats increase AD risk may be informative in developing new strategies for prevention and treatment of AD.
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Differential effects of dietary fatty acids on the cerebral distribution of plasma-derived apo B lipoproteins with amyloid-beta. Br J Nutr 2009; 103:652-62. [PMID: 19860996 DOI: 10.1017/s0007114509992194] [Citation(s) in RCA: 56] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/30/2022]
Abstract
Some dietary fats are a risk factor for Alzheimer's disease (AD) but the mechanisms for this association are presently unknown. In the present study we showed in wild-type mice that chronic ingestion of SFA results in blood-brain barrier (BBB) dysfunction and significant delivery into the brain of plasma proteins, including apo B lipoproteins that are endogenously enriched in amyloid-beta (Abeta). Conversely, the plasma concentration of S100B was used as a marker of brain-to-blood leakage and was found to be increased two-fold because of SFA feeding. Consistent with a deterioration in BBB integrity in SFA-fed mice was a diminished cerebrovascular expression of occludin, an endothelial tight junction protein. In contrast to SFA-fed mice, chronic ingestion of MUFA or PUFA had no detrimental effect on BBB integrity. Utilising highly sensitive three-dimensional immunomicroscopy, we also showed that the cerebral distribution and co-localisation of Abeta with apo B lipoproteins in SFA-fed mice are similar to those found in amyloid precursor protein/presenilin-1 (APP/PS1) amyloid transgenic mice, an established murine model of AD. Moreover, there was a strong positive association of plasma-derived apo B lipoproteins with cerebral Abeta deposits. Collectively, the findings of the present study provide a plausible explanation of how dietary fats may influence AD risk. Ingestion of SFA could enhance peripheral delivery to the brain of circulating lipoprotein-Abeta and exacerbate the amyloidogenic cascade.
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Galloway S, Takechi R, Pallebage-Gamarallage MMS, Dhaliwal SS, Mamo JCL. Amyloid-beta colocalizes with apolipoprotein B in absorptive cells of the small intestine. Lipids Health Dis 2009; 8:46. [PMID: 19845970 PMCID: PMC2771012 DOI: 10.1186/1476-511x-8-46] [Citation(s) in RCA: 32] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/10/2009] [Accepted: 10/22/2009] [Indexed: 11/17/2022] Open
Abstract
BACKGROUND Amyloid-beta is recognized as the major constituent of senile plaque found in subjects with Alzheimer's disease. However, there is increasing evidence that in a physiological context amyloid-beta may serve as regulating apolipoprotein, primarily of the triglyceride enriched lipoproteins. To consider this hypothesis further, this study utilized an in vivo immunological approach to explore in lipogenic tissue whether amyloid-beta colocalizes with nascent triglyceride-rich lipoproteins. RESULTS In murine absorptive epithelial cells of the small intestine, amyloid-beta had remarkable colocalization with chylomicrons (Manders overlap coefficient = 0.73 +/- 0.03 (SEM)), the latter identified as immunoreactive apolipoprotein B. A diet enriched in saturated fats doubled the abundance of both amyloid-beta and apo B and increased the overlap coefficient of the two proteins (0.87 +/- 0.02). However, there was no evidence that abundance of the two proteins was interdependent within the enterocytes (Pearson's Coefficient < 0.02 +/- 0.03), or in plasma (Pearson's Coefficient < 0.01). CONCLUSION The findings of this study are consistent with the possibility that amyloid-beta is secreted by enterocytes as an apolipoprotein component of chylomicrons. However, secretion of amyloid-beta appears to be independent of chylomicron biogenesis.
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Affiliation(s)
- Susan Galloway
- The Australian Technology Network Centre for Metabolic Fitness, School of Public Health, Curtin Health Innovation Research Institute, Curtin University of Technology, Perth, Western Australia, Australia
| | - Ryusuke Takechi
- The Australian Technology Network Centre for Metabolic Fitness, School of Public Health, Curtin Health Innovation Research Institute, Curtin University of Technology, Perth, Western Australia, Australia
| | - Menuka MS Pallebage-Gamarallage
- The Australian Technology Network Centre for Metabolic Fitness, School of Public Health, Curtin Health Innovation Research Institute, Curtin University of Technology, Perth, Western Australia, Australia
| | - Satvinder S Dhaliwal
- The Australian Technology Network Centre for Metabolic Fitness, School of Public Health, Curtin Health Innovation Research Institute, Curtin University of Technology, Perth, Western Australia, Australia
| | - John CL Mamo
- The Australian Technology Network Centre for Metabolic Fitness, School of Public Health, Curtin Health Innovation Research Institute, Curtin University of Technology, Perth, Western Australia, Australia
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Craft S. The role of metabolic disorders in Alzheimer disease and vascular dementia: two roads converged. ACTA ACUST UNITED AC 2009; 66:300-5. [PMID: 19273747 DOI: 10.1001/archneurol.2009.27] [Citation(s) in RCA: 372] [Impact Index Per Article: 24.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/22/2022]
Abstract
In recent years a rapidly increasing number of studies has focused on the relationship between dementia and metabolic disorders such as diabetes, obesity, hypertension, and dyslipidemia. Etiological heterogeneity and comorbidity pose challenges for determining relationships among metabolic disorders. The independent and interactive effects of brain vascular injury and classic pathological agents such as beta-amyloid have also proved difficult to distinguish in human patients, blurring the lines between Alzheimer disease and vascular dementia. This review highlights recent work aimed at identifying convergent mechanisms such as insulin resistance that may underlie comorbid metabolic disorders and thereby increase dementia risk. Identification of such convergent factors will not only provide important insight into the causes and interdependencies of late-life dementias but will also inspire novel strategies for treating and preventing these disorders.
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Affiliation(s)
- Suzanne Craft
- Geriatric Research, Education, and Clinical Center, Veterans Affairs Puget Sound, Department of Psychiatry and Behavioral Sciences, University of Washington School of Medicine, Seattle, 98108, USA.
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Takechi R, Galloway S, Pallebage-Gamarallage M, Wellington C, Johnsen R, Mamo JC. Three-dimensional colocalization analysis of plasma-derived apolipoprotein B with amyloid plaques in APP/PS1 transgenic mice. Histochem Cell Biol 2009; 131:661-6. [PMID: 19225804 DOI: 10.1007/s00418-009-0567-3] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 01/29/2009] [Indexed: 11/29/2022]
Abstract
Parenchymal accumulation of amyloid-beta (A beta) is a hallmark pathological feature of Alzheimer's disease. An emerging hypothesis is that blood-to-brain delivery of A beta may increase with compromised blood-brain barrier integrity. In plasma, substantial A beta is associated with triglyceride-rich lipoproteins (TRLs) secreted by the liver and intestine. Utilizing apolipoprotein B as an exclusive marker of hepatic and intestinal TRLs, here we show utilizing an highly sensitive 3-dimensional immuno-microscopy imaging technique, that in APP/PS1 amyloid transgenic mice, concomitant with substantially increased plasma A beta, there is a significant colocalization of apolipoprotein B with cerebral amyloid plaque. The findings are consistent with the possibility that circulating lipoprotein-A beta contributes to cerebral amyloidosis.
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Affiliation(s)
- Ryusuke Takechi
- Centre for Metabolic Fitness, School of Public Health, Curtin Health Innovative Research Institute, Curtin University of Technology, GPO Box U1987, Building 400, Bentley Campus, Perth, WA, 6845, Australia
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Takechi R, Galloway S, Pallebage-Gamarallage MMS, Mamo JCL. Chylomicron amyloid-beta in the aetiology of Alzheimer's disease. ATHEROSCLEROSIS SUPP 2008; 9:19-25. [PMID: 18640080 DOI: 10.1016/j.atherosclerosissup.2008.05.010] [Citation(s) in RCA: 30] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2008] [Revised: 03/12/2008] [Accepted: 05/13/2008] [Indexed: 01/08/2023]
Abstract
Alzheimer's disease is characterized by inflammatory proteinaceous deposits comprised principally of the protein amyloid-beta (Abeta). Presently, the origins of cerebral amyloid deposits are controversial, though pivotal for the prevention of Alzheimer's disease. Recent evidence suggests that in blood, Abeta may serve as a regulating apoprotein of the triglyceride-rich-lipoproteins and we have found that the synthesis of Abeta in enterocytes and thereafter secretion as part of the chylomicron cascade is regulated by dietary fats. It is our contention that chronically elevated plasma levels of Abeta in response to diets rich in saturated fats may lead to disturbances within the cerebrovasculature and exaggerated blood-to-brain delivery of circulating Abeta, thereby exacerbating amyloidosis. Consistent with this hypothesis we show that enterocytic Abeta is increased concomitant with apolipoprotein B48. Furthermore, cerebral extravasation of immunoglobulin G, a surrogate marker of plasma proteins is observed in a murine model of Alzheimer's disease maintained on a saturated-fat diet and there is diminished expression of occludin within the cerebrovasculature, an endothelial tight junction protein.
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Affiliation(s)
- R Takechi
- Faculty of Health Sciences, Curtin University of Technology, ATN Centre for Metabolic Health and Fitness, Building 400, Bentley Campus, Perth, Western Australia 6102, Australia
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