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Lei T, Yang Z, Li H, Qin M, Gao H. Interactions between nanoparticles and pathological changes of vascular in Alzheimer's disease. Adv Drug Deliv Rev 2024; 207:115219. [PMID: 38401847 DOI: 10.1016/j.addr.2024.115219] [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: 10/30/2023] [Revised: 02/16/2024] [Accepted: 02/20/2024] [Indexed: 02/26/2024]
Abstract
Emerging evidence suggests that vascular pathological changes play a pivotal role in the pathogenesis of Alzheimer's disease (AD). The dysfunction of the cerebral vasculature occurs in the early course of AD, characterized by alterations in vascular morphology, diminished cerebral blood flow (CBF), impairment of the neurovascular unit (NVU), vasculature inflammation, and cerebral amyloid angiopathy. Vascular dysfunction not only facilitates the influx of neurotoxic substances into the brain, triggering inflammation and immune responses but also hampers the efflux of toxic proteins such as Aβ from the brain, thereby contributing to neurodegenerative changes in AD. Furthermore, these vascular changes significantly impact drug delivery and distribution within the brain. Therefore, developing targeted delivery systems or therapeutic strategies based on vascular alterations may potentially represent a novel breakthrough in AD treatment. This review comprehensively examines various aspects of vascular alterations in AD and outlines the current interactions between nanoparticles and pathological changes of vascular.
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Affiliation(s)
- Ting Lei
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, West China School of Pharmacy, Mental Health Center and National Chengdu Center for Safety Evaluation of Drugs, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Zixiao Yang
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, West China School of Pharmacy, Mental Health Center and National Chengdu Center for Safety Evaluation of Drugs, West China Hospital, Sichuan University, Chengdu 610041, China
| | - Hanmei Li
- School of Food and Biological Engineering, Chengdu University, Chengdu 610106, China
| | - Meng Qin
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, West China School of Pharmacy, Mental Health Center and National Chengdu Center for Safety Evaluation of Drugs, West China Hospital, Sichuan University, Chengdu 610041, China.
| | - Huile Gao
- Key Laboratory of Drug-Targeting and Drug Delivery System of the Education Ministry and Sichuan Province, West China School of Pharmacy, Mental Health Center and National Chengdu Center for Safety Evaluation of Drugs, West China Hospital, Sichuan University, Chengdu 610041, China.
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de la Monte SM. Malignant Brain Aging: The Formidable Link Between Dysregulated Signaling Through Mechanistic Target of Rapamycin Pathways and Alzheimer's Disease (Type 3 Diabetes). J Alzheimers Dis 2023; 95:1301-1337. [PMID: 37718817 PMCID: PMC10896181 DOI: 10.3233/jad-230555] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/19/2023]
Abstract
Malignant brain aging corresponds to accelerated age-related declines in brain functions eventually derailing the self-sustaining forces that govern independent vitality. Malignant brain aging establishes the path toward dementing neurodegeneration, including Alzheimer's disease (AD). The full spectrum of AD includes progressive dysfunction of neurons, oligodendrocytes, astrocytes, microglia, and the microvascular systems, and is mechanistically driven by insulin and insulin-like growth factor (IGF) deficiencies and resistances with accompanying deficits in energy balance, increased cellular stress, inflammation, and impaired perfusion, mimicking the core features of diabetes mellitus. The underlying pathophysiological derangements result in mitochondrial dysfunction, abnormal protein aggregation, increased oxidative and endoplasmic reticulum stress, aberrant autophagy, and abnormal post-translational modification of proteins, all of which are signature features of both AD and dysregulated insulin/IGF-1-mechanistic target of rapamycin (mTOR) signaling. This article connects the dots from benign to malignant aging to neurodegeneration by reviewing the salient pathologies associated with initially adaptive and later dysfunctional mTOR signaling in the brain. Effective therapeutic and preventive measures must be two-pronged and designed to 1) address complex and shifting impairments in mTOR signaling through the re-purpose of effective anti-diabetes therapeutics that target the brain, and 2) minimize the impact of extrinsic mediators of benign to malignant aging transitions, e.g., inflammatory states, obesity, systemic insulin resistance diseases, and repeated bouts of general anesthesia, by minimizing exposures or implementing neuroprotective measures.
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Affiliation(s)
- Suzanne M. de la Monte
- Departments of Pathology and Laboratory Medicine, Medicine, Neurology and Neurosurgery, Rhode Island Hospital, Lifespan Academic Institutions, and the Warren Alpert Medical School of Brown University, Providence, RI, USA
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Ca 2+ homeostasis in brain microvascular endothelial cells. INTERNATIONAL REVIEW OF CELL AND MOLECULAR BIOLOGY 2021; 362:55-110. [PMID: 34253298 DOI: 10.1016/bs.ircmb.2021.01.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
Blood brain barrier (BBB) is formed by the brain microvascular endothelial cells (BMVECs) lining the wall of brain capillaries. Its integrity is regulated by multiple mechanisms, including up/downregulation of tight junction proteins or adhesion molecules, altered Ca2+ homeostasis, remodeling of cytoskeleton, that are confined at the level of BMVECs. Beside the contribution of BMVECs to BBB permeability changes, other cells, such as pericytes, astrocytes, microglia, leukocytes or neurons, etc. are also exerting direct or indirect modulatory effects on BBB. Alterations in BBB integrity play a key role in multiple brain pathologies, including neurological (e.g. epilepsy) and neurodegenerative disorders (e.g. Alzheimer's disease, Parkinson's disease, amyotrophic lateral sclerosis etc.). In this review, the principal Ca2+ signaling pathways in brain microvascular endothelial cells are discussed and their contribution to BBB integrity is emphasized. Improving the knowledge of Ca2+ homeostasis alterations in BMVECa is fundamental to identify new possible drug targets that diminish/prevent BBB permeabilization in neurological and neurodegenerative disorders.
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Nyúl-Tóth Á, Tarantini S, Kiss T, Toth P, Galvan V, Tarantini A, Yabluchanskiy A, Csiszar A, Ungvari Z. Increases in hypertension-induced cerebral microhemorrhages exacerbate gait dysfunction in a mouse model of Alzheimer's disease. GeroScience 2020; 42:1685-1698. [PMID: 32844283 PMCID: PMC7732885 DOI: 10.1007/s11357-020-00256-3] [Citation(s) in RCA: 30] [Impact Index Per Article: 7.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/19/2020] [Accepted: 08/17/2020] [Indexed: 12/17/2022] Open
Abstract
Clinical studies show that cerebral amyloid angiopathy (CAA) associated with Alzheimer's disease (AD) and arterial hypertension are independent risk factors for cerebral microhemorrhages (CMHs). To test the hypothesis that amyloid pathology and hypertension interact to promote the development of CMHs, we induced hypertension in the Tg2576 mouse model of AD and respective controls by treatment with angiotensin II (Ang II) and the NO synthesis inhibitor L-NAME. The number, size, localization, and neurological consequences (gait alterations) of CMHs were compared. We found that compared to control mice, in TG2576 mice, the same level of hypertension led to significantly increased CMH burden and exacerbation of CMH-related gait alterations. In hypertensive TG2576 mice, CMHs were predominantly located in the cerebral cortex at the cortical-subcortical boundary, mimicking the clinical picture seen in patients with CAA. Collectively, amyloid pathologies exacerbate the effects of hypertension, promoting the genesis of CMHs, which likely contribute to their deleterious effects on cognitive function. Therapeutic strategies for prevention of CMHs that reduce blood pressure and preserve microvascular integrity are expected to exert neuroprotective effects in high-risk elderly AD patients.
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Affiliation(s)
- Ádám Nyúl-Tóth
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Institute of Biophysics, Biological Research Centre, Szeged, Hungary
| | - Stefano Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Tamas Kiss
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Peter Toth
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
- International Training Program in Geroscience, Doctoral School of Clinical Medicine, Department of Neurosurgery and Szentagothai Research Center, Medical School, University of Pecs, Pecs, Hungary
| | - Veronica Galvan
- Department of Cellular and Integrative Physiology, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- Barshop Institute for Longevity and Aging Studies, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
- South Texas Veterans Health Care System, San Antonio, TX, USA
- Glenn Biggs Institute for Alzheimer's & Neurodegenerative Diseases, University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Amber Tarantini
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary
| | - Andriy Yabluchanskiy
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Anna Csiszar
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- Vascular Cognitive Impairment and Neurodegeneration Program, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, Department of Biochemistry and Molecular Biology, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- International Training Program in Geroscience, Doctoral School of Basic and Translational Medicine/Department of Public Health, Semmelweis University, Budapest, Hungary.
- International Training Program in Geroscience, Theoretical Medicine Doctoral School/Departments of Medical Physics and Informatics & Cell Biology and Molecular Medicine, University of Szeged, Szeged, Hungary.
- Department of Biochemistry and Molecular Biology, Reynolds Oklahoma Center on Aging/Center for Geroscience and Healthy Brain Aging, University of Oklahoma Health Sciences Center, 975 NE 10th Street, BRC 1311, Oklahoma City, OK, 73104, USA.
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Kuter KZ, Cenci MA, Carta AR. The role of glia in Parkinson's disease: Emerging concepts and therapeutic applications. PROGRESS IN BRAIN RESEARCH 2020; 252:131-168. [PMID: 32247363 DOI: 10.1016/bs.pbr.2020.02.004] [Citation(s) in RCA: 12] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/11/2022]
Abstract
Originally believed to primarily affect neurons, Parkinson's disease (PD) has recently been recognized to also affect the functions and integrity of microglia and astroglia, two cell categories of fundamental importance to brain tissue homeostasis, defense, and repair. Both a loss of glial supportive-defensive functions and a toxic gain of glial functions are implicated in the neurodegenerative process. Moreover, the chronic treatment with L-DOPA may cause maladaptive glial plasticity favoring a development of therapy complications. This chapter focuses on the pathophysiology of PD from a glial point of view, presenting this rapidly growing field from the first discoveries made to the most recent developments. We report and compare histopathological and molecular findings from experimental models of PD and human studies. We moreover discuss the important role played by astrocytes in compensatory adaptations taking place during presymptomatic disease stages. We finally describe examples of potential therapeutic applications stemming from an increased understanding of the important roles of glia in PD.
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Affiliation(s)
- Katarzyna Z Kuter
- Department of Neuropsychopharmacology, Maj Institute of Pharmacology, Polish Academy of Sciences, Krakow, Poland.
| | - M Angela Cenci
- Basal Ganglia Pathophysiology Unit, Department of Experimental Medical Science, Lund University, Lund, Sweden
| | - Anna R Carta
- Department of Biomedical Sciences, University of Cagliari, Cittadella Universitaria di Monserrato, Cagliari, Italy.
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de la Monte SM. The Full Spectrum of Alzheimer's Disease Is Rooted in Metabolic Derangements That Drive Type 3 Diabetes. ADVANCES IN EXPERIMENTAL MEDICINE AND BIOLOGY 2019; 1128:45-83. [PMID: 31062325 PMCID: PMC9996398 DOI: 10.1007/978-981-13-3540-2_4] [Citation(s) in RCA: 38] [Impact Index Per Article: 7.6] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
Abstract
The standard practice in neuropathology is to diagnose Alzheimer's disease (AD) based on the distribution and abundance of neurofibrillary tangles and Aβ deposits. However, other significant abnormalities including neuroinflammation, gliosis, white matter degeneration, non-Aβ microvascular disease, and insulin-related metabolic dysfunction require further study to understand how they could be targeted to more effectively remediate AD. This review addresses non-Aβ and non-pTau AD-associated pathologies, highlighting their major features, roles in neurodegeneration, and etiopathic links to deficits in brain insulin and insulin-like growth factor signaling and cognitive impairment. The discussion delineates why AD with its most characteristic clinical and pathological phenotypic profiles should be regarded as a brain form of diabetes, i.e., type 3 diabetes, and entertains the hypothesis that type 3 diabetes is just one of the categories of insulin resistance diseases that can occur independently or overlap with one or more of the others, including type 2 diabetes, metabolic syndrome, and nonalcoholic fatty liver disease.
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Affiliation(s)
- Suzanne M de la Monte
- Departments of Neurology, Neuropathology, and Neurosurgery, Rhode Island Hospital, and the Alpert Medical School of Brown University, Providence, RI, USA.
- Department of Pathology and Laboratory Medicine, Providence VA Medical Center, Providence, RI, USA.
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7
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Zhang N, Chen J, Ferraro GB, Wu L, Datta M, Jain RK, Plotkin SR, Stemmer-Rachamimov A, Xu L. Anti-VEGF treatment improves neurological function in tumors of the nervous system. Exp Neurol 2017; 299:326-333. [PMID: 28911884 DOI: 10.1016/j.expneurol.2017.09.008] [Citation(s) in RCA: 12] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/05/2017] [Revised: 07/05/2017] [Accepted: 09/10/2017] [Indexed: 01/17/2023]
Abstract
Research of various diseases of the nervous system has shown that VEGF has direct neuroprotective effects in the central and peripheral nervous systems, and indirect effects on improving neuronal vessel perfusion which leads to nerve protection. In the tumors of the nervous system, VEGF plays a critical role in tumor angiogenesis and tumor progression. The effect of anti-VEGF treatment on nerve protection and function has been recently reported - by normalizing the tumor vasculature, anti-VEGF treatment is able to relieve nerve edema and deliver oxygen more efficiently into the nerve, thus reducing nerve damage and improving nerve function. This review aims to summarize the divergent roles of VEGF in diseases of the nervous system and the recent findings of anti-VEGF therapy in nerve damage/regeneration and function in tumors, specifically, in Neurofibromatosis type 2 associated schwannomas.
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Affiliation(s)
- Na Zhang
- Edwin Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Jie Chen
- Edwin Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Gino B Ferraro
- Edwin Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Limeng Wu
- Edwin Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Meenal Datta
- Edwin Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA; Department of Chemical and Biological Engineering, Tufts University, Medford, MA 02155, USA
| | - Rakesh K Jain
- Edwin Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA
| | - Scott R Plotkin
- Department of Neurology and Cancer Center, Massachusetts General Hospital, USA
| | - Anat Stemmer-Rachamimov
- Department of Pathology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
| | - Lei Xu
- Edwin Steele Laboratories, Department of Radiation Oncology, Massachusetts General Hospital, Harvard Medical School, Boston, MA 02114, USA.
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Csiszar A, Tarantini S, Fülöp GA, Kiss T, Valcarcel-Ares MN, Galvan V, Ungvari Z, Yabluchanskiy A. Hypertension impairs neurovascular coupling and promotes microvascular injury: role in exacerbation of Alzheimer's disease. GeroScience 2017; 39:359-372. [PMID: 28853030 PMCID: PMC5636770 DOI: 10.1007/s11357-017-9991-9] [Citation(s) in RCA: 72] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/18/2017] [Accepted: 07/26/2017] [Indexed: 12/13/2022] Open
Abstract
Hypertension in the elderly substantially increases both the risk of vascular cognitive impairment (VCI) and Alzheimer's disease (AD); however, the underlying mechanisms are not completely understood. This review discusses the effects of hypertension on structural and functional integrity of cerebral microcirculation, including hypertension-induced alterations in neurovascular coupling responses, cellular and molecular mechanisms involved in microvascular damage (capillary rarefaction, blood-brain barrier disruption), and the genesis of cerebral microhemorrhages and their potential role in exacerbation of cognitive decline associated with AD. Understanding and targeting the hypertension-induced cerebromicrovascular alterations that are involved in the onset and progression of AD and contribute to cognitive impairment are expected to have a major role in preserving brain health in high-risk older individuals.
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Affiliation(s)
- Anna Csiszar
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Stefano Tarantini
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Gábor A Fülöp
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Division of Clinical Physiology, Faculty of Medicine, University of Debrecen, Debrecen, Hungary
| | - Tamas Kiss
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - M Noa Valcarcel-Ares
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Veronica Galvan
- Department of Cellular and Integrative Physiology, Barshop Institute for Longevity and Aging Studies University of Texas Health Science Center at San Antonio, San Antonio, TX, USA
| | - Zoltan Ungvari
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA
| | - Andriy Yabluchanskiy
- Reynolds Oklahoma Center on Aging, Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
- Translational Geroscience Laboratory, Donald W. Reynolds Department of Geriatric Medicine, University of Oklahoma Health Sciences Center, Oklahoma City, OK, USA.
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Toth P, Tarantini S, Csiszar A, Ungvari Z. Functional vascular contributions to cognitive impairment and dementia: mechanisms and consequences of cerebral autoregulatory dysfunction, endothelial impairment, and neurovascular uncoupling in aging. Am J Physiol Heart Circ Physiol 2017; 312:H1-H20. [PMID: 27793855 PMCID: PMC5283909 DOI: 10.1152/ajpheart.00581.2016] [Citation(s) in RCA: 315] [Impact Index Per Article: 45.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/07/2016] [Revised: 10/10/2016] [Accepted: 10/26/2016] [Indexed: 12/16/2022]
Abstract
Increasing evidence from epidemiological, clinical and experimental studies indicate that age-related cerebromicrovascular dysfunction and microcirculatory damage play critical roles in the pathogenesis of many types of dementia in the elderly, including Alzheimer's disease. Understanding and targeting the age-related pathophysiological mechanisms that underlie vascular contributions to cognitive impairment and dementia (VCID) are expected to have a major role in preserving brain health in older individuals. Maintenance of cerebral perfusion, protecting the microcirculation from high pressure-induced damage and moment-to-moment adjustment of regional oxygen and nutrient supply to changes in demand are prerequisites for the prevention of cerebral ischemia and neuronal dysfunction. This overview discusses age-related alterations in three main regulatory paradigms involved in the regulation of cerebral blood flow (CBF): cerebral autoregulation/myogenic constriction, endothelium-dependent vasomotor function, and neurovascular coupling responses responsible for functional hyperemia. The pathophysiological consequences of cerebral microvascular dysregulation in aging are explored, including blood-brain barrier disruption, neuroinflammation, exacerbation of neurodegeneration, development of cerebral microhemorrhages, microvascular rarefaction, and ischemic neuronal dysfunction and damage. Due to the widespread attention that VCID has captured in recent years, the evidence for the causal role of cerebral microvascular dysregulation in cognitive decline is critically examined.
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Affiliation(s)
- Peter Toth
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Neurosurgery and Szentagothai Research Center, University of Pecs, Pecs, Hungary; and
| | - Stefano Tarantini
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
| | - Anna Csiszar
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
| | - Zoltan Ungvari
- Department of Geriatric Medicine, Reynolds Oklahoma Center on Aging, University of Oklahoma Health Sciences Center, Oklahoma City, Oklahoma;
- Department of Medical Physics and Informatics, University of Szeged, Szeged, Hungary
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Pallebage-Gamarallage M, Takechi R, Lam V, Elahy M, Mamo J. Pharmacological modulation of dietary lipid-induced cerebral capillary dysfunction: Considerations for reducing risk for Alzheimer's disease. Crit Rev Clin Lab Sci 2015; 53:166-83. [PMID: 26678521 DOI: 10.3109/10408363.2015.1115820] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/24/2022]
Abstract
An increasing body of evidence suggests that cerebrovascular dysfunction and microvessel disease precede the evolution of hallmark pathological features that characterise Alzheimer's disease (AD), consistent with a causal association for onset or progression. Recent studies, principally in genetically unmanipulated animal models, suggest that chronic ingestion of diets enriched in saturated fats and cholesterol may compromise blood-brain barrier (BBB) integrity resulting in inappropriate blood-to-brain extravasation of plasma proteins, including lipid macromolecules that may be enriched in amyloid-β (Aβ). Brain parenchymal retention of blood proteins and lipoprotein bound Aβ is associated with heightened neurovascular inflammation, altered redox homeostasis and nitric oxide (NO) metabolism. Therefore, it is a reasonable proposition that lipid-lowering agents may positively modulate BBB integrity and by extension attenuate risk or progression of AD. In addition to their robust lipid lowering properties, reported beneficial effects of lipid-lowering agents were attributed to their pleiotropic properties via modulation of inflammation, oxidative stress, NO and Aβ metabolism. The review is a contemporary consideration of a complex body of literature intended to synthesise focussed consideration of mechanisms central to regulation of BBB function and integrity. Emphasis is given to dietary fat driven significant epidemiological evidence consistent with heightened risk amongst populations consuming greater amounts of saturated fats and cholesterol. In addition, potential neurovascular benefits associated with the use of hypolipidemic statins, probucol and fenofibrate are also presented in the context of lipid-lowering and pleiotropic properties.
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Affiliation(s)
- Menuka Pallebage-Gamarallage
- a Faculty of Health Sciences , School of Public Health Curtin University , Perth , WA , Australia and.,b Curtin Health Innovation Research Institute of Aging and Chronic Disease, Curtin University , Perth , WA , Australia
| | - Ryusuke Takechi
- a Faculty of Health Sciences , School of Public Health Curtin University , Perth , WA , Australia and.,b Curtin Health Innovation Research Institute of Aging and Chronic Disease, Curtin University , Perth , WA , Australia
| | - Virginie Lam
- a Faculty of Health Sciences , School of Public Health Curtin University , Perth , WA , Australia and.,b Curtin Health Innovation Research Institute of Aging and Chronic Disease, Curtin University , Perth , WA , Australia
| | - Mina Elahy
- a Faculty of Health Sciences , School of Public Health Curtin University , Perth , WA , Australia and.,b Curtin Health Innovation Research Institute of Aging and Chronic Disease, Curtin University , Perth , WA , Australia
| | - John Mamo
- a Faculty of Health Sciences , School of Public Health Curtin University , Perth , WA , Australia and.,b Curtin Health Innovation Research Institute of Aging and Chronic Disease, Curtin University , Perth , WA , Australia
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Mosley RL, Hutter-Saunders JA, Stone DK, Gendelman HE. Inflammation and adaptive immunity in Parkinson's disease. Cold Spring Harb Perspect Med 2013; 2:a009381. [PMID: 22315722 DOI: 10.1101/cshperspect.a009381] [Citation(s) in RCA: 185] [Impact Index Per Article: 16.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/19/2022]
Abstract
The immune system is designed to protect the host from infection and injury. However, when an adaptive immune response continues unchecked in the brain, the proinflammatory innate microglial response leads to the accumulation of neurotoxins and eventual neurodegeneration. What drives such responses are misfolded and nitrated proteins. Indeed, the antigen in Parkinson's disease (PD) is an aberrant self-protein, although the adaptive immune responses are remarkably similar in a range of diseases. Ingress of lymphocytes and chronic activation of glial cells directly affect neurodegeneration. With this understanding, new therapies aimed at modulating the immune system's response during PD could lead to decreased neuronal loss and improved clinical outcomes for disease.
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Affiliation(s)
- R Lee Mosley
- Movement Disorders Program, Department of Pharmacology and Experimental Neuroscience, Center for Neurodegenerative Disorders, University of Nebraska Medical Center, Omaha, Nebraska 68198, USA
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Spumiform capillary basement membrane swelling: a new type of microvascular degeneration in senescent hamster. Neurobiol Aging 2013; 34:1277-86. [DOI: 10.1016/j.neurobiolaging.2012.09.009] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/05/2012] [Revised: 06/28/2012] [Accepted: 09/07/2012] [Indexed: 01/10/2023]
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Gerrits P, Kortekaas R, de Weerd H, Luiten P, van der Want J, Veening J. Spumiform basement membrane aberrations in the microvasculature of the midbrain periaqueductal gray region in hamster: Rostro-caudal pathogenesis? Neuroscience 2013; 228:128-38. [DOI: 10.1016/j.neuroscience.2012.10.021] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.1] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/05/2012] [Revised: 10/04/2012] [Accepted: 10/06/2012] [Indexed: 11/28/2022]
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Hutter-Saunders JAL, Mosley RL, Gendelman HE. Pathways towards an effective immunotherapy for Parkinson's disease. Expert Rev Neurother 2012; 11:1703-15. [PMID: 22091596 DOI: 10.1586/ern.11.163] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
Immunizations that target specific types of immune responses are used commonly to prevent microbial infections. However, a range of immune responses may prove necessary to combat the ravages of neurodegenerative diseases. The goal is to eliminate the 'root' cause of neurodegenerative disorders, misfolded aggregated proteins, while harnessing adaptive immune responses to promote neural repair. However, immunization strategies used to elicit humoral immune responses against aberrant brain proteins have yielded mixed success. While specific proteins can be cleared, the failures in halting disease progression revolve, in measure, around adaptive immune responses that promote autoreactive T cells and, as such, induce a meningoencephalitis, accelerating neurodegeneration. Thus, alternative approaches for protein clearance and neural repair are desired. To this end, our laboratories have sought to transform autoreactive adaptive immune responses into regulatory neuroprotective cells in Parkinson's disease. In this context, induction of immune responses against modified brain proteins serves to break immunological tolerance, while eliciting adaptive immunity to facilitate neuronal repair. How to harness the immune response in the setting of Parkinson's disease requires a thorough understanding of the role of immunity in human disease and the ways to modify such immune responses to elicit therapeutic gain. These are discussed in this review.
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Affiliation(s)
- Jessica A L Hutter-Saunders
- Department of Pharmacology and Experimental Neuroscience, University of Nebraska Medical Center, Omaha, NE 68198, USA
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Baloyannis SJ, Baloyannis IS. The vascular factor in Alzheimer's disease: a study in Golgi technique and electron microscopy. J Neurol Sci 2012; 322:117-21. [PMID: 22857991 DOI: 10.1016/j.jns.2012.07.010] [Citation(s) in RCA: 96] [Impact Index Per Article: 8.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/31/2012] [Revised: 06/19/2012] [Accepted: 07/05/2012] [Indexed: 12/31/2022]
Abstract
Although the etiopathological background of Alzheimer's disease (AD) is mostly associated with the deposition of Αβ-peptide, the hyperphosphorylation of τ protein, the synaptic pathology and the mitochondrial alterations, the vascular factor may play substantial role in plotting the multifactorial pattern of the disease. We attempted to study the blood capillaries in the hippocampus, the acoustic, the visual and the parietal cortex in twelve early cases of Alzheimer's disease. Samples were processed for Golgi silver impregnation technique and electron microscopy. The morphological findings were compared with normal controls. The study of the brain capillaries in cases of AD, revealed numerous fusiform dilatations, tortuosities, abnormal branching and fusion, though the morphometric estimation revealed a decrease of the number of capillaries per mm(3) in comparison with normal control brains. The ultrastructural study revealed mitochondrial abnormalities in the endothelial cells of a substantial number of capillaries and marked degeneration of the pericytes. Perivascular microglial proliferation was also prominent in the hippocampus and the parietal lobe. Our findings both in Golgi staining and electron microscopy plead in favor of the essential role that the microvascular alterations may play in the broad pathogenetic spectrum of AD.
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Sharma HS, Castellani RJ, Smith MA, Sharma A. The blood-brain barrier in Alzheimer's disease: novel therapeutic targets and nanodrug delivery. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2012; 102:47-90. [PMID: 22748826 DOI: 10.1016/b978-0-12-386986-9.00003-x] [Citation(s) in RCA: 71] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
Abstract
Treatment strategies for Alzheimer's disease (AD) are still elusive. Thus, new strategies are needed to understand the pathogenesis of AD in order to provide suitable therapeutic measures. Available evidences suggest that in AD, passage across the blood-brain barrier (BBB) and transport exchanges for amyloid-β-peptide (ABP) between blood and the central nervous system (CNS) compartments play an important regulatory role for the deposition of brain ABP. New evidences suggest that BBB is altered in AD. Studies favoring transport theory clearly show that ABP putative receptors at the BBB control the level of soluble isoform of ABP in brain. This is achieved by regulating influx of circulating ABP into brain via specific receptor for advanced glycation end products (RAGE) and gp330/megalin-mediated transcytosis. On the other hand, the efflux of brain-derived ABP into the circulation across the vascular system via BBB is accomplished by low-density receptor-related protein-1 (LRP1). Furthermore, an increased BBB permeability in AD is also likely since structural damage of endothelial cells is quite frequent in AD brain. Thus, enhanced drug delivery in AD is needed to induce neuroprotection and therapeutic success. For this purpose, nanodrug delivery could be one of the available options that require active consideration for novel therapeutic strategies to treat AD cases. This review is focused on these aspects and provides new data showing that BBB plays an important role in AD-induced neurodegeneration and neurorepair.
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Affiliation(s)
- Hari Shanker Sharma
- Cerebrovascular Research Laboratory, Department of Surgical Sciences, Anesthesiology & Intensive Care Medicine, University Hospital, Uppsala University, Uppsala, Sweden
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The blood-brain barrier and microvascular water exchange in Alzheimer's disease. Cardiovasc Psychiatry Neurol 2011; 2011:615829. [PMID: 21687589 PMCID: PMC3114411 DOI: 10.1155/2011/615829] [Citation(s) in RCA: 20] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 09/02/2010] [Accepted: 02/12/2011] [Indexed: 01/08/2023] Open
Abstract
Alzheimer's disease (AD) is the most common form of dementia in the elderly. Although traditionally considered a disease of neurofibrillary tangles and amyloid plaques, structural and functional changes in the microvessels may contribute directly to the pathogenesis of the disease. Since vascular dysfunction often precedes cognitive impairment, understanding the role of the blood-brain barrier (BBB) in AD may be key to rational treatment of the disease. We propose that water regulation, a critical function of the BBB, is disturbed in AD and results in abnormal permeability and rates of water exchange across the vessel walls. In this paper, we describe some of the pathological events that may disturb microvascular water exchange in AD and examine the potential of a relatively new imaging technique, dynamic contrast-enhanced MRI, to quantify water exchange on a cellular level and thus serve as a probe of BBB integrity in AD.
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Kitaguchi H, Tomimoto H, Ihara M, Shibata M, Uemura K, Kalaria RN, Kihara T, Asada-Utsugi M, Kinoshita A, Takahashi R. Chronic cerebral hypoperfusion accelerates amyloid beta deposition in APPSwInd transgenic mice. Brain Res 2009; 1294:202-10. [PMID: 19646974 DOI: 10.1016/j.brainres.2009.07.078] [Citation(s) in RCA: 81] [Impact Index Per Article: 5.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/18/2009] [Revised: 07/21/2009] [Accepted: 07/22/2009] [Indexed: 11/19/2022]
Abstract
Chronic cerebral ischemia may accelerate clinicopathological changes in Alzheimer's disease. We have examined whether chronic cerebral hypoperfusion accelerates amyloid beta deposition in amyloid protein precursor transgenic (APP-Tg) mouse. At 5, 8, and 11 months of age, C57Bl/6J male mice overexpressing a mutant form of the human APP bearing the both Swedish (K670N/M671L) and the Indiana (V717F) mutations (APPSwInd) and their litterrmates were subjected to either sham operation or bilateral carotid artery stenosis (BCAS) using microcoils with an internal diameter of 0.18 mm (short-period group). One month after the sham operation or BCAS, these animals were examined by immunohistochemistry for glial fibrillary acidic protein, amyloid beta(1-40) (Abeta(1-40)), amyloid beta(1-42) (Abeta(1-42)), as well as Western blotting and filter assay for Abeta. Another batch of the littermates of APPSwInd mice were subjected to either sham operation or BCAS at 3 months and were examined in the same manner after survival for 9 months (long-period group). In the BCAS-treated group, the white matter was rarefied and astroglia was proliferated. Amyloid beta(1-40) immunoreactivity was found in a few axons in the white matter after BCAS, whereas Abeta(1-42) was accumulated in the scattered cortical neurons and the axons at ages of 6 months and thereafter in the short- and long-period groups. In the neuropil, both Abeta(1-40) and Abeta(1-42) were deposited in the sham-operated and BCAS-treated mice at ages of 9 and 12 months. There were no differences between the short-period group at ages of 12 months and the long-period group. Filter assay showed an increase of Abeta fibrils in the extracellular enriched fraction. Taken together, chronic cerebral hypoperfusion increased Abeta fibrils and induced Abeta deposition in the intracellular compartment and, therefore, may accelerate the pathological changes of Alzheimer's disease.
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Affiliation(s)
- Hiroshi Kitaguchi
- Department of Neurology, Kyoto University, Sakyo-ku, Kyoto 606-8504, Japan
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Affiliation(s)
- Charlie S. Thompson
- From the Division of Neurology, University of Ottawa, Neuroscience Research, The Ottawa Health Research Institute, the Canadian Stroke Network, and The Heart & Stroke Foundation Centre for Stroke Recovery, Ottawa, Ontario, Canada
| | - Antoine M. Hakim
- From the Division of Neurology, University of Ottawa, Neuroscience Research, The Ottawa Health Research Institute, the Canadian Stroke Network, and The Heart & Stroke Foundation Centre for Stroke Recovery, Ottawa, Ontario, Canada
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Tripathy D, Grammas P. Acetaminophen protects brain endothelial cells against oxidative stress. Microvasc Res 2009; 77:289-96. [PMID: 19265712 DOI: 10.1016/j.mvr.2009.02.002] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/12/2008] [Revised: 02/17/2009] [Accepted: 02/18/2009] [Indexed: 01/06/2023]
Abstract
Increasing evidence suggests that acetaminophen has unappreciated anti-oxidant and anti-inflammatory properties. Drugs that affect oxidant and inflammatory stress in the brain are of interest because both processes are thought to contribute to the pathogenesis of neurodegenerative disease. The objective of this study is to determine whether acetaminophen affects the response of brain endothelial cells to oxidative stress. Cultured brain endothelial cells are pre-treated with acetaminophen and then exposed to the superoxide-generating compound menadione (25 microM). Cell survival, inflammatory protein expression, and anti-oxidant enzyme activity are measured. Menadione causes a significant (p<0.001) increase in endothelial cell death as well as an increase in RNA and protein levels of tumor necrosis factor alpha, interleukin-1, macrophage inflammatory protein alpha, and RANTES. Menadione also evokes a significant (p<0.001) increase in the activity of the anti-oxidant enzyme superoxide dismutase (SOD). Pre-treatment of endothelial cell cultures with acetaminophen (25-100 microM) increases endothelial cell survival and inhibits menadione-induced expression of inflammatory proteins and SOD activity. In addition, we document, for the first time, that acetaminophen increases expression of the anti-apoptotic protein Bcl2. Suppressing Bcl2 with siRNA blocks the pro-survival effect of acetaminophen. These data show that acetaminophen has anti-oxidant and anti-inflammatory effects on the cerebrovasculature and suggest a heretofore unappreciated therapeutic potential for this drug in neurodegenerative diseases such as Alzheimer's disease that are characterized by oxidant and inflammatory stress.
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Affiliation(s)
- Debjani Tripathy
- Garrison Institute on Aging, Texas Tech University Health Sciences Center, 3601 4th Street Stop 9424, Lubbock, TX 79430, USA
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Tchantchou F, Shea TB. Chapter 3 Folate Deprivation, the Methionine Cycle, and Alzheimer's Disease. FOLIC ACID AND FOLATES 2008; 79:83-97. [DOI: 10.1016/s0083-6729(08)00403-2] [Citation(s) in RCA: 13] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 12/15/2022]
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22
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Alves TCTF, Rays J, Telles RMS, Júnior RF, Wajngarten M, Romano BW, Watanabe C, Busatto GF. Effects of Antidepressant Treatment on Cognitive Performance in Elderly Subjects With Heart Failure and Comorbid Major Depression: An Exploratory Study. PSYCHOSOMATICS 2007; 48:22-30. [PMID: 17209146 DOI: 10.1176/appi.psy.48.1.22] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/30/2022]
Abstract
Cognitive deficits are common in association with heart failure (HF), and it is possible that their severity is magnified by the concomitant presence of major depressive disorder (MDD). Using the Cambridge Mental Disorders of the Elderly Examination battery, the authors compared the cognitive performance of MDD-HF subjects (N=20), nondepressed HF subjects (N=23), and healthy control subjects (N=18). Scores were lower in both HF groups relative to control subjects. In the MDD-HF group, there were significant cognitive improvements after antidepressant treatment. Cognitive impairment is, therefore, significant in HF subjects with or without comorbid MDD, and it is important to recognize and treat MDD symptoms associated with HF.
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Affiliation(s)
- Tânia C T F Alves
- Department of Psychiatry, University of São Paulo Medical School, São Paulo, Brazil.
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Alves TCDTF, Busatto GF. Regional cerebral blood flow reductions, heart failure and Alzheimer's disease. Neurol Res 2006; 28:579-87. [PMID: 16945208 DOI: 10.1179/016164106x130416] [Citation(s) in RCA: 35] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVES To discuss whether there are similarities between the functional brain abnormalities detectable in association with the diagnoses of heart failure (HF) and Alzheimer's disease (AD), focusing particularly on neuroimaging findings in vivo. METHODS Using an electronic database (Medline), we reviewed imaging studies that have evaluated resting cerebral blood flow (CBF), resting glucose metabolism or amyloid deposition in groups of subjects suffering AD or HF compared with healthy controls. RESULTS Single photon emission computed tomography (SPECT) investigations have reported global CBF reductions in HF groups compared with controls. In one recent SPECT study using modern voxel-based methods for image analysis, regional CBF deficits in the pre-cuneus and posterior cingulate gyrus were detected in a sample of HF sufferers relative to controls. The regional distribution of functional deficits in the latter study was similar to that found in many positron emission tomography (PET) investigations of glucose metabolism at early AD stages, as well as in recent PET investigations of amyloid deposition in AD. DISCUSSION Imaging studies have rarely investigated whether there are localized functional brain deficits in association with HF. Recent regional CBF SPECT data provide preliminary anatomic support to a view that AD-like brain changes may develop in HF patients, possibly as a consequence of chronic CBF reductions. Additional studies of larger HF samples are needed to confirm this possibility, preferably using PET measures that have afforded greater sensitivity and specificity to identify brain functional abnormalities associated with the diagnosis of AD, such as indices of glucose metabolism and amyloid deposition.
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Roriz-Cruz M, Rosset I, Wada T, Sakagami T, Ishine M, De Sá Roriz-Filho J, Cruz TRS, Hosseinkhani M, Rodrigues RP, Sudoh S, Arai H, Wakatsuki Y, Souza AC, Nakagawa M, Kita T, Matsubayashi K. Cognitive impairment and frontal-subcortical geriatric syndrome are associated with metabolic syndrome in a stroke-free population. Neurobiol Aging 2006; 28:1723-36. [PMID: 16962212 DOI: 10.1016/j.neurobiolaging.2006.07.013] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/23/2006] [Revised: 07/07/2006] [Accepted: 07/17/2006] [Indexed: 02/08/2023]
Abstract
BACKGROUND Metabolic syndrome (Met.S) consists of a conglomeration of obesity, hypertension, glucose intolerance, and dislipidemia. Frontal-subcortical geriatric syndrome (FSCS) is caused by ischemic disruption of the frontal-subcortical network. It is unknown if Met.S is associated with FSCS. METHODS We evaluated 422 community-dwelling elderly (> or =60) in Brazil. FSCS was defined as the presence of at least one frontal release sign (grasping, palmomental, snout, or glabellar) plus coexistence of > or =3 the following criteria: (1) cognitive impairment, (2) late-onset depression, (3) neuromotor dysfunction, and (4) urgency incontinence. All values were adjusted to age and gender. RESULTS Met.S was present in 39.3% of all subjects. Cases without any of the FSCS components represented 37.2% ('successful neuroaging' group). People with 1-3 of the FSCS components ('borderline pathological neuroaging' group) were majority (52.6%), whereas those with 4-5 of these components (FSCS group) were minority (10.2%). Met.S was significantly associated with FSCS (OR=5.9; CI: 1.5-23.4) and cognitive impairment (OR=2.2; CI: 1.1-4.6) among stroke-free subjects. Number of Met.S components explained 30.7% of the variance on the number of FSCS criteria (P<0.001). If Met.S were theoretically removed from this population, prevalence of FSCS would decline by 31.6% and that of cognitive impairment by 21.4%. CONCLUSIONS Met.S was significantly associated with a 5.9 and 2.2 times higher chance of FSCS and cognitive impairment, respectively. Met.S might be a major determinant of 'successful' or 'pathological' neuroaging in western societies.
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Tian J, Shi J, Smallman R, Iwatsubo T, Mann DMA. Relationships in Alzheimer's disease between the extent of Abeta deposition in cerebral blood vessel walls, as cerebral amyloid angiopathy, and the amount of cerebrovascular smooth muscle cells and collagen. Neuropathol Appl Neurobiol 2006; 32:332-40. [PMID: 16640651 DOI: 10.1111/j.1365-2990.2006.00732.x] [Citation(s) in RCA: 45] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The relationship between degree of cerebral amyloid angiopathy (CAA) and the amount of smooth muscle cells (SMCs) and deposition of collagen IV fibres (COL IV) was investigated in the frontal and occipital cortex of 70 patients with autopsy confirmed Alzheimer's disease (AD). The extent of CAA was significantly greater in occipital than in frontal cortex, although SMC loss was greater in frontal than in occipital cortex. COL IV staining was significantly higher in occipital than in frontal cortex. The degree of SMC loss correlated with CAA, as Abeta40 but not as Abeta42 or total Abeta, in frontal cortex, but not in occipital cortex. Leptomeningeal arteries within occipital cortex showed significantly greater external diameter, greater wall thickness and greater luminal area than those in frontal cortex. The degree of CAA correlated with thickness of blood vessel wall and external diameter in frontal cortex, whereas extent of SMC loss correlated with thickness of blood vessel wall in occipital cortex. There were significant negative correlations between duration of disease and thickness of vessel wall, external diameter and luminal area. In patients with disease durations exceeding 10 years, external vessel diameter and thickness of the vessel wall were both halved compared with patients with durations less than 5 years; luminal area was reduced by about 75%. Blood vessels in AD undergo degenerative changes involving deposition of Abeta and COL IV with loss of SMC. SMC loss may relate to increasing Abeta deposition in early stages of disease, but this relationship may be lost with disease progression.
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Affiliation(s)
- J Tian
- Clinical Neuroscience Research Group, Faculty of Medical and Human Sciences, University of Manchester, Hope Hospital, Salford, UK
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26
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Lee H, Kim JM, Kim HJ, Lee I, Chang N. Folic acid supplementation can reduce the endothelial damage in rat brain microvasculature due to hyperhomocysteinemia. J Nutr 2005; 135:544-8. [PMID: 15735091 DOI: 10.1093/jn/135.3.544] [Citation(s) in RCA: 23] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/13/2022] Open
Abstract
To evaluate the effects of dietary folic acid supplementation on the cerebral vascular damage induced by hyperhomocysteinemia, rats were fed a diet containing 3.0 g/kg homocystine for 2 wk and then either 3.0 g/kg homocystine or 3.0 g/kg homocystine plus 0.008 g/kg folic acid for 8 wk. Control rats consumed the AIN-93 Maintenance diet throughout the experiment. The cerebral expression of glucose transporter-1 was measured by Western blot analysis and cerebrovascular structural alterations were evaluated by electron microscopy. The homocystine diet significantly increased the plasma levels of homocysteine and TBARS and decreased the cerebral expression of glucose transporter-1 (GLUT-1) with a concomitant increase in the percentage of damaged cerebral vessels. The inclusion of dietary folic acid for 8 wk caused plasma homocysteine levels to be the same as in control rats and it significantly upregulated the cerebral expression of GLUT-1 that was significantly reduced by hyperhomocysteinemia. Folic acid supplementation also significantly decreased the incidence of damaged vessels due to hyperhomocysteinemia. These results and the electron microscopy findings suggested that folic acid supplementation might reduce the detrimental effects on the endothelium caused by experimentally induced hyperhomocysteinemia.
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Affiliation(s)
- Hwayoung Lee
- Department of Anatomy, College of Medicine, Ewha Womans University, Seoul, Republic of Korea
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Hanson DR, Gottesman II. Theories of schizophrenia: a genetic-inflammatory-vascular synthesis. BMC MEDICAL GENETICS 2005; 6:7. [PMID: 15707482 PMCID: PMC554096 DOI: 10.1186/1471-2350-6-7] [Citation(s) in RCA: 195] [Impact Index Per Article: 10.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Subscribe] [Scholar Register] [Received: 07/26/2004] [Accepted: 02/11/2005] [Indexed: 12/13/2022]
Abstract
BACKGROUND Schizophrenia, a relatively common psychiatric syndrome, affects virtually all brain functions yet has eluded explanation for more than 100 years. Whether by developmental and/or degenerative processes, abnormalities of neurons and their synaptic connections have been the recent focus of attention. However, our inability to fathom the pathophysiology of schizophrenia forces us to challenge our theoretical models and beliefs. A search for a more satisfying model to explain aspects of schizophrenia uncovers clues pointing to genetically mediated CNS microvascular inflammatory disease. DISCUSSION A vascular component to a theory of schizophrenia posits that the physiologic abnormalities leading to illness involve disruption of the exquisitely precise regulation of the delivery of energy and oxygen required for normal brain function. The theory further proposes that abnormalities of CNS metabolism arise because genetically modulated inflammatory reactions damage the microvascular system of the brain in reaction to environmental agents, including infections, hypoxia, and physical trauma. Damage may accumulate with repeated exposure to triggering agents resulting in exacerbation and deterioration, or healing with their removal. There are clear examples of genetic polymorphisms in inflammatory regulators leading to exaggerated inflammatory responses. There is also ample evidence that inflammatory vascular disease of the brain can lead to psychosis, often waxing and waning, and exhibiting a fluctuating course, as seen in schizophrenia. Disturbances of CNS blood flow have repeatedly been observed in people with schizophrenia using old and new technologies. To account for the myriad of behavioral and other curious findings in schizophrenia such as minor physical anomalies, or reported decreased rates of rheumatoid arthritis and highly visible nail fold capillaries, we would have to evoke a process that is systemic such as the vascular and immune/inflammatory systems. SUMMARY A vascular-inflammatory theory of schizophrenia brings together environmental and genetic factors in a way that can explain the diversity of symptoms and outcomes observed. If these ideas are confirmed, they would lead in new directions for treatments or preventions by avoiding inducers of inflammation or by way of inflammatory modulating agents, thus preventing exaggerated inflammation and consequent triggering of a psychotic episode in genetically predisposed persons.
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Affiliation(s)
- Daniel R Hanson
- Department of Psychiatry, VA Medical Center (116A), One Veterans Drive, Minneapolis, MN, 55417 and Departments of Psychiatry & Psychology, University of Minnesota, USA
| | - Irving I Gottesman
- Departments of Psychiatry & Psychology, University of Minnesota, Minneapolis, MN 55454, USA
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Vega E, Gómez-Villalobos MDJ, Flores G. Alteration in dendritic morphology of pyramidal neurons from the prefrontal cortex of rats with renovascular hypertension. Brain Res 2004; 1021:112-8. [PMID: 15328038 DOI: 10.1016/j.brainres.2004.06.042] [Citation(s) in RCA: 42] [Impact Index Per Article: 2.1] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Accepted: 06/27/2004] [Indexed: 10/26/2022]
Abstract
We have studied, in the rat, the dendritic morphological changes of the pyramidal neurons of the medial part of the prefrontal cortex induced by the chronic effect of high blood pressure. Renovascular hypertension was induced using a silver clip on the renal artery by surgery. The morphology of the pyramidal neurons from the medial part of the prefrontal cortex was investigated in these animals. The blood pressure was measured to confirm the increase in the arterial blood pressure. After 16 weeks of increase in the arterial blood pressure, the animals were sacrificed by overdoses of sodium pentobarbital and perfused intracardially with a 0.9% saline solution. The brains were removed, processed by the Golgi-Cox stain method and analyzed by the Sholl method. The dendritic morphology clearly showed that the hypertensive animals had an increase (32%) in the dendritic length of the pyramidal cells with a decrease (50%) in the density of dendritic spines when compared with sham animals. The branch-order analysis showed that the animals with hypertension exhibit more dendritic arborization at the level of the first to fourth branch order. This result suggests that renovascular hypertension may in part affect the dendritic morphology in this limbic structure, which may implicate cognitive impairment in hypertensive patients.
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Affiliation(s)
- Elenia Vega
- Escuela de Biología, Universidad Autónoma de Puebla, Puebla, México
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de Moraes SA, Szklo M, Tilling K, Sato R, Knopman D. Cognitive Functioning as a Predictor of Ischemic Stroke Incidence. Epidemiology 2003; 14:673-9. [PMID: 14569182 DOI: 10.1097/01.ede.0000083262.58396.a3] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
BACKGROUND Some studies have suggested that cognitive impairment is related to subsequent stroke incidence. The present study investigated the role of cognitive impairment as a predictor of ischemic stroke incidence in the Atherosclerosis Risk in Communities (ARIC) cohort. METHODS The study population consisted of 11,958 men and women 48-67 years of age in 4 U.S. communities, followed from January 1, 1990 through December 31, 1997. Cognitive performance was evaluated at the second (1990-1992) visit of the ARIC Study using 3 instruments. We identified incident strokes by means of hospital record and death certificate reviews, as well as annual telephone follow up. RESULTS We found no consistent associations or trends between any of the cognitive test results and ischemic stroke incidence after multiple adjustment for confounding variables. Hazard ratios for the lowest compared with the highest quartiles were 1.5 (95% confidence interval [CI] = 0.9-2.6), 1.1 (95% CI = 0.6-2.1), and 1.0 (95% CI = 0.6-1.8) for the Delayed Word Recall Test, Digit Symbol Subtest of the Wechsler Adult Intelligence Scale-Revised, and Word Fluency Test, respectively. CONCLUSIONS The findings of the present study of relatively young subjects did not replicate the association between cognitive impairment and stroke incidence found in studies in older populations. This could be the result of the younger ages of our cohort members or the differences in cognitive tests.
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Affiliation(s)
- Suzana Alves de Moraes
- Department of Epidemiology, School of Hygiene and Public Health, The Johns Hopkins University, Baltimore, MD 21205, USA.
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Frishman WH. Are antihypertensive agents protective against dementia? A review of clinical and preclinical data. HEART DISEASE (HAGERSTOWN, MD.) 2002; 4:380-6. [PMID: 12441015 DOI: 10.1097/00132580-200211000-00007] [Citation(s) in RCA: 28] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/25/2022]
Abstract
In the United States, the size of the population of persons aged 65 years or older is expected to double within the next 30 years, resulting in a marked increase in the prevalence of dementia. Hypertension is a risk factor for cognitive impairment and dementia in addition to cerebrovascular morbidity and mortality. The evidence for a connection between high blood pressure in midlife and dementia in late life comes from numerous longitudinal studies. A placebo-controlled, double-blind, randomized trial involving 2,418 patients aged 60 years or older with isolated systolic hypertension demonstrated that active treatment based on the dihydropyridine calcium antagonist nitrendipine with the addition of enalapril, hydrochlorothiazide, or both if needed to control systolic blood pressure to <150 mmHg, significantly reduced not only stroke and cardiovascular complications but also the incidence of vascular dementia and Alzheimer's disease. Several trials of antihypertensive treatment are ongoing to confirm this important finding. The newer dihydropyridine calcium antagonists lacidipine and lercanidipine are effective and well tolerated in the treatment of hypertension. In animal models, these newer agents also have been shown to prevent the progression of hypertensive microvascular damage. Their neuroprotective effects offer possible unique advantages in the management of hypertension.
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Affiliation(s)
- William H Frishman
- Department of Medicine, New York Medical College, Westchester Medical Center, Valhalla, New York 10595, USA.
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Kim JM, Lee H, Chang N. Hyperhomocysteinemia due to short-term folate deprivation is related to electron microscopic changes in the rat brain. J Nutr 2002; 132:3418-21. [PMID: 12421861 DOI: 10.1093/jn/132.11.3418] [Citation(s) in RCA: 38] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/14/2022] Open
Abstract
We investigated the effects of folate deprivation on plasma folate and homocysteine and its effects on cerebral microvasculature using electron microscopy. Two levels of folic acid (0 mg and 4 mg/kg diet) were fed to 6-mo-old male rats for 8 wk. Dietary folate deprivation decreased plasma folate from 353.0 +/- 29.7 nmol/L to 44.2 +/- 7.2 nmol/L with a concomitant increase in plasma homocysteine from 6.15 +/- 0.9 micro mol/L to 19.5 +/- 2.7 micro mol/L. Plasma folate was negatively correlated with plasma homocysteine at wk 8 (r = -0.876, P = 0.004). Electron microscopic studies of the brains of folate-deprived rats revealed cytoplasmic swelling and mitochondrial degeneration in the endothelium, perivascular amorphous fibrosis and pericytic degenerative appearance in the cerebrocortical microvascular wall. These morphologic changes might be helpful for elucidating the mechanisms underlying the cerebrovascular and neuropathology with folate deficiency.
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Affiliation(s)
- Ji-myung Kim
- Department of Food and Nutritional Sciences, Department of Anatomy, College of Medicine, Ewha Womans University, Seoul, Korea
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Alves de Moraes S, Szklo M, Knopman D, Sato R. The relationship between temporal changes in blood pressure and changes in cognitive function: atherosclerosis risk in communities (ARIC) study. Prev Med 2002; 35:258-63. [PMID: 12202068 DOI: 10.1006/pmed.2002.1077] [Citation(s) in RCA: 33] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 12/25/2022]
Abstract
BACKGROUND Although previous epidemiological studies have reported that hypertension is a major risk factor for decline in brain perfusion and atrophy, which are known to be related to cognitive decline, the impact of temporal changes in blood pressure on age-related cognitive declines has not been assessed. METHODS The present study evaluates changes in blood pressure and cognitive decline over a 6-year period in the Atherosclerosis Risk in Communities (ARIC) Study. This report is based on 8,058 men and women aged 48-67 years examined in the second (1990-92), and fourth (1996-98) ARIC cohort visits. Changes between these visits were measured in hypertension status and three cognitive function tests: Delayed Word Recall (DWR), the Digit Symbol Subtest of the Wechsler Adult Intelligence Scale-Revised (DSS/WAIS-R), and the Word Fluency (WF). Adjusted mean differences in cognitive function were compared among five categories of hypertension status by using linear regression modeling. RESULTS In the present study, older subjects with uncontrolled hypertension had a significantly larger mean DSS/WAIS-R score decline than normotensive subjects. Although other cognitive declines did not achieve statistical significance, both cross-sectional and change analysis suggested that partially controlled or uncontrolled hypertension is associated with a less favorable cognitive profile, particularly when considering results of the DSS and the WF tests. CONCLUSIONS The present study results provide some support to the hypothesis that hypertension status changes over 6 years in individuals initially aged 48-67 years are related to cognitive changes.
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Affiliation(s)
- Suzana Alves de Moraes
- Department of Epidemiology, School of Hygiene and Public Health, The Johns Hoipkins University, 615 N Wolfe Street, Room W6009, Baltimore, MD 21205, USA.
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de Wilde MC, Farkas E, Gerrits M, Kiliaan AJ, Luiten PGM. The effect of n-3 polyunsaturated fatty acid-rich diets on cognitive and cerebrovascular parameters in chronic cerebral hypoperfusion. Brain Res 2002; 947:166-73. [PMID: 12176157 DOI: 10.1016/s0006-8993(02)02695-1] [Citation(s) in RCA: 55] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
Western diets consist to a large part of n-6 polyunsaturated fatty acids (PUFAs). These n-6 PUFAs and their conversion products favor immune and inflammatory reactions and compromise vasoregulation, which can contribute to the development of dementia. Recent epidemiological studies associated dementia, particularly the type accompanied by a vascular component, with high, saturated dietary fat intake. Conversely, high fish consumption (a source of long chain n-3 PUFAs) was related to a reduced risk for cognitive decline. Therefore we studied the effects of long chain n-3 PUFAs in rats with bilateral occlusion of the common carotid arteries (2VO), which mimics cerebral hypoperfusion, a risk factor for dementia. Male Wistar rats received experimental diets with a decreased (n-6)/(n-3) ratio from weaning on. At the age of 3 months, the animals underwent 2VO surgery. The rats were tested in the elevated plus maze, an active avoidance paradigm and the Morris water maze (at different survival times). Following behavioral testing, the animals were sacrificed at the age of 7 months. The frontoparietal cortex was analyzed for capillary ultrastructure with electron microscopy. No effects of cerebral hypoperfusion or diet were found on elevated plus maze and active avoidance, while spatial memory in the Morris maze was compromised due to cerebral hypoperfusion under placebo dietary conditions. n-3 PUFA supplementation in combination with extra additives improved the performance of the 2VO animals. The number of endothelial mitochondria, as well as the ratio of microvessels with degenerative pericytes appeared to be lower due to long chain n-3 PUFAs. These results may indicate an improved condition of the blood-brain barrier.
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Affiliation(s)
- Martijn C de Wilde
- Department of Animal Physiology, Workgroup of Molecular Neurobiology, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands
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Carmeliet P, Storkebaum E. Vascular and neuronal effects of VEGF in the nervous system: implications for neurological disorders. Semin Cell Dev Biol 2002; 13:39-53. [PMID: 11969370 DOI: 10.1006/scdb.2001.0290] [Citation(s) in RCA: 182] [Impact Index Per Article: 8.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
Vascular endothelial growth factor (VEGF) was originally discovered as an endothelial-specific growth factor. While the predominant role of this growth factor in the formation of new blood vessels (angiogenesis) is unquestioned, recent observations indicate that VEGF also has direct effects on neurons and glial cells, and stimulates their growth, survival and axonal outgrowth. Because of these pleiotropic effects, VEGF has now been implicated in several neurological disorders both in the preterm infant (leukomalacia) and the adult (stroke, neurodegeneration, cerebral and spinal trauma, ischemic and diabetic neuropathy, nerve regeneration). A challenge for the future is to unravel to what extent the effect of VEGF in these disorders relates to its angiogenic activity or direct neurotrophic effect.
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Affiliation(s)
- Peter Carmeliet
- Center for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute for Biotechnology, University of Leuven, Belgium.
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Abstract
Numerous physiological conditions as well as behavioral conditions have been shown to influence central nervous system vascular structure. Many of the methods used to investigate these structural alterations take advantage of the visibility of viscous substances (e.g. India ink in gelatin) perfused into the vasculature. The high viscosity of the solution, however, can cause incomplete vessel perfusion. The aim of the present study was to test whether or not capillaries seen in tissue perfused with fixative, embedded in celloidin and stained with Methylene Blue-Azure II (n=6) could be a useful alternative for the investigation of brain vascular structure. The method was compared to tissue from six rats perfused with India ink in gelatin and stained with cresyl violet. Qualitatively, vessels in the standard perfused tissue embedded in celloidin yielded clear vessels with stained pericytes. The two methods did not differ in branch point to cell ratio, length of individual capillaries, vessel length per mm(3), and capillary tortuosity. The capillary diameter was greater in the celloidin embedded tissue than in the India ink perfused tissue. Measuring the diameter between vessel walls appears to provide a more accurate measure than the widest distance between India ink pigments. Quantitative comparisons suggest that perfusion with standard fixative followed by embedding in celloidin provides vascular quantification comparable to that from India ink perfused tissue. The present method has several advantages, which include visualization of pericytes, increased probability of complete perfusion, clear view of cells that might otherwise be obscured by opaque vessels, and the possibility of using the alternate cerebral hemisphere for investigation of vascular ultrastructure.
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Affiliation(s)
- D A Tata
- Department of Psychology, State University of New York at Stony Brook, Stony Brook, New York, NY 11794-2500, USA
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Abstract
The aging of the central nervous system and the development of incapacitating neurological diseases like Alzheimer's disease (AD) are generally associated with a wide range of histological and pathophysiological changes eventually leading to a compromised cognitive status. Although the diverse triggers of the neurodegenerative processes and their interactions are still the topic of extensive debate, the possible contribution of cerebrovascular deficiencies has been vigorously promoted in recent years. Various forms of cerebrovascular insufficiency such as reduced blood supply to the brain or disrupted microvascular integrity in cortical regions may occupy an initiating or intermediate position in the chain of events ending with cognitive failure. When, for example, vasoconstriction takes over a dominating role in the cerebral vessels, the perfusion rate of the brain can considerably decrease causing directly or through structural vascular damage a drop in cerebral glucose utilization. Consequently, cerebral metabolism can suffer a setback leading to neuronal damage and a concomitant suboptimal cognitive capacity. The present review focuses on the microvascular aspects of neurodegenerative processes in aging and AD with special attention to cerebral blood flow, neural metabolic changes and the abnormalities in microvascular ultrastructure. In this context, a few of the specific triggers leading to the prominent cerebrovascular pathology, as well as the potential neurological outcome of the compromised cerebral microvascular system are also going to be touched upon to a certain extent, without aiming at total comprehensiveness. Finally, a set of animal models are going to be presented that are frequently used to uncover the functional relationship between cerebrovascular factors and the damage to neural networks.
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Affiliation(s)
- E Farkas
- Department of Animal Physiology, Graduate School of Behavioral and Cognitive Neurosciences, University of Groningen, P.O. Box 14, 9750 AA Haren, The Netherlands.
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Farkas E, De Jong GI, Apró E, Keuker JI, Luiten PG. Calcium antagonists decrease capillary wall damage in aging hypertensive rat brain. Neurobiol Aging 2001; 22:299-309. [PMID: 11182480 DOI: 10.1016/s0197-4580(00)00225-6] [Citation(s) in RCA: 34] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/16/2022]
Abstract
Chronic hypertension during aging is a serious threat to the cerebral vasculature. The larger brain arteries can react to hypertension with an abnormal wall thickening, a loss of elasticity and a narrowed lumen. However, little is known about the hypertension-induced alterations of cerebral capillaries. The present study describes ultrastructural alterations of the cerebrocortical capillary wall, such as thickening and collagen accumulation in the basement membrane of aging spontaneously hypertensive stroke-prone rats. The ratio of cortical capillaries with such vascular pathology occurred significantly more frequently in hypertensive animals. Nimodipine and nifedipine are potential drugs to decrease blood pressure in hypertension but their beneficial effects in experimental studies reach beyond the control of blood pressure. Nimodipine and nifedipine can alleviate ischemia-related symptoms and improve cognition. These drugs differ in that nifedipine, but not nimodipine reduces blood pressure at the here-used concentration while both drugs can penetrate the blood-brain barrier. Here we show that chronic treatment of aging hypertensive stroke-prone rats with nimodipine or nifedipine could preserve microvascular integrity in the cerebral cortex.
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Affiliation(s)
- E Farkas
- Department of Animal Physiology, Graduate School of Behavioral and Cognitive Neurosciences, University of Groningen, P.O.B. 14, 9750 AA, Haren, The Netherlands.
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Farkas E, De Vos RA, Jansen Steur EN, Luiten PG. Are Alzheimer's disease, hypertension, and cerebrocapillary damage related? Neurobiol Aging 2000; 21:235-43. [PMID: 10867208 DOI: 10.1016/s0197-4580(00)00122-6] [Citation(s) in RCA: 43] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
Abstract
Alzheimer's disease (AD) patients are often subject to vascular dysfunction besides their specific CNS pathology, which warrants further examination of the interaction between vascular factors and the development of dementia. The association of decreased cerebral blood flow (CBF) or hypertension with AD has been a target of growing interest. Parallel with physiological changes, the cerebral capillaries in AD are also prone to degenerative processes. The microvascular abnormalities that are the result of such degeneration may be the morphological correlates of the vascular pathophysiology pointing to a compromised nutrient transport through the capillaries. Animal models have been developed to study the consequences of hypertension and reduced CBF. Spontaneously hypertensive rats are widely used in hypertension research whereas ligation of the carotid arteries has become a method to produce cerebral hypoperfusion. Based on these models, we propose a relationship between hypertension, cerebral hypoperfusion, cerebral capillary malformation and cognitive decline as it occurs in AD. We suggest that the above conditions are functionally related and can contribute to the progression of AD.
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Affiliation(s)
- E Farkas
- Department of Animal Physiology, Graduate School of Behavioral and Cognitive Neurosciences, University of Groningen, Groningen, The Netherlands.
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