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Umegaki H, Iimuro S, Shinozaki T, Araki A, Sakurai T, Iijima K, Ohashi Y, Ito H. Risk factors associated with cognitive decline in the elderly with type 2 diabetes: Pooled logistic analysis of a 6-year observation in the Japanese elderly diabetes intervention trial. Geriatr Gerontol Int 2012; 12 Suppl 1:110-6. [DOI: 10.1111/j.1447-0594.2011.00818.x] [Citation(s) in RCA: 30] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/08/2023]
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Kugaevskaya EV. Angiotensin converting enzyme and Alzheimer’s disease. BIOCHEMISTRY MOSCOW-SUPPLEMENT SERIES B-BIOMEDICAL CHEMISTRY 2012. [DOI: 10.1134/s199075081201009x] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 11/23/2022]
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53
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Kokjohn TA, Maarouf CL, Roher AE. Is Alzheimer's disease amyloidosis the result of a repair mechanism gone astray? Alzheimers Dement 2011; 8:574-83. [PMID: 22047632 DOI: 10.1016/j.jalz.2011.05.2429] [Citation(s) in RCA: 16] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/13/2011] [Accepted: 05/17/2011] [Indexed: 01/21/2023]
Abstract
Here, we synthesize several lines of evidence supporting the hypothesis that at least one function of amyloid-β is to serve as a part of the acute response to brain hemodynamic disturbances intended to seal vascular leakage. Given the resilient and adhesive physicochemical properties of amyloid, an abluminal hemostatic repair system might be highly advantageous, if deployed on a limited and short-term basis, in young individuals. However, in the aged, inevitable cardiovascular dysfunction combined with brain microvascular lesions may yield global chronic hypoperfusion that may lead to continuous amyloid deposition and consequential negative effects on neuronal viability. A large body of experimental evidence supports the hypothesis of an amyloid-β rescue function gone astray. Preventing or inducing the removal of amyloid in Alzheimer's disease (AD) has been simultaneously successful and disappointing. Amyloid deposits clearly play major roles in AD, but they may not represent the preeminent factor in dementia pathogenesis. Successful application of AD preventative approaches may hinge on an accurate and comprehensive view of comorbidities, including cardiovascular disease, diabetes, and head trauma.
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Affiliation(s)
- Tyler A Kokjohn
- The Longtine Center for Neurodegenerative Biochemistry, Banner Sun Health Research Institute, Sun City, AZ, USA
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Zhu H, Zhang J, Sun H, Zhang L, Liu H, Zeng X, Yang Y, Yao Z. An enriched environment reverses the synaptic plasticity deficit induced by chronic cerebral hypoperfusion. Neurosci Lett 2011; 502:71-5. [PMID: 21524687 DOI: 10.1016/j.neulet.2011.04.015] [Citation(s) in RCA: 31] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/23/2011] [Revised: 03/17/2011] [Accepted: 04/08/2011] [Indexed: 11/17/2022]
Abstract
Chronic cerebral hypoperfusion (CCH) leads to a long-term, inadequate blood supply in the brain, which eventually causes cognitive impairment. An enriched environment (EE) improves learning and memory by improving synaptic plasticity. The impact of an EE on cognitive impairment induced by CCH is not, however, well known. To investigate this possible effect, we permanently occluded the bilateral common carotid arteries (2-vessel occlusion) in rats to induce CCH and studied EE effects on cognitive impairment and synaptic plasticity following CCH. We found that EE treatment reversed spatial memory deficits induced by CCH. An EE also reversed the deficit in long-term potentiation following CCH, but the input-output curves and paired-pulse facilitation were not affected. CCH led to reduced expression of phosphorylated CREB in the rats, but EE reversed this reduction. In addition, CCH reduced the expression of synaptophysin and microtubule-associated protein 2, whereas EE reversed this reduced expression. Thus, EE reversed CCH-induced spatial cognitive impairment without affecting basal synaptic transmission or the release probability of presynaptic neurotransmitters. The EE effect probably resulted from the regulation of postsynaptic potentiation.
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Affiliation(s)
- Hong Zhu
- Department of Neurology, Zhongnan Hospital, Wuhan University, No. 169 Donghu Road, Wuchang District, Wuhan 430071, China
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Wang DC, Sun CH, Liu LY, Sun XH, Jin XW, Song WL, Liu XQ, Wan XL. Serum fatty acid profiles using GC-MS and multivariate statistical analysis: potential biomarkers of Alzheimer's disease. Neurobiol Aging 2010; 33:1057-66. [PMID: 20980076 DOI: 10.1016/j.neurobiolaging.2010.09.013] [Citation(s) in RCA: 73] [Impact Index Per Article: 5.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/01/2010] [Revised: 09/02/2010] [Accepted: 09/16/2010] [Indexed: 11/15/2022]
Abstract
Previous studies showed the relationship between fatty acids and the risk of developing Alzheimer's disease (AD). However, they did not address potential differences in free fatty acid (FFA) profiles that could be used to distinguish between AD patients and healthy controls. In the present study we used gas chromatography-mass spectrometry (GC-MS) technology coupled with multivariate statistical analysis to study profiles of FFA in AD. The results indicated 2 saturated fatty acids (C14:0 and C16:0; p < 0.001 and p < 0.05, respectively), 3 unsaturated fatty acids (C18:1, C18:3, and C22:6; p < 0.05, p < 0.05, and p < 0.001, respectively), where mean levels in serum from AD patients were significantly lower than controls. Partial least squares discriminant analysis (PLS-DA) models with unit variance (UV) scaling and orthogonal signal correction (OSC) data preprocessing methods were employed to refine intergroup differences between FFA profiles. The results of the analysis have highlighted docosahexaenoic acid (DHA) as the FFA with the greatest potential as a biomarker of AD, and this study has demonstrated that FFA biomarkers have considerable potential in diagnosing and monitoring AD.
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Affiliation(s)
- De-Cai Wang
- Public Health College, Harbin Medical University, Harbin, China.
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56
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Ferrer I. Cognitive impairment of vascular origin: neuropathology of cognitive impairment of vascular origin. J Neurol Sci 2010; 299:139-49. [PMID: 20846674 DOI: 10.1016/j.jns.2010.08.039] [Citation(s) in RCA: 47] [Impact Index Per Article: 3.4] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/17/2010] [Revised: 08/15/2010] [Accepted: 08/24/2010] [Indexed: 12/31/2022]
Abstract
The term cognitive impairment of vascular origin is used to designate global cognitive deficits as well as focal neurological deficits such as aphasia, apraxia and agnosia of vascular/circulatory origin. It has been useful for identifying early clinical and neuroradiological alterations that might permit therapeutic strategies geared to curbing the progression of cerebrovascular disease. Multi-infarct encephalopathy, infarcts in strategic areas, lacunae and lacunar status, Binswanger's encephalopathy, hippocampal sclerosis, cortical granular atrophy and watershed infarcts are common lesions. Hypertension and vascular diseases such as arteriosclerosis, small blood vessel disease, inflammatory diseases of the blood vessels, Sneddon syndrome, cerebral amyloid angiopathies, cerebral autosomic dominant arteriopathy with subcortical infarcts and leukoencephalopathy (CADASIL), and Maeda's syndrome are causative of cognitive impairment of vascular origin. Other less common causes are hereditary endotheliopathy with retinopathy, neuropathy and strokes (HERNS), cerebro-retinian vasculopathy (CRV), hereditary vascular retinopathy (HVR) (all three linked to 3p21.1-p21.3), hereditary infantile hemiparesis with arteriolar retinopathy and leukoencephalopathy (HIHRATL) (not linked to 3p21), fibromuscular dysplasia, and moya-moya disease. Lack of uniformity of clinical manifestations, the variety of vascular diseases and circulatory factors, the diverse, but often convergent, neuropathological substrates, and the common association with unrelated neurodegenerative diseases in the elderly, make it hard to assume a single clinical approach in the diagnosis and treatment of cognitive impairment of vascular origin. Rather, environmental and genetic risk factors, underlying vascular diseases, associated systemic, metabolic and neurodegenerative diseases and identification of extent and distribution of lesions with morphological and functional neuroimaging methods should be applied in every individual patient.
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Affiliation(s)
- Isidre Ferrer
- Institut de Neuropatologia, Servei Anatomia Patològica, IDIBELL-Hospital Universitari de Bellvitge, 08907 Hospitalet de LLobregat, Spain.
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Abstract
Serum response factor (SRF) is a ubiquitously expressed transcription factor that binds to a DNA cis element known as the CArG box, which is found in the proximal regulatory regions of over 200 experimentally validated target genes. Genetic deletion of SRF is incompatible with life in a variety of animals from different phyla. In mice, loss of SRF throughout the early embryo results in gastrulation defects precluding analyses in individual organ systems. Genetic inactivation studies using conditional or inducible promoters directing the expression of the bacteriophage Cre recombinase have shown a vital role for SRF in such cellular processes as contractility, cell migration, synaptic activity, inflammation, and cell survival. A growing number of experimental and human diseases are associated with changes in SRF expression, suggesting that SRF has a role in the pathogenesis of disease. This review summarizes data from experimental model systems and human pathology where SRF expression is either deliberately or naturally altered.
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Hernandez-Guillamon M, Mawhirt S, Fossati S, Blais S, Pares M, Penalba A, Boada M, Couraud PO, Neubert TA, Montaner J, Ghiso J, Rostagno A. Matrix metalloproteinase 2 (MMP-2) degrades soluble vasculotropic amyloid-beta E22Q and L34V mutants, delaying their toxicity for human brain microvascular endothelial cells. J Biol Chem 2010; 285:27144-27158. [PMID: 20576603 PMCID: PMC2930713 DOI: 10.1074/jbc.m110.135228] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2010] [Revised: 06/21/2010] [Indexed: 11/06/2022] Open
Abstract
Patients carrying mutations within the amyloid-beta (Abeta) sequence develop severe early-onset cerebral amyloid angiopathy with some of the related variants manifesting primarily with hemorrhagic phenotypes. Matrix metalloproteases (MMPs) are typically associated with blood brain barrier disruption and hemorrhagic transformations after ischemic stroke. However, their contribution to cerebral amyloid angiopathy-related hemorrhage remains unclear. Human brain endothelial cells challenged with Abeta synthetic homologues containing mutations known to be associated in vivo with hemorrhagic manifestations (AbetaE22Q and AbetaL34V) showed enhanced production and activation of MMP-2, evaluated via Multiplex MMP antibody arrays, gel zymography, and Western blot, which in turn proteolytically cleaved in situ the Abeta peptides. Immunoprecipitation followed by mass spectrometry analysis highlighted the generation of specific C-terminal proteolytic fragments, in particular the accumulation of Abeta-(1-16), a result validated in vitro with recombinant MMP-2 and quantitatively evaluated using deuterium-labeled internal standards. Silencing MMP-2 gene expression resulted in reduced Abeta degradation and enhanced apoptosis. Secretion and activation of MMP-2 as well as susceptibility of the Abeta peptides to MMP-2 degradation were dependent on the peptide conformation, with fibrillar elements of AbetaE22Q exhibiting negligible effects. Our results indicate that MMP-2 release and activation differentially degrades Abeta species, delaying their toxicity for endothelial cells. However, taking into consideration MMP ability to degrade basement membrane components, these protective effects might also undesirably compromise blood brain barrier integrity and precipitate a hemorrhagic phenotype.
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Affiliation(s)
- Mar Hernandez-Guillamon
- Neurovascular Research Laboratory, Institut de Recerca, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | - Stephanie Mawhirt
- Department of Pathology, New York University School of Medicine, New York, New York 10016
| | - Silvia Fossati
- Department of Pathology, New York University School of Medicine, New York, New York 10016
| | - Steven Blais
- Department of Pharmacology, , New York University School of Medicine, New York, New York 10016; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York 10016
| | - Mireia Pares
- Neurovascular Research Laboratory, Institut de Recerca, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | - Anna Penalba
- Neurovascular Research Laboratory, Institut de Recerca, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | - Merce Boada
- Neurovascular Unit, Department of Neurology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | | | - Thomas A Neubert
- Department of Pharmacology, , New York University School of Medicine, New York, New York 10016; Kimmel Center for Biology and Medicine at the Skirball Institute, New York University School of Medicine, New York, New York 10016
| | - Joan Montaner
- Neurovascular Research Laboratory, Institut de Recerca, Hospital Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain; Neurovascular Unit, Department of Neurology, Hospital Universitari Vall d'Hebron, Universitat Autònoma de Barcelona, 08035 Barcelona, Spain
| | - Jorge Ghiso
- Department of Pathology, New York University School of Medicine, New York, New York 10016; Department of Psychiatry, New York University School of Medicine, New York, New York 10016
| | - Agueda Rostagno
- Department of Pathology, New York University School of Medicine, New York, New York 10016.
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59
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Ward MA, Bendlin BB, McLaren DG, Hess TM, Gallagher CL, Kastman EK, Rowley HA, Asthana S, Carlsson CM, Sager MA, Johnson SC. Low HDL Cholesterol is Associated with Lower Gray Matter Volume in Cognitively Healthy Adults. Front Aging Neurosci 2010; 2. [PMID: 20725527 PMCID: PMC2914583 DOI: 10.3389/fnagi.2010.00029] [Citation(s) in RCA: 35] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/15/2010] [Accepted: 06/26/2010] [Indexed: 02/05/2023] Open
Abstract
Dyslipidemia is common in adults and contributes to high rates of cardiovascular disease and may be linked to subsequent neurodegenerative and neurovascular diseases. This study examined whether lower brain volumes and cognition associated with dyslipidemia could be observed in cognitively healthy adults, and whether apolipoprotein E (APOE) genotype or family history of Alzheimer's disease (FHAD) alters this effect. T1-weighted magnetic resonance imaging was used to examine regional brain gray matter (GM) and white matter (WM) in 183 individuals (58.4 ± 8.0 years) using voxel-based morphometry. A non-parametric multiple linear regression model was used to assess the effect of high-density lipoprotein (HDL) and non-HDL cholesterol, APOE, and FHAD on regional GM and WM volume. A post hoc analysis was used to assess whether any significant correlations found within the volumetric analysis had an effect on cognition. HDL was positively correlated with GM volume in the bilateral temporal poles, middle temporal gyri, temporo-occipital gyri, and left superior temporal gyrus and parahippocampal region. This effect was independent of APOE and FHAD. A significant association between HDL and the Brief Visuospatial Memory Test was found. Additionally, GM volume within the right middle temporal gyrus, the region most affected by HDL, was significantly associated with the Controlled Oral Word Association Test and the Center for Epidemiological Studies Depression Scale. These findings suggest that adults with decreased levels of HDL cholesterol may be experiencing cognitive changes and GM reductions in regions associated with neurodegenerative disease and therefore, may be at greater risk for future cognitive decline.
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Affiliation(s)
- Michael A Ward
- Geriatric Research, Education and Clinical Center, Wm. S. Middleton Memorial Veterans Hospital Madison, WI, USA
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60
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Jicha GA, Markesbery WR. Omega-3 fatty acids: potential role in the management of early Alzheimer's disease. Clin Interv Aging 2010; 5:45-61. [PMID: 20396634 PMCID: PMC2854051 DOI: 10.2147/cia.s5231] [Citation(s) in RCA: 103] [Impact Index Per Article: 7.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2010] [Indexed: 01/08/2023] Open
Abstract
Omega-3 fatty acids are essential for brain growth and development. They play an important role throughout life, as critical modulators of neuronal function and regulation of oxidative stress mechanisms, in brain health and disease. Docosahexanoic acid (DHA), the major omega-3 fatty acid found in neurons, has taken on a central role as a target for therapeutic intervention in Alzheimer’s disease (AD). A plethora of in vitro, animal model, and human data, gathered over the past decade, highlight the important role DHA may play in the development of a variety of neurological and psychiatric disorders, including AD. Cross sectional and prospective cohort data have demonstrated that reduced dietary intake or low brain levels of DHA are associated with accelerated cognitive decline or the development of incipient dementia, including AD. Several clinical trials investigating the effects of omega-3 fatty acid supplementation in AD have been completed and all failed to demonstrate its efficacy in the treatment of AD. However, these trials produced intriguing data suggesting that the beneficial effects of omega-3 fatty acid supplementation may depend on the stage of disease, other dietary mediators, and apolipoprotein E status.
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Affiliation(s)
- Gregory A Jicha
- University of Kentucky, Alzheimer's Disease Center and the Sanders-Brown Center on Aging University of Kentucky College of Medicine, Lexington, KY 40536-0230, USA.
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61
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Romanini CV, Schiavon AP, Ferreira EDF, de Oliveira RMW, Milani H. Sildenafil prevents mortality and reduces hippocampal damage after permanent, stepwise, 4-vessel occlusion in rats. Brain Res Bull 2010; 81:631-40. [DOI: 10.1016/j.brainresbull.2009.12.012] [Citation(s) in RCA: 10] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/18/2009] [Accepted: 12/22/2009] [Indexed: 11/30/2022]
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62
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Rostagno A, Holton JL, Lashley T, Revesz T, Ghiso J. Cerebral amyloidosis: amyloid subunits, mutants and phenotypes. Cell Mol Life Sci 2010; 67:581-600. [PMID: 19898742 PMCID: PMC3410709 DOI: 10.1007/s00018-009-0182-4] [Citation(s) in RCA: 43] [Impact Index Per Article: 3.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2009] [Accepted: 10/12/2009] [Indexed: 10/20/2022]
Abstract
Cerebral amyloid diseases are part of a complex group of chronic and progressive entities bracketed together under the common denomination of protein folding disorders and characterized by the intra- and extracellular accumulation of fibrillar aggregates. Of the more than 25 unrelated proteins known to produce amyloidosis in humans only about a third of them are associated with cerebral deposits translating in cognitive deficits, dementia, stroke, cerebellar and extrapyramidal signs, or a combination thereof. The familial forms reviewed herein, although infrequent, provide unique paradigms to examine the role of amyloid in the mechanism of disease pathogenesis and to dissect the link between vascular and parenchymal amyloid deposition and their differential contribution to neurodegeneration.
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Affiliation(s)
- A Rostagno
- Department of Pathology, New York University School of Medicine, New York, NY 10016, USA.
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63
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Abstract
Diabetes is not only an independent risk factor for lacunar infarction, especially in patients with multiple lacunar infarcts, but the presence of diabetes is also associated with worse functional recovery in these patients.
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64
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Aliev G, Palacios HH, Walrafen B, Lipsitt AE, Obrenovich ME, Morales L. Brain mitochondria as a primary target in the development of treatment strategies for Alzheimer disease. Int J Biochem Cell Biol 2009; 41:1989-2004. [DOI: 10.1016/j.biocel.2009.03.015] [Citation(s) in RCA: 75] [Impact Index Per Article: 5.0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/16/2008] [Revised: 03/29/2009] [Accepted: 03/30/2009] [Indexed: 12/01/2022]
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65
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McCarty MF, Barroso-Aranda J, Contreras F. Potential complementarity of high-flavanol cocoa powder and spirulina for health protection. Med Hypotheses 2009; 74:370-3. [PMID: 19577379 DOI: 10.1016/j.mehy.2008.09.060] [Citation(s) in RCA: 12] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2008] [Revised: 09/12/2008] [Accepted: 09/27/2008] [Indexed: 12/22/2022]
Abstract
Recent studies show that ingestion of flavanol-rich cocoa powder provokes increased endothelial production of nitric oxide - an effect likely mediated by epicatchin - and thus may have considerable potential for promoting vascular health. The Kuna Indians of Panama, who regularly consume large amounts of flavanol-rich cocoa, are virtually free of hypertension and stroke, even though they salt their food. Of potentially complementary merit is the cyanobacterium spirulina, which has been used as a food in certain cultures. Spirulina is exceptionally rich in phycocyanobilin (PCB), which recently has been shown to act as a potent inhibitor of NADPH oxidase; this effect likely rationalizes the broad range of anti-inflammatory, cytoprotective, and anti-atherosclerotic effects which orally administered spirulina has achieved in rodent studies. In light of the central pathogenic role which NADPH oxidase-derived oxidant stress plays in a vast range of disorders, spirulina or PCB-enriched spirulina extracts may have remarkable potential for preserving and restoring health. Joint administration of flavanol-rich cocoa powder and spirulina may have particular merit, inasmuch as cocoa can mask the somewhat disagreeable flavor and odor of spirulina, whereas the antioxidant impact of spirulina could be expected to amplify the bioactivity of the nitric oxide evoked by cocoa flavanols in inflamed endothelium. Moreover, there is reason to suspect that, by optimizing cerebrovascular perfusion while quelling cerebral oxidant stress, cocoa powder and spirulina could collaborate in prevention of senile dementia. Thus, food products featuring ample amounts of both high-flavanol cocoa powder and spirulina may have considerable potential for health promotion, and merit evaluation in rodent studies and clinical trials.
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66
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Bekard IB, Dunstan DE. Shear-Induced Deformation of Bovine Insulin in Couette Flow. J Phys Chem B 2009; 113:8453-7. [DOI: 10.1021/jp903522e] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Affiliation(s)
- Innocent B. Bekard
- Department of Chemical and Biomolecular Engineering, The University of Melbourne, Melbourne, Victoria 3010, Australia
| | - Dave E. Dunstan
- Department of Chemical and Biomolecular Engineering, The University of Melbourne, Melbourne, Victoria 3010, Australia
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67
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Stefani A, Sancesario G, Pierantozzi M, Leone G, Galati S, Hainsworth AH, Diomedi M. CSF biomarkers, impairment of cerebral hemodynamics and degree of cognitive decline in Alzheimer's and mixed dementia. J Neurol Sci 2009; 283:109-15. [PMID: 19278690 DOI: 10.1016/j.jns.2009.02.343] [Citation(s) in RCA: 57] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/27/2022]
Abstract
The in vivo diagnosis of Alzheimer's disease (AD) may be facilitated by cerebro-spinal fluid (CSF) biomarkers in combination with imaging and clinical assessments. By determining the concentration of beta amyloid fragments, total tau (t-tau) and phospho-tau (p-tau), it is possible to detect the conversion of mild cognitive impairment (MCI) to AD or distinguish AD vs. pseudo-dementia. However, these markers are poorly sensitive to the progressive disease stages. And far from clear is their role in "mixed" forms of dementia, as far as hemodynamic deficits complicate the clinical history. We have studied cerebral hemodynamic impairment in AD patients, relative to control subjects. Mean flow velocity (MFV), pulsatility index (PI) and cerebrovascular reactivity (assayed as breath-holding index, BHI) were evaluated by bilateral transcranial Doppler (TCD) monitoring of middle cerebral arteries. MFV and BHI were significantly lower and PI was significantly higher in AD patients with respect to control subjects. The presence of white-matter changes (WMC) in the AD cases did not influence any of the hemodynamic variables. Noticeably, MMSE score was correlated to BHI reduction (P<0.005). Our results, consistent with the recent literature indicate that hemodynamic impairment is a critical marker of cognitive decline and supports once more the hypothesis of a significant pathigenic role of vascular damage in AD. Similar functional alterations might be early hallmarks in a variety of dementia subtypes, including "mixed" dementia, whose prevalence is undoubtedly increased. Assessment of hemodynamic reactivity could provide valuable correlations with individual patient's cognitive profile, which in turn would assist in the identification of critical steps in disease progression and the validation of effective therapies.
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Affiliation(s)
- Alessandro Stefani
- Department of Neuroscience, University of Rome Tor Vergata, Rome, Italy.
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68
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Cerebrovascular and cardiovascular pathology in Alzheimer's disease. INTERNATIONAL REVIEW OF NEUROBIOLOGY 2009; 84:35-48. [PMID: 19501712 DOI: 10.1016/s0074-7742(09)00403-6] [Citation(s) in RCA: 63] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 01/22/2023]
Abstract
Presently, compelling evidence indicates that Alzheimer's disease (AD) is a vascular disorder with neurodegenerative consequences and should be treated as such. A substantial body of evidence including epidemiological, pharmacotherapeutic, and neuroimaging studies support the concept of AD as a vascular disorder or vasocognopathy that initiates as brain hypoperfusion, creating a neuronal energy crisis. The neuronal energy crisis provokes the cellular and molecular changes that characterize this dementia. In this brief review, the many vascular-related risk factors to AD including some that are preventable or amenable to treatment are discussed. Considerable human data now point in a new direction for guiding future research into AD. This new research direction should open a window of opportunity for decisive management and treatment of this devastating disorder.
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69
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Gong CX, Iqbal K. Hyperphosphorylation of microtubule-associated protein tau: a promising therapeutic target for Alzheimer disease. Curr Med Chem 2008; 15:2321-8. [PMID: 18855662 DOI: 10.2174/092986708785909111] [Citation(s) in RCA: 380] [Impact Index Per Article: 23.8] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/10/2023]
Abstract
Alzheimer disease (AD) is the most common cause of dementia in adults. The current therapy for AD has only moderate efficacy in controlling symptoms, and it does not cure the disease. Recent studies have suggested that abnormal hyperphosphorylation of tau in the brain plays a vital role in the molecular pathogenesis of AD and in neurodegeneration. This article reviews the current advances in understanding of tau protein, regulation of tau phosphorylation, and the role of its abnormal hyperphosphorylation in neurofibrillary degeneration. Furthermore, several therapeutic strategies for treating AD on the basis of the important role of tau hyperphosphorylation in the pathogenesis of the disease are described. These strategies include (1) inhibition of glycogen synthase kinase-3beta (GSK-3beta), cyclin-dependent kinase 5 (cdk5), and other tau kinases; (2) restoration of PP2A activity; and (3) targeting tau O-GlcNAcylation. Development of drugs on the basis of these strategies is likely to lead to disease-modifying therapies for AD.
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Affiliation(s)
- C-X Gong
- Department of Neurochemistry, New York State Institute for Basic Research in Developmental Disabilities, Staten Island, New York, USA.
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70
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The cognitive and histopathological effects of chronic 4-vessel occlusion in rats depend on the set of vessels occluded and the age of the animals. Behav Brain Res 2008; 197:378-87. [PMID: 19007820 DOI: 10.1016/j.bbr.2008.10.023] [Citation(s) in RCA: 18] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/09/2008] [Revised: 09/26/2008] [Accepted: 10/02/2008] [Indexed: 11/24/2022]
Abstract
Continuing previous efforts to develop the 4-vessel occlusion (4-VO) model of chronic cerebral hypoperfusion (CCH), here we evaluated whether permanent, stepwise 4-VO causes both learning deficits, hippocampal neurodegeneration and retinal lesion in young, middle-aged or aged rats. Chronic 4-VO was induced by ligation of different sets of vessels, i.e., the vertebral arteries (VA) plus common carotid arteries (CCA) (4-VO/CCA model) or the VA plus internal carotid arteries (ICA) (4-VO/ICA model) with a 1-week interstage interval. Forty days after the 4-VO, the rats were tested for spatial learning impairment, and then examined for hypoxic/ischemic damage. Young, 4-VO/CCA rats exhibited cognitive impairment, hippocampal neurodegeneration and retinal lesion (p<0.0001-0.05). After 4-VO/ICA, neither young nor middle-aged rats exhibited any learning deficits, hippocampal or retinal damage. In aged rats, chronic 4-VO/ICA caused a mild learning deficit (p<0.05). A significant effect of training was observed for the old, sham-operated rats (p<0.0001-0.001), but not for the aged 4-VO/ICA rats (p>0.05). On average, hippocampal cell density did not change after 4-VO/ICA in aged rats, but 3 of 10 subjects exhibited reduced pyramidal cell counts in all hippocampal subfields. Retinal morphology appeared to be unaffected in the 4-VO/ICA aged rats. These data suggest that the 4-VO/ICA model, but not the 4-VO/CCA model, is a suitable paradigm to study the behavioral outcome of CCH given the preservation of the retina after 4-VO/ICA. Moreover, the age at which 4-VO/ICA occurs seems to be an important factor for determining the behavioral and neuropathological changes.
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Hamilton-Brown P, Bekard I, Ducker WA, Dunstan DE. How Does Shear Affect Aβ Fibrillogenesis? J Phys Chem B 2008; 112:16249-52. [DOI: 10.1021/jp805257n] [Citation(s) in RCA: 41] [Impact Index Per Article: 2.6] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/31/2022]
Affiliation(s)
- Paul Hamilton-Brown
- Department of Chemical and Biomolecular Engineering and Particulate Fluids Processing Centre, University of Melbourne, Victoria 3010, Australia
| | - Innocent Bekard
- Department of Chemical and Biomolecular Engineering and Particulate Fluids Processing Centre, University of Melbourne, Victoria 3010, Australia
| | - William A. Ducker
- Department of Chemical and Biomolecular Engineering and Particulate Fluids Processing Centre, University of Melbourne, Victoria 3010, Australia
| | - Dave E. Dunstan
- Department of Chemical and Biomolecular Engineering and Particulate Fluids Processing Centre, University of Melbourne, Victoria 3010, Australia
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72
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What initiates the formation of senile plaques? The origin of Alzheimer-like dementias in capillary haemorrhages. Med Hypotheses 2008; 71:347-59. [DOI: 10.1016/j.mehy.2008.04.007] [Citation(s) in RCA: 39] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/24/2008] [Revised: 03/24/2008] [Accepted: 04/03/2008] [Indexed: 01/18/2023]
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73
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Clifford PM, Siu G, Kosciuk M, Levin EC, Venkataraman V, D'Andrea MR, Nagele RG. Alpha7 nicotinic acetylcholine receptor expression by vascular smooth muscle cells facilitates the deposition of Abeta peptides and promotes cerebrovascular amyloid angiopathy. Brain Res 2008; 1234:158-71. [PMID: 18708033 DOI: 10.1016/j.brainres.2008.07.092] [Citation(s) in RCA: 31] [Impact Index Per Article: 1.9] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/02/2008] [Revised: 07/14/2008] [Accepted: 07/16/2008] [Indexed: 01/21/2023]
Abstract
Deposition of beta-amyloid (Abeta) peptides in the walls of brain blood vessels, cerebral amyloid angiopathy (CAA), is common in patients with Alzheimer's disease (AD). Previous studies have demonstrated Abeta peptide deposition among vascular smooth muscle cells (VSMCs), but the source of the Abeta and basis for its selective deposition in VSMCs are unknown. In the present study, we examined the deposition patterns of Abeta peptides, Abeta40 and Abeta42, within the cerebrovasculature of AD and control patients using single- and double-label immunohistochemistry. Abeta40 and Abeta42 were abundant in VSMCs, especially in leptomeningeal arteries and their initial cortical branches; in later-stage AD brains this pattern extended into the microvasculature. Abeta peptide deposition was linked to loss of VSMC viability. Perivascular leak clouds of Abeta-positive material were associated primarily with arterioles. By contrast, control brains possessed far fewer Abeta42- and Abeta40-immunopositive blood vessels, with perivascular leak clouds of Abeta-immunopositive material rarely observed. We also demonstrate that VSMCs in brain blood vessels express the alpha7 nicotinic acetylcholine receptor (alpha7nAChR), which has high binding affinity for Abeta peptides, especially Abeta42. These results suggest that the blood and blood-brain barrier permeability provide a major source of the Abeta peptides that gradually deposit in brain VSMCs, and the presence and abundance of the alpha7nAChR on VSMCs may facilitate the selective accumulation of Abeta peptides in these cells.
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Affiliation(s)
- Peter M Clifford
- University of Medicine and Dentistry of New Jersey/Graduate School of Biomedical Sciences, 2 Medical Center Drive, Stratford, NJ 08084, USA
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74
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Kumaran D, Udayabanu M, Kumar M, Aneja R, Katyal A. Involvement of angiotensin converting enzyme in cerebral hypoperfusion induced anterograde memory impairment and cholinergic dysfunction in rats. Neuroscience 2008; 155:626-39. [DOI: 10.1016/j.neuroscience.2008.06.023] [Citation(s) in RCA: 59] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/28/2008] [Revised: 06/03/2008] [Accepted: 06/04/2008] [Indexed: 10/21/2022]
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75
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Jicha GA, Parisi JE, Dickson DW, Cha RH, Johnson KA, Smith GE, Boeve BF, Petersen RC, Knopman DS. Age and apoE associations with complex pathologic features in Alzheimer's disease. J Neurol Sci 2008; 273:34-9. [PMID: 18653200 DOI: 10.1016/j.jns.2008.06.008] [Citation(s) in RCA: 21] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/27/2008] [Revised: 06/06/2008] [Accepted: 06/09/2008] [Indexed: 11/30/2022]
Abstract
The risk for Alzheimer's disease (AD) is influenced by both age and ApoE status. The present study addresses the associations of age and ApoE status on complex pathologic features in AD (n=81) including coexistent cerebrovascular disease (CVD), argyrophilic grain disease (AGD), and Lewy body disease (LBD). The frequency of coexistent cerebrovascular disease increased with increasing age. Age and ApoE status were differentially associated with atherosclerosis, lacunar infarctions, and microvascular pathology. Coexistent Lewy body pathology was negatively associated with age, dropping off abruptly after age 90. The presence of an ApoE epsilon4 allele was associated with an increased frequency of coexistent LBD. Logistic regression analyses demonstrated both dependent and independent effects of age and ApoE status on the presence of coexistent Lewy body pathology in AD. While the decreasing frequency of LBD in AD after age 90 could be partly accounted for by a lower probability of an ApoE epsilon4 allele, the independent association with age suggests either 1) a survival effect, 2) decreased incidence with advancing age, or 3) both.
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Affiliation(s)
- Gregory A Jicha
- Department of Neurology, Mayo Clinic, Rochester, MN, Jacksonville, FL, United States
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76
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Patterns of neuropsychological impairment in MCI patients with small subcortical infarcts or hippocampal atrophy. J Int Neuropsychol Soc 2008; 14:611-9. [PMID: 18577290 DOI: 10.1017/s1355617708080831] [Citation(s) in RCA: 25] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/05/2022]
Abstract
We investigated whether MCI patients with hippocampal atrophy or multiple subcortical infarcts demonstrate neuropsychological patterns and markers considered typical of Alzheimer's disease (AD) and of vascular dementia (VD), respectively. An extensive neuropsychological battery, including tests of memory, visual-spatial and executive functions, language, attention, praxis and psychomotor speed, was administered to 36 mild cognitive impairment (MCI) patients with hippocampal atrophy and 41 MCI patients with multiple subcortical infarcts. Both groups of MCI patients were very mildly impaired and well matched in terms of MMSE scores. A clear, disproportionately severe, episodic memory disorder was observed in MCI patients with hippocampal atrophy. A less specific neuropsychological profile, consisting of impairment on an Action Naming task that is sensitive to frontal lobe lesions, was observed in MCI patients with multiple subcortical infarcts. In MCI patients, a disproportionately severe episodic memory impairment strongly points to an Alzheimer's type brain pathology, whereas the prevalence of executive deficits and other frontal lobe symptoms are a much weaker diagnostic marker of small vessel subcortical disease.
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77
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de la Torre JC. Pathophysiology of neuronal energy crisis in Alzheimer's disease. NEURODEGENER DIS 2008; 5:126-32. [PMID: 18322369 DOI: 10.1159/000113681] [Citation(s) in RCA: 92] [Impact Index Per Article: 5.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
Abstract
A large body of evidence indicates that sporadic Alzheimer's disease (AD) is a vascular disorder with neurodegenerative consequences and needs to be treated and managed as such. Epidemiologic studies of vascular risk factors, together with preclinical detection tools for AD are proof of concept that cerebral hypoperfusion is one of the earliest pathological signs in the development of cognitive failure. Vascular risk factors involving heart disease and stroke in the elderly individual who already possesses a dwindling cerebrovascular reserve due to advancing age contribute to further decline in cerebral blood flow (CBF) resulting in unrelenting brain hypoperfusion. Brain hypoperfusion, in turn, can reach a critically attained threshold of cerebral hypoperfusion (CATCH) giving rise to a neuronal energy crisis via reduced ATP synthesis. The ensuing metabolic energy crisis initially carves up ischemic-sensitive neurons in the hippocampus and posterior parietal cortex setting up cognitive meltdown and progressive neurodegenerative and atrophic changes in the brain. Neuronal energy compromise accelerates oxidative stress, excess production of reactive oxygen species, aberrant protein synthesis, ionic membrane pump dysfunction, signal transduction impairment, neurotransmitter failure, abnormal processing of amyloid precursor protein resulting in beta-amyloid deposition and axonal microtubule disruption from tau hyperphosphorylation. The high energy metabolic changes leading to oxidative stress and cellular hypometabolism precede clinical expression of AD. Regional CBF measurements using neuroimaging techniques can predict AD preclinically at the mild cognitive impairment stage or even before any clinical manifestation of dementia is expressed. Clinical diagnostic assessment of elderly persons who could develop or already present with memory complaints can prevent, reverse or slow down AD development. Although pathologic aging is the subject of thousands of studies, the question of why the elderly (and not younger people) succumb to AD has not been adequately addressed. The explanation(s) as to why vascular risk factors, for example, can trigger AD or vascular dementia usually in the elderly and not the young should provide vital clues in the search for a strategically effective dementia treatment. This review offers inductive hypothetical darts relative to that critical question.
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Affiliation(s)
- Jack C de la Torre
- Institute of Pathology, Case Western Reserve School of Medicine, Cleveland, Ohio, USA.
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78
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Zacchigna S, Lambrechts D, Carmeliet P. Neurovascular signalling defects in neurodegeneration. Nat Rev Neurosci 2008; 9:169-81. [DOI: 10.1038/nrn2336] [Citation(s) in RCA: 275] [Impact Index Per Article: 17.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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79
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Erkinjuntti T. Vascular Cognitive Deterioration and Stroke. Cerebrovasc Dis 2007; 24 Suppl 1:189-94. [DOI: 10.1159/000107395] [Citation(s) in RCA: 37] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/19/2022] Open
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80
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Omental transposition in treatment of Alzheimer disease. J Am Coll Surg 2007; 205:800-4. [PMID: 18035264 DOI: 10.1016/j.jamcollsurg.2007.06.294] [Citation(s) in RCA: 16] [Impact Index Per Article: 0.9] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/01/2007] [Revised: 06/11/2007] [Accepted: 06/14/2007] [Indexed: 11/22/2022]
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81
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Antoine V, Souid M, Bodenan L. La population âgée hémodialysée : évaluer et prendre en charge le risque de déclin cognitif. Nephrol Ther 2007; 3:11-26. [PMID: 17383587 DOI: 10.1016/j.nephro.2006.11.005] [Citation(s) in RCA: 3] [Impact Index Per Article: 0.2] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/12/2005] [Revised: 04/14/2006] [Accepted: 11/14/2006] [Indexed: 12/25/2022]
Abstract
Epidemiological data suggest a large prevalence of cognitive impairment in elderly patients on haemodialysis. They are frequently exposed to pathologies that affect the brain, and hold a plurality of risk factors for neurodegenerative and vascular dementia. Cognitive dysfunctions, because of their medical and socio-economical consequences, may led to discuss the indication for haemodialysis and its profit for the elderly patient. These facts highlight the advantage of a regular assessment of cognitive functions in this population. They also suggest the need in the future of a multidisciplinary intervention for these patients, for a better evaluation of interventions aimed on primary and secondary prevention of cognitive decline in the elderly group.
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Affiliation(s)
- Valéry Antoine
- Consultation de la mémoire, unité mobile de gériatrie, hôpital de Poissy, CHI de Poissy-Saint-Germain-en-Laye, Les Maisonnées, Poissy, France.
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82
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Arra M, Emanuele E, Martinelli V, Minoretti P, Bertona M, Geroldi D. The M694V variant of the familial Mediterranean fever gene is associated with sporadic early-onset Alzheimer's disease in an Italian population sample. Dement Geriatr Cogn Disord 2007; 23:55-9. [PMID: 17090974 DOI: 10.1159/000096743] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Accepted: 09/06/2006] [Indexed: 11/19/2022] Open
Abstract
BACKGROUND Inflammation is deemed to play a crucial role in the pathogenesis of Alzheimer's disease (AD). We sought to determine whether the proinflammatory M694V mutation of pyrin, the gene responsible for familial Mediterranean fever, could lead to an increased risk for AD. METHODS We compared the M694V variant genotypes in 378 sporadic AD patients and 384 healthy control subjects of Italian descent. RESULTS After adjustment for potential confounders, the M694V mutation was found to be associated with an increased risk for AD in subjects with an age at onset of 65 years or younger (multivariate-adjusted odds ratio, OR: 3.01, 95% confidence interval, CI: 1.24-6.72, p = 0.021), but not in patients with an age at onset older than 65 years (multivariate-adjusted OR: 0.81, 95% CI: 0.34-1.99, p = 0.847). Kaplan-Meier analysis indicated that AD patients bearing the M694V mutation presented with disease onset 7 years earlier than carriers of the wild-type genotype (log rank = 41.61, p < 0.001). CONCLUSION Our data indicate that the M694V sequence variant in the pyrin gene might influence the age at onset of AD in the Italian population.
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Affiliation(s)
- Mariarosa Arra
- Interdepartmental Center for Research in Molecular Medicine, University of Pavia, Pavia, Italy
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83
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Clifford PM, Zarrabi S, Siu G, Kinsler KJ, Kosciuk MC, Venkataraman V, D'Andrea MR, Dinsmore S, Nagele RG. Abeta peptides can enter the brain through a defective blood-brain barrier and bind selectively to neurons. Brain Res 2007; 1142:223-36. [PMID: 17306234 DOI: 10.1016/j.brainres.2007.01.070] [Citation(s) in RCA: 100] [Impact Index Per Article: 5.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/02/2006] [Revised: 01/11/2007] [Accepted: 01/11/2007] [Indexed: 11/28/2022]
Abstract
We have investigated the possibility that soluble, blood-borne amyloid beta (Abeta) peptides can cross a defective blood-brain barrier (BBB) and interact with neurons in the brain. Immunohistochemical analyses revealed extravasated plasma components, including Abeta42 in 19 of 21 AD brains, but in only 3 of 13 age-matched control brains, suggesting that a defective BBB is common in AD. To more directly test whether blood-borne Abeta peptides can cross a defective BBB, we tracked the fate of fluorescein isothiocyanate (FITC)-labeled Abeta42 and Abeta40 introduced via tail vein injection into mice with a BBB rendered permeable by treatment with pertussis toxin. Both Abeta40 and Abeta42 readily crossed the permeabilized BBB and bound selectively to certain neuronal subtypes, but not glial cells. By 48 h post-injection, Abeta42-positive neurons were widespread in the brain. In the cerebral cortex, small fluorescent, Abeta42-positive granules were found in the perinuclear cytoplasm of pyramidal neurons, suggesting that these cells can internalize exogenous Abeta42. An intact BBB (saline-injected controls) blocked entry of blood-borne Abeta peptides into the brain. The neuronal subtype selectivity of Abeta42 and Abeta40 was most evident in mouse brains subjected to direct intracranial stereotaxic injection into the hippocampal region, thereby bypassing the BBB. Abeta40 was found to preferentially bind to a distinct subset of neurons positioned at the inner face of the dentate gyrus, whereas Abeta42 bound selectively to the population of large neurons in the hilus region of the dentate gyrus. Our results suggest that the blood may serve as a major, chronic source of soluble, exogenous Abeta peptides that can bind selectively to certain subtypes of neurons and accumulate within these cells.
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Affiliation(s)
- Peter M Clifford
- New Jersey Institute for Successful Aging, University of Medicine and Dentistry of New Jersey/SOM, 2 Medical Center Drive, Stratford, NJ 08084, USA
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84
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Jellinger KA. The enigma of mixed dementia. Alzheimers Dement 2007; 3:40-53. [DOI: 10.1016/j.jalz.2006.09.002] [Citation(s) in RCA: 74] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2006] [Accepted: 09/22/2006] [Indexed: 10/23/2022]
Affiliation(s)
- Kurt A. Jellinger
- Institute of Clinical Neurobiology; Kenyongasse 18, A-1070 Vienna Austria
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85
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Roher AE, Garami Z, Alexandrov AV, Kokjohn TA, Esh CL, Kalback WM, Vedders LJ, Wilson JR, Sabbagh MN, Beach TG. Interaction of cardiovascular disease and neurodegeneration: transcranial Doppler ultrasonography and Alzheimer's disease. Neurol Res 2006; 28:672-8. [PMID: 16945221 DOI: 10.1179/016164106x130470] [Citation(s) in RCA: 43] [Impact Index Per Article: 2.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/31/2022]
Abstract
OBJECTIVE Recent post-mortem studies have reported that the severity of atheromatous deposits in the circle of Willis is significantly greater, relative to non-demented (ND) elderly persons, in subjects with neuropathologically diagnosed Alzheimer's disease (AD). Additionally, the severity of intracranial atherosclerosis correlates significantly with the densities of neuritic plaques and neurofibrillary tangles. In this study, we examine the arteries of the circle of Willis by transcranial Doppler (TCD) ultrasonography. METHODS TCD was used to measure, in 25 AD patients and 30 ND elderly subjects, mean flow velocities and pulsatility indices in 16 different segments of the circle of Willis. The data were compared with and without adjustment for age, gender and systolic blood pressure. RESULTS The AD patients had systematically higher pulsatility indices (p<0.005) than the ND group. Incremental increases of pulsatility indices in these segments had odds ratios ranging from 1.8 to 48 for the presence of AD when adjusted for age, gender and systolic blood pressure. The left internal carotid artery siphon and the left posterior cerebral artery were the two vessels that were strongly associated with AD diagnosis. Mean flow velocities were generally lower in patients with AD but the differences did not reach the significance level. DISCUSSION The pulsatility indices of the arteries of AD patients were generally greater than those of similarly-aged ND subjects. This difference is most likely due to increased arterial wall rigidity imposed by atherosclerotic changes. Atherosclerotic disease of intracranial arteries may be a risk factor for AD.
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Affiliation(s)
- Alex E Roher
- Longtine Center for Molecular Biology and Genetics, Sun Health Research Institute, Sun City AZ 85351, USA.
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86
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Fischer C, Schneider M, Carmeliet P. Principles and therapeutic implications of angiogenesis, vasculogenesis and arteriogenesis. Handb Exp Pharmacol 2006:157-212. [PMID: 16999228 DOI: 10.1007/3-540-36028-x_6] [Citation(s) in RCA: 67] [Impact Index Per Article: 3.7] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/20/2022]
Abstract
The vasculature is the first organ to arise during development. Blood vessels run through virtually every organ in the body (except the avascular cornea and the cartilage), assuring metabolic homeostasis by supplying oxygen and nutrients and removing waste products. Not surprisingly therefore, vessels are critical for organ growth in the embryo and for repair of wounded tissue in the adult. Notably, however, an imbalance in angiogenesis (the growth of blood vessels) contributes to the pathogenesis of numerous malignant, inflammatory, ischaemic, infectious and immune disorders. During the last two decades, an explosive interest in angiogenesis research has generated the necessary insights to develop the first clinically approved anti-angiogenic agents for cancer and blindness. This novel treatment is likely to change the face of medicine in the next decade, as over 500 million people worldwide are estimated to benefit from pro- or anti-angiogenesis treatment. In this following chapter, we discuss general key angiogenic mechanisms in health and disease, and highlight recent developments and perspectives of anti-angiogenic therapeutic strategies.
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Affiliation(s)
- C Fischer
- Centre for Transgene Technology and Gene Therapy, Flanders Interuniversity Institute for Biotechnology, KULeuven, Campus Gasthuisberg, Herestraat 49, 3000 Leuven, Belgium
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87
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Affiliation(s)
- Christopher M Ryan
- University of Pittsburgh School of Medicine, 3811 O'Hara Street, Pittsburgh, PA, 15213, USA.
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88
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Arshavsky YI. “The seven sins” of the Hebbian synapse: Can the hypothesis of synaptic plasticity explain long-term memory consolidation? Prog Neurobiol 2006; 80:99-113. [PMID: 17074430 DOI: 10.1016/j.pneurobio.2006.09.004] [Citation(s) in RCA: 50] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/28/2006] [Revised: 09/25/2006] [Accepted: 09/26/2006] [Indexed: 11/16/2022]
Abstract
Memorizing new facts and events means that entering information produces specific physical changes within the brain. According to the commonly accepted view, traces of memory are stored through the structural modifications of synaptic connections, which result in changes of synaptic efficiency and, therefore, in formations of new patterns of neural activity (the hypothesis of synaptic plasticity). Most of the current knowledge on learning and initial stages of memory consolidation ("synaptic consolidation") is based on this hypothesis. However, the hypothesis of synaptic plasticity faces a number of conceptual and experimental difficulties when it deals with potentially permanent consolidation of declarative memory ("system consolidation"). These difficulties are rooted in the major intrinsic self-contradiction of the hypothesis: stable declarative memory is unlikely to be based on such a non-stable foundation as synaptic plasticity. Memory that can last throughout an entire lifespan should be "etched in stone." The only "stone-like" molecules within living cells are DNA molecules. Therefore, I advocate an alternative, genomic hypothesis of memory, which suggests that acquired information is persistently stored within individual neurons through modifications of DNA, and that these modifications serve as the carriers of elementary memory traces.
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Affiliation(s)
- Yuri I Arshavsky
- Institute for Nonlinear Science, University of California San Diego, La Jolla, CA 92093-0402, USA.
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89
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Selley ML. A metabolic link between S-adenosylhomocysteine and polyunsaturated fatty acid metabolism in Alzheimer's disease. Neurobiol Aging 2006; 28:1834-9. [PMID: 16996649 DOI: 10.1016/j.neurobiolaging.2006.08.003] [Citation(s) in RCA: 89] [Impact Index Per Article: 4.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/03/2005] [Revised: 07/07/2006] [Accepted: 08/15/2006] [Indexed: 01/20/2023]
Abstract
There is evidence that vascular risk factors contribute to the pathology of Alzheimer's disease. Increased concentrations of circulating homocysteine are associated with vascular risk factors and Alzheimer's disease but the mechanisms involved are unclear. Homocysteine inhibits the hydrolysis of S-adenosylhomocysteine (SAH) which is a product inhibitor of S-adenosylmethionine (SAM) dependent methyltransferase reactions. It has been shown previously that SAH inhibits phosphatidylethanolamine N-methyltransferase (PEMT) in the liver. The activity of PEMT in the liver plays an important role in the methylation of phosphatidylethanolamine (PE) to phosphatidylcholine (PC) and the delivery of essential polyunsaturated fatty acids (PUFAs) to peripheral tissues. In the present study, the plasma concentrations of SAH, SAM and homocysteine and the erythrocyte composition of phosphatidylcholine (PC), phosphatidylethanolamine (PE) and their respective polyunsaturated fatty acid concentrations were determined in 26 patients with Alzheimer's disease and compared to those in 29 healthy control subjects. There was a significant increase in the plasma concentrations of SAH (p<0.001) and homocysteine (p<0.001) and a significant increase in the plasma concentrations of SAM (p<0.001) in the Alzheimer's patients. A significant positive correlation was found between the plasma concentrations of SAH and homocysteine (r=0.738, p<0.001). There was a negative correlation between the plasma concentrations of homocysteine and the ratio of SAM/SAH (r=-0.637, p<0.01). There was a significant decrease in the erythrocyte content of PC (p<0.001) and an increase in the erythrocyte content of PE (p<0.001) in the Alzheimer's patients. Plasma SAH concentrations were negatively related to erythrocyte PC concentrations (r=-0.286, p<0.01) and positively related to erythrocyte PE concentrations (r=0.429, p<0.001). The erythrocyte PC from Alzheimer's patients had a significant depletion of docosahexaenoic acid (DHA) (p<0.001) while there was no significant difference in the DHA content of erythrocyte PE. There was a significant negative correlation between plasma SAH and the DHA composition of erythrocyte PC (r=-0.271, p<0.001). This data may reflect the inhibition of hepatic PEMT activity by SAH in Alzheimer's disease. The decreased mobilization of DHA from the liver into plasma and peripheral tissues may increases the risk of atherosclerosis and stroke leading to chronic cerebral hypoperfusion. The evidence suggests that a metabolic link between the increased production of SAH and phospholipid metabolism may contribute to cerebrovascular and neurodegenerative changes in Alzheimer's disease.
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Affiliation(s)
- Michael L Selley
- Angiogen Pharmaceuticals Pty. Ltd., Level 31, ABN AMRO Tower, 88 Phillip Street, Sydney, NSW 2000, Australia.
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90
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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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91
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Chapuis J, Tian J, Shi J, Bensemain F, Cottel D, Lendon C, Amouyel P, Mann D, Lambert JC. Association study of the vascular endothelial growth factor gene with the risk of developing Alzheimer's disease. Neurobiol Aging 2006; 27:1212-5. [PMID: 16154235 DOI: 10.1016/j.neurobiolaging.2005.07.013] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 05/30/2005] [Revised: 07/19/2005] [Accepted: 07/20/2005] [Indexed: 11/15/2022]
Abstract
Numerous observations indicate that cerebrovascular dysfunction contributes to cognitive decline and neurodegeneration in AD. Converging evidence points to a pivotal role for vascular endothelial growth factor (VEGF) in neuronal protection, and the lack of activity of this in neurodegenerative disorders. The VEGF gene is located at 6p21.3, a site several studies have shown to have significant linkage with AD, and a functional polymorphism within the VEGF promoter may alter the risk of developing AD. We assessed the potential impact of this polymorphism on the risk of developing AD in a large French case-control population, and investigated its association with the severity of brain vascular lesions (arteriosclerosis, white matter loss and cerebral amyloid angiopathy) in several brain regions (frontal, temporal, parietal and occipital cortex) in AD. No association of the VEGF promoter polymorphism with the risk of developing AD was observed. No relationship between this polymorphism and vascular pathological changes in AD was detected. Our data indicate that although this polymorphism is functional, it does not confer greater risk for AD, nor modulate the extent of vascular pathology.
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Affiliation(s)
- Julien Chapuis
- Unité INSERM 508, Institut Pasteur de Lille, 1 rue du Professeur Calmette, BP 245, 59019 Lille Cédex, France
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92
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Arshavsky YI. Alzheimer's disease, brain immune privilege and memory: a hypothesis. J Neural Transm (Vienna) 2006; 113:1697-707. [PMID: 16932992 DOI: 10.1007/s00702-006-0524-4] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/08/2006] [Accepted: 04/28/2006] [Indexed: 12/13/2022]
Abstract
The most distinctive feature of Alzheimer's disease (AD) is the specific degeneration of the neurons involved in memory consolidation, storage, and retrieval. Patients suffering from AD forget basic information about their past, loose linguistic and calculative abilities and communication skills. Thus, understanding the etiology of AD may provide insights into the mechanisms of memory and vice versa. The brain is an immunologically privileged site protected from the organism's immune reactions by the blood-brain barrier (BBB). All risk factors for AD (both cardiovascular and genetic) lead to destruction of the BBB. Evidence emerging from recent literature indicates that AD may have an autoimmune nature associated with BBB impairments. This hypothesis suggests that the process of memory consolidation involves the synthesis of novel macromolecules recognized by the immune system as "non-self" antigens. The objective of this paper is to stimulate new approaches to studies of neural mechanisms underpinning memory consolidation and its breakdown during AD. If the hypothesis on the autoimmune nature of AD is correct, the identification of the putative antigenic macromolecules might be critical to understanding the etiology and prevention of AD, as well as for elucidating cellular mechanisms of learning and memory.
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Affiliation(s)
- Y I Arshavsky
- Institute for Nonlinear Science, University of California San Diego, La Jolla, CA 92093-0402, USA.
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93
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Lynch JA, George AM, Eisenhauer PB, Conn K, Gao W, Carreras I, Wells JM, McKee A, Ullman MD, Fine RE. Insulin degrading enzyme is localized predominantly at the cell surface of polarized and unpolarized human cerebrovascular endothelial cell cultures. J Neurosci Res 2006; 83:1262-70. [PMID: 16511862 DOI: 10.1002/jnr.20809] [Citation(s) in RCA: 32] [Impact Index Per Article: 1.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/12/2022]
Abstract
Insulin degrading enzyme (IDE) is expressed in the brain and may play an important role there in the degradation of the amyloid beta peptide (Abeta). Our results show that cultured human cerebrovascular endothelial cells (HCECs), a primary component of the blood-brain barrier, express IDE and may respond to exposure to low levels of Abeta by upregulating its expression. When radiolabeled Abeta is introduced to the medium of cultured HCECs, it is rapidly degraded to smaller fragments. We believe that this degradation is largely the result of the action of IDE, as it can be substantially blocked by the presence of insulin in the medium, a competitive substrate of IDE. No inhibition is seen when an inhibitor of neprilysin, another protease that may degrade Abeta, is present in the medium. Our evidence suggests that the action of IDE occurs outside the cell, as inhibitors of internalization fail to affect the rate of the observed degradation. Further, our evidence suggests that degradation by IDE occurs on the plasma membrane, as much of the IDE present in HCECs was biotin-labeled by a plasma membrane impermeable reagent. This activity seems to be polarity dependent, as measurement of Abeta degradation by each surface of differentiated HCECs shows greater degradation on the basolateral (brain-facing) surface. Thus, IDE could be an important therapeutic target to decrease the amount of Abeta in the cerebrovasculature.
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Affiliation(s)
- John A Lynch
- Department of Biochemistry, Boston University School of Medicine, Boston, Massachusetts 02118, USA
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94
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Draper B, Brodaty H, Low LF. A tiered model of psychogeriatric service delivery: an evidence-based approach. Int J Geriatr Psychiatry 2006; 21:645-53. [PMID: 16802279 DOI: 10.1002/gps.1541] [Citation(s) in RCA: 15] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Indexed: 11/11/2022]
Abstract
BACKGROUND Previous models of mental health care for older persons have not considered the full spectrum of mental disorders. AIM To describe a tiered model for comprehensive evidence-based planning of service delivery for mental disorders in late life. METHOD The model depicts tiers of mental disorders in ascending order of severity and consequent interventions required. RESULTS Interventions aim both to avert individuals from moving up tiers (prevention) and to move individuals down tiers (treatment). Individuals in the lower tiers have no mental disorders and prevention strategies are targeted at known risk factors. In the middle tiers, individuals with mild-moderate mental disorders will mainly be treated in primary care, often in collaboration with specialist mental health services for older people. Individuals in the top tiers with severe mental disorders usually require institutional care. CONCLUSION The tiered model provides a basis for planning comprehensive service delivery.
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Affiliation(s)
- Brian Draper
- School of Psychiatry, University of NSW, Sydney, Australia.
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95
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Ohtaki H, Fujimoto T, Sato T, Kishimoto K, Fujimoto M, Moriya M, Shioda S. Progressive expression of vascular endothelial growth factor (VEGF) and angiogenesis after chronic ischemic hypoperfusion in rat. ACTA NEUROCHIRURGICA. SUPPLEMENT 2006; 96:283-7. [PMID: 16671472 DOI: 10.1007/3-211-30714-1_61] [Citation(s) in RCA: 29] [Impact Index Per Article: 1.6] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 03/16/2023]
Abstract
Cerebrovascular stenosis caused by arteriosclerosis induces failure of the cerebral circulation. Even if chronic cerebral hypoperfusion does not induce acute neuronal cell death, cerebral hypoperfusion may be a risk factor for neurodegenerative diseases. The purpose of this study was to determine if vasodilation, expression of VEGF, and neovascularization are homeostatic signs of cerebral circulation failure after permanent common carotid artery occlusion (CCAO) in the rat. Neuronal cell death in neocortex was observed 2 weeks after CCAO and gradually increased in a time-dependent manner. The diameter of capillaries and expression of VEGF also increased progressively after CCAO. Moreover, we observed unusual irregular angiogenic vasculature at 4 weeks. In conclusion, chronic hypoperfusion results in mechanisms to compensate for insufficiency in blood flow including vasodilation, VEGF expression, and neovascularization in the ischemic region. These results suggest that angiogenesis might be induced in adult brain through the support of growth factors and transplantation of vascular progenitor cells, and that neovascularization might be a therapeutic strategy for children and adults with diseases such as vascular dementia.
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Affiliation(s)
- H Ohtaki
- Department of Neurosurgery, Showa University, Fujigaoka Hospital, Kanagawa, Japan.
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96
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Guang HM, Du GH. Protections of pinocembrin on brain mitochondria contribute to cognitive improvement in chronic cerebral hypoperfused rats. Eur J Pharmacol 2006; 542:77-83. [PMID: 16806158 DOI: 10.1016/j.ejphar.2006.04.054] [Citation(s) in RCA: 54] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2006] [Revised: 04/04/2006] [Accepted: 04/06/2006] [Indexed: 10/24/2022]
Abstract
To study effects of pinocembrin, a natural compound extracted from propolis, on cognitive ability impaired by chronic cerebral hypoperfusion in rats, and if it did so, to investigate its effects on brain mitochondria. Rat chronic cerebral hypoperfusion was achieved by permanent bilateral common carotid arteries ligation, with regional cerebral blood flow evaluated. Cognitive ability was tested by Morris water maze task. Production of reactive oxygen species and origin targets including mitochondria membrane potential, respiratory chain complex I, complex III activities and mitochondria swelling degree were evaluated. Cytochrome oxidase was determined on its expression level by western blotting. Pinocembrin alleviated cognitive impairments in Morris water maze and decreased mitochondria reactive oxygen species production, in accordance with its improvements on complex I activity, membrane potential level, mitochondria swelling degree and cytochrome oxidase deficits. Pinocembrin could improve rat cognitive impairments induced by chronic cerebral hypoperfusion, contributed to its protections on brain mitochondria structure and function.
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Affiliation(s)
- Hong-Mei Guang
- National Center for Pharmaceutical Screening, Institute of Materia Medica, Chinese Academy of Medical Sciences and Peking Union Medical College, No.1 Xian Nong Tan Street, Beijing 100050, PR, China
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97
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Liu J, Jin DZ, Xiao L, Zhu XZ. Paeoniflorin attenuates chronic cerebral hypoperfusion-induced learning dysfunction and brain damage in rats. Brain Res 2006; 1089:162-70. [PMID: 16678139 DOI: 10.1016/j.brainres.2006.02.115] [Citation(s) in RCA: 70] [Impact Index Per Article: 3.9] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/08/2005] [Revised: 02/15/2006] [Accepted: 02/19/2006] [Indexed: 11/23/2022]
Abstract
Chronic cerebral hypoperfusion, a mild ischemic condition, is associated with the cognitive deficits of AD. Paeoniflorin (PF), a major constituent of peony root, was proved to be neuroprotective in middle cerebral artery occlusion model. In this study, we investigated whether PF could attenuate chronic cerebral hypoperfusion-induced learning dysfunction and brain damage in rat. Seven weeks after permanent bilateral occlusion of the common carotid arteries, the rats were tested in the Morris water maze. Subsequently, the animals were sacrificed and neurons, astrocytes and microglias were labeled with immunocytochemistry in hippocampus. PF at the dose of 2.5 mg/kg ameliorated cerebral hypoperfusion-related learning dysfunction and prevented CA1 neuron damage. Chronic cerebral hypoperfusion increased the immunoreactivity of astrocytes and microglias in hippocampus. The increase was prevented by PF at the dose of 2.5 mg/kg. Cerebral hypoperfusion also increased expression of nuclear factor-kappaB (NF-kappaB), mostly in astrocytes, but not in neurons. With the treatment of PF (2.5 mg/kg), NF-kappaB immunostaining was diminished in hippocampus. Our results demonstrated that PF could attenuate cognitive deficit and brain damage induced by chronic cerebral hypoperfusion and that suppression of neuroinflammatory reaction in brain might be involved in PF-induced neuroprotection.
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Affiliation(s)
- Jing Liu
- Shanghai Institute of Materia Medica, Shanghai Institutes for Biological Sciences, Chinese Academy of Sciences, 555 Zu Chong Zhi Road, Shanghai 201203, China
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98
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Antoine V, Rigaud AS. [Alzheimer's disease: cardiovascular risk factors must be assessed]. Rev Med Interne 2006; 27:21-31. [PMID: 15951064 DOI: 10.1016/j.revmed.2005.04.037] [Citation(s) in RCA: 8] [Impact Index Per Article: 0.4] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/01/2004] [Accepted: 04/22/2005] [Indexed: 12/28/2022]
Abstract
BACKGROUND Dementia is nowadays of major importance in public health. Alzheimer's disease and vascular cognitive impairments are its main aetiology in the elderly. The cause of Alzheimer's disease remains unknown. The factor initiating the physiopathology of this neurodegenerative disease is source of controversy. CURRENT KNOWLEDGE AND KEY POINTS The theory of a neurotoxicity initiated by amyloid deposition is questioned. A growing number of data suggest a central role of cardiovascular risk factors and alteration of arterial walls, inducing chronic brain hypoperfusion, as the primary trigger in the physiopathology of the disease. These data are based on epidemiological, physiopathological, neuroimaging, neuropathological and pharmacological studies. However, the exact link between arteriosclerosis, vascular cognitive impairment and Alzheimer's disease remains controversial. FUTURE PROSPECTS AND PROJECTS These debates point out the crucial importance of the assessment of cardiovascular risk factors, as a preventable cause, either of cognitive decline, morbidity and mortality. In this aim, major targets could be different when primary or secondary prevention are at stake. These controversies also suggest new research directions towards Alzheimer's disease physiopathology, and for pharmacological interventions aimed on the prevention of cognitive decline or the curative treatment for this disease.
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Affiliation(s)
- V Antoine
- Consultation de la mémoire, CHI Poissy-Les Maisonnées, rue du Champ-Gaillard, 78300 Poissy, France.
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99
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Manev H, Manev R. 5-Lipoxygenase (ALOX5) and FLAP (ALOX5AP) gene polymorphisms as factors in vascular pathology and Alzheimer’s disease. Med Hypotheses 2006; 66:501-3. [PMID: 16278051 DOI: 10.1016/j.mehy.2005.09.031] [Citation(s) in RCA: 27] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/15/2005] [Accepted: 09/20/2005] [Indexed: 11/22/2022]
Abstract
We first hypothesized in 2000 that a polymorphism of the human gene encoding the enzyme 5-lipoxygenase (5-LOX) might be associated with Alzheimer's disease. Only a little progress has been made in directly testing our proposal. However, additional important new data lead us to hypothesize that genetic variability not only in the 5-LOX gene, i.e., ALOX5, but also in polymorphism of the five-lipoxygenase activating protein (FLAP) gene, i.e., ALOX5AP, may be associated with Alzheimer's pathology. Studies in mice followed by several extensive clinical studies have identified ALOX5 and ALOX5AP polymorphisms as strong risk factors for atherosclerosis and cerebrovascular pathologies. New data point to a significant aggregation of vascular risk factors and risk of Alzheimer's disease. Preliminary findings in postmortem brain of Alzheimer's patients identified elevated 5-LOX immunostaining in this disease. We suggest that our hypothesis of a link between the ALOX5 and ALOX5AP gene polymorphisms and Alzheimer's disease could be tested in a clinical setting and in animal models, i.e., transgenic mice could be produced by crossing the available 5-LOX-deficient mice with the available transgenic mice models of Alzheimer's disease.
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Affiliation(s)
- Hari Manev
- Department of Psychiatry, The Psychiatric Institute, University of Illinois at Chicago, 1601 West Taylor Street, MC912, Chicago, IL 60612, USA.
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100
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Roher AE, Kokjohn TA, Beach TG. An Association with Great Implications: Vascular Pathology and Alzheimer Disease. Alzheimer Dis Assoc Disord 2006; 20:73-5. [PMID: 16493240 DOI: 10.1097/01.wad.0000201855.39246.2d] [Citation(s) in RCA: 14] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/26/2022]
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