AG to A transition at position -76 in the promoter region of the apoAI gene was previously identified, and the A-76 has been shown to be associated with high apoAI levels. The functional significance of the point mutation was assessed by analysing the DNA-protein binding and promoter activities of the different alleles. This data would suggest that the point mutation alters the function of the apoAI promoter as gel retention assays revealed that the G fragment (-140 to +10) formed an extra DNA-protein complex compared to the A fragment (-140 to +10). Concurrent with the altered DNA-protein interaction between the G and the A fragments, the transcriptional activities of the apoAI gene were found to also be altered. CAT assays have indicated a 1.91 fold increase in promoter activity of the A fragment as compared to the G fragment (-256 to +397). The difference in promoter activity was, however, highly dependent on the particular fragment used, as no difference was observed between the alleles when a fragment {-256 to +68) was used. In this study elements were identified in the region +68 to +397 that causes a reduction in the promoter activity of the G allele by 3.6 fold, whilst reducing the A allele activity by 2 fold. This data would suggest that the point mutation functionally alters the apoAI promoter activity via its interaction with other sequences especially in the region +68 to +397.

Agrégation de l'enseignement supérieur, Orientation sciences / info:eu-repo/semantics/nonPublished

Apolipoprotein E (apoE) occurs on the majority of plasma lipoproteins and plays a major role in the lipid metabolism in the periphery and in the central nervous system. ApoE is a polymorphic protein with three common isoforms, apoE2, apoE3 and apoE4, derived from respective alleles '2, '3 and '4. The aim of this study was to develop a sample pretreatment protocol combined with rapid mass spectrometry (MS)-based assay for simultaneous apolipoprotein profiling and apoE phenotype identification. This assay was validated in 481 samples from patients with stable atherosclerotic cardiovascular disease (ASCVD) and applied to study association with mild cognitive impairment (MCI) in the LIFE Adult study, including overall 690 study subjects. Simultaneous quantification of 8–12 major apolipoproteins including apoA-I, apoB-100 and apoE could be performed within 6.5 min. Phenotyping determined with the developed MS assay had good agreement with the genotyping by real-time fluorescence PCR (97.5%). ApoE2 isoform was associated with the highest total apoE concentration compared to apoE3 and apoE4 (p < 0.001). In the subgroup of diabetic atherosclerotic cardiovascular disease (ASCVD) patients, apoE2 isoform was related to higher apoC-I levels (apoE2 vs. apoE3, p < 0.05), while in the subgroup of ASCVD patients under statin therapy apoE2 was related to lower apoB-100 levels (apoE2 vs. apoE3/apoE4, p < 0.05). A significant difference in apoE concentration observed between mild cognitive impairment (MCI) subjects and controls was confirmed for each apoE phenotype. In conclusion, this study provides evidence for the successful implementation of an MS-based apoE phenotyping assay, which can be used to assess phenotype effects on plasma lipid and apolipoprotein levels.

Tsoi Lo Ming. / Thesis (M.Phil.)--Chinese University of Hong Kong, 2006. / Includes bibliographical references (leaves 99-109). / Abstracts in English and Chinese. / Acknowledgements --- p.I / Abstract --- p.II / Abstract in Chinese --- p.III / List of Abbreviations --- p.IV / List of Figures --- p.V / List of Tables --- p.VI / Table of Contents --- p.VII / Chapter Chapter 1 : --- Introduction / Chapter 1.1. --- Apolipoprotein and Lipoprotein Metabolism --- p.1 / Chapter 1.2. --- Molecular Information of ApoE --- p.2 / Chapter 1.3. --- Tissue Distribution of ApoE --- p.2 / Chapter 1.4. --- Functions of ApoE --- p.4 / Chapter 1.5. --- Genetic Polymorphism of ApoE --- p.7 / Chapter 1.6. --- Protein Structure and Characteristics of ApoE Isoforms --- p.9 / Chapter 1.7. --- Plasma and Cellular Expression Level of ApoE Isoforms --- p.12 / Chapter 1.8. --- Association between ApoE Isoforms and Plasma Lipid Profiles --- p.13 / Chapter 1.9. --- ApoE Polymorphisms and Pathophysiological Conditions / Chapter 1.9.1. --- Type III Hyperlipoproteinemia (Type III HLP) --- p.14 / Chapter 1.9.2. --- Alzheimer's Disease --- p.15 / Chapter 1.9.3. --- Atherosclerosis / Chapter 1.9.3.1. --- Atherosclerosis - An Inflammatory Process --- p.15 / Chapter 1.9.3.2. --- Role of ApoE in Atherosclerosis --- p.18 / Chapter (a) --- Functions Associated to Lipid Metabolism --- p.19 / Chapter (b) --- Functions Independent to Lipid Metabolism --- p.20 / Chapter 1.9.3.3. --- TNF-α and IL-6 in Atherosclerosis --- p.25 / Chapter 1.10. --- Macrophage Cytokine Expression and MAPKs / Chapter 1.10.1. --- Organization of MAPKs Signaling Pathway --- p.26 / Chapter 1.10.2. --- Lipopolysaccharide and MAPKs in Macrophage Cytokine Expression --- p.28 / Chapter 1.10.3. --- Regulation of Macrophage Cytokine Expression / Chapter 1.10.3.1. --- ERK1/2 and p38 MAPK Pathway --- p.30 / Chapter 1.10.3.2. --- Arachidonic Acid Metabolism --- p.30 / Chapter 1.11. --- Aim and Hypothesis --- p.31 / Chapter Chapter 2 : --- Materials and Methods / Materials / Chapter 2.1 --- Culture of ApoE-isoform-expressing J774A.1 Macrophage Cell Line --- p.32 / Chapter 2.2 --- RNA Extraction and Reverse Transcription-Polymerase Chain Reaction (RT-PCR) --- p.33 / Chapter 2.3 --- Protein Extraction and Quantification --- p.37 / Chapter 2.4 --- Enzyme-linked Immunosorbent Assay (ELISA) --- p.38 / Chapter 2.5 --- Western Blotting --- p.39 / Chapter 2.6 --- LPS Treatment --- p.42 / Chapter 2.7 --- MAPK Inhibitor Experiment --- p.43 / Methods / Chapter 2.8 --- Study on the Effect of Endogenously Expressed ApoE Isoforms on Macrophage Cytokine Secretion / Chapter 2.8.1. --- Establishment of ApoE-isoform-expressing Macrophages --- p.44 / Chapter 2.8.2. --- Semi-quantification of ApoE mRNA Level by RT-PCR / Chapter 1) --- Isolation of Total RNA --- p.45 / Chapter 2) --- RT-PCR --- p.46 / Chapter 2.8.3. --- Determination of ApoE Protein Expression Level by ELISA and Western Blot --- p.47 / Chapter 1) --- Quantification of Total Proteins --- p.48 / Chapter 2) --- ELISA --- p.48 / Chapter 3) --- Western Blot --- p.49 / Chapter 2.8.4. --- LPS Treatment --- p.51 / Chapter 2.8.5. --- MEK1/2 Inhibitor Experiment --- p.53 / Chapter 2.8.6. --- p38 Inhibitor Experiment --- p.54 / Chapter 2.9 --- Study on the Effect of Exogenous ApoE Isoform on Macrophage Cytokine Secretion --- p.55 / Chapter 2.10 --- Statistical Analysis --- p.55 / Chapter Chapter 3: --- Results / Changes of Inflammatory Properties Associated with Endogenous ApoE Isoform Expression in Macrophages / Chapter 3.1 --- Characterization of ApoE-isoform-expressing Macrophages --- p.56 / Chapter 3.1.1. --- Cell Lines with Stable Expression of ApoE Isoforms --- p.56 / Chapter 3.2 --- Cell Morphology Study --- p.58 / Chapter 3.3 --- Changes of IL-6 and TNF-α Secretion Associated with Endogenous ApoE Isoforms Expression / Chapter 3.3.1. --- In the Presence of Lipoproteins --- p.60 / Chapter 3.3.2. --- Serum/Lipoprotein-independent Effects of ApoE Isoforms --- p.63 / Chapter 3.4 --- The Effects of Endogenous ApoE Isoform Expression on the Activities of MAPK Signaling Pathways / Chapter 3.4.1. --- Study on the Activation Status and Expression of MAPKs --- p.66 / Chapter 1) --- ERK1/2 MAPK Pathway --- p.66 / Chapter 2) --- p38 MAPK Pathway --- p.69 / Chapter 3.4.2. --- IL-6 and TNF-a Secretion Among ApoE Isoforms in the Presence of MEK1/2 mhibitor --- p.72 / Chapter 3.4.3. --- IL-6 and TNF-α Secretion Among ApoE Isoforms in the Presence of p38 Inhibitor --- p.75 / Chapter Chapter 4 : --- Discussions / Chapter 4.1. --- Mouse Peritoneal Macrophage Cell Line J774A.1 as Cell Model --- p.79 / Chapter 4.2. --- Inflammatory Properties Associated with Endogenous ApoE Isoform Expression in Macrophages / Chapter 4.2.1. --- Expression Level of ApoE Isoform Transgenes in Mouse Peritoneal Macrophages --- p.80 / Chapter 4.2.2. --- Macrophage Activation by LPS --- p.81 / Chapter 4.2.3. --- Effect of Endogenous ApoE Isoform Expression on Cytokine Secretion and Signal Transduction in Macrophages --- p.82 / Chapter 4.3. --- Conclusions and Future Prospects / Chapter 4.3.1. --- Conclusions --- p.90 / Chapter 4.3.2. --- Future Prospects --- p.91 / Chapter Chapter 5 : --- Appendices / Chapter 5.1 --- Changes of Inflammatory Properties of Macrophages Supplemented with Exogenous ApoE Isoforms / Chapter 5.1.1. --- Changes of IL-6 and TNF-a Secretion in Macrophages Supplemented with Exogenous ApoE Isoforms --- p.92 / Chapter 5.1.2. --- Changes of Signal Transduction in Macrophages Supplemented with Exogenous ApoE Isoforms / Chapter 5.1.2.1. --- Study on the Activation Status and Expression of MAPKs / Chapter 1) --- ERK1/2 MAPK Pathway --- p.95 / Chapter 2) --- p38 MAPK Pathway --- p.97 / Chapter Chapter 6: --- Bibliography --- p.99

Thesis (Ph. D.)--University of Sydney, 2009. / Submitted in fulfilment of the requirements for the degree of Doctor of Philosophy to the Discipline of Pathology, Faculty of Medicine. Title from title screen (viewed Sept. 30, 2009) Includes bibliography. Also available in print form.

Abstract Atherosclerosis is a multifactorial disease with numerous genes and environmental factors affecting its intiation and progression. During the past years many candidate genes for atherosclerosis have been suggested, and it has also become evident that the immune system plays a part in atherogenesis. Early atherosclerotic changes can be effectively detected by measuring carotid artery intima-media thickness (IMT). In the present study the associations between IMT and polymorphisms of three candidate genes for atherosclerosis were studied: endothelial nitric oxide synthase (eNOS), apolipoprotein E (apoE) and paraoxonase-1 (PON1). To assess the role of immunological factors determining carotid atherosclerosis, CRP and circulating autoantibodies to oxidised LDL were studied in relation to IMT. The study population consisted of 519 hypertensive and 526 control subjects from a middle-aged population in Oulu, Finland. The results showed that the investigated polymorphisms of eNOS and PON1 genes were not associated with IMT, suggesting that these polymorphisms are not major risk factors for atherosclerosis in the general Caucasian population. A significant interaction between the apoE polymorphism and smoking in relation to IMT was observed among men, indicating that carriers of the ε4 allele may be particularly prone to the atherogenic effects of smoking. This interaction was especially clear in hypertensive subjects. CRP was strongly associated with IMT before adjusting for confounding factors. After the adjustment, this association diasppeared. The finding suggests that instead of early atherosclerosis CRP may be related to the later phases of the disease. This may partly explain the strong correlation between CRP and future cardiovascular events. IgM type of autoantibodies binding to oxidised LDL were inversely associated with IMT, and this finding remained after adjusting for previously known risk factors for atherosclerosis, implying a possible protective role for these antibodies in atherogenesis.

Lors d’une infection chronique, le virus de l'hépatite C (HCV) circule sous forme de lipoviroparticule (LVP) : particules hybrides associant des composants viraux (ARN, les protéines structurelles) et des composants cellulaires (apolipoprotéines, cholestérol). Au cours de ma thèse, nous nous sommes intéressés à identifier la plateforme d'assemblage du HCV, et le rôle du rassemblement des protéines virales par NS2 dans sa formation. Nous avons montré que des interactions de natures différentes sur la membrane du RE sont impliquées dans cette association protéique. Nos résultats suggèrent que des interactions complexes (directes ou via des « membranes résistantes aux détergents » (DRM)) entre les protéines complexées par NS2, peuvent immédiatement précéder la formation LVP. Nous avons également démontré que l’hétérodimère E1E2, les apolipoprotéines B et E (ApoB, ApoE) s’associent en un complexe de protéines dans le réticulum endoplasmique (RE) lorsqu'elles sont exprimées ensembles. Ce complexe se forme au début de l'assemblage du HCV, quelle que soit l'expression des autres protéines virales, et est conservée sur les LVP sécrétées. Basé sur ces données, nous avons proposé un mécanisme expliquant l’initiation de la morphogenèse des LVP. Ensuite, nous avons évalué l'importance de l'association E1E2/ApoE pour le cycle de vie du virus. Nous avons initié une étude pour identifier les acides aminés E1E2 impliqués dans l'interaction avec les apolipoprotéines. Avec ces données, nous souhaitons proposer une meilleure compréhension des mécanismes de la morphogenèse du HCV. / In chronic infection, the hepatitis C virus (HCV) circulates as lipoviral particles (LVP): hybrid particles associating viral (RNA, structural proteins) and cellular components (apolipoproteins, cholesterol). During my PhD, we were interested in identifying the HCV assembly platform, and the role of the association of the viral proteins by NS2 during its formation. We showed that different natures of interactions on the ER membrane are involved in this proteic association. Our results suggest that a complex interplay between proteins of the complex formed by NS2, directly or through “detergent resistant membranes” (DRMs) may be immediately followed by LVPs formation. We also demonstrated that E1E2 heterodimer, apolipoproteins B and E (ApoB, ApoE) associate as a protein complex in the endoplasmic reticulum (ER) when expressed together. This complex is formed early in HCV assembly, regardless the expression of other viral proteins, and is conserved on the secreted LVPs. Based on these data, we proposed a mechanism explaining LVP morphogenesis initiation. Then we assessed the importance of E1E2/ApoE association for viral life cycle. We initiate a study to identify the E1E2 amino acids involved in the interaction with apolipoproteins. With these data, we wished to provide a better understanding of the mechanisms of the HCV morphogenesis.

Indiana University-Purdue University Indianapolis (IUPUI) / Apolipoprotein M (apoM) is necessary for the formation of lipid-poor preβ-HDL particles, the initial precursor of HDL and acceptors of cholesterol efflux from peripheral cells. An assay to quantify apoM in serum is not widely-available, hampering the efforts to further understand apoM and to develop therapeutic methods to increase circulating levels of apoM. An antibody-free, high throughput mass spectrometry (MS)-based assay was developed to quantitatively measure apoM from a variety of species including human, mouse, and rat. Apolipoproteins were enriched by selectively binding to Liposorb, an affinity resin, followed by enzymatic digestion. This peptide mixture was separated by HPLC coupled in-line with tandem MS/ MS. Signal intensities from the MS/ MS fragmentation of apoM-specific peptides were measured simultaneously in a targeted method spanning many commonly used species. The same amount of purified human apolipoprotein A-IV uniformly labeled with 15N was spiked into all samples and was used as an internal standard to correct for any variation in sample handling and recovery. Assay variability and accuracy was statistically validated in a three-day spike recovery experiment to determine the working range of the assay. The concentration range for quantification of apoM using this assay was 11.2-500 nM, whereas average concentration of human apoM measured from a large sampling (n>100) was 370 nM. This assay was used to measure changes in apoM in mouse serum from a pre-clinical study that was designed to evaluate the effects of a microsomal triglyceride transfer protein (MTTP) inhibitor. All measured lipoproteins and apolipoproteins showed a dose-dependent decrease in concentration and the response of apoM closely followed the response of HDL. In a clinical application of the assay, apoM was measured in human serum to evaluate the effects of two cholesterol-lowering compounds, a statin drug and an experimental PPAR-α agonist. ApoM levels did not change with PPAR-α agonist or combination treatments, but significantly decreased with atorvastatin. The measurement of apoM provided additional information on the effects of these drug treatments that previously could not be measured. The availability of a quantitative assay for apoM provides a valuable tool in the development of cardio-protective therapeutics and understanding the mechanisms of these drugs. / Monarch LifeSciences, Eli Lilly and Company

A relação entre transferência de lipídeos, idade e aterogênese são complexas e ainda não estão claras. É possível que a troca de lipídeos esteja alterada com a avançar da idade e relacionada com a Doença Arterial Coronariana (DAC). O objetivo deste trabalho foi verificar a hipótese se em indivíduos mais jovens a habilidade da HDL de receber lipídeos é diferente de indivíduos mais velhos com e sem a evidência clínica da DAC. Dentro desses aspectos, foram determinados o diâmetro da partícula desta lipoproteína, a atividade da Paraoxonase (PON1) e sua capacidade de receber lipídeos. Para tanto, foram estudados 86 indivíduos divididos em quatro grupos: adulto jovem (25±4), meia-idade (42±8), idosos sem evidência clínica de DAC (75±6) e idosos com DAC (74±5). Uma nanoemulsão artificial rica em colesterol (LDE) marcada com 3H-TG e 14C-CL ou 3H-CE e 14C-FL foi incubada com plasma. Após a precipitação de outras lipoproteínas, o sobrenadante contendo HDL foi separado e em seguida, medida a radioatividade. O diâmetro da HDL foi medido por laser scattering (nm). Foram constatadas diferenças significativas entre as taxas de transferência de 3H-éster de colesterol (CE) entre os grupos: adulto jovem (3.7±1.0%); meia idade (4.1 ±0.7%) e idosos (5.3±1.8%);p= 0.024. Também ocorreu diferença entre as taxas de transferência do 14C-fosfolipídeo (FL): adulto jovem (18.7±4.6%), meia idade (18.3 ±4.0%) e idosos (20.6±5.3); p=0.0368. Com relação ao tamanho das partículas de HDL, foi encontrada diferença entre os grupos: os grupos adulto jovem (8.9± 0.3nm) e meia idade (8.9± 0.3nm) apresentaram menores diâmetros de HDL quando comparados ao do grupo de idosos sem evidência clínica da DAC (9.7± 1.6);p= 0,0444. As transferências de lipídeos foram expressas em % de radioatividade. A idade correlacionou-se positivamente com a taxa de transferência do 3H- éster de colesterol (r=0.3365; p=0.0036), com a concentração de colesterol total (r=0.4965; p=0.0001) e com a concentração de HDL colesterol (r=0.3559; p=0.0023). Também houve correlação positiva com o tamanho de HDL (r=0.3695; p=0.0013). Em princípio, os indivíduos idosos sem evidência clínica da DAC, aparentemente têm alguma proteção contra a mesma. Desse modo, com o intuito de saber se os resultados encontrados no presente trabalho sustentam a afirmação acima, foi realizada a comparação desse grupo com um grupo de idosos que apresentavam a DAC. O grupo com DAC apresentou menor tamanho de partícula de HDL (8,7±0,7). As taxas de transferência de 3H-CE e de 14C-FL também foram menores neste grupo (3H-CE=3,1 ±2,3 e 3H-TG= 5,1 ±1 ,6). Devido ao importante papel antiaterogênico da HDL, esses resultados podem ser relevantes para estabelecer novos mecanismos existentes entre os aspectos qualitativos dessa lipoproteína, o avanço da idade e a presença da DAC. / The relationship between transfer of lipids, age and atherogenesis are complex and yet unclear and is possible that the shift of lipids to HDL may be altered by the aging process and related with coronary artery disease (CAD). We tested the hypothesis whether in younger patients the ability of HDL to receive lipids is different from that of elderly patients with or without CAD. Inside of these aspects, the HDL size, the activity of Paraoxonase (PON1) and its capacity to receive lipids was determined. It was studied, 25 younger, 25 middle age, 36 elderly patients with a coronariography and/or a perfusion scintilography on the last 6 months (11 with CAD, 74±5 yo; and 25 patients without proved CAD, 75±6 yo). An artificial cholesterol-rich nanoemulsion labeled with 3H-TG and 14C-FC or H-CE and 14C-PL was incubated, per 1 hour, with plasma. After chemical precipitation of apoB-containing lipoproteins and the nanoemulsion, the supernatant containing HDL was counted for radioactivity. The HDL diameter was measured by laser-light-scattering. Transfer of CE and PL to HDL was smaller in young patients than in the elderly patients without CAD, but the transfer of the other lipids are equal (CE: young= 3.7±1.0%; middle age= 4.1 ±0.7%; elderly without CAD= 5.3±1.8%; p= 0.024 and PL: young= 18.7±4.6%; middle age= 18.3 ±4.0%; elderly without CAD= 20.6±5.3; p=0.0368). The HDL size was greater in elderly group without CAD (9.7± 1.6nm) than in younger (8.9± 0.3nm) and middle age patients (8.9± 0.3nm); p=0,0444. Transfer of lipids to HDL was expressed as % of total incubated radioactivity. The age positively correlated with the transfer of CE (r=0.3365; p=0.0036), with the total cholesterol concentration (r=0.4965; p=0.0001) and with the HDL concentration cholesterol (r=0.3559; p=0.0023). Also had positive correlation with the size of HDL (; p=0.0013). In principle, the aged patients without CAD, have some protection against the same one. In this aspect, with intention to know if the results found in the present work support the affirmation above, was compared this group with a group of aged that presented the CAD. Comparing elderly patients without CAD with elderly patients with CAD, the transfer of CE and FL as well as HDL size was smaller in the CAD group (CE=3.1±2.3 and TG= 5.1±1.6; 8.7±0.7nm). Due to HDL important antiatherogenic roles, this result can be relevant to establish new mechanisms and risk factors in aging and in CAD.

Diversos estudos de ressonância magnética (RM) em idosos saudáveis tem avaliado a relação entre envelhecimento, diminuições volumétricas de substância cinzenta (SC) e desempenho cognitivo, usando desenhos de corte transversal e testes de correlação. No entanto, poucos estudos de volumetria baseada em voxel (VBM) tem relatado a diminuição de SC em idosos saudáveis com medições repetidas de RM nos mesmos indivíduos, e nenhum desses estudos longitudinais investigaram a relação entre as mudanças de SC e desempenho cognitivo ao longo do tempo. Além disso, não está claro em achados longitudinais qual a extensão da influência do APOE?4 sobre as reduções de SC em idosos saudáveis. Foram inicialmente avaliados 187 sujeitos idosos (acima de 65 anos) da comunidade, e após 3 anos, uma subamostra de 55 sujeitos realizaram um segundo exame de RM estrutural em equipamento de 1,5 Tesla, bem como reavaliação cognitiva com instrumentos padronizados e validados transculturalmente. Todos os sujeitos foram genotipados para determinar a presença/ausência do alelo APOEe4, bem como a avaliação clínica do grau do risco cardiovascular de acordo com escores de Framingham (FRS). Usando a técnica de VBM, testamos as hipóteses de que: a progressão da perda do desempenho cognitivo está associada a diminuições volumétricas de SC ao longo de 3 anos, envolvendo a região hipocampal e os neocórtices temporal e frontal; e perdas cognitivas associadas à diminuição progressiva de SC cerebral serão maiores em indivíduos com alto risco cardiovascular e em portadores de alelo da APOEe4. Foram encontradas reduções globais e regionais de SC no tálamo direito e giro parahipocampal esquerdo (p < 0,05, family-wise error corrigido para comparações múltiplas por todo o cérebro). Estes resultados não foram afetados pela influência da APOEe4. Foi detectada uma tendência (p=0,093) na correlação entre o grau de declínio cognitivo e redução volumétrica no tálamo direito. Este resultado se manteve quando um coeficiente parcial de correlação foi calculado levando em conta as variações nos escores FRS. Independentemente da APOEe4, as análises longitudinais de VBM mostraram que a região do hipocampo e tálamo são áreas críticas onde a redução de SC e maior que a redução volumétrica global em idosos saudáveis. Os resultados da associação entre a redução de SC no tálamo e a mudança no desempenho cognitivo ao longo do tempo, apoia o recente reconhecimento do papel do tálamo no declínio cognitivo sutil associado ao envelhecimento saudável / A number of magnetic resonance imaging (MRI) studies have investigated the relationship between aging, reduced gray matter (GM) volumes in the brain and cognitive performance, using cross-sectional designs and correlation tests. However, very few VBM studies have documented GM decrements in healthy elderlies with repeated MRI measurements obtained in the same subjects, and none of these longitudinal studies investigated the relationship between GM deficits and changes in cognitive performance over time. Also, it is unclear the extent to which the APOE e4 allele influences on longitudinal findings of GM reductions in healthy elderlies. Were initially evaluated 187 elderly subjects (over 65 years); after 3 years, a sub-sample of 55 individuals underwent a second MRI examination in a 1.5 Tesla equipment, and a cognitive re-evaluation using a structured, transculturally validated neuropsychological battery. All subjects also underwent genotyping for ascertainment of the presence of the APOEe4 allele, as well as clinical assessment of cardiovascular risk according with Framingham scores (FRS). Using voxel-based morphometry (VBM), we will test the following hypotheses: the progression of cognitive decline will be associated with volumetric reductions of GM over three years, involving the hippocampal region and the temporal and frontal neocortices; cognitive decline associated with progressive GM volume reductions will be greater in individuals with higher cardiovascular risk and carriers of the APOE?4 allele. We found global GM reductions as well as regional GM decrements that were significant in the right thalamus and left parahippocampal gyrus (p < 0.05, family-wise error corrected for multiple comparisons over the whole brain). These findings were not affected by APOE e4. A trend correlation (p=0.093) was detected between the degree of cognitive decline over time and right thalamic volume shrinkage. This finding retained statistical significance when a partial coefficient of correlation was calculated taking into account variations in FRS scores. Irrespective of APOEe4, longitudinal VBM analyses show that the hippocampal region and thalamus are critical sites where GM shrinkage is significantly greater than the degree of global brain volume reduction in healthy elders. The trend towards an association between thalamic GM decrement and cognitive performance change over time supports the recently recognized role of the thalamus in the subtle cognitive decline associated with healthy human aging