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1
Dinkel, Regina Elke. „In-vivo Metabolismus der VLDL-Apolipoproteine ApoB, ApoCIII und ApoE“. Diss., lmu, 2002. http://nbn-resolving.de/urn:nbn:de:bvb:19-3562.
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Reverté, Soler Ingrid. „Neurobehavioural effects associated with postnatal exposure to decabromodiphenyl ether in apoe2, apoe3 and apoe4 transgenic mice“. Doctoral thesis, Universitat Rovira i Virgili, 2012. http://hdl.handle.net/10803/76782.
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El Decabromodifenil èter (BDE-209) és un retardant de la flama àmpliament utilitzat i font de preocupació a causa de la toxicitat mostrada per altres Difenil Èters Polibromats (PBDEs). La presència de PBDEs en la llet materna fa preocupant la seva exposició durant el desenvolupament. Pensem que l’exposició primerenca a BDE-209 pot produir efectes a llarg termini i interactuar amb factors genètics, com el genotip de l’ApolipoproteinaE. Ratolins portadors de les diferents isoformeshumanes de l’ApoE foren tractats amb una dosi oral aguda de 0, 10 o 30 mg / kg de BDE-209 en el dia postnatal 10 i van ser avaluats per neurocomportament durant el desenvolupament, a l'edat adulta i la vellesa. L’exposició a BDE-209 indueix un retard en el desenvolupament físic i neuromotor i en la compactació de la mielina en els ratolins ApoE2, disminueix els nivells de tiroxina lliure en les femelles adultes i disminueix l'activitat en ratolins ApoE4. Els efectes més consistents durant tota la vida s'observen en ratolins ApoE3 i consisteixen en problemes d'aprenentatge als 4 mesos, i problemes d'aprenentatge i memòria i un augment de l'ansietat als 12 mesos.Decabromodiphenyl Ether (BDE-209) is a flame retardant widely used and source of concern because ofthe toxicity showed by other Polibrominateddiphenyl ethers (PBDEs). The presenceof PBDEs in human’s breast milkmakes worrying its exposure during development. We hypothesised that an early exposure to BDE-209 can induce long-term impairments and interact with genetic factors, such as ApolipoproteinE genotype. Mice carrying the different Human ApoE isoforms treated with an acute oral dose of 0, 10 or 30 mg/kg of BDE-209 on postnatal day 10 were assessed for neurobehaviourduring development, in young adulthood and old age. BDE-209 exposure inducesadelay in physic and neuromotordevelopment and in myelin compaction in ApoE2 mice, decreases the levels of free thyroxin in adult femalesand decreases activity in ApoE4 mice. The most consistent effects across the lifespan are observed in ApoE3 mice and consist of impaired learning at 4 months, and impaired learning and memory and increased anxiety at 12 months.
3
Cambon, Karine. „Influence of ApoE polymorphism on synaptic morphometry during aging in the dentate gyrus of ApoE knockout and human ApoE transgenic mice“. Thesis, [n.p.], 2000. http://oro.open.ac.uk/19118/.
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Lundbäck, Daniel. „Alkoholkonsumtion och episodiskt minne.Kan APOE genen vid olika konsumtionsnivåer ha betydelse?“ Thesis, Stockholms universitet, Psykologiska institutionen, 2013. http://urn.kb.se/resolve?urn=urn:nbn:se:su:diva-88448.
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I denna studie undersöktes om relationen mellan alkoholkonsumtion och episodiskt minne skiljer sig beroende på vilken allele av APOE genen en person har. Undersökningsdeltagarna delades upp i fyra grupper, medelålders män, medelålders kvinnor, äldre män och äldre kvinnor. Utbildningsnivå och ålder inom varje åldersgrupp användes som kovariat. APOE delades upp på 4 bärare och icke bärare. Några signifikanta interaktionseffekter mellan alkoholkonsumtion och APOE framkom inte i någon grupp. I gruppen medelåldersmän hittades en signifikant huvudeffekt av alkoholkonsumtion, där de som avstod från alkohol presterade sämre än de med olika nivåer av alkoholkonsumtion. Liknande tendenser syntes i de tre övriga grupperna där undersökningsdeltagare som avstod från alkohol presterade sämst, dock inte signifikant. En anledning till att de som konsumerar alkohol presterar bättre på episodiskt minnestest än de som inte dricker förmodas vara alkoholens positiva effekter på det kardiovaskulära systemet. Ytterligare forskning på området behövs då andra faktorer, så som hur mycket som dricks vid ett enskilt tillfälle, kan vara mer avgörande.Betula
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Hua, Jennifer. „Rôle des récepteurs P2X4 dans la dégradation d’ApoE : implication dans la maladie d’Alzheimer“. Thesis, Montpellier, 2019. http://www.theses.fr/2019MONTT021/document.
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Les récepteurs purinergiques P2X4 (P2X4R) sont des récepteurs canaux exprimés par lesneurones et les microglies du système nerveux central et sont impliqués dans de nombreuxprocessus physiologiques et pathologiques. Des études préliminaires, menées au sein dulaboratoire, ont permis de mettre en évidence une interaction entre P2X4R etl’Apolipoprotéine E (ApoE), ainsi qu’une augmentation d’ApoE dans les macrophages et lesmicroglies provenant de souris déficientes pour P2X4R. Basée sur ces observations, lapremière partie de cette thèse a cherché à caractériser les mécanismes impliquant P2X4R danscet effet. ApoE étant un facteur de risque majeur dans la maladie d’Alzheimer, la deuxièmepartie de cette thèse a été consacrée à étudier l’implication de P2X4R dans cette pathologie.Les résultats présentés montrent que P2X4R module l’activité de la cathepsine B, enzymeresponsable de la dégradation lysosomale d’ApoE. L’utilisation de souris APP/PS1 a permisde montrer que l’absence de P2X4R conduit à une amélioration des capacités mnésiques, unediminution de la concentration de peptide Aβ soluble ainsi qu’à une augmentation d’ApoEmicrogliale.Ces résultats indiquent que P2X4R régule la dégradation d’ApoE par un mécanismedépendant de la cathepsine B, et que son invalidation permet d’améliorer les symptômescognitifs de la maladie d’AlzheimerP2X4 receptors (P2X4R) are purinergic ion channels expressed on neurons and microglia inthe central nervous system. They have been widely studied and have been implicated in manyphysiological and pathological processes. Previous studies conducted in the laboratoryrevealed an interaction between P2X4R and the Apolipoprotein E (ApoE), as well as anincrease in ApoE level in primary macrophages and microglia obtained from mice lackingP2X4R. Based on these results, this thesis aimed to decipher the mechanisms underlyingP2X4R regulation of ApoE levels. In addition, ApoE being a major risk factor forAlzheimer’s disease, part of this work investigated potential implications of P2X4R in thispathology.Results show that P2X4R modulates cathepsin B activity, which in turn promotes ApoElysosomal degradation. APP/PS1 mice lacking P2X4R show an increase in cognitiveperformances, a decrease in soluble Aβ peptide and an increase of microglia ApoE level.These results support that P2X4R modulates ApoE degradation in a cathepsin B-dependantmanner and that its invalidation leads to an improvement in Alzheimer’s pathology
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Wassef, Hanny. „Synthesis and secretion of apoC-I and apoE by human SW872 liposarcoma cells“. Thesis, McGill University, 2004. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=82447.
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Apolipoprotein C-I (apoC-I) plays an important role in the metabolism of plasma triglyceride levels and cholesterol metabolism. Little is known about the regulation of apoC-I production by human adipocytes. Aim. To investigate the effect of different tissue culture conditions on the synthesis and secretion of apoC-I and apoE in human SW872 liposarcoma cells and to study the effects of apoC-I overexpression in these same cells. Methods. SW872 cells were grown in DMEM/F-12 (3:1, v/v). QPCR was used to quantify mRNA synthesis. ELISAs were used to quantify intracellular and extracellular proteins. Colorimetric reaction kits were used to analyze intracellular cholesterol and triglyceride concentrations. Results . Maturation experiments revealed that after 17 days in culture, SW872 cells contained significantly more cholesterol (100%) and triglyceride (3-fold). Cell maturation was associated with significantly higher levels of apoE mRNA (+200%) but not apoC-I mRNA (-50%). The cells secreted more apoC-I (+110%) and apoE (+340%). Cellular apoC-I increased 620% and apoE increased 1540%. Treatment of cells during maturation with insulin (0, 10 or 1000 nM) significantly reduced the secretion of apoC-I and apoE (-14% and -56%, respectively) and intracellular apoC-I and apoE (-10% and -12%, respectively. Overexpression of apoC-I in SW872 cells resulted in increased cell number (+70%) and decreased lipids per cell (-32% triglyceride, -36% cholesterol) as compared to controls. Conclusion. These results suggest that apoC-I and apoE production is differentially regulated at the transcriptional level in adipocytes and that apoC-I and apoE play a role in the maturation of human adipocytes and may have an important role in mediating or regulating cell lipid accumulation. As well, overexpression of apoC-I in SW872 cells impedes cellular lipid accumulation and stimulates cellular proliferation.
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Sleiman, Lyne. „The Role of cIAP2 in Early and Late Atherosclerosis Lesion Development“. Thesis, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20226.
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Cellular Inhibitor of Apoptosis 2 (cIAP2) belongs to the IAP family, a group of endogenous proteins that inhibit apoptosis. However, the physiological role of cIAP2 remains poorly defined. Knock-out (KO) and wild type (WT) mice were used to examine the effect of cIAP2 protein on the progression of atherosclerosis in apoE -/- mice. Following the high-fat diet period of 4 and 12 wks, tissues were harvested and analysis focused on the aortic root, the aortic arch, the descending aorta, and the blood. Ex vivo results show a significant decrease in aortic arch lesion area in KO vs. WT in both study groups. Results also show a decrease in aortic root lesion size in KO vs. WT in both study groups. These results support that cIAP2 is an important survival factor for lesion-associated macrophages, since loss of cIAP2 expression in this mouse model reduced atherosclerotic lesion development.
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D'EUGENIO, Ottavio. „VALUTAZIONE DI FATTORI DI RISCHIO GENETICI SU BASE POLIMORFICA NELLA MALATTIA DI ALZHEIMER“. Doctoral thesis, La Sapienza, 2006. http://hdl.handle.net/11573/917163.
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Evans, Vanessa. „Intramuscular gene transfer of apolipoprotein E (ApoE) to reverse hyperlipidaemia and atherosclerosis in ApoE-deficient mice“. Thesis, University College London (University of London), 2007. http://discovery.ucl.ac.uk/1444704/.
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Plasma ApoE has multiple atheroprotective actions, including clearance of cholesterol-rich remnant lipoproteins, and is an attractive gene therapy candidate to treat atherosclerosis. Here, I focus on the single intramuscular injection of an ApoE-expressing vector, non-viral DNA (plasmid) or adeno-associated virus (AAV), as a safe and effective treatment to alleviate hypercholesterolaemia and atherosclerosis in ApoE-deficient (ApoE" ") mice. Firstly, I constructed expression plasmids harbouring human ApoE3 cDNA, driven by two muscle-specific (CK6 and C512) and one ubiquitous (CAG) promoter. The CAG-driven plasmid was injected into tibialis anterior muscles, pre-treated with hyaluronidase, of young ApoE"'" mice and, provided the injection site was electropulsed, gave strong local expression of ApoE3 protein at 1 week (13.38 7.46jig ApoE3 per muscle). This amount was much greater than the CK6- and C512-driven plasmids (0.61 0.38 and 0.45 0.38/ig, respectively), but in all mice plasma ApoE3 levels were below the detection limit (<15ng/ml) and did not ameliorate the hyperlipidaemia. Next, I generated both single-stranded (ss) and self- complementary (sc) AAV2/7 vectors. At 1, 2 and 4 weeks, ApoE was readily measured in the plasma of ApoE'" mice injected with the ssAAV2/7.CAG vector, reaching levels of 1.4/ig/ml, whereas plasma ApoE was again undetected after administration of the CAG-driven plasmid . By contrast, both ssAAV2/7 and scAAV2/7 vectors driven by the muscle-specific promoters performed poorly and ApoE could not be detected in plasma. Therefore, for my final experiment I pseudotyped the ssAAV2.CAG.ApoE3 vector with the robust serotypes 8 and 9, and directly compared their efficiency with ssAAV2/7.CAG.ApoE3 in ApoE"" mice. After 1 week plasma ApoE had reached 2ug/ml in ssAAV2/7 and ssAAV2/8-treated animals, and persisted at l-2ug/ml throughout the 13 week study, whereas the ssAAV2/9 vector was less effective and gave only 0.5ug ApoE/ml. Disappointingly, however, these concentrations of plasma ApoE were still insufficient to have hypolipidaemic effects or to inhibit plaque development in the brachiocephalic artery. In conclusion, although electropulsation enhanced plasmid-mediated transgene expression from skeletal muscle, rAAV was a more efficient gene transfer vector and modest additional optimisation should provide therapeutic levels of ApoE3 in plasma.
10
Rantsi, P. (Petra). „Apoe 4-alleelien rooli saamelaisväestön muistisairauksissa“. University of Oulu, 2017. http://urn.fi/URN:NBN:fi:oulu-201711083079.
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Alzheimerin tauti (AT) on yleisin etenevä muistisairaus. Eteneviin muistisairauksiin luetaan myös aivoverenkiertosairauden muistisairaus, Lewyn kappale- patologiaan liittyvät aivoja rappeuttavat sairaudet ja otsa-ohimolohkorappeumat. Elimistön rasva- aineenvaihduntaan liittyvän apolipoproteiini E4- (ApoE4) alleelin on todettu olevan sydän- ja verisuonisairauksien, kuten myös AT:n myöhemmällä iällä alkavan muodon geneettinen riskitekijä. ApoE4-alleelin yhteyttä muihin eteneviin muistisairauksiin ei ole osoitettu.
Vaikka ApoE4:n roolia muistisairauksien ja etenkin AT:n riskitekijänä on tutkittu maailmalla runsaasti eri väestöissä, ApoE4-alleelin roolia saamelaisten muistisairauksissa ei ole aiemmin tutkittu. Yksittäisen aiemman tutkimuksen perusteella Suomen saamelaisista 5%:lla on E2-, 64%:lla E3- ja 31%:lla E4- alleeli. Tutkimuksen tavoitteena oli selvittää ApoE4- alleelin esiintyminen Suomen Lapin saamelaisväestön muistisairauspotilailla. Tutkimukseen osallistui yhteensä 50 saamelaista potilasta, joilla oli todettu muistihäiriö tai muistisairauden diagnoosi. Laskimoverinäytteet ApoE-fenotyypitystä varten ja kyselykaavakkeiden tiedot kerättiin saamea puhuvan sairaanhoitajan avulla.
ApoE4- alleeli esiintyi yhteensä 78%:lla potilaista (n=39). Apolipoproteiini E-fenotyyppiä E3/E3 kantoi 22% (n=11) potilaista, E3/E4 62% (n=31), E4/E4 14% (n=7) ja E2/E4 2 % (n=1) tutkittavista. Verrokkeja tutkimuksessa ei ollut, mutta tuloksia verrattiin aiempaan tietoon ApoE-alleelien esiintyvyyteen sekä saamelaisilla että maailmanlaajuisesti AT:a sairastavilla. Yhteenvetona voidaan todeta, että ApoE4 on tärkeä riskigeeni muistisairauksille myös saamelaisväestössä. Lisäksi huomionarvoista on, että ApoE4-alleelin esiintyminen saamelaisväestön muistipotilailla on korkein, mitä on kuvattu missään aiemmassa muistipotilaiden ja AT-tutkimuksissa.
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Carvalho, Liliana Patrícia Rodrigues de. „Genetic profiling of ApoE in dementia“. Master's thesis, Universidade de Aveiro, 2012. http://hdl.handle.net/10773/10720.
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Mestrado em Biomedicina MolecularA demência é uma das principais causas de incapacidade entre os idosos, afetando mais de 36 milhões de pessoas em todo o mundo. É caracterizada pela deterioração progressiva das funções cognitivas, resultando em dificuldades no desempenho das atividades diárias do indivíduo. A idade de aparecimento dos sintomas, bem como a sua taxa de progressão, são variáveis entre a maior parte das demências, sendo estas geralmente caracterizadas por uma natureza progressiva, aumentando de gravidade ao longo do tempo. Entre os tipos mais frequentes de demência encontram-se a Doença de Alzheimer (DA), Demência Vascular, Demência de Corpos de Lewy e Demência Frontotemporal. O diagnóstico diferencial das demências é realizado tipicamente por testes neuro-psicológicos (para a exclusão de outras demências) e por exames imagiológicos. Contudo, muitos dos sintomas clínicos característicos podem sobrepor-se entre os diversos tipos de demência, o que pode constituir um problema devido a falta de especificidade e erros de diagnóstico. A compreensão dos fatores de risco ambientais e genéticos que podem modular o aparecimento e/ou progressão de doenças abre novas perspetivas relativamente à gestão destas neuropatologias. O gene da apolipoproteína E (ApoE) é reconhecido como o maior fator de risco na demência, desempenhando um papel central em particular no desenvolvimento da DA, sendo que os portadores do alelo ε4 são mais suscetíveis para a doença. Além disso, possíveis associações foram também propostas entre este gene e outras doenças neurológicas, sendo no entanto estes dados ainda controversos. Assim, o objetivo principal deste trabalho consistiu em determinar as frequências alélicas e genotípicas do gene ApoE num grupo de estudo piloto de pacientes com demência na região de Aveiro. Este grupo foi subdividido com base no diagnóstico neuroquímico, no qual foram avaliados os níveis de Aβ1-42, Tau-total e fosfo-Tau 181 no líquido cefalorraquidiano dos pacientes. Como resultado, observou-se que o alelo ε3 foi o mais frequente no grupo total, independentemente do tipo de patologia, e que o alelo ε2 foi o menos comum. O alelo ε4 foi de facto mais frequente em pacientes com DA do que em pacientes com outras neuropatologias, o que está de acordo com a relação proposta por outros autores. Adicionalmente, foi possível verificar que a frequência deste alelo nos pacientes com patologia amilóide é semelhante à observada no grupo DA, sugerindo um papel relevante para o ApoE no metabolismo e acumulação cerebral do Aβ. Consequentemente, estes indivíduos podem ter uma maior suscetibilidade para o desenvolvimento de DA no futuro. Deste modo, os nossos dados corroboram a ideia de que o alelo ε4 é um forte fator de risco para a DA e que deve ser considerado como um teste genético relevante que pode contribuir para o diagnóstico clínico da demência.
Dementia is one of the leading causes of disability among the elderly, affecting over 36 million people worldwide. It is characterized by progressive deterioration in cognitive functions that impair the successful performance of daily living activities. Most forms of dementia are progressive in nature, increasing in severity over time, with the rate of symptoms progression and the age at onset differing among the major dementing disorders. The most frequent types of dementia include Alzheimer´s Disease (AD), Vascular Dementia, Dementia of Lewy bodies and Frontotemporal Dementia. Differential diagnosis of dementia is typically done by neuropsychological testing (for exclusion of other dementias) and neuroimaging investigations. However, many of the clinical symptoms typical of dementia may overlap across dementia subtypes, which may constitute a diagnosis problem leading to lack of specificity and misdiagnosis. Understanding the environmental and genetic factors that modulate risks and outcomes of diseases can open new perspectives on the management of these neurological disorders. Apolipoprotein E gene (ApoE) is recognized as the major genetic risk factor in dementia, in particular playing a central role in AD development, being that ApoE allele ε4 carriers are more susceptible to disease. Furthermore, putative associations have also been proposed between this gene and other neurological disorders, nonetheless controversial data have been reported regarding these aspect. Hence, the aim of this work was to determine ApoE genotypic and allelic frequencies in a pilot study group of dementing patients from the catchment area of the “Hospital de São Sebastião” in “Santa Maria da Feira”. This group was subdivided according to their neurochemical-based diagnosis of dementia, in which Aβ1-42, phospho-Tau 181 and total-Tau levels in patients’ cerebrospinal fluid were evaluated. In this study, we could observe that allele ε3 was the most frequent in the total study group, independent of the type of pathology, and that allele ε2 was the less frequent. Allele ε4 was in fact more frequent in AD patients than in other neurological disease patients, in agreement with the proposed link established by other authors. Additionally, we also find that allele ε4 frequency in patients suffering from amyloid pathology is similar to that observed in AD group, suggesting a role for ApoE in Aβ metabolism and brain accumulation. Potentially, these patients have a higher susceptibility to develop AD pathology in the future. Thus, our data supports the idea that ApoE allele ε4 is a strong risk factor for AD development and that it may be considered as a relevant genetic test that may assist in the clinical diagnosis of dementia.
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Wong, Clement Cheuk Man. „Plasma Apolipoprotein E Concentration In Type 2 Diabetes“. Thesis, The University of Sydney, 2018. http://hdl.handle.net/2123/20997.
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As one of the most important proteins in human lipid metabolism, apolipoprotein E (apoE) is also one of the most well studied apolipoproteins. ApoE has an undisputable role in the plasma clearance of atherogenic triglyceride-rich lipoproteins via receptor-mediated hepatic uptake. For years, apoE has been touted to play a protective role in atherosclerosis. Both quantitative and qualitative changes of apoE are well-known to cause a number of rare dyslipidaemia syndromes. Until recent times, research efforts have mainly focused on the discovery of the differential risk of atherosclerotic vascular disease and Alzheimer’s dementia associated with specific apoE isoforms. Despite contemporary knowledge on the effect of common apoE alleles on cardiovascular risk, little is known if the plasma levels of the gene product, i.e. apoE, is also independently associated with cardiovascular risk. There have also been studies that demonstrated possible links between apoE and renal diseases. Recent population-based studies on healthy, mostly non-diabetic subjects have yielded conflicting results. To this day, no consensus has yet been reached regarding the role of plasma apoE concentration in the prediction of atherosclerotic and renal disease outcomes. Our study, based on the subjects of the FIELD randomised control trial cohort, is the largest one to-date on plasma apoE levels on a purely diabetic population. We were the first to characterise and describe, in detail, the apoE concentration profile in type 2 diabetic subjects, and its relationship with other biochemical markers and clinical measures. We also confirmed that some of these variables are also, in fact, independent predictors of the apoE levels in diabetes. In Chapter 3, we described in detail the statistical distribution of plasma apoE concentration in the FIELD cohort. We obtained the reference range for type 2 diabetic subjects and compared this with those of the healthy non-diabetic populations from previous studies. We assessed the statistical correlation between diabetic plasma apoE concentration with other important (apo)lipoproteins, biochemical markers and clinical parameters. We compared the clinical and biochemical differences between individuals in the highest and lowest quintiles of apoE and described the metabolic phenotypes associated with both high and low plasma ApoE levels. We found that diabetic apoE concentration is on average higher than non-diabetics, and that apoE concentration in diabetics is quite strongly correlated with female gender, systolic and diastolic blood pressures, smoking, atherogenic lipoproteins, body-mass index as well as C-peptide and hepatic transaminases. These parameters were also present, or higher, in the highest apoE quintile subjects compared to the lowest. Thus, we were able to deduce that apoE levels were highest in those who smoked and were obese, and who had hypertension, dyslipidaemia, hepatic steatosis, increased insulin resistance and those with features of metabolic syndrome – these are clearly adverse cardiometabolic features. In Chapter 4, we evaluated the influence of various important clinical and biochemical variables in the prediction of diabetic plasma apoE concentration, using multi-variable linear regression analysis, also taking into account the complex interactions amongst the covariates themselves. We identified the strongest independent predictors of diabetic apoE plasma levels and compared the influence of each predictor in relation to one another. We once again confirmed clinical and biochemical parameters most strongly correlated statistically with apoE plasma levels were also independent predictors of apoE concentration in type 2 diabetes, and that these predictors accounted for up to 29% of a diabetic’s circulating apoE level. Importantly, age was found to be a significant independent predictor in multi-variable regression analysis, albeit not a univariate predictor, with this finding being consistent with other studies on non- diabetic populations. Furthermore, we detected significant statistical interactions between at least some of the covariates, confirming that complex interplay exists between the predictors to influence circulating apoE levels. In Chapter 5 and 6, we assessed the risk of adverse cardiovascular outcomes and diabetic nephropathy in the FIELD cohort in relation to their baseline apoE plasma concentration. We confirmed that circulating apoE concentration was not a direct predictor of adverse cardiovascular outcomes or diabetic renal disease. We proposed that apoE is, rather, a composite surrogate biomarker for metabolic syndrome and an adverse cardiovascular body- type. Finally, in Chapter 7, we compared the plasma apoE concentration profiles in male and female diabetics of the FIELD cohort, based on earlier finding that gender was a strong independent predictor. Female diabetics had higher mean apoE levels than diabetic man. We identified a number of other clinical and biochemical parameters that interacted significantly with gender to influence apoE levels in both genders, which included age, smoking, diabetic nephropathy, ApoCIII, triglyceride, total bilirubin and a number of medications commonly prescribed in type 2 diabetes. The aim of this thesis is to provide further insight to the controversial field of apoE and cardiovascular disease. We sought to add to the current evidence our findings in a population which has arguably the highest risk of atherosclerosis. In the context of recent conflicting observations from large population-based study, we demonstrated comprehensively that circulating apoE concentration is not a direct biomarker for cardiovascular diseases or diabetic nephropathy. On the other hand, we established that plasma ApoE is a readily measurable surrogate marker of metabolic syndrome and adverse cardiovascular phenotype. Traditionally, metabolic syndrome is a clinical diagnosis based on a number of diagnostic features that may not be easily quantified. Plasma apoE level thus serve, potentially, as an objective composite score of metabolic dysfunction. Early identification of at-risk individuals enables aggressive preventative therapy against cardiovascular complications. As such, we hope that this thesis will provide impetus for further research into the utility of apoE plasma concentration as a screening and diagnostic tool for metabolic syndrome and also, potentially, an accessible therapeutic target for this condition.
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ROSSI, K. B. „Participação da Apolipoproteína-e na Atividade Microbicida in Vitro Contra o Mycobacterium Tuberculosis“. Universidade Federal do Espírito Santo, 2014. http://repositorio.ufes.br/handle/10/4582.
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Previous issue date: 2014-08-29A parede celular de Mycobacterium tuberculosis (Mtb) é constituída por 60% de lipídios, impedindo a passagem de uma grande quantidade de substâncias, além de desempenhar um importante papel na munopatogênese. A apresentação desses antígenos aos linfócitos se dá por meio de moléculas do tipo CD1. Por sua vez a Apolipoproteína-E (ApoE), glicoproteína amplamente distribuída nos tecidos, pode facilitar a apresentação de lipídios pelo CD1. A ApoE possui três principais alelos ApoE- 2, 3 e 4, que codificam três isoformas de proteínas, tipos 2, 3 e 4, que possuem diferentes estruturas e funções. A presença de determinadas isoformas da ApoE está associada a doenças infecciosas, como herpes labial, dano hepático severo causado pelo vírus da hepatite C, diarréia infantil e tuberculose pulmonar. Neste contexto, avaliamos a participação da ApoE na atividade microbicida in vitro frente ao Mtb. Para tanto, foram arrolados 13 indivíduos PPD-, 17 indivíduos PPD+ e 4 indivíduos com tuberculose pulmonar ativa. O uso de plasma humano depletado de ApoE nos experimentos de atividade microbicida in vitro mostraram um aumento significante (p=0,02) no número de micobactérias (431.5 ± 81.92 UFC) quando comparado ao grupo controle (313.0 ± 74.61 UFC). Esses resultados foram confirmados por um modelo experimental utilizando esplenócitos de camundongos de camundongos C57BL/6 (815.9 ± 76.32 UFC) e animais APOE nocaute (1133 ± 86.85 UFC) (p= 0.021). Quanto à produção de IL-10, no grupo PPD+, observamos que o grupo com depleção de ApoE (866.7 ± 447.8) apresentou uma produção menor desta citocina com relação ao controle infectado (1089 ± 481.3) (p=0,023). Já em relação ao IFN-, em ambos os grupos observou-se, após 72 horas, uma tendência à diminuição da produção dessa citocina no grupo com depleção, com relação ao grupo controle. Esses dados sugerem que a ApoE tem papel distinto na ativação da resposta imune e sua ausência pode prejudicar a resposta imune frente à tuberculose.
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Stening, Eva. „The Influence of APOE ε4 on the Hippocampus and Hippocampus-Dependent Memory“. Doctoral thesis, Uppsala universitet, Institutionen för psykologi, 2016. http://urn.kb.se/resolve?urn=urn:nbn:se:uu:diva-302855.
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APOE ε4 is the major genetic risk factor for Alzheimer’s disease, a dementia characterized by memory impairment and hippocampal atrophy. While associated with episodic impairment and reduced hippocampal volume in healthy aging, APOE ε4 has been related to increased episodic memory performance in young adults. The effect of APOE ε4 on hippocampal volume in young age is uncertain, with studies showing comparable or smaller volumes in ε4 carriers. This thesis aims to further explore the effects of APOE ε4 on episodic memory and hippocampal volume in young adults. In addition to episodic memory, spatial memory will also be assessed, as both these memory types are hippocampus-dependent. Furthermore, potential modulating effects of sex are assessed, as sex differences has been found in relation to APOE-related pathology, episodic and spatial memory and hippocampal volume. Study I examined the effects of APOE ε4 on episodic and spatial memory and hippocampal volume in young adults. Hippocampal volume was assessed by manual tracing of the hippocampal head, body and tail. Study II considered whole-brain structural covariance patterns of the anterior and posterior hippocampus. Furthermore, the association between these patterns and episodic and spatial memory performance was assessed. Study III investigated the effects of APOE ε4 on episodic and spatial memory and hippocampal volume in three different age groups. This was done in order to further explore the different effects of APOE ε4 on cognition and hippocampal volume seen in young and older age. In summary, APOE ε4 was positively associated with spatial function and episodic memory in young adults. Although there were no effects of APOE ε4 on hippocampal volume, structural covariance patterns of the anterior and posterior hippocampus differed as a function of APOE ε4 and sex. Thus, structural covariance may provide an early measure of APOE ε4-related effects on brain structure. Moreover, sex was found to modulate the effects of APOE ε4 to the disadvantage of women. This was seen in both age-related hippocampal volume effects and in structural covariance patterns in young adults, as well as in spatial memory performance across age groups.
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Elam, Kit. „MEMORY AND DEFAULT NETWORK ACTIVATION AS A FUNCTION OF APOE GENOTYPE“. OpenSIUC, 2010. https://opensiuc.lib.siu.edu/dissertations/204.
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The main purpose of this dissertation project was to assess the behavioral and neural correlates of Episodic Memory as a function of the APOE genotype in a healthy young adult sample. To accomplish this, 98 subjects completed behavioral tasks assessing visual memory, working memory, episodic memory, and attention. Subjects also completed questionnaires evaluating IQ, years of education, drug use, personality, and emotional traits. These subjects were also genotyped for the APOE gene, resulting in 29 APOE-ε4 carriers (subjects who had at least one ε4 allele) and 69 Non APOE-ε4 carriers (having no ε4 alleles). No differences were found between genotypic groups on any demographic characteristics, behavioral measures, or personality traits. From this larger pool of 98 subjects, a subset of 22 subjects (10 APOE-ε4, 12 Non APOE-ε4) completed additional behavioral tasks while undergoing functional magnetic resonance imaging. While being scanned, subjects were asked to learn word pairs during an encoding phase, make metamemory evaluations on their ability to later remember each word pair during a judgment of learning (JOL) task, and try to discriminate between original and recombined word pairs during a final recognition phase. Interspersed between these tasks was a rest task meant to elicit activity within the Default Network. No differences in memory or metamemory performance were found on the behavioral tasks administered during imaging based on genotype. In contrast, marked differences in brain activation were found between APOE-ε4 carriers and Non APOE-ε4 carriers across the various imaging tasks. During encoding, APOE-ε4 carriers were found to have greater activation than Non APOE-ε4 carriers in the dorsal anterior portion of the left superior temporal gyrus, cingulate gyrus, and anterior middle frontal gyrus. This same pattern - greater APOE-ε4 carrier activation as compared to Non APOE-ε4 carriers - was present in the parahippocampal gyrus and posterior middle temporal gyrus during the judgment of learning metamemory task. During the recognition task, greater activation was found for Non APOE-ε4 carriers versus APOE-ε4 carriers in the left parahippocampal gyrus, SPL, and right anterior superior frontal gyrus. During the rest task, greater activation was seen in APOE-ε4 carriers versus Non APOE-ε4 carriers in the left inferior frontal gyrus, whereas the converse comparison resulted in medial anterior cingulate activation. The lack of behavioral differences suggests that in a healthy young adult sample, as was used in the present study, there are not yet detectable behavioral differences as a function of APOE genotype. The greater neural activity seen in APOE-ε4 carriers during the encoding and judgment of learning tasks is likely to reflect neural compensation: young adult APOE-ε4 carriers compensate for declines in cognitive efficiency with greater neural activity such that this greater neural activity improves behavioral performance, particularly in memory domains (Buckner, Andrews-Hanna, & Schacter, 2008; Han & Bondi, 2008; Levy et al., 2004; Trivedi et al., 2008). The relatively lower levels of activation in APOE-ε4 carriers during the recognition task may reflect stronger memory traces for studied items as a result of greater frontal and medial temporal lobe activity during the encoding and judgment of learning tasks in the APOE-ε4 carriers (Kirwan, Wixted, & Squire, 2008; Mondadoori et al., 2007; Squire, Wixted, & Clark, 2007). In the present sample, a lack of behavioral differences accompanied by neural disparity may signal the precursors of Alzheimer's disease, highlighting the progressive deteriorating influence of the APOE-ε4 allele. The aberrant pattern of default network activity seen in APOE-ε4 carriers underlies this influence as this genotype is proposed to preferentially contribute to the causes of Alzheimer's disease in areas common to the Default Network and Episodic Memory (Buckner et al., 2008). The present results strengthen previous findings illustrating a connection between the brain activity underlying memory processes, the default network, and the APOE genotype.
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Damy, Sueli Blanes. „Associação entre infecção experimental por Mycoplasma pneumoniae e/ou Chlamydophila (Chlamydia) pneumoniae e a intensidade das lesões ateroscleróticas da aorta, em camundongos C57BL/6 apoE KO, com ênfase na diferença entre os sexos“. Universidade de São Paulo, 2006. http://www.teses.usp.br/teses/disponiveis/10/10133/tde-16042007-121022/.
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Os mecanismos pelos quais os agentes infecciosos, independentes ou não de meio ambiente permissivo, podem promover a aterogênese e as manifestações clínicas não estão completamente esclarecidos. Apesar das numerosas publicações demonstrando a presença de antígenos ou DNA de agentes infecciosos nas placas de ateroma, a questão se o agente infeccioso pode iniciar o processo aterosclerótico ou agravá-lo permanece sem resposta, possibilitando o aprofundamento das pesquisas neste assunto. Desta forma, este trabalho tem como objetivo estudar se a infecção experimental, por C.pneumoniae e/ou M.pneumoniae, em camundongos C57BL/6 apoE KO induziria ou afetaria a intensidade e a característica de vulnerabilidade da placa ateromatosa, de acordo com o sexo e/ou a dieta rica em colesterol. Métodos: um grupo de camundongos recebeu dieta enriquecida com 1% de colesterol (hiperlipidêmica), e o outro ração com formulação adequada para espécie (normolipidêmica), desde os dois meses de idade. Aos 8 meses de idade foram subdivididos, inoculados com 106 UFI de C.pneumoniae e/ou 106 UFC de M.pneumoniae, por via intraperitoneal, reinoculados um mês após e sacrificados aos 10 meses de idade. Para análise histopatológica secções transversais das aortas torácicas foram processadas para emblocamento em parafina, cortadas com 5 µm de espessura e coradas pelas técnicas de hematoxilina-eosina e tricrômico de Masson. As medianas das variáveis: altura da placa, área da placa, área de gordura da placa, área da artéria, área da luz e porcentagem de obstrução da luz da artéria dos diferentes grupos foram submetidas ao teste de Mann Whitney, com o nível de rejeição de 5%. Resultados: a infecção por C.pneumoniae e/ou M.pneumoniae causou agravamento da aterosclerose tanto em camundongos C57BL/6 apoE KO machos quanto em fêmeas. No entanto, as fêmeas infectadas somente com M.pneumoniae evoluíram com placas mais instáveis, representadas por maior remodelamento positivo. A co-infecção por C.pneumoniae e M.pneumoniae induziu placas mais estáveis, ou seja, com menor conteúdo de gordura e sem remodelamento, tanto nos machos quanto nas fêmeas. A introdução de dieta rica em colesterol levou ao não desenvolvimento de remodelamento positivo do vaso nas fêmeas infectadas por M.pneumoniae, mas sim nas co-infectadas por C.pneumoniae e M.pneumoniae que apresentaram placas mais instáveis, por serem mais volumosas e com maior conteúdo de gordura. Nos machos houve desenvolvimento de placas mais gordurosas nos infectados por C.pneumoniae. Conclusão: A infecção por C.pneumoniae e/ou M.pneumoniae em camundongos C57BL/6 apoE KO levou ao desenvolvimento ou agravamento de placas de aterosclerose, com diferenças em relação a intensidade e padrões de vulnerabilidade de acordo com o sexo versus o tipo de agente infecciosos. Os subgrupos infectados de fêmeas apresentaram maior agravamento da aterosclerose do que os machos. A dieta rica em colesterol agravou a intensidade da aterosclerose e mudou os padrões de vulnerabilidade dos subgrupos infectados.Independent of the presence or not a favorable ambient, mechanisms by which infectious agents may boost atherogenesis and clinical aspects are not fully elucidated. In spite of many demonstrations of infeccious agent antigens or DNA, the question if the infection may iniciate or aggravate the atherosclerotic process remains unanswered, requiring further studies. Therefore, the present work studies if the experimental infection of C57BL/6 apoE KO mice by C. pneumoniae and/or M. pneumoniae induces or affects the intensity of atherosclerosis and its characteristics of plaque vulnerability, with regard to the gender and/or the cholesterolrich diet. Methods: a group of mice was fed with 1% cholesterol-enriched diet (hyperlipidemic), from two months of age; the other group received adequately formulated food for the species (normolipidemic). At eight months of age, the mice were subgrouped according to inoculation intra-peritoneally with 106 IFU of C. pneumoniae and/or 106 CFU of M. pneumoniae, and re-inoculation one month later. They were killed at ten months of age. Cross-sectional thoracic aorta fragments were studied in embedded in paraffin block sections stained Hematoxylin-eosin and Masson?s trichromic techniques. Differences in the median of the variables: plaque height, plaque area, area of fat plaque, luminal area and percent obstruction of the lumen searched using the Mann Whitney?s test, with a 5% level of rejection. Results: the infection by C. pneumoniae and/or M. pneumoniae worsened atherosclerosis in both males and females C57BL/6 apoE KO mice. However, the M. pneumoniae inoculated female group presented more unstable plaques represented by positive remodeling of the vessel. The co-infection by both bacteria induced more stable plaque represented by low fat content and absence of vessel remodeling, in both male and female mice. The introduction of cholesterol enriched diet led to lack of positive vessel remodeling in M.pneumoniae inoculated female group, but development of unstable plaques characterized by large plaque are with high content of fat, in co-infected ones. In male groups there was development of plaque with higher fat content in the subgroup inoculated with C.pneumoniae. Conclusion: Infection by M. pneumoniae and/or C. pneumoniae, in C57BL/6 apoE KO mice, led to development or aggravation of atherosclerotic plaques, with differences regarding intensity and pattern of vulnerability according to the gender versus type of infectious agents. The infected female groups presented more aggravation of atherosclerosis than male ones. Cholesterol enriched diet aggravated the intensity of atherosclerosis and changed the patterns of vulnerability of infected subgroups.
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DAL, MAGRO ROBERTA. „Enhanced brain targeting of ApoE-functionalized lipid nanoparticles“. Doctoral thesis, Università degli Studi di Milano-Bicocca, 2016. http://hdl.handle.net/10281/103191.
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The blood-brain barrier (BBB) plays an important role in maintaining the homeostasis of the central nervous system and in protecting the brain from potentially harmful endogenous and exogenous compounds. Nevertheless, it represents also the major obstacle for the diagnosis and therapy of brain diseases. One of the most promising strategies to overcome the limited BBB penetration of drugs and contrast agents is based on nanoparticles (NP). Lipid based NP, mainly liposomes (LIP) and solid lipid nanoparticles (SLN), have several advantages in terms of biocompatibility, non-immunogenicity, non-toxicity; they can be used as carrier systems and they have a prolonged circulation time in blood. Moreover, their surface can be easily modified with ligands which mediate a site-specific targeting. The aim of the present investigation is related to the evaluation of the ability of NP functionalized with Apolipoprotein-E (ApoE) or a peptide derived from ApoE (mApoE) to cross the BBB and reaching the brain parenchyma. The thesis is structured in three main chapters. In the first one, the intratracheal instillation (IT) has been investigated as an alternative, non-invasive delivery route to reach the brain. It has already been proven that LIP functionalized with phosphatidic acid (PA) and mApoE (mApoE-PA-LIP) and administered by intraperitoneal (IP) or intravenous (IV) injection, are able to cross the BBB in vivo. The results here obtained showed that mApoE-PA-LIP were able to cross the pulmonary epithelium ([14C]-PA permeability=6.5±2.0×10-6 cm/min) in vitro and to reach the brain (0.6 ug PA/g brain) in vivo. In the second chapter, the interaction of SLN covalently coupled with mApoE (SLN-mApoE) and brain capillary endothelial cells (hCMEC/D3) has been evaluated. SLN without surface-located peptide displayed less membrane accumulation and cellular uptake compared to SLN-mApoE. Moreover the presence of mApoE significantly enhanced SLN permeability across the BBB in vitro model ([14C]-DPPA permeability=5.7±0.3×10-5 cm/min, [3H]-CE permeability=6.9±0.4×10-5 cm/min). The in vivo biodistribution of SLN has been evaluated by means of fluorescent microscopy tomography system, and the here obtained results demonstrated that IT administration of SLN-mApoE significantly increased SLN-related fluorescence in the brain compared to IV and IP administrations. Finally, the third chapter focuses on an alternative strategy to functionalize the surface of SLN with ApoE by mimicking an artificial apolipoprotein-E mediated protein corona. Two isoforms of apolipoprotein-E were utilized to produce non-covalent functionalized SLN and their in vivo biodistribution after IV injection was assessed. Thirty minutes after injection, SLN+ApoE4 reached the brain thus distributing in the brain microvessels as well as in the brain parenchyma. These results suggest that the functionalization of both LIP and SLN with ApoE-derived peptide increases NP brain targeting and that IT instillation could be exploited as an alternative route for the administration of NP specifically designed for brain targeting. Moreover, the ApoE-mediated artificial protein corona effect could be an elegant alternative to increase SLN-BBB crossing.
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Martinic, Goran (Gary), of Western Sydney Hawkesbury University, of Science Technology and Environment College und School of Environment and Agriculture. „Cyclodextrins as potential human anti-atherosclerotic agents“. THESIS_CSTE_EAG_Martinic_G.xml, 2001. http://handle.uws.edu.au:8081/1959.7/129.
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Cyclodextrins (CDs) are naturally occurring cyclic oligosaccharides. Since it is believed that OxC blocks the removal of normal cholesterol from cells in the artery wall, it is possible that selective removal of OxC in the vessel wall in-vivo may prevent or reverse atherosclerosis.As a prelude to major studies, this research project was designed to answer two critical questions; 1/. What is the best route for delivery of CD. 2/. How do animals (apoE-/- mice) tolerate it. Pilot studies were established and results noted. These studies have provided valuable information in the apoE-/- mouse for subsequent studies to prevent or reverse atherosclerosis in this animal model.Master of Science (Hons)
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Hussain, Aseem. „Beneficial effects of estradiol are mediated through apoE /“. View online, 2008. http://repository.eiu.edu/theses/docs/32211131425346.pdf.
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Trachtenberg, Aaron J. „The effects of APOE genotype on brain function“. Thesis, University of Oxford, 2011. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.542982.
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Xie, Ting. „Interactions épistatiques et modifications épigénétiques pour la stratification moléculaire des maladies chroniques“. Thesis, Université de Lorraine, 2017. http://www.theses.fr/2017LORR0339/document.
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Les maladies chroniques, comme les maladies cardiovasculaires (MCV), la maladie d'Alzheimer (AD), la dépression et l'ostéoporose, sont les principales causes de mortalité dans le monde. L'identification de facteurs de risque communs à ces maladies pourrait contribuer à un vieillissement «sain» mieux surveillé en utilisant des stratégies personnalisées de prédiction des risques, de prévention précoce et de traitement adéquat, en tenant compte des comorbidités très souvent existantes. Dans cette thèse, 8 publications ont été développées. Dans un premier temps, j'ai résumé, dans un article de revue, les défis actuels et les opportunités de la pharmacogénomique des médicaments contre les maladies cardiovasculaires. J'ai participé à la formation d'un consortium international, le Consortium VEGF et j'ai participé à une étude qui a identifié des interactions épistasiques entre les polymorphismes qui régulent les niveaux de VEGF et la pression artérielle et les indices d'adiposité. J'ai également démontré qu’un marqueur génétique de VEGF, le rs4416670, était significativement associé à un risque accru de dépression. En outre, j'ai signalé deux interactions significatives entre les variantes liées au VEGF affectant la densité minérale osseuse du col fémoral chez les femmes ménopausées. J'ai également étudié deux marqueurs liés au métabolisme des lipides : l'apolipoprotéine E (APOE) et le «lipolysis-stimulated receptor» (LSR). J'ai trouvé que le variant LSR rs916147 peut interagir avec APOE d'une manière qui inverse l'effet protecteur de l'allèle ε2 de l'APOE sur les lipides sanguins, fournissant ainsi de nouvelles connaissances sur les mécanismes de l'hyperlipoprotéinémie de type III. Les interactions épistasiques entre ces deux gènes augmentent également le risque d’AD même en l'absence de l'allèle à risque, APOE ε4. Finalement, j'ai réalisé des études épigénetiques (EWAS) sur l'obésité centrale et les traits lipidiques chez des individus sains. Les résultats suggèrent qu'un CpG pourrait affecter le tour de taille à travers une voie de signalisation de l'insuline. En outre, deux CpGs ont été associées aux niveaux des triglycérides par des gènes liés aux maladies cardiaques génétiques (PRKAG2) et à l'inhibition de la signalisation Wnt / bêta-caténine impliquée dans le développement des MCV et d’AD (KREMEN2). En conclusion, dans cette thèse j’ai utilisé l'étude de l'épistasie et de l'épigénétique pour identifier des interrelations complexes entre VEGF, LSR, APOE et différentes maladies chroniques (MCV, AD, ostéoporose, dépression) proposant ainsi de nouveaux mécanismes et des dénominateurs communs de ces maladies qui devraient être utilisés comme biomarqueurs de médecine personnaliséeChronic diseases, like cardiovascular diseases (CVD), Alzheimer’s disease (AD), depression and osteoporosis, are major causes of mortality in the world. Identification of common to those diseases risk factors could help for a better-monitored ‘healthy’ aging, by promotion of personalised strategies for risk prediction, early prevention and adequate treatment, all taking into account the very often existing comorbidities. In this thesis, 8 publications have been developed. Initially, in a review paper, I have summarised the current challenges and opportunities of pharmacogenomics of CVD medications. I have participated in the formation of an international consortium, the VEGF Consortium, and I have participated in a study that identified significant epistatic interactions between polymorphisms that regulate the levels of VEGF and their effects on blood pressure and adiposity indexes. I have also demonstrated that one genetic marker of VEGF, rs4416670, was significantly associated with an increased risk for depression. Furthermore, I have reported two significant interactions between VEGF-related variants affecting the femoral neck bone mineral density in post-menopausal women. I have focused also on two markers linked with lipids metabolism: the apolipoprotein E (APOE) and the lipolysis-stimulated receptor (LSR). I have found that the LSR variant rs916147 can interact with APOE in a way that reverses the protective effect of the ε2 allele of APOE on blood lipids, thus providing new insights in the mechanisms underlying type III hyperlipoproteinemia. Epistatic interactions between these two genes have also been shown to increase the risk of AD, even in the absence of the known risk allele APOE ε4. Finally, I have performed epigenome-wide association studies (EWAS) on central obesity and blood lipid traits in healthy individuals. The results suggest that one methylation probe could affect waist circumference through an insulin-signaling pathway. Furthermore, two methylations probes were associated with triglycerides levels through genes linked with genetic heart diseases (PRKAG2) and with inhibition of the Wnt/beta-catenin signaling that is involved in CVD and AD development (KREMEN2). In conclusion, this thesis used the study of epistasis and epigenetics and identified complex inter-relationships between VEGF, LSR, APOE and different chronic diseases (CVD, AD, osteoporosis, depression) and novel mechanisms that link disease development with DNA methylation, thus demonstrating their role as common denominators of diseases that can be used as valuable markers in personalised medicine
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Nielsen, Henrietta M., Kewei Chen, Wendy Lee, Yinghua Chen, Robert J. Bauer, Eric Reiman, Richard Caselli und Guojun Bu. „Peripheral apoE isoform levels in cognitively normal APOE ε3/ε4 individuals are associated with regional gray matter volume and cerebral glucose metabolism“. BIOMED CENTRAL LTD, 2017. http://hdl.handle.net/10150/622812.
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Background: Carriers of the APOE epsilon 4 allele are at increased risk of developing Alzheimer's disease (AD), and have been shown to have reduced cerebral metabolic rate of glucose (CMRgl) in the same brain areas frequently affected in AD. These individuals also exhibit reduced plasma levels of apolipoprotein E (apoE) attributed to a specific decrease in the apoE4 isoform as determined by quantification of individual apoE isoforms in APOE epsilon 4 heterozygotes. Whether low plasma apoE levels are associated with structural and functional brain measurements and cognitive performance remains to be investigated. Methods: Using quantitative mass spectrometry we quantified the plasma levels of total apoE and the individual apoE3 and apoE4 isoforms in 128 cognitively normal APOE epsilon 3/epsilon 4 individuals included in the Arizona APOE cohort. All included individuals had undergone extensive neuropsychological testing and 25 had in addition undergone FDG-PET and MRI to determine CMRgl and regional gray matter volume (GMV). Results: Our results demonstrated higher apoE4 levels in females versus males and an age-dependent increase in the apoE3 isoform levels in females only. Importantly, a higher relative ratio of apoE4 over apoE3 was associated with GMV loss in the right posterior cingulate and with reduced CMRgl bilaterally in the anterior cingulate and in the right hippocampal area. Additional exploratory analysis revealed several negative associations between total plasma apoE, individual apoE isoform levels, GMV and CMRgl predominantly in the frontal, occipital and temporal areas. Finally, our results indicated only weak associations between apoE plasma levels and cognitive performance which further appear to be affected by sex. Conclusions: Our study proposes a sex-dependent and age-dependent variation in plasma apoE isoform levels and concludes that peripheral apoE levels are associated with GMV, CMRgl and possibly cognitive performance in cognitively healthy individuals with a genetic predisposition to AD.
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GARCIA, Analia Nusya de Medeiros. „Polimorfismos dos genes CYP 46 e APOE e declínio cognitivo em idosos residentes no distrito de Fernando de Noronha-PE“. Universidade Federal de Pernambuco, 2011. https://repositorio.ufpe.br/handle/123456789/8317.
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Previous issue date: 2011O Declínio Cognitivo Leve (DCL) é um estado mental considerado a zona de transição entre o envelhecimento normal e a fase mais inicial de demência, sendo uma fase importante para a precocidade diagnóstica. Nos últimos anos, pesquisas estão sendo desenvolvidas na busca de marcadores genéticos para esta zona de pré-demência, como os polimorfismos dos genes da apolipoproteína E (APOE) representada por 3 alelos (E2, E3, E4) e do colesterol 24S-hidroxilase (CYP46) com alelos T e C. Indivíduos portadores do APOE E4 tem fator de risco quatro vezes maior de desenvolver a Demência de Alzheimer e dez vezes mais probabilidade se tiver associado os polimorfismos dos genes APOE e CYP46. O objetivo deste estudo foi investigar a possível associação entre o polimorfismo dos genes CYP46(T/C), APOE E4 e a presença de DCL na população idosa do Distrito de Fernando de Noronha, totalizando uma seleção de 52 indivíduos. A avaliação clínica foi realizada através de exame físico, funcional e mental. Foram aplicados testes neuropsiquiátricos (Mini Exame do Estado Mental, Teste de Fluência Verbal, Teste do Relógio) e a identificação do genótipo dos polimorfismos do APOE e CYP46 pelo método de PCR-RFLP. Como resultados observou-se que 87% da amostra apresentou declínio cognitivo leve. No Mini Exame do Estado Mental, Teste de Fluência Verbal e Teste do Relógio foi observado declínio cognitivo em 42,8%, 31,9% e 53,2% respectivamente. Foi observada uma frequência alélica de 10% para o alelo E4. Não foi observada associação entre APOE E4 e declínio cognitivo. Os alelos T (p = 0,628) e C (p = 0,2076) do gene Cyp46 não estão associadas ao DCL na população estudada. Não foi observada associação (p = 0,4286), quando analisado o sinergismo entre o polimorfismo dos genes Cyp46(T/C) e APOE E4 no desenvolvimento do DCL. Nesta população, os resultados sugerem que os polimorfismos dos genes Cyp46(T/C) e APOE E4 não estão associados ao DCL
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Coppens, Ryan Patrick. „ApoE4 Genotype as a Moderator of Brain Responses to Target Stimuli Prior and Subsequent to Smoking Abstinence“. OpenSIUC, 2017. https://opensiuc.lib.siu.edu/dissertations/1494.
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A growing body of research is targeted towards characterizing and explaining nicotine’s complex interactions with the ApoE E4 allele on brain responses underlying cognitive processes. However, when and how the ε4 allele modulates neuroelectric brain responses in the presence of nicotine versus nicotine abstinence in nicotine-dependent smokers is not well characterized. Being able to understand this modulation is potentially quite important given that recent research implies that, relative to non-ε4 carriers, young adult carriers of the ε4 allele exhibit greater cognitive benefits from the use of nicotine. In the present study, electroencephalography (EEG) and the oddball-related P3b event-related potential (ERP) were used to better characterize the potential moderating effects of ApoE on P3b ERP amplitude changes associated with overnight nicotine deprivation in dependent smokers. Results showed a significant interaction between ApoE genotype and nicotine use, as ε4 carriers, relative to noncarriers, demonstrated significantly greater decreases following overnight deprivation, relative to prequit baseline levels. Additionally, there was a main of effect of P3b ERP amplitude to target stimuli being greater in ε4 allele carriers than in noncarriers during nicotine use, but no main effect of APOE genotype during overnight nicotine deprivation. These results are consistent with findings that the ApoE genotype moderates the effects of nicotine and alters neuroelectric brain responses associated with selective attention to infrequent target stimuli.
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Ferguson, Chantal M. „Modulating ApoE with Tissue Specific siRNAs in Alzheimer’s Disease“. eScholarship@UMMS, 2021. https://escholarship.umassmed.edu/gsbs_diss/1132.
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Among many putative genetic risk variations reported to date, the ApoE4 allele remains the most common genetic risk factor for late-onset AD, and is associated with both an increase in incidence and a decrease in age of clinical onset. The majority of ApoE is produced in the: 1) central nervous system (CNS) by astrocytes to transport lipids between cells and modulate the inflammatory response; and 2) liver, where it facilitates lipid uptake into peripheral tissues via low-density lipoprotein (LDL) receptors. Consistent with its dual roles, genetic knockout of ApoE increases the risk for atherosclerosis, but it also dramatically improves AD phenotypes in mouse models.
Antisense oligonucleotide (ASO) based modulation of CNS ApoE has only marginal effects on AD phenotypes, suggesting that post-embryonic silencing of ApoE is not a viable therapeutic strategy. However, the recent development of novel CNS siRNA chemical structures enables widespread distribution and potent target silencing throughout the brain. Using this technology, we demonstrate that liver and brain ApoE pools are spatially and functionally distinct, and that complete silencing of brain, not liver, ApoE results in robust reduction of amyloid plaque formation, without impacting systemic cholesterol. Furthermore, RNAseq analysis shows minimal off target effects of the siRNAs and identifies immune modulation and metabolic alterations as potential mechanisms behind ApoE’s role in plaque formation and clearance.
Moving forward, these results build upon the rationale to modulate ApoE expression and provide the technology necessary to further evaluate the impact ApoE silencing in AD and other neurodegenerative diseases
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Sinclair, Lindsey Isla. „Molecular and life-course aspects of APOE in cognition“. Thesis, University of Bristol, 2016. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.701968.
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Dementia has a devastating effect on patients and those around them. Alzheimer's disease (AD) is the most common form of dementia. There is no cure and the prevalence may increase as much as fourfold by 2050. Variation in the APOE gene is the best-known genetic risk factor for AD. There is evidence to suggest that changes are evident in those with the high-risk Ɛ4 variant decades before AD develops. The exact nature of these changes, timing and their effect on brain structure and function is not clear. Another variant, the Ɛ2 variant seems to protect against AD but again the mechanism is unclear.
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Blanchard, Valentin. „Approches biochimique, épidémiologique et clinique du métabolisme intégré de la Lipoprotéine (a)“. Thesis, La Réunion, 2020. http://www.theses.fr/2020LARE0007.
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Une personne sur cinq dans la population générale présente des niveaux plasmatiques élevés en lipoprotéine (a) [Lp(a)], une lipoprotéine extrêmement athérogène qui ressemble aux LDL. Les études physiopathologiques, épidémiologiques, et génétiques démontrent que lorsque la concentration sanguine en Lp(a) dépasse 125 nmol/L, la survenue d’événements cardiovasculaires augmente très fortement. La différence structurale majeure entre Lp(a) et LDL est que la Lp(a) contient une protéine caractéristique supplémentaire, l’apo(a), de taille très variable car elle contient entre 1 et 40 répétitions du domaine Kringle IV2 (KIV2). La taille de l’apo(a) est inversement corrélée aux concentrations plasmatiques en Lp(a). Outre l’apo(a), l’apoE et PCSK9 sont les deux seules autres protéines circulantes connues pour moduler les taux de Lp(a). L’objet de mes travaux de thèse a été de déterminer comment la taille de l’apo(a), le polymorphisme de l’apoE et l’inhibition pharmacologique de PCSK9 régulent les niveaux de Lp(a). Nous avons d’abord développé une approche méthodologique originale de spectrométrie de masse pour doser les apolipoprotéines, déterminer leurs polymorphismes, et en évaluer les flux métaboliques. Nous avons également mis au point une technique de séparation résolutive des différentes isoformes de l’apo(a) sur gel d’agarose. Nous montrons par spectrométrie de masse que l’apoE présente sur les VLDL gouverne la production (synthèse/assemblage) de la Lp(a). Par ailleurs, nous avons établi que les patients hypercholestérolémiques familiaux porteurs de l’isoforme E2 de l’apoE présentent des concentrations de Lp(a) plus faibles comparativement aux porteurs des isoformes E3 et E4, ce qui leur confère un taux de récidive pour les événements vasculaires réduit. Enfin, nous avons démontré chez des patients à haut risque cardiovasculaire que la réponse à un traitement par inhibiteurs de PCSK9 en termes de réduction de la Lp(a), est proportionnelle à la taille de l’apo(a). Nous avons également observé que le traitement par aphérèse d’un patient présentant des niveaux très élevés en Lp(a), le protège contre une récidive d’infarctus du myocarde. L’ensemble de mes résultats nous a permis de déterminer les modalités physiologiques par lesquelles la taille de l’apo(a) et le polymorphisme de l’apoE modulent les niveaux circulants de cette lipoprotéine extrêmement athérogène. Les thérapies actuelles (inhibiteurs de PCSK9, aphérèse) restent cependant insuffisantes pour une prise en charge optimale des patients avec une Lp(a) élevéeOne in five individuals in the population displays elevated circulating levels of lipoprotein (a) [Lp(a)], a highly atherogenic lipoprotein resembling LDL. Pathophysiological, epidemiological and genetic studies demonstrate that circulating Lp(a) levels above 125 nmol/L are associated with a sharp increase in cardiovascular events rate.The major structural difference between Lp(a) and LDL is that Lp(a) contains a signature protein, apo(a), extremely polymorphic in size as it contains 1 to more than 40 Kringle IV2 (KIV2) domains. The size of apo(a) is inversely correlated with the circulating levels of Lp(a). Besides apo(a), apoE and PCSK9 are the only other plasma proteins known to modulate Lp(a) levels. The aims of my PhD project were to assess how the size of apo(a), the polymorphism of apoE and the pharmacological inhibition of PCSK9 govern Lp(a) plasma concentrations. First, we have developed a robust methodological approach to quantitatively assay apolipoproteins, assess their polymorphisms and evaluate their metabolic fluxes by mass spectrometry. In addition, we have set up a resolutive separation technique allowing the investigation of distinct apo(a) isoforms on agarose gels. We then showed using mass spectrometry that apoE specifically present on VLDL impacts on Lp(a) production, synthesis and/or assembly. In addition, we clearly established that familial hypercholesterolemic patients specifically carrying the apoE2 isoform display reduced Lp(a) plasma levels and are thereby less prone to recurrent cardiovascular events compared with apoE3 or E4 carriers. Finally, we demonstrate that the response to PCSK9 inhibitor treatments of patients at high cardiovascular risk in terms of Lp(a) lowering is proportional to the size of apo(a). We also observed that apheresis procedures performed on a patient with extreme Lp(a) plasma levels reduce his risk of undergoing recurrent myocardial infarction. Taken together, my PhD results allowed us to decipher the physiological modalities by which apo(a) size and apoE polymorphism modulate the circulating levels of this extremely atherogenic lipoprotein species. The therapies currently available (PCSK9 inhibitors, plasmapheresis) remain however clearly insufficient to treat patients with elevated Lp(a)
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Szostak, Justyna. „Activité physique et prévention de l'arthérosclérose : Mise en évidence de l’implication des PPAR (Peroxisome Prolife- raor-Activated Receptor) dans la cardioprotection induite par l’exercice physique soumis ou volontaire chez la souris ApoE-/- mice“. Thesis, Besançon, 2012. http://www.theses.fr/2012BESA3006/document.
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L‟athérosclérose est un processus inflammatoire chronique à l‟origine des accidents cardiovasculaires quiconstitue l‟une des premières causes de mortalité en France. L‟inflammation est le facteur essentiel dansl‟initiation, la progression et l'instabilité des lésions athéromateuses à l‟origine des accidents aigus. Lesdonnées récentes suggèrent que l‟activation des récepteurs nucléaires PPAR (Peroxysome-ProliferatorActivated Receptor) par des ligands pharmacologiques prévient le développement et la progression del‟athérosclérose et diminue de manière importante la mortalité cardiovasculaire. À côté de ces traitementspharmacologiques, l‟exercice physique prévient aussi la mortalité cardiovasculaire de manière significative.L‟objectif de notre premier travail a été d‟explorer les effets de l‟exercice physique de natation, sur le développementdes lésions athéromateuses d‟une part et d‟autre part, sur l‟expression des récepteurs nucléairesPPAR. Nos résultats montrent que l’exercice physique de natation diminue la progression del’athérosclérose et stimule l’expression des PPAR-γ vasculaires. De manière intéressante, lorsque lePPAR-γ est inhibé avec l'antagoniste BADGE, les effets antiathérogènes de l’exercice physique sontabolis.L‟hypertension est à l‟origine des complications graves telles que la rupture de plaque d‟athérosclérose.L‟objectif de notre deuxième travail a été d‟explorer l‟implication des PPAR dans la progression et la stabilitédes lésions athéromateuses chez des souris ApoE-/- hypercholestérolemiques et hypertendues (2K1C),soumises à des exercices physiques (volontaire ou imposé) ou traités avec le telmisartan, un antihypertenseur.Nos résultats montrent que l’exercice physique possède différents mécanismes protecteurs. Demanière similaire, l‟exercice physique favorise la stabilité de lésions athéromateuses de manière comparableau traitement pharmacologique. De plus, nos résultats montrent que les souris traitées avec l‟exerciceimposé ou le telmisartan présentent un mécanisme comparable qui permet de réduire significativementl‟expression des cytokines pro-inflammatoire et d‟activer les PPAR-γ vasculaires. L‟exercice volontairefavorise l‟expression des marqueurs des macrophages alternatifs Mβ et des cytokines anti-inflammatoires(CD 206, IL-1Ra). L‟exercice volontaire diminue significativement l‟extension des lésions athéromateuses demanière comparable au telmisartan. Ces résultats montrent que l’exercice physique volontaire etl’exercice physique imposé ont deux mécanismes d’actions distincts. De plus, la surexpression des M2en réponse à l‟exercice volontaire modifie la balance inflammatoire en faveur des Mβ. Ce renversement dela balance au profit des macrophages alternatifs M2 est significativement corrélé à la diminution dela progression des lésions athéromateuses.Les exercices imposé et volontaire possèdent des mécanismes d‟action distincts. L‟exercice soumis diminuel‟expression des cytokines pro-inflammatoires tandis que l‟exercice volontaire augmente l‟expression descytokines anti-inflammatoires et favorise un phénotype anti-inflammatoire des macrophages M2 quis‟accompagne d‟une réduction des lésions athéromateusesAtherosclerosis is a complex inflammatory process, leading cause of morbidity and mortality in France.Inflammation is essential in initiation, progression and atherosclerosis plaque destabilization leading to acutecardiovascular events. Recent studies suggest that pharmacological PPAR activation prevents ATH developpementand progression and decreased cardiovascular mortality. Compared to pharmacological treatment,physical exercise also significantly prevents cardiovascular mortality.The aim of the first study was to investigate the influence of physical exercise on ATS development andPPAR expression in arterial wall. Our results had shown that physical exercise decrease ATH progressionand increase PPAR-γ expression in arterial wall. Interestingly, PPAR-γ inhibition with BADGE, a PPAR-γantagonist abolishes these antiatherogenic effects. Hypertension increase ATH complication such as plaque rupture. The aim of the second study were to investigatePPAR-γ implication in progression and stabilization of ATH lesions in hypercholesterolemic and hypertensiveApoE-/- mice (2K1C) submitted to different exercises (voluntary wheel running and submitted treadmillrunning) or treated with telmisartan an anti-hypertensive drug. Our results shown that, physical exerciseprevents ATS cardiovascular events by several mechanisms. Similarly to telmisartan, physical exercisesstabilize ATH lesion. Moreover results shown that, submitted exercise and telmisartan have an comparablemechanism. In fact, they significantly decrease pro-inflammatory cytokines expression and in the same timeactivated PPAR-γ expression in arterial wall. Contrary to submitted exercise, voluntary exercises increasesexpression of anti-inflammatory cytokines IL-1ra and increase M2 marker CD206. These results suggestthat voluntary and submitted exercise have two different mechanism of action. Moreover, M2 surexpressionin response to voluntary exercise shift the inflammatory balance in favor to M2. Further, this change of balancein favor to M2, is significantly correlated to decrease of ATH progression. Voluntary exercises significantlydecreases ATH progression in the same levels like telmisartan treatment.Voluntary and submitted exercise has two different mechanisms, submitted exercise decrease proinflammatory
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Cieslak, Stephen Gerard. „The Effects of L-Cysteine on Alzheimer's Disease Pathology in APOE2, APOE3, and APOE4 Homozygous Mice“. BYU ScholarsArchive, 2016. https://scholarsarchive.byu.edu/etd/6585.
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The APOE gene is of profound importance regarding the onset of Alzheimer's disease (AD). From the small physical differences among the protein products of the isoforms of this gene arises a profound difference in their physiologies. For example, the APOE2 isoform confers resistance to AD, the APOE3 isoform confers neutral susceptibility to AD, and the APOE4 isoform confers proneness to AD. L-cysteine is an amino acid that has several anti-AD properties, among which are its ability to sequester iron and form glutathione – a powerful antioxidant – and therefore may be a promising potential dietary supplement for ameliorating AD pathology. In our experiment, we fed Mus musculus (mice) homozygous for APOE2, APOE3, and APOE4 either a control diet or a diet high in L-cysteine. Using Western blotting analysis, we quantified Amyloid β (Aβ), hyper-phosphorylated Tau (HP-Tau), and the three APOE proteins that we extracted from post-mortem brains of APOE2, APOE3, and APOE4 homozygous mice of 3-, 6-, 9-, and 12-month ages. We calculated a three-way ANOVA on a sample of 86 mice to examine the effect of age, genotype, and diet on protein quantities. We found that administration of L-cysteine trends towards lowering levels of Aβ in each cohort, but this effect is statistically insignificant. On the other hand, L-cysteine caused a significant decrease in APOE production with regard to diet [F(1,62) = 6.17, p=0.02], indicating that less APOE is produced due to the decrease in Aβ burden. Furthermore, administration of L-cysteine revealed no significant impact on or trends regarding HP-Tau deposition between diet types for each cohort. However, we observed that L-cysteine appeared to nullify the increasing trend in HP-Tau deposition between APOE2 and APOE4 cohorts. Thus, L-cysteine may be weakly affecting HP-Tau deposition via its ability to somewhat reduce Aβ burden and consequently prevent the shutdown of the proteosomes responsible for the degradation and clearance of HP-Tau. Taken together, these data suggest that L-cysteine should be considered as an intervention for AD pathology.
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Bouchareychas, Laura. „Implication des phagocytes mononuclées dans l'évolution de la plaque d'athérosclérose et relation avec l'homéostasie du cholestérol et des lipoprotéines“. Thesis, Paris 6, 2014. http://www.theses.fr/2014PA066282/document.
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L'athérosclérose est un processus physiopathologique chronique impliqué dans la majorité des maladies cardio-vasculaires. Le développement des lésions d'athérosclérose est caractérisé par l'accumulation de lipides extra et intracellulaires dans la paroi artérielle à l'origine d'une forte réponse inflammatoire impliquant notamment les macrophages. Les macrophages sont considérés comme des acteurs clés dans le développement des plaques d'athérosclérose. En effet, de par leur capacité à métaboliser le cholestérol (captation, stockage, efflux), à réguler l'inflammation et à phagocyter les cellules apoptotiques, ils exercent des fonctions pro et/ou anti-athèrogènes qui peuvent être modulées à des fins thérapeutiques. Dans cette perspective, nous avons évalué le pouvoir thérapeutique des " macrophages protégés de l'apoptose " sur la progression des lésions d'athérosclérose constituées. Nous avons démontré que l'augmentation de la survie des macrophages permet de ralentir la progression des lésions, de stabiliser les lésions et de diminuer la cholestérolémie. Ces effets athéro-protecteurs sont attribués à l'augmentation des cellules de Kupffer et des monocytes Ly-6Clow en partie par leur capacité à produire de l'apolipoprotéine E. Nous montrons également que les cellules de Kupffer participent à la clairance des lipoprotéines pro-athérogènes. L'augmentation du pool d'apoE ainsi que l'augmentation des cellules de Kupffer permettent de diminuer la cholestérolémie et ainsi de diminuer la progression des lésionsAtherosclerosis represents a chronic pathophysiological process implicated in the majority of cardiovascular diseases. The development of atherosclerotic lesions is characterized by an accumulation of extra and intracellular lipids in the arterial wall at the origin of a strong inflammatory response involving macrophages.Macrophages are considered key actors in the development of atherosclerotic plaques. Indeed, because of their ability to metabolize cholesterol (capture, storage, efflux), to regulate inflammation and to phagocyte apoptotic cells, they exert pro and/or anti-atherogenic functions that may be modulated therapeutically. In this context, we evaluated the therapeutic potential of macrophages protected against apoptosis, on the progression of established atherosclerotic lesions.We have demonstrated that increased macrophage survival can slow down the progression of established lesions, stabilize lesion and reduce cholesterol levels. These athero-protective effects are attributed to the increase in Kupffer cells and Ly-6Clow monocytes partly due to their ability to produce apolipoprotein E. We also show that Kupffer cells are involved in the clearance of pro-atherogenic lipoproteins. The increase in ApoE pool and in Kupffer cells reduces cholesterol levels and thus lesion progression
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McCorkindale, Andrew Neil. „Investigating the pathogenesis of Alzheimer’s disease with machine learning“. Thesis, The University of Sydney, 2022. https://hdl.handle.net/2123/29764.
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Alzheimer’s disease (AD) affects millions worldwide, but there are no effective treatments. AD is defined by the initial accumulation of amyloid plaques before the formation of neurofibrillary tangles of tau protein leads to neurodegeneration. Multiple clinical trials directed at amyloid have not shown clinical benefits. Further research into the mechanisms of AD is necessary to identify other potential drug targets. Transcriptomic analysis is a powerful approach for studying mechanisms, but the commonly used methods have limitations such as a vulnerability to outliers. Machine learning (ML) algorithms address some of these limitations yet have rarely been applied to AD RNA-sequencing data. Here we apply ML to bulk RNA-seq data from postmortem human brain tissue (Religious orders study and Memory and Aging Project, Mount Sinai Brain Bank) to investigate the mechanisms underlying AD pathology and cognitive decline. The transcripts associated with AD pathology were identified, with LTF predictive of an AD diagnosis and severity of amyloid pathology (validated experimentally). PRTN3 and ADAMTS2 (but not LTF) were the key transcripts associated with the rate of cognitive decline, while neurofibrillary tangles in the anterior cingulate cortex was the key neuropathology. Next, we used ML to find the overlapping pathways between our transcripts of interest and genes from AD genome-wide association studies. Interactions were identified including between LTF and TREM2 while other transcripts (EMP3, SWAP70, WWTR1, VGF) were associated with AD markers and multiple AD risk genes. Finally, given the effect size of APOE status on AD risk, a stratified analysis confirmed the significance of our target genes and anterior cingulate tau pathology in APOE4 carriers while also demonstrating distinct AD mechanisms in APOE4 carriers. Overall, this work has identified new potential therapeutic targets in AD and shown that APOE4 carriers and non-carriers may require targeted interventions.
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Haskett, Darren. „Progressive Alterations in Microstructural Organization and Biomechanical Response in the ApoE Mouse Model of Aneurysm and the Underlying Changes in Biochemistry“. Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/581126.
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Abdominal Aortic Aneurysm (AAA) is a complex disease that leads to a localized dilation of the infrarenal aorta that develops over years. Longitudinal information in humans has been difficult to obtain for this disease, therefore mouse models have become increasingly used to study the development of AAAs. The objective of this study was to determine any changes that occur in the biomechanical response and fiber microstructure in the apolipoprotein E difficient (ApoE-/-) angiotensin II (AngII) infused mouse model of aneurysm during disease progression, as well as determine some of the underlying changes in biochemistry, and demonstrate a novel method of reducing any pathogenic protease activity. Using a Microbiaxial Opto-Mechanical Device (MOD), ex vivo studies included adult aortas of ApoE-/- AngII infused mice excised and tested for mechanical response simultaneously imaged using two-photon microscopy to assess the microstructure at multiple time points. In vitro and ex vivo studies have shown changes in protease concentrations with the use of FRET based proteolytic beacons able to provide a non-destructive method to quantify protease activity measured against mechanical and microstructural changes. In vitro studies have demonstrated protease activity can be reduced using a molecule providing a positive feedback mechanism for protease inhibition and possibly provide a reduction in aneurysm progression.
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CAMPOREZ, D. „BIOMARCADORES de Diagnóstico Complementar na Doença de Alzheimer: Enfoque em Genes Que Participam da Formação da Placa Beta-amiloide,via do Folato e Geração de Estresse Oxidativo“. Universidade Federal do Espírito Santo, 2018. http://repositorio.ufes.br/handle/10/7147.
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Previous issue date: 2018-06-06A doença de Alzheimer (DA), é o tipo mais comum de demência relacionada a idade. É uma doença neurodegenerativa crônica, grave, progressiva, associada à perda de memória e cognição, que pode levar à morte. O maior fator de risco para o desenvolvimento da doença é a idade avançada, com uma complexa interação de fatores ambientais e genéticos que juntos podem aumentar a incidência da doença. Ainda que sua causa seja desconhecida, os fatores genéticos e o estresse oxidativo desempenham um papel importante na patogênese da DA. Neste estudo de associação nós investigamos se polimorfismos nos genes APOE (rs429358 e rs7412), FOXO3 (rs2802292), MTHFD1L (rs11754661), SERPINA3 (rs4934), SIRT1 (rs2273773) e SOD2 (rs4880) e fatores ambientais como: nível educacional, etnia e gênero estão associados com risco para a DA em uma amostra de 332 indivíduos idosos do sudeste brasileiro (109 pacientes com diagnóstico provável de DA e 223 controles - idosos saudáveis pareados por idade e gênero). Os polimorfismos genéticos foram analisados por meio da reação em cadeia da polimerase em tempo real (PCR-RT). Na nossa amostra o polimorfismo do gene APOE mostrou estar altamente associado com a doença, tendo os genótipos Ɛ4Ɛ4 e Ɛ3Ɛ3 demonstrado serem fator de risco e proteção, respectivamente. O genótipo GG do gene MTHFD1L mostrou estar associado com o aumento do risco de desenvolver a doença de Alzheimer. Já o genótipo GG e AG do gene SERPINA3 demonstraram ser fatores de proteção e risco, respectivamente. O genótipo TT e CT do gene SIRT1 também mostraram correlação com a doença. O nível educacional mostrou estar associado positivamente para os indivíduos do grupo controle que tiveram uma educação formal por mais de quatro anos. Os polimorfismos FOXO3 e SOD2 não demonstraram estar associados com a amostra e a doença em questão. Nossos resultados corroboram outras pesquisas, que demonstram que a etiologia da DA pode estar envolvida com alterações na via do folato, com o aumento do estresse oxidativo nas células do sistema nervoso central, além de apoiar a participação de proteínas formadoras das placas beta-amiloides na patologia da DA. Esses resultados podem ser úteis na busca de biomarcadores genéticos precoces capazes de identificar os sintomas do surgimento da demência, e fornecer novos dados para terapias no futuro, ajudando no entendimento deste distúrbio. Além disso, reforçam a hipótese de que diversos genes estão envolvidos na etiologia da DA, uma condição caracterizada também por instabilidade genômica e estresse oxidativo elevados, que podem contribuir significativamente para a degeneração neurológica observada nos pacientes.
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Li, Xiaojing. „Relating Brain Signal Complexity, Cognitive Performance and APOE Polymorphism – the Case of Young Healthy Adults“. Doctoral thesis, Humboldt-Universität zu Berlin, 2020. http://dx.doi.org/10.18452/21383.
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Das menschliche Gehirn ist ein komplexes System, dessen Komplexität von großer funktioneller Bedeutung. Das APOE ɛ4 Allel ist ein gut untersuchter genetischer Risiko-Faktor für die Ausbildung der Alzheimer’schen Demenz. Das wesentliche Ziel dieser Dissertation ist die Untersuchung der Verbindungen zwischen der Komplexität von Hirn-Signalen, APOE-Genotyp und kognitiver Leistung bei jungen gesunden Erwachsenen unter dem Gesichtspunkt individueller Unterschiede. Nachdem ich in der ersten Studie die Reliabilität der Residual Iteration Decomposition (RIDE), einer Methode zur Analyse von Gehirnsignalen, validiert hatte, im der zweiten Studie untersuchte ich, wie APOE-Genotypen mit der Komplexität des Gehirnsignals assoziiert sind, gemessen mit Multiscale Entropy (MSE) und kognitiven Fähigkeiten. Die zweite Studie zeigte, dass APOE ɛ4 mit einer höheren Entropie im Skala 1 bis 4 und einer niedrigeren Entropie im Skala 5 und darüber assoziiert ist; Darüber hinaus gibt es bei ε4-Trägern einen stärkeren Abfall der MSE von geschlossenen zu offenen Augen als bei Nicht-Trägern. Die ε4-Assoziation mit der kognitiven Leistung war komplex, aber im Grunde scheint ε4 mit einer schlechteren kognitiven Leistung bei Menschen mit niedrigerem Bildungsstand verbunden zu sein, während bei Hochschulabsolventen keine solche Assoziation auftrat. Anschließend verband die dritte Studie MSE mit einer anderen kognitiven Domäne - Gesichts- und Objekterkennungsfähigkeiten. Wir haben gezeigt, dass 1) eine erhöhte MSE bei geschlossenen Augen auf allen Skalen mit einer besseren kognitiven Leistung verbunden ist. 2) Eine erhöhte MSE in höheren Skalen war mit einer engeren Kopplung zwischen der RIDE-extrahierten Geschwindigkeit der Bewertung des Stimulus für einen einzelnen Versuch und der Reaktionszeit verbunden. Zusammenfassend, die Ergebnisse verbanden die Komplexität des Gehirnsignals, den APOE-Genotyp und das kognitive Verhalten bieten ein tieferes Verständnis der Gehirn-Verhaltens-Beziehungen.Human brain is a complex dynamical system, whose complexity could be highly functional and characterize cognitive abilities or mental disorders. The APOE ɛ4 allele is a well-known genetic risk factor for the development of Alzheimer’s Disease and cognitive decline in later human life. The main goal of this study is to investigate the bridges between brain signal complexity, APOE genotype and cognitive performance among young adults under the framework of individual difference. After validating the reliability of Residue Iteration decomposition (RIDE), a method for analysis brain signals in the first study, I investigated in the second study how individual differences in APOE genotypes are associated with brain signal complexity measured with Multiscale Entropy (MSE) and cognitive ability. The second study demonstrated that APOE ε4 is associated with higher entropy at scale 1-4 and lower entropy at scale 5 and above, especially at frontal scalp regions and in an eyes open condition; in addition, there’s a stronger drop in MSE from closed to open eyes condition among ε4 carriers than non-carriers. The ε4 association with cognitive performance was complex, but basically ε4 seems to be associated with worse cognitive performance among lower educated people, whereas no such association appeared among the higher educated. Afterwards, the third study connected MSE with a different cognitive domain – face and object cognition abilities. We showed that 1) increased MSE for a closed eyes condition at all scales is associated with better cognitive performance. 2) Increased MSE at higher scales (7 or 8) was associated with tighter coupling between RIDE-extracted single trial stimulus evaluation speed at the neural level and reaction time at the behavior level. To summarize, the results of my doctoral study connected brain signal complexity, APOE genotype and cognitive behavior among young healthy adults, providing a deeper understanding of brain-behavior relationships and – potentially – for early AD diagnosis when cognitive decline is not yet evident.
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Harris, Julian David. „Development of recombinant adeno-associated virus and second generation adenovirus vectors for the gene transfer of human apolipoprotein E (ApoE) in the APOE deficient mouse“. Thesis, Royal Holloway, University of London, 2005. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.420867.
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Filho, Sebastião Barreto de Brito. „Efeito da ingestão crônica de vinho sobre a homeostase glicêmica, lipídica e ponderal em camundongos ApoE Knockout“. Universidade do Estado do Rio de Janeiro, 2013. http://www.bdtd.uerj.br/tde_busca/arquivo.php?codArquivo=6770.
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Os benefícios à saúde relacionados ao consumo moderado de vinho incluem diferentes mecanismos, nos quais estão envolvidos tanto etanol quanto compostos fenólicos que são constituintes do mesmo. Com o objetivo de avaliar variações glicêmicas, ponderais e o depósito de triglicérides, colesterol e glicogênio hepáticos com uso regular de vinho tinto em camundongo ApoE Knockout, foram utilizados 60 camundongos machos adultos ApoE Knockout de peso médio de 30 gramas, distribuídos em três grupos de 20 animais: grupo vinho, grupo etanol e grupo água, os quais receberam 50 mL de vinho e 50 mL água, 6mL de etanol e 94mL de água e somente água respectivamente por quatro meses. Os parâmetros avaliados foram: variações glicêmicas, ponderais, acúmulo de triglicerídeos, colesterol e glicogênio hepáticos. O grupo vinho teve em relação a sua massa corporal uma área sob a curva maior que a dos outros dois grupos, mas com um percentual pequeno de aumento. A concentração do triglicerídeo hepático foi maior no grupo vinho 57% em relação ao grupo etanol, que foi 31,6% menor que o controle (p<0,01%). A concentração do colesterol hepático foi menor no grupo vinho (23,6%), assim como no grupo etanol (24,5%), (p<0,05%). A concentração do glicogênio hepático foi maior no grupo vinho (16%), porém não alcançando significado estatístico. A glicemia em jejum no dia da eutanásia foi maior no grupo etanol em relação aos demais grupos, porém não demonstrou diferença estatisticamente significante. Na análise histológica não foi observada diferença significativa entre os grupos, embora o peso médio em gramas nas gorduras, retroperitoneal e subcutâneas tenha sido aproximadamente duas vezes maior no grupo vinho. Concluiu-se que neste estudo o uso regular e crônico de vinho tinto aumentou triglicerídeo hepático, porém o álcool diminui o colesterol hepático. O aumento do triglicerídeo pode ser devido ao alto valor calórico do vinho ou alguma propriedade lipogênica desconhecida que levou ao aumento importante das gorduras retroperitoneais e subcutâneas em camundongos ApoE Knockout.The benefits to health related to regular consume of red wine includes different mechanisms in which are involved both ethanol and fenolics compounds of the wine. With the objective to evaluate glycemia, lipid profile and weight variations with regular use of red wine by ApoE Knockout mices, sixty adults ApoE Knockout mices weighing around 30g were distributed into 3 groups of 20 animals each: 1.Wine that received 50mL of wine plus 50mL of water, 2. Ethanol and Water groups, 6mL of ethanol plus 94mL of water and just water respectively for 4 months. We evaluate glycemia, weight variations and liver glycogen, triglycerides and cholesterol. The wine group had in relation to its mass body an area under the curve larger than the other two groups, but with a small percentage of increase. The concentration of liver triglycerides was higher in the wine 57% compared to ethanol group, which was 31.6% lower than the control (p<0.01%). The concentration of liver cholesterol was lower in wine (23.6%) and in ethanol group (24.5%) (p<0.05%). The liver glycogen concentration was higher in the wine (16%), although not reaching statistical significance. The fasting glicemia on the day of euthanasia was higher in the ethanol group compared to other groups, but not statistically significant difference. In histological analysis was not significantly different between groups, although the average weight in grams fat, retroperitoneal and subcutaneous was approximately two times higher in the wine group. It was concluded that in this study the regular and chronic use of red wine increased liver triglyceride, however alcohol decreases liver cholesterol. The increase of the triglyceride may be due to the high caloric value of wine or some lipogenic unknown property that led to an important increase in retroperitoneal and subcutaneous fat tissue in ApoE Knockout mice.
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Wadas, Theresa M. „Relationships among APOE Genotypes, Inflammatory Markers, and Risk Factors among African Americans with Ischemic Stroke“. Diss., The University of Arizona, 2015. http://hdl.handle.net/10150/556235.
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African Americans experience a disproportionate mortality, morbidity, and disability associated with ischemic stroke. Traditional risk factors offer some explanation for this finding, but novel risk factors have not been explored. APOE4 genotype, which is more prevalent in African Americans demonstrate a pro-inflammatory phenotype that may result in an exaggerated inflammatory response associated with ischemic stroke, resulting in worse outcomes. The purpose of this study was to examine relationships among APOE genotypes, inflammatory markers (CD11β, platelet leukocyte aggregates, IL-1β, IL-6, IL-8, and tissue necrosis factor alpha), the anti-inflammatory marker, IL-10, and risk factors (hypertension, diabetes type II, obesity, hyperlipidemia, and smoking) in African Americans at 3 days post stroke. Twenty five patients were enrolled with 12 patients in the APOE4 group and 13 patients in the non-APOE4 group. In the APOE4 group, 75% were male compared to 54% in the non-APOE4 group. The average age in the APOE4 group was 56.5 ± 9.0 compared to 66 ± 16.0 years in the non-APOE4 group. Females in the APOE4 group were younger with ages comparable to men. All participants had hypertension. Forty two percent of patients in the APOE4 group had two risk factors and 46% of patients in the non-APOE4 group had three risk factors. Major findings included 1) there were no statistical difference between inflammatory markers and APOE genotypes, and 2) the APOE4 carrier was not a predictor for overall inflammatory load among African Americans with ischemic stroke. The study was underpowered and small effect sizes were not sufficient to create statistical findings. This was the first study to examined APOE genotypes, inflammatory markers, and risk factors among African Americans with ischemic stroke. More studies are needed to not only investigate novel risk factors, but to also characterize inflammatory and genetic mechanisms with ischemic stroke and their associated outcomes among African Americans. Such studies may lead to primary and secondary prevention of ischemic stroke and reduce the health disparities associated with ischemic stroke among African Americans.
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Obregon, Tito Alexandra de. „APOE haplotypes in health, lessons from an Oklahoman African American population“. Oklahoma City : [s.n.], 2010.
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Naumann, Sandy. „Gen-Umweltinteraktion bei alkoholabhängigen Patienten am Beispiel von ApoE und Homocystein“. kostenfrei, 2009. http://d-nb.info/999863649/34.
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Young, Elizabeth. „HDL-apoE content regulates the cell surface displacement of hepatic lipase“. Thesis, University of Ottawa (Canada), 2009. http://hdl.handle.net/10393/28247.
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Human hepatic lipase (HL) is an interfacial enzyme that must be liberated from cell surface proteoglycans to hydrolyze lipoprotein triglyceride. HDL and apolipoprotein (apo)A-1 can displace HL from cell surface proteoglycans, much like heparin. HL displacement is inhibited by HDL-apoE content. Postprandial HDL is ∼2-fold better at displacing HL than fasting HDL, but only has about half the apoE content. Enriching native HDL with triglyceride decreases HDL-apoE content and increases HL displacement. In contrast, enriching synthetic HDL with apoE significantly inhibits HL displacement. HDL from fasted female normolipidemic subjects displaces HL ∼2-fold better than HDL from male subjects. HDL from female subjects also has significantly less apoE than HDL from males. Normolipidemic females have increased circulating HDL-bound HL. Hyperlipidemia has little effect on the HL displacement ability of HDL from men, while HDL from hypercholesterolemic females exhibits impaired HL displacement. HL displacement from liver HSPG therefore appears to be linked to interlipoprotein apoE exchange. Decreased HL displacement is associated with higher HDL-apoE levels and may impact vascular triglyceride hydrolysis.
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Jiang, Qingguang. „The role of ApoE and liver X receptors in Alzheimer's disease“. Cleveland, Ohio : Case Western Reserve University, 2008. http://rave.ohiolink.edu/etdc/view?acc%5Fnum=case1212161307.
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Karpe, Britta. „Effekt von Darbepoetin alfa auf die geschädigte Niere am ApoE(-/-)-Mausmodell“. kostenfrei, 2008. http://www.opus.ub.uni-erlangen.de/opus/volltexte/2008/1003/.
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Dumanis, Sonya Benjamina E. „Using APOE genotypes to identify new biomarkers for Alzheimer's disease risk“. Thesis, Georgetown University, 2013. http://pqdtopen.proquest.com/#viewpdf?dispub=3559756.
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Alzheimer's disease (AD), unlike the other leading causes of death, does not have a cure or an effective intervention strategy. The largest genetic risk factor for AD is APOE, with the ϵ4 allele increasing and the ϵ2 allele decreasing one's risk for the disease. It remains unclear how ApoE isoforms contribute to various AD-related pathological changes (e.g. amyloid plaques, synaptic and neuron loss). Here, we characterize the differences between the at risk group for AD (the ϵ4 carriers) and the not-at risk group (non-ϵ4 carriers), to determine what underlies APOE-related risk to AD.
To do this, we utilized APOE Targeted Replacement (TR) mice. These animals express the human APOE alleles (APOE-ϵ2, APOE-ϵ3, or APOE-ϵ4) under the mouse APOE promoter, and do not develop the plaques and tangles diagnostic of AD. We found that despite the lack of AD pathology, APOE-ϵ4 TR mice had alterations at the synapse. Specifically, APOE-ϵ4 TR mice have fewer dendritic spines at the post-synaptic terminal and simpler neuronal morphology compared to the other APOE genotypes. Pre-synaptically, we found that APOE-ϵ4 TR mice have reduced levels of glutaminase, increased levels of VGLUT1 and increased levels of glutamine (GLN). Taken together, these data suggest that the APOE-ϵ4 allele affects brain function well before AD pathogenesis occurs.
To begin addressing the mechanism by which APOE can impact dendritic spine morphology, we examined the role of the apoE receptor, ApoEr2. We found that increased surface levels of ApoEr2 promoted dendritic spine formation and that the ligand binding domain is necessary for us to observe these effects, suggesting that ApoEr2 may be involved in APOE related changes at the synapse.
To test whether there are CSF biomarkers of APOE-associated risk that could be followed in preventative therapeutic AD approaches, we examined levels of GLN in ante-mortem CSF samples from healthy controls. Consistent with our mouse studies, we found that APOE-ϵ4 carriers had higher levels of GLN compared to the other genotypes. These studies suggest that GLN may be a novel biomarker used to assess AD patients in their pre-clinical phases and as a therapeutic measure in preventative AD trials.
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Mathias, Daniel. „Auswirkungen niedrig dosierter ionisierender Strahlung auf inflammatorische Marker des ApoE-/- -Mäuse-Herzens“. Doctoral thesis, Universitätsbibliothek Leipzig, 2017. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-221195.
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Die Akutfolgen ionisierender Strahlung wurden in zahlreichen Studien gut untersucht, ein Zusammenhang zwischen Hochdosisbestrahlung und deterministischen Spätschäden wurde vielfach belegt. Über die Langzeitfolgen niedrig dosierter ionisierender Strahlung hingegen ist bislang weniger bekannt, obwohl epidemiologische Studien auf ein erhöhtes Risiko strahlenassoziierter Spätfolgen hinweisen, sogar bei sehr geringen Dosen. Ionisierende Strahlung bedingt dosis- und zeitabhängigen Veränderungen in zahlreichen Geweben. Mittlere bis hohe Strahlendosen führen unter anderem zur strahleninduzierten koronaren Herzkrankheit mit ihren vielfältigen Folgeerkrankungen.
Die vorliegende Studie beschäftigt sich mit den inflammatorischen, thrombotischen und fibrotischen Spätfolgen des murinen ApoE-/- -Herzens 3 bzw. 6 Monate nach Niedrig-Dosis-Bestrahlung. Dazu wurde die Expression ausgewählter Markerproteine an gefroren Herzschnitten und Plasmaproben mittels Immunfluoreszenzanalyse bzw. ELISA quantifiziert. Es konnte gezeigt werden, dass bereits sehr niedrige Bestrahlungsdosen (0,025 – 0,5 Gy) zu kompensatorischen Langzeiteffekten wie beispielsweise einer erhöhte Kapillardichte und Änderungen von Kollagen-IV und Thy-1-Expression führen. Dabei finden sich sowohl pro- als auch antiinflammatorische Effekte.
Aus den Erkenntnissen multipler inflammatorischer und thrombotischer Veränderungen nach Niedrigdosisbestrahlung ließen sich möglicherweise wichtige Rationalen der anti-inflammatorischen Strahlentherapie ableiten. Darüber hinaus könnte anhand systemischer Plasmamarker die individuelle Evaluation strahlenassoziierter Spätfolgen und Einleitung adäquater Interventionsstrategien ermöglicht werden. Ob die hier gezeigten Effekte nur in Patienten mit besonderem Risikoprofil, wie erhöhten Cholesterin-Spiegeln, oder auch metabolisch gesunden relevant sind, bleibt weiteren Untersuchungen vorbehalten.
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Larramona, Arcas Raquel. „ApoE4 pathology in Alzheimer’s disease from the perspective of organelle dysfunction in astrocytes“. Doctoral thesis, Universitat Autònoma de Barcelona, 2018. http://hdl.handle.net/10803/666659.
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La enfermedad de Alzheimer es la forma mas común de demencia en edades avanzadas, la cual afecta a 40 millones de personas alrededor del mundo. Es una enfermedad compleja que afecta no solo a neuronas, sino también a astrocitos. La Apolipoproteína E4 (ApoE4) ha sido descrita como el factor de riesgo genético más importante de la forma esporádica de la enfermedad y además, los astrocitos son los principales secretores de esta. La investigación sobre los mecanismos patogénicos causados por esta apolipoproteína está centrada en su rol extracelular. Por el contrario, nosotros analizamos las desregulaciones intracelulares que causa la ApoE4. En nuestro estudio, nos centramos en 2 principales procesos fisiológicos alterados en la enfermedad de Alzheimer: la señalización de calcio y las funciones mitocondriales. Utilizamos como modelo celular, astrocitos inmortalizados que expresan la forma humana ApoE3 (no asociada a ninguna patología) o la ApoE4. Utilizando indicadores de calcio fluorescentes y la técnica de Imagen de Calcio, determinamos que los astrocitos ApoE4 tienen alteraciones de la homeostasis de calcio, ya que presentan menores niveles de calcio intracelular basal pero mayores señales de calcio inducidas por estímulos purinérgicos en comparación con los astrocitos ApoE3. Una mayor actividad de la V-ATPasa y por lo tanto, una mayor entrada de calcio al lisosoma en los astrocitos ApoE4 explica estas alteraciones. Además, la salida de calcio lisosomal después de la activación de receptores purinérgicos es seguida por una mayor movilización de calcio del retículo endoplásmico en los astrocitos ApoE4 comparados con los ApoE3. La entrada de calcio extracelular es similar en ambos tipos celulares. Nuestros estudios también demuestran que la falta de lipoproteínas en el medio extracelular aumenta la magnitud de las respuestas de calcio inducidas por receptores purinérgicos en los astrocitos ApoE3, ya que la entrada de calcio extracelular amplifica la liberación del calcio lisosomal en estas células. Esta característica se pierde en las células ApoE4, en las cuales la magnitud de las respuestas de calcio no se ve afectada por las lipoproteínas extracelulares. Por otro lado, describimos alteraciones en las dinámicas mitocondriales determinadas por microscopia a tiempo real y el marcaje fluorescente de mitocondrias. En particular, las mitocondrias de células ApoE4 no realizan fisión después de la inhibición de la fosforilación oxidativa mitocondrial, mientras que las mitocondrias de los astrocitos ApoE3 si la realizan. Asimismo, los astrocitos ApoE4 tienen un incremento en la movilidad mitocondrial, una reducción de Parkina, proteína involucrada en la mitofagia y una reducción del ADN mitocondrial en comparación con los astrocitos ApoE3. En resumen, demostramos por primera vez que la ApoE4 endógena altera la señalización del calcio y las funciones mitocondriales en astrocitos. Teniendo en cuenta que la ApoE4 se expresa a lo largo de toda la vida de los individuos, estas alteraciones astrocíticas podrían aparecer en las primeras etapas de la enfermedad de Alzheimer. Para avanzar en la detección de estas primeras etapas de la patología, y ya que las proteínas del líquido cefalorraquídeo reflejan las funcionalidad de las células cerebrales, nosotros hemos identificado un grupo de proteínas astrocíticas presentes en este líquido relacionadas con la enfermedad de Alzheimer y que proponemos como firma funcional astrocítica. Esta firma esta compuesta de las proteínas S100B, ApoE, prostaglandina D2 sintetasa, cistatina 3, proteína integral de membrana 2C y clusterina. En general, la ApoE4 endógena altera las funciones de los astrocitos, un fenómeno que puede contribuir a la enfermedad de Alzheimer, además de a su detección a través de biomarcadores del líquido cefalorraquídeo.Alzheimer’s disease is the most common form of dementia in advanced ages affecting more than 40 million people around the world. It is a complex disease that affects not only neurons but also astrocytes. Apolipoprotein E4 (ApoE4) has been described as the most important genetic risk factor for the sporadic form of the disease and interestingly, astrocytes are its main secretors. The research about its pathogenic mechanisms has mainly focused on its extracellular role. On the contrary, we analysed the dysregulations that endogenous intracellular ApoE4 causes on astrocytes. We focused on 2 principal physiological processes altered in Alzheimer’s disease: calcium signalling and mitochondrial functions. As cellular model, we used immortalized astrocytes that express human ApoE3 (non-associated with any pathology) or ApoE4. Using fluorescent calcium indicators and the technique of Calcium Imaging, we determined that ApoE4 astrocytes have altered calcium homeostasis as they have lower basal intracellular calcium levels but higher purinergic-induced calcium signals compared to ApoE3 astrocytes. A high V-ATPase activity, and hence, higher lysosomal calcium uptake in ApoE4 astrocytes explains these alterations. Moreover, lysosomal calcium release after purinergic receptor activation is followed by higher endoplasmic reticulum (ER) calcium mobilization in ApoE4 than in ApoE3 astrocytes. Extracellular calcium entry is similar in both cell types. Our studies also demonstrated that the lack of lipoproteins in the extracellular medium upregulates the magnitude of purinergic-elicited calcium responses in ApoE3 astrocytes, as extracellular calcium entry amplifies lysosomal calcium release. This feature is missing in ApoE4 astrocytes being the magnitude of calcium responses unaffected by extracellular lipoproteins. On the other hand, we described alterations in mitochondrial dynamics determined by real-time microscopy and fluorescent mitochondria labelling. In particular, ApoE4 cell mitochondria do not perform fission after inhibition of mitochondrial oxidative phosphorylation whereas ApoE3 astrocyte mitochondria perform it. In addition, ApoE4 astrocytes have increased mitochondrial motility, reduction of Parkin, a protein involved in mitophagy, and reduction in mitochondrial DNA content compared to ApoE3 astrocytes. In summary, we demonstrated, for the first time, that endogenous ApoE4 alters calcium signalling and mitochondrial functions in astrocytes. Taking into account that ApoE is expressed throughout the life of individuals, these astrocytic alterations might appear in the early stages of the Alzheimer’s disease. In order to advance in the detection of such early phases of the pathology, and since cerebrospinal fluid proteins reflect the cellular function of brain cells, we next identified a group of astrocytic proteins present in the cerebrospinal fluid related to Alzheimer’s disease that we propose as a functional astrocytic signature for early stages of the disease. This signature is composed of S100B, ApoE, prostaglandin D2 synthetase, cystatin 3, integral membrane protein 2C and clusterin. Overall, endogenous ApoE4 alters astrocyte functions, a phenomenon that can contribute to Alzheimer’s disease, but also, to its detection through cerebrospinal fluid biomarkers.
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Dikotope, Sekgothe Abram. „Response of serum lipids to a fat meal in Black South African subjects with different apoe genotypes“. Thesis, University of Limpopo (Turfloop Campus), 2013. http://hdl.handle.net/10386/1059.
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Thesis (M.Sc. (Chemical Pathology)) --University of Limpopo, 2013Objectives The present study investigated how the serum lipids responded to a high-fat meal in black South African subjects with different APOE genotypes, a population that until recently was reported to be consuming a traditional diet of low fat and high carbohydrates. Methods Sixty students (males and females) of the University of Limpopo, Turfloop Campus were successfully genotyped using Restriction Fragment Length Polymorphism (RFLP) and grouped into four APOE genotype groups; ε2, ε2/ε4, ε3 and ε4. Only thirty-three subjects volunteered to participate in the oral fat-tolerance test (OFTT), but two were excluded for having abnormal total cholesterol (6.05 mmol/l) and LDL cholesterol (3.12 mmol/l) so only 31 subjects were left. The numbers per group were ε2=5, ε2/ε4=8, ε3=9 and ε4=9. After an overnight fast blood was drawn for measurements of baseline serum parameters. Subjects were administered a high fat meal 30 minutes after the baseline blood sample was drawn. Blood was drawn at intervals of 20, 40, 60, 120, 180, 240, 300 and 360 minutes for measurements of postprandial serum parameter levels. Serum parameters measured were triglyceride, total cholesterol, low density lipoprotein cholesterol, high density lipoprotein cholesterol, glucose and insulin. Results Mean levels of serum lipids at baseline in mmol/l were as follows; group 1[TG=0.69(0.55-0.81), TCHOL=3.10±0.29, HDL-C=1.12±0.32, LDLC= 1.67±0.28]; group 2 [TG=0.61(0.53-1.00), TCHOL=2.98±0.53, HDLC= 1.20±0.37, LDL-C=1.43±0.37]; group 3 [TG=0.67(0.28-0.86), TCHOL=2.96±0.54, HDL-C=1.22±0.30, LDL-C=1.46±0.47]; group 4 [TG=0.76(0.51-1.16), TCHOL=3.27±0.51, HDL-C=1.12±0.17, LDLC= 1.79±0.47]. There was no significant difference in the mean levels of baseline triglyceride, total cholesterol, low density lipoprotein cholesterol, and ix high density lipoprotein cholesterol between the APOE groups hence no significant difference in the response to a fatty meal. Conclusions There was no significant change in serum lipid concentrations after a fatty meal in individuals with different APOE genotypes in a population that consume a traditional diet of low fat and high carbohydrates. Due to the small sample size, the results should be interpreted with caution. A larger study is recommended to ascertain the role of APOE genotypes on serum lipid response to a fatty meal in Black South African population.
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Filippini, Nicola. „Brain structure, function and connectivity associated with APOE genotype : what changes when?“ Thesis, University of Oxford, 2010. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.525306.
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Farsian, Farnas [Verfasser], und Jörg Heeren [Akademischer Betreuer]. „ApoE Regulates Corticospinal Neuronal Survival Through ApoER2 / Farnas Farsian. Betreuer: Jörg Heeren“. Hamburg : Staats- und Universitätsbibliothek Hamburg, 2013. http://d-nb.info/1045024538/34.
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McColl, Barry. „Pathophysiology of cerebral ischaemia : effects of APOE genotype on outcome and endocytosis“. Thesis, University of Glasgow, 2004. http://theses.gla.ac.uk/4324/.
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Apolipoprotein E (apoE denotes protein: APOE denotes gene) is a lipid-transport protein abundantly expressed in the brain and strongly upregulated after acute brain injury. The APOE e4 allele is the major genetic risk factor for Alzheimer’s disease (AD) and has been associated with poorer outcome after various types of acute brain injury, including traumatic brain injury and subarachnoid haemorrhage. However, the role of APOE genotype in focal ischaemic stroke is less clear. The mechanism(s) by which APOE genotype may modulate outcome after acute brain injury are also unclear at present. Accordingly, the studies described in this thesis were undertaken to further address these issues. 1. Endocytic pathway alterations in human temporal lobe after global cerebral ischaemia and association with APOE genotype. 2. Characterisation and validation of the intraluminal filament model of focal cerebral ischaemia in C57BI/6J mice. 3. Association between APOE genotype and differences in outcome and endocytic pathway alterations after focal cerebral ischaemia in mice. 4. Adenovirus-mediated gene transfer of APOE e3 markedly reduces ischaemic brain damage after focal cerebral ischaemia in mice. The data presented in this thesis indicate an important role for APOE genotype in modulating outcome after ischaemic brain injury, further highlighting the favourable effects associated with the APOE e3 allele. APOE genotype-dependent alterations in the endocytic pathway are mechanisms which could contribute to differences in outcome. These data also highlight the neuroprotective effects achieved by manipulating apoE levels to promote the beneficial effects of apoE3. An apoE-based therapeutic strategy may be a potential approach for treatment of ischaemic brain injury in humans.
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Grace, Laurian Kerry. „The relationship between Alzheimer's disease, inflammation, the APOE genotype and neuronal integrity“. Doctoral thesis, University of Cape Town, 2013. http://hdl.handle.net/11427/3394.
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