APOE Ε4 Allele Research Articles

Association of polymorphism of apolipoprotein e gene with acute myocardial infarction and its short term clinical outcome

Abstract Background/Introduction Myocardial infarction (MI) is a multifactorial disease influenced by environmental and genetic factors. Apolipoprotein E (ApoE) is a protein incorporated into serum lipoproteins directing their catabolism via binding to receptors. It is a structural component of both chylomicrons and very low density lipoprotein (VLDL) remnants. ApoE is thought to play a central role in atherosclerosis by participating in overall plasma cholesterol homeostasis. In addition to other classical risk factors, positive family history of cardiovascular disease (CVD) has been found to be significantly and independently associated with MI in epidemiological studies (1). Besides traditional cardiovascular risk factors it is likely that additional genetic factors like ApoE gene polymorphism may interact with environmental factors to determine overall cardiovascular risk of an individual to develop MI. Purpose The purpose of our study was to determine the risk of association of variants of ApoE gene with Acute Myocardial Infarction. Moreover, we also wanted to study the impact of ApoE gene polymorphism in short term major adverse cardiac events (MACE) in patients with MI not willing for coronary intervention. Methods In this case control study a total of 200 consecutively admitted AMI patients admitted to the coronary care unit of our hospital were enrolled to the study along with 200 age and gender matched controls admitted during the same time period . ApoE gene polymorphism was detected by DNA extraction, DNA amplification by PCR in a DNA thermal cycler followed by restriction enzyme digestion(2). Chi square test was used to investigate the difference in genotype and allele frequencies in casend controls and also between observed and expected frequencies in the realm of Hardy-Weinberg equilibrium. Odds Ratio (OR) with 95 % confidence interval and p values were calculated while analysing the association of different genotypes of ApoE genetic polymorphism with the disease and MACE. Logistic regression analysis was carried out amongst the groups under consideration to find the unadjusted OR and adjusted OR of the genotypes in relation to the disease.p<0.05 was considered as significant Analysis was done in SPSS software. Results Besides the traditional risk factors Apo E4 allele (OR 2.298, CI 1.305-4.044 ) and Apo E3/E4 genotype (OR 2.116, CI 1.008-4.443, p=0.048) showed strong of association with the disease. There was a higher population of Apo E3/E4 genotypes and Apo E2/E3 genotypes with MACE events (25.6% and 28.6%), while the common ApoE3/E3 genotypes had a MACE event of 10.5 %. However, the difference was not significant (p=0.071, Χ 2 =8.63 df =4). Similarly, ApoE4 allele showed a non significantly higher MACE events (p=0.22, Χ 2 =3.01 df =4) Conclusion ApoE4 allele and ApoE3/E4 genotype are strongly and independently associated with AMI.RISK FACTORS AND RISK OF MIGenotype and MACE

Apolipoprotein E Induces Lipid Accumulation Through Dgat2 That Is Prevented with Time-Restricted Feeding in Drosophila

Background: Apolipoprotein E (ApoE) is the leading genetic risk factor for late-onset Alzheimer’s disease (AD), which is the leading cause of dementia worldwide. Most people have two ApoE-ε3 (ApoE3) alleles, while ApoE-ε2 (ApoE2) is protective from AD, and ApoE-ε4 (ApoE4) confers AD risk. How these alleles modulate AD risk is not clearly defined, and ApoE’s role in lipid metabolism is also not fully known. Lipid droplets increase in AD. However, how ApoE contributes to lipid accumulation in the brain remains unknown. Methods: Here, we use Drosophila to study the effects of ApoE alleles on lipid accumulation in the brain and muscle in a cell-autonomous and non-cell-autonomous manner. Results: We report that pan-neuronal expression of each ApoE allele induces lipid accumulation specifically in the brain, but not in the muscle. However, this was not the case when expressed with muscle-specific drivers. ApoE2- and ApoE3-induced lipid accumulation is dependent on the expression of Dgat2, a key regulator of triacylglycerol production, while ApoE4 still induces lipid accumulation even with knock-down of Dgat2. Additionally, we find that implementation of time-restricted feeding (TRF), a dietary intervention in which food access only occurs in the active period (day), prevents ApoE-induced lipid accumulation in the brain of flies and modulates lipid metabolism genes. Conclusions: Altogether, our results demonstrate that ApoE induces lipid accumulation in the brain, that ApoE4 is unique in causing lipid accumulation independent of Dgat2, and that TRF prevents ApoE-induced lipid accumulation. These results support the idea that lipid metabolism is critical in AD, and that TRF could be a promising therapeutic approach to prevent ApoE-associated dysfunction in lipid metabolism.

NF-κB in Alzheimer’s Disease: Friend or Foe? Opposite Functions in Neurons and Glial Cells

Alzheimer’s disease (AD) is a devasting neurodegenerative disease afflicting mainly glutamatergic neurons together with a massive neuroinflammation mediated by the transcription factor NF-κB. A 65%-plus increase in Alzheimer’s patients by 2050 might be a major threat to society. Hallmarks of AD are neurofibrillary tangles (NFTs) composed of hyperphosphorylated tau and amyloid beta (Aβ) plaques. Here, we review the potential involvement of transcription factor NF-κB by hereditary mutations of the tumor necrosis factor pathway in AD patients. One of the greatest genetic risk factors is APOE4. Recently, it was shown that the APOE4 allele functions as a null allele in human astrocytes not repressing NF-κB anymore. Moreover, NF-κB seems to be involved in the repair of DNA double-strand breaks during healthy learning and memory, a function blunted in AD. NF-κB could be a friend to healthy neurons by repressing apoptosis and necroptosis. But a loss of neuronal NF-κB and activation of glial NF-κB in AD makes it a foe of neuronal survival. Hopeful therapies include TNFR2 receptor bodies relieving the activation of glial NF-κB by TNFα.

Alzheimer's Disease: Exploring the Landscape of Cognitive Decline.

Alzheimer's disease (AD) is a progressive neurodegenerative disorder characterized by cognitive decline, memory loss, and impaired daily functioning. The pathology of AD is marked by the accumulation of amyloid beta plaques and tau protein tangles in the brain, along with neuroinflammation and synaptic dysfunction. Genetic factors, such as mutations in APP, PSEN1, and PSEN2 genes, as well as the APOE ε4 allele, contribute to increased risk of acquiring AD. Currently available treatments provide symptomatic relief but do not halt disease progression. Research efforts are focused on developing disease-modifying therapies that target the underlying pathological mechanisms of AD. Advances in identification and validation of reliable biomarkers for AD hold great promise for enhancing early diagnosis, monitoring disease progression, and assessing treatment response in clinical practice in effort to alleviate the burden of this devastating disease. In this paper, we analyze data from the CAS Content Collection to summarize the research progress in Alzheimer's disease. We examine the publication landscape in effort to provide insights into current knowledge advances and developments. We also review the most discussed and emerging concepts and assess the strategies to combat the disease. We explore the genetic risk factors, pharmacological targets, and comorbid diseases. Finally, we inspect clinical applications of products against AD with their development pipelines and efforts for drug repurposing. The objective of this review is to provide a broad overview of the evolving landscape of current knowledge regarding AD, to outline challenges, and to evaluate growth opportunities to further efforts in combating the disease.

IPSC-derived blood-brain barrier modeling reveals APOE isoform-dependent interactions with amyloid beta

BackgroundThree common isoforms of the apolipoprotein E (APOE) gene - APOE2, APOE3, and APOE4 - hold varying significance in Alzheimer’s Disease (AD) risk. The APOE4 allele is the strongest known genetic risk factor for late-onset Alzheimer’s Disease (AD), and its expression has been shown to correlate with increased central nervous system (CNS) amyloid deposition and accelerated neurodegeneration. Conversely, APOE2 is associated with reduced AD risk and lower CNS amyloid burden. Recent clinical data have suggested that increased blood-brain barrier (BBB) leakage is commonly observed among AD patients and APOE4 carriers. However, it remains unclear how different APOE isoforms may impact AD-related pathologies at the BBB.MethodsTo explore potential impacts of APOE genotypes on BBB properties and BBB interactions with amyloid beta, we differentiated isogenic human induced pluripotent stem cell (iPSC) lines with different APOE genotypes into both brain microvascular endothelial cell-like cells (BMEC-like cells) and brain pericyte-like cells. We then compared the effect of different APOE isoforms on BBB-related and AD-related phenotypes. Statistical significance was determined via ANOVA with Tukey’s post hoc testing as appropriate.ResultsIsogenic BMEC-like cells with different APOE genotypes had similar trans-endothelial electrical resistance, tight junction integrity and efflux transporter gene expression. However, recombinant APOE4 protein significantly impeded the “brain-to-blood” amyloid beta 1–40 (Aβ40) transport capabilities of BMEC-like cells, suggesting a role in diminished amyloid clearance. Conversely, APOE2 increased amyloid beta 1–42 (Aβ42) transport in the model. Furthermore, we demonstrated that APOE-mediated amyloid transport by BMEC-like cells is dependent on LRP1 and p-glycoprotein pathways, mirroring in vivo findings. Pericyte-like cells exhibited similar APOE secretion levels across genotypes, yet APOE4 pericyte-like cells showed heightened extracellular amyloid deposition, while APOE2 pericyte-like cells displayed the least amyloid deposition, an observation in line with vascular pathologies in AD patients.ConclusionsWhile APOE genotype did not directly impact general BMEC or pericyte properties, APOE4 exacerbated amyloid clearance and deposition at the model BBB. Conversely, APOE2 demonstrated a potentially protective role by increasing amyloid transport and decreasing deposition. Our findings highlight that iPSC-derived BBB models can potentially capture amyloid pathologies at the BBB, motivating further development of such in vitro models in AD modeling and drug development.

The Effects of APOE Alleles, Cognitive Activities, and Social Activities on Cognitive Decline in African Americans.

Older African Americans are among the fastest growing populations, yet are underrepresented in studies examining risk factors related to decline. The present study examines whether biological factors (APOE alleles) interact with behavioral factors including cognitive activities (e.g., reading, playing games) and social activities (e.g., participating in social groups) to predict cognitive decline in African Americans. 734 African American adults from the Minority Aging Research Study (MARS), aged 65 and older (with no known dementia at the time of enrollment) underwent annual cognitive testing for up to 10 years. At baseline, APOE status was determined and participants reported their frequency of participation in social and cognitive activities. Structural equation modelling was used to examine the effects of APOE, cognitive activities, and social activities on cognitive decline, and their interaction effects over a ten-year period. The number of APOE alleles had an effect on cognitive decline, such that a greater number of APOE4 alleles was associated with greater cognitive decline, whereas a greater number of APOE2 alleles was associated with less cognitive decline. Cognitive and social activities did not interact with APOE count to predict cognitive decline, however, APOE4 and social activities had additive, independent effects on cognitive decline. Results replicate prior findings linking APOE4 to cognitive decline and highlight the importance of APOE2 and social activities in delaying cognitive decline in African Americans.

Genetic Variants ε2 and ε4 of APOE Predict Mortality and Poor Outcome Independently in Spontaneous Intracerebral Hemorrhage Within the Chinese Han Population.

The heightened mortality and disability rates, coupled with restricted neurological recovery post intracerebral hemorrhage (ICH), have sparked considerable attention toward its treatment and results. Simultaneously, the influence of the APOE gene on ICH prognosis has been well-documented. This research aimed to explore the relationship between specific APOE alleles in the present cohort and the incidences of mortality, recurrence, and adverse prognosis, as determined by neurological function assessments in ICH patients. Data on patients diagnosed with ICH and hospitalized in the Department of Neurology at our institution from October 2021 to March 2022 were collected, including determining their APOE genotypes. A 1-year follow-up was conducted to evaluate mortality, ICH recurrence, and modified Rankin Scale (mRS) scores at 3 and 12 months. Poor prognosis was defined as an mRS score of ≥ 3. Initially, we analyzed the relationships between different APOE alleles and mortality, recurrence, and poor prognosis. Subsequently, we explored additional factors influencing each prognostic outcome and conducted multivariate analysis to identify independent risk factors. An analysis was conducted on 289 patients diagnosed with ICH. The presence of the ε2 allele was found to be a significant independent predictor for unfavorable outcomes at both 3 months (p = 0.022, OR = 2.138, 95% CI [2.041, 3.470]) and 1 year (p = 0.020, OR = 5.116, 95% CI [5.044, 5.307]). Moreover, the ε4 allele was established as an independent risk factor for ICH recurrence within 1 year (p = 0.025, OR = 2.326, 95% CI [1.163, 2.652]), as well as for mortality at 3 months (p = 0.037, OR = 4.250, 95% CI [4.068, 4.920]) and 1 year (p = 0.023, OR = 4.109, 95% CI [4.016, 4.739]). In conclusions, Both APOE ε2 and ε4 variants independently heighten mortality risk, recurrence, and poor prognosis after ICH. The substantial influence underscores the need for additional investigation into the impact of APOE genotype on ICH prognosis.

Pathways to Alzheimer's Disease: The Intersecting Roles of Clusterin and Apolipoprotein E in Amyloid-β Regulation and Neuronal Health.

One of the hallmarks of Alzheimer's disease (AD) is the deposition of amyloid-β (Aβ) within the extracellular spaces of the brain as plaques and along the blood vessels in the brain, a condition also known as cerebral amyloid angiopathy (CAA). Clusterin (CLU), or apolipoprotein J (APOJ), is a multifunctional glycoprotein that has a role in many physiological and neurological conditions, including AD. The apolipoprotein E (APOE) is a significant genetic factor in AD, and while the primary physiological role of APOE in the brain and peripheral tissues is to regulate lipid transport, it also participates in various other biological processes, having three basic human forms: APOE2, APOE3, and APOE4. Notably, the APOE4 allele substantially increases the risk of developing late-onset AD. The main purpose of this review is to examine the roles of CLU and APOE in AD pathogenesis in order to acquire a better understanding of AD pathogenesis from which to develop targeted therapeutic approaches.

B-236 New real-time PCR test for APOE genotyping in patients with Alzheimer’s disease before anti-amyloid therapy

Abstract Background In 2023, the US Food and Drug Administration approved LEQEMBI, a monoclonal antibody therapy targeting beta-amyloid plaques, for patients with early-stage Alzheimer’s disease (AD). However, anti-amyloid drug trials demonstrated an elevated risk for amyloid-related imaging abnormalities with cerebral edema (ARIA-E) in carriers of the AD risk allele apolipoprotein E epsilon 4 (APOE-ɛ4), especially in ɛ4/ɛ4 homozygous individuals [1-3]. Here, we report on the evaluation of a new real-time polymerase chain reaction (PCR) test for APOE genotyping. Methods The EURORealTime APOE (EUROIMMUN), which enables simultaneous testing for all six APOE genotypes (ɛ2/ɛ2, ɛ2/ɛ3, ɛ2/ɛ4, ɛ3/ɛ3, ɛ3/ɛ4, and ɛ4/ɛ4) by real-time PCR, was performed using genomic DNA (gDNA) isolated from EDTA blood samples. The PCR amplification results were evaluated using the EURORealTime Analysis Software (EUROIMMUN). Samples from healthy blood donors (HBD) were used to assess intra-assay, inter-assay and between-lot precision (n=6) as well as analytical sensitivity (n=21), with each APOE genotype represented by at least one sample. Assay accuracy was analyzed by comparing genotype assignments to the results of the CE-IVD-marked EUROArray APOE (EUROIMMUN) and bidirectional Sanger sequencing using 110 samples (100 AD, 10 HBD). APOE genotype frequencies were compared between patients (100 AD) and controls (250 HBD). Results Precision testing of the EURORealTime APOE resulted in 100% correct genotype calls. Assessment of the analytical sensitivity revealed valid and correct genotype assignment in all 21 samples, confirming 1 ng/µl as the recommended minimum gDNA concentration. The analytical accuracy amounted to 100% based on agreement with the two reference methods in 110/110 cases. Comparison of the APOE genotype distribution showed a higher proportion of ɛ4 allele carriers (i.e., ɛ2/ɛ4, ɛ3/ɛ4, and ɛ4/ɛ4) in AD patients than in HBD (50.0% vs. 25.2%). The prevalence of the ɛ4/ɛ4 genotype in these cohorts was 25.0% for AD patients compared with 2.8% for HBD. Conclusions The well-established high prevalence of the APOE-ɛ4/ɛ4 genotype in AD patients, together with the increased risk of ARIA-E in these homozygous carriers, substantiates the relevance of APOE genotyping prior to anti-amyloid treatment. The EURORealTime APOE test provides sensitive and reliable determination of APOE alleles, thus presenting a suitable tool to improve risk stratification for potential LEQEMBI recipients.

Impact of APOE ε4 and ε2 on plasma neurofilament light chain and cognition in autosomal dominant Alzheimer’s disease

BackgroundApolipoprotein E (APOE) genotypes have been suggested to influence cognitive impairment and clinical onset in presenilin-1 (PSEN1) E280A carriers for autosomal dominant Alzheimer’s disease (ADAD). Less is known about their impact on the trajectory of biomarker changes. Neurofilament light chain (NfL), a marker of neurodegeneration, begins to accumulate in plasma about 20 years prior to the clinical onset of ADAD. In this study we investigated the impact of APOE ε4 and ε2 variants on age-related plasma NfL increases and cognition in PSEN1 E280A mutation carriers.MethodsWe analyzed cross-sectional data from PSEN1 E280A mutation carriers and non-carriers recruited from the Alzheimer’s Prevention Initiative Registry of ADAD. All participants over 18 years with available APOE genotype, plasma NfL, and neuropsychological evaluation were included in this study. APOE genotypes and plasma NfL concentrations were characterized for each participant. Cubic spline models using a Hamiltonian Markov chain Monte Carlo method were used to characterize the respective impact of at least one APOE ε4 or ε2 allele on age-related log-transformed plasma NfL increases. Linear regression models were estimated to explore the impact of APOE ε4 and ε2 variants and plasma NfL on a composite cognitive test score in the ADAD mutation carrier and non-carrier groups.ResultsAnalyses included 788 PSEN1 E280A mutation carriers (169 APOE ε4 + , 114 ε2 +) and 650 mutation non-carriers (165 APOE ε4 + , 80 ε2 +), aged 18–75 years. APOE ε4 allele carriers were distinguished from ε4 non-carriers by greater age-related NfL elevations in the ADAD mutation carrier group, beginning about three years after the mutation carriers’ estimated median age at mild cognitive impairment onset. APOE ε2 allele carriers had lower plasma NfL concentrations than ε2 non-carriers in both the ADAD mutation carrier and non-carrier groups, unrelated to age, and an attenuated relationship between higher NfL levels on cognitive decline in the ADAD mutation carrier group.ConclusionsAPOE ε4 accelerates age-related plasma NfL increases and APOE ε2 attenuates the relationship between higher plasma NfL levels and cognitive decline in ADAD. NfL may be a useful biomarker to assess clinical efficacy of APOE-modifying drugs with the potential to help in the treatment and prevention of ADAD.

BEATRICE: Bayesian fine-mapping from summary data using deep variational inference.

We introduce a novel framework BEATRICE to identify putative causal variants from GWAS statistics. Identifying causal variants is challenging due to their sparsity and high correlation in the nearby regions. To account for these challenges, we rely on a hierarchical Bayesian model that imposes a binary concrete prior on the set of causal variants. We derive a variational algorithm for this fine-mapping problem by minimizing the KL divergence between an approximate density and the posterior probability distribution of the causal configurations. Correspondingly, we use a deep neural network as an inference machine to estimate the parameters of our proposal distribution. Our stochastic optimization procedure allows us to sample from the space of causal configurations, which we use to compute the posterior inclusion probabilities and determine credible sets for each causal variant. We conduct a detailed simulation study to quantify the performance of our framework against two state-of-the-art baseline methods across different numbers of causal variants and noise paradigms, as defined by the relative genetic contributions of causal and noncausal variants. We demonstrate that BEATRICE achieves uniformly better coverage with comparable power and set sizes, and that the performance gain increases with the number of causal variants. We also show the efficacy BEATRICE in finding causal variants from the GWAS study of Alzheimer's disease. In comparison to the baselines, only BEATRICE can successfully find the APOE ϵ2 allele, a commonly associated variant of Alzheimer's. BEATRICE is available for download at https://github.com/sayangsep/Beatrice-Finemapping.

Role of Apolipoprotein E in Alzheimer's Disease Pathogenesis, Prognosis and Treatment.

Alzheimer's disease (AD) is an incurable and progressive neurodegenerative disease with increasing prevalence worldwide. Previous trials of anti-amyloid and anti-tau immunotherapy indicate that additional research needs to be conducted on other mechanisms to find curative or disease-modifying therapy. This review focuses on apolipoprotein E (ApoE), a critical protein in brain lipid metabolism that acts specifically in the clearance and transport of lipids and cholesterol. The ApoE4 allele confers substantial gene dose-dependent risk of developing AD and lowers the age of onset of AD, although the mechanisms of influence remain incompletely understood. The other isoforms bring different levels of AD risk. ApoE2 is protective while ApoE3 is the most common isoform and is considered neutral. An overview is presented of the latest information on the role of ApoE in AD pathogenesis with an emphasis on pathways that are involved in AD development and interactions with crucial processes in different cell types in the brain. Elucidating the key interactions of ApoE with multiple aspects of brain function can be useful for designing novel ApoE-targeted therapeutic approaches.

Brain network fingerprints of Alzheimer's disease risk factors in mouse models with humanized APOE alleles

Alzheimer's disease (AD) presents complex challenges due to its multifactorial nature, poorly understood etiology, and late detection. The mechanisms through which genetic and modifiable risk factors influence disease susceptibility are under intense investigation, with APOE being the major genetic risk factor for late onset AD. Yet the impact of unique risk factors on brain networks is difficult to disentangle, and their interactions remain unclear.To model multiple risk factors, including APOE genotype, age, sex, diet, and immunity we used a cross sectional design, leveraging mice expressing human APOE and NOS2 genes, conferring a reduced immune response compared to mouse Nos2. We used network topological and GraphClass analyses of brain connectomes derived from accelerated diffusion-weighted MRI to assess the global and local impact of risk factors, in the absence of AD pathology.Aging and a high-fat diet impacted extensive networks comprising AD-vulnerable regions, including the temporal association cortex, amygdala, and the periaqueductal gray, involved in stress responses. Sex impacted networks including sexually dimorphic regions (thalamus, insula, hypothalamus) and key memory-processing areas (fimbria, septum). APOE genotypes modulated connectivity in memory, sensory, and motor regions, while diet and immunity both impacted the insula and hypothalamus. Notably, these risk factors converged on a circuit comprising 63 of 54,946 total connections (0.11% of the connectome), highlighting shared vulnerability amongst multiple AD risk factors in regions essential for sensory integration, emotional regulation, decision making, motor coordination, memory, homeostasis, and interoception. APOE genotype specific immune signatures support the design of interventions tailored to risk profiles. Sparse Canonical Correlation Analysis (CCA) including spatial memory as a risk factor resulted in a network comprising 80 edges, showing significant overlap with risk-associated networks from GraphClass. The largest overlaps were observed with networks impacted by diet (47 edges), immunity (39 edges), APOE3 vs 4 (26 edges), sex (23 edges), and age (19 edges), the resulting networks supporting the use of sensory cues in spatial memory retrieval.These network-based biomarkers hold translational value for distinguishing high-risk versus low-risk participants at preclinical AD stages, suggest circuits as potential therapeutic targets, and advance our understanding of network fingerprints associated with AD risk.

Synergistic Effect between the APOE ε4 Allele with Genetic Variants of GSK3B and MAPT: Differential Profile between Refractory Epilepsy and Alzheimer Disease.

Temporal Lobe Epilepsy (TLE) is a chronic neurological disorder characterized by recurrent focal seizures originating in the temporal lobe. Despite the variety of antiseizure drugs currently available to treat TLE, about 30% of cases continue to have seizures. The etiology of TLE is complex and multifactorial. Increasing evidence indicates that Alzheimer's disease (AD) and drug-resistant TLE present common pathological features that may induce hyperexcitability, especially aberrant hyperphosphorylation of tau protein. Genetic polymorphic variants located in genes of the microtubule-associated protein tau (MAPT) and glycogen synthase kinase-3β (GSK3B) have been associated with the risk of developing AD. The APOE ε4 allele is a major genetic risk factor for AD. Likewise, a gene-dose-dependent effect of ε4 seems to influence TLE. The present study aimed to investigate whether the APOE ɛ4 allele and genetic variants located in the MAPT and GSK3B genes are associated with the risk of developing AD and drug-resistant TLE in a cohort of the Mexican population. A significant association with the APOE ε4 allele was observed in patients with AD and TLE. Additional genetic interactions were identified between this allele and variants of the MAPT and GSK3B genes.

Elevated blood glucose levels are associated with the progression of brain hypometabolism, and HDL-C and APOE4 add to this association.

Brain glucose hypometabolism has consistently been found in neurodegenerative disorders, including Alzheimer's disease (AD). High blood glucose and HDL cholesterol (HDL-C) levels have also been linked to neurodegeneration and AD. However, there is limited understanding of the relationships between dementia-related risk factors in the brain and blood. A linear mixed model was used to examine the relationship between blood glucose and HDL-C levels and the progression of brain hypometabolism, adjusting for APOE4 and other clinical covariates. The hypometabolic convergence index (HCI) was measured by fluorodeoxyglucose-18 (FDG) positron emission tomography (PET) in participants from the Alzheimer's Disease Neuroimaging Initiative (ADNI). Data visualizations were generated to understand the joint effects of plasma glucose, HDL-C, and APOE4 on HCI. There were 336 individuals (781 observations), of whom 22.62% had AD. The majority were male (63.98%) and of white race, and 48.51% were carriers of APOE4. Over time, high blood glucose level was associated with the progression of brain glucose hypometabolism (β=0.33, 95% CI: 0.02, 0.64, p<0.05). A high plasma HDL-C level (β=1.22, 95% CI: 0.09, 2.35, p<0.05), more study visits (β=1.67, 95% CI: 1.37, 1.98, p<0.001), and being an APOE4 allele carrier (β=1.29, 95% CI: 0.15, 2.42, p<0.05) were also significant predictors of brain hypometabolism progression. APOE4 carrier status and number of visits account for the largest proportion of the variance from the fixed effects model. Random effects due to participant characteristics and fixed effects together accounted for 95.2% of the model variance. Subgroup analysis revealed that these effects were observed only in those without AD. High plasma glucose levels facilitated the progression of brain hypometabolism. The effect was more prominent in the APOE4 double-carriers with elevated HDL-C. Elevated blood glucose may reflect systemic insulin resistance, which could impair brain glucose uptake, resulting in brain hypometabolism. Controlling blood glucose and HDL-C levels in APOE4 carriers may improve brain metabolism, potentially delaying the onset of dementia.

Correlation of APOE polymorphism, expression, and plasma levels with cardiac comorbidities among lipodystrophy in HIV-infected patients

Lipodystrophy in HIV-infected patients (LDHIV) includes morphological and metabolic abnormalities, including lipid and glucose metabolism. ApoE plays a role in the transport and clearance of lipoprotein. In the general population, ApoE 112 (rs429358) and 158 (rs7412) polymorphisms were linked to severe dyslipidemia. Therefore, we investigated ApoE polymorphism using PCR-RFLP in 200 HIV patients (100 with HIV-associated lipodystrophy (HIVLD), 100 without HIVLD), as well as 100 healthy controls. We also assessed ApoE expression using qRT-PCR and measured its level using ELISA. The APOE 4/4, 3/4, and 2/4 genotypes have been associated with a decreased risk of HIV-1 infection. (P = 0.0001, OR = 0.18; P = 0.006, OR = 0.87; P = 0.006, OR = 0.09) when compared between HIV-positive individuals and healthy controls. Conversely, APOE allele 2 was linked to a higher risk of acquiring HIV-1 (P = 0.03, OR = 3.02). APOE allele 2 was linked to a higher likelihood of HIVLD severity when compared between patients with and without HIVLD (P = 0.05, OR = 2.82). When comparing patients with HIVLD to healthy controls, the APOE 4/4 and 2/4 genotypes as well as allele 4 were linked with the reduced risk of LDHIV (P = 0.0006, OR = 0.21; P = 0.01, OR = 0.18; P = 0.0002, OR = 0.40). When compared to patients without HIVLD from healthy controls, the ApoE 4/4 genotype, 2 and 4 alleles, were linked to a reduced risk of developing HIVLD (P = 0.0009, OR = 0.14; P = 0.0001, OR = 0.17; P = 0.00001, OR = 0.39). When comparing impaired to normal cholesterol levels in patients without HIVLD, the ApoE 3/4 genotype was linked with the increased risk of impaired cholesterol levels (P = 0.02, OR = 3.37). When comparing impaired and normal glucose levels in patients without HIVLD, the ApoE 4/4 genotype was associated to an elevated risk of impaired glucose levels (P = 0.03, OR = 8.27). In multivariate analysis, independent impaired cholesterol, LDL, and glucose levels were associated with a higher risk of lipodystrophy severity (P = 0.04, OR = 2.33; P = 0.001, OR = 4.05; P = 0.05, OR = 2.63). ApoE expression was up-regulated in LDHIV with a fold change value of 4.02 compared to those without HIVLD. ApoE protein level was found to be higher in patients of the HIVLD group (3.01 mg/dL) compared to those without HIVLD group (2.83 mg/dL). In conclusion, individuals with ApoE allele 2 were at higher risk for HIV-1 acquisition and severity of HIVLD, whereas those with ApoE allele 4 were at reduced HIVLD severity and development risk. It’s possible that ApoE’s increased level and its overexpression are related to the ApoE allele 2 in HIVLD patients. The development of LDHIV may be facilitated by the APOE 3/4 and 4/4 genotypes as well as abnormal glucose and cholesterol levels.

Autoencoder imputation of missing heterogeneous data for Alzheimer's disease classification

AbstractMissing Alzheimer's disease (AD) data is prevalent and poses significant challenges for AD diagnosis. Previous studies have explored various data imputation approaches on AD data, but the systematic evaluation of deep learning algorithms for imputing heterogeneous and comprehensive AD data is limited. This study investigates the efficacy of denoising autoencoder‐based imputation of missing key features of heterogeneous data that comprised tau‐PET, MRI, cognitive and functional assessments, genotype, sociodemographic, and medical history. The authors focused on extreme (≥40%) missing at random of key features which depend on AD progression; identified as the history of a mother having AD, APoE ε4 alleles, and clinical dementia rating. Along with features selected using traditional feature selection methods, latent features extracted from the denoising autoencoder are incorporated for subsequent classification. Using random forest classification with 10‐fold cross‐validation, robust AD predictive performance of imputed datasets (accuracy: 79%–85%; precision: 71%–85%) across missingness levels, and high recall values with 40% missingness are found. Further, the feature‐selected dataset using feature selection methods, including autoencoder, demonstrated higher classification score than that of the original complete dataset. These results highlight the effectiveness and robustness of autoencoder in imputing crucial information for reliable AD prediction in AI‐based clinical decision support systems.

Association of apolipoprotein E gene polymorphism with gallstone disease in Iraqi Kurdish women

Gallstone disease (GSD) is a worldwide problem; the frequency of GSD varies greatly amongst different ethnic groups, possibly due to environmental and genetic factors. One circulating lipoprotein involved in lipid metabolism is apolipoprotein E (APOE). The APOE gene is polymorphic, has three distinct alleles, APOE2, APOE3, and APOE4. The an APOE polymorphism is linked to a variety of diseases, including Alzheimer's and type-two diabetes, so this study aimed to assess the relationship among various APOE genotypes and alleles with gallstone cases in Iraqi Kurdish women. The present case-control study involved 81 cases with laparoscopic cholecystectomy for gallstone disease and 80 healthy women without GSD. Genomic DNA samples were taken from blood to find the genotype of APOE using allele-specific sequence-primers and a method based on polymerase chain reaction (PCR). lipid profiles were examined using an automated biochemical analyzer. SPSS and GraphPad Prism 9.1.1 software were used to conduct the statistical analysis. No significant relationships were found between healthy people and GSD patients in genotype and allele frequencies. However, the genotype for E3/E4 and the APOE4 allele in GSD patients were higher than the controls (9.88% vs. 5.0% and 4.94% vs. 2.5%, respectively; P &lt;0.05) but statistically nonsignificant. serum levels of cholesterol, low-density lipoproteins, and very low-density lipoproteins were higher, and the levels of serum high-density lipoprotein was lower than controls. These findings revealed no connection between the examined polymorphisms and gallstone cases. Additionally, it was demonstrated that gallstone disease and lipid parameters had a favorable relationship. Keywords: Apolipoprotein E, APOE, Gallstone disease, Genotype, Polymorphisms.

B - 55 Diffusion Tensor Imaging Analysis of Former American Football Players Exposed to Repetitive Head Impacts

Abstract Objective Exposure to repetitive head impacts (RHI) has been linked to Chronic Traumatic Encephalopathy (CTE) and neuropathological alterations such as white matter shear injuries. In this study, we use diffusion-tensor imaging (DTI) to investigate in vivo white matter alterations among former American football players. We also investigate how age and factors associated with RHI exposure influence white matter integrity. Methods We analyzed data from the DIAGNOSE CTE Research Project, focusing on former American football players (n = 166). The measures included whole-brain Fractional Anisotropy (FA), reflecting water diffusion directionality in white matter, and FreeWater-corrected FA (FAt) accounting for extracellular free water, using FSL Tract-Based Spatial Statistics (TBSS). We performed linear regressions on FA and FAt with age, age of first exposure to football, and estimates of cumulative head impact index (CHII) scores of frequency, linear acceleration, and rotational force controlling for age, body mass index, race, education, and APOE e4 allele presence as covariates. Results Both FA (p &amp;lt; 0.00001) and FAt (p &amp;lt; 0.00001) decreased as age increased. Moreover, FA (p &amp;lt; 0.01) and FAt (p &amp;lt; 0.01) were significantly lower with an earlier age of first exposure to football. Finally, FAt decreased as CHII linear acceleration (p &amp;lt; 0.04) and rotational forces (p &amp;lt; 0.02) increased. Conclusion Our study reveals age-related declines in both FA and FAt and highlights that the duration and intensity of exposure to RHI have an impact on white matter microstructure later in life. Overall, these results underscore the impact of prolonged exposure to RHI on white matter microstructure.

Apolipoprotein E and Alzheimer's Disease in Italian Population: Systematic Review and Meta-Analysis.

Objective: This meta-analysis with a systematic review was undertaken to assess the association between APOE allelic genotypes and the risk of Alzheimer's disease (AD) in the Italian population. Methods: The Web of Science, PubMed, and Scopus databases were searched until 15 November 2023. The odds ratio (OR) with a 95% confidence interval (CI) was calculated using fixed and random effect models, depending on the I2 statistic value. The systematic review and meta-analysis were conducted in agreement with the PRISMA guideline and registered with PROSPERO (CRD42023492580). Results: Our meta-analysis based on 15 studies revealed a higher risk of AD among Italian individuals carrying the APOE ε4 allele (OR = 3.60, 95% CI [2.90-4.47], p < 0.0001). The association of AD genotype APOE ε2ε4 (OR = 1.36, 95% CI [0.76-2.41], p = 0.29) was not statistically significant, while APOE ε3ε4 (OR = 3.43, 95% CI [2.95-3.99], p < 0.0001) has a high risk of AD development; the risk is more notably in the APOE ε4ε4 genotype (OR = 7.08, 95% CI [4.22-11.86], p < 0.0001). The APOE ε2 allele has a protective effect (APOE ε2 (OR = 0.47, 95% CI [0.29-0.74], p = 0.0013)), and similar results were achieved by APOE ε3 (OR = 0.49, 95% CI [0.37-0.65], p < 0.0001). Subgroup analysis of three areas of Italy (southern, northern, and center) revealed that that APOE ε4 allele was a risk factor with a higher OR in northern Italy (OR 4.22; 95% CI [3.46-5.16], p < 0.0001) compared to southern and center Italy (OR 3.02; 95% CI [2.28-4.01], p < 0.0001 and OR 3.97; 95% CI [1.37-11.56], p < 0.0001, respectively). As well, APOE ε4ε4 genotype carriers had a significantly higher OR in northern Italy (OR 9.69; 95% CI [4.94-18.99], p < 0.0001) compared to in southern and center Italy (OR 4.38; 95% CI [1.54-12.47], p < 0.0001 and OR 3.59; 95% CI [0.87-14.86], p < 0.0001, respectively). Conclusions: This systematic review with a meta-analysis of the Italian population on APOE alleles, genotyping, and AD incidence, highlights that individuals harboring APOE ε4 have a higher risk of developing AD compared to those with other alleles. It also supports the protective effect of the APOE ε2 allele against the progress of AD. The qualitative analysis on the complex genetic interactions influencing Alzheimer risk emphasizes the need for further research on genetic and environmental factors for effective prevention strategies.