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BACKGROUND: Exposure to air pollution is associated with worldwide morbidity and mortality. Diesel exhaust (DE) emissions are important contributors which induce vascular inflammation and metabolic disturbances by unknown mechanisms. We aimed to determine molecular pathways activated by DE in the liver that could be responsible for its cardiometabolic toxicity. METHODS: Apolipoprotein E knockout (ApoE KO) mice were exposed to DE or filtered air (FA) for two weeks, or DE for two weeks followed by FA for 1 week. Expression microarrays and global metabolomics assessment were performed in the liver. An integrated transcriptomic and metabolomic analytical strategy was employed to dissect critical pathways and identify candidate genes that could dissect DE-induced pathogenesis. HepG2 cells were treated with an organic extract of DE particles (DEP) vs. vehicle control to test candidate genes. RESULTS: DE exposure for 2 weeks dysregulated 658 liver genes overrepresented in whole cell metabolic pathways, especially including lipid and carbohydrate metabolism, and the respiratory electron transport pathway. DE exposure significantly dysregulated 118 metabolites, resulting in increased levels of triglycerides and fatty acids due to mitochondrial dysfunction as well as increased levels of glucose and oligosaccharides. Consistently, DEP treatment of HepG2 cells led to increased gluconeogenesis and glycogenolysis indicating the ability of the in-vitro approach to model effects induced by DE in vivo. As an example, while gene network analysis of DE livers identified phosphoenolpyruvate carboxykinase 1 (Pck1) as a key driver gene of DE response, DEP treatment of HepG2 cells resulted in increased mRNA expression of Pck1 and glucose production, the latter replicated in mouse primary hepatocytes. Importantly, Pck1 inhibitor mercaptopicolinic acid suppressed DE-induced glucose production in HepG2 cells indicating that DE-induced elevation of hepatic glucose was due in part to upregulation of Pck1 and increased gluconeogenesis. CONCLUSIONS: Short-term exposure to DE induced widespread alterations in metabolic pathways in the liver of ApoE KO mice, especially involving carbohydrate and lipid metabolism, together with mitochondrial dysfunction. Pck1 was identified as a key driver gene regulating increased glucose production by activation of the gluconeogenesis pathway.

IntroductionEvaluating the generalizability of dementia risk scores, primarily developed in non-Latinx White (NLW) participants, and interactions with genetic risk factors in diverse populations is crucial for addressing health disparities.MethodsWe analyzed the association of the Cardiovascular Risk Factors, Aging, and Incidence of Dementia (CAIDE) and modified CAIDE (mCAIDE) scores with dementia risk using logistic regression models stratified by race/ethnicity in National Alzheimer's Coordinating Center (NACC) and Alzheimer's Disease Neuroimaging Initiative (ADNI), and assessed their interaction with apolipoprotein E (APOE).ResultsHigher CAIDE scores were associated with an increased risk of dementia in Asian, Latinx, and NLW participants but not in Black participants. In contrast, higher mCAIDE scores were also associated with an increased risk of dementia in Black participants. Unfavorable mCAIDE risk profiles exacerbated the apolipoprotein E*ε4 (APOE*ε4) risk effect and attenuated the APOE*ε2 protective effect.DiscussionOur findings underscore the importance of evaluating the validity of dementia risk scores in diverse populations for their use in personalized medicine approaches to promote brain health.HighlightsDementia risk scores demonstrate race/ethnic-specific effects on dementia risk. Unfavorable modifiable risk profiles moderate the effect of APOE on dementia risk. Dementia risk scores need to be validated in diverse populations.

ObjectiveThe gene encoding TOMM40 (Transporter of Outer Mitochondrial Membrane 40) is adjacent to that encoding APOE, which has a central role in lipid and lipoprotein metabolism. While human genetic variants near APOE and TOMM40 have been shown to be strongly associated with plasma lipid levels, a specific role for TOMM40 in lipid metabolism has not been established, and the present study was aimed at assessing this possibility.MethodsTOMM40 was knocked down by siRNA in human hepatoma HepG2 cells, and effects on mitochondrial function, lipid phenotypes, and crosstalk between mitochondria, ER, and lipid droplets were examined. Additionally, hepatic and plasma lipid levels were measured in mice following shRNA-induced knockdown of Tomm40 shRNA.ResultsIn HepG2 cells, TOMM40 knockdown upregulated expression of APOE and LDLR in part via activation of LXRB (NR1H2) by oxysterols, with consequent increased uptake of VLDL and LDL. This is in part due to disruption of mitochondria-endoplasmic reticulum contact sites, with resulting accrual of reactive oxygen species and non-enzymatically derived oxysterols. With TOMM40 knockdown, cellular triglyceride and lipid droplet content were increased, effects attributable in part to receptor-mediated VLDL uptake, since lipid staining was significantly reduced by concomitant suppression of either LDLR or APOE. In contrast, cellular cholesterol content was reduced due to LXRB-mediated upregulation of the ABCA1 transporter as well as increased production and secretion of oxysterol-derived cholic acid. Consistent with the findings in hepatoma cells, in vivo knockdown of TOMM40 in mice resulted in significant reductions of plasma triglyceride and cholesterol concentrations, reduced hepatic cholesterol and increased triglyceride content, and accumulation of lipid droplets leading to development of steatosis.ConclusionsThese findings demonstrate a role for TOMM40 in regulating hepatic lipid and plasma lipoprotein levels and identify mechanisms linking mitochondrial function with lipid metabolism.

IntroductionBlood-brain barrier (BBB) dysfunction occurs in Alzheimer's disease (AD). Yet, the stage at which it appears along the AD time course and whether it contributes to neurodegeneration remain unclear.MethodsOlder adults (61 to 90 years) from cognitively normal (CN) to mildly cognitively impaired (CI), enriched for APOE ?4 and amyloid positivity, underwent dynamic contrast-enhanced (DCE) magnetic resonance imaging (MRI) and diffusion MRI to measure BBB permeability and brain microstructure. Analysis of variance compared BBB permeability according to cognitive status, amyloid beta (Aβ), and APOE4. Linear regressions assessed associations of BBB permeability with brain microstructure and interactions with Aβ and APOE4.ResultsBBB permeability was elevated for APOE4 carriers across the cortical gray matter, with the strongest differences among CN amyloid-negative individuals. Associations between entorhinal BBB permeability and microstructure interacted with Aβ and APOE4, with the strongest relationships in amyloid-positive individuals and APOE4 carriers.DiscussionAPOE4 may drive widespread BBB dysfunction in preclinical AD, which may contribute to neurodegenerative changes early along the AD cascade.HighlightsGray matter blood-brain barrier (BBB) permeability is elevated for APOE4 carriers. APOE4-related BBB breakdown appears in the absence of cognitive decline or amyloid. BBB leakage correlates with entorhinal cortex microstructural injury. Associations with microstructure are strongest for amyloid-positive APOE4 carriers.

BACKGROUND: Apolipoprotein E (APOE) genotypes have been suggested to influence cognitive impairment and clinical onset in presenilin-1 (PSEN1) E280A carriers for autosomal dominant Alzheimers 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. METHODS: We analyzed cross-sectional data from PSEN1 E280A mutation carriers and non-carriers recruited from the Alzheimers 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. RESULTS: Analyses 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. CONCLUSIONS: APOE 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.

INTRODUCTION: The apolipoprotein E gene (APOE) is an established central player in the pathogenesis of Alzheimers disease (AD), with distinct apoE isoforms exerting diverse effects. apoE influences not only amyloid-beta and tau pathologies but also lipid and energy metabolism, neuroinflammation, cerebral vascular health, and sex-dependent disease manifestations. Furthermore, ancestral background may significantly impact the link between APOE and AD, underscoring the need for more inclusive research. METHODS: In 2023, the Alzheimers Association convened multidisciplinary researchers at the AAIC Advancements: APOE conference to discuss various topics, including apoE isoforms and their roles in AD pathogenesis, progress in apoE-targeted therapeutic strategies, updates on disease models and interventions that modulate apoE expression and function. RESULTS: This manuscript presents highlights from the conference and provides an overview of opportunities for further research in the field. DISCUSSION: Understanding apoEs multifaceted roles in AD pathogenesis will help develop targeted interventions for AD and advance the field of AD precision medicine. HIGHLIGHTS: APOE is a central player in the pathogenesis of Alzheimers disease. APOE exerts a numerous effects throughout the brain on amyloid-beta, tau, and other pathways. The AAIC Advancements: APOE conference encouraged discussions and collaborations on understanding the role of APOE.

Alzheimers disease typically progresses in stages, which have been defined by the presence of disease-specific biomarkers: amyloid (A), tau (T) and neurodegeneration (N). This progression of biomarkers has been condensed into the ATN framework, in which each of the biomarkers can be either positive (+) or negative (-). Over the past decades, genome-wide association studies have implicated ∼90 different loci involved with the development of late-onset Alzheimers disease. Here, we investigate whether genetic risk for Alzheimers disease contributes equally to the progression in different disease stages or whether it exhibits a stage-dependent effect. Amyloid (A) and tau (T) status was defined using a combination of available PET and CSF biomarkers in the Alzheimers Disease Neuroimaging Initiative cohort. In 312 participants with biomarker-confirmed A-T- status, we used Cox proportional hazards models to estimate the contribution of APOE and polygenic risk scores (beyond APOE) to convert to A+T- status (65 conversions). Furthermore, we repeated the analysis in 290 participants with A+T- status and investigated the genetic contribution to conversion to A+T+ (45 conversions). Both survival analyses were adjusted for age, sex and years of education. For progression from A-T- to A+T-, APOE-e4 burden showed a significant effect [hazard ratio (HR) = 2.88; 95% confidence interval (CI): 1.70-4.89; P < 0.001], whereas polygenic risk did not (HR = 1.09; 95% CI: 0.84-1.42; P = 0.53). Conversely, for the transition from A+T- to A+T+, the contribution of APOE-e4 burden was reduced (HR = 1.62; 95% CI: 1.05-2.51; P = 0.031), whereas the polygenic risk showed an increased contribution (HR = 1.73; 95% CI: 1.27-2.36; P < 0.001). The marginal APOE effect was driven by e4 homozygotes (HR = 2.58; 95% CI: 1.05-6.35; P = 0.039) as opposed to e4 heterozygotes (HR = 1.74; 95% CI: 0.87-3.49; P = 0.12). The genetic risk for late-onset Alzheimers disease unfolds in a disease stage-dependent fashion. A better understanding of the interplay between disease stage and genetic risk can lead to a more mechanistic understanding of the transition between ATN stages and a better understanding of the molecular processes leading to Alzheimers disease, in addition to opening therapeutic windows for targeted interventions.

Up to 80% of Parkinson's disease patients develop dementia, but time to dementia varies widely from motor symptom onset. Dementia with Lewy bodies presents with clinical features similar to Parkinson's disease dementia, but cognitive impairment precedes or coincides with motor onset. It remains controversial whether dementia with Lewy bodies and Parkinson's disease dementia are distinct conditions or represent part of a disease spectrum. The biological mechanisms underlying disease heterogeneity, in particular the development of dementia, remain poorly understood, but will likely be the key to understanding disease pathways and, ultimately, therapy development. Previous genome-wide association studies in Parkinson's disease and dementia with Lewy bodies/Parkinson's disease dementia have identified risk loci differentiating patients from controls. We collated data for 7804 patients of European ancestry from Tracking Parkinson's, The Oxford Discovery Cohort, and Accelerating Medicine Partnership-Parkinson's Disease Initiative. We conducted a discrete phenotype genome-wide association study comparing Lewy body diseases with and without dementia to decode disease heterogeneity by investigating the genetic drivers of dementia in Lewy body diseases. We found that risk allele rs429358 tagging APOEe4 increases the odds of developing dementia, and that rs7668531 near the MMRN1 and SNCA-AS1 genes and an intronic variant rs17442721 tagging LRRK2 G2019S on chromosome 12 are protective against dementia. These results should be validated in autopsy-confirmed cases in future studies.

Patients with chronic inflammatory disorders such as psoriasis have an increased risk of cardiovascular disease and elevated levels of LL37, a cathelicidin host defense peptide that has both antimicrobial and proinflammatory properties. To explore whether LL37 could contribute to the risk of heart disease, we examined its effects on lipoprotein metabolism and show that LL37 enhanced LDL uptake in macrophages through the LDL receptor (LDLR), scavenger receptor class B member 1 (SR-B1), and CD36. This interaction led to increased cytosolic cholesterol in macrophages and changes in expression of lipid metabolism genes consistent with increased cholesterol uptake. Structure-function analysis and synchrotron small-angle x-ray scattering showed structural determinants of the LL37-LDL complex that underlie its ability to bind its receptors and promote uptake. This function of LDL uptake is unique to cathelicidins from humans and some primates and was not observed with cathelicidins from mice or rabbits. Notably, Apoe-/- mice expressing LL37 developed larger atheroma plaques than did control mice, and a positive correlation between plasma LL37 and oxidized phospholipid on apolipoprotein B (OxPL-apoB) levels was observed in individuals with cardiovascular disease. These findings provide evidence that LDL uptake can be increased via interaction with LL37 and may explain the increased risk of cardiovascular disease associated with chronic inflammatory disorders.

Introduction: Temporal lobe epilepsy is the most common form of focal epilepsy, often associated with cognitive impairments, particularly in memory functions, and depression. Sex and APOE ε4 genotype play a crucial role in modulating cognitive outcomes and depression in various neurological conditions like Alzheimer's disease. However, the combined effects of APOE genotype and sex on cognitive performance and depression in temporal lobe epilepsy have not been previously investigated. Objective: This study aims to (i) identify impaired cognitive performance and clinically relevant depression; (ii) explore the interaction between sex and APOE ε4 genotype on cognitive performance and depression in individuals with temporal lobe epilepsy. Methods: We used a comprehensive battery of neuropsychological tests to assess domains such as learning and memory, attention, executive functions, language, and visuo-spatial constructional skills and the Hamilton Depression Rating Scale. We also performed APOE genotyping to assess its role in the study. The final sample was composed by fifty-four patients (53.7% female). Cognitive performance and depression were analyzed using normative cut-off scores. To examine the main effects and interactions of sex and APOE ε4 carrier status on neuropsychological test scores and the Hamilton Depression Rating Scale, we also conducted a two-way Analysis of Variance (ANOVA). Results: Female APOE ε4 carriers compared to normative cut-offs, exhibited poor performance on multiple test scores, including the MMSE, The Rey Auditory Verbal Learning Test (immediate and delayed recall), The Corsi Block-Tapping Task, The Verbal Fluency Test, The Raven's Standard Progressive Matrices and The Pentagon-copying Test. Males showed impairment only in visuo-spatial short-term memory. ANOVA analysis revealed significant main effects of APOE ε4 status and sex on the MMSE, The Rey Auditory Verbal Learning Test, The Verbal Fluency, The Raven's Standard Progressive Matrices and The Pentagon-copying Test scores. Specifically, female APOE ε4 carriers performed consistently worse than other groups on many tasks. For depression, only an effect of sex emerged. Females scored higher besides APOE genotype. Conclusions: These findings underscore the importance of considering both sex and APOE genotype when assessing cognitive performance in patients with temporal lobe epilepsy. The significant cognitive deficits we observed among females carrying the APOE ε4 allele highlight previously unexplored genetic and sex-related influences on cognition. This has potential implications for personalized therapeutic strategies, emphasizing the need for targeted assessment and intervention. [ABSTRACT FROM AUTHOR]

TREM2 is a signaling receptor expressed on microglia that has emerged as an important drug target for Alzheimer's disease and other neurodegenerative diseases. While a number of TREM2 ligands have been identified, little is known regarding the structural details of how they engage. To better understand this, we created a protein library of 28 different TREM2 variants that could be used to map interactions with various ligands using biolayer interferometry. The variants are located in previously identified putative binding surfaces on TREM2 called the hydrophobic site, basic site, and site 2. We found that mutations to the hydrophobic site ablated binding to apoE4 and TDP-43. Competition binding experiments indicated that apoE4 and oAβ42 share overlapping binding sites on TREM2. In contrast, binding to C1q was disrupted most strongly by mutations to the basic site, including R46, with some mutations to the hydrophobic site also attenuating binding, thus suggesting a broader mediation of binding across the two sites. Supporting this, competition experiments indicated that C1q binding could be blocked by both apoE and oAβ42. TREM2 binding to IL-34 was mediated by the basic site at a surface centering on R76. Competition binding experiments validated the unique site for IL-34, showing little to no competition with either oAβ42 or apoE4. However, competition experiments between C1q and IL34 suggest that the ligands compete for binding at the basic site. Altogether, our results suggest that TREM2 utilizes the hydrophobic site (consisting of CDR1, CDR2, and CDR3) as a common site to engage multiple ligands, and uses distinct basic sites to engage others. Our findings imply that pharmaceutical strategies targeting these surfaces might be effective to modulate TREM2 functions. [ABSTRACT FROM AUTHOR]

Background: APOE gene polym orphisms have been linked to Alzheimer's disease and coronary heart diseases. However, their relationship with lung adenocarcinoma (LUAD) remains uncertain. Methods: This study analyzed a cohort of 600 individuals comprising 200 LUAD patients in the lung cancer group and 400 healthy individuals as controls. APOE gene variants were identified through Sanger sequencing. Statistical analyses were conducted to assess intergroup differences, and comparisons of lipid profiles were performed across individuals carrying different APOE alleles. Results: The APOE ϵ2 allele had been significantly more frequently occurring in the LUAD group than in the control group (15.5% vs. 7%, P <0.001). APOE ϵ2/ϵ2 and ϵ2/ϵ3 genotypes increased susceptibility to LUAD by 3.78-fold and 3.22-fold. The APOE ϵ2/ϵ3 genotype increased the risk of early-stage LUAD by 2.36-fold and advanced-stage LUAD by 4.05-fold. Individuals with the APOE ϵ2/ϵ2 genotype had a 3.22-fold higher susceptibility to moderately differentiated and a 6.8-fold higher susceptibility to poorly differentiated LUAD. Patients with the ϵ2 allele in LUAD exhibited disrupted lipid metabolism, characterized by reduced HDL, TC, and FFA levels, along with increased ApoB, particularly in advanced and poorly differentiated cancer stages. Conclusion: Individuals carrying the ϵ2 allele have an increased susceptibility to developing LUAD, accompanied by disrupted lipid metabolism. Additionally, the APOE ϵ2/ϵ2 and ϵ2/ϵ3 genotypes are associated with an increased risk of developing advanced and poorly differentiated LUAD. [ABSTRACT FROM AUTHOR]

Background: Apathy in patients with Alzheimer's disease (AD) is associated with significant morbidity and is often one of the first neuropsychiatric symptoms to present in mild cognitive impairment (MCI). Apathy is associated with accelerated cognitive decline and atrophy in fronto-striatal regions of the brain. Previous work has shown a link between apathy and the APOE gene in the context of AD, as the APOE ε 4 allele is already known to be associated with the onset of AD. However, other genetic associations with apathy are largely unexplored. Objective: To examine whether interactions between genetic variants related to neurotransmitter systems and regional brain atrophy are associated with apathy in patients with MCI and AD. Methods: In a sample of individuals with AD (n = 266), MCI (n = 518), and cognitively normal controls (n = 378), a partial least squares correspondence analysis modeled interactions between single nucleotide polymorphisms, structural whole-brain imaging variables, and apathy. Results: An interaction was found between apathy, the possession of an APOE ε4 allele combined with minor homozygosity for the DAT1 (dopamine transporter 1) gene, and regional brain atrophy. This interaction was closely linked to the MCI and AD groups. Conclusions: The results point to an association of a dopaminergic genetic marker and apathy in the AD continuum and may inform future design of clinical trials of apathy, as well as new treatment targets. [ABSTRACT FROM AUTHOR]

Background: Genetic risk factors start to affect the brain and behavior in Alzheimer's disease (AD) before clinical symptoms occur. Although AD is mainly associated with memory deficits, attention and executive dysfunctions can present at the early presymptomatic stages in middle age for those with non-modifiable risks. Objective: Here, we investigated whether known risk genes for AD already affected attention in young adulthood. Methods: A total of 392 healthy young adults aged around 20 years underwent genetic testing for risks of dementia (APOE and MAPT) and performed a computerized cognitive test for temporal attention called the Attentional Blink (AB) task, in which patients with dementia tested in previous studies often showed reduced performance. Here, the AB task was analyzed using repeated-measurements analysis of variance for the ability of visual perception, attention deployment and temporal memory encoding/binding performance. Results: The results showed that all participants exhibited AB effects. Importantly, genetic risk factors had statistically significant influence on temporal attention depending on sex in healthy young adults. APOE4 status was associated with enhanced attention deployment in males but not females, while MAPT AA carriers had poorer performance in AB but only in females. No genetic effects were found for visual perception and temporal memory binding errors between high and low risk groups. Conclusions: We provided evidence that both APOE and MAPT start to affect attentional function as early as young adulthood. Furthermore, unlike previous findings in older people, these genes had a differential effect for males and females in young adults. [ABSTRACT FROM AUTHOR]

Background: Blood-based Alzheimer's disease (AD) biomarkers have been increasingly employed for diagnostic, prognostic, and therapeutic monitoring purposes, due to accuracy in distinguishing AD pathophysiologic process. Compared to other p-tau isoforms, plasma p-tau217 exhibits stronger associations with AD hallmarks in CSF and brain. However, most studies have been conducted in non-Hispanic Whites, limiting our understanding of the performances and utility of these biomarkers across ethnicities. Methods: We examined a cohort of Peruvians from the GAPP study, a recently established cohort of Peruvian mestizos from Lima and indigenous groups from Southern Peru (Aymaras and Quechuas). We tested plasma levels of p-tau using the Quanterix Simoa ALZpathp-tau217 assay in 525 samples and tested the association between p-tau217 and clinical diagnosis (healthy controls n = 234 vs. AD n = 113) using generalized mixed regression models, adjusting for sex, age, education, APOE-e4 allele (fixed effects) and study site (random effect). We also tested biomarker levels in MCI (n = 178) vs. other groups. The receiver operating characteristics area under the curve (ROC-AUC) was used to evaluate the biomarker's classification performances. Result: Participants showed on average 80% Native American ancestry. p-tau217 was significantly associated with AD (β = 2.61, 95%CI = 0.61–4.29) and its levels were inversely correlated with cognitive performances; p-tau217 levels did not differ between controls and MCI (p-value > 0.05). p-tau217 levels were higher in participants carrying at least one APOE-e4 allele (OR = 2.31, 95%CI = 1.85–2.90). The ROC-AUC for p-tau217 was estimated at 82.82% in the fully adjusted model. Conclusion: To our knowledge, this is the largest study conducted in a South American cohort phenotyped for AD with available p-tau217. Most investigations have previously focused on highly selected cohorts with established AD-endophenotypes (CSF biomarkers, autopsy report, PET etc.), while data on cohorts with clinical assessment are currently lacking, especially in non-European populations. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) is a multifactorial neurodegenerative disease mainly caused by β-amyloid (Aβ) accumulation in the brain. Among the several factors that may concur to AD development, elevated cholesterol levels and brain cholesterol dyshomeostasis have been recognized to play a relevant role. Proprotein convertase subtilisin/kexin type 9 (PCSK9) is a protein primarily known to regulate plasma low-density lipoproteins (LDLs) rich in cholesterol and to be one of the main causes of familial hypercholesterolemia. In addition to that, PCSK9 is also recognized to carry out diverse important activities in the brain, including control of neuronal differentiation, apoptosis, and, importantly, LDL receptors functionality. Moreover, PCSK9 appeared to be directly involved in some of the principal processes responsible for AD development, such as inflammation, oxidative stress, and Aβ deposition. On these bases, PCSK9 management might represent a promising approach for AD treatment. The purpose of this review is to elucidate the role of PCSK9, whether or not cholesterol-related, in AD pathogenesis and to give an updated overview of the most innovative therapeutic strategies developed so far to counteract the pleiotropic activities of both humoral and brain PCSK9, focusing in particular on their potentiality for AD management. [ABSTRACT FROM AUTHOR]

Insufficient mechanical loading impairs fracture healing; however, the underlying mechanisms remain unclear. Increasing evidence indicates that Piezo1 plays an important role in fracture healing, although the effect of Piezo1 on the endochondral ossification of chondrocytes has been overlooked. This study reports that mechanical unloading down‐regulates the expression of Piezo1 in chondrocytes and leads to fracture nonunion. Single‐cell sequencing of calluses revealed that specific deletion of Piezo1 in chondrocytes upregulated the expression of apolipoprotein E (ApoE) in hypertrophic chondrocytes, resulting in delayed cartilage‐to‐bone transition due to enhanced chondrocyte senescence. Based on these results, an injectable and thermosensitive hydrogel is developed, which released an ApoE antagonist in situ at the fracture site. This hydrogel effectively attenuated chondrocyte senescence and, thus, promoted cartilage‐to‐bone transition as well as the fracture healing process. Overall, this data provide a new perspective on the activity of chondrocytes in fracture healing and a new direction for the treatment of fracture nonunion caused by insufficient mechanical loading. [ABSTRACT FROM AUTHOR]

The major genetic risk factor for Alzheimer's disease (AD), APOE4, accelerates beta-amyloid (Aβ) plaque formation, but whether this is caused by APOE expressed in microglia or astrocytes is debated. We express here the human APOE isoforms in astrocytes in an Apoe-deficient AD mouse model. This is not only sufficient to restore the amyloid plaque pathology but also induces the characteristic transcriptional pathological responses in Apoe-deficient microglia surrounding the plaques. We find that both APOE4 and the protective APOE2 from astrocytes increase fibrillar plaque deposition, but differentially affect soluble Aβ aggregates. Microglia and astrocytes show specific alterations in function of APOE genotype expressed in astrocytes. Our experiments indicate a central role of the astrocytes in APOE mediated amyloid plaque pathology and in the induction of associated microglia responses. Synopsis: In the early phase of Alzheimer's disease, astrocytes are the primary source of APOE in the brain. This study examined the effects of astrocyte-derived human APOE isoforms in APOE-deficient mouse brains on amyloid pathology and related cellular responses. Apoe-deficient mouse brains: Displayed no fibrillar amyloid plaques and had increased levels of soluble Aβ aggregates. Human APOE isoforms in astrocytes: Expression in astrocytes alone induced formation of fibrillar amyloid plaques (APOE4 > APOE2 > APOE3) and reduced soluble Aβ aggregates (APOE2 > APOE4 ≈ APOE3). Astrocyte transcriptomics: APOE isoforms caused differential changes, suggesting possible impairment of proteostasis and autophagy in APOE4 astrocytes. Microglial response: Apoe-deficient microglia exhibited clustering and a DAM-like response to amyloid pathology induced by astrocyte-secreted APOE. Astrocyte-derived APOE and microglia: Astrocyte-derived APOE could induce fibrillar amyloid plaques even without the presence of microglia, although to a lesser extent. In the early phase of Alzheimer's disease, astrocytes are the primary source of APOE in the brain. This study examined the effects of astrocyte-derived human APOE isoforms in APOE-deficient mouse brains on amyloid pathology and related cellular responses. [ABSTRACT FROM AUTHOR]

The strongest risk factors for late-onset sporadic Alzheimer's disease (AD) include the ε4 allele of apolipoprotein E (APOE), the R47H variant of triggering receptor expressed on myeloid cells 2 (TREM2), and female sex. Here, we combine APOE4 and TREM2 R47H (R47H) in female P301S tauopathy mice to identify the pathways activated when AD risk is the strongest, thereby highlighting detrimental disease mechanisms. We find that R47H induces neurodegeneration in 9- to 10-month-old female APOE4 tauopathy mice. The combination of APOE4 and R47H (APOE4-R47H) worsened hyperphosphorylated tau pathology in the frontal cortex and amplified tauopathy-induced microglial cyclic guanosine monophosphate (GMP)-AMP synthase (cGAS)-stimulator of interferon genes (STING) signaling and downstream interferon response. APOE4-R47H microglia displayed cGAS- and BAX-dependent upregulation of senescence, showing association between neurotoxic signatures and implicating mitochondrial permeabilization in pathogenesis. By uncovering pathways enhanced by the strongest AD risk factors, our study points to cGAS-STING signaling and associated microglial senescence as potential drivers of AD risk. [Display omitted] • AD risk gene TREM2-R47H worsens tau-induced neurodegeneration in APOE4 female mice • TREM2-R47H increases tau pathology in the frontal cortex of APOE4 female mice • APOE4 and R47H amplify tau-induced microglial cGAS-STING and IFN-I in female mice • cGAS- and BAX-dependent microglial senescence is upregulated by APOE4 and R47H Carling et al. combine Alzheimer's disease (AD) risk factors APOE4 and R47H in a tauopathy model, uncovering amplification of microglial cGAS-STING, interferon, and cGAS-related senescence as disease-enhancing mechanisms in females. Their findings emphasize the importance of cGAS-dependent senescence as a potential driver of tauopathy in AD. [ABSTRACT FROM AUTHOR]

Familial dysbetalipoproteinemia (FD) is a highly atherogenic, prevalent genetically based lipid disorder. About 10% of FD patients have rare APOE variants associated with autosomal dominant FD. However, there are insufficient data on the relationship between rare APOE variants and FD. Genetic data from 4720 subjects were used to identify rare APOE variants and investigate their pathogenicity for autosomal dominant FD. We observed 24 variants in 86 unrelated probands. Most variants were unique (66.7%). Five identified APOE variants (p.Glu63ArgfsTer15, p.Gly145AlafsTer97, p.Lys164SerfsTer87, p.Arg154Cys, and p.Glu230Lys) are causal for autosomal dominant FD. One of them (p.Lys164SerfsTer87) was described for the first time. When we compared clinical data, it was found that carriers of pathogenic or likely pathogenic APOE variants had significantly higher triglyceride levels (median 5.01 mmol/L) than carriers of benign or likely benign variants (median 1.70 mmol/L, p = 0.034) and variants of uncertain significance (median 1.38 mmol/L, p = 0.036). For the first time, we estimated the expected prevalence of causal variants for autosomal dominant FD in the population sample: 0.27% (one in 619). Investigating the spectrum of APOE variants may advance our understanding of the genetic basis of FD and underscore the importance of APOE gene sequencing in patients with lipid metabolism disorders. [ABSTRACT FROM AUTHOR]

Alport syndrome (AS) is one of the most common inherited kidney disorders, involving pathogenic variants of COL4A3, COL4A4 and COL4A5 genes that lead to disruption of the normal structure of collagen IV protein through improper chain or heterotrimer folding or degradation of heterotrimer components. Lipoprotein glomerulopathy (LPG) is an autosomal dominant disease involving APOE gene mutations disturbing lipoprotein metabolism. We report the first case with both AS and LPG in an 11‐year‐old girl. The patient presented with blepharedema, and decreased vision. Laboratory examinations showed hematemesis, proteinuria, hypoproteinemia, hyperlipidemia and progressive renal failure. Renal biopsy showed the changes of LPG and AS. Whole‐exome sequencing (WES) identified two pathogenic variants, c.127C > T in exon 3 of APOE gene, and c.930 + 1G > A in exon 15 of COL4A4 gene. We emphasize the importance of early completion of renal biopsy and WES for early diagnosis of LPG and AS. [ABSTRACT FROM AUTHOR]

Lipoprotein glomerulopathy (LPG) is a rare disorder characterized by the development of glomerular lipoprotein thrombosis. LPG exhibits familial aggregation, with mutations in the apolipoprotein E (APOE) gene identified as the leading cause of this disease. This study aimed to investigate APOE gene mutations and the clinicopathological features in eleven LPG patients. Clinicopathological and follow-up data were obtained by extracting DNA, followed by APOE coding region sequencing analysis. This study analyzed clinical and pathological manifestations, gene mutations, treatment and prognosis. The mean age of the eleven patients was 33.82 years. Among them, five had a positive family history for LPG, ten presented with proteinuria, four exhibited nephrotic syndrome, and six presented with microscopic hematuria. Dyslipidemia was identified in ten patients. In all renal specimens, there was evident dilation of glomerular capillary lumens containing lipoprotein thrombi, and positive oil red O staining was observed in frozen sections of all samples. APOE gene testing revealed that one patient had no mutations, while the remaining ten patients exhibited mutations in the APOE gene, with three patients presenting with multiple mutations simultaneously. Following the confirmation of LPG diagnosis, treatment with angiotensin-converting enzyme inhibitor (ACEI)/angiotensin receptor blocker (ARB) was initiated, and the disease progressed slowly. LPG is histologically characterized by lamellated lipoprotein thrombi in glomeruli, and kidney biopsy is essential for diagnosis. Mutations in the APOE gene are the leading cause of LPG. This study revealed clinicopathological characteristics and APOE gene mutations in patients with LPG, which helps us better understand the disease. [ABSTRACT FROM AUTHOR]

Alzheimer's disease (AD) mouse models are indispensable tools to understand the regulatory mechanisms of AD pathogenesis and to evaluate the potential therapeutic strategies in preclinical studies, although they rarely recapitulate the entire spectrum of AD pathological features. Most of the commonly used AD mouse models are developed by overexpressing genetic mutations implicated in familial AD, which accounts for less than 1% of all AD cases, and these models represent an extreme condition that would not occur in human patients with AD. On the basis of multiple humanized sporadic AD genetic risk factors, novel mouse models have increasingly been developed in an attempt to capture the trajectory and progression of AD more accurately. Despite numerous advantages, AD mouse models have their intrinsic limitations in translating preclinical findings to human clinical trials. Alzheimer's disease (AD) poses a significant health challenge worldwide, and the development of effective treatments necessitates a comprehensive understanding of its pathophysiology. Mouse models have been instrumental in offering insights into the crucial pathogenesis of AD. However, current models rarely recapitulate all aspects of AD pathology in patients; thus, translating the findings from mouse to human clinical trials has proved to be complex. In this review, we outline the development of some prevalently used AD mice, with a particular emphasis on the latest advances in newly generated models. In addition, we discuss the advantages and limitations in mouse models of AD and their applications in blood-based biomarkers. Finally, we speculate on potential future research directions. [ABSTRACT FROM AUTHOR]

The gut microbiome has become increasingly recognized for its role in the pathogenesis of Alzheimer’s disease (AD) and is thought to influence AD pathogenesis via metabolic crosstalk with the host. However, mechanistic pathways connecting the gut microbiome to AD pathogenesis remain unknown. To explore potential mechanistic pathways in AD pathogenesis, we created host–microbiome whole-body metabolic models personalized with 16S rRNA microbiome data and predicted emergent metabolic contributions of gut microbiomes. We analyzed 63 metabolites in blood with previously known links with AD. These in silico predictions were then associated with major risk factors for AD in a cohort of 1,065 aging non-AD individuals and subsequently used to inform targeted analyses on serum metabolomics. Our analysis identified increased host-microbial production of L-arginine in older individuals. Lower production of deoxycholate correlated with the neuroprotective APOE E2 allele and it decreased with higher global cognition. Serum metabolomics from the same individuals of cholesterol products and bile acid metabolism corroborated the modeling predictions, suggesting a potential link between the APOE genotype and cognitive health. In conclusion, this study associated metabolic gut microbiome influences on human metabolism with risk factors for AD and identified cholesterol and bile acid metabolism to potentially link with AD pathogenesis.

BackgroundAPOE4 is the strongest genetic risk factor for sporadic Alzheimer's disease (AD), whereas APOE2 confers protection. However, effects of APOE on neurodegeneration in cognitively intact individuals, and how these associations evolve with cognitive decline, are unclear. Furthermore, few studies have evaluated whether effects of APOE on neurodegenerative changes are modified by other AD key risk factors including age and sex.MethodsParticipants included older adults (57% women; 77 ± 7 years) from the Rancho Bernardo Study of Health Aging and the University of California San Diego Alzheimer's Disease Research Center, including 192 cognitively normal (CN) individuals and 33 with mild cognitive impairment. Participants underwent diffusion MRI, and multicompartment restriction spectrum imaging (RSI) metrics were computed in white matter, gray matter, and subcortical regions of interest. Participants were classified as APOE4 carriers, APOE2 carriers, and APOE3 homozygotes. Analysis of covariance among CN (adjusting for age, sex, and scanner) assessed differences in brain microstructure by APOE, as well as interactions between APOE and sex. Analyses across all participants examined interactions between APOE4 and cognitive status. Linear regressions assessed APOE by age interactions.ResultsAmong CN, APOE4 carriers showed lower entorhinal cortex neurite density than non-carriers, whereas APOE2 carriers showed lower cingulum neurite density than non-carriers. Differences in entorhinal microstructure by APOE4 and in entorhinal and cingulum microstructure by APOE2 were present for women only. Age correlated with lower entorhinal restricted isotropic diffusion among APOE4 non-carriers, whereas age correlated with lower putamen restricted isotropic diffusion among APOE4 carriers. Differences in microstructure between cognitively normal and impaired participants were stronger for APOE4-carriers in medial temporal regions, thalamus, and global gray matter, but stronger for non-carriers in caudate.ConclusionsThe entorhinal cortex may be an early target of neurodegenerative changes associated with APOE4 in presymptomatic individuals, whereas APOE2 may support beneficial white matter and entorhinal microstructure, with potential sex differences that warrant further investigation. APOE modifies microstructural patterns associated with aging and cognitive impairment, which may advance the development of biomarkers to distinguish microstructural changes characteristic of normal brain aging, APOE-dependent pathways, and non-AD etiologies.

Abstract The major genetic risk factor for Alzheimer’s disease (AD), APOE4, accelerates beta-amyloid (Aβ) plaque formation, but whether this is caused by APOE expressed in microglia or astrocytes is debated. We express here the human APOE isoforms in astrocytes in an Apoe-deficient AD mouse model. This is not only sufficient to restore the amyloid plaque pathology but also induces the characteristic transcriptional pathological responses in Apoe-deficient microglia surrounding the plaques. We find that both APOE4 and the protective APOE2 from astrocytes increase fibrillar plaque deposition, but differentially affect soluble Aβ aggregates. Microglia and astrocytes show specific alterations in function of APOE genotype expressed in astrocytes. Our experiments indicate a central role of the astrocytes in APOE mediated amyloid plaque pathology and in the induction of associated microglia responses.

Youni Lin, Min Yang, Qifeng Liu, Yufu Cai, Zhouhua Zhang, Chongfei Xu, Ming Luo Center for Cardiovascular Diseases, Meizhou People’s Hospital, Meizhou, People’s Republic of ChinaCorrespondence: Youni Lin, Center for Cardiovascular Diseases, Meizhou People’s Hospital, Meizhou, People’s Republic of China, Email linyn2024@126.comBackground: Atherosclerosis is a systemic disease that can involve multiple vascular beds. The risk factors for atherosclerosis in multiple vascular beds remain unclear. Apolipoprotein E (APOE) is involved in inflammation and lipid deposition in the process of atherosclerosis. The objective of this study was to investigate whether APOE polymorphisms are associated with atherosclerosis in multiple vascular beds.Methods: A total of 416 patients with atherosclerosis in single vascular bed and 658 patients with atherosclerosis in multiple vascular beds were included. APOE genotypes were detected and the differences of APOE genotypes between the groups were compared. Logistic regression analysis was performed to analyze the relationship between APOE genotypes and atherosclerosis in multiple vascular beds.Results: APOE E3/E4 genotype frequency was lower in the patients with atherosclerosis in multiple vascular beds than that of patients with atherosclerosis in single vascular bed (11.4% vs 17.8%, P=0.004). There was no significant difference in age and gender distribution, proportion of history of smoking, alcohol consumption, hypertension, and diabetes mellitus between the two groups (all P> 0.05), and among patients with different APOE alleles (all P> 0.05). Logistic regression analysis indicated that APOE E3/E4 genotype (E3/E4 vs E3/E3: odds ratio (OR) 0.598, 95% confidence interval (CI): 0.419– 0.854, P=0.005), and APOE &epsiv;4 allele (&epsiv;4 vs &epsiv;3: OR 0.630, 95% CI: 0.444– 0.895, P=0.010) associated with atherosclerosis in multiple vascular beds.Conclusion: APOE &epsiv;4 allele is associated with atherosclerosis in multiple vascular beds.Keywords: APOE, polymorphism, atherosclerosis, multiple vascular beds

Abstract Background Apolipoprotein 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. Methods We 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. Results Analyses 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. Conclusions APOE 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.

Abstract Background There is initial evidence suggesting that biomarker neurogranin (Ng) may distinguish Alzheimer’s disease (AD) from other neurodegenerative diseases. Therefore, we assessed (a) the discriminant ability of cerebrospinal fluid (CSF) Ng levels to distinguish between AD and frontotemporal lobar degeneration (FTLD) pathology and between different stages within the same disease, (b) the relationship between Ng levels and cognitive performance in both AD and FTLD pathology, and (c) whether CSF Ng levels vary by apolipoprotein E (APOE) polymorphism in the AD continuum. Methods Participants with subjective cognitive decline (SCD) (n = 33), amnestic mild cognitive impairment (aMCI) due to AD (n = 109), AD dementia (n = 67), MCI due to FTLD (n = 25), and FTLD dementia (n = 29) were recruited from the Czech Brain Aging Study. One-way analysis of covariance (ANCOVA) assessed Ng levels in diagnostic subgroups. Linear regressions evaluated the relationship between CSF Ng levels, memory scores, and APOE polymorphism. Results Ng levels were higher in aMCI-AD patients compared to MCI-FTLD (F[1, 134] = 15.16, p

Abstract Objective Apolipoprotein E (APOE) gene polymorphisms were associated with coronary atherosclerosis and hypertension. However, the relationship between APOE polymorphisms and coronary atherosclerosis susceptibility in hypertensive patients is unclear. The aim of this study was to assess the relationship. Methods A total of 1713 patients with hypertension who were admitted to Meizhou People’s Hospital from November 2019 to August 2023 were retrospectively analyzed, including 848 patients with coronary atherosclerosis and 865 patients without coronary atherosclerosis. The rs429358 and rs7412 polymorphisms of APOE were genotyped, and relationship between APOE polymorphisms and the risk of coronary atherosclerosis in hypertensive patients were analyzed. Results There were 10 (0.6%), 193 (11.3%), 30 (1.8%), 1234 (72.0%), 233 (13.6%), and 13 (0.8%) individuals with APOE ɛ2/ɛ2, ɛ2/ɛ3, ɛ2/ɛ4, ɛ3/ɛ3, ɛ3/ɛ4, and ɛ4/ɛ4 genotype, respectively. The frequency of APOE ɛ3/ɛ4 was higher (16.4% vs. 10.9%, p = 0.001) in the patients with coronary atherosclerosis than controls. Logistic analysis showed that body mass index (BMI) ≥ 24.0 kg/m2 (24.0 kg/m2 vs. 18.5–23.9 kg/m2, odds ratio (OR): 1.361, 95% confidence interval (CI): 1.112–1.666, p = 0.003), advanced age (≥ 65/

Abstract Background Impulse control disorders (ICDs) are an increasingly recognized complication in Parkinson disease (PD). The pathogenesis of ICDs is currently unclear. Few genetic studies have been conducted in this area. Objective We aimed to ascertain the correlation between APOE and ICDs, and identify clinical predictors of ICDs in PD. Methods This study included 287 PD patients from the Parkinson’s Progression Markers Initiative. They were followed up to investigate the progression of ICDs over a period of 5 years. The cumulative incidence of ICDs and potential risk factors were evaluated using Kaplan-Meier and Cox regression analyses. Results 44.3% (31/70) patients with APOE ɛ4 and 32.3% (70/217) patients without APOE ɛ4 developed ICDs during the five-year follow up period. There were significant differences between the PD with and without ICDs development group in age, MSEADLG score, ESS score, GDS score, and STAI score at baseline. In multivariable Cox regression analysis, APOE ε4 (HR = 1.450, p = 0.048) and STAI score (HR = 1.017, p = 0.001) were predictors of the development of ICDs. Patients with APOE ɛ4 group showed significantly lower CSF Aβ42 and CSF α-syn level than patients without APOE ɛ4 group at baseline. In patients with APOE ɛ4 group, the “low α-syn level” group and the “low ptau/tau ratio” group had a significantly higher incidence of ICDs, respectively. Conclusions This study provides important insights into the potential role of the APOE gene in the development of ICDs in PD. Further studies are needed to confirm our findings and to investigate the underlying mechanisms in more detail.

Background: Genetic variations in a common single nucleotide polymorphism in the ninth intron of the KIBRA gene have been linked to memory performance and risk of Alzheimer's disease (AD). Objective: We examined the risk of AD related to presence of KIBRA T allele (versus CC homozygote) and to memory performance. The role of established genetic risk factors APOE ε4 and BDNF Met was also considered. Methods: Participants were cognitively healthy individuals (n = 19), participants with amnestic mild cognitive impairment (aMCI) due to AD (n = 99) and AD dementia (n = 37) from the Czech Brain Aging Study. Binary and multinomial logistic regressions compared odds of belonging to a certain diagnostic category and multivariate linear regressions assessed associations with memory. Results: KIBRA T allele was associated with increased AD dementia risk (odds ratio [OR] = 5.98, p = 0.012) compared to KIBRA CC genotype. In APOE ε4 negative individuals, KIBRA T allele was associated with a greater risk of both aMCI due to AD (OR = 6.68, p = 0.038) and AD dementia (OR = 15.75, p = 0.009). In BDNF Met positive individuals, the KIBRA T allele was associated with a greater risk of AD dementia (OR = 10.98, p = 0.050). In AD dementia, the association between KIBRA T allele and better memory performance approached significance (β = 0.42; p = 0.062). The link between possessing the KIBRA T allele and better memory reached statistical significance only among BDNF Met carriers (β = 1.21, p = 0.027). Conclusions: Findings suggest that KIBRA T allele may not fully protect against AD dementia but could potentially delay progression of post-diagnosis cognitive deficits. [ABSTRACT FROM AUTHOR]