scholarly journals The Apolipoprotein E Antagonistic Pleiotropy Hypothesis: Review and Recommendations

2011 ◽  
Vol 2011 ◽  
pp. 1-12 ◽  
Author(s):  
Elizabeth R. Tuminello ◽  
S. Duke Han

Research on apolipoprotein E (APOE) has consistently revealed a relationship between the gene'sε4 allele and risk for development of Alzheimer's disease (AD). However, research with younger populations ofε4 carriers has suggested that the APOEε4 allele may in fact be beneficial in earlier ages and may only confer risk of cognitive decline later in life. Accordingly, we and others have proposed that APOE may represent an example of antagonistic pleiotropy. Antagonistic pleiotropy is an evolutionary biology concept that proposes certain genes or alleles that may differentially impact fitness during different life stages. We critically review this hypothesis in light of new research of the impact of APOE on cognition and neural integrity across the lifespan. We provide recommendations for the revision of the antagonistic pleiotropy hypothesis of APOE and suggest important avenues for future research in this area.

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Céline H. De Jager ◽  
Charles C. White ◽  
David A. Bennett ◽  
Yiyi Ma

AbstractAccumulating evidence has suggested that the molecular transcriptional mechanism contributes to Alzheimer’s disease (AD) and its endophenotypes of cognitive decline and neuropathological traits, β-amyloid (Aβ) and phosphorylated tangles (TAU). However, it is unknown what is the impact of the AD risk factors, personality characteristics assessed by the NEO Five-Factor Inventory, on the human brain’s transcriptome. Using postmortem human brain samples from 466 subjects, we found that neuroticism has a significant overall impact on the brain transcriptome (omnibus P = 0.005) but not the other four personality characteristics. Focused on those cognitive decline related gene co-expressed modules, neuroticism has nominally significant associations (P < 0.05) with four neuronal modules, which are more related to PHFtau than Aβ across all eight brain regions. Furthermore, the effect of neuroticism on cognitive decline and AD might be mediated through the expression of module 7 and TAU pathology (P = 0.008). To conclude, neuroticism has a broad impact on the transcriptome of human brains, and its effect on cognitive decline and AD may be mediated through gene transcription programs related to TAU pathology.


2021 ◽  
Vol 13 (1) ◽  
Author(s):  
Ling-Zhi Ma ◽  
Hao Hu ◽  
Zuo-Teng Wang ◽  
Ya-Nan Ou ◽  
Qiang Dong ◽  
...  

Abstract Background There are many pathological changes in the brains of Alzheimer’s disease (AD) patients. For many years, the mainstream view on the pathogenesis of AD believes that β-amyloid (Aβ) usually acts independently in addition to triggering functions. However, the evidence now accumulating indicates another case that these pathological types have synergies. The objective of this study was to investigate whether effects of Aβ pathology on cognition were mediated by AD pathologies, including tau-related pathology (p-tau), neurodegeneration (t-tau, MRI measurements), axonal injury (NFL), synaptic dysfunction (neurogranin), and neuroinflammation (sTREM2, YKL-40). Methods Three hundred seventy normal controls (CN) and 623 MCI patients from the ADNI (Alzheimer’s Disease Neuroimaging Initiative) database were recruited in this research. Linear mixed-effects models were used to evaluate the associations of baseline Aβ with cognitive decline and biomarkers of several pathophysiological pathways. Causal mediation analyses with 10,000 bootstrapped iterations were conducted to explore the mediation effects of AD pathologies on cognition. Results Tau-related pathology, neurodegeneration, neuroinflammation are correlated with the concentration of Aβ, even in CN participants. The results show that age, gender, and APOE ε4 carrier status have a moderating influence on some of these relationships. There is a stronger association of Aβ with biomarkers and cognitive changes in the elderly and females. In CN group, Aβ pathology is directly related to poor cognition and has no mediating effect (p < 0.05). In mild cognitive impairment, tau-related pathology (26.15% of total effect) and neurodegeneration (14.8% to 47.0% of total effect) mediate the impact of Aβ on cognition. Conclusions In conclusion, early Aβ accumulation has an independent effect on cognitive decline in CN and a tau, neurodegeneration-dependent effect in the subsequent cognitive decline in MCI patients.


Author(s):  
Darby Morhardt ◽  
Marcia Spira

When a member of a family is diagnosed with Alzheimer's disease, the impact of the disease reverberates throughout the relationships within the family. This paper explores the challenges and strengths within one family as members manage and cope with Alzheimer's disease. The person with dementia and his family members are individually interviewed and each person explores the consequences of the disease on personal well-being as well as the relationships within the family. The family demonstrates how dementia in one family member demands flexibility in family roles as they navigate life through the challenges of living with dementia.


Neurology ◽  
1996 ◽  
Vol 47 (2) ◽  
pp. 317-320 ◽  
Author(s):  
B. L. Plassman ◽  
J. C.S. Breitner

2019 ◽  
Vol 15 ◽  
pp. P701-P701
Author(s):  
Kazushi Suzuki ◽  
Ryoko Ihara ◽  
Takeshi Ikeuchi ◽  
Atsushi Iwata ◽  
Takeshi Iwatsubo

2020 ◽  
Vol 78 (2) ◽  
pp. 573-585
Author(s):  
Hyemin Jang ◽  
Hee Jin Kim ◽  
Yeong Sim Choe ◽  
Soo-Jong Kim ◽  
Seongbeom Park ◽  
...  

Background: As Alzheimer’s disease (AD) and cerebral small vessel disease (CSVD) commonly coexist, the interaction between two has been of the considerable interest. Objective: We determined whether the association of Aβ and tau with cognitive decline differs by the presence of significant CSVD. Methods: We included 60 subcortical vascular cognitive impairment (SVCI) from Samsung Medical Center and 82 Alzheimer’s disease-related cognitive impairment (ADCI) from ADNI, who underwent Aβ (florbetaben or florbetapir) and tau (flortaucipir, FTP) PET imaging. They were retrospectively assessed for 5.0±3.9 and 5.6±1.9 years with Clinical Dementia Rating-sum of boxes (CDR-SB)/Mini-Mental State Examination (MMSE). Mixed effects models were used to investigate the interaction between Aβ/tau and group on CDR-SB/MMSE changes. Results: The frequency of Aβ positivity (45% versus 54.9%, p = 0.556) and mean global FTP SUVR (1.17±0.21 versus 1.16±0.17, p = 0.702) were not different between the two groups. We found a significant interaction effect of Aβ positivity and SVCI group on CDR-SB increase/MMSE decrease (p = 0.013/p < 0.001), and a significant interaction effect of global FTP uptake and SVCI group on CDR-SB increase/MMSE decrease (p < 0.001 and p = 0.030). Finally, the interaction effects of regional tau and group were prominent in the Braak III/IV (p = 0.001) and V/VI (p = 0.003) not in Braak I/II region (p = 0.398). Conclusion: The association between Aβ/tau and cognitive decline is stronger in SVCI than in ADCI. Therefore, our findings suggested that Aβ positivity or tau burden (particularly in the Braak III/IV or V/VI regions) and CSVD might synergistically affect cognitive decline.


2021 ◽  
Vol 36 (6) ◽  
pp. 1044-1044
Author(s):  
Claire Alexander ◽  
Julie Suhr

Abstract Objective Little research has focused on possible effects of TBI on cognitive decline rate after Alzheimer’s disease (ad) diagnosis. We examined whether Apolipoprotein E (APOE) status and TBI history interact to predict cognitive decline. Method We used data from the National Alzheimer’s Coordinating Centers (N = 463; 42.3% APOE e4 carriers, 7.8% with TBI history, mean baseline age 79.3). Inclusion criteria included normal cognition at baseline with diagnosis of ad at a follow-up visit; baseline age 50 or older; and at least 3 years of follow-up data. Mixed models (random intercept, random slope) were used, with TBI history, APOE status, and their interaction as predictors of interest. Education, race, and history of TIA, stroke, or hypertension were included as covariates. Cognitive measures included mental status exam scores and immediate/delayed story memory. Results After accounting for covariates, TBI history had a positive effect on cognitive decline rate on the screener and immediate memory measures. APOE status did not affect rate of cognitive decline on the screener, but presence of e4 predicted faster decline on immediate and delayed memory. TBI history and APOE status interacted to predict delayed memory decline, such that history of TBI was associated with a reduced rate of decline for e4 non-carriers but there was no effect of TBI for e4 carriers. Conclusion When examining cognitive decline trajectory, TBI history predicted slower decline (a positive effect) while APOE had either a negative impact or no effect, depending on the measure. Future study should examine cognitive decline in the context of demographic and genetic factors.


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