Characterizing the Resilience Effect of Neurodegeneration for the Mechanistic Pathway of Alzheimer’s Disease

2021 ◽  
pp. 1-12
Author(s):  
Di Hu ◽  
Chuning Liu ◽  
Kai Xia ◽  
Amy Abramowitz ◽  
Guorong Wu ◽  
...  

Background: With the rapid development of neurobiology and neuroimaging technologies, mounting evidence shows that Alzheimer’s disease (AD) is caused by the build-up of two abnormal proteins, amyloid-β plaques (A) and neurofibrillary tangles (T). Over time, these AD-related neuropathological burdens begin to spread throughout the brain, which results in the characteristic progression of symptoms in AD. Objective: Although tremendous efforts have been made to link biological indicators to the progression of AD, limited attention has been paid to investigate the multi-factorial role of socioeconomic status (SES) in the prevalence or incidence of AD. There is high demand to explore the synergetic effect of sex and SES factors in moderating the neurodegeneration process caused by the accumulation of A and T biomarkers. Methods: We carry out a meta-data analysis on the longitudinal neuroimaging data, clinical outcomes, genotypes, and demographic data in Alzheimer’s Disease Neuroimaging Initiative (ADNI) database (http://adni.loni.usc.edu). Results: Our major findings include 1) education and occupation show resilience effects at the angular gyrus, superior parietal lobule, lateral occipital-temporal sulcus, and posterior transverse collateral sulcus where we found significant slowdown of neurodegeneration due to higher education level or more advanced occupation rank; 2) A and T biomarkers manifest different spatial patterns of brain resilience; 3) BDNF (brain-derived neurotrophic factor) single nucleotide polymorphism (SNP) rs10835211 shows strong association to the identified resilience effect; 4) the identified resilience effect is associated with the clinical manifestation in memory, learning, and organization performance. Conclusion: Several brain regions manifest resilience from SES to A and T biomarkers. BDNF SNPs have a potential association with the resilience effect from SES. In addition, cognitive measures of learning and memory demonstrate the resilience effect.

2021 ◽  
pp. 1-19
Author(s):  
Mario Tombini ◽  
Giovanni Assenza ◽  
Lorenzo Ricci ◽  
Jacopo Lanzone ◽  
Marilisa Boscarino ◽  
...  

Increasing evidence coming from both experimental and humans’ studies strongly suggest the existence of a link between epilepsy, in particular temporal lobe epilepsy (TLE), and Alzheimer’s disease (AD). Patients with mild cognitive impairment and AD are more prone to have seizures, and seizures seem to facilitate amyloid-β and tau deposits, thus promoting neurodegenerative processes. Consistent with this view, long-lasting drug-resistant TLE and AD have been shown to share several pathological and neuroimaging features. Even if studies addressing prevalence of interictal and subclinical epileptiform activity in these patients are not yet conclusive, their findings raise the possibility that epileptiform activity might negatively impact memory and hasten cognitive decline, either directly or by association with unrecognized silent seizures. In addition, data about detrimental effect of network hyperexcitability in temporal regions in the premorbid and early stages ofADopen up newtherapeutic opportunities for antiseizure medications and/or antiepileptic strategies that might complement or enhance existing therapies, and potentially modify disease progression. Here we provide a review of evidence linking epileptiform activity, network hyperexcitability, and AD, and their role promoting and accelerating neurodegenerative process. Finally, the effects of antiseizure medications on cognition and their optimal administration in patients with AD are summarized.


Author(s):  
Yusra Mansour ◽  
Kaitlyn Blackburn ◽  
Luis Oscar González-González ◽  
Lilian Calderón-Garcidueñas ◽  
Randy J. Kulesza

Alzheimer’s disease (AD) is a biological construct defined by abnormal deposits of hyperphosphorylated tau and amyloid-β. The 2050 projection for AD in the USA is 14 million. There is a strong association between AD, air pollution, and traffic. Early diagnosis is imperative for intervention in the initial disease stages. Hearing and, specifically, the ability to encode complex sounds are impaired in AD. Nuclei in the auditory brainstem appear to be sensitive to neurodevelopmental and neurodegenerative disorders. Specifically, sustained exposure to air pollution is harmful to the brainstem; young residents of Metropolitan Mexico City (MMC) exposed to fine particulate matter and combustion-derived nanoparticles develop AD pathology in infancy. MMC clinically healthy children and teens have significant central delays in brainstem auditory evoked potentials (BAEPs). Herein, we review evidence that the auditory pathway is a key site of AD early pathology associated with air pollution and is significantly involved in AD patients. We strongly suggest electrophysiological screening, including BAEPs, be employed to screen individuals for early delays and to monitor progressive decline in patients diagnosed with mild cognitive impairment and AD. Understanding auditory dysfunction in early AD in pediatric and young adult populations may clarify mechanisms of disease progression. Air pollution is a risk factor for the development of AD and as the number of Americans with AD continues to grow without a cure, we need to focus on preventable, early causes of this fatal disease and intervene appropriately.


2021 ◽  
Vol 13 ◽  
Author(s):  
Li Lin ◽  
Yu Sun ◽  
Xiaoqi Wang ◽  
Li Su ◽  
Xiaoni Wang ◽  
...  

Objective: To define resilience metrics for cognitive decline based on plasma and cerebrospinal fluid (CSF) amyloid-β (Aβ) and examine the demographic, genetic, and neuroimaging factors associated with interindividual differences among metrics of resilience and to demonstrate the ability of such metrics to predict the diagnostic conversion to mild cognitive impairment (MCI).Methods: In this study, cognitively normal (CN) participants with Aβ-positive were included from the Sino Longitudinal Study on Cognitive Decline (SILCODE, n = 100) and Alzheimer's Disease Neuroimaging Initiative (ADNI, n = 144). Using a latent variable model of data, metrics of resilience [brain resilience (BR), cognitive resilience (CR), and global resilience (GR)] were defined based on the plasma Aβ and CSF Aβ. Linear regression analyses were applied to investigate the association between characteristics of individuals (age, sex, educational level, genetic, and neuroimaging factors) and their resilience. The plausibility of these metrics was tested using linear mixed-effects models and Cox regression models in longitudinal analyses. We also compared the effectiveness of these metrics with conventional metrics in predicting the clinical progression.Results: Although individuals in the ADNI cohort were older (74.68 [5.65] vs. 65.38 [4.66], p < 0.001) and had higher educational levels (16.3 [2.6] vs. 12.6 [2.8], p < 0.001) than those in the SILCODE cohort, similar loadings between resilience and its indicators were found within both models. BR and GR were mainly associated with age, women, and brain volume in both cohorts. Prediction models showed that higher CR and GR were related to better cognitive performance, and specifically, all types of resilience to CSF Aβ could predict longitudinal cognitive decline.Conclusion: Different phenotypes of resilience depending on cognition and brain volumes were associated with different factors. Such comprehensive resilience provided insight into the mechanisms of susceptibility for Alzheimer's disease (AD) at the individual level, and interindividual differences in resilience had the potential to predict the disease progression in CN people.


2020 ◽  
Author(s):  
Chunmei Bian ◽  
Wei Li ◽  
Liping Wang ◽  
Zhenzhen Long ◽  
Ping Xue ◽  
...  

Abstract Backgrounnd: The impact of Alzheimer's disease (AD) on the living quality and life expectancy has becoming increasingly severe, but the pathogenesis of AD is still being studied .This study aimed to investigate whether Family with sequence similarity 3 member C (FAM3C), which has been reported to be possibly associated with cognitive function, was associated with the incidence of AD.Methods: A total of 282 participants from Alzheimer’s Disease Neuroimaging Initiative (ADNI) were included. The demographic data, cerebrospinal fluid (CSF) FAM3C content, neuropsychological scores, CSF amyloid protein level, CSF tau protein level, and imaged data were collected. One-way analysis of variance and chi-square test were used to compare demographic data, neuropsychological test scores, CSF protein levels, and imaging data of three groups. Partial correlation analysis and multiple linear regression analysis were used to investigate the relationship between FAM3C and AD diagnostic indicators in different dimensions. An ordered multi-classification logistic regression model was established to determine whether FAM3C is related to the onset of AD. Results: Lower levels of FAM3C were observed in AD and mild cognitive impairment (MCI) groups. CSF FAM3C level was related to whole-brain atrophy and temporal lobe atrophy, worse cognitive performance, decreased amyloid β 1-42 (Aβ1-42), and lower regional cerebral glucose metabolism. Conclusion: CSF FAM3C might be a potential diagnostic biomarker of AD. Further study on concrete mechanisms may contribute to early diagnosis and treatment of AD.


2014 ◽  
Vol 56 ◽  
pp. 99-110 ◽  
Author(s):  
David Allsop ◽  
Jennifer Mayes

One of the hallmarks of AD (Alzheimer's disease) is the formation of senile plaques in the brain, which contain fibrils composed of Aβ (amyloid β-peptide). According to the ‘amyloid cascade’ hypothesis, the aggregation of Aβ initiates a sequence of events leading to the formation of neurofibrillary tangles, neurodegeneration, and on to the main symptom of dementia. However, emphasis has now shifted away from fibrillar forms of Aβ and towards smaller and more soluble ‘oligomers’ as the main culprit in AD. The present chapter commences with a brief introduction to the disease and its current treatment, and then focuses on the formation of Aβ from the APP (amyloid precursor protein), the genetics of early-onset AD, which has provided strong support for the amyloid cascade hypothesis, and then on the development of new drugs aimed at reducing the load of cerebral Aβ, which is still the main hope for providing a more effective treatment for AD in the future.


Author(s):  
Mingeun Kim ◽  
Juhye Kang ◽  
Misun Lee ◽  
Jiyeon Han ◽  
Geewoo Nam ◽  
...  

We report a minimalistic redox-based design strategy for engineering compact molecules based on the simplest aromatic framework, benzene, with multi-reactivity against free radicals, metal-free amyloid-β, and metal-bound amyloid-β, implicated in the most common form of dementia, Alzheimer’s disease.


2013 ◽  
Vol 10 (2) ◽  
pp. 165-173 ◽  
Author(s):  
Zdena Kristofikova ◽  
Daniela Ripova ◽  
Ales Bartos ◽  
Marketa Bockova ◽  
Katerina Hegnerova ◽  
...  

2020 ◽  
Vol 17 (1) ◽  
pp. 29-43 ◽  
Author(s):  
Patrick Süß ◽  
Johannes C.M. Schlachetzki

: Alzheimer’s Disease (AD) is the most frequent neurodegenerative disorder. Although proteinaceous aggregates of extracellular Amyloid-β (Aβ) and intracellular hyperphosphorylated microtubule- associated tau have long been identified as characteristic neuropathological hallmarks of AD, a disease- modifying therapy against these targets has not been successful. An emerging concept is that microglia, the innate immune cells of the brain, are major players in AD pathogenesis. Microglia are longlived tissue-resident professional phagocytes that survey and rapidly respond to changes in their microenvironment. Subpopulations of microglia cluster around Aβ plaques and adopt a transcriptomic signature specifically linked to neurodegeneration. A plethora of molecules and pathways associated with microglia function and dysfunction has been identified as important players in mediating neurodegeneration. However, whether microglia exert either beneficial or detrimental effects in AD pathology may depend on the disease stage. : In this review, we summarize the current knowledge about the stage-dependent role of microglia in AD, including recent insights from genetic and gene expression profiling studies as well as novel imaging techniques focusing on microglia in human AD pathology and AD mouse models.


2018 ◽  
Vol 15 (4) ◽  
pp. 386-398 ◽  
Author(s):  
Fabricio Ferreira de Oliveira ◽  
Elizabeth Suchi Chen ◽  
Marilia Cardoso Smith ◽  
Paulo Henrique Ferreira Bertolucci

Background: While the angiotensin-converting enzyme degrades amyloid-β, angiotensinconverting enzyme inhibitors (ACEis) may slow cognitive decline by way of cholinergic effects, by increasing brain substance P and boosting the activity of neprilysin, and by modulating glucose homeostasis and augmenting the secretion of adipokines to enhance insulin sensitivity in patients with Alzheimer’s disease dementia (AD). We aimed to investigate whether ACE gene polymorphisms rs1800764 and rs4291 are associated with cognitive and functional change in patients with AD, while also taking APOE haplotypes and anti-hypertensive treatment with ACEis into account for stratification. Methods: Consecutive late-onset AD patients were screened with cognitive tests, while their caregivers were queried for functional and caregiver burden scores. Prospective pharmacogenetic correlations were estimated for one year, considering APOE and ACE genotypes and haplotypes, and treatment with ACEis. Results: For 193 patients, minor allele frequencies were 0.497 for rs1800764 – C (44.6% heterozygotes) and 0.345 for rs4291 – T (38.9% heterozygotes), both in Hardy-Weinberg equilibrium. Almost 94% of all patients used cholinesterase inhibitors, while 155 (80.3%) had arterial hypertension, and 124 used ACEis. No functional impacts were found regarding any genotypes or pharmacological treatment. Either for carriers of ACE haplotypes that included rs1800764 – T and rs4291 – A, or for APOE4- carriers of rs1800764 – T or rs4291 – T, ACEis slowed cognitive decline independently of blood pressure variations. APOE4+ carriers were not responsive to treatment with ACEis. Conclusion: ACEis may slow cognitive decline for patients with AD, more remarkably for APOE4- carriers of specific ACE genotypes.


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