Exercise as Potential Therapeutic Target to Modulate Alzheimer's Disease Pathology in APOE ε4 Carriers: A Systematic Review

Assessing the cardioprotective effects of exercise in APOE mouse models using deep learning and photon-counting micro-CT

BACKGROUND

The allelic variations of the apolipoprotein E (APOE) gene play a critical role in regulating lipid metabolism and significantly impact cardiovascular disease risk (CVD). This study aimed to evaluate the impact of exercise on cardiac structure and function in mouse models expressing different APOE genotypes using photon-counting computed tomography (PCCT) and deep learning-based segmentation.

METHODS

A total of 140 mice were grouped based on APOE genotype (APOE2, APOE3, APOE4), sex, and exercise regimen. All mice were maintained on a controlled diet to isolate the effects of exercise. Low dose cardiac photon counting micro-CT imaging with intrinsic gating was performed using a custom-built micro-PCCT system and data was reconstructed with an iterative algorithm incorporating both temporal and spectral dimensions. A liposomal-iodine nanoparticle contrast agent was intravenously administered to uniformly opacify cardiovascular structures. Cardiac structures were segmented using a 3D U-Net deep learning model that was trained and validated on manually labeled data. Statistical analyses, including ANOVA, post-hoc analysis, and stratified group comparisons, were used to assess the effects of genotype, sex, and exercise on key cardiac metrics, including ejection fraction and cardiac index.

RESULTS

The PCCT imaging pipeline provided high-resolution images with enhanced contrast between blood compartment and myocardium allowing for precise segmentation of cardiac features. Deep learning-based segmentation achieved high accuracy with an average Dice coefficient of 0.85. Exercise significantly improved cardiac performance, with ejection fraction increasing by up to 18% and cardiac index by 46% in exercised males, who generally benefited more from exercise. Females, particularly those with the APOE4 genotype, also showed improvements, with a 31% higher ejection fraction in exercised versus non-exercised mice. Stratified analyses confirmed that both sexes benefited from exercise, with males showing larger effect sizes. APOE3 and APOE4 genotypes derived the greatest benefit, while APOE2 mice showed no significant improvement.

CONCLUSIONS

This study demonstrates the utility of PCCT combined with deep learning segmentation in assessing the cardioprotective effects of exercise in APOE mouse models. These findings highlight the importance of genotype-specific approaches in understanding and potentially mitigating the impact of CVD through lifestyle interventions such as exercise.

HIV-associated neurocognitive disorders (HAND): Optimal diagnosis, antiviral therapy, pharmacological treatment, management, and future scopes

In the context of HIV infection, HIV-associated neurocognitive disorders (HAND) have become a serious concern. An extensive summary of the diagnosis, care, and mental health consequences related to HAND is given in this article. The diagnosis of HAND entails a multimodal approach that includes neuroimaging, cognition tests, and clinical examinations. Numerous screening instruments and standardized evaluations have been created to support the early identification and tracking of HAND. Appropriate actions and individualized treatment plans are made possible by prompt diagnosis. A multidisciplinary approach is used in the treatment of HAND, aiming to address various elements of cognitive impairment. The main stream of treatment is still antiretroviral medication (ART), which successfully lowers viral loads and stops further neurocognitive deterioration. Adjunctive treatments are essential for treating cognitive symptoms and improving overall quality of life. These therapies include cognitive rehabilitation, pharmaceutical interventions, and psychological support. Our knowledge of the pathophysiology of HAND has improved with the identification of the inflammatory milieu and persistent viral persistence in the central nervous system (CNS), which has also aided in the creation of biomarkers for CNS illness. Although biomarkers show inflammation, neuronal damage, and monocyte activity, their clinical use is still restricted. Although new techniques to treating HAND have been developed as a result of a better knowledge of pathogenic processes, the best course of action is still unknown.

Effects of a 6-month dual-task, power-based exercise program on cognitive function, neurological and inflammatory markers in older adults: secondary analysis of a cluster randomised controlled trial

Functional power-based exercise training can improve physical performance in older adults and cognitive training can improve measures of cognition, but their combined effects on cognition and related risk factors (neurological and inflammatory markers) remains uncertain. This 6-month cluster randomised controlled trial evaluated the effectiveness of dual-task functional power training (DT-FPT) on cognition and circulating neurological and inflammatory markers in older adults at increased falls risk, and whether intervention responses varied by apolipoprotein-E (ApoE) and brain derived neurotrophic factor (BDNF) polymorphisms. Three hundred residents aged ≥ 65 years at increased falls risk residing in 22 independent-living retirement communities, were randomised by village, to DT-FPT (n = 156, 11 villages) involving a multi-component power-based training program performed simultaneously with cognitive and/or motor tasks (45-60 min, 2/week), or a usual care control (CON) group (n = 144, 11 villages). Cognition (computerized CogState battery), inflammatory cytokines, BDNF, insulin-like growth factor-1, vascular endothelial growth factor, amyloid β (1-40) and (1-42) were assessed at baseline and 6-months. Overall, 233 (78%) participants completed the intervention and adherence averaged 50.1%. DT-FPT led to a net 0.18-0.20 SD benefit versus CON in psychomotor ability/attention and reaction time/attention (both P < 0.05). There were no significant intervention effects on circulating markers, except for a net 10.5% benefit in amyloid β (1-40) in DT-FPT versus CON (P < 0.05). Responses were not influenced by APOE or BDNF genotype. In conclusion, DT-FPT in older adults at increased falls risk can provide some cognitive benefits, but these were not related to corresponding changes in inflammatory or neurological markers or influenced by genotype. Australian New Zealand Clinical Trials Registry (ACTRN12613001161718). http://www.anzctr.org.au/ This project was funded by a grant from the National Health and Medical Research Council (NHMRC) Project (APP1046267).

Modulating effects of fitness and physical activity on Alzheimer's disease: Implications from a six-month randomized controlled sports intervention

BACKGROUND

Physical activity and fitness are major targets in Alzheimer's disease (AD) preventive research. However, current research is heterogeneous and often disregards the relationship between these parameters and disease outcomes.

OBJECTIVE

To assess the effects of physical activity and fitness on AD within the context of a multicomponent sports intervention.

METHODS

46 participants with early-stage AD (mean age 70 ± 7 years, 18 women, mean Montreal Cognitive Assessment (MoCA) score 19±5) were included in a six-month randomized controlled trial (Dementia-MOVE), participating in either a multicomponent sports intervention or a control condition with a psychoeducational program. The modulating effect of fitness and physical activity changes on AD outcome parameters such as cognition, function and cerebral brain structure from 3T-MRI were examined using multiple linear regression analyses.

RESULTS

An increase in VO2max was associated with assignment to the intervention group (p = 0.016), lower baseline fitness (p = 0.001), and an increased rate of physical activity (p = 0.046). Only in the intervention group, ΔVO2max had a beneficial modulating effect on the MoCA score (p = 0.039), the executive functions (p = 0.017) and regional brain volumes of the temporal lobe, e.g., the hippocampus (p = 0.044). High daily step count was associated with preserved executive functions (p = 0.001), and caregivers' quality of life (p ≤ 0.001) in the overall sample.

CONCLUSIONS

Our results confirm that multicomponent exercise improves cardiorespiratory fitness in AD, which is associated with advantageous developments in cognitive performance and preservation of brain structure. These findings suggest that especially patients with comparably worse cognition and fitness benefit and should be encouraged for activity engagement.

Role of astrocytes in Alzheimer's disease pathogenesis and the impact of exercise-induced remodeling

Alzheimer's disease (AD) is a prevalent and debilitating brain disorder that worsens progressively with age, characterized by cognitive decline and memory impairment. The accumulation of amyloid-beta (Aβ) leading to amyloid plaques and hyperphosphorylation of Tau, resulting in intracellular neurofibrillary tangles (NFTs), are primary pathological features of AD. Despite significant research investment and effort, therapies targeting Aβ and NFTs have proven limited in efficacy for treating or slowing AD progression. Consequently, there is a growing interest in non-invasive therapeutic strategies for AD prevention. Exercise, a low-cost and non-invasive intervention, has demonstrated promising neuroprotective potential in AD prevention. Astrocytes, among the most abundant glial cells in the brain, play essential roles in various physiological processes and are implicated in AD initiation and progression. Exercise delays pathological progression and mitigates cognitive dysfunction in AD by modulating astrocyte morphological and phenotypic changes and fostering crosstalk with other glial cells. This review aims to consolidate the current understanding of how exercise influences astrocyte dynamics in AD, with a focus on elucidating the molecular and cellular mechanisms underlying astrocyte remodeling. The review begins with an overview of the neuropathological changes observed in AD, followed by an examination of astrocyte dysfunction as a feature of the disease. Lastly, the review explores the potential therapeutic implications of exercise-induced astrocyte remodeling in the context of AD.

APOE ε4 carrier status moderates the effect of lifestyle factors on cognitive reserve

INTRODUCTION

This study examines the role of lifestyle factors in cognitive reserve among older adults, focusing on the moderating effect of apolipoprotein E (APOE) ε4 status.

METHODS

Data from 157 participants aged 45 and older from the Healthy Brain Initiative (HBI) were analyzed. Cognitive reserve was estimated using residual scores from Cognivue Clarity tests after accounting for brain atrophy and white matter hyperintensities (WMHs). Lifestyle factors included education, occupational attainment, physical activity, social engagement, diet, and mindfulness. Structural equation models were conducted to assess interactions.

RESULTS

Significant interactions were found between APOE ε4 status and mindfulness and social engagement on cognitive reserve, indicating stronger associations for APOE ε4 carriers.

DISCUSSION

APOE ε4 carriers may benefit more from certain lifestyle factors, potentially through stress reduction and anti-inflammatory pathways. These findings support integrating APOE ε4 genetic screening into personalized prevention strategies to enhance interventions aimed at preserving cognitive function and delaying dementia onset in at-risk populations.

HIGHLIGHTS

Mindfulness and social engagement have increased cognitive reserve in APOE ε4 carriers. Study uses residual scores from Cognivue Clarity tests to estimate cognitive reserve. APOE ε4 carriers show stronger associations with certain lifestyle factors on cognitive reserve. Personalized interventions could enhance cognitive resilience in genetically at-risk populations. Comprehensive assessment of multiple lifestyle factors highlights targeted intervention benefits.

Impact of physical activity, physical fitness and exercises on cognitive impairment in patients with multiple sclerosis: A review of evidence and underlying mechanisms

Cognitive impairment in persons with MS (pwMS) occurs commonly, early and independently of other clinical features of the disease. MS-related cognitive impairment is mainly characterized by weakening of information processing speed, working memory and episodic memory. Much evidence, based on both neuropsychological and neuroimaging outcomes, highlights successful cognitive rehabilitation interventions. In this context, promotion of physical activity and exercise training could be a dual, motor and cognitive, rehabilitation method. The aim of this article is, firstly, to review existing evidence regarding the effects of exercise on cognition among pwMS, and secondly, to explore the possible mechanisms of action of the cognitive-motor coupling.

Alzheimer's disease prevention: Apolipoprotein e4 moderates the effect of physical activity on brain beta-amyloid deposition in healthy older adults

OBJECTIVES

To investigate if higher baseline physical activity levels are associated with less β-amyloid burden and whether the ApoE4 genotype moderates this association cross-sectionally and longitudinally.

DESIGN

Prospective cohort study.

METHODS

204 cognitively normal older adults (74.5 ± 6.6 years; 26 % ApoE4-carrier) were analyzed. Baseline physical activity was measured using the Minnesota Physical Activity Questionnaire. Brain β-amyloid burden was measured with positron emission tomography using 11C-labeled Pittsburgh compound. A subsample of 128 participants underwent longitudinal positron emission tomography (2.0 ± 0.9 scans over 5 ± 3 years). Statistical analysis was run according to physical activity (high/low group) and the ApoE4 genotype (carrier/noncarrier).

RESULTS

The ApoE4 genotype moderated the relationship between physical activity and β-amyloid, such that low physical activity had a greater impact on β-amyloid deposition in ApoE4-carriers than noncarriers. This ApoE4 × physical activity effect on brain β-amyloid deposition was also observed when all available β-amyloid scan timepoints were included in the model. β-amyloid deposition increased over time (p < 0.001), and ApoE4-carriers had disproportionately greater β-amyloid accumulation than ApoE4-noncarriers. The lower physical activity group had marginally greater β-amyloid accumulation than the higher physical activity group (p = 0.099), but there was no significant ApoE4 effect on β-amyloid accumulation.

CONCLUSIONS

Low physical activity in combination with the ApoE4-carrier genotype is associated with increased β-amyloid burden, suggesting that ApoE4 moderates the effect of physical activity on β-amyloid load. However, this effect was insufficient for baseline physical activity to modulate the change in β-amyloid accumulation over time.

The Intersection of cerebral cholesterol metabolism and Alzheimer's disease: Mechanisms and therapeutic prospects

Alzheimer's disease (AD) is a common neurodegenerative disease in the elderly, the exact pathogenesis of which remains incompletely understood, and effective preventive and therapeutic drugs are currently lacking. Cholesterol plays a vital role in cell membrane formation and neurotransmitter synthesis, and its abnormal metabolism is associated with the onset of AD. With the continuous advancement of imaging techniques and molecular biology methods, researchers can more accurately explore the relationship between cholesterol metabolism and AD. Elevated cholesterol levels may lead to vascular dysfunction, thereby affecting neuronal function. Additionally, abnormal cholesterol metabolism may affect the metabolism of β-amyloid protein, thereby promoting the onset of AD. Brain cholesterol levels are regulated by multiple factors. This review aims to deepen the understanding of the subtle relationship between cholesterol homeostasis and AD, and to introduce the latest advances in cholesterol-regulating AD treatment strategies, thereby inspiring readers to contemplate deeply on this complex relationship. Although there are still many unresolved important issues regarding the risk of brain cholesterol and AD, and some studies may have opposite conclusions, further research is needed to enrich our understanding. However, these findings are expected to deepen our understanding of the pathogenesis of AD and provide important insights for the future development of AD treatment strategies targeting brain cholesterol homeostasis.

Design and Rationale of a Two-Armed Randomized Controlled Trial on Yoga/Brisk Walking-Based Lifestyle Modification on Dementia Risk Reduction, and Influence of ApoE Genotypes on the Intervention

Background/Introduction

Though considered a late-onset disease, the 2020 report of the Lancet Commission emphasizes the necessity of conducting primary prevention trials with an approach of never too early in the life course for dementia prevention. Driven by the same notion, we hereby aim to compare the dementia risk reduction potential of two potential interventions, 48 weeks (12 months) of yoga and brisk walking, in middle-aged high-risk subjects.

Design

A randomized controlled trial.

Setting

Community in India.

Participants

In total, 323 at-risk dementia subjects will be recruited from community settings through health awareness camps and door-to-door surveys across Delhi, India. Participants will be randomized into yoga or brisk-walking groups (1:1). The yoga intervention group will receive 60 contact yoga sessions per 60-min/day at the community parks, followed by continued tele-supervised home practice, further followed by at-home self-practice, and will be tested at 3-time points (baseline, 24-week and 48-week, post-randomization) to test the efficacy of the intervention. The control group will be asked to do brisk walking daily for 45 minutes at their convenience, followed by weekly telephone follow-ups. Applying the intention-to-treat principle, the primary endpoint will be the change from baseline at the 12th month in the Cardiovascular Risk Factors, Aging, and Dementia (CAIDE) Scores. Secondary outcomes will include the composite scores derived from a comprehensive neuropsychology battery, comprising the Trail Making Test, Digit Span Test, N Back, Color Trail, Animal Fluency Test, COWA (Controlled Oral Word Association Test), and Digit Symbol Substitution. The primary outcome will be analyzed using mixed-effect models for repeated measures, adjusted for covariates as fixed effects. The study has been prospectively registered (CTRI/2023/02/049746) on February 15, 2023. The protocol was conceptualized in 2021 and approved by the Institutional Ethics Committee of SVYASA. Recruitment began in February 2023 and is underway with patient enrollment.

Conclusion

To our knowledge, this is the first controlled trial to investigate the longitudinal effects of a yoga-based intervention on dementia risk reduction using the CAIDE risk score. The findings of this trial will also provide insight into a better understanding of genotype-dependent responses to yoga intervention and open up avenues for understanding the implications of gene-intervention interactions for precision prevention using yoga.

Effects of Exercise Training and L-Arginine Loaded Chitosan Nanoparticles on Hippocampus Histopathology, β-Secretase Enzyme Function, APP, Tau, Iba1and APOE-4 mRNA in Aging Rats

The objective of this study was to evaluate the combined and independent effects of exercise training and L-Arginine loaded chitosan nanoparticles (LA CNPs) supplementation on hippocampal Tau, App, Iba1, and ApoE gene expression, oxidative stress, β-secretase enzyme activity, and hippocampus histopathology in aging rats. Thirty-five male Wistar rats were randomly assigned to five groups (n = 7 in each): Young (8 weeks old), Old (20 months old), old + L-arginine supplementation (Old Sup), old + exercise (Old Exe) and old + L-arginine supplementation + exercise (Old Sup + Exe). LA CNPs were administered to the supplement groups through gavage at a dosage of 500 mg/kg/day for 6-weeks. Exercise groups were subjected to a swimming exercise program five days/week for the same duration. Upon the completion of their interventions, the animals underwent behavioral and open-field task tests and were subsequently sacrificed for hippocampus genetic and histopathological evaluation. For histopathological analysis of brain, Cresyl violet staining was used. Congo Red staining was employed to confirm amyloid plaques in the hippocampus. Expressions of Tau, App, Iba1, and ApoE genes were determined by real-time PCR. In contrast to the Old group, Old Exe and Old Sup + Exe groups spent more time in the central space in the open field task (p < 0.05) and have more live cells in the hippocampus. Old rats (Old, Old Sup and Old Exe groups) exhibited a significant Aβ peptide accumulation and increases in APP, Tau, Iba1, APOE-4 mRNA and MDA, along with decreases in SOD compared to the young group (p < 0.05). However, LA CNPs supplementation, exercise, and their combination (Old Sup, Old Exe and Old Sup + Exe) significantly reduced MDA, Aβ plaque as well as APP, Tau, Iba1, and APOE-4 mRNA compared to the Old group (p < 0.05). Consequently, the administration of LA CNPs supplements and exercise might regulate the risk factors of hippocampus cell and tissue.

Brain metabolism in Alzheimer's disease: biological mechanisms of exercise

Alzheimer's disease (AD) is a major subtype of neurodegenerative dementia caused by long-term interactions and accumulation of multiple adverse factors, accompanied by dysregulation of numerous intracellular signaling and molecular pathways in the brain. At the cellular and molecular levels, the neuronal cellular milieu of the AD brain exhibits metabolic abnormalities, compromised bioenergetics, impaired lipid metabolism, and reduced overall metabolic capacity, which lead to abnormal neural network activity and impaired neuroplasticity, thus accelerating the formation of extracellular senile plaques and intracellular neurofibrillary tangles. The current absence of effective pharmacological therapies for AD points to the urgent need to investigate the benefits of non-pharmacological approaches such as physical exercise. Despite the evidence that regular physical activity can improve metabolic dysfunction in the AD state, inhibit different pathophysiological molecular pathways associated with AD, influence the pathological process of AD, and exert a protective effect, there is no clear consensus on the specific biological and molecular mechanisms underlying the advantages of physical exercise. Here, we review how physical exercise improves crucial molecular pathways and biological processes associated with metabolic disorders in AD, including glucose metabolism, lipid metabolism, Aβ metabolism and transport, iron metabolism and tau pathology. How metabolic states influence brain health is also presented. A better knowledge on the neurophysiological mechanisms by which exercise improves AD metabolism can contribute to the development of novel drugs and improvement of non-pharmacological interventions.

Examining later-in-life health risks associated with sport-related concussion and repetitive head impacts: a systematic review of case-control and cohort studies

OBJECTIVE

Concern exists about possible problems with later-in-life brain health, such as cognitive impairment, mental health problems and neurological diseases, in former athletes. We examined the future risk for adverse health effects associated with sport-related concussion, or exposure to repetitive head impacts, in former athletes.

DESIGN

Systematic review.

DATA SOURCES

Search of MEDLINE, Embase, Cochrane, CINAHL Plus and SPORTDiscus in October 2019 and updated in March 2022.

ELIGIBILITY CRITERIA

Studies measuring future risk (cohort studies) or approximating that risk (case-control studies).

RESULTS

Ten studies of former amateur athletes and 18 studies of former professional athletes were included. No postmortem neuropathology studies or neuroimaging studies met criteria for inclusion. Depression was examined in five studies in former amateur athletes, none identifying an increased risk. Nine studies examined suicidality or suicide as a manner of death, and none found an association with increased risk. Some studies comparing professional athletes with the general population reported associations between sports participation and dementia or amyotrophic lateral sclerosis (ALS) as a cause of death. Most did not control for potential confounding factors (eg, genetic, demographic, health-related or environmental), were ecological in design and had high risk of bias.

CONCLUSION

Evidence does not support an increased risk of mental health or neurological diseases in former amateur athletes with exposure to repetitive head impacts. Some studies in former professional athletes suggest an increased risk of neurological disorders such as ALS and dementia; these findings need to be confirmed in higher quality studies with better control of confounding factors.

PROSPERO REGISTRATION NUMBER

CRD42022159486.

Consensus statement on concussion in sport: the 6th International Conference on Concussion in Sport-Amsterdam, October 2022

For over two decades, the Concussion in Sport Group has held meetings and developed five international statements on concussion in sport. This 6th statement summarises the processes and outcomes of the 6th International Conference on Concussion in Sport held in Amsterdam on 27-30 October 2022 and should be read in conjunction with the (1) methodology paper that outlines the consensus process in detail and (2) 10 systematic reviews that informed the conference outcomes. Over 3½ years, author groups conducted systematic reviews of predetermined priority topics relevant to concussion in sport. The format of the conference, expert panel meetings and workshops to revise or develop new clinical assessment tools, as described in the methodology paper, evolved from previous consensus meetings with several new components. Apart from this consensus statement, the conference process yielded revised tools including the Concussion Recognition Tool-6 (CRT6) and Sport Concussion Assessment Tool-6 (SCAT6, Child SCAT6), as well as a new tool, the Sport Concussion Office Assessment Tool-6 (SCOAT6, Child SCOAT6). This consensus process also integrated new features including a focus on the para athlete, the athlete's perspective, concussion-specific medical ethics and matters related to both athlete retirement and the potential long-term effects of SRC, including neurodegenerative disease. This statement summarises evidence-informed principles of concussion prevention, assessment and management, and emphasises those areas requiring more research.

How does apolipoprotein E genotype influence the relationship between physical activity and Alzheimer's disease risk? A novel integrative model

BACKGROUND

Wide evidence suggests that physical activity (PA) confers protection against Alzheimer's disease (AD). On the other hand, the apolipoprotein E gene (APOE) ε4 allele represents the greatest genetic risk factor for developing AD. Extensive research has been conducted to determine whether frequent PA can mitigate the increased AD risk associated with APOE ε4. However, thus far, these attempts have produced inconclusive results. In this context, one possible explanation could be that the influence of the combined effect of PA and APOE ε4 carriage might be dependent on the specific outcome measure utilised.

MAIN BODY

In order to bridge these discrepancies, the aim of this theoretical article is to propose a novel model on the interactive effects of PA and APOE ε4 carriage on well-established mechanisms underlying AD. Available literature was searched to investigate how PA and APOE ε4 carriage, independently and in combination, may alter several molecular pathways involved in AD pathogenesis. The reviewed mechanisms include amyloid beta (Aβ) and tau deposition and clearance, neuronal resilience and neurogenesis, lipid function and cerebrovascular alterations, brain immune response and glucose metabolism. Finally, combining all this information, we have built an integrative model, which includes evidence-based and theoretical synergistic interactions across mechanisms. Moreover, we have identified key knowledge gaps in the literature, providing a list of testable hypotheses that future studies need to address.

CONCLUSIONS

We conclude that PA influences a wide array of molecular targets involved in AD neuropathology. A deeper understanding of where, when and, most importantly, how PA decreases AD risk even in the presence of the APOE ε4 allele will enable the creation of new protocols using exercise along pharmaceuticals in combined therapeutic approaches.

Association between driving a car and retention of brain volume in Japanese older adults

BACKGROUND

Driving cessation is a major negative life event that has been associated with a decline in health conditions including dementia. The increase in activity owing to the expansion of life space is a possible explanation for the positive relationship between driving and brain health. The present study examined the association between driving, life space, and structural brain volume in older individuals.

METHODS

High-resolution magnetic resonance imaging was employed to examine the brain volume in 1063 older adults. Participants were classified as non-drivers, those who drove <7 days a week, and everyday drivers. They were further classified into a non-driving group, an active group (drove 10 km at least once a week), and a less-active group (drove 10 km less than once a week).

RESULTS

The hippocampal volume was greater in drivers than in non-drivers. Occipital cortex volume was greater in low-frequency drivers than in non-drivers and high-frequency drivers. Active drivers exhibited larger temporal cortex volumes than less-active drivers, larger cingulate cortex volumes than non-drivers and less-active drivers, and larger hippocampal volumes than non-drivers.

CONCLUSION

Driving was associated with hippocampal brain atrophy attenuation, with active drivers exhibiting decreased brain atrophy in the temporal and cingulate cortices.

ApoE in Alzheimer’s disease: pathophysiology and therapeutic strategies

Alzheimer’s disease (AD) is the most common cause of dementia worldwide, and its prevalence is rapidly increasing due to extended lifespans. Among the increasing number of genetic risk factors identified, the apolipoprotein E (APOE) gene remains the strongest and most prevalent, impacting more than half of all AD cases. While the ε4 allele of the APOE gene significantly increases AD risk, the ε2 allele is protective relative to the common ε3 allele. These gene alleles encode three apoE protein isoforms that differ at two amino acid positions. The primary physiological function of apoE is to mediate lipid transport in the brain and periphery; however, additional functions of apoE in diverse biological functions have been recognized. Pathogenically, apoE seeds amyloid-β (Aβ) plaques in the brain with apoE4 driving earlier and more abundant amyloids. ApoE isoforms also have differential effects on multiple Aβ-related or Aβ-independent pathways. The complexity of apoE biology and pathobiology presents challenges to designing effective apoE-targeted therapeutic strategies. This review examines the key pathobiological pathways of apoE and related targeting strategies with a specific focus on the latest technological advances and tools.

Dementia Prevention in Clinical Practice

Over 55 million people globally are living with dementia and, by 2050, this number is projected to increase to 131 million. This poses immeasurable challenges for patients and their families and a significant threat to domestic and global economies. Given this public health crisis and disappointing results from disease-modifying trials, there has been a recent shift in focus toward primary and secondary prevention strategies. Approximately 40% of Alzheimer's disease (AD) cases, which is the most common form of dementia, may be prevented or at least delayed. Success of risk reduction studies through addressing modifiable risk factors, in addition to the failure of most drug trials, lends support for personalized multidomain interventions rather than a "one-size-fits-all" approach. Evolving evidence supports early intervention in at-risk patients using individualized interventions directed at modifiable risk factors. Comprehensive risk stratification can be informed by emerging principals of precision medicine, and include expanded clinical and family history, anthropometric measurements, blood biomarkers, neurocognitive evaluation, and genetic information. Risk stratification is key in differentiating subtypes of dementia and identifies targetable areas for intervention. This article reviews a clinical approach toward dementia risk stratification and evidence-based prevention strategies, with a primary focus on AD.

APOE in the bullseye of neurodegenerative diseases: impact of the APOE genotype in Alzheimer's disease pathology and brain diseases

ApoE is the major lipid and cholesterol carrier in the CNS. There are three major human polymorphisms, apoE2, apoE3, and apoE4, and the genetic expression of APOE4 is one of the most influential risk factors for the development of late-onset Alzheimer's disease (AD). Neuroinflammation has become the third hallmark of AD, together with Amyloid-β plaques and neurofibrillary tangles of hyperphosphorylated aggregated tau protein. This review aims to broadly and extensively describe the differential aspects concerning apoE. Starting from the evolution of apoE to how APOE's single-nucleotide polymorphisms affect its structure, function, and involvement during health and disease. This review reflects on how APOE's polymorphisms impact critical aspects of AD pathology, such as the neuroinflammatory response, particularly the effect of APOE on astrocytic and microglial function and microglial dynamics, synaptic function, amyloid-β load, tau pathology, autophagy, and cell-cell communication. We discuss influential factors affecting AD pathology combined with the APOE genotype, such as sex, age, diet, physical exercise, current therapies and clinical trials in the AD field. The impact of the APOE genotype in other neurodegenerative diseases characterized by overt inflammation, e.g., alpha- synucleinopathies and Parkinson's disease, traumatic brain injury, stroke, amyotrophic lateral sclerosis, and multiple sclerosis, is also addressed. Therefore, this review gathers the most relevant findings related to the APOE genotype up to date and its implications on AD and CNS pathologies to provide a deeper understanding of the knowledge in the APOE field.

A healthy mind in a healthy body: Effects of arteriosclerosis and other risk factors on cognitive aging and dementia

In this review we start from the assumption that, to fully understand cognitive aging, it is important to embrace a holistic view, integrating changes in bodily, brain, and cognitive functions. This broad view can help explain individual differences in aging trajectories and could ultimately enable prevention and remediation strategies. As the title of this review suggests, we claim that there are not only indirect but also direct effects of various organ systems on the brain, creating cascades of phenomena that strongly contribute to age-related cognitive decline. Here we focus primarily on the cerebrovascular system, because of its direct effects on brain health and close connections with the development and progression of Alzheimer's Disease and other types of dementia. We start by reviewing the main cognitive changes that are often observed in normally aging older adults, as well as the brain systems that support them. Second, we provide a brief overview of the cerebrovascular system and its known effects on brain anatomy and function, with a focus on aging. Third, we review genetic and lifestyle risk factors that may affect the cerebrovascular system and ultimately contribute to cognitive decline. Lastly, we discuss this evidence, review limitations, and point out avenues for additional research and clinical intervention.

APOE ε4 and exercise interact in a sex-specific manner to modulate dementia risk factors

Introduction

Apolipoprotein E (APOE) ε4 is the strongest genetic risk factor for Alzheimer's disease and related dementias (ADRDs), affecting many different pathways that lead to cognitive decline. Exercise is one of the most widely proposed prevention and intervention strategies to mitigate risk and symptomology of ADRDs. Importantly, exercise and APOE ε4 affect similar processes in the body and brain. While both APOE ε4 and exercise have been studied extensively, their interactive effects are not well understood.

Methods

To address this, male and female APOE ε3/ε3, APOE ε3/ε4, and APOE ε4/ε4 mice ran voluntarily from wean (1 month) to midlife (12 months). Longitudinal and cross-sectional phenotyping were performed on the periphery and the brain, assessing markers of risk for dementia such as weight, body composition, circulating cholesterol composition, murine daily activities, energy expenditure, and cortical and hippocampal transcriptional profiling.

Results

Data revealed chronic running decreased age-dependent weight gain, lean and fat mass, and serum low-density lipoprotein concentration dependent on APOE genotype. Additionally, murine daily activities and energy expenditure were significantly influenced by an interaction between APOE genotype and running in both sexes. Transcriptional profiling of the cortex and hippocampus predicted that APOE genotype and running interact to affect numerous biological processes including vascular integrity, synaptic/neuronal health, cell motility, and mitochondrial metabolism, in a sex-specific manner.

Discussion

These data in humanized mouse models provide compelling evidence that APOE genotype should be considered for population-based strategies that incorporate exercise to prevent ADRDs and other APOE-relevant diseases.