The Benefits of Exercise and Metabolic Interventions for the Prevention and Early Treatment of Alzheimer's Disease

Exercise-Induced Reduction of IGF1R Sumoylation Attenuates Neuroinflammation in APP/PS1 Transgenic Mice

INTRODUCTION

Alzheimer's Disease (AD), a progressive neurodegenerative disorder, is marked by cognitive deterioration and heightened neuroinflammation. The influence of Insulin-like Growth Factor 1 Receptor (IGF1R) and its post-translational modifications, especially sumoylation, is crucial in understanding the progression of AD and exploring novel therapeutic avenues.

OBJECTIVES

This study investigates the impact of exercise on the sumoylation of IGF1R and its role in ameliorating AD symptoms in APP/PS1 mice, with a specific focus on neuroinflammation and innovative therapeutic strategies.

METHODS

APP/PS1 mice were subjected to a regimen of moderate-intensity exercise. The investigation encompassed assessments of cognitive functions, alterations in hippocampal protein expressions, neuroinflammatory markers, and the effects of exercise on IGF1R and SUMO1 nuclear translocation. Additionally, the study evaluated the efficacy of KPT-330, a nuclear export inhibitor, as an alternative to exercise.

RESULTS

Exercise notably enhanced cognitive functions in AD mice, possibly through modulations in hippocampal proteins, including Bcl-2 and BACE1. A decrease in neuroinflammatory markers such as IL-1β, IL-6, and TNF-α was observed, indicative of reduced neuroinflammation. Exercise modulated the nuclear translocation of SUMO1 and IGF1R in the hippocampus, thereby facilitating neuronal regeneration. Mutant IGF1R (MT IGF1R), lacking SUMO1 modification sites, showed reduced SUMOylation, leading to diminished expression of pro-inflammatory cytokines and apoptosis. KPT-330 impeded the formation of the IGF1R/RanBP2/SUMO1 complex, thereby limiting IGF1R nuclear translocation, inflammation, and neuronal apoptosis, while enhancing cognitive functions and neuron proliferation.

CONCLUSION

Moderate-intensity exercise effectively mitigates AD symptoms in mice, primarily by diminishing neuroinflammation, through the reduction of IGF1R Sumoylation. KPT-330, as a potential alternative to physical exercise, enhances the neuroprotective role of IGF1R by inhibiting SUMOylation through targeting XPO1, presenting a promising therapeutic strategy for AD.

Leisure-time physical activity mitigated the cognitive effect of PM2.5 and PM2.5 components exposure: Evidence from a nationwide longitudinal study

BACKGROUND

Exposure to fine particulate matter (PM2.5) impairs cognition, while physical activity (PA) improves cognitive function. However, whether taking PA with PM2.5 exposure is still beneficial to cognition remains unknown.

METHODS

We utilized national representative longitudinal data from the China Family Panel Study (CFPS), comprising a total sample of 108,099 from 2010 to 2018 in three waves. Cognitive performance and leisure-time PA were measured using the standard cognitive module and Godin-Shephard Leisure-Time Physical Activity Questionnaire. Gridded overall PM2.5 and major chemical components of PM2.5 were estimated using a two-stage machine learning model and matched to each participant based on their residential location. Mixed-effect models and difference-in-difference models were employed to investigate the individual and joint effects of total PM2.5, PM2.5 components, and leisure-time PA on cognition.

RESULTS

Every 1 μg/m3 increase in PM2.5 was associated with a -0.035 (95% confidence interval [CI] = -0.052, -0.018) point change in cognitive score. All PM2.5 components exhibited negative associations with cognitive change, with black carbon (BC) contributing the most significant cognitive decline (β = -1.025, 95% CI = -1.367, -0.683). Every one-time (or one-hour) increase in leisure-time PA frequency (or PA time) per week was associated with an increase in cognitive score by 0.576 (0.270) points (PA frequency: 95% CI = 0.544, 0.608, PA time: 95% CI = 0.248, 0.293). PA frequency (β = -0.005, 95% CI = -0.006, -0.003) and PA time (β = -0.002, 95% CI = -0.003, -0.001) exhibited interactive effects with PM2.5. Increased PA frequency and time were more beneficial to cognitive function in the low PM2.5 exposure group compared to those exposed to high PM2.5 levels. Moreover, relative to lower PM2.5 exposure, the cognitive benefits of physically active individuals with higher PM2.5 exposure were attenuated but still improved cognition when compared to those with no PA.

CONCLUSION

Engaging in leisure-time PA provides cognitive benefits even under PM2.5 exposure, although PM2.5 exposure attenuates these benefits. Among all PM2.5 components, BC demonstrated the most significant cognitive hazard and interaction with leisure-time PA. Promoting PA as a preventive measure may offer a cost-effective and convenient strategy to mitigate the negative impact of PM2.5 exposure on cognition. There is no excuse to avoid PA under PM2.5 exposure, as its cognitive benefits persist even in polluted environments.

Exercise Protects Against Cognitive Injury and Inflammation in Alzheimer's Disease Through Elevating miR-148a-3p

Alzheimer's disease (AD) is a chronic neurological disorder with high morbidity. Exercise is one of the effective ways to ameliorate AD. In this study, we assessed the effects of exercise on cognition and inflammation and studied the role of miR-148a-3p in AD. In 88 patients with AD, the expression of miR-148a-3p was studied using qRT-PCR. ROC curve and Pearson analysis were utilized to evaluate the roles of miR-148a-3p in AD. MWM test was conducted to investigate the effects of miR-148a-3p and exercise on cognition and memory. Moreover, inflammatory indicators were identified using an enzyme-linked immunosorbent assay. Relative luciferase levels reflected whether miR-148a-3p targeted SYNJ1. miR-148a-3p levels declined in patients with AD, indicating its potential as a biomarker. Interestingly, miR-148a-3p levels were elevated in patients with AD after exercise. MiR-148a-3p levels correlated with cognitive scores and proinflammatory levels. The cognitive situation and pro-inflammatory state were partly recovered in the mice after exercise. MiR-148a-3p silencing reversed these abovementioned tendencies. Patients with AD exhibited a low level of miR-148a-3p, which was increased after exercise. Therefore, exercise might improve the cognitive function and memory of mice with AD by upregulating miR-148a-3p.

Effects of traditional Chinese exercise on vascular function in patients with Alzheimer's disease: A protocol for systematic review and network meta-analysis of randomized controlled trials

BACKGROUND

Alzheimer's disease (AD) is a progressive neurodegenerative disorder with an insidious onset, usually characterized by memory impairment, visual-spatial skill impairment, executive dysfunction and personality behavioral changes. Studies have confirmed that vascular dysfunction may precede AD pathological changes and can present as vascular malformations, atherosclerosis, and impaired self-regulation, and can affect oxidative stress and amyloidosis. Therefore, it is important to improve or prevent vascular dysfunction in AD patients. Regular exercise can effectively inhibit the production of reactive oxygen species during the occurrence of AD and can improve the reduction of cerebral blood flow due to AD. Previous studies have shown that exercise can achieve superior clinical results in improving vascular function in AD patients. Therefore, we hypothesize that traditional Chinese exercises (TCEs) may have a good clinical effect in improving vascular function in patients with AD.

METHODS

We will search "PubMed," "the Cochrane Library," "Embase," "Web of Science," "CINAHL," "ProQuest Dissertations and Theses," and "ProQuest-Health & Medical Collection," "CNKI," "SinoMed," "VIP," and "Wanfang Data" to find randomized controlled trials of the effects of TCEs on AD vascular function from the creation of the database to the present, including at least 1 indicator in carotid intima-media thickness (cIMT), middle cerebral artery mean flow velocity (MFV), blood indicators [Heme Oxidase-1 (HO-1), angiopoietin I (Ang I), vascular endothelial growth factor (VEGF), brain-derived neurotrophic factor, matrix metalloproteinase-9 (MMP-9)], and arterial stiffness [(Ankle Brachial Index (ABI), pulse wave velocity (PWV)]. For the included literature, Excel 2019 will be used for data extraction and collection. For the indicators that can be netted for network meta-analysis, Surface Under the Cumulative Ranking for each exercise modality will be calculated with the help of Stata 16.0 and rank, where the higher the SUCRA score, the higher the ranking. For the indicators that cannot be netted, Review Manager 5.4 will be used for meta-analysis will be performed to evaluate the improvement effect of TCEs on AD patients.

RESULTS

This meta-analysis will further determine the efficacy and safety of TCEs on vascular function in AD patients.

CONCLUSION

In this study, randomized controlled trials of the effects of TCEs on vascular function in AD patients will be selected to provide evidence-based medical evidence for promoting the application of TCEs by observing the order of advantages and disadvantages of various exercise modalities through network meta-analysis.

Insulin resistance in Alzheimer's disease: The genetics and metabolomics links

Alzheimer's disease (AD) is a neurodegenerative disease with significant socioeconomic burden worldwide. Although genetics and environmental factors play a role, AD is highly associated with insulin resistance (IR) disorders such as metabolic syndrome (MS), obesity, and type two diabetes mellitus (T2DM). These findings highlight a shared pathogenesis. The use of metabolomics as a downstream systems' biology (omics) approach can help to identify these shared metabolic traits and assist in the early identification of at-risk groups and potentially guide therapy. Targeting the shared AD-IR metabolic trait with lifestyle interventions and pharmacological treatments may offer promising AD therapeutic approach. In this narrative review, we reviewed the literature on the AD-IR pathogenic link, the shared genetics and metabolomics biomarkers between AD and IR disorders, as well as the lifestyle interventions and pharmacological treatments which target this pathogenic link.

The BET inhibitor apabetalone decreases neuroendothelial proinflammatory activation in vitro and in a mouse model of systemic inflammation

Brain vascular inflammation is characterized by endothelial activation and immune cell recruitment to the blood vessel wall, potentially causing a breach in the blood - brain barrier, brain parenchyma inflammation, and a decline of cognitive function. The clinical-stage small molecule, apabetalone, reduces circulating vascular endothelial inflammation markers and improves cognitive scores in elderly patients by targeting epigenetic regulators of gene transcription, bromodomain and extraterminal proteins. However, the effect of apabetalone on cytokine-activated brain vascular endothelial cells (BMVECs) is unknown. Here, we show that apabetalone treatment of BMVECs reduces hallmarks of in vitro endothelial activation, including monocyte chemoattractant protein-1 (MCP-1) and RANTES chemokine secretion, cell surface expression of endothelial cell adhesion molecule VCAM-1, as well as endothelial capture of THP-1 monocytes in static and shear stress conditions. Apabetalone pretreatment of THP-1 downregulates cell surface expression of chemokine receptors CCR1, CCR2, and CCR5, and of the VCAM-1 cognate receptor, integrin α4. Consequently, apabetalone reduces THP-1 chemoattraction towards soluble CCR ligands MCP-1 and RANTES, and THP-1 adhesion to activated BMVECs. In a mouse model of brain inflammation, apabetalone counters lipopolysaccharide-induced transcription of endothelial and myeloid cell markers, consistent with decreased neuroendothelial inflammation. In conclusion, apabetalone decreases proinflammatory activation of brain endothelial cells and monocytes in vitro and in the mouse brain during systemic inflammation.

Effects of physical activity on visuospatial working memory in healthy individuals: A systematic review and meta-analysis

Introduction

Physical activity interventions improve cognitive performance, especially visuospatial working memory (VSWM). However, evidence on the effects of these interventions in children, adolescents, and older adults remains scant. This meta-analysis aimed to identify the effects of physical activity on VSWM improvement in healthy individuals and the best exercise intervention program to improve VSWM capacity.

Methods

We searched for randomized controlled trials (RCTs) of exercise interventions targeting VSWM in healthy individuals from Web of Science, MEDLINE, BIOSIS Previews, PubMed, China National Knowledge Infrastructure, and Wanfang Data (Chinese) databases, from inception to August 20, 2022.

Results

Among 21 articles (1,595 healthy participants), the heterogeneity test statistic was I2 = 32.3%, p = 0.053. The mean quality scores of the included articles were 6.9 points (reaction time [RT] studies) and 7.5 points (Score studies). Moreover, 28 RCTs were included (10 RT studies and 18 Score studies), and the subgroup analysis found significant effects for elderly participants, children, interventions involving a higher level of cognitive engagement, low and moderate exercise intensity, chronic exercise, exercise duration ≥60 min, and exercise period ≥90 days. Physical activity had a small but significant positive impact on VSWM in healthy individuals. Current evidence confirms the effects of physical activity on VSWM capacity only in children and seniors but not in young adults. Other age groups, including adolescents and middle-aged adults, have not been studied. Prescription of interventions involving high-level cognitive engagement, low and moderate exercise intensity, chronic exercise, exercise for >30 min per session, and exercise for more than 3 months is recommended for children and seniors.

Discussion

Future RCTs would be to fill the gap in studies on adolescents and middle-aged adults, and report detailed exercise intervention programs about different age groups.Systematic Review Registration: PROSPERO (https://www.crd.york.ac.uk/prospero/display_record.php?ID=CRD42022354737). INPLASY (https://doi.org/10.37766/inplasy2022.8.0053).

Meta analysis of aerobic exercise improving intelligence and cognitive function in patients with Alzheimer's disease

OBJECTIVE

Alzheimer's disease (AD) is a neurodegenerative disease. This study aims to explore the intervention and treatment effects of aerobic exercise and different exercise modes on AD through meta-analysis.

METHODS

Using the set inclusion and exclusion criteria, retrieve the China national knowledge infrastructure (CNKI), Wanfang Data Knowledge Service Platform, China Science and Technology Journal Database, Cochrane Library, and PubMed were searched from January 1, 2012, to December 31, 2021. Cochrane risk bias assessment tool was used to evaluate the quality of the included articles, and ReMan5.4.1 was used for forest plot analysis of mini-mental state exam (MMSE) score indicators included in the included articles.

RESULTS

Twelve randomized controlled trials and 795 samples were included. Meta analysis of all articles: I2 = 91%, P ≤ .00001, (MD = 2.95, 95%CI [2.49, 3.40], P ≤ .00001). Meta analysis of 5 fit aerobics groups: I2 = 4%, P = .38, (MD = 1.53, 95%CI [0.72, 2.33], P = .0002); meta-analysis of three spinning groups: I2 = 3%, P = .36, (MD = 1.79, 95%CI [0.29, 3.29], P = .02).

CONCLUSION

Aerobic exercise can effectively improve intellectual and cognitive impairment in AD patients, and for different forms of aerobic exercise, the therapeutic effect of spinning aerobic exercise is better than that of fit aerobics.

High frequency repetitive transcranial magnetic stimulation improves cognitive performance parameters in patients with Alzheimer's disease - an exploratory pilot study

BACKGROUND

Currently available medication for Alzheimer's disease (AD) may slows cognitive decline only transitory, but has failed to bring about long term positive effects. For this slowly progressive neurodegenerative disease so far no disease modifying therapy exists.

OBJECTIVE

To find out if non-pharmacologic non-ivasive neuromodulatory repetitive transcranial magnetic stimulation (rTMS) may offer a new alternative or an add on therapeutic strategy against loss of cognitive functions.

METHODS

In this exploratory intervention study safety and symptom development before and after frontopolar cortex stimulation (FPC) using intermittent theta burst stimulation (iTBS) at 10 subsequent working days was monitored as add-on treatment in 28 consecutive patients with AD. Out of these, 10 randomly selected patients received sham stimulation as a control. In addition, ​serum concentrations of neurotransmitter precursor amino acids, of immune activation and inflammation markers, of brain derived neurotrophic factor (BDNF) as well as of nitrite were measured.

RESULTS

Treatment was well tolerated, no serious adverse effects were observed. Improvement of cognition was detected by an increase of Mini Mental State Examination score (MMSE; p<0.01, paired rank test) and also by an increase in a modified repeat address phrase test, part of the 6-item cognitive ​impairment test (p < 0.01). A trend to an increase in the clock drawing test (CDT; p = 0.08) was also found in the verum treated group. Furtheron, in 10 of the AD patients with additional symptoms of depression treated with iTBS, a significant decrease in the HAMD-7 scale (p <0.01) and a trend to lower serum phenylalanine concentrations (p = 0.08) was seen. No changes of the parameters tested were found in the sham treated patients.

CONCLUSION

Our preliminary results may indicate that iTBS is effective in the treatment of AD. Also a slight influence of iTBS on the metabolism of phenylalanine was found after 10 iTBS sessions. An impact of iTBS to influence the enzyme phenylalanine hydroxylase (PAH), as found in previous series of treatment resistant depression, could not be seen in this our first observational trial in 10 AD patients with comorbidity of depression. Longer treatment periods for several weeks in a higher number of AD patients with depression could cause more intense and disease modifying effects visible in different neurotransmitter concentrations important in the pathogenesis of AD.

Swimming exercise prevents hippocampal dendritic spine changes and memory loss caused by aging: An application of a new semi-automated spine analysis software

Dendritic spines are small, ratchet-like protrusions on neuronal dendrites that form synapses for receiving neuronal messages. Dendritic spine morphology is associated with synapse function. If neurons degrade or are damaged, the spine morphology of neurons changes. Given that most commercially available spine analysis software is expensive and complex, this study investigated a semi-automated spine analysis software, CTSpine, and used previously published data to verify the accuracy of the analysis results of this software. We also applied CTSpine to understand whether aging causes alterations in the hippocampal spine morphology and whether physical exercise can impede dendritic spine changes in 20 male Sprague Dawley rats. The spines of pyramidal cells in the hippocampal Cornu Ammonis 1 (CA1) region in the aging group were more enriched in filopodium type pattern than those in the control group, whereas the spines of the exercised aging group showed a similar pattern to that of the control. No significant changes were observed in neuronal dendritic spines in other hippocampal regions. However, long-term hippocampal memory was considerably decreased in the aging group, which was reversed to some extent in the exercised aging group. CTSpine, a self-developed semi-automatic spine analysis software, showed results similar to those noted in published data and can be effectively applied to the study of dendritic patterns, including neurodevelopment and disease.

Effects of involuntary treadmill running in combination with swimming on adult neurogenesis in an Alzheimer's mouse model

Physical exercise plays a role on the prevention and treatment of Alzheimer's disease (AD), but the exercise mode and the mechanism for these positive effects is still ambiguous. Here, we investigated the effect of an aerobic interval exercise, running in combination with swimming, on behavioral dysfunction and associated adult neurogenesis in a mouse model of AD. We demonstrate that 4 weeks of the exercise could ameliorate Aβ₄₂ oligomer-induced cognitive impairment in mice utilizing Morris water maze tests. Additionally, the exercised Aβ₄₂ oligomer-induced mice exhibited a significant reduction of anxiety- and depression-like behaviors compared to the sedentary Aβ₄₂ oligomer-induced mice utilizing an Elevated zero maze and a Tail suspension test. Moreover, by utilizing 5'-bromodeoxyuridine (BrdU) as an exogenous cell tracer, we found that the exercised Aβ₄₂ oligomer-induced mice displayed a significant increase in newborn cells (BrdU⁺ cells), which differentiated into a majority of neurons (BrdU⁺ DCX⁺ cells or BrdU⁺NeuN⁺ cells) and a few of astrocytes (BrdU⁺GFAP⁺ cells). Likewise, the exercised Aβ₄₂ oligomer-induced mice also displayed the higher levels of NeuN, PSD95, synaptophysin, Bcl-2 and lower level of GFAP protein. Furthermore, alteration of serum metabolites in transgenic AD mice between the exercised and sedentary group were significantly associated with lipid metabolism, amino acid metabolism, and neurotransmitters. These findings suggest that combined aerobic interval exercise-mediated metabolites and proteins contributed to improving adult neurogenesis and behavioral performance after AD pathology, which might provide a promising therapeutic strategy for AD.

Blind sports’ blind spot: The global epidemiology of visual impairment against participation trends in elite blind para sport

Background: It remains unknown whether access to elite blind sports opportunities is globally balanced or matches the prevalence of blindness/visual impairment (VI). The primary objective of this study was to determine the rate of elite blind sports participation in each world region registered in the International Blind Sports Federation’s (IBSA) and to assess its association with the global and regional prevalence of blindness/VI. The secondary objective was to determine the association between other covariates, such as age, vision class, and sex, with the number of IBSA-registered athletes from each region.

Methods: A baseline estimate of blindness/VI data was established and used when comparing participation rates to blindness/VI rates. Descriptive statistics were used to describe sports participation and associated co-variates.

Results: Among 123 member countries registered in IBSA, 31 did not have any completed registrations in blind sports, of which 22 had a prevalence of blindness/VI higher than the global average. During the summer season 2019, 738 (29.52%) IBSA athletes were female and 1762 (70.48%) were male.

Conclusions: These results suggest elite blind/VI sport participation is limited independently from blindness/VI prevalence. Increasing blind-friendly sport resources, especially in low-and-middle-income countries (LMICs), would improve the rate of elite sport participation among athletes with blindness/VI.

Disentangling Mitochondria in Alzheimer's Disease

Alzheimer's disease (AD) is a major cause of dementia in older adults and is fast becoming a major societal and economic burden due to an increase in life expectancy. Age seems to be the major factor driving AD, and currently, only symptomatic treatments are available. AD has a complex etiology, although mitochondrial dysfunction, oxidative stress, inflammation, and metabolic abnormalities have been widely and deeply investigated as plausible mechanisms for its neuropathology. Aβ plaques and hyperphosphorylated tau aggregates, along with cognitive deficits and behavioral problems, are the hallmarks of the disease. Restoration of mitochondrial bioenergetics, prevention of oxidative stress, and diet and exercise seem to be effective in reducing Aβ and in ameliorating learning and memory problems. Many mitochondria-targeted antioxidants have been tested in AD and are currently in development. However, larger streamlined clinical studies are needed to provide hard evidence of benefits in AD. This review discusses the causative factors, as well as potential therapeutics employed in the treatment of AD.

Novel Biomarkers of Alzheimer's Disease: Based Upon N-methyl-D-aspartate Receptor Hypoactivation and Oxidative Stress

Early detection and prevention of Alzheimer’s disease (AD) is important. The current treatment for early AD is acetylcholine esterase inhibitors (AChEIs); however, the efficacy is poor. Besides, AChEI did not show efficacy in mild cognitive impairment (MCI). Beta-amyloid (Aβ) deposits have been regarded to be highly related to the pathogenesis of AD. However, many clinical trials aiming at the clearance of Aβ deposits failed to improve the cognitive decline of AD, even at its early phase. There should be other important mechanisms unproven in the course of AD and MCI. Feasible biomarkers for the diagnosis and treatment response of AD are lacking to date. The N-methyl-D-aspartate receptor (NMDAR) activation plays an important role in learning and memory. On the other hand, oxidative stress has been regarded to contribute to aging with the assumption that free radicals damage cell constituents and connective tissues. Our recent study found that an NMDAR enhancer, sodium benzoate (the pivotal inhibitor of D-amino acid oxidase [DAAO]), improved the cognitive and global function of patients with early-phase AD. Further, we found that peripheral DAAO levels were higher in patients with MCI and AD than healthy controls. We also found that sodium benzoate was able to change the activity of antioxidant. These pieces of evidence suggest that the NMDAR function is associated with anti-oxidation, and have potential to be biomarkers for the diagnosis and treatment response of AD.

Hippocampal transcriptome deconvolution reveals differences in cell architecture of not demented elderly subjects underwent late-life physical activity

Recent findings demonstrated that physical exercise has a powerful role in improving cognitive function and delaying age-associated neurological decline. However, to date, there is a lack of information regarding the effect of physical activity (PA) on brain cells architecture. In this paper, we hypothesized that PA could play a role in the transcriptional changes of genes that enrich the main cells of central nervous system (CNS). From NCBI, we selected a microarray dataset composed of the human hippocampi (GSE110298) from 23 cognitively intact clinical cases (NDHSs) (aged 87.4 ± 6.3 years) selected to from the Rush Memory and Aging Project (MAP). The significantly expressed genes, obtained comparing hippocampi from subjects who underwent Low Physical Activity (LPA) vs those who performed High Physical Activity (HPA), were overlapped with the main genes enriching the CNS cells, obtained from the public human brain single-cell RNA-sequencing dataset (GSE67835), in order to determine the respective weighted percentages of significantly expression genes modulation (WPSEG). In NDHSs underwent HPA, the WPSEG was higher for Neurons, Dendritic Development, Synaptic transmission genes and Axon Development. In addition, in NDHSs underwent LPA we observed high expression of genes enriching Oligodendrocytes, Microglia, and Endothelial cells. Furthermore, neurogenesis and the decreasing of the T cell-mediated inflammatory process were the two main molecular mechanisms activated in the brains of NDHSs underwent HPA. From our results, it is possible to conclude that, in elderly subjects, the transcriptional profile of CNS cells changes as a function of the PA conducted during life. Performing PA periodically supports the maintenance of the physiological balance of neuronal cells and, consequently, improves the quality of life of the elderly.

Association of cardiovascular disease and traditional cardiovascular risk factors with the incidence of dementia among patients with rheumatoid arthritis

OBJECTIVE

To determine the incidence of dementia in patients with rheumatoid arthritis (RA) 65 years and older, and compare the incidence of dementia in patients with RA with prevalent cardiovascular (CV) disease (CVD), CV risk factors but no prevalent CVD and neither (referent group).

METHODS

We analyzed claims data from the Center for Medicare & Medicaid Services (CMS) from 2006-2014. Eligibility criteria included continuous medical and pharmacy coverage for ≥ 12 months (baseline period 2006), > 2 RA diagnoses by a rheumatologist and at least 1 medication for RA. CVD and CV risk factors were identified using codes from the Chronic Condition Data Warehouse. Incident dementia was defined by 1 inpatient or 2 outpatient claims, or one dementia specific medication. Age-adjusted incident rates were calculated within each age strata. Univariate and multivariate Cox proportional hazard models were used to calculate Hazard Ratios (HR) and 95% confidence intervals.

RESULTS

Among 56,567 patients with RA, 11,789 (20.1%) incident cases of dementia were included in the main analysis. Age adjusted incident rates were high among all groups and increased with age. After adjustment for age, sex, comorbidities and baseline CV and RA medications, patients with CVD and CV risk factors between 65 and 74 years had an increased risk for incident dementia compared to those without CVD and without CV risk factors (HR 1.18 (95% CI 1.04-1.33) and HR 1.03 (95% CI 1.00-1.11), respectively). We observed a trend towards increased risk in patients between 75 and 84 years with CVD at baseline.

CONCLUSION

Patients with RA with both CVD and CV risk factors alone are at an increased risk for dementia compared to those with neither CVD nor CV risk factors; however, this risk is attenuated with increasing age. The impact of RA treatment and CV primary prevention strategies in the prevention of dementia in patients with RA warrants further studies.

The role of innate immunity in Alzheimer's disease

The amyloid hypothesis has dominated Alzheimer's disease (AD) research for almost 30 years. This hypothesis hinges on the predominant clinical role of the amyloid beta (Aβ) peptide in propagating neurofibrillary tangles (NFTs) and eventual cognitive impairment in AD. Recent research in the AD field has identified the brain-resident macrophages, known as microglia, and their receptors as integral regulators of both the initiation and propagation of inflammation, Aβ accumulation, neuronal loss, and memory decline in AD. Emerging studies have also begun to reveal critical roles for distinct innate immune pathways in AD pathogenesis, which has led to great interest in harnessing the innate immune response as a therapeutic strategy to treat AD. In this review, we will highlight recent advancements in our understanding of innate immunity and inflammation in AD onset and progression. Additionally, there has been mounting evidence suggesting pivotal contributions of environmental factors and lifestyle choices in AD pathogenesis. Therefore, we will also discuss recent findings, suggesting that many of these AD risk factors influence AD progression via modulation of microglia and immune responses.

The effects of voluntary running on cerebrovascular morphology and spatial short-term memory in a mouse model of amyloidosis

Physical activity has been correlated with a reduced risk of cognitive decline, including that associated with vascular dementia, mild cognitive impairment (MCI) and Alzheimer's disease (AD); recent literature suggests this may in part result from benefits to the cerebrovascular network. Using a transgenic (Tg) mouse model of AD, we evaluated the effect of running on cortical and hippocampal vascular morphology, cerebral amyloid angiopathy, amyloid plaque load, and spatial memory. TgCRND8 mice present with progressive amyloid pathology, advancing from the cortex to the hippocampus in a time-dependent manner. We postulated that the characteristic progression of pathology could lead to differential, time-dependent effects of physical activity on vascular morphology in these brain regions at 6 months of age. We used two-photon fluorescent microscopy and 3D vessel tracking to characterize vascular and amyloid pathology in sedentary TgCRND8 mice compared those who have a history of physical activity (unlimited access to a running wheel, from 3 to 6 months of age). In sedentary TgCRND8 mice, capillary density was found to be lower in the cortex and higher in the hippocampus compared to non-transgenic (nonTg) littermates. Capillary length, vessel branching, and non-capillary vessel tortuosity were also higher in the hippocampus of sedentary TgCRND8 compared to nonTg mice. Three months of voluntary running resulted in normalizing cortical and hippocampal microvascular morphology, with no significant difference between TgCRND8 and nonTg mice. The benefits of physical activity on cortical and hippocampal vasculature in 6-month old TgCRND8 mice were not paralleled by significant changes on parenchymal and cerebral amyloid pathology. Short-term spatial memory- as evaluated by performance in the Y-maze- was significantly improved in running compared to sedentary TgCRND8 mice. These results suggest that long-term voluntary running contributes to the maintenance of vascular morphology and spatial memory in TgCRND8 mice, even in the absence of an effect on amyloid pathology.

Protective effect of maternal exercise against amyloid-β neurotoxicity in the male rat offspring's cerebellum

The Developmental Origins of Health and Disease (DOHaD) states that intrauterine maternal environment influences postnatal life by programming offspring's metabolism. Intrauterine milieu induced by exercise during pregnancy promotes long-lasting benefits to the offspring's health and seems to offer some resistance against chronic diseases in adult life. Alzheimer's disease is a public health concern with limited treatment options. In the present study, we assessed the potential of maternal exercise during pregnancy in long-term programming of young adult male rat offspring's cerebellar metabolism in conferring neuroprotection against amyloid-β (Aβ) neurotoxicity. Female Wistar rats were submitted to a swimming protocol 1 week prior mating and throughout pregnancy (five sessions/a week lasting 30 min). Aβ oligomers were infused bilaterally in the brain ventricles of 60-day-old male offspring. Fourteen days after surgery, we measured parameters related to redox state, mitochondrial function, and the immunocontent of proteins related to synaptic function. We found that maternal exercise during pregnancy attenuated several parameters in the offspring's male rat cerebellum, such as the reactive species rise, the increase of inducible nitric oxide synthase immunocontent and tau phosphorylation induced by Aβ oligomers, increased mitochondrial fission indicated by dynamin-related protein 1 (DRP1), and protein oxidation identified by carbonylation. Strikingly, we find that maternal exercise promotes changes in the rat offspring's cerebellum that are still evident in young adult life. These favorable neurochemical changes in offspring's cerebellum induced by maternal exercise may contribute to a protective phenotype against Aβ-induced neurotoxicity in young adult male rat offspring.

The effect of physical activity on cognition relative to APOE genotype (PAAD-2): study protocol for a phase II randomized control trial

BACKGROUND

By 2050, the prevalence of Alzheimer's disease (AD) in the United States is predicted to reach 13.8 million. Despite worldwide research efforts, a cure for AD has not been identified. Thus, it is critical to identify preventive strategies that can reduce the risk of or delay the onset of AD. Physical activity (PA) has potential in this regard. This randomized clinical trial aims to (a) test the causal relationship between PA and AD-associated cognitive function for persons with a family history of AD (FH+), (b) determine the moderating role of apolipoprotein epsilon 4 (APOE4) carrier status on cognition, and (c) assess cerebral structure, cerebral function, and putative biomarkers as mediators of the effects of PA on cognition.

METHODS

We are recruiting cognitively normal, middle aged (40-65 years) sedentary adults with FH+. Participants are randomly assigned to a 12-month PA intervention for 3 days/week or to a control group maintaining their normal lifestyle. Saliva samples are taken at pre-test to determine APOE genotype. At pre-, mid-, and post-tests, participants complete a series of cognitive tests to assess information-processing speed, verbal and visual episodic memory, constructional praxis, mnemonic discrimination, and higher-order executive functions. At pre- and post-tests, brain imaging and blood biomarkers are assessed.

DISCUSSION

We hypothesize that 1) the PA group will demonstrate improved cognition compared with controls; 2) PA-derived cognitive changes will be moderated by APOE4 status; and 3) PA-induced changes in neural and blood biomarkers will contribute to cognitive changes and differ as a function of APOE4 status. Our results may provide important insights into the potential of PA to preserve neurocognitive function in people with a heightened risk of AD due to FH+ and as moderated by APOE4 status. By using sophisticated analytic techniques to assess APOE as a moderator and neurobiological mechanisms as mediators across trajectories of cognitive change in response to PA, we will advance our understanding of the potential of PA in protecting against AD.

TRIAL REGISTRATION

ClinicalTrials.gov NCT03876314. Registered March 15, 2019.

Protective actions of exercise-related FNDC5/Irisin in memory and Alzheimer's disease

The proportion of elderly populations is rapidly booming, and human lifespan has considerably increased in the past century because of scientific and medical advances. However, the winds of change brought by the 21st century made sedentarism one of the factors that renders the brain vulnerable to age-related chronic diseases, such as Alzheimer's disease (AD). Conversely, physical exercise has been shown to stimulate molecular mechanisms beneficial to cognition. Here, we review evidence showing the positive effects of physical exercise in the brain. We further discuss recent evidence that irisin, a myokine stimulated by physical exercise derived from fibronectin type III domain-containing protein 5 (FNDC5) transmembrane protein, has neuroprotective actions in the brain. Lastly, we highlight the importance of the crosstalk between the periphery and the brain in cognition and the therapeutic potential of FNDC5/irisin in AD.

Therapeutic noninvasive brain stimulation in Alzheimer's disease and related dementias

PURPOSE OF REVIEW

Alzheimer's disease is a progressive neurodegenerative disease without effective pharmacological treatment. Noninvasive brain stimulation (NIBS) techniques, such as repetitive transcranial magnetic stimulation (TMS) and transcranial electrical stimulation (tES), are increasingly being investigated for their potential to ameliorate the symptoms of Alzheimer's disease and related dementias (ADRD).

RECENT FINDINGS

A comprehensive literature review for primary research reports that investigated the ability of TMS/tES to improve cognition in ADRD patients yielded a total of 20 reports since 2016. Eight studies used repetitive TMS and 12 used transcranial direct current stimulation, the most common form of tES. Eight of the studies combined NIBS with cognitive training. Promising results should encourage continued investigation, however there is currently insufficient evidence to support widespread adoption of NIBS-based clinical treatments for ADRD.

SUMMARY

NIBS remains an active area of investigation for treatment of ADRD, though the predominance of small, heterogeneous, proof-of-principle studies precludes definitive conclusions. We propose the establishment of a consortium to achieve the benefits of large-scale, controlled studies using biomarker-based diagnostic characterization of participants, development of neurophysiological markers to verify target engagement, and standardization of parameters.

Voluntary exercise reduces plasma cortisol levels and improves transitory memory impairment in young and aged Octodon degus

Sleep deprivation (SD) has been reported to induce transient cognitive impairment in functional domains commonly affected in dementia, including memory. Indeed, sleep disturbance has been proposed as an early marker for Alzheimer's disease (AD). SD emulates many aging-related modifications, including important memory dysfunctions possibly caused by triggers of stress such as cortisol. Although exercise is widely assumed to be beneficial for overall health, only recently has the research community focused its attention on its possible effects on brain functions such as cognition. Octodon degus (O. degus) is a recent rodent model considered suitable for the study of neurodegenerative diseases, since it spontaneously develops several histopathological hallmarks observed in AD. We aimed to uncover the interaction between stress, exercise, age and transient memory impairments after SD insult. In this study, animals had free individual access to wheels to practice voluntary exercise. The Barnes Maze (BM) task was conducted with young and aged O. degus animals after combining voluntary exercise and either normal sleep or SD. Plasma cortisol levels were measured after each condition. SD impaired hippocampus-dependent memory in both young and old animals, while cortisol levels did not significantly differ between non-SD and SD animals. However, voluntary exercise for 45 days improved the cognitive impairment caused by SD compared with the control condition. Moreover, voluntary exercise decreased plasma cortisol levels in both conditions, independently of the age.

The Effects of Maternal Atrazine Exposure and Swimming Training on Spatial Learning Memory and Hippocampal Morphology in Offspring Male Rats via PSD95/NR2B Signaling Pathway

Atrazine (ATR), a widely used herbicide, has been previously shown to damage spatial memory capability and the hippocampus of male rats during the development. It has also been indicated that physical exercise can improve learning and memory in both humans and animals, as a neuroprotective method. Our aim here was to investigate the effect of maternal ATR exposure during gestation and lactation on spatial learning and memory function and hippocampal morphology in offspring and to further evaluate the neuroprotective effect of swimming training and identify possible related learning and memory signaling pathways. Using Sprague-Dawley rats, we examined behavioral and molecular biology effects associated with maternal ATR exposure, as well as the effects of 8 or 28 days swimming training. Maternal exposure to ATR was found to impair spatial learning and memory by behavioral test, damage the hippocampal morphology, and reduce related genes and proteins expression of learning and memory in the hippocampus. The extended, 28 days, period of swimming training produced a greater amelioration of the adverse effects of ATR exposure than the shorter, 8 days, training period. Our results suggest that maternal ATR exposure may damage the spatial learning and memory of offspring male rats via PSD95/NR2B signaling pathway. The negative effect of ATR could be at least partially reversed by swimming training, pointing to a potential neuroprotective role of physical exercise in nervous system diseases accompanying by learning and memory deficit.

The Neuroprotective Effects of Exercise: Maintaining a Healthy Brain Throughout Aging

Physical activity plays an essential role in maintaining a healthy body, yet it also provides unique benefits for the vascular and cellular systems that sustain a healthy brain. While the benefit of exercise has been observed in humans of all ages, the availability of preclinical models has permitted systematic investigations into the mechanisms by which exercise supports and protects the brain. Over the past twenty-five years, rodent models have shown that increased physical activity elevates neurotrophic factors in the hippocampal and cortical areas, facilitating neurotransmission throughout the brain. Increased physical activity (such as by the voluntary use of a running wheel or regular, timed sessions on a treadmill) also promotes proliferation, maturation and survival of cells in the dentate gyrus, contributing to the process of adult hippocampal neurogenesis. In this way, rodent studies have tremendous value as they demonstrate that an 'active lifestyle' has the capacity to ameliorate a number of age-related changes in the brain, including the decline in adult neurogenesis. Moreover, these studies have shown that greater physical activity may protect the brain health into advanced age through a number of complimentary mechanisms: in addition to upregulating factors in pro-survival neurotrophic pathways and enhancing synaptic plasticity, increased physical activity promotes brain health by supporting the cerebrovasculature, sustaining the integrity of the blood-brain barrier, increasing glymphatic clearance and proteolytic degradation of amyloid beta species, and regulating microglia activation. Collectively, preclinical studies demonstrate that exercise initiates diverse and powerful neuroprotective pathways that may converge to promote continued brain health into old age. This review will draw on both seminal and current literature that highlights mechanisms by which exercise supports the functioning of the brain, and aids in its protection.

Technology-Based Behavioral Interventions for Daily Activities and Supported Ambulation in People With Alzheimer's Disease

OBJECTIVES

These 2 studies evaluated technology-based behavioral interventions for promoting daily activities and supported ambulation in people with mild-to-moderate and moderate-to-severe Alzheimer's disease, respectively.

METHODS

Study 1 included 8 participants who were taught to start and carry out daily activities on their own using a tablet or smartphone device, which provided activity reminders, step instructions, and praise. Study 2 included 9 participants who were taught to engage in brief periods of ambulation using a walker combined with a tilt microswitch and a notebook computer, which monitored step responses and provided stimulation and prompts.

RESULTS

The participants of study 1 succeeded in starting the activities independently and carrying them out accurately. The participants of study 2 largely increased their ambulation levels and also showed signs of positive involvement (eg, smiles and verbalizations).

CONCLUSION

The aforementioned technology-based interventions may represent practical means for supporting people with Alzheimer's disease.

Accounting for Social Processes in the Development of Diagnostic Classification Systems: Commentary on the “Standards and Guidelines for the Development of Diagnostic Nomenclatures and Alternatives in Mental Health Research and Practice”

Diagnostic classifications of mental disorders are complex systems that integrate both scientific and social priorities. The Task Force on Developing Humanistic Approaches to Psychological Diagnosis of the Society for Humanistic Psychology has released a set of guidelines intended to guide the development of mental health classifications. This commentary argues that the attention paid in the guidelines to social processes is a desirable and inherent component of the development of any classification. Social influences regarding the definition of the concepts and the processes by which people develop them are integrally intertwined, contrary to the common view that nonscientific factors should be excluded from classification systems as much as possible. These guidelines offer a much needed resource for developing future mental health classifications.

The Dose-Dependent Effects of Vascular Risk Factors on Dynamic Compensatory Neural Processes in Mild Cognitive Impairment

Background/Objectives: Mild cognitive impairment (MCI) has been associated with risk for Alzheimer's Disease (AD). Previous investigations have suggested that vascular risk factors (VRFs) were associated with cognitive decline and AD pathogenesis, and the intervention of VRFs may be a possible way to prevent dementia. However, in MCI, little is known about the potential impacts of VRFs on neural networks and their neural substrates, which may be a neuroimaging biomarker of the disease progression.

Methods: 128 elderly Han Chinese participants (67 MCI subjects and 61 matched normal elderly) with or without VRFs (hypertension, diabetes mellitus, hypercholesterolemia, smoking and alcohol drinking) underwent the resting-state functional magnetic resonance imaging (fMRI) and neuropsychological tests. We obtained the default mode network (DMN) to identify alterations in MCI with the varying number of the VRF and analyzed the significant correlation with behavioral performance.

Results: The effects of VRF on the DMN were primarily in bilateral dorsolateral prefrontal cortex (DLPFC) (i.e., middle frontal gyrus). Normal elderly showed the gradually increased functional activity of DLPFC, while a fluctuant activation of DLPFC was displayed in MCI with the growing number of the VRF. Interestingly, the left DLPFC further displayed significantly dynamic correlation with executive function as the variation of VRF loading. Initial level of compensation was observed in normal aging and none-vascular risk factor (NVRF) MCI, while these compensatory neural processes were suppressed in One-VRF MCI and were subsequently re-aroused in Over-One-VRF MCI.

Conclusions: These findings suggested that the dose-dependent effects of VRF on DLPFC were highlighted in MCI, and the dynamic compensatory neural processes that fluctuated along with variations of VRF loading could be key role in the progression of MCI.

Memorcise and Alzheimer's disease

Alzheimer's disease (AD) is a debilitating disease influencing a multitude of outcomes, including memory function. Recent work suggests that memory may be influenced by exercise ('memorcise'), even among those with AD. The present narrative review details (1) the underlying mechanisms of AD; (2) whether exercise has a protective effect in preventing AD; (3) the mechanisms through which exercise may help to prevent AD; (4) the mechanisms through which exercise may help attenuate the progression of AD severity among those with existing AD; (5) the effects and mechanisms through which exercise is associated with memory among those with existing AD; and (6) exercise recommendations for those with existing AD. Such an understanding will aid clinicians in their ability to use exercise as a potential behavioral strategy to help prevent and treat AD.

Physical activity, visual impairment, and eye disease

Numerous studies have demonstrated physical activity is a strong factor in overall health and well-being, and a growing body of literature, reviewed herein, suggests that several eye conditions, including glaucoma, age-related macular degeneration, and diabetic retinopathy, are associated with lower activity levels. Likewise, physical activity levels are lower in persons with worse vision. Research in this area has utilized both self-reported physical activity measures as well as objective measures of activity (i.e., accelerometers), each of which have their own strengths and limitations. Putative mechanisms explaining the association of various eye conditions with physical activity are discussed. It is possible that activity restriction occurs as a downstream consequence of eye disease/visual impairment, that activity restriction causes eye disease/visual impairment, or that causality is bidirectional; evidence supporting each of these theories is put forth. An improved understanding of the relationship between physical activity and eye disease will highlight potential secondary health risks resulting from eye disease, and can help determine whether activity might serve as a readily available preventative measure to prevent specific eye conditions.

Effect of physical activity on cognitive flexibility, depression and RBD in healthy elderly

OBJECTIVE

The prevalence of Alzheimer's disease and Parkinson's disease increases with the raising number of elderly, which will be a challenging situation for the healthcare systems and society in the future. There is evidence that there are modifiable risk-factors e.g. physical activity for these diseases. Here, we study the interaction between sports inactivity with prodromal markers for neurodegeneration.

PATIENTS AND METHODS

We investigated 667 neurologically healthy individuals cross-sectional and a subgroup longitudinal over six years. Participants were stratified by their weekly sports activity. Prodromal markers (depression and REM sleep behaviour disorder (RBD)) as well as single and dual-tasking parameters and cognitive parameters were compared between the groups.

RESULTS

At baseline, sports activity was associated with lower BDI scores, lower occurrence of depressive syndrome and RBD, compared to sports inactivity. Further, active participants were faster in cognitive tasks associated with working memory and attention (Trail Making test part-A; TMT-B, ΔTMT-B-A) and better in gait and cognition parameters (single tasks and dual tasks) but not with overall cognition as measured with the MMSE. The association between physical inactivity and depression as well as TMT was present after six years.

CONCLUSION

We found that sports activity has a positive effect on cognitive flexibility, depressive symptoms and sleep which are all signs for a possible ongoing neurodegenerative process. Therefore, our results strengthen the potential role of sports activity as a positive disease modifier.

Exercise decreases BACE and APP levels in the hippocampus of a rat model of Alzheimer's disease

We investigated the effect of treadmill exercise training on the levels of Alzheimer's disease (AD)-related protein molecules in the DG and CA1 areas of a rat model of AD, i.c.v. infusion of Aβ1-42 peptide, 2weeks (250pmol/day). Aβ infusion markedly increased protein levels of amyloid precursor protein (APP), the secretase beta-site APP cleaving enzyme-1 (BACE-1) and Aβ in the CA1 and DG areas. The results also revealed that 4weeks of treadmill exercise prevented the increase in the levels of APP, BACE-1 and Aβ proteins in both hippocampal areas. Exercise, however, did not affect the levels of these proteins in normal rats. We suggest that exercise might be changing the equilibrium of APP processing pathway towards the nonpathogenic pathway most probably via increasing BDNF levels in the brain of AD model.

Study on Lentivirus-Mediated ABCA7 Improves Neurocognitive Function and Related Mechanisms in the C57BL/6 Mouse Model of Alzheimer's Disease

ATP-binding cassette transporter A7 (ABCA7) is expressed in the hippocampus and cortex of the brain and was confirmed to be involved in the development of Alzheimer's disease (AD). Previous studies have demonstrated that ABCA7 regulated Aβ production, lipid transport, leading to AD characteristic pathological changes. However, the role and mechanism of ABCA7 in the context of AD needs further research. We augmented the expression of ABCA7 using lentiviral vector carrying ABCA7 gene to investigate the effect of ABCA7 overexpression on AD mice; then, we further explored the underlying mechanism in vitro. In the present study, ABCA7 was expressed successfully in the hippocampus of AD mice through lentiviral vector mediating ABCA7 gene; we showed that ABCA7 overexpression can effectively improve cognitive behavior of AD mice and diminished Aβ production; meanwhile, ABCA7 overexpression significantly relieved the neurotoxicity of Aβ by promoting cell viability and reducing endoplasmic reticulum stress. In conclusion, our findings showed that ABCA7 had obvious anti-Aβ effect and appeared to improve cognitive function of AD mice. Our results provided a new thought and basic scientific data for the clinical treatment of AD.

Alzheimer's Disease as the Product of a Progressive Energy Deficiency Syndrome in the Central Nervous System: The Neuroenergetic Hypothesis

The decreased availability of metabolizable energy resources in the central nervous system is hypothesized to be a key factor in the pathogenesis of Alzheimer's disease. More specifically, the age-related decline in the ability of glucose to cross the blood-brain barrier creates a metabolic stress that shifts the normal, benign processing of amyloid-β protein precursor toward pathways associated with the production of amyloid-β plaques and tau-containing neurofibrillary tangles that are characteristic of the disease. The neuroenergetic hypothesis provides insight into the etiology of Alzheimer's disease and illuminates new approaches for diagnosis, monitoring, and treatment.