Plasma REST: a novel candidate biomarker of Alzheimer's disease is modified by psychological intervention in an at-risk population

The Effect of Mindfulness-Based Interventions on Mental Health and Cognitive Function in Older Adults: A Systematic Review and Meta-Analysis

OBJECTIVES

To assess whether mindfulness-based interventions (MBIs) affect mental health and cognitive abilities in older adults.

METHODS

A systematic search was performed in PubMed, SCOPUS, Web of Science, and Google Scholar up to June 2023. Weight mean difference and 95% confidence intervals were provided as summary statistics.

RESULTS

In total, 26 articles were eligible. Overall, MBIs showed a statistically significant improvement in depression, anxiety, quality of life, and working memory compared to controls. However, no significant effects of MBIs on other cognitive parameters were found. In moderator analysis, less than eight weeks of MBIs showed greater improvement in anxiety and quality of life than longer periods. There was no evidence for publication bias.

DISCUSSION

Mindfulness-based interventions can be an encouraging alternative in place of conventional treatments in improving depression, anxiety, quality of life and working memory in cognition among older adults. However, findings strongly recommend future research to have definite conclusion.

Identification of Inhibitors of the Disease-Associated Protein Phosphatase Scp1 Using Antibody Mimetic Molecules

Protein phosphorylation is a prevalent translational modification, and its dysregulation has been implicated in various diseases, including cancer. Despite its significance, there is a lack of specific inhibitors of the FCP/SCP-type Ser/Thr protein phosphatase Scp1, characterized by high specificity and affinity. In this study, we focused on adnectin, an antibody-mimetic protein, aiming to identify Scp1-specific binding molecules with a broad binding surface that target the substrate-recognition site of Scp1. Biopanning of Scp1 was performed using an adnectin-presenting phage library with a randomized FG loop. We succeeded in identifying FG-1Adn, which showed high affinity and specificity for Scp1. Ala scanning analysis of the Scp1-binding sequence in relation to the FG-1 peptide revealed that hydrophobic residues, including aromatic amino acids, play important roles in Scp1 recognition. Furthermore, FG-1Adn was found to co-localize with Scp1 in cells, especially on the plasma membrane. In addition, Western blotting analysis showed that FG-1Adn increased the phosphorylation level of the target protein of Scp1 in cells, indicating that FG-1Adn can inhibit the function of Scp1. These results suggest that FG-1Adn can be used as a specific inhibitor of Scp1.

From Recognition to Remedy: The Significance of Biomarkers in Neurodegenerative Disease Pathology

With the inexorable aging of the global populace, neurodegenerative diseases (NDs) like Alzheimer's disease (AD), Parkinson's disease (PD), and amyotrophic lateral sclerosis (ALS) pose escalating challenges, which are underscored by their socioeconomic repercussions. A pivotal aspect in addressing these challenges lies in the elucidation and application of biomarkers for timely diagnosis, vigilant monitoring, and effective treatment modalities. This review delineates the quintessence of biomarkers in the realm of NDs, elucidating various classifications and their indispensable roles. Particularly, the quest for novel biomarkers in AD, transcending traditional markers in PD, and the frontier of biomarker research in ALS are scrutinized. Emergent susceptibility and trait markers herald a new era of personalized medicine, promising enhanced treatment initiation especially in cases of SOD1-ALS. The discourse extends to diagnostic and state markers, revolutionizing early detection and monitoring, alongside progression markers that unveil the trajectory of NDs, propelling forward the potential for tailored interventions. The synergy between burgeoning technologies and innovative techniques like -omics, histologic assessments, and imaging is spotlighted, underscoring their pivotal roles in biomarker discovery. Reflecting on the progress hitherto, the review underscores the exigent need for multidisciplinary collaborations to surmount the challenges ahead, accelerate biomarker discovery, and herald a new epoch of understanding and managing NDs. Through a panoramic lens, this article endeavors to provide a comprehensive insight into the burgeoning field of biomarkers in NDs, spotlighting the promise they hold in transforming the diagnostic landscape, enhancing disease management, and illuminating the pathway toward efficacious therapeutic interventions.

Early Diagnosis of Alzheimer's Disease with Blood Test; Tempting but Challenging

The increasing prevalence of Alzheimer's disease (AD) has led to a health crisis. According to official statistics, more than 55 million people globally have AD or other types of dementia, making it the sixth leading cause of death. It is still difficult to diagnose AD and there is no definitive diagnosis yet; post-mortem autopsy is still the only definite method. Moreover, clinical manifestations occur very late in the course of disease progression; therefore, profound irreversible changes have already occurred when the disease manifests. Studies have shown that in the preclinical stage of AD, changes in some biomarkers are measurable prior to any neurological damage or other symptoms. Hence, creating a reliable, fast, and affordable method capable of detecting AD in early stage has attracted the most attention. Seeking clinically applicable, inexpensive, less invasive, and much more easily accessible biomarkers for early diagnosis of AD, blood-based biomarkers (BBBs) seem to be an ideal option. This review is an inclusive report of BBBs that have been shown to be altered in the course of AD progression. The aim of this report is to provide comprehensive insight into the research status of early detection of AD based on BBBs.

Plasma microRNAs as potential biomarkers in early Alzheimer disease expression

The microRNAs (miRNAs) are potential biomarkers for complex pathologies due to their involvement in the regulation of several pathways. Alzheimer Disease (AD) requires new biomarkers in minimally invasive samples that allow an early diagnosis. The aim of this work is to study miRNAS as potential AD biomarkers and their role in the pathology development. In this study, participants (n = 46) were classified into mild cognitive impairment due to AD (MCI-AD, n = 19), preclinical AD (n = 8) and healthy elderly controls (n = 19), according to CSF biomarkers levels (amyloid β42, total tau, phosphorylated tau) and neuropsychological assessment. Then, plasma miRNAomic expression profiles were analysed by Next Generation Sequencing. Finally, the selected miRNAs were validated by quantitative PCR (q-PCR). A panel of 11 miRNAs was selected from omics expression analysis, and 8 of them were validated by q-PCR. Individually, they did not show statistically significant differences among participant groups. However, a multivariate model including these 8 miRNAs revealed a potential association with AD for three of them. Specifically, relatively lower expression levels of miR-92a-3p and miR-486-5p are observed in AD patients, and relatively higher levels of miR-29a-3p are observed in AD patients. These biomarkers could be involved in the regulation of pathways such as synaptic transmission, structural functions, cell signalling and metabolism or transcription regulation. Some plasma miRNAs (miRNA-92a-3p, miRNA-486-5p, miRNA-29a-3p) are slightly dysregulated in AD, being potential biomarkers of the pathology. However, more studies with a large sample size should be carried out to verify these results, as well as to further investigate the mechanisms of action of these miRNAs.

Plasma repressor element 1-silencing transcription factor levels are decreased in patients with Alzheimer's disease

Background

Repressor element 1-silencing transcription (REST)/neuron-restrictive silencer factor is considered a new therapeutic target for neurodegenerative disorders such as Alzheimer’s disease (AD). However, the relationship between AD and REST remains unclear. This study aimed to 1) examine plasma REST levels and REST gene levels in AD patients and 2) further explore the pathological relationships between REST protein levels and cognitive decline in clinical conditions, including medial temporal lobe atrophy.

Methods

Participants (n = 252, mean age 68.95 ± 8.78 years) were recruited in Beijing, China, and then divided into a normal cognition (NC) group (n = 89), an amnestic mild cognitive impairment (aMCI) group (n = 79), and an AD dementia group (n = 84) according to diagnostic criteria. All participants underwent neuropsychological assessments, laboratory tests, and neuroimaging scans (magnetic resonance imaging) at baseline. Plasma REST protein levels and the distribution of REST single nucleotide polymorphisms (SNPs) were compared among the three groups. Correlations between cognitive function, neuro-imaging results, and REST levels were determined by a multivariate linear regression analysis.

Results

The plasma REST levels in both the NC group (430.30 ± 303.43)pg/ml and aMCI group (414.27 ± 263.39)pg/ml were significantly higher than that in the AD dementia group (NC vs AD dementia group, p = 0.034; aMCI vs AD dementia group, p = 0.033). There was no significant difference between the NC and aMCI groups (p = 0.948). No significant difference was found among the three groups regarding the genotype distribution (rs2227902 and rs3976529 SNPs) of the REST gene. The REST level was correlated with the left medial temporal lobe atrophy index (r = 0.306, p = 0.023). After 6 months of follow-up, the REST level in the NC group was positively correlated with the change in the Mini-Mental State Examination score (r = 0.289, p = 0.02).

Conclusion

The plasma REST protein level is decreased in AD dementia patients, which is associated with memory impairment and left temporal lobe atrophy and may have potential value for clinical diagnosis of AD dementia.

Advances in Recapitulating Alzheimer's Disease Phenotypes Using Human Induced Pluripotent Stem Cell-Based In Vitro Models

Alzheimer's disease (AD) is an incurable neurodegenerative disorder and the leading cause of death among older individuals. Available treatment strategies only temporarily mitigate symptoms without modifying disease progression. Recent studies revealed the multifaceted neurobiology of AD and shifted the target of drug development. Established animal models of AD are mostly tailored to yield a subset of disease phenotypes, which do not recapitulate the complexity of sporadic late-onset AD, the most common form of the disease. The use of human induced pluripotent stem cells (HiPSCs) offers unique opportunities to fill these gaps. Emerging technology allows the development of disease models that recapitulate a brain-like microenvironment using patient-derived cells. These models retain the individual's unraveled genetic background, yielding clinically relevant disease phenotypes and enabling cost-effective, high-throughput studies for drug discovery. Here, we review the development of various HiPSC-based models to study AD mechanisms and their application in drug discovery.

Modulation of Amyloid-β and Tau in Alzheimer's Disease Plasma Neuronal-Derived Extracellular Vesicles by Cerebrolysin® and Donepezil

BACKGROUND

Plasma neuronal-derived extracellular vesicles (NDEV) contain proteins of pathological, diagnostic, and therapeutic relevance.

OBJECTIVE

We investigated the associations of six plasma NDEV markers with Alzheimer's disease (AD) severity, cognition and functioning, and changes in these biomarkers after Cerebrolysin®, donepezil, and a combination therapy in AD.

METHODS

Plasma NDEV levels of Aβ42, total tau, P-T181-tau, P-S393-tau, neurogranin, and REST were determined in: 1) 116 mild to advanced AD patients and in 20 control subjects; 2) 110 AD patients treated with Cerebrolysin®, donepezil, or combination therapy in a randomized clinical trial (RCT). Samples for NDEV determinations were obtained at baseline in the NDEV study and at baseline and study endpoint in the RCT. Cognition and functioning were assessed at the same time points.

RESULTS

NDEV levels of Aβ42, total tau, P-T181-tau, and P-S393-tau were higher and those of neurogranin and REST were lower in mild-to-moderate AD than in controls (p < 0.05 to p < 0.001). NDEV total tau, neurogranin, and REST increased with AD severity (p < 0.05 to p < 0.001). NDEV Aβ42 and P-T181-tau correlated negatively with serum BDNF (p < 0.05), and total-tau levels were associated to plasma TNF-α (p < 0.01) and cognitive impairment (p < 0.05). Combination therapy reduced NDEV Aβ42 with respect to monotherapies (p < 0.05); and NDEV total tau, P-T181-tau, and P-S396-tau were decreased in Cerebrolysin-treated patients compared to those on donepezil monotherapy (p < 0.05).

CONCLUSION

The present results demonstrate the utility of NDEV determinations of pathologic and synaptic proteins as effective AD biomarkers, as markers of AD severity, and as potential tools for monitoring the effects of anti-AD drugs.

The potential roles of excitatory-inhibitory imbalances and the repressor element-1 silencing transcription factor in aging and aging-associated diseases

Disruptions to the central excitatory-inhibitory (E/I) balance are thought to be related to aging and underlie a host of neural pathologies, including Alzheimer's disease. Aging may induce an increase in excitatory signaling, causing an E/I imbalance, which has been linked to shorter lifespans in mice, flies, and worms. In humans, extended longevity correlates to greater repression of genes involved in excitatory neurotransmission. The repressor element-1 silencing transcription factor (REST) is a master regulator in neural cells and is believed to be upregulated with senescent stimuli, whereupon it counters hyperexcitability, insulin/insulin-like signaling pathway activity, oxidative stress, and neurodegeneration. This review examines the putative mechanisms that distort the E/I balance with aging and neurodegeneration, and the putative roles of REST in maintaining neuronal homeostasis.

A Systematic Review of Mindfulness-Based Interventions for Patients with Mild Cognitive Impairment or Dementia and Caregivers

The aim of this article was to systematically review the quality and efficacy of the current evidence for mindfulness-based interventions (MBIs) in patients with mild cognitive impairment (MCI), patients with dementia (PwD), and their caregivers. We identified 20 randomized controlled trials (RCTs) (11 for patients, 9 for caregivers) published in the last 15 years. Evidence suggested that MBIs are highly acceptable and credible treatments for patients with MCI, PwD and caregivers. Specifically, for PwD, the results indicated that the magnitude of post-treatment effects of MBIs are in the medium to large range for psychosocial outcomes, and in the small to medium range for cognitive functioning; however, treatment effects on dementia biomarkers were mixed, ranging from small to large, depending on the outcome measure. Findings also evidenced salutary effects of MBIs for caregivers of PwD, with post-treatment effects ranging from medium to large for caregiver stress and burden and large effects for quality of life, and mixed outcomes for cognitive functioning, with effects in the small to large range. However, confidence in these findings is relatively limited due to methodological limitations, especially in terms of poor consistency in intervention strategies, outcome measures, and other key criteria across studies. To better assess the value of MBIs for these populations and optimize treatment outcomes, we recommend further research with improved study methodology (e.g., multi-method assessment, universal criterion and outcome measures, use of active control groups, larger sample sizes, long-term follow-up) to replicate current findings and enhance our understanding of underlying treatment mechanisms of MBIs.

The adaptive aging brain

The aging brain is shaped by many structural and functional alterations. Recent cross-disciplinary efforts have uncovered powerful and integrated adaptive mechanisms that promote brain health and prevent functional decline during aging. Here, we review some of the most robust adaptive mechanisms and how they can be engaged to protect, and restore the aging brain.

REST/NRSF deficiency impairs autophagy and leads to cellular senescence in neurons

During aging, brain performances decline. Cellular senescence is one of the aging drivers and a key feature of a variety of human age‐related disorders. The transcriptional repressor RE1‐silencing transcription factor (REST) has been associated with aging and higher risk of neurodegenerative disorders. However, how REST contributes to the senescence program and functional impairment remains largely unknown. Here, we report that REST is essential to prevent the senescence phenotype in primary mouse neurons. REST deficiency causes failure of autophagy and loss of proteostasis, increased oxidative stress, and higher rate of cell death. Re‐establishment of autophagy reverses the main hallmarks of senescence. Our data indicate that REST has a protective role in physiological aging by regulating the autophagic flux and the senescence program in neurons, with implications for neurological disorders associated with aging.

Centenarians as models of healthy aging: Example of REST

Centenarians are a group of individuals exhibiting extreme longevity, who are characterized by a remarkable compression of morbidity. Therefore, centenarians have been postulated as a model of healthy aging. Different approaches have been used to decipher the biology and genetics of centenarians in order to identify key anti-aging pathways. The majority of studies have taken advantage of blood samples to perform their analysis. Besides, a recent study in human brain samples deciphered the transcription factor REST (Repressor Element-1 Silencing Transcription Factor) as an important player of extreme longevity and cognitive activity. This study goes from human to animal models and revealed that REST acts as an epigenetic regulator of neuronal homeostasis, to control aging and longevity. The aim of this view point is to summarize recent literature describing genetic and epigenetic factors, as well as molecular pathways associated with centenarians and the biology of aging. We will pay particular attention to the impact of REST in centenarians and longevity.

Repressor element 1 silencing transcription factor /neuron-restrictive silencing factor (REST/NRSF) in social stress and depression

Extreme stress is closely linked with symptoms of depression. Chronic social stress can cause structural and functional changes in the brain. These changes are associated with dysfunction of neuroprotective signalling that is necessary for cell survival, growth, and maturation. Reduced neuronal numbers and volume of brain regions have been found in depressed patients, which may be caused by decreased cell survival and increased cell death. Elucidating the mechanism underlying the degeneration of the neuroprotective system in social stress-induced depression is important for developing neuroprotective measures. The Repressor Element 1 Silencing Transcription Factor (REST) also known as Neuron-Restrictive Silencing Factor (NRSF) has been reported as a neuroprotective molecule in certain neurological disorders. Decreased expression levels of REST/NRSF in the nucleus can induce death-related gene expression, leading to neuronal death. Under physiological stress conditions, REST/NRSF over expression is known to activate neuronal survival in the brain. Alterations in REST/NRSF expression in the brain has been reported in stressed animal models and in the post-mortem brain of patients with depression. Here, we highlight the neuroprotective function of REST/NRSF and discuss dysregulation of REST/NRSF and neuronal damage during social stress and depression.

Mindfulness, Education, and Exercise for age-related cognitive decline: Study protocol, pilot study results, and description of the baseline sample

BACKGROUND/AIMS

Age-related cognitive decline is a pervasive problem in our aging population. To date, no pharmacological treatments to halt or reverse cognitive decline are available. Behavioral interventions, such as physical exercise and Mindfulness-Based Stress Reduction, may reduce or reverse cognitive decline, but rigorously designed randomized controlled trials are needed to test the efficacy of such interventions.

METHODS

Here, we describe the design of the Mindfulness, Education, and Exercise study, an 18-month randomized controlled trial that will assess the effect of two interventions-mindfulness training plus moderate-to-vigorous intensity exercise or moderate-to-vigorous intensity exercise alone-compared with a health education control group on cognitive function in older adults. An extensive battery of biobehavioral assessments will be used to understand the mechanisms of cognitive remediation, by using structural and resting state functional magnetic resonance imaging, insulin sensitivity, inflammation, and metabolic and behavioral assessments.

RESULTS

We provide the results from a preliminary study (n = 29) of non-randomized pilot participants who received both the exercise and Mindfulness-Based Stress Reduction interventions. We also provide details on the recruitment and baseline characteristics of the randomized controlled trial sample (n = 585).

CONCLUSION

When complete, the Mindfulness, Education, and Exercise study will inform the research community on the efficacy of these widely available interventions improve cognitive functioning in older adults.

Effects of Mindfulness-Based Interventions on Biomarkers and Low-Grade Inflammation in Patients with Psychiatric Disorders: A Meta-Analytic Review

Mindfulness-Based Interventions (MBIs) present positive effects on mental health in diverse populations. However, the detailed associations between MBIs and biomarkers in patients with psychiatric disorders remain poorly understood. The aim of this study was to examine the effects of MBIs on biomarkers in psychiatric illness used to summarise the effects of low-grade inflammation. A systematic review of PubMed, EMBASE, PsycINFO, and the Cochrane Library was conducted. Effect sizes (ESs) were determined by Hedges' g and the number needed to treat (NNT). Heterogeneity was evaluated. A total of 10 trials with 998 participants were included. MBIs showed significant improvements in the event-related potential amplitudes in attention-deficit hyperactivity disorder, the methylation of serotonin transporter genes in post-traumatic stress disorder, the salivary levels of interleukin 6 (IL-6) and tumour necrosis factor alpha (TNF-α) in depression, and the blood levels of adrenocorticotropic hormone (ACTH), IL-6, and TNF-α in generalised anxiety disorder. MBIs showed low but significant effects on health status related to biomarkers of low-grade inflammation (g = -0.21; 95% confidence interval (CI) -0.41 to -0.01; NNT = 8.47), with no heterogeneity (I² = 0; 95% CI 0 to 79). More trials are needed to establish the impact of MBIs on biomarkers in psychiatric illness.

Aryl Hydrocarbon Receptor in Post-Mortem Hippocampus and in Serum from Young, Elder, and Alzheimer's Patients

One of the characteristics of the cerebral aging process is the presence of chronic inflammation through glial cells, which is particularly significant in neurodegeneration. On the other hand, it has been demonstrated that the aryl hydrocarbon receptor (AHR) participates in the inflammatory response. Currently, evidence in animal models shows that the hallmarks of aging are associated with changes in the AHR levels. However, there is no information concerning the behavior and participation of AHR in the human aging brain or in Alzheimer’s disease (AD). We evaluated the expression of AHR in human hippocampal post-mortem tissue and its association with reactive astrocytes by immunohistochemistry. Besides this, we analyzed through ELISA the AHR levels in blood serum from young and elder participants, and from AD patients. The levels of AHR and glial fibrillar acid protein were higher in elder than in young post-mortem brain samples. AHR was localized mainly in the cytosol of astrocytes and displayed a pattern that resembles extracellular vesicles; this latter feature was more conspicuous in AD subjects. We found higher serum levels of AHR in AD patients than in the other participants. These results suggest that AHR participates in the aging process, and probably in the development of neurodegenerative diseases like AD.

REST and Neural Gene Network Dysregulation in iPSC Models of Alzheimer's Disease

The molecular basis of the earliest neuronal changes that lead to Alzheimer’s disease (AD) is unclear. Here, we analyze neural cells derived from sporadic AD (SAD), APOE4 gene-edited and control induced pluripotent stem cells (iPSCs). We observe major differences in iPSC-derived neural progenitor (NP) cells and neurons in gene networks related to neuronal differentiation, neurogenesis, and synaptic transmission. The iPSC-derived neural cells from SAD patients exhibit accelerated neural differentiation and reduced progenitor cell renewal. Moreover, a similar phenotype appears in NP cells and cerebral organoids derived from APOE4 iPSCs. Impaired function of the transcriptional repressor REST is strongly implicated in the altered transcriptome and differentiation state. SAD and APOE4 expression result in reduced REST nuclear translocation and chromatin binding, and disruption of the nuclear lamina. Thus, dysregulation of neural gene networks may set in motion the pathologic cascade that leads to AD.

Meyer et al. derive neural progenitors, neurons, and cerebral organoids from sporadic Alzheimer’s disease (SAD) and APOE4 gene-edited iPSCs. SAD and APOE4 expression alter the neural transcriptome and differentiation in part through loss of function of the transcriptional repressor REST. Thus, neural gene network dysregulation may lead to Alzheimer’s disease.

More than a Corepressor: The Role of CoREST Proteins in Neurodevelopment

The molecular mechanisms governing normal neurodevelopment are tightly regulated by the action of transcription factors. Repressor element 1 (RE1) silencing transcription factor (REST) is widely documented as a regulator of neurogenesis that acts by recruiting corepressor proteins and repressing neuronal gene expression in non-neuronal cells. The REST corepressor 1 (CoREST1), CoREST2, and CoREST3 are best described for their role as part of the REST complex. However, recent evidence has shown the proteins have the ability to repress expression of distinct target genes in a REST-independent manner. These findings indicate that each CoREST paralogue may have distinct and critical roles in regulating neurodevelopment and are more than simply “REST corepressors,” whereby they act as independent repressors orchestrating biological processes during neurodevelopment.

Biomarker potential of brain-secreted extracellular vesicles in blood in Alzheimer's disease

INTRODUCTION

Brain cells secrete extracellular microvesicles (EVs) that cross the blood-brain barrier. Involved in cell-to-cell communication, EVs contain surface markers and a biologically active cargo of molecules specific to their tissue (and cell) of origin, reflecting the tissue or cell's physiological state. Isolation of brain-secreted EVs (BEVs) from blood provides a minimally invasive way to sample components of brain tissue in Alzheimer's disease (AD), and is considered a form of "liquid biopsy."

METHODS

We performed a comprehensive review of the PubMed literature to assess the biomarker and therapeutic potential of blood-isolated BEVs in AD.

RESULTS

We summarize methods used for BEV isolation, validation, and novel biomarker discovery, as well as provide insights from 26 studies in humans on the biomarker potential in AD of four cell-specific BEVs isolated from blood: neuron-, neural precursor-, astrocyte-, and brain vasculature-derived BEVs. Of these, neuron-derived BEVs has been investigated on several fronts, and these include levels of amyloid-β and tau proteins, as well as synaptic proteins. In addition, we provide a synopsis of the current landscape of BEV-based evaluation/monitoring of AD therapeutics based on two published trials and a review of registered clinical trials.

DISCUSSION

Blood-isolated BEVs have emerged as a novel player in the study of AD, with enormous potential as a diagnostic, evaluation of therapeutics, and treatment tool. The literature has largely concentrated on neuron-derived BEVs in the blood in AD. Given the multifactorial pathophysiology of AD, additional studies, in neuron-derived and other brain cell-specific BEVs are warranted to establish BEVs as a robust blood-based biomarker of AD.

Stress and neurodegeneration

Neurodegenerative diseases are a great concern because of aging worldwide population. Despite substantial effort to advance our understanding of the etiology and potential treatment of neurodegeneration, there remains a paucity of information with respect to this complex disease process. Interestingly, stress has been implicated among the potential mechanisms implicated in neurodegenerative pathology. Given the increase in chronic stress in modern society, this premise warrants further investigation. The aim of this review is to evaluate the influence of stress on neurodegeneration, the effect of neurodegenerative diseases diagnosis on stress, and therapeutic strategies for neurodegenerative diseases with a special focus on stress reduction. Neurodegenerative disorders such as Alzheimer's, Parkinson's and Huntington's Disease showed an acceleration in disease progression and a worsening of symptoms under stress. Some therapies (e.g., yoga, meditation) focused on reducing stress showed beneficial effects against neurodegeneration. Nevertheless, more studies are necessary in order to completely understand the implications of stress in neurodegeneration and the usefulness of stress reduction in the treatment thereof.

News about the Role of the Transcription Factor REST in Neurons: From Physiology to Pathology

RE-1 silencing transcription factor (REST) (known also as NRSF) is a well-known transcription repressor whose strong decrease induces the distinction of neurons with respect to the other cells. Such distinction depends on the marked increased/decreased expression of specific genes, accompanied by parallel changes of the corresponding proteins. Many properties of REST had been identified in the past. Here we report those identified during the last 5 years. Among physiological discoveries are hundreds of genes governed directly/indirectly by REST, the mechanisms of its neuron/fibroblast conversions, and the cooperations with numerous distinct factors induced at the epigenetic level and essential for REST specific functions. New effects induced in neurons during brain diseases depend on the localization of REST, in the nucleus, where functions and toxicity occur, and in the cytoplasm. The effects of REST, including cell aggression or protection, are variable in neurodegenerative diseases in view of the distinct mechanisms of their pathology. Moreover, cooperations are among the mechanisms that govern the severity of brain cancers, glioblastomas, and medulloblastomas. Interestingly, the role in cancers is relevant also for therapeutic perspectives affecting the REST cooperations. In conclusion, part of the new REST knowledge in physiology and pathology appears promising for future developments in research and brain diseases.

The interaction between RE1-silencing transcription factor (REST) and heat shock protein 90 as new therapeutic target against Huntington's disease

The wild type huntingtin protein (Htt), supports the production of brain-derived neurotrophic factor (BDNF), a survival factor for striatal neurons, through cytoplasmic sequestering of RE-1silencing transcription factor (REST). In Huntington´s Disease an inherited degenerative disease, caused by a CAG expansion in the 5´coding region of the gene, the mutant huntingtin protein (mHtt), causes that REST enters pathologically into the nucleus of cells, resulting in the repression of neuronal genes including BDNF, resulting in the progressive neuronal death. It has been reported that Htt associates with Hsp90 and this interaction is involved in regulation of huntingtin aggregation. Discovering mechanisms to reduce the cellular levels of mutant huntingtin and REST provide promising strategies for treating Huntington disease. Here, we use the yeast two-hybrid system to show that N-terminus or REST interacts with the heat shock protein 90 (Hsp90) and identifies REST as an Hsp90 Client Protein. To assess the effects of Hsp90 we used antisense oligonucleotide, and evaluated the levels mHtt and REST levels. Our results show that direct knockdown of endogenous Hsp90 significantly reduces the levels of REST and mutant Huntingtin, decreased the percentage of cells with mHtt in nucleus and rescued cells from mHtt-induced cellular cytotoxicity. Additionally Hsp90–specific inhibitors geldanamicyn and PUH71 dramatically reduced mHtt and REST levels, thereby providing neuroprotective activity. Our data show that Hsp90 is necessary to maintain the levels of REST and mHtt, which suggests that the interactions between Hsp90-REST and Hsp90-Huntingtin could be potential therapeutic targets in Huntington's disease.

Supervised pathway analysis of blood gene expression profiles in Alzheimer's disease

Early identification and treatment of Alzheimer's disease (AD) is hampered by the lack of easily accessible biomarkers. Currently available fluid biomarkers of AD provide indications of the disease stage; however, these are measured in the cerebrospinal fluid, requiring invasive procedures, which are not applicable at the population level. Thus, gene expression profiling of blood provides a viable alternative as a way to screen individuals at risk of AD. Previous studies have shown that despite the limited permeability of the blood-brain barriers, expression profiles of blood genes can be used for the diagnosis and prognosis of several brain disorders. Here, we propose a new approach to pathway analysis of blood gene expression profiles to classify healthy (control [CTL]), mildly cognitively impaired (mild cognitive impairment [MCI]; preclinical stage of AD), and AD subjects. In the pathway analysis, gene expression data are mapped to pathway scores according to a predefined gene set instead of considering each gene separately. The robustness of the analysis enables detection of weak differences between groups owing to the inherent dimension reduction. Our proposed method for pathway analysis takes advantage of linear discriminant analysis for identifying a linear combination of features best separating groups of subjects within each gene set. The gene expression data were retrieved from Gene Expression Omnibus (batch 1: GSE63060; batch 2: GSE63061). Predefined gene sets for pathway analysis were obtained from the Broad Institute Collection of Curated Pathways. The method achieved a 10-fold cross-validated area under receiver operating characteristic curve of 0.84 for classification of AD versus CTL and 0.80 for classification of mild cognitive impairment versus CTL. These results reveal the good potential of blood-based biomarkers for assisting early diagnosis and disease monitoring of AD.

REST/NRSF transcription factor is overexpressed in hippocampus of patients with drug-resistant mesial temporal lobe epilepsy

The Repressor Element-1 Silencing Transcription factor or Neuron-Restrictive Silencer Factor (REST/NRSF) is a zinc finger repressor transcription factor of the Kruppel family. Several studies in experimental models have shown that overexpression of REST/NRSF occurs after the induction of seizures. In the present study, the expression of REST/NRSF (messenger ribonucleic acid (mRNA) and protein) was evaluated in the hippocampus of 28 patients with drug-resistant mesial temporal lobe epilepsy (MTLE) and their correlation with clinical variables and comorbid anxiety and depression. The REST/NRSF protein expression was augmented in an age-dependent manner in the hippocampus of autopsied subjects. However, this condition was not observed in patients with MTLE, in whom overexpression of this transcription factor occurred at both the mRNA and protein levels. The correlations with clinical variables showed that the frequency of epileptic seizures was proportional to the protein expression of REST/NRSF. The results revealed that the overexpression of REST/NRSF was more evident in patients with MTLE without anxiety and depression. Our data indicate that the expression of REST/NRSF is modified in patients with MTLE. This condition has implications in the pathophysiology of this disorder, making it a potential candidate for the optimization of clinical treatments.

The Effects of Yoga on Patients with Mild Cognitive Impairment and Dementia: A Scoping Review

Yoga is an ancient mind body practice. Although yoga has been used as a complementary health approach for enhancing wellness and addressing a variety of health issues, little is known about the impact of yoga on cognitive functioning in adults with mild cognitive impairment (MCI) and dementia. We conducted a literature review to examine the impact of yoga on persons with MCI and dementia. Eight studies were identified that reported on yoga as either the primary intervention or one component of a multi-component intervention in samples of persons with MCI or dementia. Results suggest that yoga may have beneficial effects on cognitive functioning, particularly on attention and verbal memory. Further, yoga may affect cognitive functioning through improved sleep, mood, and neural connectivity. There are a number of limitations of the existing studies, including a lack of intervention details, as well as variability in the frequency/duration and components of the yoga interventions. A further complicating issue is the role of various underlying etiologies of cognitive impairment. Despite these limitations, providers may consider recommending yoga to persons with MCI or dementia as a safe and potentially beneficial complementary health approach.

The SCD-Well randomized controlled trial: Effects of a mindfulness-based intervention versus health education on mental health in patients with subjective cognitive decline (SCD)

Introduction

Subjectively experienced cognitive decline in older adults is an indicator of increased risk for dementia and is also associated with increased levels of anxiety symptoms. As anxiety is itself emerging as a risk factor for cognitive decline and dementia, the primary question of the present study is whether an 8-week mindfulness-based intervention can significantly reduce anxiety symptoms in patients with subjective cognitive decline (SCD). The secondary questions pertain to whether such changes extend to other domains of psychological, social, and biological functioning (including cognition, self-regulation, lifestyle, well-being and quality of life, sleep, and selected blood-based biomarkers) associated with mental health, older age, and risk for dementia.

Methods

SCD-Well is a multicenter, observer-blinded, randomized, controlled, superiority trial, which is part of the Horizon 2020 European Union-funded “Medit-Ageing” project. SCD-Well compares an 8-week mindfulness- and compassion-based intervention specifically adapted for older adults with SCD with a validated 8-week health education program. Participants were recruited from memory clinics in four European sites (Cologne, Germany; London, United Kingdom; Barcelona, Spain; and Lyon, France) and randomized with a 1:1 allocation, stratified by site.

Results

The primary outcome, change in anxiety symptoms, and secondary outcomes reflecting psychological, cognitive, social, and biological functioning are assessed at baseline, postintervention, and 4 months after the end of the intervention.

Discussion

The study will provide evidence on whether a mindfulness-based intervention can effect changes in anxiety and other risk factors for cognitive decline and dementia in older adults with SCD and will inform the establishment of intervention strategies targeted at improving mental health in older adults.

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Mindfulness may benefit older adults with subjective cognitive decline (SCD).

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SCD-Well compares an 8-week mindfulness intervention to a health education course.

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Patients with SCD were recruited from memory clinics in four countries.

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Outcomes include anxiety symptoms, psychosocial, cognitive, and biological function.

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Results will inform future prevention studies and strategies in SCD.

Effects of Meditation and Music-Listening on Blood Biomarkers of Cellular Aging and Alzheimer's Disease in Adults with Subjective Cognitive Decline: An Exploratory Randomized Clinical Trial

BACKGROUND

Telomere length (TL), telomerase activity (TA), and plasma amyloid-β (Aβ) levels have emerged as possible predictors of cognitive decline and dementia.

OBJECTIVE

To assess the: 1) effects of two 12-week relaxation programs on TL, TA, and Aβ levels in adults with subjective cognitive decline; and 2) relationship of biomarker changes to those in cognitive function, psychosocial status, and quality of life (QOL).

METHODS

Participants were randomized to a 12-week Kirtan Kriya meditation (KK) or music listening (ML) program and asked to practice 12 minutes/day. Plasma Aβ(38/40/42) and peripheral blood mononuclear cell TL and TA were measured at baseline and 3 months. Cognition, stress, sleep, mood, and QOL were assessed at baseline, 3 months, and 6 months.

RESULTS

Baseline blood samples were available for 53 participants (25 KK, 28 ML). The KK group showed significantly greater increases in Aβ40 than the ML group. TA rose in both groups, although increases were significant only among those with higher practice adherence and lower baseline TA. Changes in both TL and TA varied by their baseline values, with greater increases among participants with values ≤50th percentile (ps-interaction <0.006). Both groups improved in cognitive and psychosocial status (ps ≤0.05), with improvements in stress, mood, and QOL greater in the KK group. Rising Aβ levels were correlated with gains in cognitive function, mood, sleep, and QOL at both 3 and 6 months, associations that were particularly pronounced in the KK group. Increases in TL and TA were also correlated with improvements in certain cognitive and psychosocial measures.

CONCLUSION

Practice of simple mind-body therapies may alter plasma Aβ levels, TL, and TA. Biomarker increases were associated with improvements in cognitive function, sleep, mood, and QOL, suggesting potential functional relationships.

Mind-Body Therapies in Individuals With Dementia: An Integrative Review

Mind-body therapies frequently derive from Eastern philosophies and are becoming increasingly popular. These therapies, such as meditation, yoga, tai chi, qigong, biofield therapies, and guided imagery, have many reported benefits for improving symptoms and physiological measures associated with various chronic diseases. However, clinical research data concerning the effectiveness of these practices in individuals with dementia have not been evaluated using a synthesis approach. Thus, an integrative review was conducted to evaluate studies examining the efficacy of mind-body therapies as supportive care modalities for management of symptoms experienced by individuals with dementia. Findings from the studies reviewed support the clinical efficacy of mind-body practices in improving behavioral and psychological symptoms exhibited by individuals with dementia. [Res Gerontol Nurs. 2017; 10(6):288-296.].