The future of Alzheimer's disease: the next 10 years

FOXO1 locus and acetylcholinesterase inhibitors in elderly patients with Alzheimer's disease

Objective

Acetylcholinesterase inhibitors (AChEIs) may reduce the oxidative stress in brain of Alzheimer’s disease (AD) patients. Forkhead box O1 (FOXO1) protein has been reported as the link between oxidative stress and AD. We evaluated a potential association between FOXO1 gene locus and the response to AChEI treatment in patients with sporadic AD.

Methods

In this prospective study, 109 Caucasian AD patients were treated with standard doses of donepezil, galantamine, or rivastigmine for 6 months. Functional and cognitive status were evaluated at baseline and after treatment. Response to therapy was defined according to the National Institute for Health and Clinical Excellence criteria. Genotype analyses, including the APOE polymorphism, were made in blinded fashion.

Results

A significantly higher frequency of FOXO1 rs7981045 G/G genotype was observed in nonresponders compared with responders (17.14% versus 2.70%, P=0.010). Age, sex, and APOE-adjusted logistic regression analysis confirmed that patients with the G/G genotype had a significantly higher risk of poor response to AChEI treatment (odds ratio =10.310; 95% confidence interval, 1.510–70.362). Haplotype analysis revealed significant differences in haplotype frequency distribution between these groups.

Conclusion

FOXO1 may influence the clinical response to AChEIs in AD patients.

NILVAD protocol: a European multicentre double-blind placebo-controlled trial of nilvadipine in mild-to-moderate Alzheimer's disease

INTRODUCTION

This study is a European multicentre, randomised, double-blind, placebo-controlled trial investigating the efficacy and safety of nilvadipine as a disease course modifying treatment for mild-to-moderate Alzheimer's disease (AD) in a phase III study that will run for a period of 82 weeks with a treatment period of 78 weeks.

METHODS AND ANALYSIS

Adult patients, males and females over 50 years with mild-to-moderate AD as defined by the National Institute of Neurological and Communicative Disorders and Stroke/Alzheimer's disease and Related Disorders Association (NINCDS-ADRDA) criteria, will be included in the study. It aims to recruit a total of 500 patients with AD; 250 in the nilvadipine group and 250 in the placebo group. Participants will be randomised to receive nilvadipine, an 8 mg overencapsulated, sustained release capsule, or a matching overencapsulated placebo (sugar pill) for a period of 78 weeks of treatment. The primary efficacy outcome measure in this study is the change in cognitive function as assessed by the Alzheimer's disease Assessment Scale (ADAS-Cog 12) from baseline to the end of treatment duration (78 weeks). There are two key secondary outcome measures, the Clinical Dementia Rating Scale Sum of Boxes (CDR-sb) and the Disability Assessment for Dementia (DAD). If a statistically significant effect is seen in the primary outcome, CDR-sb will be considered to be a coprimary end point and only the DAD will contribute to the secondary outcome analysis.

ETHICS AND DISSEMINATION

The study and all subsequent amendments have received ethical approval within each participating country according to national regulations. Each participant will provide written consent to participate in the study. All participants will remain anonymised throughout and the results of the study will be published in an international peer-reviewed journal.

TRIAL REGISTRATION NUMBER

EUDRACT Reference Number: 2012-002764-27.

Is Alzheimer's disease related to metabolic syndrome? A Wnt signaling conundrum

Alzheimer's disease (AD) is the most common cause of dementia, affecting more than 36 million people worldwide. AD is characterized by a progressive loss of cognitive functions. For years, it has been thought that age is the main risk factor for AD. Recent studies suggest that life style factors, including nutritional behaviors, play a critical role in the onset of dementia. Evidence about the relationship between nutritional behavior and AD includes the role of conditions such as obesity, hypertension, dyslipidemia and elevated glucose levels. The coexistence of some of these cardio-metabolic risk factors is generally known as metabolic syndrome (MS). Some clinical studies support the role of MS in the onset of AD. However, the cross-talk between the molecular signaling implicated in these disorders is unknown. In the present review, we focus on the molecular correlates that support the relationship between MS and the onset of AD. We also discuss relevant issues such as the role of leptin, insulin and renin-angiotensin signaling in the brain and the possible role of Wnt signaling in both MS and AD. We discuss the evidence supporting the use of ob/ob mice, high-fructose diets, aortic coarctation-induced hypertension and Octodon degus, which spontaneously develops β-amyloid deposits and metabolic derangements, as suitable animal models to address the relationships between MS and AD. Finally, we examine emergent data supporting the role of Wnt signaling in the modulation of AD and MS, implicating this pathway as a therapeutic target in both conditions.

The effects of health education on knowledge about Alzheimer's disease and health-promoting behaviours of older Chinese adults in a nursing home: A pilot study

This pilot study tested the effects of health education on knowledge of Alzheimer's disease (AD) and health-promotion lifestyles among older Chinese adults residing in a nursing home in Wuhan. A convenience sample of 35 elders without AD was recruited from a nursing home in Wuhan and provided with a 5 week health education intervention. Participants had little knowledge about AD and had an intermediate level of health promotion. After receiving the intervention, there were significant increases in scores on AD knowledge (F = 29.69, df = 1.23, P < 0.01) and health-promotion lifestyle (F = 4.39, df = 2, P < 0.05). These results suggest that the intervention on AD knowledge and health promotion was effective for elders in this study. Nurses should therefore provide education for elders in nursing homes to improve their AD knowledge and health-promotion lifestyles, and to prevent or ameliorate AD.

Cu(II) and dopamine bind to α-synuclein and cause large conformational changes

α-Synuclein (AS) is an intrinsically disordered protein that can misfold and aggregate to form Lewy bodies in dopaminergic neurons, a classic hallmark of Parkinson's disease. The binding of Cu(II) and dopamine to AS was evaluated by nanopore analysis with α-hemolysin. In the absence of Cu(II), wild-type AS (1 μM) readily translocated through the pore with a blockade current of--85 pA, but mostly bumping events were observed in the presence of 25 μM Cu(II). A binding site in the N-terminus was confirmed, because Cu(II) had no effect on the event profile of a peptide consisting of the C-terminal 96-140 residues. In the presence of dopamine (25 μM), the translocation events at--85 pA shifted to--80 pA, which also represents translocation events, because the event time decreases with increasing voltage. Events at--80 pA were also observed for the mutant A30P AS in the presence of dopamine. Event profiles for an N-terminal 1-60-residue peptide and a C-terminal 96-140-residue peptide were both altered in the presence of 25 μM dopamine. In contrast, dopamine had little effect on the CD spectrum of AS, and a single binding site with a Ka of 3.5 × 10(3) m(-1) was estimated by isothermal titration calorimetry. Thus, dopamine can interact with both the N-terminus and the C-terminus. Two-dimensional NMR spectroscopy of AS in the presence of dopamine showed that there were significant changes in the spectra in all regions of the protein. According to these findings, a model is presented in which dopamine induces folding between the N-terminus and C-terminus of AS. Partially folding conformations such as this may represent important intermediates in the misfolding of AS that leads to fibrillization.

Analysis of neural dynamics in mild cognitive impairment and Alzheimer's disease using wavelet turbulence

OBJECTIVE

Current diagnostic guidelines encourage further research for the development of novel Alzheimer's disease (AD) biomarkers, especially in its prodromal form (i.e. mild cognitive impairment, MCI). Magnetoencephalography (MEG) can provide essential information about AD brain dynamics; however, only a few studies have addressed the characterization of MEG in incipient AD.

APPROACH

We analyzed MEG rhythms from 36 AD patients, 18 MCI subjects and 27 controls, introducing a new wavelet-based parameter to quantify their dynamical properties: the wavelet turbulence.

MAIN RESULTS

Our results suggest that AD progression elicits statistically significant regional-dependent patterns of abnormalities in the neural activity (p < 0.05), including a progressive loss of irregularity, variability, symmetry and Gaussianity. Furthermore, the highest accuracies to discriminate AD and MCI subjects from controls were 79.4% and 68.9%, whereas, in the three-class setting, the accuracy reached 67.9%.

SIGNIFICANCE

Our findings provide an original description of several dynamical properties of neural activity in early AD and offer preliminary evidence that the proposed methodology is a promising tool for assessing brain changes at different stages of dementia.

Dementia care management: going new ways in ambulant dementia care within a GP-based randomized controlled intervention trial

BACKGROUND

Increasing prevalence of dementia is a major challenge for the German healthcare system. The study DelpHi-MV ("Dementia: life- and person-centered help in Mecklenburg-Western Pomerania") aims to implement and evaluate an innovative subsidiary support system for persons with dementia (PwDs) living at home and their caregivers.

METHODS

DelpHi-MV is a GP-based cluster randomized controlled intervention trial. DelpHi-Intervention aims to provide "optimum care" by integrating multi-professional and multimodal strategies to individualize and optimize treatment of dementia within the framework of the established healthcare and social service system. The intervention is conducted by Dementia Care Managers (DCMs)--nurses with dementia-specific training--at the people's homes. Based on German guidelines for evidence-based diagnoses and treatment of dementia, a comprehensive set of 95 interventio--modules--the "DelpHi-Standard"--was defined. Each module consists of predefined trigger condition(s), a subsequent intervention task, as well as at least one criterion for its completion. The intervention begins with a comprehensive assessment of the care situation, needs, and resources. The DCM develops and implements an intervention plan tailored to the individual conditions in close cooperation with the GP. EXPECTED RESULTS AND CONCLUSIONS: We expect statistically significant differences between control and intervention group in primary outcomes (quality of life, behavioral and psychological symptoms of dementia, pharmacotherapy, caregiver burden). Results can provide evidence for the effectiveness and efficacy of dementia care management according to the "Delphi-Standard"--prerequisites for implementing this concept into routine healthcare.

Electroacupuncture decreases cognitive impairment and promotes neurogenesis in the APP/PS1 transgenic mice

BACKGROUND

Alzheimer's disease (AD) is a severe neurodegenerative disease for which there is currently no effective treatment. The purpose of this study was to investigate whether repeated electroacupuncture (EA) stimulation would improve cognitive function and the pathological features of AD in amyloid precursor protein (APP)/presenilin 1 (PS1) double transgenic mice.

METHODS

Cognitive function of APP/PS1 double transgenic mice was assessed using the Morris water maze test before and after EA treatment. Levels of amyloid β-peptide (Aβ) deposits in the hippocampus and cortex were evaluated by immunofluorescence, western blot and enzyme-linked immunosorbent assay. Expression of brain-derived neurotrophic factor (BDNF) was also examined by immunofluorescence and western blot. The neurogenesis was labeled by the DNA marker bromodeoxyuridine.

RESULTS

EA stimulation significantly ameliorated the learning and memory deficits of AD mice by shortening escape latency and increasing the time spent in the target zone during the probe test. Additionally, decreased Aβ deposits and increased BDNF expression and neurogenesis in the hippocampus and cortex of EA-treated AD mice were detected. The same change was detected in wild-type mice after EA treatment compared with wild-type mice without EA treatment.

CONCLUSIONS

Repeated EA stimulation may improve cognitive function, attenuate Aβ deposits, up-regulate the expression of BDNF and promote neurogenesis in the APP/PS1 double transgenic mice. This suggests that EA may be a promising treatment for AD.

Total body 100-mGy X-irradiation does not induce Alzheimer's disease-like pathogenesis or memory impairment in mice

The cause and progression of Alzheimer's disease (AD) are poorly understood. Possible cognitive and behavioral consequences induced by low-dose radiation are important because humans are exposed to ionizing radiation from various sources. Early transcriptional response in murine brain to low-dose X-rays (100 mGy) has been reported, suggesting alterations of molecular networks and pathways associated with cognitive functions, advanced aging and AD. To investigate acute and late transcriptional, pathological and cognitive consequences of low-dose radiation, we applied an acute dose of 100-mGy total body irradiation (TBI) with X-rays to C57BL/6J Jms mice. We collected hippocampi and analyzed expression of 84 AD-related genes. Mouse learning ability and memory were assessed with the Morris water maze test. We performed in vivo PET scans with (11)C-PIB, a radiolabeled ligand for amyloid imaging, to detect fibrillary amyloid beta peptide (Aβ) accumulation, and examined characteristic AD pathologies with immunohistochemical staining of amyloid precursor protein (APP), Aβ, tau and phosphorylated tau (p-tau). mRNA studies showed significant downregulation of only two of 84 AD-related genes, Apbb1 and Lrp1, at 4 h after irradiation, and of only one gene, Il1α, at 1 year after irradiation. Spatial learning ability and memory were not significantly affected at 1 or 2 years after irradiation. No induction of amyloid fibrillogenesis or changes in APP, Aβ, tau, or p-tau expression was detected at 4 months or 2 years after irradiation. TBI induced early or late transcriptional alteration in only a few AD-related genes but did not significantly affect spatial learning, memory or AD-like pathological change in mice.

Perspective on future role of biological markers in clinical therapy trials of Alzheimer's disease: a long-range point of view beyond 2020

Recent advances in understanding the molecular mechanisms underlying various paths toward the pathogenesis of Alzheimer's disease (AD) has begun to provide new insight for interventions to modify disease progression. The evolving knowledge gained from multidisciplinary basic research has begun to identify new concepts for treatments and distinct classes of therapeutic targets; as well as putative disease-modifying compounds that are now being tested in clinical trials. There is a mounting consensus that such disease modifying compounds and/or interventions are more likely to be effectively administered as early as possible in the cascade of pathogenic processes preceding and underlying the clinical expression of AD. The budding sentiment is that "treatments" need to be applied before various molecular mechanisms converge into an irreversible pathway leading to morphological, metabolic and functional alterations that characterize the pathophysiology of AD. In light of this, biological indicators of pathophysiological mechanisms are desired to chart and detect AD throughout the asymptomatic early molecular stages into the prodromal and early dementia phase. A major conceptual development in the clinical AD research field was the recent proposal of new diagnostic criteria, which specifically incorporate the use of biomarkers as defining criteria for preclinical stages of AD. This paradigm shift in AD definition, conceptualization, operationalization, detection and diagnosis represents novel fundamental opportunities for the modification of interventional trial designs. This perspective summarizes not only present knowledge regarding biological markers but also unresolved questions on the status of surrogate indicators for detection of the disease in asymptomatic people and diagnosis of AD.

Antidepressants for neuro-regeneration: from depression to Alzheimer's disease

Recently identified new potential functions of antidepressants in the treatment of neurodegenerative will be introduced. Antidepressants are reported to regulate stem cell fate to regenerate neurons in the adult hippocampus and are effective in reducing toxic amyloid peptides and are known to increase neurotrophic factor such as brain-derived neurotrophic factor. Clinical trial data support that antidepressants have potential to treat Alzheimer's disease.

Perceived unmet needs of informal caregivers of people with dementia in Singapore

BACKGROUND

This study aimed to explore the experiences and challenges of informal caregivers in Singapore with the intent of identifying the multi-dimensional unmet needs from their perspective and generating caregivers' needs checklist based on the findings.

METHODS

Informal caregivers were relatives of people with dementia and were responsible for organizing care and providing regular physical and/or financial support. Using a qualitative research design, informal caregivers' experiences were explored. A total of ten focus group discussions and 12 semi-structured interviews were conducted with adult caregivers. Caregivers' perceived unmet needs were identified using thematic analysis. Findings from the qualitative study were combined with inputs from professionals to create a checklist of caregivers' needs for dementia.

RESULTS

The average age of the participants was 52.9 years; the majority of the participants were of Chinese ethnicity (50%), followed by Indian (23%), Malay (22%), and other (3%) ethnic groups. Informal caregivers perceived four categories of unmet needs: (i) emotional and social support, (ii) information, (iii) financial support, and (iv) accessible and appropriate facilities. Caregivers strongly expressed the need for emotional support to overcome the psychological and physical burden of care. Challenges with obtaining adequate information, access to services, and financial barriers were discussed. Based on these findings and expert panel discussions, a checklist of 26 items representing their unmet needs was designed.

CONCLUSIONS

Informal caregivers face several challenges while caring for their relative with dementia and hence there is a clear demand to address their unmet needs for information, services, respite, and emotional and financial support.

Oxidative stress in aging--matters of the heart and mind

Oxidative damage is considered to be the primary cause of several aging associated disease pathologies. Cumulative oxidative damage tends to be pervasive among cellular macromolecules, impacting proteins, lipids, RNA and DNA of cells. At a systemic level, events subsequent to oxidative damage induce an inflammatory response to sites of oxidative damage, often contributing to additional oxidative stress. At a cellular level, oxidative damage to mitochondria results in acidification of the cytoplasm and release of cytochrome c, causing apoptosis. This review summarizes findings in the literature on oxidative stress and consequent damage on cells and tissues of the cardiovascular system and the central nervous system, with a focus on aging-related diseases that have well-documented evidence of oxidative damage in initiation and/or progression of the disease. The current understanding of the cellular mechanisms with a focus on macromolecular damage, impacted cellular pathways and gross morphological changes associated with oxidative damage is also reviewed. Additionally, the impact of calorific restriction with its profound impact on cardiovascular and neuronal aging is addressed.

Medication adherence survey of drugs useful in prevention of dementia of Alzheimer's type among Indian patients

BACKGROUND

Good medication adherence is the cornerstone of therapeutic success. Alzheimer's disease (AD) is the most common type of dementia and most patients are old and on multiple drugs, and good compliance therefore is even more important in this population. Dementia of Alzheimer's type (DAT) at present is yet to find a cure. Anticholinesterases and N-methyl-D-aspartate blockers are specific anti-AD therapies available. Hypertension, diabetes, and dyslipidemia can contribute to cognitive worsening. Keeping hypertension, diabetes, and dyslipidemia in control can therefore possibly prevent further cognitive decline.

METHODS

Patients with subjective memory complaints (n = 75) were chosen randomly. Upon thorough neurological diagnostic work up for dementia, those with mild cognitive impairment/questionable dementia (Clinical Dementia Rating = 0.5) or those with AD were recruited in this study (n = 67). Those with hypertension, diabetes, and deranged lipid profile were further interviewed if they were able to take medicines regularly or not. An attempt was made to know causes of non-compliance.

RESULTS

Forty-one percent of patients were not taking the drugs that have potential to prevent cardiovascular complications or ability to slow down cognitive decline in AD on regular basis. The lack of awareness, ignorance, medicines being "too expensive," and the pressure of taking medicines regularly were cited as the reasons for non-compliance. Being illiterate and having low education contributed majorly to poor compliance in this study.

CONCLUSION

Compliance to drugs that have potential or real ability to slow down cognitive decline is low in elderly people with DAT.

CSF Aβ1-42 combined with neuroimaging biomarkers in the early detection, diagnosis and prediction of Alzheimer's disease

The development of validated, qualified, and standardized biomarkers for Alzheimer's disease (AD) that allow for an early presymptomatic diagnosis and discrimination (classification) from other types of dementia and neurodegenerative diseases is warranted to accelerate the successful development of novel disease-modifying therapies. Here, we focus on the value of the 42-residue-long amyloid β isoform (Aβ1-42) peptide in the cerebrospinal fluid as the core, feasible neurobiochemical marker for the amyloidogenic mechanisms in early-onset familial and late-onset sporadic AD. We discuss the role and use of Aβ1-42 in combination with evolving neuroimaging biomarkers in AD detection and diagnosis. Multimodal neuroimaging techniques, directly providing structural-functional-metabolic aspects of brain pathophysiology, are supportive to predict and monitor the progression of the disease. Advances in multimodal neuroimaging provide new insights into brain organization and enable the detection of specific proteins and/or protein aggregates associated with AD. The combination of biomarkers from different methodologies is believed to be of incrementally added risk-value to accurately identify asymptomatic and prodromal individuals who will likely progress to dementia and represent rational biomarker candidates for preventive and symptomatic pharmacological intervention trials.

Neuropsychiatry: where are we and where do we go from here?

Introduction:

Neuropsychiatry has generally been regarded as a hybrid discipline that lies in the borderland between the disciplines of psychiatry and neurology. There is much debate on its current and future identity and status as a discipline.

Materials and Methods:

Taking a historical perspective, the future of neuropsychiatry is placed within the context of recent developments in clinical neuroscience.

Results:

The authors argue that with the maturation of the discipline, it must define its own identity that is not dependent entirely upon the parent disciplines. The requirements for this are the claiming of neuropsychiatric territory, a strong training agenda, an emphasis on treatments that are uniquely neuropsychiatric, and a bold embrace of new developments in clinical neuroscience.

Conclusion:

The exponential growth in neuroscientific knowledge places neuropsychiatry in an excellent position to carve out a strong identity. It is imperative that the leaders of the discipline seize the moment.

Liposomes functionalized to overcome the blood-brain barrier and to target amyloid-β peptide: the chemical design affects the permeability across an in vitro model

Purpose

We investigated the ability of amyloid-β-targeting liposomes, decorated with an anti-transferrin receptor antibody, to cross the blood–brain barrier (BBB), comparing two antibody ligation techniques.

Methods

Fluorescent or radiolabeled liposomes composed of sphingomyelin/cholesterol and containing phosphatidic acid, known to bind amyloid-β, were further functionalized with the anti-transferrin receptor antibody RI7217. Two different techniques were used to attach RI7217 to the liposomes surface: biotin/streptavidin linkage or thiol–maleimide covalent ligation. Surface plasmon resonance (SPR) and immunoblotting were employed to assess the nanoparticles’ binding performances. Confocal microscopy and radiochemical techniques were used for uptake and permeability studies on an in vitro BBB model made of human brain capillary endothelial cells hCMEC/D3.

Results

Immunoblotting experiments showed that RI7217-functionalized liposomes bind to transferrin receptor independently of the procedure employed to ligate their surface with the antibody, while SPR experiments showed a slightly higher affinity for covalently functionalized nanoliposomes. The functionalization with RI7217 did not affect the liposomes’ affinity for amyloid-β. The functionalization of liposomes with RI7217, independently of the ligation procedure, gave higher values of uptake and permeability across the barrier model in comparison to the nondecorated ones, without cell monolayer alterations. Of note, the best performing particles were those covalently coupled with the antibody. The ratios of the two radiolabeled lipids (³H-sphingomyelin and ¹⁴C-phosphatidic acid) present in the liposome bilayer were found to be similar in the apical and in the basolateral compartments of the barrier model, suggesting that liposomes were transported intact across the cell monolayer. Confocal experiments showed no co-localization of RI7217-liposomes with early/late endosomes or early lysosomes.

Conclusion

Our results suggest that RI7217 promotes the in vitro barrier crossing of liposomes containing phosphatidic acid, targeting the Alzheimer’s disease amyloid-β peptide. Moreover, for the first time, we prove herein the superior efficiency of covalent coupling of RI7217 versus biotin/streptavidin ligation to facilitate liposomes in overcoming the BBB in vitro.

Positron emission tomography imaging of fibrillar parenchymal and vascular amyloid-β in TgCRND8 mice

Few quantitative diagnostic and monitoring, tools are available to clinicians treating patients with Alzheimer's disease. Further, many of the promising quantitative imaging tools under development lack clear specificity toward different types of Amyloid-β (Aβ) pathology such as vascular or oligomeric species. Antibodies offer an opportunity to image specific types of Aβ pathology because of their excellent specificity. In this study, we developed a method to translate a panel of anti-Aβ antibodies, which show excellent histological performance, into live animal imaging contrast agents. In the TgCRND8 mouse model of Alzheimer's disease, we tested two antibodies, M64 and M116, that target parenchyma aggregated Aβ plaques and one antibody, M31, that targets vascular Aβ. All three antibodies were administered intravenously after labeling with both poly(ethylene glycol) to enhance circulation and (64)Cu to allow detection via positron emission tomography (PET) imaging. We were clearly able to differentiate TgCRND8 mice from wild type controls by PET imaging using either M116, the anti-Aβ antibody targeting parenchymal Aβ or M31, the antivascular Aβ antibody. To confirm the validity of the noninvasive imaging of specific Aβ pathology, brains were examined after imaging and showed clear evidence of binding to Aβ plaques.

Anti-amyloid-β-mediated positron emission tomography imaging in Alzheimer's disease mouse brains

Antibody-mediated imaging of amyloid β (Aβ) in Alzheimer's disease (AD) offers a promising strategy to detect and monitor specific Aβ species, such as oligomers, that have important pathological and therapeutic relevance. The major current limitation of antibodies as a diagnostic and imaging device is poor blood-brain-barrier permeability. A classical anti-Aβ antibody, 6E10, is modified with 10 kDa polyethylene glycol (PEG) and a positron emitting isotope, Copper-64 (t_½ = 12.7 h), and intravenously delivered to the TgCRND8 mouse model of Alzheimer's disease. Modification of 6E10 with PEG (6E10-PEG) increases accumulation of 6E10 in brain tissue in both TgCRND8 and wild type control animals. 6E10-PEG differentiates TgCRND8 animals from wild type controls using positron emission tomography (PET) and provides a framework for using antibodies to detect pathology using non-invasive medical imaging techniques.

Recognition performance differentiates between elderly patients in the long term course of secondary progressive multiple sclerosis and amnestic mild cognitive impairment

Background:

Cognitive impairment is a common symptom of multiple sclerosis (MS), but little is known about cognitive decline in patients in the long-term course of progressive MS. Because advancing age is the most significant risk factor for Alzheimer’s Disease (AD), AD-related pathology must be considered in elderly patients with MS. Amnestic mild cognitive impairment (aMCI) represents the prodromal phase of AD with subjects showing memory impairment that does not improve with recognition testing.

Objective:

We sought to identify disease-dependent deterioration patterns by comparing elderly patients with secondary progressive MS (SPMS) and with aMCI using the Consortium to Establish a Registry for Alzheimer’s Disease test battery.

Methods:

This study included 120 age-, education- and gender-matched participants, including healthy controls ( n=40), SPMS patients ( n=40), and aMCI patients ( n=40).

Results:

Episodic memory deficits appeared in the long-term course of SPMS. Deficits were associated with deterioration of executive function, but not impairment of memory storage as recognition was preserved in SPMS in contrast to the patients with aMCI.

Conclusion:

Through neuropsychological testing, MS-related episodic memory impairment due to deteriorated executive function can be distinguished from AD-related encoding and storage deficits. Hence, neuropsychological testing may help to identify AD-related pathology in SPMS patients.

Development of biomarkers to chart all Alzheimer's disease stages: the royal road to cutting the therapeutic Gordian Knot

The aim of this perspective article is to stimulate radical shifts in thinking and foster further discussion on the effective discovery, development, validation, and qualification process of biological markers derived from all available technical modalities that meet the complex conceptual and pathophysiological challenges across all stages of the complex, nonlinear, dynamic, and chronically progressive sporadic Alzheimer's disease (AD). This perspective evaluates the current state of the science regarding a broad spectrum of hypothesis-driven and exploratory technologies and "markers" as candidates for all required biomarker functions, in particular, surrogate indicators of adaptive to maladaptive and compensatory to decompensatory, reversible to irreversible brain "systems failure." We stress the future importance of the systems biology (SB) paradigm (next to the neural network paradigm) for substantial progress in AD research. SB represents an integrated and deeper investigation of interacting biomolecules within cells and organisms. This approach has only recently become feasible as high-throughput technologies and mass spectrometric analyses of proteins and lipids, together with rigorous bioinformatics, have evolved. Existing high-content data derived from clinically and experimentally derived neural tissues point to convergent pathophysiological pathways during the course of AD, transcending traditional descriptive studies to reach a more integrated and comprehensive understanding of AD pathophysiology, derived systems biomarkers, and "druggable" system nodes. The discussion is continued on the premise that the lack of integration of advanced biomarker technologies and transfertilization from more mature translational research fields (e.g., oncology, immunology, cardiovascular), which satisfy regulatory requirements for an accurate, sensitive, and well-validated surrogate marker of specific pathophysiological processes and/or clinical outcomes, is a major rate-limiting factor for the successful development and approval of effective treatments for AD prevention. We consider the conceptual, scientific, and technical challenges for the discovery-development-validation-qualification process of biomarker tools and analytical algorithms for detection of the earliest pathophysiological processes in asymptomatic individuals at elevated risk during preclinical stages of AD. The most critical need for rapid translation of putative markers into validated (performance) and standardized (harmonized standard operating procedures) biomarker tools that fulfill regulatory requirements (qualify for use in treatment trials: e.g., safety, target engagement, mechanism of action, enrichment, stratification, secondary and primary outcome, surrogate outcome) is the availability of a large-scale worldwide comprehensive longitudinal database that includes the following cohorts: (a) healthy aging, (b) people at elevated risks (genetic/epigenetic/lifestyle/comorbid conditions), and (c) asymptomatic-preclinical/prodromal-mild cognitive impairment/syndromal mild, moderate, or severe AD. Our proposal, as initial strategic steps for integrating markers into future development of diagnostic and therapy trial technologies, is to work toward: (a) creating the essential research and development infrastructure as an international shared resource, (b) building the organizational structure for managing such a multinational shared resource, and (c) establishing an integrated transsectoral multidisciplinary global network of collaborating investigators to help build and use the shared research resource.

Does ionizing radiation influence Alzheimer's disease risk?

Alzheimer's disease (AD) is a human neurodegenerative disease, and its global prevalence is predicted to increase dramatically in the following decades. There is mounting evidence describing the effects of ionizing radiation (IR) on the brain, suggesting that exposure to IR might ultimately favor the development of AD. Therefore better understanding the possible connections between exposure to IR and AD pathogenesis is of utmost importance. In this review, recent developments in the research on the biological and cognitive effects of IR in the brain will be explored. Because AD is largely an age-related pathology, the effects of IR on ageing will be investigated.

Protein clearance mechanisms of alpha-synuclein and amyloid-Beta in lewy body disorders

Protein clearance is critical for the maintenance of the integrity of neuronal cells, and there is accumulating evidence that in most-if not all-neurodegenerative disorders, impaired protein clearance fundamentally contributes to functional and structural alterations eventually leading to clinical symptoms. Dysfunction of protein clearance leads to intra- and extraneuronal accumulation of misfolded proteins and aggregates. The pathological hallmark of Lewy body disorders (LBDs) is the abnormal accumulation of misfolded proteins such as alpha-synuclein (Asyn) and amyloid-beta (Abeta) in a specific subset of neurons, which in turn has been related to deficits in protein clearance. In this paper we will highlight common intraneuronal (including autophagy and unfolded protein stress response) and extraneuronal (including interaction of neurons with astrocytes and microglia, phagocytic clearance, autoimmunity, cerebrospinal fluid transport, and transport across the blood-brain barrier) protein clearance mechanisms, which may be altered across the spectrum of LBDs. A better understanding of the pathways underlying protein clearance-in particular of Asyn and Abeta-in LBDs may result in the identification of novel biomarkers for disease onset and progression and of new therapeutic targets.

Toward a predictive model of Alzheimer's disease progression using capillary electrophoresis-mass spectrometry metabolomics

Alzheimer's disease (AD) is the most prevalent form of dementia with an estimated worldwide prevalence of over 30 million people, and its incidence is expected to increase dramatically with an increasing elderly population. Up until now, cerebrospinal fluid (CSF) has been the preferred sample to investigate central nervous system (CNS) disorders since its composition is directly related to metabolite production in the brain. In this work, a nontargeted metabolomic approach based on capillary electrophoresis-mass spectrometry (CE-MS) is developed to examine metabolic differences in CSF samples from subjects with different cognitive status related to AD progression. To do this, CSF samples from 85 subjects were obtained from patients with (i) subjective cognitive impairment (SCI, i.e. control group), (ii) mild cognitive impairment (MCI) which remained stable after a follow-up period of 2 years, (iii) MCI which progressed to AD within a 2-year time after the initial MCI diagnostic and, (iv) diagnosed AD. A prediction model for AD progression using multivariate statistical analysis based on CE-MS metabolomics of CSF samples was obtained using 73 CSF samples. Using our model, we were able to correctly classify 97-100% of the samples in the diagnostic groups. The prediction power was confirmed in a blind small test set of 12 CSF samples, reaching a 83% of diagnostic accuracy. The obtained predictive values were higher than those reported with classical CSF AD biomarkers (Aβ42 and tau) but need to be confirmed in larger samples cohorts. Choline, dimethylarginine, arginine, valine, proline, serine, histidine, creatine, carnitine, and suberylglycine were identified as possible disease progression biomarkers. Our results suggest that CE-MS metabolomics of CSF samples can be a useful tool to predict AD progression.

Ameliorative effects of curculigoside from Curculigo orchioides Gaertn on learning and memory in aged rats

This study was designed to evaluate the ameliorating effects of curculigoside from Curculigo orchioides Gaertn on learning and memory in aged rats. In the present study, the ameliorating effects of curculigoside were determined through animal behaviour studies (including step-down test and Y-maze test), and the possible mechanisms were explored by evaluation of the activity of acetylcholinesterase (AchE) and determination of the expression of BACE1. Oral adminstration of the curculigoside (20, 40 mg/kg/day) for 14 days can significantly improve the latency and number of errors in aged rats based on the behaviour study results. In addition, the activity of AchE can be decreased by treatment of the curculigoside (10, 20, 40 mg/kg/day). Moreover, the expression of BACE1 can be down-regulated in the hippocampus of aged rats treated with curculigoside. The results of our present work have indicated that curculigoside can improve cognitive function in aged animals, possibly by decreasing the activity of AchE in the cerebra and inhibiting the expression of BACE1 in the hippocampus. In conclusion, our results suggested that curculigoside can be possible developed as a new drug for the treatment of Alzheimer's disease in the future.

Total synthesis of (-)-jiadifenin

As easy as ABCD: (-)-Jiadifenin was synthesized in eighteen reaction steps from 1-[(E)-(4'-bromo-2'-butenyl)oxy]-4-methoxybenzene. Key features of this synthesis include: 1) Ireland-Claisen rearrangement to produce the two contiguous quaternary centers at C5 and C6 simultaneously, 2) intramolecular Pauson-Khand reaction (IMPKR) to concurrently construct the A and B rings, and 3) [2+2] photo-cycloaddition to generate the all-carbon quaternary center at C9.

Clinical utility of neuroprotective agents in neurodegenerative diseases: current status of drug development for Alzheimer's, Parkinson's and Huntington's diseases, and amyotrophic lateral sclerosis

INTRODUCTION

According to the definition of the Committee to Identify Neuroprotective Agents in Parkinson's Disease (CINAPS), "neuroprotection would be any intervention that favourably influences the disease process or underlying pathogenesis to produce enduring benefits for patients" [Meissner W, et al. Trends Pharmacol Sci 2004;25:249-253]. Preferably, neuroprotective agents should be used before or eventually during the prodromal phase of the diseases that could start decades before the appearance of symptoms. Although several symptomatic drugs are available, a disease-modifying agent is still elusive.

AREAS COVERED

The aim of the present review is to give an overview of neuroprotective agents being currently investigated for the treatment of AD, PD, HD and ALS in clinical phases.

EXPERT OPINION

Development of effective neuroprotective therapies resulting in clinically meaningful results is hampered by several factors in all research stages, both conceptual and methodological. Novel solutions might be offered by evaluation of new targets throughout clinical studies, therapies emerging from drug repositioning approaches, multi-target approaches and network pharmacology.

Life- and person-centred help in Mecklenburg-Western Pomerania, Germany (DelpHi): study protocol for a randomised controlled trial

Background

The provision of appropriate medical and nursing care for people with dementia is a major challenge for the healthcare system in Germany. New models of healthcare provision need to be developed, tested and implemented on the population level. Trials in which collaborative care for dementia in the primary care setting were studied have demonstrated its effectiveness. These studies have been conducted in different healthcare systems, however, so it is unclear whether these results extend to the specific context of the German healthcare system.

The objective of this population-based intervention trial in the primary care setting is to test the efficacy and efficiency of implementing a subsidiary support system on a population level for persons with dementia who live at home.

Methods and study design

The study was designed to assemble a general physician-based epidemiological cohort of people above the age of 70 who live at home (DelpHi cohort). These people are screened for eligibility to participate in a trial of dementia care management (DelpHi trial). The trial is a cluster-randomised, controlled intervention trial with two arms (intervention and control) designed to test the efficacy and efficiency of implementing a subsidiary support system for persons with dementia who live at home. This subsidiary support system is initiated and coordinated by a dementia care manager: a nurse with dementia-specific qualifications who delivers the intervention according to a systematic, detailed protocol. The primary outcome is quality of life and healthcare for patients with dementia and their caregivers. This is a multidimensional outcome with a focus on four dimensions: (1) quality of life, (2) caregiver burden, (3) behavioural and psychological symptoms of dementia and (4) pharmacotherapy with an antidementia drug and prevention or suspension of potentially inappropriate medication. Secondary outcomes include the assessment of dementia syndromes, activities of daily living, social support health status, utilisation of health care resources and medication.

Discussion

The results will provide evidence for specific needs in ambulatory care for persons with dementia and will show effective ways to meet those needs. Qualification requirements will be evaluated, and the results will help to modify existing guidelines and treatment paths.

Trial registration

NCT01401582

Cause or Effect: Misregulation of microRNA Pathways in Neurodegeneration

During normal aging or neurodegenerative diseases, neuronal survival and function depend on protein homeostasis, which is regulated by multiple mechanisms, including the microRNA (miRNA) pathway. In different cells types, the absence of Dicer, a key miRNA processing enzyme, leads to neurodegeneration through cell-autonomous and non-cell-autonomous mechanisms. Loss of certain miRNAs also causes neurodegeneration in some model organisms. On the other hand, miRNA expression is misregulated in patients with different neurodegenerative diseases. Thus, the miRNA pathway appears to be essential in the pathogenesis of several age-dependent neurodegenerative conditions; however, our understanding of the underlying mechanism remains rudimentary. The precise causal relationships between specific miRNAs and neurodegeneration in humans need to be further investigated.