ATN cerebrospinal fluid biomarkers in dementia with Lewy bodies: Initial results from the United States Dementia with Lewy Bodies Consortium.

INTRODUCTION: The National Institute on Aging - Alzheimer's Association (NIA-AA) ATN research framework proposes to use biomarkers for amyloid (A), tau (T), and neurodegeneration (N) to stage individuals with AD pathological features and track changes longitudinally. The overall aim was to utilize this framework to characterize pre-mortem ATN status longitudinally in a clinically diagnosed cohort of dementia with Lewy bodies (DLB) and to correlate it with the post mortem diagnosis. METHODS: The cohort was subtyped by cerebrospinal fluid (CSF) ATN category. A subcohort had longitudinal data, and a subgroup was neuropathologically evaluated. RESULTS: We observed a significant difference in Aß42/40 after 12 months in the A+T- group. Post mortem neuropathologic analyses indicated that most of the p-Tau 181 positive (T+) cases also had a high Braak stage. DISCUSSION: This suggests that DLB patients who are A+ but T- may need to be monitored to determine whether they remain A+ or ever progress to T positivity. HIGHLIGHTS: Some A+T- DLB subjects transition from A+ to negative after 12-months. Clinically diagnosed DLB with LBP-AD (A+T+) maintain their positivity. Clinically diagnosed DLB with LBP-AD (A+T+) maintain their positivity. Monitoring of the A+T- sub-type of DLB may be necessary.

Pathological Role of Peptidyl-Prolyl Isomerase Pin1 in the Disruption of Synaptic Plasticity in Alzheimer's Disease.

Synaptic loss is the structural basis for memory impairment in Alzheimer's disease (AD). While the underlying pathological mechanism remains elusive, it is known that misfolded proteins accumulate as ß-amyloid (Aß) plaques and hyperphosphorylated Tau tangles decades before the onset of clinical disease. The loss of Pin1 facilitates the formation of these misfolded proteins in AD. Pin1 protein controls cell-cycle progression and determines the fate of proteins by the ubiquitin proteasome system. The activity of the ubiquitin proteasome system directly affects the functional and structural plasticity of the synapse. We localized Pin1 to dendritic rafts and postsynaptic density (PSD) and found the pathological loss of Pin1 within the synapses of AD brain cortical tissues. The loss of Pin1 activity may alter the ubiquitin-regulated modification of PSD proteins and decrease levels of Shank protein, resulting in aberrant synaptic structure. The loss of Pin1 activity, induced by oxidative stress, may also render neurons more susceptible to the toxicity of oligomers of Aß and to excitation, thereby inhibiting NMDA receptor-mediated synaptic plasticity and exacerbating NMDA receptor-mediated synaptic degeneration. These results suggest that loss of Pin1 activity could lead to the loss of synaptic plasticity in the development of AD.

Arguing against the proposed definition changes of PD.

As members of the Lewy Body Dementia Association Scientific Advisory Council, we aim to address some of the issues raised in the article titled "Time to Redefine PD? Introductory Statement of the MDS Task Force on the Definition of Parkinson's Disease." In particular, we suggest that the 1-year rule distinguishing Parkinson's disease dementia from dementia with Lewy bodies is worth maintaining because it serves an important purpose in clinical practice and clinical and basic science research and when helping the lay community understand the complexity of these different clinical phenotypes. Furthermore, we believe that adding an additional diagnostic label, "PD (dementia with Lewy bodies subtype)," will confuse rather than clarify the distinction between dementia with Lewy bodies and PD or PD dementia, and will not improve management or expedite therapeutic development. We present arguments supporting our contentions. © 2016 The Authors. Movement Disorders published by Wiley Periodicals, Inc. on behalf of International Parkinson and Movement Disorder Society.

Evidence for a role of the rare p.A152T variant in MAPT in increasing the risk for FTD-spectrum and Alzheimer's diseases.

Rare mutations in the gene encoding for tau (MAPT, microtubule-associated protein tau) cause frontotemporal dementia-spectrum (FTD-s) disorders, including FTD, progressive supranuclear palsy (PSP) and corticobasal syndrome, and a common extended haplotype spanning across the MAPT locus is associated with increased risk of PSP and Parkinson's disease. We identified a rare tau variant (p.A152T) in a patient with a clinical diagnosis of PSP and assessed its frequency in multiple independent series of patients with neurodegenerative conditions and controls, in a total of 15 369 subjects. Tau p.A152T significantly increases the risk for both FTD-s (n = 2139, OR = 3.0, CI: 1.6-5.6, P = 0.0005) and Alzheimer's disease (AD) (n = 3345, OR = 2.3, CI: 1.3-4.2, P = 0.004) compared with 9047 controls. Functionally, p.A152T (i) decreases the binding of tau to microtubules and therefore promotes microtubule assembly less efficiently; and (ii) reduces the tendency to form abnormal fibers. However, there is a pronounced increase in the formation of tau oligomers. Importantly, these findings suggest that other regions of the tau protein may be crucial in regulating normal function, as the p.A152 residue is distal to the domains considered responsible for microtubule interactions or aggregation. These data provide both the first genetic evidence and functional studies supporting the role of MAPT p.A152T as a rare risk factor for both FTD-s and AD and the concept that rare variants can increase the risk for relatively common, complex neurodegenerative diseases, but since no clear significance threshold for rare genetic variation has been established, some caution is warranted until the findings are further replicated.

Metabolic and Environmental Biomarkers in Mild Cognitive Impairment and Dementia: An Exploratory Study.

Objective: To determine the frequency with which suspected pathogenic factors, including metals and metabolites that might contribute to Alzheimer's disease (AD), may be found in patients with cognitive impairment through commonly available blood tests. Methods: A variety of serum studies, including metals, ammonia, homocysteine, vitamin B12, folate, thyroid tests, metabolic products, and inflammatory markers, were measured in two cohorts: one meeting mild cognitive impairment (MCI) criteria and the other meeting mild-to-moderate dementia (DE) criteria. Medications these patients received were reviewed. Results: Metal abnormalities were detected in over half the subjects, including evidence of mercury, lead, and arsenic elevation as well as instances of excessive essential metals, iron (Fe), and copper. Some metal aberration was detected in 64% of the DE group and 66% of the MCI group. Females were more likely to have elevated copper, consistent with hormonal effects on copper excretion. Homocysteinemia was the most common abnormality, detected in 71% with DE and 67% with MCI, while methylmalonic acid was not elevated. Slight hyperammonemia was moderately common (38%) suggesting a hepatic factor in this subset. Findings of moderate insulin resistance were present in nearly half (44% DE, 52% MCI). Sixty of 65 (92%) had at least one abnormal biomarker and 60% had two or more. The most common drug taken by the total cohort was proton pump inhibitors at 22% DE and 38% MCI. Conclusions: This study suggests that both toxic metals and excessive vital metals such as copper and iron, as well as common metabolic and hepatic factors are detectable at both stages of MCI and DE. There appears to be a multiplicity of provocative factors leading to DE. Individualized interventions based on these parameters may be a means to reduce cognitive decline leading to DE. A more comprehensive prospective study of these environmental and metabolic factors with corrective early interventions appears warranted.

Association of CSF α-Synuclein Seeding Amplification Assay Results With Clinical Features of Possible and Probable Dementia With Lewy Bodies.

BACKGROUND AND OBJECTIVES: The clinical diagnosis of dementia with Lewy bodies (DLB) depends on identifying significant cognitive decline accompanied by core features of parkinsonism, visual hallucinations, cognitive fluctuations, and REM sleep behavior disorder (RBD). Hyposmia is one of the several supportive features. α-Synuclein seeding amplification assays (αSyn-SAAs) may enhance diagnostic accuracy by detecting pathologic αSyn seeds in CSF. In this study, we examine how different clinical features associate with CSF αSyn-SAA positivity in a large group of clinically diagnosed participants with DLB. METHODS: Cross-sectional and longitudinal CSF samples from the multicentered observational cohort study of the DLB Consortium and similar studies within the Parkinson's Disease Biomarker Program, contributed by academic medical centers in the United States, underwent αSyn-SAA testing. Participants included those clinically diagnosed with DLB and 2 control cohorts. Associations between core DLB features and olfaction with αSyn-SAA positivity were evaluated using logistic regression. RESULTS: CSF samples from 191 participants diagnosed with DLB (mean age 69.9 ± 6.8, 15% female), 50 age-matched and sex-matched clinical control participants, and 49 younger analytical control participants were analyzed. Seventy-two percent (137/191) of participants with DLB had positive αSyn-SAAs vs 4% of the control groups. Among participants with DLB, those who were αSyn-SAA-positive had lower Montreal Cognitive Assessment scores (18.8 ± 5.7 vs 21.2 ± 5.2, p = 0.01), had worse parkinsonism on the Movement Disorders Society Unified Parkinson's Disease Rating Scale part III (33.8 ± 15.1 vs 25.6 ± 16.4, p = 0.001), were more likely to report RBD (114/133 [86%] vs 33/53 [62%], p < 0.0001), and had worse hyposmia on the University of Pennsylvania Smell Identification Test (UPSIT) (94/105 [90%] below 15th percentile vs 14/44 [32%], p < 0.0001). UPSIT percentile had the highest area under the curve (0.87, 95% CI 0.81-0.94) in predicting αSyn-SAA positivity and participants scoring at or below the 15th percentile of age and sex normative values had 18.3 times higher odds (95% CI 7.52-44.6) of having a positive αSyn-SAA test. Among 82 participants with longitudinal CSF samples, 81 (99%) had the same αSyn-SAA result for initial and follow-up specimens. DISCUSSION: A substantial proportion of clinically diagnosed participants with DLB had negative αSyn-SAA results. Hyposmia was the strongest clinical predictor of αSyn-SAA positivity. Hyposmia and αSyn-SAA may have utility in improving the diagnostic assessment of individuals with potential DLB. CLASSIFICATION OF EVIDENCE: This study provided Class III evidence that CSF αSyn-SAA distinguishes patients with clinically diagnosed DLB from normal controls.

Lewy body dementia: caregiver burden and unmet needs.

Lewy body dementia (LBD) is a common cause of dementia but to date, little is known about caregiver burden. The Lewy Body Dementia Association (www.LBDA.org) conducted a web-based survey of 962 caregivers (mean age 56 y; 88% women). The most common initial symptoms were cognitive (48%), motor (39%), or both (13%). Caregivers expressed concerns about fear of future (77%), feeling stressed (54%), loss of social life (52%), and uncertainty about what to do next (50%). Caregivers reported moderate-to-severe burden; 80% felt the people around them did not understand their burden and 54% reported feelings of isolation with spousal caregivers reporting more burden than nonspousal caregivers. Only 29% hired in-home assistance, whereas less than 40% used respite or adult day care, geriatric case managers, or attended a support group meeting. Lack of service utilization occurred despite two-thirds of caregivers reporting medical crises requiring emergency services, psychiatric care, or law enforcement. Caregivers reported preferences for web-based information, directories of LBD expert providers, information on LBD research, and location of local support groups. These findings highlight significant unmet needs for LBD caregivers and provide targets for intervention to reduce caregiver burden. Community resources such as the Lewy Body Dementia Association may serve this end, while also providing practical information and support for caregivers.

Challenges and opportunities for improving the landscape for Lewy body dementia clinical trials.

Lewy body dementia (LBD), including dementia with Lewy bodies and Parkinson's disease dementia, affects over a million people in the USA and has a substantial impact on patients, caregivers, and society. Symptomatic treatments for LBD, which can include cognitive, neuropsychiatric, autonomic, sleep, and motor features, are limited with only two drugs (cholinesterase inhibitors) currently approved by regulatory agencies for dementia in LBD. Clinical trials represent a top research priority, but there are many challenges in the development and implementation of trials in LBD. To address these issues and advance the field of clinical trials in the LBDs, the Lewy Body Dementia Association formed an Industry Advisory Council (LBDA IAC), in addition to its Research Center of Excellence program. The LBDA IAC comprises a diverse and collaborative group of experts from academic medical centers, pharmaceutical industries, and the patient advocacy foundation. The inaugural LBDA IAC meeting, held in June 2019, aimed to bring together this group, along with representatives from regulatory agencies, to address the topic of optimizing the landscape of LBD clinical trials. This review highlights the formation of the LBDA IAC, current state of LBD clinical trials, and challenges and opportunities in the field regarding trial design, study populations, diagnostic criteria, and biomarker utilization. Current gaps include a lack of standardized clinical assessment tools and evidence-based management strategies for LBD as well as difficulty and controversy in diagnosing LBD. Challenges in LBD clinical trials include the heterogeneity of LBD pathology and symptomatology, limited understanding of the trajectory of LBD cognitive and core features, absence of LBD-specific outcome measures, and lack of established standardized biologic, imaging, or genetic biomarkers that may inform study design. Demands of study participation (e.g., travel, duration, and frequency of study visits) may also pose challenges and impact trial enrollment, retention, and outcomes. There are opportunities to improve the landscape of LBD clinical trials by harmonizing clinical assessments and biomarkers across cohorts and research studies, developing and validating outcome measures in LBD, engaging the patient community to assess research needs and priorities, and incorporating biomarker and genotype profiling in study design.

Association of ß-Amyloid Burden With Sleep Dysfunction and Cognitive Impairment in Elderly Individuals With Cognitive Disorders.

Importance: Evidence shows that sleep dysfunction and ß-amyloid (Aß) deposition work synergistically to impair brain function in individuals with normal cognition, increasing the risk of developing dementia later in life. However, whether Aß continues to play an integral role in sleep dysfunction after the onset of cognitive decline in individuals with dementia is unclear. Objective: To determine whether Aß deposition in the brain is associated with subjective measures of sleep quality and cognition in elderly individuals with cognitive disorders. Design, Setting, and Participants: A nested survey study was conducted at the Cognitive Disorders and Comprehensive Alzheimer Disease Center of Thomas Jefferson University Hospital in Philadelphia, Pennsylvania. Participants included patients aged 65 years and older with cognitive disorders verified by neuropsychological testing. Eligible participants were identified from a referral center-based sample of patients who underwent fluorine 18-labeled florbetaben positron emission tomography imaging at Thomas Jefferson University Hospital as part of the multicenter Imaging Dementia-Evidence for Amyloid Scanning study. Data collection and analysis occurred between November 2018 and March 2019. Main Outcomes and Measures: Sleep quality was measured via responses to sleep questionnaires, Aß deposition was measured via fluorine 18-labeled florbetaben positron emission tomography, and cognition was measured via Mini-Mental State Examination (MMSE) performance. Results: Of the 67 eligible participants, 52 (77.6%) gave informed consent to participate in the study. Of the 52 enrolled participants (mean [SD] age, 76.6 [7.4] years), 27 (51.9%) were women. Daytime sleepiness was associated with Aß deposition in the brainstem (B = 0.0063; 95% CI, 0.001 to 0.012; P = .02), but not MMSE performance (B = -0.01; 95% CI, -0.39 to 0.37; P = .96). The number of nocturnal awakenings was associated with Aß deposition in the precuneus (B = 0.11; 95% CI, 0.06 to 0.17; P < .001) and poor MMSE performance (B = -2.13; 95% CI, -3.13 to -1.13; P < .001). Mediation analysis demonstrated an indirect association between Aß deposition and poor MMSE performance that relied on nocturnal awakenings as an intermediary (B = -3.99; 95% CI, -7.88 to -0.83; P = .01). Conclusions and Relevance: Nighttime sleep disruption may mediate the association between Aß and cognitive impairment, suggesting that there is an underlying sleep-dependent mechanism that links Aß burden in the brain to cognitive decline. Further elucidation of this mechanism may improve understanding of disease processes associated with Aß accumulation.

Amyloid deposition begins in the striatum of presenilin-1 mutation carriers from two unrelated pedigrees.

The amyloid cascade hypothesis suggests that the aggregation and deposition of amyloid-beta protein is an initiating event in Alzheimer's disease (AD). Using amyloid imaging technology, such as the positron emission tomography (PET) agent Pittsburgh compound-B (PiB), it is possible to explore the natural history of preclinical amyloid deposition in people at high risk for AD. With this goal in mind, asymptomatic (n = 5) and symptomatic (n = 5) carriers of presenilin-1 (PS1) mutations (C410Y or A426P) that lead to early-onset AD and noncarrier controls from both kindreds (n = 2) were studied with PiB-PET imaging and compared with sporadic AD subjects (n = 12) and controls from the general population (n = 18). We found intense and focal PiB retention in the striatum of all 10 PS1 mutation carriers studied (ages 35-49 years). In most PS1 mutation carriers, there also were increases in PiB retention compared with controls in cortical brain areas, but these increases were not as great as those observed in sporadic AD subjects. The two PS1 mutation carriers with a clinical diagnosis of early-onset AD did not show the typical regional pattern of PiB retention observed in sporadic AD. Postmortem evaluation of tissue from two parents of PS1C410Y subjects in this study confirmed extensive striatal amyloid deposition, along with typical cortical deposition. The early, focal striatal amyloid deposition observed in these PS1 mutation carriers is often is not associated with clinical symptoms.

Caffeine: neuroprotective functions in cognition and Alzheimer's disease.

Alzheimer's disease is a common problem in our elderly population. Although research is leading to improvements in our understanding of the underlying biology, we still have little understanding of the environmental risk factors associated with this disorder. Caffeine, an easily modifiable environmental factor, may have a protective effect on the likelihood of developing Alzheimer's disease. This article reviews the association between caffeine from both a biologic and epidemiologic perspective. Further studies are needed to determine whether caffeine consumption could have a major affect on the development of Alzheimer's disease or age-related cognitive decline.

Neuritic pathology as a correlate of synaptic loss in dementia with lewy bodies.

Synaptic loss is present in Alzheimer's disease and correlates with the severity of dementia. Loss of synapses in dementia with Lewy bodies (DLB) does not correlate as clearly with cognitive status and its cause is unclear. To begin to understand the relationship between cognition and synaptic loss in DLB, we assessed immunoreactivity for the synaptic-terminal specific protein, synaptophysin, in the hippocampus in 14 DLB cases. Quantitative synaptic data were obtained using an Image-Pro semiautomated analysis system. We determined Braak stage, beta-amyloid, Lewy bodies (LBs), and Lewy neurites (LN). We found significant correlations (r = 0.617, P < .01) between Braak stage and synaptophysin score and marginal correlation between LN score and synaptophysin loss ( r = 0.694, P < .06). Correlations of beta-amyloid and of LB density with synaptophysin score were unimpressive. These data support the hypothesis that synaptic loss in DLB is related to neuritic degeneration.

Association between progranulin and beta-amyloid in dementia with Lewy bodies.

Recent studies demonstrated that progranulin plays an integral role in the pathogenesis of frontotemporal dementia. To begin to explore the role of progranulin in dementia with Lewy bodies, we investigate its association with pathologic proteins that characterize this disease. We assessed immunoreactivity for progranulin in medial temporal lobe structures of 12 cases of dementia with Lewy bodies. Similar data were collected for beta-amyloid burden, and alpha-synuclein pathology. Blinded investigators used a 0-3-point scale to quantify progranulin burden. Double labeling for progranulin and beta-amyloid was also performed. We were able to demonstrate progranulin immunoreactivity throughout the medial temporal lobe in all dementia with Lewy body cases. We identified a significant positive correlation (r = 0.606; P = .037) between beta-amyloid burden and progranulin. There was no significant correlation between alpha-synuclein pathology or Braak stage and progranulin. Progranulin and beta-amyloid colocalized in plaques in dementia with Lewy bodies, suggesting that there is likely a biological association between these 2 aggregated proteins.

Potential genetic modifiers of disease risk and age at onset in patients with frontotemporal lobar degeneration and GRN mutations: a genome-wide association study.

BACKGROUND: Loss-of-function mutations in GRN cause frontotemporal lobar degeneration (FTLD). Patients with GRN mutations present with a uniform subtype of TAR DNA-binding protein 43 (TDP-43) pathology at autopsy (FTLD-TDP type A); however, age at onset and clinical presentation are variable, even within families. We aimed to identify potential genetic modifiers of disease onset and disease risk in GRN mutation carriers. METHODS: The study was done in three stages: a discovery stage, a replication stage, and a meta-analysis of the discovery and replication data. In the discovery stage, genome-wide logistic and linear regression analyses were done to test the association of genetic variants with disease risk (case or control status) and age at onset in patients with a GRN mutation and controls free of neurodegenerative disorders. Suggestive loci (p<1 × 10-5) were genotyped in a replication cohort of patients and controls, followed by a meta-analysis. The effect of genome-wide significant variants at the GFRA2 locus on expression of GFRA2 was assessed using mRNA expression studies in cerebellar tissue samples from the Mayo Clinic brain bank. The effect of the GFRA2 locus on progranulin concentrations was studied using previously generated ELISA-based expression data. Co-immunoprecipitation experiments in HEK293T cells were done to test for a direct interaction between GFRA2 and progranulin. FINDINGS: Individuals were enrolled in the current study between Sept 16, 2014, and Oct 5, 2017. After quality control measures, statistical analyses in the discovery stage included 382 unrelated symptomatic GRN mutation carriers and 1146 controls free of neurodegenerative disorders collected from 34 research centres located in the USA, Canada, Australia, and Europe. In the replication stage, 210 patients (67 symptomatic GRN mutation carriers and 143 patients with FTLD without GRN mutations pathologically confirmed as FTLD-TDP type A) and 1798 controls free of neurodegenerative diseases were recruited from 26 sites, 20 of which overlapped with the discovery stage. No genome-wide significant association with age at onset was identified in the discovery or replication stages, or in the meta-analysis. However, in the case-control analysis, we replicated the previously reported TMEM106B association (rs1990622 meta-analysis odds ratio [OR] 0·54, 95% CI 0·46-0·63; p=3·54 × 10-16), and identified a novel genome-wide significant locus at GFRA2 on chromosome 8p21.3 associated with disease risk (rs36196656 meta-analysis OR 1·49, 95% CI 1·30-1·71; p=1·58 × 10-8). Expression analyses showed that the risk-associated allele at rs36196656 decreased GFRA2 mRNA concentrations in cerebellar tissue (p=0·04). No effect of rs36196656 on plasma and CSF progranulin concentrations was detected by ELISA; however, co-immunoprecipitation experiments in HEK293T cells did suggest a direct binding of progranulin and GFRA2. INTERPRETATION: TMEM106B-related and GFRA2-related pathways might be future targets for treatments for FTLD, but the biological interaction between progranulin and these potential disease modifiers requires further study. TMEM106B and GFRA2 might also provide opportunities to select and stratify patients for future clinical trials and, when more is known about their potential effects, to inform genetic counselling, especially for asymptomatic individuals. FUNDING: National Institute on Aging, National Institute of Neurological Disorders and Stroke, Canadian Institutes of Health Research, Italian Ministry of Health, UK National Institute for Health Research, National Health and Medical Research Council of Australia, and the French National Research Agency.

The influence of beta-blockers on delayed memory function in people with cognitive impairment.

Adrenergic signaling is important for the retrieval of intermediate-term contextual and spatial memories. The role of norepinephrine in retrieval requires signaling through beta1-adrenergic receptors in the hippocampus. Environmental cues activate the locus ceruleus, the main adrenergic nucleus of the brain, when an environmental stimulus is memorable. This leads to norepinephrine activation in the hippocampus, which is important for retrieving memories. Although beta-blockers do not impair cognition in normal subjects, this article explores the possibility that central nervous system (CNS)-active beta-blockers could affect delayed memory in patients with cognitive impairment. The authors investigated the influence of beta-blockers on delayed memory function in cognitively impaired patients. There was a trend for worse delayed memory retrieval in patients who were on CNS-active beta-blockers. These data support the notion that common medications used in cognitively impaired elderly patients can worsen cognition and that careful selection of medications may help to maximize retrieval of newly formed memories.

Cognition and amyotrophic lateral sclerosis (ALS).

Amyotrophic lateral sclerosis (ALS) is classically described as a pure motor disease; however, there is growing evidence of a range of cognitive impairment. Cognitive abnormalities include deficiencies in frontal executive skills, varying from mild deficits to meeting criteria for diagnosis of frontotemporal dementia (FTD). Cognitive impairment occurs in sporadic and familial forms of ALS. Patients may present with cognitive deficits before, after, or at the onset of motor neuron disease. Structural and functional imaging studies have shown extramotor cortical degeneration corresponding to levels of frontal executive impairment on neuropsychologic testing. In addition, ALS and a subset of FTD patients display common pathological findings on immunohistochemistry staining. It is believed that these disorders represent a continuum between motor and nonmotor cortical degeneration. The purpose of this article is to review the literature on cognitive deficits in ALS. Identifying changes in cognition is critical for physicians and caregivers of ALS patients, as cognitive decline may interfere with patient compliance. Diagnosis and treatment of cognitive symptoms in ALS patients may improve quality of life.

Presenilin-1 C410Y Alzheimer disease plaques contain synaptic proteins.

Presenilin-1 (PS-1) mutations are associated with familial Alzheimer's disease (AD). Although beta-amyloid (Abeta) plaques in brain tissue are characteristic of AD patients, space occupying "cotton-wool" plaques (CWPs) lacking dense Abeta cores have also been described in patients with mutations in exon 9 of the PS-1 gene. The composition of CWPs has not been fully described. To better elucidate the composition of these space-occupying plaques, we used immunohistochemistry with antibodies to the synaptic proteins synapsin-1 and synaptophysin, as well as antibodies to tau, Abeta(-42), Abeta(-40), ubiquitin, neurofilament, and glial fibrillary acidic protein. Confocal laser scanning microscopy (CLSM) was utilized to further characterize these plaques. CWPs showed increased synapsin-1 and synaptophysin immunoreactivity relative to the background gray matter. Synaptic protein-containing CWPs occurred in all affected MTL regions, including the granule cell layer of the dentate gyrus, where synaptic terminals are usually sparse. These data suggest that in C410Y PS-1 AD patients, CWPs may constitute a major component of synaptic terminal-specific proteins, and that the C410Y PS-1 mutation may influence either synaptic structure or synaptic protein expression.

LR11/SorLA expression is reduced in sporadic Alzheimer disease but not in familial Alzheimer disease.

LR11 is an ApoE receptor that is enriched in the brain. We have shown that LR11 is markedly downregulated in patients with sporadic Alzheimer disease (AD). This finding led us to explore whether reduced LR11 expression reflects a primary mechanism of disease or merely a secondary consequence of other AD-associated changes. Therefore, LR11 expression was assessed in a transgenic mouse model of AD and familial AD (FAD) brains. Immunohistochemistry and immunoblotting of LR11 in PS1/APP transgenic and wild-type mice indicated that LR11 levels are not affected by genotype or accumulation of amyloid pathology. LR11 expression was also evaluated based on immunoblotting and LR11 immunostaining intensity in human frontal cortex in controls, sporadic AD, and FAD, including cases with presenilin-1 (PS1) and presenilin-2 (PS2) mutations. Although LR11 was reduced in sporadic AD, there was no difference in protein level or staining intensity between control and FAD cases. The finding that LR11 expression is unaffected in both a mouse model of AD and autosomal-dominant forms of AD suggests that LR11 is not regulated by amyloid accumulation or other AD neuropathologic changes. We hypothesize that LR11 loss may be specific to sporadic AD and influence amyloid pathology through mechanisms independent of substrate-enzyme interactions regulated by FAD mutations.

Notch-1 immunoexpression is increased in Alzheimer's and Pick's disease.

Notch-1 is a protein that influences cell fate decisions, with its expression occurring primarily during embryogenesis and development. However, Notch-1 is also expressed in the adult brain, in regions with high synaptic plasticity, particularly the hippocampus. Its role in adults is unknown; however, it may impact neurite outgrowth or cell differentiation in adult brain regions undergoing neurogenesis. Notch-1 is increased in Alzheimer's disease (AD); however, its expression in other CNS degenerative diseases has not been described. To begin to define the range of degenerative disorders where Notch-1 expression is altered, we examined Notch-1 immunoreactivity in a variety of neurodegenerative diseases to determine whether its increase is selective for AD. We examined sections of hippocampus from 13 AD, 13 classical Pick's disease (PiD; with Pick bodies), 4 dementia lacking distinctive histopathology (DLDH) and 8 control brains, emphasizing hippocampal (dentate gyrus) pathology. We determined that Notch-1 immunoexpression is increased in AD and PiD relative to control cases. DLDH cases were not significantly different than control cases with respect to Notch-1 expression. Given the increase in Notch-1 immunoexpression in AD and PiD, two diseases where abnormal tau aggregates are present, and the lack of Notch-1 immunoexpression in DLDH (where tau aggregates are absent), we cannot rule out the possibility that tau aggregates are associated with Notch-1 expression in neurodegenerative diseases.

An individualized approach to treatment for alzheimer's disease, pick's disease, and other dementias.

Treatment options for dementia are now available, and increasing numbers of individuals with cognitive disorders are being evaluated for intervention. Little effort is made to select patients who will benefit from the various treatments. Widespread use of medication places patients at risk for developing side effects, which is one reason to target patients likely to benefit from specific interventions. We have limited health care resources and a growing population of elderly individuals with dementia, so our current system of "hit or miss" intervention will become increasingly costly and inefficient. Selecting those likely to benefit from specific interventions would improve efficiency. This article reviews some current approaches for treating dementia and describes a strategy that may help predict which individuals will respond to specific dementia-related treatments. This individualized approach has potential to increase the beneficial effects of medications, reduce the likelihood of side effects, and preserve health care resources.